JP2010126702A - Epoxy resin composition, fiber-reinforced composite material, and methods for producing them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fiber-reinforced composite material having high adhesion between epoxy resin composition and reinforcing fibers, being excellent in impact resistance and fatigue characteristics, and most suited as a member such as a primary aircraft structural member. <P>SOLUTION: There is provided an epoxy resin composition comprising at least the following constitutional elements [A], [B], [C], [D], and [E]: [A] an epoxy resin having three or more epoxy groups in the molecule, [B] an epoxy resin having one diglycidylaniline skeleton and two epoxy groups in the molecule, [C] a polyethylene glycol diglycidyl ether having the number n of repeating units of 5 or larger, [D] a liquid aromatic diamine having a viscosity of 500 mPa s or lower at 70°C, and [E] core/shell polymer particles. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an epoxy resin composition suitable for application to a fiber-reinforced composite material used for aircraft members, spacecraft members, automobile members, ship members, and the like, particularly an epoxy resin composition suitable for a resin transfer molding method. In addition, an epoxy resin composition having low viscosity, high heat resistance, and high elastic modulus, and extremely excellent adhesion to the reinforcing fiber, and the reinforcing fiber and the epoxy resin by using the epoxy resin composition The present invention relates to a fiber-reinforced composite material having a high adhesive property and excellent fatigue resistance.

  Conventionally, fiber reinforced composite materials consisting of reinforcing fibers such as glass fiber, carbon fiber and aramid fiber, and thermosetting resins such as unsaturated polyester resin, vinyl ester resin, epoxy resin, phenol resin, cyanate resin and bismaleimide resin have been Because it is lightweight, it has excellent mechanical properties such as strength and rigidity, heat resistance, and corrosion resistance, so it can be used in many fields such as aircraft, spacecraft, automobiles, railway vehicles, ships, civil engineering and sports equipment. It has been. Especially in applications where high performance is required, fiber reinforced composite materials using continuous reinforcing fibers are used, carbon fibers with excellent specific strength and specific elastic modulus are used as reinforcing fibers, and thermosetting is used as a matrix resin. Of these, epoxy resins having a good balance of mechanical properties, heat resistance and chemical resistance are often used.

  A fiber reinforced composite material using carbon fibers as reinforced fibers can be reduced in weight relative to metal due to excellent mechanical properties. Therefore, in recent years, application to aircraft members has been progressing.

  When applying a fiber reinforced composite material to an aircraft member, it is important to suppress impact resistance and fatigue characteristics, in particular, thermal stress generated during thermoforming and cracks generated by a thermal cycle test (environmental fatigue test). Cracks generated due to impact resistance and fatigue characteristics often occur near the interface between the reinforcing fiber having the lowest strength in the fiber-reinforced composite material and the epoxy resin. Therefore, in order to improve the impact resistance and fatigue characteristics, it is effective to increase the adhesion between the reinforcing fiber and the epoxy resin.

  Methods for evaluating the adhesion between the reinforcing fiber and the epoxy resin include a 90-degree tensile strength test and an in-layer shear strength test (ILSS). Among them, the 90-degree tensile strength is preferably used because the adhesion can be evaluated purely. It has been.

  Examples of a method for improving the adhesion between the reinforcing fiber and the epoxy resin include a method of dissolving a specific thermoplastic resin in the epoxy resin (Patent Documents 1 to 3) and a method of adding an epoxy resin having a special skeleton ( Patent Document 4) has been proposed.

  However, these methods significantly increase the viscosity of the matrix resin, and the method for producing the fiber-reinforced composite material is limited to a method using a prepreg in which the reinforcing fiber is impregnated with the matrix resin in advance.

  In recent years, low-cost manufacturing methods that do not require expensive equipment such as an autoclave, such as a resin transfer molding method, have attracted attention because there are few steps for manufacturing fiber-reinforced composite materials. In the resin transfer molding method, since the liquid matrix resin is injected or impregnated by pressurizing or depressurizing a woven fabric containing reinforcing fibers, the viscosity of the matrix resin is limited, and the above-described method for improving adhesion cannot be applied.

Therefore, a method for improving the adhesion between the reinforcing fiber and the epoxy resin that does not significantly increase the viscosity has been desired.
JP-A-63-37135 JP-A-63-37136 JP-A-63-37137 Japanese Patent Application Laid-Open No. 9-130038

  In view of the background of such conventional technology, an object of the present invention is to apply an epoxy resin composition having high heat resistance, high elastic modulus, low viscosity and excellent adhesion to reinforcing fibers, and the epoxy resin composition. It is an object of the present invention to provide a fiber-reinforced composite material that has excellent adhesive properties and is optimal as a member of an aircraft primary structure or the like.

The present invention employs the following means in order to solve such problems. That is, the epoxy resin composition of the present invention is an epoxy resin composition characterized by including at least the following components [A], [B], [C], [D] and [E].
[A] Epoxy resin having three or more epoxy groups in one molecule [B] Epoxy resin having one diglycidylaniline skeleton in one molecule and two epoxy groups [C] The number of repeating units n is Polyethylene glycol diglycidyl ether [D] which is 5 or more Liquid aromatic diamine [E] core-shell polymer particles whose viscosity at 70 ° C. is 500 mPa · s or less.

  According to a preferred embodiment of the epoxy resin composition of the present invention, the epoxy resin composition is composed of a main agent containing at least constituent elements [A], [B], [C] and [E] and a curing agent containing at least constituent element [D]. , A two-pack type epoxy resin composition in which a main agent and a curing agent are mixed when used, and the viscosity of the main agent at 70 ° C. is 500 mPa · s or less, and the viscosity of the curing agent at 70 ° C. is 500 mPa · s or less. Yes, at 70 ° C., the viscosity of the composition obtained by mixing the main agent and the curing agent is 500 mPa · s or less within 5 minutes from the start of measurement, and the time until the viscosity reaches 1000 mPa · s is 60 minutes or more. . Here, the viscosity of the mixture at 70 ° C. is measured according to JIS Z8803 (1991) “Viscosity measurement method using a cone-plate rotational viscometer” and equipped with a standard cone rotor (1 ° 34 ′ × R24). Using a viscometer (produced by Tokimec Co., Ltd., TVE-30H), the rotation speed is 50 rpm.

  A preferred fiber-reinforced composite material of the present invention is composed of at least the epoxy resin composition and carbon fibers. According to a further preferred embodiment, the carbon fiber substrate used is a warp comprising strands of the carbon fibers and the same. Auxiliary warp of a fiber bundle made of glass fiber or chemical fiber arranged in parallel to the fiber, and weft made of glass fiber or chemical fiber arranged so as to be orthogonal thereto, and the auxiliary warp and the weft intersect each other By this, it is a non-crimp woven fabric in which carbon fiber strands are held together to form a woven fabric.

  Furthermore, a preferred method for producing the fiber-reinforced composite material of the present invention is to dispose a non-crimp structure woven fabric containing carbon fibers as described above in a mold, inject and impregnate the epoxy resin composition, and then heat cure. This is the so-called resin transfer molding (RTM) method.

  According to the present invention, an epoxy resin composition excellent in heat resistance and elastic modulus and excellent in adhesion to reinforcing fibers is obtained while maintaining a low viscosity suitable for the resin transfer molding method. Fiber reinforced composite material composed of epoxy resin composition and reinforced fiber is excellent in impact resistance and fatigue resistance, so it is suitable for structural members such as aircraft members, spacecraft members, automobile members and ship members can do.

  The epoxy resin composition of the present invention comprises at least an epoxy resin having a specific skeleton in the molecule and a liquid aromatic diamine.

  In the present invention, the epoxy resin refers to a compound having two or more epoxy groups in one molecule. The epoxy resin composition is an epoxy resin, a component for curing the epoxy resin (generally referred to as a curing agent, a curing catalyst, or a curing accelerator), and a modifier (plasticizer, Dye, organic pigment and inorganic filler, polymer compound, antioxidant, UV absorber, coupling agent, surfactant, etc.) It refers to a high molecular weight polymer that has been polymerized until the epoxy resin composition is heated to undergo a crosslinking reaction and has a glass transition temperature of at least 50 ° C. or higher.

  The epoxy resin having 3 or more epoxy groups in one molecule, which is the constituent element [A] used in the epoxy resin composition of the present invention, is a cured product obtained by heating and curing the epoxy resin composition of the present invention. It is blended to increase the heat resistance. Examples of the constituent element [A] include novolac epoxy resins such as phenol novolac epoxy resins and cresol novolac epoxy resins, N, N, O-triglycidyl-m-aminophenol, N, N, O-triglycidyl. -P-aminophenol, N, N, O-triglycidyl-4-amino-3-methylphenol, N, N, N ', N'-tetraglycidyl-4,4'-methylenedianiline, N, N, Glycidylamine type epoxy resins such as N ′, N′-tetraglycidyl-2,2′-diethyl-4,4′-methylenedianiline, N, N, N ′, N′-tetraglycidyl-m-xylylenediamine Etc. may be used alone or in combination of two or more. In particular, N, N, N ′, N′-tetraglycidyl-4,4′-methylenedianiline has a high effect of increasing heat resistance and is excellent in chemical resistance of a cured product, and N, N, O -Triglycidyl-p-aminophenol can be preferably used because it has a very low viscosity among epoxy resins having an effect of improving heat resistance and has an effect of lowering the viscosity of the epoxy resin composition.

  In the present invention, the amount of component [A] is preferably 40 to 85 parts by weight, more preferably 45 to 75 parts by weight, based on 100 parts by weight of the total epoxy resin. By setting the blending amount of the epoxy resin to 40 parts by weight or more in 100 parts by weight of the total epoxy resin, the glass transition temperature of the resulting cured product, and thus the fiber reinforced composite material composed of the cured epoxy resin and the reinforcing fiber, is increased. Further, when the epoxy resin is 85 parts by weight or less with respect to 100 parts by weight of the total epoxy resin, a decrease in fracture toughness of the cured epoxy resin is suppressed, and the epoxy resin is suitable for the fiber-reinforced composite material.

