JP7259740B2 - Reinforcing fiber bundle, method for producing same, and chopped fiber bundle and fiber-reinforced resin molding material using the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to reinforcing fiber bundles and chopped fiber bundles that are excellent in productivity, fluidity during molding, and mechanical properties of molded products, a method for producing the same, and a method for producing a fiber-reinforced resin molding material using the same.

Using a molding material consisting of a bundle-like assembly (hereinafter also referred to as a fiber bundle) of discontinuous reinforcing fibers (for example, carbon fibers) and a matrix resin, a molded product of a desired shape is formed by heat and pressure molding. is widely known. Among such molding materials, a molding material composed of fiber bundles having a large number of single yarns is excellent in fluidity during molding, but the molded product tends to be inferior in mechanical properties. On the other hand, fiber bundles adjusted to an arbitrary number of single yarns are used as the fiber bundles in the molding material in order to achieve both fluidity during molding and mechanical properties of the molded product. As a method of adjusting the number of single yarns of a fiber bundle, for example, Patent Documents 1 and 2 disclose a method of separating fibers using a multi-fiber bundle wound body obtained by winding a plurality of fiber bundles in advance. there is However, since these methods are subject to restrictions on the number of single yarns in the pretreated fiber bundle, the range of adjustment is limited, and it is difficult to adjust the number of single yarns to a desired number.

Further, Patent Documents 3 to 6 disclose a method of longitudinally slitting a fiber bundle into a desired number of single yarns using a disk-shaped rotating blade. In these methods, although it is possible to adjust the number of single yarns by changing the pitch of the rotary blade, the fiber bundle that has been vertically slit in the longitudinal direction has no bundling ability, so the yarn after the vertical slitting is wound on a bobbin. Moreover, handling such as unwinding the fiber bundle from the wound bobbin tends to be difficult. Moreover, when the fiber bundle after the longitudinal slit is conveyed, the split ends of the fiber bundle generated by the longitudinal slit may wind around guide rolls, feed rolls, and the like, making the conveyance difficult. In addition, when used as a molding material, there is a problem of poor flowability due to the large amount of single filaments contained therein.

Patent Literatures 7 and 8 propose reinforcing fibers coated with a polyamide-based sizing agent with the aim of improving process stability and composite physical properties. Although the process stability and composite physical properties were improved, there was a problem of poor productivity due to the time required for drying or denaturation in the sizing agent coating process.

JP-A-2002-255448 Japanese Patent No. 4192041 Japanese Patent No. 5722732 Japanese Patent No. 5996320 Japanese Patent No. 5512908 International publication WO2016/104154 JP 2013-194338 A JP-A-60-221346

Therefore, in view of the above requirements, the present invention provides a reinforcing fiber bundle that is excellent in productivity, fluidity during molding, and mechanical properties of molded products, a chopped fiber bundle thereof, a method for producing the same, and fiber-reinforced resin molding using the same. The task is to provide materials.

In order to solve the above problems, the present invention has the following configurations.
(1) A first sizing agent containing a compound having a functional group such as an epoxy group, a urethane group, an amino group, a carboxyl group, or a mixture thereof on the surface of the reinforcing fiber, and a polyamide resin. A reinforcing fiber bundle characterized by being attached with a second sizing agent containing.
(2) The number of fibers per unit width is 600/mm or more and less than 1,600/mm, and the drape value of the reinforcing fiber bundle is 120 mm or more and 240 mm or less. Reinforcing fiber bundles.
(3) The reinforcing fiber bundle according to (1) or (2), which has a hardness of 39 g or more and 200 g or less.
(4) The reinforcing fiber bundle according to any one of (1) to (3), wherein the polyamide-based resin is attached in an amount of 0.1% by weight or more and 5% by weight or less.
(5) The width change rate W2/W1 is 0.5 or more and 1.1, where W2 is the width of the reinforcing fiber bundle after being immersed in water for 5 minutes and after being removed from the water, and W1 is the width before immersion. The reinforcing fiber bundle according to any one of (1) to (4), characterized by the following.
(6) The reinforcing fiber bundle is immersed in water at 25° C. for 5 minutes, and the drape value D2 in the air after absolute drying is 110 mm or more and 240 mm or less (1) to (5). The reinforcing fiber bundle according to any one of .
(7) The reinforcing fiber bundle according to any one of (1) to (6), in which the divided sections divided into a plurality of bundles and the undivided sections are alternately formed.
(8) The reinforcing fiber bundle according to any one of (1) to (7), characterized in that the splitting treatment sections adjacent to each other with one unsplitting treatment section interposed therebetween include different lengths. .
(9) A chopped fiber bundle obtained by cutting the reinforcing fiber bundle according to any one of (1) to (8), wherein the chopped fiber bundle is immersed in water at 25 ° C. for 5 minutes and then taken out. A chopped fiber bundle, wherein a width change rate W4/W3 is 0.6 or more and 1.1 or less when the width is W4 and the width before immersion is W3.
(10) The chopped fiber bundle according to (9), which is obtained by cutting the reinforcing fiber bundle at a predetermined angle θ (0°<θ<90°) with respect to the longitudinal direction.
(11) A fiber-reinforced resin molding material comprising the chopped fiber bundle according to (9) or (10) and a matrix resin.
(12) The fiber-reinforced resin molding material according to (11), wherein the matrix resin is polyamide.
(13) A water-soluble polyamide is imparted to reinforcing fibers to which a first sizing agent containing any of compounds having functional groups such as epoxy groups, urethane groups, amino groups, carboxyl groups, or a mixture thereof is attached. A method for producing a reinforcing fiber bundle, characterized by:
(14) The method for producing a reinforcing fiber bundle according to (13), characterized by including a widening step (I) of opening and widening the reinforcing fiber bundle (15) Adding a sizing agent to the widened reinforcing fiber bundle The method for producing a reinforcing fiber bundle according to (14), further comprising a step (II) of applying a sizing agent to produce a reinforcing fiber bundle by reacting with a cross-linking agent after applying the sizing agent.
(16) The method for producing a reinforcing fiber bundle according to (15), wherein the cross-linking agent comprises at least one resin selected from melamine resin, urea resin, phenol resin, and epoxy resin.
(17) The method for producing a reinforcing fiber bundle according to any one of (14) to (16), wherein the weight ratio of the cross-linking agent and the sizing agent is 0.02 or more and 1 or less.
(18) In the sizing agent application step (II), the sizing agent is applied so that the total sizing agent adhesion amount of the reinforcing fiber bundle is 0.5% by weight or more and 5% by weight or less, 14) A method for producing a reinforcing fiber bundle according to any one of (17).
(19) Any one of (14) to (18), wherein in the widening step (I), the number of single yarns per unit width of the reinforcing fiber bundle is widened to 1,600/mm or less. The method for producing a reinforcing fiber bundle according to 1.
(20) The method for producing a reinforcing fiber bundle according to any one of (13) to (19), which includes a step of heat-treating the reinforcing fibers to which the water-soluble polyamide has been applied.
(21) The method for producing a reinforcing fiber bundle according to (20), wherein the temperature of the heat treatment is 130 to 350°C.
(22) The method for producing a reinforcing fiber bundle according to (20) or (21), wherein the heat treatment is performed for 0.33 to 15 minutes.
(23) The reinforcing fiber bundle according to any one of (20) to (22), wherein the water-soluble polyamide after the heat treatment has an ester bond and/or a carbon-carbon double bond. Production method.
(24) The water-soluble polyamide is obtained by polymerizing a diamine having a tertiary amino group and/or an oxyethylene group in the main chain and a dicarboxylic acid, (13)- (23) A method for producing a reinforcing fiber bundle according to any one of (23).
(25) The method for producing a reinforcing fiber bundle according to any one of (13) to (24), including a step of separating the reinforcing fibers.
(26) A separating step (III) of inserting a separating means having a plurality of protrusions into the reinforcing fiber bundle while running the reinforcing fiber bundle along the longitudinal direction to generate a separating portion; ,
an entangling step (IV) of forming an entangled portion in which single yarns are entangled at a contact portion between the projecting portion and the reinforcing fiber bundle in at least one of the fiber separating units;
a re-inserting step (V) of extracting the separating means from the reinforcing fiber bundle, passing the separating means through an entangled accumulation portion including the entangled portion, and then thrusting the separating means into the reinforcing fiber bundle again;
Any one of (13) to (25), further comprising a fiber separation treatment step (VI) for alternately forming fiber separation treatment sections divided into a plurality of bundles and non-fiber separation treatment sections. The method for producing the reinforcing fiber bundle according to 1.
(27) Reinforcement according to (26), characterized in that in the fiber separation treatment step (VI), the lengths of the fiber separation treatment sections adjacent to each other with one non-fiber separation treatment section interposed therebetween include different lengths. A method for producing a fiber bundle.

According to the method for manufacturing a reinforcing fiber bundle according to the present invention, it is possible to increase the productivity of the separated and morphologically stabilized reinforcing fiber bundle. When the obtained reinforcing fiber bundle is cut/dispersed to form a discontinuous fiber intermediate base material, it is possible to develop fluidity during molding and mechanical properties of the molded article in a well-balanced manner.

FIG. 2 is a schematic plan view showing an example of a split fiber bundle obtained by subjecting the fiber bundle to splitting treatment in the method for manufacturing a reinforcing fiber bundle according to the present invention. An example of inserting a separating means into a running fiber bundle is shown, (A) is a schematic plan view, and (B) is a schematic side view. An example of a movement cycle for inserting a moving separating means into a fiber bundle is shown, (A) is a schematic plan view, and (B) is a schematic side view. FIG. 10 is a schematic explanatory diagram showing another example of a movement cycle for inserting a moving separating means into a fiber bundle; FIG. 4 is an explanatory diagram showing an example of a movement cycle for inserting the rotating fiber separating means; FIG. 4 is a process diagram showing an example of the timing of the step of applying a sizing agent in the method for producing a split fiber bundle. FIG. 4 is a process chart showing an example of the timing of the sizing agent application process in the split fiber bundle manufacturing method including the fiber bundle widening process. FIG. 3 is a process chart showing an example of timing of a sizing agent application step including a sizing agent application step and a drying step in a method for producing a split fiber bundle. FIG. 4 is a process chart showing another timing example of the sizing agent applying step including the sizing agent applying step and the drying step in the method for producing the split fiber bundle. FIG. 4 is a process chart showing an example of the timing of a sizing agent application process including a sizing agent application process and a drying process in a split fiber bundle manufacturing method including a fiber bundle widening process. FIG. 10 is a process chart showing another timing example of the sizing agent applying step including the sizing agent application step and the drying step in the split fiber bundle manufacturing method including the fiber bundle widening step. FIG. 4 is a schematic explanatory diagram showing a method of measuring a drape value;

Although there are no restrictions on the types of reinforcing fibers used in the present invention, carbon fibers, glass fibers, aramid fibers, and metal fibers are preferred. Among them, carbon fiber is preferred. The carbon fiber is not particularly limited, but for example, polyacrylonitrile (PAN)-based, pitch-based, rayon-based carbon fibers can be preferably used from the viewpoint of improving mechanical properties and reducing the weight of fiber-reinforced thermoplastic resins. These may be used singly or in combination of two or more. Among them, PAN-based carbon fibers are more preferable from the viewpoint of the balance between strength and elastic modulus of the resulting fiber-reinforced thermoplastic resin.

The single fiber diameter of the reinforcing fibers is preferably 0.5 μm or more, more preferably 2 μm or more, and even more preferably 4 μm or more. Further, the single fiber diameter of the reinforcing fibers is preferably 20 μm or less, more preferably 15 μm or less, and even more preferably 10 μm or less. The strand strength of the reinforcing fibers is preferably 3.0 GPa or higher, more preferably 4.0 GPa or higher, and even more preferably 4.5 GPa or higher. The strand elastic modulus of the reinforcing fiber is preferably 200 GPa or higher, more preferably 220 GPa or higher, even more preferably 240 GPa or higher. If the strand strength or elastic modulus of the reinforcing fiber is within this range, the mechanical properties of the molded product can be enhanced.

In the step of widening the reinforcing fiber bundle, the number of single yarns per unit width of the widened reinforcing fiber bundle is preferably 600/mm or more, more preferably 700/mm or more, and even more preferably 800/mm or more. If it is less than 600 lines/mm, there is a concern that the fluidity of the molding material may be poor. The number of single yarns per unit width of the reinforcing fiber bundle is preferably 1,600/mm or less, more preferably 1,400/mm or less, and even more preferably 1,200/mm or less. If it exceeds 1,600 lines/mm, there is a concern that the mechanical properties of the molded product will be inferior. A method for deriving the number of single yarns per unit width of the reinforcing fiber bundles constituting the fiber-reinforced resin molding material will be described later.

In the step of widening the reinforcing fibers, the thickness of the widened reinforcing fiber bundle is preferably 0.01 mm or more, more preferably 0.03 mm or more, and even more preferably 0.05 mm or more. If it is less than 0.01 mm, there is a concern that the fluidity of the molding material may be poor. Also, the thickness of the reinforcing fiber bundle is preferably 0.2 mm or less, more preferably 0.18 mm or less, and even more preferably 0.16 mm or less. If it exceeds 0.2 mm, there is a concern that the mechanical properties of the molded product may deteriorate.

The sizing agent used in the present invention consists of a primary sizing agent and a secondary sizing agent. A primary sizing agent is first applied to the reinforcing fiber bundles, and then a secondary sizing agent is applied to the reinforcing fiber bundles. The secondary sizing agent preferably contains a water-soluble polyamide as a main component, and the water-soluble polyamide is polycondensed from a diamine having a tertiary amino group and/or an oxyethylene group in the main chain and a carboxylic acid. A polyamide resin obtained by the above diamine containing a tertiary amino group in the main chain such as N,N'-bis(γ-aminopropyl)piperazine, N-(β-aminoethyl)piperazine, etc. having a piperazine ring Monomers, alkyldiamines containing oxyethylene groups in the backbone such as oxyethylenealkylamines are useful. Dicarboxylic acids include adipic acid and sebacic acid. In order to lower the heat treatment temperature and shorten the heat treatment time, the primary sizing agent is either a compound having a functional group such as an epoxy group, a urethane group, an amino group, or a carboxyl group, or any of them. A mixture of Moreover, it is preferable to add a solvent or a cross-linking agent to the reinforcing fiber surface layer in advance. Although the type of the cross-linking agent is not particularly limited, it is preferably at least one resin selected from melamine resin, urea resin, phenol resin, and epoxy resin. The lower limit of the weight ratio of the cross-linking agent to the sizing agent is preferably 0.02 or more, more preferably 0.03 or more, and even more preferably 0.04 or more. On the other hand, the upper limit of the weight ratio of the cross-linking agent to the sizing agent is preferably 1 or less, more preferably 0.8 or less, and even more preferably 0.6 or less. Within this range, the heat treatment temperature can be lowered and the heat treatment time can be shortened.

The water-soluble polyamide of the present invention may be a copolymer. Examples of copolymer components include lactams such as α-pyrrolidone, α-piperidone, ε-caprolactam, α-methyl-ε-caprolactam, ε-methyl-ε-caprolactam, and ε-laurolactam. Copolymerization or multi-component copolymerization is also possible, but the copolymerization ratio is determined within a range that does not interfere with the physical property of water solubility. Preferably, the polymer does not completely dissolve in water unless the proportion of the copolymer component having a lactam ring is within 30% by weight.