  The component [B] used in the epoxy resin composition of the present invention, which has one diglycidylaniline skeleton in one molecule and has two epoxy groups, heats the epoxy resin composition of the present invention. It mix | blends in order to reduce the viscosity of the hardened | cured material obtained by hardening, and to raise the elasticity modulus of the hardened | cured material obtained by heat-curing. Examples of the component [B] include N, N-diglycidylaniline and N, N-diglycidyl-o-toluidine.

  In the present invention, the amount of component [B] is preferably 10 to 55 parts by weight, more preferably 15 to 50 parts by weight, based on 100 parts by weight of the total epoxy resin. By setting the blending amount of the epoxy resin to 10 parts or more in 100 parts by weight of the total epoxy resin, the viscosity of the resulting epoxy resin composition is lowered, and the elastic modulus of the cured product obtained by heat curing is increased. The compression characteristics of the fiber reinforced composite material composed of the cured resin and the reinforced fiber can be improved. Further, when the epoxy resin is 55 parts by weight or less based on 100 parts by weight of the total epoxy resin, the heat resistance of the epoxy resin, It is suitable for a fiber-reinforced composite material by suppressing a decrease in fracture toughness.

  The polyethylene glycol diglycidyl ether having a repeating unit number n of 5 or more, which is the constituent element [C] used in the epoxy resin composition of the present invention, is a woven fabric containing the epoxy resin composition of the present invention, carbon fibers, and at least carbon fibers. It is blended in order to improve the adhesion to the materials used in the above, specifically glass fiber, polyamide fiber, aramid fiber and the like. In addition, the number of repeating units in the component [C] is the number of repeating ethylene groups present in one molecule.

  Examples of the polyethylene glycol diglycidyl ether include “Denacol (registered trademark)” EX-850 and EX-851 (n = 2), EX-821 (n = 4), EX- manufactured by Nagase ChemteX Corporation. 830 and EX-832 (n = 9), EX-841 (n = 13), EX-861 (n = 22) are SR-2EG (n = 2), SR-manufactured by Sakamoto Pharmaceutical Co., Ltd. There are 8EG (n = 9), and the effect of improving the adhesion which is the object of the present invention is obtained because the number of repeating units n is 5 or more, preferably n is 6 to 22, more preferably n is 7 to 13, Most preferably, n is 9.

  Further, even when a linear aliphatic epoxy resin such as polyethylene glycol diglycidyl ether, for example, neopentyl glycol diglycidyl ether, fatty acid-modified epoxy resin or the like is used, the effect of improving the adhesiveness as much as the component [C] of the present invention is obtained. Not expressed.

  The reason why the component [C] of the present invention improves the adhesiveness with the reinforcing fiber is that functional groups capable of reacting with the epoxy resin in order to improve the adhesiveness with the reinforcing fiber, particularly the epoxy resin, such as a hydroxyl group and a carboxyl group In the case of carbon fiber introduced with a surface treatment, the surface energy is extremely high, so components with low surface energy are likely to approach. Among the components constituting the present invention, a component having a low surface energy is an aliphatic epoxy resin containing the component [C].

  However, even in the case of an aliphatic epoxy resin, those having a low molecular weight, that is, those having a repeating unit number n of polyethylene glycol diglycidyl ether smaller than 5 in the present invention, neopentyl glycol diglycidyl ether, etc. Since the crosslink density of the cured product in the vicinity of the interface of the epoxy resin composition is increased, the toughness is reduced, brittle fracture is easily caused, and the strength is reduced. On the other hand, those having a high molecular weight, that is, those having a number of repeating units n of polyethylene glycol diglycidyl ether greater than 22 in the present invention, fatty acid-modified epoxy resins, such as castor oil-modified epoxy resins and dimer acid-modified epoxy resins, are crosslinked. Since the density is too low and the rigidity cannot be maintained, the strength decreases.

  As a result of intensive studies, the present inventor has found that the number of repeating units n of the constituent element [C] of the present invention is 5 or more, preferably n is 6 to 22, more preferably n is 7 to 13, and most preferably n is n. No. 9 polyethylene glycol diglycidyl ether has been found to improve the adhesion to reinforcing fibers and maintain a suitable strength.

  In the present invention, the compounding amount of the component [C] is preferably 5 to 10 parts by weight, more preferably 6 to 8 parts by weight, based on 100 parts by weight of the total epoxy resin. Improved adhesion between the epoxy resin composition obtained by setting the amount of the epoxy resin to 5 parts by weight or more in 100 parts by weight of the total epoxy resin and the material used for the reinforcing fiber and the fabric including at least the reinforcing fiber. As a result, the adhesive properties and compression properties of the fiber reinforced composite material comprising the cured product and the reinforcing fibers can be improved. Further, the epoxy resin can be 10 parts by weight or less with respect to 100 parts by weight of the total epoxy resin. It suppresses that the heat resistance of the hardened | cured material obtained by heat-curing falls and becomes suitable for a fiber reinforced composite material.

  The liquid aromatic diamine which is the component [D] used in the epoxy resin composition of the present invention is a curing agent for crosslinking and curing the epoxy resins of the components [A], [B] and [C]. Yes, the viscosity at 70 ° C. is 500 mPa · s or less, and the more preferable viscosity is 400 mPa · s or less. The viscosity was measured in accordance with JIS Z8803 (1991) "Viscosity measurement method using a cone-plate rotary viscometer" and an E-type viscometer equipped with a standard cone rotor (1 ° 34 '× R24) (Tokimec Co., Ltd.). Using a TVE-30H, manufactured at a rotational speed of 50 rpm. When the viscosity at 70 ° C. is higher than 500 mPa · s, the viscosity of the resulting epoxy resin composition becomes too high, and when a fiber-reinforced composite material is molded by the resin transfer molding method, the fabric containing reinforcing fibers is pressurized. Alternatively, it cannot be injected under reduced pressure, and an unimpregnated portion of the epoxy resin composition is generated in the obtained fiber-reinforced composite material, which is not preferable because mechanical properties may be deteriorated. The lower limit of the viscosity at 70 ° C. is not particularly limited, and the lower the viscosity, the easier the injection impregnation of the epoxy resin composition in the resin transfer molding is preferable.

  As the component [D], for example, diethyltoluenediamine (a mixture containing 2,4-diethyl-6-methyl-m-phenylenediamine and 4,6-diethyl-2-methyl-m-phenylenediamine as main components), 2,2'-diethyl-4,4'-methylenedianiline, 2,2'-isopropyl-6,6'-dimethyl-4,4'-methylenedianiline, 2,2 ', 6,6' tetraisopropyl Examples thereof include alkyl group derivatives of diaminodiphenylmethane such as -4,4'-methylenedianiline and polyoxytetramethylene bis (p-aminobenzoate). Of these, diethyltoluenediamine having a low viscosity and excellent physical properties as a cured product such as a glass transition temperature can be preferably used. Solid aromatic polyamine can be mix | blended with the component [D] in the range which does not exceed the viscosity mentioned above. As solid aromatic polyamines, 3,3′-diaminodiphenyl sulfone and 4,4′-diaminodiphenyl sulfone can provide a cured product having excellent heat resistance and elastic modulus, and further, thermal expansion is reduced due to linear expansion coefficient and moisture absorption. Can be used preferably. In general, diaminodiphenyl sulfone has a strong crystallinity, and even if it is mixed with liquid aromatic polyamine at a high temperature to form a liquid, it tends to precipitate as a crystal in the cooling process. However, two isomers of diaminodiphenyl sulfone and liquid aromatic polyamine are used. In the case of mixing, it is preferable that crystal precipitation is much less likely to occur than a mixture of a single diaminodiphenyl sulfone and a liquid aromatic polyamine. The amount of diaminodiphenyl sulfone is preferably 10 to 40 parts by weight, more preferably 20 to 35 parts by weight, per 100 parts by weight of the wholly aromatic amine. If the blending amount is 10 parts by weight or more, the effect of the cured product as described above can be easily obtained, and if the blending amount is 40 parts by weight or less, the precipitation of crystals is easily suppressed. When 3,3′-diaminodiphenylsulfone and 4,4′-diaminodiphenylsulfone are used in combination in order to suppress the precipitation of crystals, the weight ratio of both is preferably 10:90 to 90:10, The closer the ratio between the two, the higher the effect of suppressing crystal precipitation.

  In this invention, the compounding quantity of component [D] is the quantity from which the active hydrogen in component [D] becomes the range of 0.7-1.3 with respect to one epoxy group of all the epoxy resins. It is preferable to blend so as to be 0.8 to 1.2. Active hydrogen refers to a highly reactive hydrogen atom bonded to nitrogen, oxygen, or sulfur in an organic compound. When the ratio between the epoxy group and the active hydrogen is out of the above range, the heat resistance and elastic modulus of the obtained resin cured product may be lowered.

  It is known that the aromatic diamine used in the component [D] of the present invention generally has a slow progress of the crosslinking reaction. Therefore, a curing accelerator can be blended with the component [D] of the present invention to accelerate the reaction. When the curing accelerator is blended in the component [D], the concentration of the curing accelerator is uniform even in the reinforcing fiber bundle when the fiber reinforced composite material of the present invention is used to produce the fiber reinforced composite material. It is preferable that the shape is small enough to be impregnated as it is. Specifically, the volume average particle diameter is 0.5 μm or less, more preferably 0.1 μm or less. Most preferably, the aromatic diamine used in the constituent element [D] of the present invention is completely dissolved until there is no solid content. It is in a dissolved state. By satisfying the above requirements, a fiber-reinforced composite material exhibiting stable mechanical properties can be obtained. Here, the completely dissolved state means a liquid material that dissolves and does not have a solid component and has no concentration distribution, and even when the liquid material is stored at 25 ° C. for one month or longer. Means that it is kept in a state where no precipitation occurs.

  As the curing accelerator to be blended with the component [D] of the present invention, for example, a curing accelerator such as a tertiary amine, Lewis acid complex, onium salt, imidazole and the like may be blended, but the resin transfer molding method is used. In the case of molding a fiber reinforced composite material, the increase in viscosity during resin injection must be suppressed. t-Butylcatechol is suitable for the resin transfer molding method because it has little reaction promoting effect at the temperature (50-80 ° C.) at the time of resin injection and increases in a temperature range of 100 ° C. or higher.

  In this invention, it is preferable that the compounding quantity in the case of mix | blending a hardening accelerator with component [D] is 0.5-3 weight part with respect to 100 weight part of all the epoxy resins, More preferably, 1-2. It is to mix 5 parts by weight. If the amount of t-butylcatechol is out of this range, the balance between the increase in viscosity at the time of resin injection and the reaction rate at high temperature is lost, which is not preferable.

  The core-shell polymer particles that are the constituent element [E] used in the epoxy resin composition of the present invention are a shell different from the core component on the surface of the particulate core component mainly composed of a crosslinked rubbery polymer or elastomer. By graft polymerization of the component polymer, a part or the whole of the surface of the particulate core component is coated with the shell component, and the fracture toughness of the cured product can be greatly improved by adding a small amount.

  The core component constituting the core-shell polymer includes a polymer or silicone resin polymerized from one or more selected from a conjugated diene monomer, acrylic acid and / or methacrylic acid ester monomer, and is particularly conjugated diene-based. What applied the bridge | crosslinked polybutadiene which superposed | polymerized the butadiene which is a monomer as a core component can be used suitably, since it is excellent in the improvement of fracture toughness at very low temperature.

  The shell component that constitutes the core-shell polymer is preferably graft-polymerized to the above-described core component, and is preferably chemically bonded to the polymer that constitutes the core component. The component constituting the shell component is, for example, a polymer polymerized from one or more selected from (meth) acrylic acid esters, aromatic vinyl compounds and the like.

  The shell component preferably has a functional group that reacts with the epoxy resin composition of the present invention in order to stabilize the dispersion state. Examples of such functional groups include a hydroxyl group, a carboxyl group, and an epoxy group.

  There is no restriction | limiting in particular as a core shell polymer applicable to the epoxy resin composition of this invention, The thing manufactured by the well-known method can be used. However, the core-shell polymer is usually handled as a powder by pulverizing what is taken out as a lump, and the powder-like core-shell polymer is often dispersed again in the epoxy resin. It is difficult to disperse stably. Therefore, it is preferable that the core-shell polymer can be handled in the form of a masterbatch that is finally dispersed in the epoxy resin without being taken out in a lump from the production process of the core-shell polymer. For example, JP-A-2004-315572 Obtained by obtaining a suspension in which the core-shell polymer is dispersed by polymerizing by the method described in the publication, that is, by polymerizing the core-shell polymer in an aqueous medium represented by emulsion polymerization, dispersion polymerization, and suspension polymerization. The suspension is mixed with water and an organic solvent that is partially soluble, for example, an ether solvent such as acetone or methyl ethyl ketone, and then brought into contact with a water-soluble electrolyte such as sodium chloride or potassium chloride. After separating the water layer, the epoxy resin is mixed with the core-shell polymer-dispersed organic solvent obtained by separating and removing the aqueous layer. And a method for evaporating and removing the medium can be used. As the core-shell polymer-dispersed epoxy masterbatch produced by the production method, “Kane Ace (registered trademark)” commercially available from Kaneka Corporation can be suitably used.

  When the core-shell polymer is applied to the epoxy resin composition of the present invention, the core-shell polymer preferably has an average particle diameter of 1 to 500 nm in terms of volume average particle diameter, and more preferably 3 to 300 nm. The volume average particle diameter can be measured using a nanotrack particle size distribution analyzer (manufactured by Nikkiso Co., Ltd.). When the volume average particle size of the core-shell polymer used in the present invention is 1 nm or less, it is difficult to produce or very expensive and cannot be used substantially. When the volume average particle size is 500 nm or more, fibers are used. In the step of injecting and impregnating the epoxy resin composition in the molding process of the reinforced composite material, it is not preferable because it is filtered by the reinforced fiber and the dispersion state may become non-uniform in the fiber reinforced composite material.

  In the present invention, the amount of component [E] is preferably 0.5 to 10 parts by weight, more preferably 1 to 8 parts by weight, based on 100 parts by weight of the total epoxy resin. If the blending amount is 0.5 parts by weight or more, the fracture toughness required for the fiber-reinforced composite material after molding is easily obtained, and if the blending amount is 10 parts by weight or less, the resulting epoxy resin composition It becomes more suitable for molding a fiber-reinforced composite material by a resin transfer molding method in which the viscosity of the product is suppressed and injected into and impregnated into the reinforcing fiber.

  In addition to the constituent elements [A], [B] and [C], other epoxy resins can be blended in the epoxy resin composition of the present invention as long as the viscosity is not increased and various physical properties are not deteriorated. Examples of such epoxy resins include bisphenol-type epoxy resins such as bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol AD diglycidyl ether, and bisphenol S diglycidyl ether, and brominated epoxy resins such as tetrabromobisphenol A diglycidyl ether. 1 type of epoxy resin having biphenyl skeleton, epoxy resin having naphthalene skeleton, epoxy resin having dicyclopentadiene skeleton, phenol novolac type epoxy resin, biphenyl aralkyl type epoxy resin, resorcin diglycidyl ether, triglycidyl isocyanurate or the like A plurality of types can be mixed and used.

  In addition, the epoxy resin composition of the present invention includes a monoepoxy compound having only one epoxy group in one molecule, an alicyclic epoxy resin, etc. within a range that does not significantly reduce heat resistance and mechanical properties. It can mix | blend suitably.

  The epoxy resin composition of the present invention includes a plasticizer, a dye, and an organic pigment as long as the physical properties of a cured product obtained by heat-curing, and thus a fiber-reinforced composite material composed of the cured product and reinforcing fibers, are not significantly reduced. Inorganic fillers, polymer compounds, antioxidants, ultraviolet absorbers, coupling agents, surfactants, and the like can be appropriately blended.

  The epoxy resin composition generally contains a one-component type that contains a curing agent that is a component capable of curing the epoxy resin and the epoxy resin in advance, and stores the epoxy resin and the curing agent separately, both of which are used immediately before use. There are two-pack types that use a mixture of the two.

  In the case of a one-pack type epoxy resin composition, since the curing reaction proceeds during storage, the curing agent component has low reactivity and is often selected in a solid form. However, since the curing reaction proceeds little by little at room temperature, it is necessary to store in a frozen state, which increases management costs. In addition, since a solid curing agent is used, in order to impregnate the reinforcing fiber with the one-pack type epoxy resin composition, it is necessary to use a press roll and press it at a high pressure, which increases the manufacturing cost.

  On the other hand, since the two-pack type epoxy resin composition stores the main agent and the curing agent composed of the epoxy resin separately, it can be stored for a long time without any particular limitation on the storage conditions. In addition, by making both the main agent and the curing agent liquid, a mixture obtained by mixing the main agent and the curing agent can also be made into a low-viscosity liquid, and can be used as a simple method for reinforcing fibers such as a resin transfer molding method. Impregnation and molding can be performed.

  The epoxy resin composition of the present invention is not particularly limited to a one-pack type or a two-pack type, but a two-pack type is recommended because of the advantages described above.

  When the epoxy resin composition of the present invention is made into a two-pack type, the main component is a mixture of components [A], [B], [C] and [E] used in the present invention, and is used in the present invention. It is desirable to use a curing accelerator that can be uniformly dissolved in the component [D] and the component [D]. Further, the other components described above can be blended in any way as long as they do not show reactivity with the main component and the curing agent component. When it is reactive with either the main agent or the curing agent, it is desirable to blend it in the direction that does not show reactivity.

  When the epoxy resin composition of the present invention is a two-pack type, the viscosity of the main agent is 500 mPa · s or less at 70 ° C., and the preferred viscosity is 400 mPa · s or less. The viscosity was measured in accordance with JIS Z8803 (1991) "Viscosity measurement method using a cone-plate rotary viscometer" and an E-type viscometer equipped with a standard cone rotor (1 ° 34 '× R24) (Tokimec Co., Ltd.). Using a TVE-30H, manufactured at a rotational speed of 50 rpm. When the viscosity at 70 ° C. is higher than 500 mPa · s, workability such as taking out from the container, weighing, mixing with a curing agent, or degassing treatment may be deteriorated. In order to reduce the viscosity of the main agent at 70 ° C. to 500 mPa · s or less, an epoxy resin having a molecular weight of 500 or more is preferably not blended in 100 parts by weight of the main agent, and a particulate form such as a core-shell polymer. The additive is not blended in an amount of 15 parts by weight or more. The lower limit of the viscosity of the main agent at 70 ° C. is not particularly limited, and the lower the viscosity, the easier the injection impregnation of the epoxy resin composition in the resin transfer molding method is preferable.

  Moreover, when making the epoxy resin composition of this invention into a two-pack type, the viscosity of a hardening | curing agent is 500 mPa * s or less in 70 degreeC, and a preferable viscosity is 400 mPa * s or less. In addition, the measurement of a viscosity is the same as the measuring method of the main ingredient viscosity mentioned above. When the viscosity at 70 ° C. of the curing agent is higher than 500 mPa · s, workability such as taking out from the container, weighing, mixing with the main agent, or degassing treatment may be deteriorated. The lower limit of the viscosity at 70 ° C. is not particularly limited, and the lower the viscosity, the easier the injection impregnation of the epoxy resin composition in the resin transfer molding method is preferable. In order to reduce the viscosity of the curing agent at 70 ° C. to 500 mPa · s or less, as described above, in the component [D] used in the present invention, the amount of diaminodiphenyl sulfone is 100 parts by weight of wholly aromatic amine. No more than 40 parts by weight, and no more than 15 parts by weight of a particulate additive such as a core-shell polymer. The lower limit of the viscosity of the curing agent at 70 ° C. is not particularly limited, and the lower the viscosity, the easier the injection impregnation of the epoxy resin composition in the resin transfer molding method is preferable.

  The epoxy resin composition of the present invention can be cured by heating at an arbitrary temperature in the range of 50 to 200 ° C. for an arbitrary time in the range of 0.5 to 10 hours, so as to advance the crosslinking reaction. The heating condition may be one stage or may be a multistage condition in which a plurality of heating conditions are combined. The higher the curing temperature, the higher the heat resistance of the fiber reinforced composite material. However, the higher the heating temperature in the mold during molding, the higher the cost of equipment and heat source, and the longer the occupation time of the mold, the more economical Sexuality gets worse. Therefore, it is preferable that the initial curing is performed at an arbitrary temperature in the range of 50 to 140 ° C., the molded product is removed from the mold, and the final curing is performed at a relatively high temperature using an apparatus such as an oven.