However, even a poorly water-soluble polymer with a copolymer component ratio outside the above range becomes more soluble in water and usable when the solution is acidified with an organic or inorganic acid. Examples of organic acids include acetic acid, chloroacetic acid, propionic acid, maleic acid, oxalic acid and fluoroacetic acid. Examples of inorganic acids include common mineral acids such as hydrochloric acid, sulfuric acid and phosphoric acid.

This water-soluble polyamide may be used as a primary sizing agent for reinforcing fiber bundles to which no sizing agent is applied, or may be used as a secondary sizing agent for reinforcing fiber bundles to which a sizing agent is previously applied.

The amount of the total sizing agent applied to the reinforcing fiber bundle is preferably 5% by weight or less, more preferably 4% by weight or less, and even more preferably 3% by weight or less. If the amount of the sizing agent adhered exceeds 5% by weight, the fiber bundle loses flexibility and becomes too hard, which may hinder smooth winding and unwinding of the bobbin. In addition, there is a possibility that single filament splitting occurs during cutting, and an ideal chopped fiber bundle shape cannot be obtained. The amount of the sizing agent attached is preferably 0.1% by weight or more, more preferably 0.3% by weight or more, and even more preferably 0.5% by weight or more.

When the amount of the sizing agent attached is less than 0.1% by weight, the adhesiveness between the matrix and the reinforcing fibers tends to decrease when trying to produce a molded product, and the mechanical properties of the molded product may decrease. . In addition, the filaments may be loosened and fuzz may be generated, resulting in deterioration of the unwinding property from the bobbin or winding on the nip roller or cutter blade. A method for deriving the adhesion amount of the sizing agent will be described later.

The sizing agent is preferably homogeneously attached to the surface of the reinforcing fibers. The method for homogeneously attaching the sizing agent is not particularly limited. , a method in which the fiber bundle is immersed in the sizing agent treatment liquid via a roller in the polymer solution, a method in which the fiber bundle is brought into contact with a roller to which the sizing agent treatment liquid has adhered, and a sizing agent treatment liquid is atomized and sprayed onto the fiber bundle. There are methods. At this time, it is preferable to control the concentration of the sizing agent treatment liquid, temperature, yarn tension, etc. so that the amount of the sizing agent active ingredient adhered to the fibers is uniformly within an appropriate range. Further, it is more preferable to vibrate the fiber bundle with ultrasonic waves when applying the sizing agent.

Any method such as heat treatment, air drying, or centrifugation may be used to remove the solvent such as water or alcohol in the sizing agent attached to the reinforcing fiber bundle, but heat treatment is preferred from the viewpoint of cost. As heating means for heat treatment, for example, hot air, a hot plate, a roller, an infrared heater, or the like can be used. This heat treatment condition is also important, and is related to the ease of handling and the quality of adhesion to the matrix material. That is, the heat treatment temperature and time after applying the sizing agent to the fiber bundle should be adjusted according to the components and amount of the sizing agent. In the case of the water-soluble polyamide, from the viewpoint of preventing thermal deterioration, it is preferable to heat-treat after drying at room temperature to 180° C. to remove moisture. The lower limit of the heat treatment temperature is preferably 130°C or higher, more preferably 200°C or higher. The upper limit of the heat treatment temperature is preferably 350°C or lower, more preferably 280°C or lower. This heat treatment temperature is the temperature at which the water-soluble polyamide undergoes self-crosslinking or loses its water-solubility due to oxygen in the air. The polyamide after this treatment may have ester bonds and/or carbon-carbon double bonds. Heat treatment makes the water-soluble polymer insoluble and loses its hygroscopicity, so the strands that bundle the filaments are not sticky and workability in post-processing is improved. Can provide bundles. The heat treatment time is preferably 0.3 minutes or longer. Also, the time is preferably 10 minutes or less, more preferably 6 minutes or less, and even more preferably 2 minutes or less. Within this range, the line speed can be increased and the productivity can be enhanced. After the heat treatment, the hardness of the fiber bundle can be further increased by performing an aging treatment in an atmosphere of 23±5°C.

Sizing agents using this water-soluble polyamide resin have excellent affinity with various matrix materials and significantly improve the physical properties of composites. It has an excellent adhesion improvement effect in resins.

When the water-soluble polyamide is used as the secondary sizing agent, it may be applied to the reinforcing fiber bundle to which the primary sizing agent has been applied in the same manner as described above, or may be applied during the manufacturing process of the reinforcing fiber bundle. In the production of a specific reinforcing fiber bundle, to give an example of the application of the sizing agent at any time during the manufacturing process of the reinforcing fiber bundle, for example, the sizing agent is added to the solvent (including the dispersion medium when dispersed) The sizing agent can be applied to the fiber bundle by preparing a dissolved (including dispersed) sizing agent treatment liquid, applying the sizing agent treatment liquid to the fiber bundle, and then drying and evaporating the solvent to remove it. commonly done.

The thermal decomposition starting temperature of the sizing agent in the present invention is preferably 200° C. or higher, more preferably 250° C. or higher, and even more preferably 300° C. or higher. A method for deriving the thermal decomposition start temperature will be described later.

The drape value D1 of the reinforcing fiber bundle after application of the sizing agent used in the present invention is preferably 120 mm or more, preferably 145 mm or more, and more preferably 170 mm or more. If the drape value D1 is less than 120 mm, the filaments may be loosened and fluff may be generated, resulting in deterioration of unwindability from the bobbin and winding on the nip roller and cutter blade. Further, the drape value D1 of the reinforcing fiber bundle after application of the sizing agent is preferably 240 mm or less, preferably 230 mm or less, and more preferably 220 mm or less. When the drape value D1 exceeds 240 mm, the fiber bundle lacks flexibility and becomes too hard, which may hinder smooth winding and unwinding of the bobbin. In addition, there is a possibility that single filament cracking may occur during cutting, and an ideal chopped fiber bundle shape cannot be obtained. A method for deriving the drape value of the reinforcing fiber bundle will be described later.

Next, the reinforcing fiber bundle whose drape value D1 was measured was immersed in water at 25° C. for 5 minutes, taken out, and dried completely. The lower limit of the drape value D2 (bundle hardness) is preferably 110 mm or more, more preferably 145 mm or more, and even more preferably 170 mm or more. The upper limit of the drape value D1 (bundle hardness) is preferably 240 mm or less, more preferably 230 mm or less, and even more preferably 220 mm or less. If the drape value D2 is less than 110 mm, the filaments may become loose and fluff may be generated, resulting in deterioration of unwindability from the bobbin and winding on the nip roller and cutter blade. On the other hand, when the drape value D2 exceeds 240 mm, the fiber bundle lacks flexibility and becomes too hard, which may hinder smooth winding and unwinding of the bobbin. In addition, single filament splitting may occur during cutting, and the ideal chopped fiber configuration may not be obtained.

The bundle hardness of the reinforcing fiber bundle after application of the sizing agent used in the present invention is preferably 39 g or more, more preferably 70 g or more, and even more preferably 120 g or more. If the hardness is less than 39 g, the filaments may be loosened and fuzz may be generated, resulting in deterioration of unwindability from the bobbin and winding on the nip roller and cutter blade. The bundle hardness of the reinforcing fiber bundles constituting the fiber-reinforced thermoplastic resin molding material is preferably 200 g or less, more preferably 190 g or less, even more preferably 180 g or less. If the hardness of the reinforcing fiber bundle exceeds 200 g, the windability of the reinforcing fiber bundle with a winder is lowered, and the effects of the present invention are not exhibited. A method for deriving the bundle hardness of the reinforcing fiber bundle will be described later.

The width before immersion in water of the reinforcing fiber bundle after application of the sizing agent used in the present invention is W1, the reinforcing fiber bundle is immersed in water at 25 ° C. for 5 minutes, taken out, and drained for 1 minute. , the width change rate W2/W1 of the reinforcing fiber bundle is preferably 0.5 or more, more preferably 0.6 or more, and still more preferably 0.7 or more. If the width change rate W2/W1 of the reinforcing fiber bundle is less than 0.5, the sizing agent adhered to the reinforcing fiber bundle remains water-soluble, so that the fiber is separated after the fiber separation treatment. When the fiber bundle is re-aggregated, it becomes difficult to maintain the shape of the fiber bundle adjusted to the optimum number of single yarns. If the form of the fiber bundle adjusted to the optimum number of single yarns cannot be maintained, the divided fiber bundle is cut/dispersed to form an intermediate base material of the discontinuous fiber bundle in an optimum form. becomes difficult, and it becomes difficult to develop the fluidity during molding and the mechanical properties of the molded product in a well-balanced manner. Also, the width change rate W2/W1 is preferably 1.1 or less. If the width change rate W2/W1 exceeds 1.1, the fiber bundle lacks flexibility and becomes too hard, which may hinder smooth winding and unwinding of the bobbin. In addition, there is a possibility that single filament splitting occurs during cutting, and an ideal chopped fiber bundle shape cannot be obtained. A method for deriving the width change rate W2/W1 of the reinforcing fiber bundle will be described later.

Next, the split fiber bundle in the present invention will be described. A split fiber bundle is a reinforcing fiber in which a split treatment section divided into a plurality of bundles and an unsplit treatment section are alternately formed along the longitudinal direction of a fiber bundle composed of a plurality of single filaments. A sizing agent is applied to the reinforcing fiber bundle. The unsplit treated section may be continuous or discontinuous in the width direction of the split fiber bundle. In addition, the lengths of the fiber-dividing sections adjacent to each other with one non-fiber-fiber-dividing section interposed therebetween may be the same or different.

A method for producing a split fiber bundle according to the present invention will be described. FIG. 1 shows an example of a split fiber bundle obtained by subjecting a fiber bundle to a splitting treatment in the present invention, and FIG. 2 shows an example of the splitting treatment. A method for producing a split fiber bundle according to the present invention will be described with reference to FIG. FIG. 2 is (A) a schematic plan view and (B) a schematic side view showing an example in which a separating means is thrust into a traveling fiber bundle. The fiber bundle traveling direction a (arrow) in the drawing is the longitudinal direction of the fiber bundle 100, and represents that the fiber bundle 100 is continuously supplied from a fiber bundle supply device (not shown).

The fiber separating means 200 includes a protruding portion 210 having a protruding shape that can be easily inserted into the fiber bundle 100. A fiber separating portion 150 that protrudes into the running fiber bundle 100 and is substantially parallel to the longitudinal direction of the fiber bundle 100. to generate Here, it is preferable that the fiber separating means 200 pierce the fiber bundle 100 in a direction along the side surface thereof. The side surface of the fiber bundle is the vertical surface at the end of the cross section when the cross section of the fiber bundle has a flat shape such as a horizontally long ellipse or a horizontally long rectangle (for example, the fiber bundle 100 shown in FIG. corresponding to the side surface). Moreover, the protruding portion 210 provided may be one per one fiber separating means 200, or may be plural. In the case where one separating means 200 has a plurality of projecting portions 210, the frequency of wear of the projecting portions 210 is reduced, so that the replacement frequency can also be reduced. Furthermore, it is also possible to use a plurality of separating means 200 simultaneously according to the number of fiber bundles to be separated. The plurality of fiber separating means 200 can be arranged in parallel, staggered, out of phase, etc., and the plurality of projecting portions 210 can be arranged arbitrarily.

When the fiber bundle 100 made up of a plurality of single yarns is divided into divided bundles with a smaller number by the separating means 200, the plurality of single yarns are substantially not aligned in the fiber bundle 100. Since there are many entangled portions at the single yarn level, an entangled portion 160 where the single yarns are entangled may be formed near the contact portion 211 during the fiber separation process.

Here, forming the entangled portion 160 means, for example, forming (moving) the entanglement of single filaments that have previously existed in the separating section to the contact portion 211 by the separating means 200, or For example, the means 200 may be used to form (manufacture) a new aggregate in which single yarns are entangled.

In the split fiber bundle of the present invention, since a sizing agent is applied to the surface of the reinforcing fibers, the reinforcing fibers are restrained to each other, and the generation of single yarns due to rubbing or the like during the splitting process can be greatly reduced. , and the occurrence of the entangled portion 160 described above can be greatly reduced.

After the fiber separation processing portion 150 is generated in an arbitrary range, the fiber separation means 200 is extracted from the fiber bundle 100. - 特許庁By this extraction, the fiber separation processing section 110 to which the fiber separation processing is applied is generated, and at the same time, the entangled portion 160 generated as described above is accumulated at the end portion of the fiber separation processing section 110, and the entangled portion 160 is accumulated. is generated by the entanglement accumulation unit 120 accumulated. Further, the fluff generated from the fiber bundle during the fiber separation process forms a fluff pool 140 in the vicinity of the entangled accumulation portion 120 during the fiber separation process.

After that, by thrusting the separating means 200 into the fiber bundle 100 again, the non-fiber-dividing section 130 is generated, and the fiber-dividing section 110 and the non-fiber-dividing section 130 are formed along the longitudinal direction of the fiber bundle 100. Split fiber bundles 180 arranged alternately are formed. In the split fiber bundle 180 of the present invention, the content of the non-split section 130 is preferably 3% or more and 50% or less. Here, the content rate of the non-split sections 130 is defined as the ratio of the total generated length of the un-split sections 130 to the total length of the fiber bundle 100 . If the content of the unsplit fiber bundle 130 is less than 3%, the flowability when the split fiber bundle 180 is cut/dispersed and used for molding as an intermediate base material of the discontinuous fiber bundle is poor, and the content of the unsplit fiber bundle 130 is less than 50%. If it exceeds, the mechanical properties of the molded article molded using it will be deteriorated.

As for the length of each section, it is preferable that the length of the fiber separation treatment section 110 is 30 mm or more and 1500 mm or less, and the length of the non-fiber separation treatment section 130 is 1 mm or more and 150 mm or less. is preferred.

The running speed of the fiber bundle 100 is preferably a stable speed with little fluctuation, more preferably a constant speed.

The fiber separating means 200 is not particularly limited as long as the object of the present invention can be achieved, and preferably has a sharp shape such as a metal needle or a thin plate. As for the separating means 200, it is preferable to provide a plurality of separating means 200 in the width direction of the fiber bundle 100 to be subjected to the separating process. It can be arbitrarily selected according to the number F of constituent single yarns. The number of separating means 200 is preferably (F/10,000−1) or more and less than (F/50−1) in the width direction of the fiber bundle 100 . If the number is less than (F/10,000-1), it is difficult to improve the mechanical properties when the reinforcing fiber composite material is formed in a post-process. Sometimes there is a risk of thread breakage or fluffing.

The present invention is not limited to the case where the fiber bundle runs, as shown in FIG. A method may also be used in which the fiber separating section 150 is generated while the fiber 200 is running along the fiber bundle 100 (arrow (2)), and then the fiber separating means 200 is removed (arrow (3)). After that, as shown in FIG. 4(A), after the stationary fiber bundle 100 is moved by a predetermined distance at the timing indicated by arrows (3) and (4), the fiber separating means 200 is returned to its original position. (Arrow (4)), or as shown in FIG. 4B, the fiber bundle 100 is not moved, and the fiber separating means 200 moves (arrow (4) )).

When performing the separating process while moving the fiber bundle 100 by a predetermined distance, as shown in FIG. 3B or FIG. The operation time indicated by (2)) and the time until the separating means 200 is pulled out and thrust into the fiber bundle again (the operation time indicated by arrows (3), (4), and (1)) are controlled. preferably. In this case, the direction of movement of the separating means 200 repeats (1) to (4) in the figure.

Further, when the fiber bundle 100 is not moved and the fiber separating means 200 is moved until the fiber bundle 100 passes through the entanglement accumulation portion 120, the fiber separation process is performed as shown in FIG. 4(B). , the time required for the separating processing time during which the separating means is inserted (duration of operation indicated by arrow (2) or arrow (6)), and the time required for removing the separating means 200 and inserting it into the fiber bundle again (arrow ( 3), (4), (5) or times of operation indicated by arrows (3), (4), (1)) are preferably controlled. In this case as well, the direction of movement of the separating means 200 repeats (1) to (4) in the figure.

In this way, the separating section 200 alternately forms the separating section and the unseparated section, and separates the unseparated section so that the ratio of the unseparated section to the total length of the fiber bundle is within a predetermined range. A fiber bundle is produced.

Note that depending on the state of entanglement of the single yarns forming the fiber bundle 100, an unsplit fiber section of an arbitrary length may be secured (for example, in FIG. It is also possible to resume the fiber separation process from the vicinity of the terminal end of the fiber separation process section without processing the next fiber separation process section 150 after securing the process section 130 . For example, as shown in FIG. 4A, when the fiber bundle 100 is intermittently moved while the fiber separation process is performed, the fiber separation means 200 performs the fiber separation process (arrow (2)), and then the fiber By making the movement length of the bundle 100 shorter than the length of the previous fiber separation treatment, the position (arrow (1)) where the fiber separation means 200 is inserted again overlaps the fiber separation treatment section of the previous fiber separation treatment. be able to. On the other hand, as shown in FIG. 4(B), when the separating means 200 itself is moved while the separating process is performed, once the separating means 200 is pulled out (arrow (3)), it is moved by a predetermined length. The separating means 200 can be pushed into the fiber bundle again (arrow (5)) without causing the fiber bundle to move (arrow (4)).

When the plurality of single yarns forming the fiber bundle 100 are entangled with each other, such a fiber separation process does not substantially pull the single yarns in the fiber bundle. With respect to the direction, even if the separating means 200 is inserted again into a position that has already undergone a separating process or the same position as the position where the separating means 200 was extracted, the position to be inserted at the single yarn level is likely to shift, The formed fiber separation treatment section can exist as separate fiber separation treatment sections without continuing the separated state (void).

The length of the segmentation section (segmentation distance 170) that is segmented per segmentation process is preferably 30 mm or more and less than 1,500 mm, although it depends on the entangled state of the single yarns of the fiber bundle to be subjected to the segmentation process. If it is less than 30 mm, the effect of the fiber separation treatment is insufficient, and if it is 1,500 mm or more, depending on the reinforcing fiber bundle, there is a risk of yarn breakage or fluffing.

Furthermore, when a plurality of separating means 200 are provided, a plurality of alternately formed fiber separation treatment sections and non-fiber separation treatment sections may be provided substantially parallel to the width direction of the fiber bundle. At this time, as described above, the plurality of fiber separating means 200 can be arranged in parallel, staggered, out of phase, or the like, and the plurality of protruding portions 210 can be arranged arbitrarily.

Furthermore, multiple protrusions 210 can be independently controlled. Although the details will be described later, it is also preferable that each protrusion 210 performs the fiber separation process independently depending on the time required for the fiber separation process and the pressing force detected by the protrusion 210 .

In either case, the fiber bundle is unwound from a fiber bundle unwinding device (not shown) or the like arranged upstream in the fiber bundle running direction. Regarding the unwinding direction of the fiber bundle, it is possible to use a horizontal method in which the fiber bundle is drawn out in a direction perpendicular to the bobbin rotation axis, or a vertical method in which the fiber bundle is drawn out in the same direction as the bobbin (paper tube) rotation axis. Considering this, the lateral extension method is preferable.

In addition, the bobbin can be installed in any direction during unwinding. Among other things, when the bobbin is pierced into the creel and the end face of the bobbin on the side that is not the fixing surface of the creel rotation shaft faces in a direction other than the horizontal direction, the fiber bundle is held in a state where a certain amount of tension is applied. preferably. If the fiber bundle does not have a constant tension, the fiber bundle slips and falls from the package (a winding body in which the fiber bundle is wound on the bobbin), or the fiber bundle that has separated from the package winds around the creel rotating shaft. Therefore, it is conceivable that unwinding becomes difficult.

In addition to using a creel as a method of fixing the rotation axis of the unwinding package, the package is placed on two parallel rollers and rolled on the rollers. A surface unwinding method, in which the fiber bundle is unwound in this manner, is also applicable.

In the case of unwinding using a creel, a belt is attached to the creel, one of which is fixed, and the other is hung with a weight or pulled by a spring to apply a brake to the creel, thereby allowing the unwound fiber bundle to A method of applying tension is conceivable. In this case, varying the braking force in accordance with the winding diameter is effective as means for stabilizing the tension.

Further, the number of single yarns after splitting can be adjusted by a method of widening the fiber bundle and the pitch of a plurality of splitting means arranged side by side in the width direction of the fiber bundle. By reducing the pitch of the separating means and providing more separating means in the width direction of the fiber bundle, it is possible to separate a so-called fine bundle, which has a smaller number of single yarns. In addition, without narrowing the pitch of the separating means, the number of single yarns can be adjusted by widening the fiber bundle before performing the separating process and separating the widened fiber bundle by more separating means. is.

Here, widening means processing for widening the width of the fiber bundle 100 . The widening method is not particularly limited, and is preferably a vibratory widening method in which a vibrating roll is passed through, an air widening method in which compressed air is blown, or the like.

In the present invention, the separating section 150 is formed by repeating the insertion and withdrawal of the separating means 200 . In this case, it is preferable to set the timing for re-insertion based on the elapsed time after the separating means 200 is pulled out. Moreover, it is preferable to set the timing of pulling out again based on the elapsed time after the separating means 200 is inserted. By setting the timing of thrusting and/or withdrawing by time, it is possible to generate the fiber separation processing section 110 and the non-fiber separation processing section 130 with a predetermined distance interval, and the fiber separation processing section 110 and the non-fiber separation processing section 130 can be generated. It is also possible to arbitrarily determine the ratio of the fiber-treated section 130 . Also, the predetermined time interval may be always the same, but it may be lengthened or shortened according to the distance that the fiber separation process has progressed, or depending on the state of the fiber bundle at that time, for example, the fiber bundle If there is little fluff or entanglement of the single yarns originally, the predetermined time interval may be shortened or changed according to the situation.

When the fiber bundle 100 is thrust into the fiber bundle 100, the entangled portion 160 that is generated continues to push the protruding portion 210 as the fiber separation process progresses, so that the fiber dividing means 200 receives a pressing force from the entangled portion 160. .

As described above, the plurality of single yarns are not substantially aligned in the fiber bundle 100, and there are many portions that are entangled at the single yarn level, and furthermore, there are many entangled portions in the longitudinal direction of the fiber bundle 100. There are cases where there are few places. The pressing force during the fiber separation treatment rises quickly at locations where the single yarns are entangled, and conversely, the pressing force rises slowly at locations where the single yarns are entangled. Therefore, it is preferable that the separating means 200 of the present invention include pressing force detecting means for detecting the pressing force from the fiber bundle 100 .

Since the tension of the fiber bundle 100 may change before and after the separating means 200, at least one tension detecting means for detecting the tension of the fiber bundle 100 may be provided near the separating means 200. A plurality of them may be provided to calculate the tension difference. The means for detecting the pressing force, the tension, and the difference in tension can be provided individually, or any of them can be provided in combination. Here, the tension detection means for detecting tension is preferably arranged in a range separated by 10 to 1,000 mm from the separating means 200 along the longitudinal direction of the fiber bundle 100 in at least one of the front and rear directions.

It is preferable to control withdrawal of the fiber separating means 200 according to the detected values of the pressing force, the tension, and the tension difference. It is more preferable to perform control so that the separating means 200 is pulled out when an arbitrarily set upper limit is exceeded as the detected value rises. It is preferable to set the upper limits of the pressing force and tension in the range of 0.01 to 5 N/mm, and the tension difference in the range of 0.01 to 0.8 N/mm. Note that the upper limit value may vary within a range of ±10% depending on the state of the fiber bundle. Here, the unit (N/mm) of the pressing force, tension, and tension difference indicates the force acting per width of the fiber bundle 100 .

When the pressing force, tension, and tension difference are below the upper limit range, the pressing force, tension, and tension difference for withdrawing the separating means 200 are reached immediately after the separating means 200 is inserted, so a sufficient separating distance is required. is not removed, the fiber separation treatment section 110 becomes too short, and the fiber bundle subjected to the fiber separation treatment to be obtained in the present invention cannot be obtained. On the other hand, if the range of the upper limit is exceeded, the pressing force and tension for extracting the separating means 200 after the separating means 200 is pushed in, and the number of single yarn cuts in the fiber bundle 100 before reaching the tension difference increase. Problems such as splitting-treated fiber bundles popping out in the form of split ends and increased fluff are likely to occur. The protruding split ends tend to wind up on the rolls being conveyed, and the fluffs accumulate on the drive rolls to cause the fiber bundle to slip, thus easily causing conveyance failures.

Unlike the case of controlling the withdrawal timing of the separating means 200 by time, in the case of detecting the pressing force, the tension, and the tension difference, the separation process is performed before a force sufficient to cut the fiber bundle 100 is applied during the separating process. Since the means 200 is pulled out, no excessive force is applied to the fiber bundle 100, and continuous fiber separation processing becomes possible.

Furthermore, the fiber bundle 100 has a long fiber separation treatment section 110 and a stable shape of the entanglement accumulation portion 120 in the longitudinal direction while suppressing the occurrence of branch cuts and fluffing as if the fiber bundle 100 were partially cut. In order to obtain 100, the pressing force is 0.04 to 2.0 N / mm, the tension is in the range of 0.02 to 0.2 N / mm, and the tension difference is in the range of 0.05 to 0.5 N / mm. is preferred.

An imaging means for detecting the presence or absence of twisting of the fiber bundle 100 is provided in a range of 10 to 1,000 mm apart from the separating means 200 thrust into the fiber bundle 100 in at least one of the front and rear directions along the longitudinal direction of the fiber bundle 100. is also preferred. By specifying the position of the twist in advance by this imaging, and by controlling the separating means 200 so as not to thrust into the twist, it is possible to prevent a mistake in thrusting. Further, when the twist approaches the inserted fiber separating means 200, the fiber bundle 100 can be prevented from narrowing by extracting the fiber separating means 200, that is, by not separating the twist. Here, the piercing error means that the fiber bundle 100 is pushed in the direction in which the separating means 200 is inserted into the twisting, and the fiber bundle 100 is only pushed in the direction in which the separating means 200 inserts, and the fiber bundle is not separated.

In a configuration in which a plurality of separating means 200 exist in the width direction of the fiber bundle 100 and are arranged at equal intervals, when the width of the fiber bundle 100 changes, the number of divided single yarns also changes, so stable It may not be possible to separate the number of single yarns. In addition, if the twist is forcibly separated, the fiber bundle 100 is cut at the single yarn level and a large amount of fluff is generated. If a large entangled accumulation portion 120 is left, it is likely to be caught by the fiber bundle 100 unwound from the roll.

When the twist of the fiber bundle 100 is detected, the traveling speed of the fiber bundle 100 may be changed instead of controlling the fiber separating means 200 not to plunge into the twist. Specifically, after the twist is detected, the running speed of the fiber bundle 100 is increased at the timing when the fiber separating means 200 is extracted from the fiber bundle 100 until the twist passes through the fiber separating means 200. Thus, twisting can be efficiently avoided.

Further, the apparatus may further include an image arithmetic processing means for calculating an image obtained by the imaging means, and may further comprise a pressing force control means for controlling the pressing force of the fiber sorting means 200 based on the computation result of the image arithmetic processing means. . For example, when the image arithmetic processing means detects the twist, the passability of the twist can be improved when the fiber separating means passes the twist. Specifically, it is preferable to detect the twist by the imaging means and control the fiber sorting means 200 so that the pressing force is reduced from immediately before the projecting portion 210 contacts the detected twist until it passes the detected twist. When twisting is detected, it is preferable to reduce the pressing force to within the range of 0.01 to 0.8 times the upper limit. If it falls below this range, the pressing force cannot be detected substantially, making it difficult to control the pressing force, and it becomes necessary to improve the detection accuracy of the control device itself. On the other hand, when the above range is exceeded, the frequency of separating the twists increases and the fiber bundle becomes thin.

In addition to simply inserting the fiber separating means 200 having the projecting portion 210 into the fiber bundle 100, it is also a preferred embodiment to use a rotatable rotating fiber separating means 220 as the fiber separating means. FIG. 5 is an explanatory diagram showing an example of a movement cycle for inserting the rotating fiber separating means. The rotating fiber separating means 220 has a rotating mechanism having a rotating shaft 240 orthogonal to the longitudinal direction of the fiber bundle 100, and the surface of the rotating shaft 240 is provided with a projection 210. As shown in FIG. As the fiber bundle 100 runs along the fiber bundle running direction b (arrow) in the figure, the projecting portion 210 provided on the rotating fiber separating means 220 is pushed into the fiber bundle 100, and the fiber separating process is started. . Here, although illustration is omitted, the rotary fiber separating means 220 preferably has a pressing force detection mechanism and a rotation stop position holding mechanism. Until a predetermined pressing force is applied to the rotating fiber separating means 220 by both mechanisms, the rotation stop position is held at the position shown in FIG. When a predetermined pressing force is exceeded, such as when an entangled portion 160 is generated in the projecting portion 210, the rotating fiber separating means 220 starts rotating as shown in FIG. 5(B). Thereafter, as shown in FIG. 5C, the projecting portion 210 (marked by a black circle) is removed from the fiber bundle 100 and the next projecting portion 210 (marked by a white circle) is pushed into the fiber bundle 100 . The shorter the operation in FIGS. 5A to 5C, the shorter the undivided section. It is preferable to shorten the operation of FIG. 5(C).

By arranging a large number of projecting portions 210 on the rotary separating means 220, it is possible to obtain the fiber bundle 100 with a high separation processing ratio and to extend the life of the rotary separating means 220. A fiber bundle with a high splitting treatment ratio is a fiber bundle in which the length of the splitting treatment is increased in the fiber bundle, or a fiber in which the frequency of occurrence of the splitting treatment and the unsplitting treatment is increased. It's about bundles. In addition, as the number of protrusions 210 provided in one rotating fiber separating means increases, the frequency of contact with the fiber bundle 100 and wear of the protrusions 210 can be reduced, thereby extending the service life. The number of protruding portions 210 to be provided is preferably 3 to 12, more preferably 4 to 8, arranged at equal intervals on the outer edge of the disk.

In this way, when it is attempted to obtain the fiber bundle 100 having a stable fiber bundle width while prioritizing the fiber separation processing rate and the life of the projecting portion, the rotating fiber separation means 220 is equipped with an imaging means for detecting twist. It is preferable to have Specifically, the rotating fiber separating means 220 intermittently repeats rotation and stopping until the image pickup means detects the twist to perform the fiber separating process. The width of the fiber bundle can be stabilized by increasing the rotation speed of the fiber means 220 and/or shortening the stop time. It is also possible to set the stop time to zero, that is, to keep rotating continuously without stopping.

In addition to the method of repeating intermittent rotation and stopping of the rotary separating means 220, the rotary separating means 220 may be continuously rotated. At that time, it is preferable to relatively speed up or slow down either one of the running speed of the fiber bundle 100 and the rotational speed of the rotary separating means 220 . When the speed is the same, the projecting portion 210 is pushed into/pulled out from the fiber bundle 100. Therefore, although the fiber separation section can be formed, the fiber separation action on the fiber bundle 100 is weak, so the fiber separation process is not performed. It may not be done enough. If one of the speeds is relatively too fast or too slow, the number of contact between the fiber bundle 100 and the protruding portion 210 increases, and there is a risk of thread breakage due to rubbing, resulting in poor continuous productivity. Sometimes.