  Assuming an aircraft structural member, the final curing condition is, for example, a desired resin cured product can be obtained by curing at a temperature of 180 ° C. for 1 to 10 hours.

  The cured product obtained by heat curing the epoxy resin composition of the present invention at 180 ° C. for 2 hours preferably has a flexural modulus of 2.5 to 4.5 GPa at 25 ° C., more preferably 3.0. -4.0 GPa. The flexural modulus is measured according to JIS K7171-1994. By setting the bending elastic modulus in a dry state at 25 ° C. to 2.5 GPa or more, a fiber-reinforced composite material having excellent compression characteristics can be obtained. Designed when used as a structural member, because if the flexural modulus is lower than 2.5 GPa at 25 ° C., the compression properties of the fiber-reinforced composite material using the epoxy resin composition of the present invention may deteriorate. Since the thickness increases, the weight of the member may increase. On the other hand, if the flexural modulus is too higher than 4.5 GPa, the brittleness of the cured product increases and the impact resistance and fatigue resistance tend to decrease.

  It is preferable that the glass transition temperature of the hardened | cured material which heat-cured the epoxy resin composition of this invention over 2 hours at the temperature of 180 degreeC is 160-230 degreeC, More preferably, it is 170-220 degreeC or more. The glass transition temperature is determined according to the method for obtaining the midpoint glass transition temperature described in JIS K7121-1987. By setting the glass transition temperature of the cured product to 160 ° C. or higher, it is possible to maintain a high elastic modulus even in a state where the cured product has absorbed water, and thus to obtain a fiber-reinforced composite material having excellent compression characteristics at high temperature / water absorption. Can do. On the other hand, since the cured product of the epoxy resin composition generally starts thermal decomposition at around 240 ° C., there is a possibility that the mechanical properties will be significantly lowered at 230 ° C. or higher.

  As a method for producing a fiber reinforced composite material using the epoxy resin composition of the present invention, for example, a hand layup method, a hot melt impregnation prepreg method, a wet impregnation prepreg method, a filament winding method, or the like can be used. The epoxy resin composition of the present invention can be suitably used particularly for the production of a fiber-reinforced composite material using a resin transfer molding method. In the resin transfer molding method, a fiber base or preform made of reinforcing fibers is placed in a mold, liquid matrix resin is injected into the mold to impregnate the reinforcing fibers, and then heated. The two-component epoxy resin composition is cured to obtain a fiber-reinforced composite material that is a molded product.

  Examples of the reinforcing fiber used in the present invention include carbon fiber, glass fiber, and aramid fiber, and carbon fiber is preferably used in that a lightweight and high-performance fiber-reinforced composite material can be obtained.

  Specific examples of the carbon fibers in the present invention include acrylic, pitch, and rayon carbon fibers, and acrylic carbon fibers having particularly high tensile strength are preferably used. As the form of the carbon fiber, twisted yarn, untwisted yarn, untwisted yarn and the like can be used, but untwisted yarn or untwisted yarn is preferably used because the balance between moldability and strength characteristics of the fiber reinforced composite material is good.

  The elastic modulus of the carbon fiber is preferably in the range of 200 GPa to 400 GPa from the viewpoint of the characteristics and weight of the molded structural member. If the elastic modulus is lower than this range, the rigidity of the structural member may be insufficient and weight reduction may be insufficient. Conversely, if the elastic modulus is higher than this range, the strength of the carbon fiber generally tends to decrease. A more preferable elastic modulus is in the range of 250 GPa to 370 GPa, and more preferably in the range of 290 GPa to 350 GPa.

  In the present invention, the fiber base material composed of reinforcing fibers is composed of reinforcing fibers alone or in combination with a plurality of types, and further combined with other chemical fibers as necessary, and as a form, the fiber directions are aligned substantially in the same direction. Woven fabrics, knitted fabrics, braids and mats can be used. However, in particular, the reinforcing fiber is substantially used in that a fiber reinforced composite material having high mechanical properties and a high volume content of the reinforcing fiber can be obtained. In particular, a so-called unidirectional fabric that is oriented in one direction and fixed with glass fiber or chemical fiber is preferably used.

  Examples of the unidirectional woven fabric include strands made of carbon fibers arranged in parallel in one direction as warps, and wefts made of glass fibers or chemical fibers intersecting with each other to form a plain weave structure. , Consisting of a warp made of carbon fiber strands, an auxiliary warp of a fiber bundle made of glass fibers or chemical fibers arranged parallel to this, and a weft made of glass fibers or chemical fibers arranged so as to be orthogonal thereto, Non-crimped woven fabrics and the like in which the woven fabric is formed by holding the carbon fiber strands integrally by crossing the auxiliary warps and the wefts.

  In the case of a woven fabric having a plain weave structure, the carbon fiber strands and the wefts are orthogonal to each other, so the carbon fiber strands are bent. The strand of carbon fiber does not bend because it is a weft made of auxiliary warp and glass fiber or chemical fiber. When the strand of carbon fiber is bent, unevenness in volume distribution occupied by the carbon fiber in the strand is generated, and there is a possibility that contact between the single yarns of the carbon fiber occurs. When the contact between the single yarns of carbon fibers occurs, the portion is not impregnated with the epoxy resin composition and becomes a defect, which may reduce the adhesiveness and mechanical properties.

  Therefore, when the non-crimp structure woven fabric in which the strands of carbon fibers are not bent is used as a fiber base material and the epoxy resin composition of the present application is combined, the effect of improving adhesiveness is maximized, which is particularly preferable.

  A binder can be appropriately attached to the fiber base material for the purpose of preventing the orientation deviation of the reinforcing fibers, temporarily adhering the fiber base materials, and improving the impact resistance of the resulting fiber reinforced composite material. .

  There are no particular restrictions on the composition of the binder, and existing ones can be used. However, those containing a thermoplastic resin as the main component can be preferably used because they have little change in physical properties during storage in addition to the above-mentioned purpose.

  When the fiber-reinforced composite material of the present invention is used as an aircraft structural member, excellent heat resistance is required, and therefore an engineering plastic having a high glass transition temperature is preferable as the thermoplastic resin used for the binder. In particular, polysulfone, polyethersulfone, polyimide, polyetherimide and the like can be preferably used.

The binder may be attached to one or both surfaces of the fibrous base material, coating weight is preferably 5 to 50 g / ^{m 2} in basis weight, and more preferably from 10 to 45 g / ^{m 2.} By setting it to 5 g / m ² or more, the above-mentioned purpose can be satisfied, and by setting it to 50 g / m ² or less, impregnation with the epoxy resin composition of the present invention is not hindered, and a molded body without voids can be obtained. .

  In the present invention, the fiber reinforced composite material preferably has a reinforcing fiber volume content of 50 to 65%, and more preferably 53 to 60%. When the volume content is less than the above range, the weight of the fiber-reinforced composite material becomes heavy, and the strength tends to decrease due to the influence of stress concentration. Further, when the volume content of the reinforcing fiber is larger than the above range, a defect portion such as an unimpregnated portion or a void is very often generated inside the fiber reinforced composite material, which may cause deterioration in physical properties.

  As a preferable molding method of the fiber-reinforced composite material in the present invention, the epoxy resin composition of the present invention is preferably applied at an arbitrary temperature in the range of 40 to 90 ° C. to a preform composed of a reinforcing fiber substrate disposed in a mold. Inject. Therefore, when the epoxy resin composition of the present invention is a two-pack type, the viscosity within 5 minutes after mixing the main agent and the curing agent is preferably 500 mPa · s or less at 70 ° C., more preferably 300 mPa · s. s or less. In the present invention, the viscosity is measured in accordance with JIS Z8803 (1991) "Viscosity measurement method using a conical-plate rotational viscometer" (E type viscometer equipped with a standard cone rotor (1 ° 34 '× R24) (( Using Tokimec Co., Ltd., TVE-30H), the viscometer is measured at a rotational speed of 50 rpm. If the viscosity within 5 minutes from the start of mixing is higher than the above range, the impregnation property of the epoxy resin composition may be insufficient. The lower limit of the viscosity at 70 ° C. is not particularly limited, and the lower the viscosity, the easier the injection impregnation of the epoxy resin composition of the present invention in the resin transfer molding method.

  Moreover, when the reactivity of the epoxy resin composition of the present invention is high at the injection temperature, the viscosity may increase during the injection process, which may make molding difficult. Therefore, the time for the viscosity of the epoxy resin composition of the present invention to reach 1000 mPa · s at a temperature of 70 ° C. is preferably 60 minutes or more, and more preferably 90 minutes or more. There is no upper limit on the time to reach 1000 mPa · s at a temperature of 70 ° C., and the longer the time, the better the moldability of the fiber-reinforced composite material. The reactivity of the present invention is controlled by defining the amount of component [E] used in the present invention.

  In the present invention, the mold used for the resin transfer molding method may be a rigid closed mold, or a rigid open mold and a flexible film (bag). In the latter case, the fiber substrate made of reinforcing fibers can be placed between the rigid open mold and the flexible film.

  As the rigid material, various kinds of existing materials such as metals such as steel and aluminum, fiber reinforced plastic (FRP), wood and gypsum are used. Nylon, fluorine resin, silicone resin, or the like is used as the material for the flexible film.

  When a rigid closed mold is used, it is usually performed by pressurizing and clamping, and then injecting the epoxy resin composition of the present invention under pressure. At this time, it is also possible to provide a suction port separately from the injection port and connect it to a vacuum pump for suction. It is also possible to inject the epoxy resin composition of the present invention only at atmospheric pressure without performing a suction and using a special pressurizing means.

  In the case of using a rigid open mold and a flexible film, suction and injection by atmospheric pressure are usually used. In order to achieve good impregnation by injection at atmospheric pressure, it is effective to use a resin diffusion medium. Furthermore, it is also preferable to apply a gel coat to a rigid surface prior to the installation of a fiber substrate or preform made of reinforcing fibers.