The present invention may further include a reciprocating mechanism for performing the insertion and extraction of the separating means 200 and the rotary separating means 220 by reciprocating the separating means 200 and the rotary separating means 220 . It is also a preferred embodiment to further have a reciprocating mechanism for reciprocating the separating means 200 and the rotating separating means 220 along the feeding direction of the fiber bundle 100 . Linear motion actuators such as pneumatic or electric cylinders and sliders can be used for the reciprocating mechanism.

When reinforcing fibers are used in the fiber bundle, the number of fiber separation processing sections is at least (F/10,000-1) or more and less than (F/50-1) in a certain width direction area. It is preferred to have Here, F is the total number of single yarns constituting the fiber bundle to be subjected to the splitting process. The number of fiber separation treatment sections is such that at least (F/10,000-1) or more fiber separation treatment sections are provided in a certain width direction region, so that the fiber bundle is cut into a predetermined length and discontinuous fibers are obtained. When the reinforced composite material is formed, the ends of the reinforcing fiber bundles in the discontinuous fiber reinforced composite material are finely divided, so that a discontinuous fiber reinforced composite material having excellent mechanical properties can be obtained. In addition, when the split fiber bundle is used as continuous fibers without being cut, when impregnating with resin or the like in a post-process to make a reinforcing fiber composite material, from the region containing many fiber split treatment sections, It serves as a starting point for resin impregnation, thereby shortening the molding time and reducing voids and the like in the reinforcing fiber composite material. By setting the number of splitting treatment sections to less than (F/50-1) points, the resulting split fiber bundle is less likely to break, and a decrease in mechanical properties when used as a fiber-reinforced composite material can be suppressed.

If the fiber separation treatment section is provided with periodicity and regularity in the longitudinal direction of the fiber bundle 100, when the fiber bundle is cut into discontinuous fibers of a predetermined length in a subsequent step, The number of fiber bundles can be easily controlled.

Next, the timing of application of the sizing agent in the present invention will be described. FIG. 6 shows an example of the timing of the step of applying the sizing agent during the manufacturing process of the reinforcing fiber bundle in the manufacturing method of the reinforcing fiber bundle according to the present invention. FIG. 6 shows pattern A and pattern A in which the sizing agent application step 400 is performed before the fiber separation treatment step 300 during the step of forming the fiber bundle 180 through the fiber separation treatment step 300 of the fiber bundle 100 . , Pattern B, which is performed after the fiber separation process step 300, is shown. Either timing of pattern A or pattern B is possible.

FIG. 7 shows an example of the timing of the sizing agent application step 400 during the reinforcing fiber bundle manufacturing process in the reinforcing fiber bundle manufacturing method including the fiber bundle widening step 301 according to the present invention. In FIG. 7, in the process of forming the split fiber bundle 180 through the fiber bundle widening step 301 and the fiber splitting treatment step 300 in this order, the sizing agent applying step 400 is replaced by the fiber bundle widening step 301 . The pattern C performed before the fiber bundle widening process 301 and the fiber separation process 300, the pattern D performed after the fiber separation process 300, and the pattern E performed after the fiber separation process 300 are shown. Any timing of pattern C, pattern D, and pattern E is possible, but the timing of pattern D is most preferable from the viewpoint of achieving the optimum fiber separation treatment.

FIG. 8 shows the timing of the sizing agent applying step including the sizing agent application step and the drying step during the step of manufacturing the reinforcing fiber bundle in the method for producing the reinforcing fiber bundle constituting the fiber-reinforced thermoplastic resin molding material according to the present invention. shows an example. The sizing agent applying step 400 includes a sizing agent applying step 401 and a drying step 402. FIG. In the process of forming the split fiber bundle 180 through the treatment process 300, the pattern F performed before the split treatment process 300 and the pattern G performed after the split treatment process 300 are shown. there is Either pattern F or pattern G timing is possible. Pattern F is substantially the same as pattern A in FIG. 6, and pattern G is substantially the same as pattern B in FIG.

FIG. 9 shows the difference between the sizing agent application step and the sizing agent application step including the drying step in the manufacturing process of the reinforcing fiber bundle in the method for producing the reinforcing fiber bundle constituting the fiber-reinforced thermoplastic resin molding material according to the present invention. timing example. In pattern H in the timing example shown in FIG. 9, the sizing agent application step 401 and the drying step 402 in the sizing agent application step 400 are separated and performed at different timings. The sizing agent application step 401 is performed before the fiber separation treatment step 300 , and the drying step 402 is performed after the fiber separation treatment step 300 .

FIG. 10 shows an example of the timing of the sizing agent applying step including the sizing agent application step and the drying step in the method for manufacturing a reinforcing fiber bundle including the fiber bundle widening step according to the present invention. During the step of forming the split fiber bundle 180 through the step 301 and the splitting treatment step 300 in this order, the sizing agent application step 401 of the sizing agent application step is performed before the fiber bundle widening step 301, As for the drying process 402, pattern I performed between the fiber bundle widening process 301 and the fiber separation process 300 and pattern J performed after the fiber separation process 300 are shown.

FIG. 11 shows another timing example of the sizing agent applying step including the sizing agent application step and the drying step in the method for manufacturing a reinforcing fiber bundle including the fiber bundle widening step according to the present invention. In the process of forming the split fiber bundle 180 through the bundle widening step 301 and the fiber separating treatment step 300 in this order, the sizing agent application step 401 of the sizing agent applying step is performed by performing the fiber bundle widening step 301 and the fiber splitting treatment step. 300, and the drying step 402 is performed after the fiber separation treatment step 300. Pattern K is shown.

Thus, in the method for producing a reinforcing fiber bundle according to the present invention, it is possible to apply the sizing agent at various timings.

The average bundle width of the chopped reinforcing fiber bundles constituting the fiber-reinforced thermoplastic resin molding material of the present invention is preferably 0.03 mm or more, more preferably 0.05 mm or more, and still more preferably 0.07 mm or more. If it is less than 0.03 mm, there is a concern that the fluidity of the molding material may be poor. The average bundle width of the reinforcing fiber bundles constituting the fiber-reinforced thermoplastic resin molding material is preferably 3 mm or less, more preferably 2 mm or less, and even more preferably 1 mm or less. If it exceeds 3 mm, there is a concern that the mechanical properties of the molded product may deteriorate.

The upper limit of the average number of fibers in the chopped reinforcing fiber bundle used in the present invention is preferably 4,000 or less, more preferably 3,000 or less, and even more preferably 2,000 or less. Within this range, the mechanical properties of the molded article can be enhanced. The lower limit of the average number of fibers in the bundle is preferably 50 or more, more preferably 100 or more, and even more preferably 200 or more. Within this range, the fluidity of the molding material can be enhanced. A method for deriving the average number of fibers will be described later.

According to the present invention, the width of the chopped reinforcing fiber bundle after application of the sizing agent before being immersed in water is W3, and the reinforcing fiber bundle is immersed in water at 25 ° C. for 5 minutes, taken out, and drained for 1 minute. Assuming that the width of the reinforcing fiber bundle is W4, the width change rate W4/W3 of the reinforcing fiber bundle is preferably 0.6 or more, more preferably 0.7 or more, and still more preferably 0.8 or more. If the width change rate W4/W3 of the reinforcing fiber bundle is less than 0.6, the water-soluble physical properties of the sizing agent attached to the reinforcing fiber bundle may remain, causing the fiber bundle to reaggregate. Reaggregation makes it difficult to maintain the shape of the fiber bundle adjusted to the optimum number of single yarns. If it is not possible to maintain the form of a fiber bundle adjusted to the optimum number of single yarns, it is not possible to obtain an optimum form of the intermediate base material, and it is impossible to develop fluidity during molding and the mechanical properties of the molded product in a well-balanced manner. becomes difficult. Also, the width change rate W4/W3 is preferably 1.1 or less. If the width change rate W4/W3 exceeds 1.1, the fiber bundle lacks flexibility and becomes too hard, which may hinder smooth winding and unwinding of the bobbin. In addition, there is a possibility that single filament splitting occurs during cutting, and an ideal chopped fiber bundle shape cannot be obtained. A method for deriving the width change rate W4/W3 of the reinforcing fiber bundle will be described later.

In the present invention, the matrix thermoplastic resin impregnated into the bundle-like aggregate of chopped fiber bundles is not particularly limited, and examples thereof include polyamide resin, polyacetal, polyacrylate, polysulfone, ABS, polyester, acrylic, polybutylene terephthalate ( PBT), polyethylene terephthalate (PET), polyethylene, polypropylene, polyphenylene sulfide (PPS), polyether ether ketone (PEEK), liquid crystal polymer, vinyl chloride, fluororesins such as polytetrafluoroethylene, and silicone. In particular, it is preferable to use a polyamide-based resin as the thermoplastic resin, and it is preferable to blend an inorganic antioxidant with the polyamide. The thermoplastic polyamide resin used in the present invention includes, for example, nylon 6, nylon 11, and nylon 12 obtained by ring-opening polymerization of a cyclic lactam or polycondensation of ω-aminocarboxylic acid, and those obtained by polycondensation of diamine and dicarboxylic acid. Nylon 66, Nylon 610, Nylon 612, Nylon 6T, Nylon 6I, Nylon 9T, Nylon M5T, Nylon MFD6, Nylon 66.6.6I obtained by polycondensation of two or more diamines and dicarboxylic acids, Nylon 66.6. Copolymerized nylon such as 12 can be preferably used. In particular, nylon 6, 66, 610 is preferable from the viewpoint of mechanical properties and cost.

Copper halides or derivatives thereof used in the present invention include copper iodide, copper bromide, copper chloride, complex salts of mercaptobenzimidazole and copper iodide, and the like. Among them, copper iodide and a complex salt of mercaptobenzimidazole and copper iodide can be preferably used. The amount of copper halide or its derivative to be added is preferably in the range of 0.001 to 5 parts by weight with respect to 100 parts by weight of the thermoplastic polyamide resin. If the amount added is less than 0.001 part, resin decomposition, smoke and odor during preheating cannot be suppressed, and if the amount is 5 parts by weight or more, the improvement effect cannot be improved. Furthermore, 0.002 to 1 part by weight is preferable from the balance between the heat stabilization effect and the cost.

In the present invention, the method for impregnating the matrix resin into the bundle aggregate of chopped fiber bundles is not particularly limited. and the thermoplastic resin fibers contained in the bundle-like aggregate can be used as it is as a matrix resin, or a bundle-like aggregate that does not contain thermoplastic resin fibers can be used as a raw material to produce a fiber-reinforced thermoplastic resin molding material. may be impregnated with the matrix resin at any stage during the production of the

Moreover, even when a bundle-like assembly containing thermoplastic resin fibers is used as a raw material, it is possible to impregnate the matrix resin at any stage during the production of the fiber-reinforced thermoplastic resin molding material. In such a case, the resin constituting the thermoplastic resin fiber and the matrix resin may be the same resin or different resins. When the resin constituting the thermoplastic resin fiber and the matrix resin are different, it is preferable that the two have compatibility or a high affinity.

In the production of the fiber-reinforced thermoplastic resin molding material, impregnation of the thermoplastic resin, which is the matrix resin, into the bundle aggregate can be carried out using an impregnation press. The press machine is not particularly limited as long as it can achieve the temperature and pressure required for impregnation with the matrix resin, and a normal press machine having a flat platen that moves up and down, or a mechanism in which a pair of endless steel belts run. A so-called double belt press can be used. In the impregnation step, the matrix resin can be formed into a sheet such as a film, nonwoven fabric, or woven fabric, laminated with a discontinuous fiber mat, and in this state, the matrix resin can be melted and impregnated using the press machine or the like. Alternatively, a matrix resin in the form of particles may be dispersed on the bundle-like aggregate to form a laminate, or the chopped fiber bundle may be dispersed at the same time and mixed inside the bundle-like aggregate.

The volume content of the reinforcing fibers in the fiber-reinforced resin molding material is preferably 20% by volume or more, more preferably 25% by volume or more, and even more preferably 30% by volume or more. When the volume content of reinforcing fibers is less than 20% by volume, the mechanical properties of the fiber-reinforced resin molding material tend to deteriorate. On the other hand, the volume content of reinforcing fibers in the fiber-reinforced resin molding material is preferably 70% by volume or less, more preferably 65% by volume or less, and even more preferably 60% by volume or less. If the volume content of the reinforcing fibers exceeds 70% by volume, the mechanical properties of the fiber-reinforced resin molding material tend to improve, but the moldability tends to deteriorate.

Next, examples of the present invention and comparative examples will be described. It should be noted that the present invention is not limited at all by these examples and comparative examples.

(1) Raw material used/reinforced fiber bundle (1): Carbon fiber bundle (“PX35” manufactured by ZOLTEK, number of single yarns: 50,000, “13” (epoxy) sizing agent, amount of sizing agent adhered: 1.5% by weight) was used.
- Reinforcing fiber bundle (2): A carbon fiber bundle (“PX35” manufactured by ZOLTEK, 50,000 single yarns, no sizing agent) was used.
- Reinforcing fiber bundle (3): A glass fiber bundle (240TEX manufactured by Nitto Boseki, number of single yarns: 1,600) was used.
· Reinforcing fiber bundle (4): A carbon fiber bundle ("PX35" manufactured by ZOLTEK, 50,000 single yarns, no sizing agent) was used.
Resin sheet (1): A sheet having a basis weight of 150 g/m ² was produced using a polyamide masterbatch made of polyamide 6 resin (“Amilan” (registered trademark) CM1001, manufactured by Toray Industries, Inc.).
・ Resin sheet (2): 90% by mass of unmodified polypropylene resin (“Prime Polypro” (registered trademark) J106MG, manufactured by Prime Polymer Co., Ltd.) and acid-modified polypropylene resin (“ADMER”, manufactured by Mitsui Chemicals, Inc.) (Registered Trademark) QE800) A sheet was produced using a polypropylene masterbatch consisting of 10% by mass.
- Sizing agent (1): A water-soluble polyamide ("T-70" manufactured by Toray Industries, Inc.) was used.
- Sizing agent (2): A water-soluble polyamide (“A-90” manufactured by Toray Industries, Inc.) was used.
- Sizing agent (3): A water-soluble polyamide ("P-70" manufactured by Toray Industries, Inc.) was used.
- Sizing agent (4): A water-soluble polyamide ("P-95" manufactured by Toray Industries, Inc.) was used.