  After the installation of the fiber base material or preform made of reinforcing fibers is completed, mold clamping or bagging is performed, and then the epoxy resin composition of the present invention is injected, followed by heat curing. The temperature of the mold at the time of heat curing is usually selected to be higher than the temperature of the mold at the time of injection of the epoxy resin composition. The mold temperature during heat curing is preferably 80 to 180 ° C. The time for heat curing is preferably 1 to 20 hours. After the heat curing is completed, the mold is removed and the fiber reinforced composite material is taken out. Thereafter, the obtained fiber-reinforced composite material may be post-cured by heating at a temperature higher than the curing temperature. The post-curing temperature is preferably 150 to 200 ° C., and the time is preferably 1 to 4 hours.

  The fiber-reinforced composite material of the present invention is excellent in adhesiveness between the material constituting the reinforcing fiber and the fiber substrate and the epoxy resin composition of the present invention.

  In order to use the fiber-reinforced composite material of the present invention as an aircraft structural member, the 90-degree tensile strength that is an index of adhesion is preferably 45 to 70 MPa, and more preferably 50 to 65 MPa. In addition, the measurement of 90 degree | times tensile strength of a fiber reinforced composite material is performed according to ASTMD3039. By setting the 90-degree tensile strength to 45 MPa or more, excellent adhesiveness can be obtained, and a fiber-reinforced composite material having excellent compression characteristics can be obtained. On the other hand, when the adhesiveness is increased to 70 MPa or more, the 0-degree tensile strength may decrease.

  The fiber-reinforced composite material of the present invention is light because the volume content of the reinforcing fiber is high, and is excellent in mechanical properties, and in particular, because it has excellent adhesion between the reinforcing fiber and the matrix resin, the fuselage, main wing, tail wing, moving blade, Aircraft members such as fairings, cowls, doors, seats and interior materials, spacecraft members such as motor cases and main wings, artificial satellite members such as structures and antennas, automobile members such as outer panels, chassis, aerodynamic members and seats, structures It can be suitably used for many structural materials such as railway vehicle members such as seats, and ship members such as hulls and seats.

  Hereinafter, the epoxy resin composition of the present invention will be described more specifically with reference to examples. The unit “parts” of the composition ratio means “parts by weight” unless otherwise noted.

<Resin viscosity measurement>
In the epoxy resin compositions obtained in the examples, the respective viscosities of the main agent, the curing agent and the mixture thereof constituting the epoxy resin composition are measured by “cone-plate-type rotational viscometer” in JIS Z8803 (1991). In accordance with “Method”, a viscosity at a predetermined temperature was obtained at a rotation speed of 50 revolutions / minute using an E-type viscometer (TVE-30H, manufactured by Tokimec Co., Ltd.) equipped with a standard cone rotor (1 ° 34 ′ × R24). Was measured.

  The initial viscosity was determined within 5 minutes after mixing the main agent and curing agent of the mixture.

<Method for measuring flexural modulus of cured resin>
The epoxy resin composition obtained in the examples was poured into a predetermined mold, heated in a hot air oven from room temperature to 130 ° C. by 1.5 ° C. per minute, and then at a temperature of 130 ° C. It was held for 2 hours, then heated to 1.5 ° C. per minute to a temperature of 180 ° C., and then held at a temperature of 180 ° C. for 2 hours to produce a 2 mm thick resin cured plate. A test piece having a width of 10 mm and a length of 60 mm was cut out from the produced cured resin plate, a three-point bending test was performed at a test speed of 2.5 mm / min, and a fulcrum distance of 32 mm, and the flexural modulus was measured according to JIS K7171-1994. .

<Method for measuring glass transition temperature of cured resin>
The midpoint glass transition temperature was calculated | required by DSC method for the small piece (5-10 mg) of the obtained resin hardening board according to JISK7121-1987. A Pyris 1 DSC (manufactured by Perkin Elmer) was used as a measuring apparatus, and measurement was performed at a temperature rising rate of 40 ° C./min in a nitrogen gas atmosphere.

<Manufacture of fiber base material 1 made of carbon fiber>

The fiber substrate 1 made of carbon fiber used in each example was produced as follows. PAN-based untwisted carbon fiber bundle “Treca (registered trademark)” T800S-24K-10C (Toray Industries, Inc., 24000 filaments) is used as a warp yarn, and it is aligned at a density of 1.8 yarns / cm and is unidirectional A sheet-like reinforcing fiber bundle group was formed. Glass fibers ECE225 1/0 1Z (manufactured by Nittobo Co., Ltd.) are used as wefts, arranged at a density of 3 strands / cm in a direction perpendicular to the unidirectional sheet-like reinforcing fiber bundle group, and using a loom A woven fabric having a plain weave structure in which the warp and the weft are woven so as to cross each other and the carbon fibers are substantially arranged in one direction is produced. The obtained fiber base material 1 had a carbon fiber basis weight of 190 g / m ² . <Manufacture of fiber base material 2 made of carbon fiber>
The fiber base material 2 made of carbon fiber used in each example was produced as follows. PAN-based untwisted carbon fiber bundle “Torayca (registered trademark)” T800S-24K-10C (manufactured by Toray Industries, Inc., 24000 filaments) is used as a warp and aligned at a density of 1.8 yarns / cm and parallel to this. In addition, glass fiber bundles ECE225 1/0 1Z (manufactured by Nittobo Co., Ltd., 200 filaments) are arranged at a density of 1.8 fibers / cm as auxiliary warp yarns arranged alternately. Groups were formed. Polyamide fiber bundles (polyamide 66, 7 filaments) are used as wefts, arranged at a density of 3 strands / cm in a direction perpendicular to the unidirectional sheet-like reinforcing fiber bundle group, and the auxiliary warp and weft yarns using a loom. Were woven so as to cross each other, and a unidirectional non-crimp woven fabric in which carbon fiber bundles were substantially arranged in one direction and had no crimp was produced as a fiber substrate 2. The carbon fiber basis weight of the fiber base 2 was 192 g / m ² .

<Manufacture of fiber substrate with binder>
60 parts of polyethersulfone “Sumika Excel (registered trademark)” 5003P (manufactured by Sumitomo Chemical Co., Ltd.), 23.5 parts of bisphenol F type epoxy resin “Epicoat (registered trademark)” (manufactured by Japan Epoxy Resin Co., Ltd.), 12.5 parts of biphenyl aralkyl epoxy resin NC-3000 (manufactured by Nippon Kayaku Co., Ltd.) and 4 parts of triglycidyl isocyanurate TEPIC-P (manufactured by Nissan Chemical Industries, Ltd.) at 210 ° C. with a twin screw extruder After melt-kneading, the resulting composition was classified after freezing and pulverization to obtain binder particles having a volume average particle diameter of 100 μm and a glass transition temperature of 73 ° C. The volume average particle diameter is measured according to JIS K5600-9-3 (2006) using a laser diffraction / scattering type particle size distribution analyzer (LMS-24, manufactured by Seishin Enterprise Co., Ltd.), and the glass transition temperature is It measured similarly to the measuring method of the glass transition temperature of an above described resin cured material.

  The obtained binder particles are spontaneously dropped onto one side surfaces of the fiber base material 1 and the fiber base material 2 while being measured with an embossing roll and a doctor blade, and uniformly dispersed through a vibration net. It sprayed so that it might become / m2. Thereafter, a far-infrared heater was passed under conditions of 200 ° C. and 0.3 m / min, and the binder was fused to the entire surface of one side of the fiber substrate to obtain fiber substrates 1 and 2 with a binder.

<Manufacture of specimens of fiber reinforced composite materials>
The fiber reinforced composite material used in each example was produced by a resin transfer molding method. The longitudinal direction of the carbon fibers of the fiber base materials 1 and 2 obtained above was set to 0 degree, and 12 sheets were laminated in the same orientation direction to prepare a preform. The resulting preform was injected and impregnated with the epoxy resin composition obtained in each example at a temperature of 70 ° C., then heated to 130 ° C. at a rate of 1.5 ° C. per minute. Pre-cure for 2 hours at temperature. After removing the pre-cured product from the mold, it is heated to 180 ° C. in a hot air oven at a rate of 1.5 ° C. per minute and cured at a temperature of 180 ° C. for 2 hours. It was.

<Measurement of 90 degree tensile strength of fiber reinforced composite material>
From the fiber-reinforced composite material obtained by the above-described production method, a short test piece having a length of 190 mm and a width of 25.4 mm was cut out with the longitudinal direction of the test piece being a carbon fiber orientation angle of 90 degrees, and measured according to ASTM D3039. The number of samples was 5.

<Example 1>
An epoxy resin composition was obtained according to the following formulation. In addition, the obtained epoxy resin composition was a two-component form, and used the main ingredient and the hardening | curing agent mixed before use.
"Main agent"
"Araldite (registered trademark)" MY721 (tetraglycidyldiaminodiphenylmethane, molecular weight: 450, manufactured by Huntsman Advanced Materials): 61 parts GAN (N, N-diglycidylaniline, molecular weight: 205, Nippon Kayaku Kogyo ( 10 parts) "Denacol (registered trademark)" EX-830 (polyethylene glycol diglycidyl ether, n = 9, molecular weight: 536, Nagase ChemteX Corporation): 5 parts, "Kaneace (registered trademark) "MX416 (" Araldite "MY721: 75 parts / core-shell polymer (volume average particle size: 100 nm, core component: crosslinked polybutadiene (glass transition temperature: -70 ° C), shell: PMMA / glycidyl methacrylate / styrene copolymer): 25) Part masterbatch): 32 parts "curing agent"
"JER Cure (registered trademark)" W (diethyltoluenediamine, manufactured by Japan Epoxy Resins Co., Ltd.): 34.0 parts-3,3'-DAS (3,3'-diaminodiphenylsulfone, Konishi Chemical Industries, Ltd. )): 6.0 parts · TBC (t-butylcatechol, manufactured by Dainippon Ink & Chemicals, Inc.): 0.5 parts.