(2) Method for measuring adhesion amount of sizing agent or water-soluble polyamide About 5 g of carbon fiber bundles to which the sizing agent or water-soluble polyamide was adhered were sampled and put into a heat-resistant container. Next, this container is dried at 80° C. under vacuum conditions for 24 hours, cooled to room temperature while being careful not to absorb moisture, and the weight of the weighed carbon fiber is set to m1 (g), and then the container is placed in a nitrogen atmosphere. , and 450°C. The carbon fiber was cooled to room temperature while taking care not to absorb moisture, and the weight of the weighed carbon fiber was taken as m2 (g). After the above treatment, the adhesion amount of the sizing agent or water-soluble polyamide to the carbon fiber was determined by the following formula. Ten fiber bundles were measured, and the average value was calculated.
Adhesion amount (% by weight) = 100 × {(m1-m2) / m1}

(3) Measurement of drape value A reinforcing fiber bundle cut to 30 cm is stretched straight and placed on a flat table to confirm that it is neither curved nor twisted. If bending or twisting occurs, it is preferably removed by heating at 100° C. or less or applying pressure at 0.1 MPa or less. As shown in FIG. 12, in an atmosphere of 23±5° C., a reinforcing fiber bundle cut to 30 cm was fixed to the end of a rectangular parallelepiped stand, and at this time, the reinforcing fiber bundle was fixed so as to protrude from the end of the stand by 25 cm. . That is, a portion of 5 cm from the edge of the reinforcing fiber bundle was positioned at the edge of the table. After standing in this state for 5 minutes, the shortest distance between the end of the reinforcing fiber bundle that was not fixed to the table and the side surface of the table was measured and taken as the drape value D1. After the measured reinforcing fiber bundle was immersed in water at 25° C. for 5 minutes, it was taken out and the water was drained. Next, the reinforcing fiber bundle was dried at 80° C. under vacuum conditions for 24 hours, and after being completely dried, the drape value after dipping treatment was determined as D2 by the same method as described above. The number of measurements was set to n=5, and the average value was adopted.

(4) Measurement of hardness The hardness of the reinforcing fiber bundle was measured using a HANDLE-O-Meter (manufactured by Daiei Kagaku Seiki Seisakusho "CAN-1MCB") according to the JIS L-1096 E method (handle ometer method). . The reinforcing fiber bundle was opened and adjusted so that the length of the test piece used for hardness measurement was 10 cm, the number of filaments was 1,700 to 550, and the width was 1 mm. Moreover, the slit width was set to 20 mm. A reinforcing fiber bundle as a test piece was placed on the test table provided with the slit groove, and the resistance force (g) generated when the test piece was pushed into the groove to a predetermined depth (8 mm) with a blade was measured. . The hardness of the reinforcing fiber bundle was obtained from the average value of three measurements.

(5) Measurement of width change rate of reinforcing fiber bundle coated with sizing agent It was cut and clipped at a position of 30 mm from one end, and the width was measured at 5 points between 100 mm from the opposite end, and the average value was taken as W1 before immersion. Then, after immersing it in water at 25°C for 5 minutes, take it out, hang it with the clipped side facing up, drain the water for 1 minute, and then the width between the opposite end of the clip and 100 mm was measured at 5 points, and the average value was taken as W2 after immersion. Through the above processing, the width change rate of the resin-containing reinforcing fiber bundle was determined by the following equation.
Width change rate = W2/W1

(6) Measurement of width change rate of chopped fiber bundle The width of the chopped fiber bundle obtained by cutting the reinforcing fiber bundle was measured using a microscope, and was defined as W3 before immersion. After that, after immersing in water at 25 ° C. for 5 minutes, take it out with tweezers, carefully place it on Kimwipe so that the shape does not shift, drain the water for 1 minute, measure the width, and measure the width after immersion. W4. After the above processing, the width change rate of the chopped fiber bundle was determined by the following equation.
Width change rate = W4/W3

(7) Wf (weight content of reinforcing fiber in fiber-reinforced resin molding material)
About 2 g of a sample was cut out from the fiber-reinforced resin molding material, and its mass was measured. After that, the sample was heated in an electric furnace heated to 500° C. for 1 hour to burn off the organic matter such as the matrix resin. After cooling to room temperature, the mass of the remaining reinforcing fibers was measured. The weight ratio Wf (% by weight) of the reinforcing fiber was calculated by measuring the ratio of the mass of the sample before burning off the organic matter such as the matrix resin to the mass of the reinforcing fiber.

(8) Method for evaluating mechanical properties A fiber-reinforced resin molding material was molded by the method described below to obtain a flat plate molding of 500 x 400 mm. The longitudinal direction of the flat plate is set at 0°, and 16 test pieces of 100 × 25 × 2 mm are cut from the obtained flat plate from the 0° and 90° directions (total of 32 pieces). , the bending strength was determined. A bending strength of 350 MPa or more was evaluated as A, and a bending strength of less than 350 MPa was evaluated as B.

(9) Fluidity test (stamping molding)
Two sheets of fiber reinforced resin molding material with dimensions of 150 mm × 150 mm × 2 mm are stacked, and after preheating so that the temperature at the center of the base material (the temperature between the two sheets) is 260 ° C., the press platen heated to 150 ° C. and pressurized at 10 MPa for 30 seconds. The area A2 (mm ² ) after compression and the area A1 (mm ² ) of the fiber-reinforced resin molding material before pressing were measured, and A2/A1×100 was taken as the flow rate (%). A flow rate of 250% or more was rated as A, and a flow rate of less than 250% was rated as B.
・In the case of resin sheet 2 Two layers of fiber reinforced resin molding material with dimensions of 150 mm x 150 mm x 2 mm are stacked. It was placed on a heated press platen and pressed at 10 MPa for 30 seconds. The area A2 (mm ² ) after this compression and the area A1 (mm ² ) of the substrate before pressing were measured, and A2/A1×100 was taken as the flow rate (%). A flow rate of less than 200% was rated as C, 200% or more and less than 300% as B, and 300% or more as A.

(10) Process passability The process passability of separating the reinforcing fiber bundle and continuously cutting and scattering the separated reinforcing fiber bundle was evaluated as follows.
A: The reinforcing fiber bundle can be separated. The separated reinforcing fiber bundle can be unwound from the bobbin, cut and scattered without problems.
B: The reinforcing fiber bundle can be separated. However, the separated reinforcing fiber bundle winds around the bobbin or cutter part 1 to 7 times out of 10 times.
C: The reinforcing fiber bundle cannot be separated. Alternatively, split fibers can be formed, but the split reinforcing fiber bundle is wound around the bobbin or the cutter part eight times or more out of ten times.

(Example 1)
The reinforcing fiber bundle (1) is unwound at a constant speed of 10 m/min using a winder, passed through a vibrating widening roll that vibrates in the axial direction at 10 Hz, subjected to widening treatment, and then passed through a width regulating roll with a width of 50 mm. A reinforcing fiber bundle widened to 50 mm was obtained.

Next, the widened reinforcing fiber bundle is continuously immersed in a resin treatment liquid obtained by diluting a secondary sizing agent (sizing agent (1)) with purified water, and then hot rollers at 250°C and a drying oven at 250°C (atmospheric atmosphere) and heat-treated for 1.5 minutes. The sizing agent adhesion amount of the reinforcing fiber bundle was 0.1% by weight. It should be noted that this is the total deposition amount not including the primary sizing agent.

An iron plate for fiber separation treatment having a projecting shape of 0.2 mm in thickness, 3 mm in width, and 20 mm in height was placed on the obtained reinforcing fiber bundle at equal intervals of 1 mm in the width direction of the reinforcing fiber bundle. A set fiber separation treatment means was prepared. This fiber separating means was intermittently inserted into and removed from the reinforcing fiber bundle. At this time, the step of piercing the reinforcing fiber bundle traveling at a constant speed of 10 m/min with the separating means for 3 seconds, pulling out the separating means for 0.2 seconds, and piercing again was repeated. As shown in Table 1, the obtained fiber bundle width W3 was about 1 mm.

Subsequently, the obtained reinforcing fiber bundles are continuously put into a rotary cutter, cut at a fiber length of 25 mm and at a cutting angle of 20°, and scattered so as to be uniformly dispersed, resulting in a discontinuous fiber having an isotropic fiber orientation. A fibrous nonwoven fabric was obtained. The basis weight of the obtained discontinuous fiber nonwoven fabric was 250 g/m ² .

Next, 5 non-continuous fiber non-woven fabrics and 10 resin sheets (1) were prepared so that the weight ratio of the discontinuous-fiber non-woven fabric and the resin sheet (1) was 45:55. After laminating two sheets of nonwoven fabric between layers, the whole was sandwiched between stainless steel plates, preheated at 240° C. for 90 seconds, and hot-pressed at 240° C. for 180 seconds while applying a pressure of 2.0 MPa. Then, it was cooled to 50° C. under pressure to obtain a fiber-reinforced resin molding material having a thickness of 2 mm and a reinforcing fiber weight content of 46% by weight. Table 1 shows the results of the properties of the reinforcing fiber bundle, process passability, mechanical properties, and fluidity.

(Example 2)
Evaluation was performed in the same manner as in Example 1, except that the amount of sizing agent (1) applied was 2% by weight. Table 1 shows the results of the properties of the reinforcing fiber bundle, process passability, mechanical properties, and fluidity.

(Example 3)
The reinforcing fiber bundle (1) is unwound at a constant speed of 10 m/min using a winder, passed through a vibrating widening roll that vibrates in the axial direction at 10 Hz, subjected to widening treatment, and then passed through a width regulating roll of 30 mm width. A widened fiber bundle having a width of 30 mm was obtained.

Evaluation was performed in the same manner as in Example 2, except that the widening width was 30 mm. Table 1 shows the results of the properties of the reinforcing fiber bundle, process passability, mechanical properties, and fluidity.

(Example 4)
A reinforcing fiber bundle (1) is unwound at a constant speed of 10 m/min using a winder, passed through a vibrating widening roll that vibrates in the axial direction at 10 Hz, subjected to widening treatment, and then passed through a width regulating roll of 90 mm width. A widened fiber bundle having a width of 85 mm was obtained.

Evaluation was performed in the same manner as in Example 2, except that the widened width was 85 mm. Table 1 shows the results of the properties of the reinforcing fiber bundle, process passability, mechanical properties, and fluidity.

(Example 5)
Evaluation was performed in the same manner as in Example 2, except that the secondary sizing agent was heat treated at a temperature of 350° C. for 16 minutes. Table 1 shows the results of the properties of the reinforcing fiber bundle, process passability, mechanical properties, and fluidity.

(Example 6)
Evaluation was performed in the same manner as in Example 2 except that the sizing agent (1) of the secondary sizing agent was changed to the sizing agent (2). Table 1 shows the results of the properties of the reinforcing fiber bundle, process passability, mechanical properties, and fluidity.

(Example 7)
Evaluation was performed in the same manner as in Example 2 except that the sizing agent (1) of the secondary sizing agent was changed to the sizing agent (3). Table 1 shows the results of the properties of the reinforcing fiber bundle, process passability, mechanical properties, and fluidity.

(Example 8)
Evaluation was performed in the same manner as in Example 2 except that the sizing agent (1) of the secondary sizing agent was changed to the sizing agent (4). Table 1 shows the results of the properties of the reinforcing fiber bundle, process passability, mechanical properties, and fluidity.

(Comparative example 1)
Evaluation was performed in the same manner as in Example 1 except that the secondary sizing agent was not applied. Table 1 shows the results of the properties of the reinforcing fiber bundle, process passability, mechanical properties, and fluidity.

(Example 9)
Evaluation was performed in the same manner as in Example 2 except that the heat treatment temperature and time of the secondary sizing agent were set to 100° C. and 0.3 minutes. Table 1 shows the results of the properties of the reinforcing fiber bundle, process passability, mechanical properties, and fluidity.

(Comparative example 2)
Evaluation was performed in the same manner as in Example 2 except that the reinforcing fiber bundle (1) was changed to the reinforcing fiber bundle (2). Table 1 shows the results of the properties of the reinforcing fiber bundle, process passability, mechanical properties, and fluidity.

(Example 10)
The reinforcing fiber bundle (1) is unwound at a constant speed of 10 m/min using a winder, passed through a vibrating widening roll that vibrates in the axial direction at 10 Hz, subjected to widening treatment, and then passed through a width regulating roll to a width of 39 mm. A widened fiber bundle was obtained.

A mother liquor in which the sizing agent (1) is dissolved in water is prepared, and applied to the reinforcing fiber bundle (1) containing the epoxy sizing agent, which is a cross-linking agent, by an immersion method so as to have an adhesion amount of 4.1% by weight, Drying was performed with a hot roller at 250° C. for 0.5 minutes. As shown in Table 1, the number of fibers per unit width of the reinforcing fiber bundle (1) was 1,290/mm, the bundle thickness was 0.07 mm, the drape value was 135 mm, and the bundle hardness was 78 g.

An iron plate for fiber separation treatment having a protruding shape with a thickness of 0.2 mm, a width of 3 mm, and a height of 20 mm was placed on the obtained wide reinforcing fiber bundle (1) to which the sizing agent was applied, in the width direction of the reinforcing fiber bundle. A fiber separating means was set in parallel at regular intervals of 1 mm. This separating means was intermittently inserted into and removed from the widened fiber bundle to obtain a separated fiber bundle. At this time, the fiber separation processing means pierces the widened fiber bundle traveling at a constant speed of 10 m/min for 3 seconds to generate a fiber separation processing section, and pulls out the fiber separation processing means in 0.2 seconds. , and the piercing operation was repeated to obtain a reinforcing fiber bundle (1) having an average number of fibers in the bundle of 1,120 and an average bundle width of 0.6 mm.

Subsequently, the obtained reinforcing fiber bundle (1) is continuously inserted into a rotary cutter to cut the fiber bundle into 15 mm long fiber bundles, and the fibers are scattered so as to be uniformly dispersed, so that the fiber orientation is isotropic. A discontinuous fiber nonwoven was obtained. The fabric weight of the obtained discontinuous fiber nonwoven fabric was 0.25 kg/m ² . Next, after laminating so that the weight ratio of the discontinuous fiber nonwoven fabric and the resin sheet (1) is 45:55, the whole is sandwiched between stainless steel plates, preheated at 270° C. for 90 seconds, and then a pressure of 2.0 MPa is applied. It was hot-pressed at 240° C. for 180 seconds. Then, it was cooled to 50° C. under pressure to obtain a fiber-reinforced resin molding material having a thickness of 2 mm. At this time, the coating amount of the resin was adjusted at the stage of producing the resin sheet so that the weight content of the reinforcing fiber in the fiber-reinforced resin molding material was 46% by weight. The obtained fiber-reinforced resin molding material was evaluated for mechanical properties and fluidity test. Table 2 shows the results.

(Example 11 [Reference Example] )
The reinforcing fiber bundle (4) is unwound at a constant speed of 10 m/min using a winder, passed through a vibrating widening roll that vibrates in the axial direction at 10 Hz, subjected to widening treatment, and then passed through a width regulating roll to a width of 32 mm. A widened fiber bundle was obtained.

A mother liquor dissolved in water was adjusted so that the ratio of melamine, which is a cross-linking agent, to the additional sizing agent (1) was 0.22, and a reinforcing fiber bundle ( 4) and dried with a hot roller at 250° C. for 0.5 minutes. As shown in Table 1, the number of fibers per unit width of the reinforcing fiber bundle (4) was 1,540/mm, the bundle thickness was 0.08 mm, the drape value was 138 mm, and the bundle hardness was 81 g.

An iron plate for fiber separation treatment having a protruding shape with a thickness of 0.2 mm, a width of 3 mm and a height of 20 mm was placed on the obtained wide reinforcing fiber bundle (4) to which the sizing agent was applied in the width direction of the reinforcing fiber bundle. A fiber separating means was set in parallel at regular intervals of 1 mm. This separating means was intermittently inserted into and removed from the widened fiber bundle to obtain a separated fiber bundle. At this time, the fiber separation processing means pierces the widened fiber bundle traveling at a constant speed of 10 m/min for 3 seconds to generate a fiber separation processing section, and pulls out the fiber separation processing means in 0.2 seconds. , and the operation of stabbing again was repeated to separate the widened reinforcing fiber bundle (4) to obtain a reinforcing fiber bundle (4) having an average number of fibers in the bundle of 990 and an average bundle width of 0.6 mm.