  As a result of measuring the viscosity of the obtained epoxy resin composition by the above-mentioned method, the viscosity of the main agent at 70 ° C. is 320 mPa · s, and the viscosity of the curing agent at 70 ° C. is 80 mPa · s. The initial viscosity at 70 ° C. of the mixture obtained by mixing 40.5 parts of the curing agent was 223 mPa · s, and the time to reach 1000 mPa · s at a temperature of 70 ° C. was 210 minutes.

  Using the obtained mixture, a cured resin was prepared by the above-described method, and the glass transition temperature was measured. As a result, the flexural modulus at 195 ° C. and 25 ° C. was 3.7 GPa, and was prepared by resin transfer molding. Suitable for matrix resin of fiber reinforced composite material.

  The obtained epoxy resin composition was used for the fiber base material 1 without a binder as described above, and a fiber reinforced composite material was prepared by the method described above, and the 90-degree tensile strength was measured. Suitable for parts.

<Example 2>
Using the fiber base material 2 having no binder as described above for the two-pack type epoxy resin composition obtained in Example 1, a fiber-reinforced composite material was prepared by the above method, and the 90-degree tensile strength was measured. It was a high value of 47 MPa and was suitable for a structural member.

<Example 3>
A two-pack type epoxy resin composition was obtained in the same manner as in Example 1 with the following formulation.
"Main agent"
"Araldite (registered trademark)" MY721 (tetraglycidyldiaminodiphenylmethane, molecular weight: 450, manufactured by Huntsman Advanced Materials): 37 parts-GAN (N, N-diglycidylaniline, molecular weight: 205, Nippon Kayaku Kogyo ( Co., Ltd.): 55 parts, “Denacol (registered trademark)” EX-830 (polyethylene glycol diglycidyl ether, n = 9, molecular weight: 536, Nagase ChemteX Corporation): 5 parts, “Kaneace (registered trademark)” "MX416 (" Araldite "MY721: 75 parts / core-shell polymer (volume average particle diameter: 100 nm, core component: crosslinked polybutadiene (glass transition temperature: -70 ° C), shell: PMMA / glycidyl methacrylate / styrene copolymer): 25) Part masterbatch): 4 parts "curing agent"
"JER Cure (registered trademark)" W (diethyltoluenediamine, manufactured by Japan Epoxy Resins Co., Ltd.): 27.9 parts-3,3'-DAS (3,3'-diaminodiphenylsulfone, Konishi Chemical Industries, Ltd.) )): 6.0 parts "Seika Cure (registered trademark)" S (4,4'-diaminodiphenylmethane, manufactured by Seika Co., Ltd.): 6.0 parts TBC (t-butylcatechol, Dainippon Ink & Chemicals, Inc.) Manufactured by): 1.5 parts.

  As a result of measuring the viscosity of the obtained epoxy resin composition by the above method, the viscosity of the main agent at 70 ° C. was 103 mPa · s, and the viscosity of the curing agent at 70 ° C. was 72 mPa · s. The initial viscosity at 70 ° C. of the mixture obtained by mixing 41.4 parts of the curing agent was 95 mPa · s, and the time to reach 1000 mPa · s at a temperature of 70 ° C. was 162 minutes.

  The physical properties of the cured resin were measured in the same manner as in Example 1. As a result, the flexural modulus at a glass transition temperature of 162 ° C. and 25 ° C. was 3.9 GPa, and the fiber reinforced composite material produced by resin transfer molding was used. Suitable for matrix resin.

  Using the obtained epoxy resin composition, a fiber-reinforced composite material was produced in the same manner as in Example 2, and the 90-degree tensile strength was measured. As a result, it was a high value of 47 MPa and was suitable for a structural member.

<Example 4>
A two-pack type epoxy resin composition was obtained in the same manner as in Example 1 with the following formulation.
"Main agent"
"Araldite (registered trademark)" MY721 (tetraglycidyldiaminodiphenylmethane, molecular weight: 450, manufactured by Huntsman Advanced Materials): 41 parts-GAN (N, N-diglycidylaniline, molecular weight: 205, Nippon Kayaku Kogyo ( 40 parts) "Denacol (registered trademark)" EX-830 (polyethylene glycol diglycidyl ether, n = 9, molecular weight: 536, Nagase ChemteX Corporation): 10 parts "Kaneace (registered trademark) "MX416 (" Araldite "MY721: 75 parts / core-shell polymer (volume average particle diameter: 100 nm, core component: crosslinked polybutadiene (glass transition temperature: -70 ° C), shell: PMMA / glycidyl methacrylate / styrene copolymer): 25) Part masterbatch): 12 parts "curing agent
"JER Cure (registered trademark)" W (diethyltoluenediamine, manufactured by Japan Epoxy Resins Co., Ltd.): 27.5 parts-3,3'-DAS (3,3'-diaminodiphenylsulfone, Konishi Chemical Industries, Ltd. )): 5.9 parts "SEICA CURE (registered trademark)" S (4,4'-diaminodiphenylmethane, manufactured by Seika Co., Ltd.): 5.9 parts-TBC (t-butylcatechol, Dainippon Ink & Chemicals, Inc.) Manufactured by): 1.5 parts.

  As a result of measuring the viscosity of the obtained epoxy resin composition by the above-mentioned method, the viscosity of the main agent at 70 ° C. is 105 mPa · s, and the viscosity of the curing agent at 70 ° C. is 70 mPa · s. The initial viscosity at 70 ° C. of the mixture obtained by mixing 40.8 parts of the curing agent was 83 mPa · s, and the time to reach 1000 mPa · s at a temperature of 70 ° C. was 165 minutes.

  The physical properties of the cured resin were measured in the same manner as in Example 1. As a result, the flexural modulus at a glass transition temperature of 174 ° C. and 25 ° C. was 3.4 GPa, and the fiber-reinforced composite material produced by resin transfer molding was used. Suitable for matrix resin.

  Using the obtained epoxy resin composition, a fiber-reinforced composite material was produced in the same manner as in Example 2, and the 90-degree tensile strength was measured. As a result, it was a high value of 52 MPa, and was suitable for a structural member.

<Example 5>
A two-pack type epoxy resin composition was obtained in the same manner as in Example 1 with the following formulation.
"Main agent"
"Araldite (registered trademark)" MY721 (tetraglycidyl diaminodiphenylmethane, molecular weight: 450, manufactured by Huntsman Advanced Materials): 16 parts "jER (registered trademark)" 630 (N, N, O-triglycidyl-p -Aminophenol, molecular weight: 277, manufactured by Japan Epoxy Resin Co., Ltd.): 25 parts GAN (N, N-diglycidylaniline, molecular weight: 205, manufactured by Nippon Kayaku Co., Ltd.): 40 parts "Denacol ( (Registered trademark) "EX-830 (polyethylene glycol diglycidyl ether, n = 9, molecular weight: 536, Nagase ChemteX Corporation): 10 parts""Kaneace (registered trademark)" MX416 ("Araldite" MY721: 75 parts / Core-shell polymer (volume average particle diameter: 100 nm, core component: crosslinked polybutadiene) Down (glass transition temperature: -70 ° C.), the shell: PMMA / glycidyl methacrylate / styrene copolymer): 25 parts of the masterbatch): 12 parts of "curing agent"
"JER Cure (registered trademark)" W (diethyltoluenediamine, manufactured by Japan Epoxy Resin Co., Ltd.): 28.7 parts-3,3'-DAS (3,3'-diaminodiphenylsulfone, Konishi Chemical Industries, Ltd.) )): 8.2 parts "SEICA CURE (registered trademark)" S (4,4'-diaminodiphenylmethane, manufactured by Seika Co., Ltd.): 4.1 parts TBC (t-butylcatechol, Dainippon Ink & Chemicals, Inc.) (Made by Co., Ltd.): 3.0 parts.

  As a result of measuring the viscosity of the obtained epoxy resin composition by the above-described method, the viscosity of the main agent at 70 ° C. is 96 mPa · s, and the viscosity of the curing agent at 70 ° C. is 73 mPa · s. The initial viscosity at 70 ° C. of the mixture obtained by mixing 44.0 parts of the curing agent was 90 mPa · s, and the time to reach 1000 mPa · s at a temperature of 70 ° C. was 120 minutes.

  The physical properties of the cured resin were measured in the same manner as in Example 1. As a result, the flexural modulus at a glass transition temperature of 172 ° C. and 25 ° C. was 3.5 GPa, and the fiber-reinforced composite material produced by resin transfer molding was used. Suitable for matrix resin.

  Using the obtained epoxy resin composition, a fiber reinforced composite material was produced in the same manner as in Example 2, and the 90-degree tensile strength was measured. As a result, the value was as high as 57 MPa, which was suitable for a structural member.

<Example 6>
A two-pack type epoxy resin composition was obtained in the same manner as in Example 1 with the following formulation.
"Main agent"
"JER (registered trademark)" 152 (phenol novolac type epoxy resin, molecular weight: 360, manufactured by Japan Epoxy Resin Co., Ltd.): 16 parts "jER (registered trademark)" 630 (N, N, O-triglycidyl- p-aminophenol, molecular weight: 277, manufactured by Japan Epoxy Resin Co., Ltd.): 25 parts • GAN (N, N-diglycidylaniline, molecular weight: 205, manufactured by Nippon Kayaku Kogyo Co., Ltd.): 40 parts • “Denacol (Registered trademark) "EX-830 (polyethylene glycol diglycidyl ether, n = 9, molecular weight: 536, Nagase ChemteX Corporation): 10 parts" Kaneace (registered trademark) "MX416 (" Araldite "MY721: 75 parts) / Core-shell polymer (volume average particle diameter: 100 nm, core component: crosslinked polybutadiene (glass transition temperature: -7 ° C.), the shell: PMMA / glycidyl methacrylate / styrene copolymer): 25 parts of the masterbatch): 12 parts of "curing agent"
"JER Cure (registered trademark)" W (diethyltoluenediamine, manufactured by Japan Epoxy Resins Co., Ltd.): 26.9 parts3,3'-DAS (3,3'-diaminodiphenylsulfone, Konishi Chemical Industries, Ltd. )): 7.7 parts "SEICA CURE (registered trademark)" S (4,4'-diaminodiphenylmethane, manufactured by Seika Co., Ltd.): 3.8 parts TBC (t-butylcatechol, Dainippon Ink & Chemicals, Inc.) (Made by Co., Ltd.): 3.0 parts.