Subsequently, the obtained reinforcing fiber bundle (4) is continuously inserted into a rotary cutter to cut the fiber bundle into fiber lengths of 15 mm, and the fibers are scattered so as to be uniformly dispersed, so that the fiber orientation is isotropic. A discontinuous fiber nonwoven was obtained. The fabric weight of the obtained discontinuous fiber nonwoven fabric was 0.25 kg/m ² . Next, after laminating so that the weight ratio of the discontinuous fiber nonwoven fabric and the resin sheet (2) is 45:55, the whole is sandwiched between stainless steel plates, preheated at 240° C. for 90 seconds, and then a pressure of 2.0 MPa is applied. It was hot-pressed at 210° C. for 180 seconds. Then, it was cooled to 50° C. under pressure to obtain a fiber-reinforced resin molding material having a thickness of 2 mm. At this time, the coating amount of the resin was adjusted at the stage of producing the resin sheet so that the weight content of the reinforcing fiber in the fiber-reinforced resin molding material was 46% by weight. The obtained fiber-reinforced resin molding material was evaluated for mechanical properties and fluidity test. Table 2 shows the results.

(Example 12 [Reference Example] )
The reinforcing fiber bundle (4) is unwound at a constant speed of 10 m/min using a winder, passed through a vibrating widening roll that vibrates in the axial direction at 10 Hz, subjected to widening treatment, and then passed through a width regulating roll to a width of 34 mm. A widened fiber bundle was obtained.

A mother liquor dissolved in water is adjusted so that the ratio of urea, which is a cross-linking agent, to the additional sizing agent (2) is 0.04, and the reinforcing fiber bundle ( 4) and dried with a hot roller at 250° C. for 0.5 minutes. As shown in Table 1, the number of fibers per unit width of the reinforcing fiber bundle (4) was 1,480/mm, the bundle thickness was 0.08 mm, the drape value was 142 mm, and the bundle hardness was 89 g.

An iron plate for fiber separation treatment having a protruding shape with a thickness of 0.2 mm, a width of 3 mm and a height of 20 mm was placed on the obtained wide reinforcing fiber bundle (4) to which the sizing agent was applied in the width direction of the reinforcing fiber bundle. A fiber separating means was set in parallel at regular intervals of 1 mm. This separating means was intermittently inserted into and removed from the widened fiber bundle to obtain a separated fiber bundle. At this time, the fiber separation processing means pierces the widened fiber bundle traveling at a constant speed of 10 m/min for 3 seconds to generate a fiber separation processing section, and pulls out the fiber separation processing means in 0.2 seconds. , and the operation of stabbing again was repeated to separate the widened reinforcing fiber bundle (4) to obtain a reinforcing fiber bundle (4) having an average number of fibers in the bundle of 1,030 and an average bundle width of 0.7 mm. .

Subsequently, the obtained reinforcing fiber bundle (4) is continuously inserted into a rotary cutter to cut the fiber bundle into fiber lengths of 15 mm, and the fibers are scattered so as to be uniformly dispersed, so that the fiber orientation is isotropic. A discontinuous fiber nonwoven was obtained. The fabric weight of the obtained discontinuous fiber nonwoven fabric was 0.25 kg/m ² . Next, after laminating so that the weight ratio of the discontinuous fiber nonwoven fabric and the resin sheet (1) is 45:55, the whole is sandwiched between stainless steel plates, preheated at 270° C. for 90 seconds, and then a pressure of 2.0 MPa is applied. It was hot-pressed at 240° C. for 180 seconds. Then, it was cooled to 50° C. under pressure to obtain a fiber-reinforced resin molding material having a thickness of 2 mm. At this time, the coating amount of the resin was adjusted at the stage of producing the resin sheet so that the weight content of the reinforcing fiber in the fiber-reinforced resin molding material was 46% by weight. The obtained fiber-reinforced resin molding material was evaluated for mechanical properties and fluidity test. Table 2 shows the results.

(Example 13 [Reference Example] )
The reinforcing fiber bundle (4) is unwound at a constant speed of 10 m/min using a winder, passed through a vibrating widening roll that vibrates in the axial direction at 10 Hz, subjected to widening treatment, and then passed through a width regulating roll to a width of 41 mm. A widened fiber bundle was obtained.

A mother liquor dissolved in water was adjusted so that the ratio of phenol, which is a cross-linking agent, to the additional sizing agent (2) was 0.38, and a reinforcing fiber bundle ( 4) and dried with a hot roller at 250° C. for 0.5 minutes. As shown in Table 1, the number of fibers per unit width of the reinforcing fiber bundle (4) was 1,220/mm, the bundle thickness was 0.07 mm, the drape value was 233 mm, and the bundle hardness was 195 g.

An iron plate for fiber separation treatment having a protruding shape with a thickness of 0.2 mm, a width of 3 mm and a height of 20 mm was placed on the obtained wide reinforcing fiber bundle (4) to which the sizing agent was applied in the width direction of the reinforcing fiber bundle. A fiber separating means was set in parallel at regular intervals of 1 mm. This separating means was intermittently inserted into and removed from the widened fiber bundle to obtain a separated fiber bundle. At this time, the fiber separation processing means pierces the widened fiber bundle traveling at a constant speed of 10 m/min for 3 seconds to generate a fiber separation processing section, and pulls out the fiber separation processing means in 0.2 seconds. , and the operation of stabbing again was repeated to split the widened reinforcing fiber bundle (4) to obtain a reinforcing fiber bundle (4) having an average number of fibers in the bundle of 1,880 and an average bundle width of 0.4 mm. .

Subsequently, the obtained reinforcing fiber bundle (4) is continuously inserted into a rotary cutter to cut the fiber bundle into fiber lengths of 15 mm, and the fibers are scattered so as to be uniformly dispersed, so that the fiber orientation is isotropic. A discontinuous fiber nonwoven was obtained. The fabric weight of the obtained discontinuous fiber nonwoven fabric was 0.25 kg/m ² . Next, after laminating so that the weight ratio of the discontinuous fiber nonwoven fabric and the resin sheet (1) is 45:55, the whole is sandwiched between stainless steel plates, preheated at 270° C. for 90 seconds, and then a pressure of 2.0 MPa is applied. It was hot-pressed at 240° C. for 180 seconds. Then, it was cooled to 50° C. under pressure to obtain a fiber-reinforced resin molding material having a thickness of 2 mm. At this time, the coating amount of the resin was adjusted at the stage of producing the resin sheet so that the weight content of the reinforcing fiber in the fiber-reinforced resin molding material was 46% by weight. The obtained fiber-reinforced resin molding material was evaluated for mechanical properties and fluidity test. Table 2 shows the results.

(Example 14 [Reference Example] )
The reinforcing fiber bundle (4) is unwound at a constant speed of 10 m/min using a winder, passed through a vibrating widening roll that vibrates in the axial direction at 10 Hz, subjected to widening treatment, and then passed through a width regulating roll to a width of 37 mm. A widened fiber bundle was obtained.

A mother liquor dissolved in water is adjusted so that the ratio of urea, which is a cross-linking agent, to the additional sizing agent (2) is 0.04, and the reinforcing fiber bundle ( 4) and dried with a hot roller at 250° C. for 0.5 minutes. As shown in Table 1, the number of fibers per unit width of the reinforcing fiber bundle (4) was 1,350/mm, the bundle thickness was 0.07 mm, the drape value was 133 mm, and the bundle hardness was 78 g.

An iron plate for fiber separation treatment having a protruding shape with a thickness of 0.2 mm, a width of 3 mm and a height of 20 mm was placed on the obtained wide reinforcing fiber bundle (4) to which the sizing agent was applied in the width direction of the reinforcing fiber bundle. A fiber separating means was set in parallel at regular intervals of 1 mm. This separating means was intermittently inserted into and removed from the widened fiber bundle to obtain a separated fiber bundle. At this time, the fiber separation processing means pierces the widened fiber bundle traveling at a constant speed of 10 m/min for 3 seconds to generate a fiber separation processing section, and pulls out the fiber separation processing means in 0.2 seconds. , and the operation of stabbing again was repeated to separate the widened reinforcing fiber bundle (4) to obtain a reinforcing fiber bundle (4) having an average number of fibers in the bundle of 5,230 and an average bundle width of 3.4 mm. .

Subsequently, the obtained reinforcing fiber bundle (4) is continuously inserted into a rotary cutter to cut the fiber bundle into fiber lengths of 15 mm, and the fibers are scattered so as to be uniformly dispersed, so that the fiber orientation is isotropic. A discontinuous fiber nonwoven was obtained. The fabric weight of the obtained discontinuous fiber nonwoven fabric was 0.25 kg/m ² . Next, after laminating so that the weight ratio of the discontinuous fiber nonwoven fabric and the resin sheet (1) is 45:55, the whole is sandwiched between stainless steel plates, preheated at 270° C. for 90 seconds, and then a pressure of 2.0 MPa is applied. It was hot-pressed at 240° C. for 180 seconds. Then, it was cooled to 50° C. under pressure to obtain a fiber-reinforced resin molding material having a thickness of 2 mm. At this time, the coating amount of the resin was adjusted at the stage of producing the resin sheet so that the weight content of the reinforcing fiber in the fiber-reinforced resin molding material was 46% by weight. The obtained fiber-reinforced resin molding material was evaluated for mechanical properties and fluidity test. Table 2 shows the results.

(Example 15 [Reference Example] )
The reinforcing fiber bundle (3) is unwound at a constant speed of 10 m/min using a winder, passed through a vibrating widening roll that vibrates in the axial direction at 10 Hz, subjected to widening treatment, and then passed through a width regulating roll to a width of 3 mm. A widened fiber bundle was obtained.

A mother liquor dissolved in water was adjusted so that the ratio of the cross-linking agent melamine and the additional sizing agent (2) was 0.22, and the reinforcing fiber bundle ( 3) and dried with a hot roller at 250° C. for 0.5 minutes. As shown in Table 1, the number of fibers per unit width of the reinforcing fiber bundle (3) was 550/mm, the bundle thickness was 0.07 mm, the drape value was 127 mm, and the bundle hardness was 76 g.

An iron plate for fiber separation treatment having a protruding shape with a thickness of 0.2 mm, a width of 3 mm and a height of 20 mm was placed on the obtained wide reinforcing fiber bundle (3) to which the sizing agent was applied in the width direction of the reinforcing fiber bundle. A fiber separating means was set in parallel at regular intervals of 1 mm. This separating means was intermittently inserted into and removed from the widened fiber bundle to obtain a separated fiber bundle. At this time, the fiber separation processing means pierces the widened fiber bundle traveling at a constant speed of 10 m/min for 3 seconds to generate a fiber separation processing section, and pulls out the fiber separation processing means in 0.2 seconds. , and the operation of stabbing again was repeated to separate the widened reinforcing fiber bundle (3) to obtain a reinforcing fiber bundle (3) having an average number of fibers in the bundle of 410 and an average bundle width of 0.7 mm.

Subsequently, the obtained reinforcing fiber bundle (3) is continuously inserted into a rotary cutter to cut the fiber bundle into 15 mm fiber lengths, and the fiber bundle is dispersed so as to be uniformly dispersed, so that the fiber orientation is isotropic. A discontinuous fiber nonwoven was obtained. The fabric weight of the obtained discontinuous fiber nonwoven fabric was 0.25 kg/m ² . Next, after laminating so that the weight ratio of the discontinuous fiber nonwoven fabric and the resin sheet (2) is 45:55, the whole is sandwiched between stainless steel plates, preheated at 240° C. for 90 seconds, and then a pressure of 2.0 MPa is applied. It was hot-pressed at 210° C. for 180 seconds. Then, it was cooled to 50° C. under pressure to obtain a fiber-reinforced resin molding material having a thickness of 2 mm. At this time, the coating amount of the resin was adjusted at the stage of producing the resin sheet so that the weight content of the reinforcing fiber in the fiber-reinforced resin molding material was 46% by weight. The obtained fiber-reinforced resin molding material was evaluated for mechanical properties and fluidity test. Table 2 shows the results.

(Example 16 [Reference Example] )
The reinforcing fiber bundle (4) is unwound at a constant speed of 10 m/min using a winder, passed through a vibrating widening roll that vibrates in the axial direction at 10 Hz, subjected to widening treatment, and then passed through a width regulating roll to a width of 34 mm. A widened fiber bundle was obtained.

A mother liquor dissolved in water is adjusted so that the ratio of urea, which is a cross-linking agent, to the additional sizing agent (3) is 0.22, and the reinforcing fiber bundle ( 4) and dried with a hot roller at 250° C. for 0.5 minutes. As shown in Table 1, the number of fibers per unit width of the reinforcing fiber bundle (4) was 1,480/mm, the bundle thickness was 0.08 mm, the drape value was 180 mm, and the bundle hardness was 123 g.

An iron plate for fiber separation treatment having a protruding shape with a thickness of 0.2 mm, a width of 3 mm and a height of 20 mm was placed on the obtained wide reinforcing fiber bundle (4) to which the sizing agent was applied in the width direction of the reinforcing fiber bundle. A fiber separating means was set in parallel at regular intervals of 1 mm. This separating means was intermittently inserted into and removed from the widened fiber bundle to obtain a separated fiber bundle. At this time, the fiber separation processing means pierces the widened fiber bundle traveling at a constant speed of 10 m/min for 3 seconds to generate a fiber separation processing section, and pulls out the fiber separation processing means in 0.2 seconds. , and the operation of stabbing again was repeated to separate the widened reinforcing fiber bundle (4) to obtain a reinforcing fiber bundle (4) having an average number of fibers in the bundle of 930 and an average bundle width of 0.6 mm.

Subsequently, the obtained reinforcing fiber bundle (4) is continuously inserted into a rotary cutter to cut the fiber bundle into fiber lengths of 15 mm, and the fibers are scattered so as to be uniformly dispersed, so that the fiber orientation is isotropic. A discontinuous fiber nonwoven was obtained. The fabric weight of the obtained discontinuous fiber nonwoven fabric was 0.25 kg/m ² . Next, after laminating so that the weight ratio of the discontinuous fiber nonwoven fabric and the resin sheet (1) is 45:55, the whole is sandwiched between stainless steel plates, preheated at 270° C. for 90 seconds, and then a pressure of 2.0 MPa is applied. It was hot-pressed at 240° C. for 180 seconds. Then, it was cooled to 50° C. under pressure to obtain a fiber-reinforced resin molding material having a thickness of 2 mm. At this time, the coating amount of the resin was adjusted at the stage of producing the resin sheet so that the weight content of the reinforcing fiber in the fiber-reinforced resin molding material was 46% by weight. The obtained fiber-reinforced resin molding material was evaluated for mechanical properties and fluidity test. Table 2 shows the results.

(Example 17 [Reference Example] )
The reinforcing fiber bundle (4) is unwound at a constant speed of 10 m/min using a winder, passed through a vibrating widening roll that vibrates in the axial direction at 10 Hz, subjected to widening treatment, and then passed through a width regulating roll to a width of 28 mm. A widened fiber bundle was obtained.

A mother liquor dissolved in water was adjusted so that the ratio of melamine, which is a cross-linking agent, to the additional sizing agent (3) was 0.22, and a reinforcing fiber bundle ( 4) and dried with a hot roller at 250° C. for 0.5 minutes. As shown in Table 1, the number of fibers per unit width of the reinforcing fiber bundle (4) was 1,780/mm, the bundle thickness was 0.1 mm, the drape value was 204 mm, and the bundle hardness was 163 g.

An iron plate for fiber separation treatment having a protruding shape with a thickness of 0.2 mm, a width of 3 mm and a height of 20 mm was placed on the obtained wide reinforcing fiber bundle (4) to which the sizing agent was applied in the width direction of the reinforcing fiber bundle. A fiber separating means was set in parallel at regular intervals of 1 mm. This separating means was intermittently inserted into and removed from the widened fiber bundle to obtain a separated fiber bundle. At this time, the fiber separation processing means pierces the widened fiber bundle traveling at a constant speed of 10 m/min for 3 seconds to generate a fiber separation processing section, and pulls out the fiber separation processing means in 0.2 seconds. , and the operation of stabbing again was repeated to split the widened reinforcing fiber bundle (4) to obtain a reinforcing fiber bundle (4) having an average number of fibers in the bundle of 1,540 and an average bundle width of 0.6 mm. .

Subsequently, the obtained reinforcing fiber bundle (4) is continuously inserted into a rotary cutter to cut the fiber bundle into fiber lengths of 15 mm, and the fibers are scattered so as to be uniformly dispersed, so that the fiber orientation is isotropic. A discontinuous fiber nonwoven was obtained. The fabric weight of the obtained discontinuous fiber nonwoven fabric was 0.25 kg/m ² . Next, after laminating so that the weight ratio of the discontinuous fiber nonwoven fabric and the resin sheet (1) is 45:55, the whole is sandwiched between stainless steel plates, preheated at 270° C. for 90 seconds, and then a pressure of 2.0 MPa is applied. It was hot-pressed at 240° C. for 180 seconds. Then, it was cooled to 50° C. under pressure to obtain a fiber-reinforced resin molding material having a thickness of 2 mm. At this time, the coating amount of the resin was adjusted at the stage of producing the resin sheet so that the weight content of the reinforcing fiber in the fiber-reinforced resin molding material was 46% by weight. The obtained fiber-reinforced resin molding material was evaluated for mechanical properties and fluidity test. Table 2 shows the results.

(Example 18 [Reference Example] )
The reinforcing fiber bundle (4) is unwound at a constant speed of 10 m/min using a winder, passed through a vibrating widening roll that vibrates in the axial direction at 10 Hz, subjected to widening treatment, and then passed through a width regulating roll to a width of 13 mm. A widened fiber bundle was obtained.

A mother liquor dissolved in water was adjusted so that the ratio of urea, which is a cross-linking agent, to the additional sizing agent (4) was 0.22, and the reinforcing fiber bundle ( 4) and dried with a hot roller at 250° C. for 0.5 minutes. As shown in Table 1, the number of fibers per unit width of the reinforcing fiber bundle (4) was 3,940/mm, the bundle thickness was 0.21 mm, the drape value was 243 mm, and the bundle hardness was 220 g.

An iron plate for fiber separation treatment having a protruding shape with a thickness of 0.2 mm, a width of 3 mm and a height of 20 mm was placed on the obtained wide reinforcing fiber bundle (4) to which the sizing agent was applied in the width direction of the reinforcing fiber bundle. A fiber separating means was set in parallel at regular intervals of 1 mm. This separating means was intermittently inserted into and removed from the widened fiber bundle to obtain a separated fiber bundle. At this time, the fiber separation processing means pierces the widened fiber bundle traveling at a constant speed of 10 m/min for 3 seconds to generate a fiber separation processing section, and pulls out the fiber separation processing means in 0.2 seconds. , and the operation of stabbing again was repeated to separate the widened reinforcing fiber bundle (4) to obtain a reinforcing fiber bundle (4) having an average number of fibers in the bundle of 1,120 and an average bundle width of 0.3 mm. .

Subsequently, the obtained reinforcing fiber bundle (4) is continuously inserted into a rotary cutter to cut the fiber bundle into fiber lengths of 15 mm, and the fibers are scattered so as to be uniformly dispersed, so that the fiber orientation is isotropic. A discontinuous fiber nonwoven was obtained. The fabric weight of the obtained discontinuous fiber nonwoven fabric was 0.25 kg/m ² . Next, after laminating so that the weight ratio of the discontinuous fiber nonwoven fabric and the resin sheet (2) is 45:55, the whole is sandwiched between stainless steel plates, preheated at 240° C. for 90 seconds, and then a pressure of 2.0 MPa is applied. It was hot-pressed at 210° C. for 180 seconds. Then, it was cooled to 50° C. under pressure to obtain a fiber-reinforced resin molding material having a thickness of 2 mm. At this time, the coating amount of the resin was adjusted at the stage of producing the resin sheet so that the weight content of the reinforcing fiber in the fiber-reinforced resin molding material was 46% by weight. The obtained fiber-reinforced resin molding material was evaluated for mechanical properties and fluidity test. Table 2 shows the results.

(Example 19 [Reference Example] )
The reinforcing fiber bundle (4) is unwound at a constant speed of 10 m/min using a winder, passed through a vibrating widening roll that vibrates in the axial direction at 10 Hz, subjected to widening treatment, and then passed through a width regulating roll to a width of 11 mm. A widened fiber bundle was obtained.

A mother liquor dissolved in water was adjusted so that the ratio of the cross-linking agent melamine and the additional sizing agent (4) was 0.22, and the reinforcing fiber bundle ( 4) and dried with a hot roller at 250° C. for 0.5 minutes. As shown in Table 1, the number of fibers per unit width of the reinforcing fiber bundle (4) was 4,380/mm, the bundle thickness was 0.24 mm, the drape value was 145 mm, and the bundle hardness was 84 g.

An iron plate for fiber separation treatment having a protruding shape with a thickness of 0.2 mm, a width of 3 mm and a height of 20 mm was placed on the obtained wide reinforcing fiber bundle (4) to which the sizing agent was applied in the width direction of the reinforcing fiber bundle. A fiber separating means was set in parallel at regular intervals of 1 mm. This separating means was intermittently inserted into and removed from the widened fiber bundle to obtain a separated fiber bundle. At this time, the fiber separation processing means pierces the widened fiber bundle traveling at a constant speed of 10 m/min for 3 seconds to generate a fiber separation processing section, and pulls out the fiber separation processing means in 0.2 seconds. , and the operation of stabbing again was repeated to separate the widened reinforcing fiber bundle (4) to obtain a reinforcing fiber bundle (4) having an average number of fibers in the bundle of 930 and an average bundle width of 0.6 mm.

Subsequently, the obtained reinforcing fiber bundle (4) is continuously inserted into a rotary cutter to cut the fiber bundle into fiber lengths of 15 mm, and the fibers are scattered so as to be uniformly dispersed, so that the fiber orientation is isotropic. A discontinuous fiber nonwoven was obtained. The fabric weight of the obtained discontinuous fiber nonwoven fabric was 0.25 kg/m ² . Next, after laminating so that the weight ratio of the discontinuous fiber nonwoven fabric and the resin sheet (1) is 45:55, the whole is sandwiched between stainless steel plates, preheated at 270° C. for 90 seconds, and then a pressure of 2.0 MPa is applied. It was hot-pressed at 240° C. for 180 seconds. Then, it was cooled to 50° C. under pressure to obtain a fiber-reinforced resin molding material having a thickness of 2 mm. At this time, the coating amount of the resin was adjusted at the stage of producing the resin sheet so that the weight content of the reinforcing fiber in the fiber-reinforced resin molding material was 46% by weight. The obtained fiber-reinforced resin molding material was evaluated for mechanical properties and fluidity test. Table 2 shows the results.

(Example 20 [Reference Example] )
The reinforcing fiber bundle (4) is unwound at a constant speed of 10 m/min using a winder, passed through a vibrating widening roll that vibrates in the axial direction at 10 Hz, subjected to widening treatment, and then passed through a width regulating roll to a width of 36 mm. A widened fiber bundle was obtained.

A mother liquor dissolved in water is adjusted so that the ratio of urea, which is a cross-linking agent, to the additional sizing agent (4) is 0.22, and the reinforcing fiber bundle ( 4) and dried with a hot roller at 350° C. for 11 minutes. As shown in Table 1, the number of fibers per unit width of the reinforcing fiber bundle (4) was 1,380/mm, the bundle thickness was 0.07 mm, the drape value was 136 mm, and the bundle hardness was 80 g.

An iron plate for fiber separation treatment having a protruding shape with a thickness of 0.2 mm, a width of 3 mm and a height of 20 mm was placed on the obtained wide reinforcing fiber bundle (4) to which the sizing agent was applied in the width direction of the reinforcing fiber bundle. A fiber separating means was set in parallel at regular intervals of 1 mm. This separating means was intermittently inserted into and removed from the widened fiber bundle to obtain a separated fiber bundle. At this time, the fiber separation processing means pierces the widened fiber bundle traveling at a constant speed of 10 m/min for 3 seconds to generate a fiber separation processing section, and pulls out the fiber separation processing means in 0.2 seconds. , and the operation of stabbing again was repeated to split the widened reinforcing fiber bundle (4) to obtain a reinforcing fiber bundle (4) having an average number of fibers in the bundle of 2,330 and an average bundle width of 0.7 mm. .

Subsequently, the obtained reinforcing fiber bundle (4) is continuously inserted into a rotary cutter to cut the fiber bundle into fiber lengths of 15 mm, and the fibers are scattered so as to be uniformly dispersed, so that the fiber orientation is isotropic. A discontinuous fiber nonwoven was obtained. The fabric weight of the obtained discontinuous fiber nonwoven fabric was 0.25 kg/m ² . Next, after laminating so that the weight ratio of the discontinuous fiber nonwoven fabric and the resin sheet (1) is 45:55, the whole is sandwiched between stainless steel plates, preheated at 270° C. for 90 seconds, and then a pressure of 2.0 MPa is applied. It was hot-pressed at 240° C. for 180 seconds. Then, it was cooled to 50° C. under pressure to obtain a fiber-reinforced resin molding material having a thickness of 2 mm. At this time, the coating amount of the resin was adjusted at the stage of producing the resin sheet so that the weight content of the reinforcing fiber in the fiber-reinforced resin molding material was 46% by weight. The obtained fiber-reinforced resin molding material was evaluated for mechanical properties and fluidity test. Table 2 shows the results.

(Example 21 [Reference Example] )
The reinforcing fiber bundle (4) is unwound at a constant speed of 10 m/min using a winder, passed through a vibrating widening roll that vibrates in the axial direction at 10 Hz, subjected to widening treatment, and then passed through a width regulating roll to a width of 33 mm. A widened fiber bundle was obtained.

A mother liquor dissolved in water is adjusted so that the ratio of urea, which is a cross-linking agent, to the additional sizing agent (4) is 0.22, and the reinforcing fiber bundle ( 4) and dried with a hot roller at 250° C. for 0.2 minutes. As shown in Table 1, the number of fibers per unit width of the reinforcing fiber bundle (4) was 1,520/mm, the bundle thickness was 0.08 mm, the drape value was 54 mm, and the bundle hardness was 28 g.

An iron plate for fiber separation treatment having a protruding shape with a thickness of 0.2 mm, a width of 3 mm and a height of 20 mm was placed on the obtained wide reinforcing fiber bundle (4) to which the sizing agent was applied in the width direction of the reinforcing fiber bundle. A fiber separating means was set in parallel at regular intervals of 1 mm. This separating means was intermittently inserted into and removed from the widened fiber bundle to obtain a separated fiber bundle. At this time, the fiber separation processing means pierces the widened fiber bundle traveling at a constant speed of 10 m/min for 3 seconds to generate a fiber separation processing section, and pulls out the fiber separation processing means in 0.2 seconds. , and the operation of stabbing again was repeated to separate the widened reinforcing fiber bundle (4) to obtain a reinforcing fiber bundle (4) having an average number of fibers in the bundle of 2,110 and an average bundle width of 0.6 mm. .

Subsequently, the obtained reinforcing fiber bundle (4) is continuously inserted into a rotary cutter to cut the fiber bundle into fiber lengths of 15 mm, and the fibers are scattered so as to be uniformly dispersed, so that the fiber orientation is isotropic. A discontinuous fiber nonwoven was obtained. The fabric weight of the obtained discontinuous fiber nonwoven fabric was 0.25 kg/m ² . Next, after laminating so that the weight ratio of the discontinuous fiber nonwoven fabric and the resin sheet (1) is 45:55, the whole is sandwiched between stainless steel plates, preheated at 270° C. for 90 seconds, and then a pressure of 2.0 MPa is applied. It was hot-pressed at 240° C. for 180 seconds. Then, it was cooled to 50° C. under pressure to obtain a fiber-reinforced resin molding material having a thickness of 2 mm. At this time, the coating amount of the resin was adjusted at the stage of producing the resin sheet so that the weight content of the reinforcing fiber in the fiber-reinforced resin molding material was 46% by weight. The obtained fiber-reinforced resin molding material was evaluated for mechanical properties and fluidity test. Table 2 shows the results.

(Example 22 [Reference Example] )
The reinforcing fiber bundle (4) is unwound at a constant speed of 10 m/min using a winder, passed through a vibrating widening roll that vibrates in the axial direction at 10 Hz, subjected to widening treatment, and then passed through a width regulating roll to a width of 33 mm. A widened fiber bundle was obtained.

A mother liquor dissolved in water was adjusted so that the ratio of melamine, which is a cross-linking agent, to the additional sizing agent (2) was 0.01, and a reinforcing fiber bundle ( 4) and dried with a hot roller at 250° C. for 0.2 minutes. As shown in Table 1, the number of fibers per unit width of the reinforcing fiber bundle (4) was 1,510/mm, the bundle thickness was 0.08 mm, the drape value was 46 mm, and the bundle hardness was 21 g.

An iron plate for fiber separation treatment having a protruding shape with a thickness of 0.2 mm, a width of 3 mm and a height of 20 mm was placed on the obtained wide reinforcing fiber bundle (4) to which the sizing agent was applied in the width direction of the reinforcing fiber bundle. A fiber separating means was set in parallel at regular intervals of 1 mm. This separating means was intermittently inserted into and removed from the widened fiber bundle to obtain a separated fiber bundle. At this time, the fiber separation processing means pierces the widened fiber bundle traveling at a constant speed of 10 m/min for 3 seconds to generate a fiber separation processing section, and pulls out the fiber separation processing means in 0.2 seconds. , and the operation of stabbing again was repeated to separate the widened reinforcing fiber bundle (4) to obtain a reinforcing fiber bundle (4) having an average number of fibers in the bundle of 1,140 and an average bundle width of 0.7 mm. .

Subsequently, the obtained reinforcing fiber bundle (4) is continuously inserted into a rotary cutter to cut the fiber bundle into fiber lengths of 15 mm, and the fibers are scattered so as to be uniformly dispersed, so that the fiber orientation is isotropic. A discontinuous fiber nonwoven was obtained. The fabric weight of the obtained discontinuous fiber nonwoven fabric was 0.25 kg/m ² . Next, after laminating so that the weight ratio of the discontinuous fiber nonwoven fabric and the resin sheet (1) is 45:55, the whole is sandwiched between stainless steel plates, preheated at 270° C. for 90 seconds, and then a pressure of 2.0 MPa is applied. It was hot-pressed at 240° C. for 180 seconds. Then, it was cooled to 50° C. under pressure to obtain a fiber-reinforced resin molding material having a thickness of 2 mm. At this time, the coating amount of the resin was adjusted at the stage of producing the resin sheet so that the weight content of the reinforcing fiber in the fiber-reinforced resin molding material was 46% by weight. The obtained fiber-reinforced resin molding material was evaluated for mechanical properties and fluidity test. Table 2 shows the results.