  As a result of measuring the viscosity of the obtained epoxy resin composition by the above-described method, the viscosity of the main agent at 70 ° C. is 90 mPa · s, and the viscosity of the curing agent at 70 ° C. is 73 mPa · s. The initial viscosity at 70 ° C. of the mixture obtained by mixing 41.5 parts of the curing agent was 78 mPa · s, and the time to reach 1000 mPa · s at a temperature of 70 ° C. was 118 minutes.

  The physical properties of the cured resin were measured in the same manner as in Example 1. As a result, the flexural modulus at a glass transition temperature of 165 ° C. and 25 ° C. was 3.4 GPa, and the fiber-reinforced composite material produced by resin transfer molding was used. Suitable for matrix resin.

  Using the obtained epoxy resin composition, a fiber-reinforced composite material was produced in the same manner as in Example 2, and the 90-degree tensile strength was measured. As a result, the value was as high as 50 MPa, which was suitable for a structural member.

<Example 7>
A two-pack type epoxy resin composition was obtained in the same manner as in Example 1 with the following formulation.
"Main agent"
"JER (registered trademark)" 152 (phenol novolac type epoxy resin, molecular weight: 360, manufactured by Japan Epoxy Resins Co., Ltd.): 21 parts-"jER (registered trademark)" 630 (N, N, O-triglycidyl- p-aminophenol, molecular weight: 277, manufactured by Japan Epoxy Resins Co., Ltd.): 30 parts • GAN (N, N-diglycidylaniline, molecular weight: 205, manufactured by Nippon Kayaku Kogyo Co., Ltd.): 20 parts “Denacol (Registered trademark) "EX-830 (polyethylene glycol diglycidyl ether, n = 9, molecular weight: 536, Nagase ChemteX Corporation): 20 parts" Kaneace (registered trademark) "MX416 (" Araldite "MY721: 75 parts) / Core-shell polymer (volume average particle diameter: 100 nm, core component: crosslinked polybutadiene (glass transition temperature: -7 ° C.), the shell: PMMA / glycidyl methacrylate / styrene copolymer): 25 parts of the masterbatch): 12 parts of "curing agent"
"JER Cure (registered trademark)" W (diethyltoluenediamine, manufactured by Japan Epoxy Resins Co., Ltd.): 25.5 parts-3,3'-DAS (3,3'-diaminodiphenylsulfone, Konishi Chemical Industries, Ltd.) )): 7.3 parts "Seika Cure (registered trademark)" S (4,4'-diaminodiphenylmethane, manufactured by Seika Co., Ltd.): 3.6 parts TBC (t-butylcatechol, Dainippon Ink & Chemicals, Inc.) (Made by Co., Ltd.): 3.0 parts.

  As a result of measuring the viscosity of the obtained epoxy resin composition by the above-mentioned method, the viscosity of the main agent at 70 ° C. is 82 mPa · s, and the viscosity of the curing agent at 70 ° C. is 74 mPa · s. The initial viscosity at 70 ° C. of the mixture obtained by mixing 39.4 parts of the curing agent was 75 mPa · s, and the time to reach 1000 mPa · s at a temperature of 70 ° C. was 118 minutes.

  Using the obtained mixture, a cured resin product was prepared by the above-described method, and the glass transition temperature was measured. As a result, the flexural modulus at a glass transition temperature of 142 ° C. and 25 ° C. was 2.8 GPa.

  Using the obtained epoxy resin composition, a fiber-reinforced composite material was produced in the same manner as in Example 2, and the 90-degree tensile strength was measured. As a result, the value was as high as 53 MPa.

<Example 8>
A two-pack type epoxy resin composition was obtained in the same manner as in Example 1 with the following formulation.
"Main agent"
"Araldite (registered trademark)" MY721 (tetraglycidyldiaminodiphenylmethane, molecular weight: 450, manufactured by Huntsman Advanced Materials): 41 parts-GOT (N, N-diglycidyl-O-toluidine, molecular weight: 219, Nippon Kayaku) Industrial Co., Ltd.): 40 parts, “Denacol (registered trademark)” EX-830 (polyethylene glycol diglycidyl ether, n = 9, molecular weight: 536, Nagase ChemteX Corporation): 10 parts, “Kaneace (registered) Trademark) "MX416 (" Araldite "MY721: 75 parts / core-shell polymer (volume average particle size: 100 nm, core component: crosslinked polybutadiene (glass transition temperature: -70 ° C), shell: PMMA / glycidyl methacrylate / styrene copolymer)) : 25 parts masterbatch): 12 parts Curing agent "
"JER Cure (registered trademark)" W (diethyltoluenediamine, manufactured by Japan Epoxy Resin Co., Ltd.): 26.7 parts-3,3'-DAS (3,3'-diaminodiphenylsulfone, Konishi Chemical Industries, Ltd.) )): 5.7 parts "SEICA CURE (registered trademark)" S (4,4'-diaminodiphenylmethane, manufactured by Seika Co., Ltd.): 5.7 parts-TBC (t-butylcatechol, Dainippon Ink & Chemicals, Inc.) Manufactured by): 1.5 parts.

  As a result of measuring the viscosity of the obtained epoxy resin composition by the above-mentioned method, the viscosity of the main agent at 70 ° C. is 102 mPa · s, and the viscosity of the curing agent at 70 ° C. is 72 mPa · s. The initial viscosity at 70 ° C. of the mixture obtained by mixing 39.6 parts of the curing agent was 86 mPa · s, and the time to reach 1000 mPa · s at a temperature of 70 ° C. was 160 minutes.

  The physical properties of the cured resin were measured in the same manner as in Example 1. As a result, the flexural modulus at a glass transition temperature of 168 ° C. and 25 ° C. was 3.4 GPa, and the fiber-reinforced composite material produced by resin transfer molding was used. Suitable for matrix resin.

  Using the obtained epoxy resin composition, a fiber reinforced composite material was produced in the same manner as in Example 2, and the 90-degree tensile strength was measured. As a result, the value was as high as 55 MPa, which was suitable for a structural member.

<Example 9>
A two-pack type epoxy resin composition was obtained in the same manner as in Example 1 with the following formulation.
"Main agent"
"Araldite (registered trademark)" MY721 (tetraglycidyldiaminodiphenylmethane, molecular weight: 450, manufactured by Huntsman Advanced Materials): 31 parts GOT (N, N-diglycidyl-O-toluidine, molecular weight: 219, Nippon Kayaku) Industrial Co., Ltd.): 40 parts, “Denacol (registered trademark)” EX-830 (polyethylene glycol diglycidyl ether, n = 9, molecular weight: 536, Nagase ChemteX Corporation): 5 parts, “Kane Ace (registered) Trademark) "MX416 (" Araldite "MY721: 75 parts / core-shell polymer (volume average particle size: 100 nm, core component: crosslinked polybutadiene (glass transition temperature: -70 ° C), shell: PMMA / glycidyl methacrylate / styrene copolymer)) : 25 parts masterbatch): 12 parts EPON (registered trademark) "825 (bisphenol A type epoxy resin, molecular weight: 380, manufactured by Japan Epoxy Resins Co.): 15 parts of" curing agent "
"JER Cure (registered trademark)" W (diethyltoluenediamine, manufactured by Japan Epoxy Resin Co., Ltd.): 25.9 parts 3,3'-DAS (3,3'-diaminodiphenylsulfone, Konishi Chemical Industries, Ltd.) )): 5.6 parts "Seikacure (registered trademark)" S (4,4'-diaminodiphenylmethane, manufactured by Seika Co., Ltd.): 5.6 parts-TBC (t-butylcatechol, Dainippon Ink & Chemicals, Inc.) Manufactured by): 1.5 parts.

  As a result of measuring the viscosity of the obtained epoxy resin composition by the above-described method, the viscosity of the main agent at 70 ° C. is 105 mPa · s, and the viscosity of the curing agent at 70 ° C. is 72 mPa · s. The initial viscosity at 70 ° C. of the mixture obtained by mixing 38.6 parts of the curing agent was 93 mPa · s, and the time to reach 1000 mPa · s at a temperature of 70 ° C. was 162 minutes.

  The physical properties of the cured resin were measured in the same manner as in Example 1. As a result, the flexural modulus at a glass transition temperature of 175 ° C. and 25 ° C. was 3.3 GPa, and the fiber-reinforced composite material produced by resin transfer molding was used. Suitable for matrix resin.

  As a result of producing a fiber-reinforced composite material by the above-described method using the above-mentioned fiber base material 1 with a binder and measuring the 90-degree tensile strength, the obtained epoxy resin composition has a high value of 49 MPa, and the structure Suitable for parts.

<Example 10>
A fiber reinforced composite material was produced by the above-described method using the above-described binder-attached fiber base material 2 obtained from the two-pack type epoxy resin composition obtained in Example 9, and the result of measuring the 90-degree tensile strength was 52 MPa. It was a high value and suitable for structural members.

<Example 11>
A two-pack type epoxy resin composition was obtained in the same manner as in Example 1 with the following formulation.
"Main agent"
"Araldite (registered trademark)" MY721 (tetraglycidyldiaminodiphenylmethane, molecular weight: 450, manufactured by Huntsman Advanced Materials): 26 parts-GOT (N, N-diglycidyl-O-toluidine, molecular weight: 219, Nippon Kayaku) Industrial Co., Ltd.): 25 parts, “Denacol (registered trademark)” EX-830 (polyethylene glycol diglycidyl ether, n = 9, molecular weight: 536, Nagase ChemteX Corporation): 10 parts, “Kaneace (registered) Trademark) "MX416 (" Araldite "MY721: 75 parts / core-shell polymer (volume average particle size: 100 nm, core component: crosslinked polybutadiene (glass transition temperature: -70 ° C), shell: PMMA / glycidyl methacrylate / styrene copolymer)) : 25 parts masterbatch): 32 parts "EPON (registered trademark)" 825 (bisphenol A type epoxy resin, molecular weight: 380, manufactured by Japan Epoxy Resins Co.): 15 parts of "curing agent"
"JER Cure (registered trademark)" W (diethyltoluenediamine, manufactured by Japan Epoxy Resin Co., Ltd.): 25.8 parts3,3'-DAS (3,3'-diaminodiphenylsulfone, Konishi Chemical Industries, Ltd.) )): 5.5 parts "Seika Cure (registered trademark)" S (4,4'-diaminodiphenylmethane, manufactured by Seika Co., Ltd.): 5.5 parts TBC (t-butylcatechol, Dainippon Ink & Chemicals, Inc.) Manufactured by): 1.5 parts.