(Example 23 [Reference Example] )
The reinforcing fiber bundle (4) is unwound at a constant speed of 10 m/min using a winder, passed through a vibrating widening roll that vibrates in the axial direction at 10 Hz, subjected to widening treatment, and then passed through a width regulating roll to a width of 15 mm. A widened fiber bundle was obtained.

A mother liquor dissolved in water was adjusted so that the ratio of the cross-linking agent melamine and the additional sizing agent (2) was 0.04, and the reinforcing fiber bundle ( 4) and dried with a hot roller at 250° C. for 0.2 minutes. As shown in Table 1, the number of fibers per unit width of the reinforcing fiber bundle (4) was 1,440/mm, the bundle thickness was 0.08 mm, the drape value was 35 mm, and the bundle hardness was 24 g.

An iron plate for fiber separation treatment having a protruding shape with a thickness of 0.2 mm, a width of 3 mm and a height of 20 mm was placed on the obtained wide reinforcing fiber bundle (4) to which the sizing agent was applied in the width direction of the reinforcing fiber bundle. A fiber separating means was set in parallel at regular intervals of 1 mm. This separating means was intermittently inserted into and removed from the widened fiber bundle to obtain a separated fiber bundle. At this time, the fiber separation processing means pierces the widened fiber bundle traveling at a constant speed of 10 m/min for 3 seconds to generate a fiber separation processing section, and pulls out the fiber separation processing means in 0.2 seconds. , and the operation of stabbing again was repeated to separate the widened reinforcing fiber bundle (4) to obtain a reinforcing fiber bundle (4) having an average number of fibers in the bundle of 1,280 and an average bundle width of 0.7 mm. .

Subsequently, the obtained reinforcing fiber bundle (4) is continuously inserted into a rotary cutter to cut the fiber bundle into fiber lengths of 15 mm, and the fibers are scattered so as to be uniformly dispersed, so that the fiber orientation is isotropic. A discontinuous fiber nonwoven was obtained. The fabric weight of the obtained discontinuous fiber nonwoven fabric was 0.25 kg/m ² . Next, after laminating so that the weight ratio of the discontinuous fiber nonwoven fabric and the resin sheet (1) is 45:55, the whole is sandwiched between stainless steel plates, preheated at 270° C. for 90 seconds, and then a pressure of 2.0 MPa is applied. It was hot-pressed at 240° C. for 180 seconds. Then, it was cooled to 50° C. under pressure to obtain a fiber-reinforced resin molding material having a thickness of 2 mm. At this time, the coating amount of the resin was adjusted at the stage of producing the resin sheet so that the weight content of the reinforcing fiber in the fiber-reinforced resin molding material was 46% by weight. The obtained fiber-reinforced resin molding material was evaluated for mechanical properties and fluidity test. Table 2 shows the results.

(Example 24 [Reference Example] )
The reinforcing fiber bundle (4) is unwound at a constant speed of 10 m/min using a winder, passed through a vibrating widening roll that vibrates in the axial direction at 10 Hz, subjected to widening treatment, and then passed through a width regulating roll to a width of 34 mm. A widened fiber bundle was obtained.

A mother liquor dissolved in water was adjusted so that the ratio of phenol, which is a cross-linking agent, to the additional sizing agent (2) was 0.04, and a reinforcing fiber bundle ( 4) and dried with a hot roller at 250° C. for 0.2 minutes. As shown in Table 1, the number of fibers per unit width of the reinforcing fiber bundle (4) was 1,450/mm, the bundle thickness was 0.08 mm, the drape value was 131 mm, and the bundle hardness was 73 g.

An iron plate for fiber separation treatment having a protruding shape with a thickness of 0.2 mm, a width of 3 mm and a height of 20 mm was placed on the obtained wide reinforcing fiber bundle (4) to which the sizing agent was applied in the width direction of the reinforcing fiber bundle. A fiber separating means was set in parallel at regular intervals of 1 mm. This separating means was intermittently inserted into and removed from the widened fiber bundle to obtain a separated fiber bundle. At this time, the fiber separation processing means pierces the widened fiber bundle traveling at a constant speed of 10 m/min for 3 seconds to generate a fiber separation processing section, and pulls out the fiber separation processing means in 0.2 seconds. , and the operation of stabbing again was repeated to separate the widened reinforcing fiber bundle (4) to obtain a reinforcing fiber bundle (4) having an average number of fibers in the bundle of 1,180 and an average bundle width of 0.6 mm. .

Subsequently, the obtained reinforcing fiber bundle (4) is continuously inserted into a rotary cutter to cut the fiber bundle into fiber lengths of 15 mm, and the fibers are scattered so as to be uniformly dispersed, so that the fiber orientation is isotropic. A discontinuous fiber nonwoven was obtained. The fabric weight of the obtained discontinuous fiber nonwoven fabric was 0.25 kg/m ² . Next, after laminating so that the weight ratio of the discontinuous fiber nonwoven fabric and the resin sheet (1) is 45:55, the whole is sandwiched between stainless steel plates, preheated at 270° C. for 90 seconds, and then a pressure of 2.0 MPa is applied. It was hot-pressed at 240° C. for 180 seconds. Then, it was cooled to 50° C. under pressure to obtain a fiber-reinforced resin molding material having a thickness of 2 mm. At this time, the coating amount of the resin was adjusted at the stage of producing the resin sheet so that the weight content of the reinforcing fiber in the fiber-reinforced resin molding material was 46% by weight. The obtained fiber-reinforced resin molding material was evaluated for mechanical properties and fluidity test. Table 2 shows the results.

(Example 25 [Reference Example] )
The reinforcing fiber bundle (4) is unwound at a constant speed of 10 m/min using a winder, passed through a vibrating widening roll that vibrates in the axial direction at 10 Hz, subjected to widening treatment, and then passed through a width regulating roll to a width of 34 mm. A widened fiber bundle was obtained.

A mother liquor dissolved in water was adjusted so that the ratio of phenol, which is a cross-linking agent, to the additional sizing agent (2) was 0.04, and a reinforcing fiber bundle ( 4) and dried with a hot roller at 250° C. for 0.2 minutes. As shown in Table 1, the number of fibers per unit width of the reinforcing fiber bundle (4) was 1,480/mm, the bundle thickness was 0.08 mm, the drape value was 142 mm, and the bundle hardness was 89 g.

An iron plate for fiber separation treatment having a protruding shape with a thickness of 0.2 mm, a width of 3 mm and a height of 20 mm was placed on the obtained wide reinforcing fiber bundle (4) to which the sizing agent was applied in the width direction of the reinforcing fiber bundle. A fiber separating means was set in parallel at regular intervals of 1 mm. This separating means was intermittently inserted into and removed from the widened fiber bundle to obtain a separated fiber bundle. At this time, the fiber separation processing means pierces the widened fiber bundle traveling at a constant speed of 10 m/min for 3 seconds to generate a fiber separation processing section, and pulls out the fiber separation processing means in 0.2 seconds. , and the operation of stabbing again was repeated to separate the widened reinforcing fiber bundle (4) to obtain a reinforcing fiber bundle (4) having an average number of fibers in the bundle of 1,320 and an average bundle width of 0.02 mm. .

Subsequently, the obtained reinforcing fiber bundle (4) is continuously inserted into a rotary cutter to cut the fiber bundle into fiber lengths of 15 mm, and the fibers are scattered so as to be uniformly dispersed, so that the fiber orientation is isotropic. A discontinuous fiber nonwoven was obtained. The fabric weight of the obtained discontinuous fiber nonwoven fabric was 0.25 kg/m ² . Next, after laminating so that the weight ratio of the discontinuous fiber nonwoven fabric and the resin sheet (1) is 45:55, the whole is sandwiched between stainless steel plates, preheated at 270° C. for 90 seconds, and then a pressure of 2.0 MPa is applied. It was hot-pressed at 240° C. for 180 seconds. Then, it was cooled to 50° C. under pressure to obtain a fiber-reinforced resin molding material having a thickness of 2 mm. At this time, the coating amount of the resin was adjusted at the stage of producing the resin sheet so that the weight content of the reinforcing fiber in the fiber-reinforced resin molding material was 46% by weight. The obtained fiber-reinforced resin molding material was evaluated for mechanical properties and fluidity test. Table 2 shows the results.

(Comparative Example 4)
The reinforcing fiber bundle (4) is unwound at a constant speed of 10 m/min using a winder, passed through a vibrating widening roll that vibrates in the axial direction at 10 Hz, subjected to widening treatment, and then passed through a width regulating roll to a width of 39 mm. A widened fiber bundle was obtained.

A mother liquor is prepared by dissolving the additional sizing agent (4) in water, and is applied to the reinforcing fiber bundle (4) by an immersion method so as to have an adhesion amount of 2.7% by weight. Drying was carried out for 5 minutes. As shown in Table 1, the number of fibers per unit width of the reinforcing fiber bundle (4) was 1,270/mm, the bundle thickness was 0.07 mm, the drape value was 112 mm, and the bundle hardness was 38 g.

An iron plate for fiber separation treatment having a protruding shape with a thickness of 0.2 mm, a width of 3 mm and a height of 20 mm was placed on the obtained wide reinforcing fiber bundle (4) to which the sizing agent was applied in the width direction of the reinforcing fiber bundle. A fiber separating means was set in parallel at regular intervals of 1 mm. This separating means was intermittently inserted into and removed from the widened fiber bundle to obtain a separated fiber bundle. At this time, the fiber separation processing means pierces the widened fiber bundle traveling at a constant speed of 10 m/min for 3 seconds to generate a fiber separation processing section, and pulls out the fiber separation processing means in 0.2 seconds. , and the operation of stabbing again was repeated to separate the widened reinforcing fiber bundle (4) to obtain a reinforcing fiber bundle (4) having an average number of fibers in the bundle of 970 and an average bundle width of 0.6 mm.

Subsequently, an attempt was made to continuously insert the obtained reinforcing fiber bundle (4) into a rotary cutter to cut the fiber bundle, but the fiber bundle was wound around the bobbin and the cutter, and a molding material could not be produced.

(Comparative Example 5)
The reinforcing fiber bundle (1) is unwound at a constant speed of 10 m/min using a winder, passed through a vibrating widening roll that vibrates in the axial direction at 10 Hz, subjected to widening treatment, and then passed through a width regulating roll to a width of 41 mm. A widened fiber bundle was obtained.

As shown in Table 1, the number of fibers per unit width of the reinforcing fiber bundle (1) was 1,230/mm, the bundle thickness was 0.07 mm, the drape value was 54 mm, and the bundle hardness was 27 g.

An iron plate for fiber separation treatment having a protruding shape with a thickness of 0.07 mm, a width of 3 mm, and a height of 20 mm was placed on the obtained wide reinforcing fiber bundle (1) to which the sizing agent was applied, in the width direction of the reinforcing fiber bundle. A fiber separating means was set in parallel at regular intervals of 1 mm. This separating means was intermittently inserted into and removed from the widened fiber bundle to obtain a separated fiber bundle. At this time, the fiber separation processing means pierces the widened fiber bundle traveling at a constant speed of 10 m/min for 3 seconds to generate a fiber separation processing section, and pulls out the fiber separation processing means in 0.2 seconds. , and the operation of stabbing again was repeated to separate the widened reinforcing fiber bundle (1) to obtain a reinforcing fiber bundle (1) having an average number of fibers in the bundle of 930 and an average bundle width of 0.6 mm.

Subsequently, an attempt was made to continuously insert the obtained reinforcing fiber bundle (1) into a rotary cutter to cut the fiber bundle, but the fiber bundle was wound around the bobbin and the cutter, and a molding material could not be produced.

INDUSTRIAL APPLICABILITY The present invention can provide reinforcing fiber bundles and chopped fiber bundles that are excellent in productivity, fluidity during molding, and mechanical properties of molded products, a method for producing the same, and a fiber-reinforced resin molding material using the same. The reinforcing fiber bundle obtained by the production method of the present invention is a material for a discontinuous reinforcing fiber composite, and is suitable mainly for automobile interiors and exteriors, electrical and electronic device housings, bicycles, aircraft interior materials, transportation boxes, and the like. Used.

100 Fiber bundle 110 Separating section 120 Entangling accumulation section 130 Un-split section 140 Fluff pool 150 Separating section 160 Entangling section 170 Separating distance 180 Separating fiber bundle 200 Separating means 210 Protruding section 211 Contact section 220 Rotating separating means 240 Rotating shaft 300 Separating treatment process 301 Fiber bundle widening process 400 Sizing agent application process 401 Sizing agent application process 402 Drying process 501 Cutting surface (1) to (4) Separating means movement direction A to J Pattern a, b fiber bundle running direction

Claims (13)

A widening step ( I), and further comprising a sizing agent applying step (II) of applying a second sizing agent containing a water-soluble polyamide to the widened reinforcing fibers and then reacting with a cross-linking agent to produce a reinforcing fiber bundle . A method for manufacturing a reinforcing fiber bundle. 2. The method for producing a reinforcing fiber bundle according to claim 1 , wherein said cross-linking agent comprises at least one resin selected from melamine resin, urea resin, phenol resin and epoxy resin. 3. The method for producing a reinforcing fiber bundle according to claim 1, wherein the weight ratio of said cross-linking agent and said second sizing agent is 0.02 or more and 1 or less. In the sizing agent application step (II), the second sizing agent is applied so that the total sizing agent adhesion amount of the reinforcing fiber bundle is 0.5% by weight or more and 5% by weight or less. Item 4. A method for producing a reinforcing fiber bundle according to any one of Items 1 to 3 . 5. The reinforcement according to any one of claims 1 to 4 , characterized in that in the width-widening step (I), the width is widened so that the number of single yarns per unit width of the reinforcing fiber bundle is 1,600/mm or less. A method for producing a fiber bundle. The method for producing a reinforcing fiber bundle according to any one of claims 1 to 5 , comprising a step of heat-treating the reinforcing fibers to which the water-soluble polyamide has been applied. The method for producing a reinforcing fiber bundle according to claim 6 , wherein the heat treatment temperature is 130 to 350°C. The method for producing a reinforcing fiber bundle according to claim 6 or 7 , characterized in that the heat treatment time is 0.33 to 15 minutes. The method for producing a reinforcing fiber bundle according to any one of claims 6 to 8, wherein the water-soluble polyamide after heat treatment has an ester bond and/or a carbon-carbon double bond. Any one of claims 1 to 9 , wherein the water-soluble polyamide is obtained by polymerizing a diamine having a tertiary amino group and/or an oxyethylene group in the main chain and a dicarboxylic acid. The method for producing a reinforcing fiber bundle according to 1. The method for producing a reinforcing fiber bundle according to any one of claims 1 to 10 , comprising a step of separating the reinforcing fibers. A separating step (III) of inserting a separating means having a plurality of projecting portions into the reinforcing fiber bundle while running the reinforcing fiber bundle along the longitudinal direction to generate a separating portion;
an entangling step (IV) of forming an entangled portion in which single yarns are entangled at a contact portion between the projecting portion and the reinforcing fiber bundle in at least one of the fiber separating units;
a re-inserting step (V) of extracting the separating means from the reinforcing fiber bundle, passing the separating means through an entangled accumulation portion including the entangled portion, and then thrusting the separating means into the reinforcing fiber bundle again;
12. The method according to any one of claims 1 to 11 , further comprising a splitting treatment step (VI) for alternately forming splitting treatment sections divided into a plurality of bundles and unsplitting treatment sections. A method for producing a reinforcing fiber bundle. 13. The reinforcing fiber bundle according to claim 12 , wherein, in the fiber separation treatment step (VI), the lengths of the fiber separation treatment sections adjacent to each other with one non-fiber separation treatment section interposed therebetween include different lengths. Production method.

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