  As a result of measuring the viscosity of the obtained epoxy resin composition by the above-mentioned method, the viscosity of the main agent at 70 ° C. is 119 mPa · s, and the viscosity of the curing agent at 70 ° C. is 71 mPa · s. The initial viscosity at 70 ° C. of the mixture obtained by mixing 38.3 parts of the curing agent was 105 mPa · s, and the time to reach 1000 mPa · s at a temperature of 70 ° C. was 157 minutes.

  The physical properties of the cured resin were measured in the same manner as in Example 1. As a result, the flexural modulus at a glass transition temperature of 170 ° C. and 25 ° C. was 3.1 GPa, and the fiber reinforced composite material produced by resin transfer molding was used. Suitable for matrix resin.

  Using the obtained epoxy resin composition, a fiber-reinforced composite material was produced in the same manner as in Example 10, and the 90-degree tensile strength was measured. As a result, it was a high value of 60 MPa, and was suitable for a structural member.

<Comparative Example 1>
An epoxy resin composition was obtained according to the following formulation. In addition, the obtained epoxy resin composition was a two-component form, and used the main ingredient and the hardening | curing agent mixed before use.
"Main agent"
"Araldite (registered trademark)" MY721 (tetraglycidyldiaminodiphenylmethane, molecular weight: 450, manufactured by Huntsman Advanced Materials): 85 parts-GAN (N, N-diglycidylaniline, molecular weight: 205, Nippon Kayaku Kogyo ( Co., Ltd.): 15 parts "curing agent"
"JER Cure (registered trademark)" W (diethyltoluenediamine, manufactured by Japan Epoxy Resins Co., Ltd.): 34.6 parts3,3'-DAS (3,3'-diaminodiphenylsulfone, Konishi Chemical Industries, Ltd. )): 6.1 parts · TBC (t-butylcatechol, manufactured by Dainippon Ink & Chemicals, Inc.): 0.5 parts.

  As a result of measuring the viscosity of the obtained epoxy resin composition by the above-described method, the viscosity of the main agent at 70 ° C. is 323 mPa · s, and the viscosity of the curing agent at 70 ° C. is 80 Pa · s. The initial viscosity at 70 ° C. of the mixture obtained by mixing 41.2 parts of the curing agent was 234 mPa · s, and the time to reach 1000 mPa · s at a temperature of 70 ° C. was 215 minutes.

  Using the obtained mixture, a cured resin was prepared by the above-described method, and the physical properties of the cured resin were measured. As a result, the flexural modulus at a glass transition temperature of 210 ° C. and 25 ° C. was 4.2 GPa. It was suitable as a matrix resin for fiber-reinforced composite materials produced by transfer molding.

  Using the obtained epoxy resin composition, a fiber reinforced composite material was produced using the above-described fiber base 1 without a binder, and the 90-degree tensile strength was measured. It was inappropriate.

<Comparative example 2>
As a result of producing a fiber reinforced composite material by the above method using the above-described fiber base material 2 without a binder, the two-pack type epoxy resin composition obtained in Comparative Example 1, and measuring the tensile strength at 90 degrees, The value was as low as 37 MPa, which was unsuitable for structural members.

<Comparative Example 3>
A two-pack type epoxy resin composition was obtained in the same manner as in Comparative Example 1 by the following formulation.
"Main agent"
"Araldite (registered trademark)" MY721 (tetraglycidyldiaminodiphenylmethane, molecular weight: 450, manufactured by Huntsman Advanced Materials): 31 parts GOT (N, N-diglycidyl-O-toluidine, molecular weight: 219, Nippon Kayaku) Industrial Co., Ltd.): 40 parts SR-NPG (Neopentyl glycol diglycidyl ether, molecular weight: 216, Sakamoto Yakuhin Kogyo Co., Ltd.): 5 parts “Kane Ace (registered trademark)” MX416 (“Araldite” MY721: 75 parts / core-shell polymer (volume average particle diameter: 100 nm, core component: crosslinked polybutadiene (glass transition temperature: -70 ° C.), shell: PMMA / glycidyl methacrylate / styrene copolymer): 25 parts masterbatch): 12 parts "EPON (registered trademark)" 825 (Bisfe Lumpur A type epoxy resin, molecular weight: 380, manufactured by Japan Epoxy Resins Co.): 15 parts of "curing agent"
"JER Cure (registered trademark)" W (diethyltoluenediamine, manufactured by Japan Epoxy Resin Co., Ltd.): 26.6 parts3,3'-DAS (3,3'-diaminodiphenylsulfone, Konishi Chemical Industries, Ltd. )): 5.7 parts "SEICA CURE (registered trademark)" S (4,4'-diaminodiphenylmethane, manufactured by Seika Co., Ltd.): 5.7 parts-TBC (t-butylcatechol, Dainippon Ink & Chemicals, Inc.) Manufactured by): 1.5 parts.

  As a result of measuring the viscosity of the obtained epoxy resin composition by the above-described method, the viscosity of the main agent at 70 ° C. is 103 mPa · s, and the viscosity of the curing agent at 70 ° C. is 72 mPa · s. The initial viscosity at 70 ° C. of the mixture obtained by mixing 39.5 parts of the curing agent was 94 mPa · s, and the time to reach 1000 mPa · s at a temperature of 70 ° C. was 163 minutes.

  As a result of measuring physical properties of the cured resin as in Comparative Example 1, the flexural modulus at a glass transition temperature of 178 ° C. and 25 ° C. is 3.2 GPa, and the fiber-reinforced composite material produced by resin transfer molding is used. Suitable for matrix resin.

  Using the obtained epoxy resin composition, a fiber-reinforced composite material was prepared by the above-described method using the above-described fiber substrate 1 with a binder, and the tensile strength at 90 degrees was measured. As a result, it was a low value of 37 MPa. It was unsuitable for structural members.

<Comparative example 4>
As a result of producing a fiber reinforced composite material by the above-described method using the above-mentioned fiber base material 2 with a binder obtained from the two-component epoxy resin composition obtained in Comparative Example 3, and measuring the 90-degree tensile strength, 37 MPa It was a low value and unsuitable for structural members.

<Comparative Example 5>
A two-pack type epoxy resin composition was obtained in the same manner as in Comparative Example 1 by the following formulation.
"Main agent"
"Araldite (registered trademark)" MY721 (tetraglycidyldiaminodiphenylmethane, molecular weight: 450, manufactured by Huntsman Advanced Materials): 26 parts-GOT (N, N-diglycidyl-O-toluidine, molecular weight: 219, Nippon Kayaku) Industrial Co., Ltd.): 40 parts "Denacol (registered trademark)" EX-821 (polyethylene glycol diglycidyl ether, n = 4, molecular weight: 370, Nagase ChemteX Corporation): 10 parts-"Kaneace (registered) Trademark) "MX416 (" Araldite "MY721: 75 parts / core-shell polymer (volume average particle size: 100 nm, core component: crosslinked polybutadiene (glass transition temperature: -70 ° C), shell: PMMA / glycidyl methacrylate / styrene copolymer)) : 25 parts masterbatch): 12 parts "EPON (registered trademark)" 825 (bisphenol A type epoxy resin, molecular weight: 380, manufactured by Japan Epoxy Resins Co.): 15 parts of "curing agent"
"JER Cure (registered trademark)" W (diethyltoluenediamine, manufactured by Japan Epoxy Resins Co., Ltd.): 25.6 parts3,3'-DAS (3,3'-diaminodiphenylsulfone, Konishi Chemical Industries, Ltd.) )): 5.5 parts "Seika Cure (registered trademark)" S (4,4'-diaminodiphenylmethane, manufactured by Seika Co., Ltd.): 5.5 parts TBC (t-butylcatechol, Dainippon Ink & Chemicals, Inc.) Manufactured by): 1.5 parts.

  As a result of measuring the viscosity of the obtained epoxy resin composition by the above-mentioned method, the viscosity of the main agent at 70 ° C. is 120 mPa · s, and the viscosity of the curing agent at 70 ° C. is 72 mPa · s. The initial viscosity at 70 ° C. of the mixture obtained by mixing 38.1 parts of the curing agent was 105 mPa · s, and the time to reach 1000 mPa · s at a temperature of 70 ° C. was 157 minutes.

  As a result of measuring the physical properties of the cured resin as in Comparative Example 1, the flexural modulus at a glass transition temperature of 171 ° C. and 25 ° C. is 3.0 GPa, and the fiber-reinforced composite material produced by resin transfer molding is used. Suitable for matrix resin.

  Using the obtained epoxy resin composition, a fiber reinforced composite material was produced in the same manner as in Comparative Example 4, and the 90-degree tensile strength was measured. As a result, it was a low value of 41 MPa, which was not suitable for a structural member.

Claims (10)

An epoxy resin composition comprising at least the following components [A], [B], [C], [D] and [E].
[A] Epoxy resin having three or more epoxy groups in one molecule [B] Epoxy resin having one diglycidylaniline skeleton in one molecule and two epoxy groups [C] The number of repeating units n is Polyethylene glycol diglycidyl ether [D] which is 5 or more Liquid aromatic diamine [E] core-shell polymer particles whose viscosity at 70 ° C. is 500 mPa · s or less The epoxy resin composition according to claim 1, wherein 10 to 40 parts by weight of diaminodiphenyl sulfone is blended in 100 parts by weight of the wholly aromatic diamine in the component [D]. The epoxy resin composition according to claim 2, wherein the diaminodiphenyl sulfone blended in the component [D] is a combination of 3,3'-diaminodiphenyl sulfone and 4,4'-diaminodiphenyl sulfone. The epoxy resin composition in any one of Claims 1-3 in which 0.5-3 weight part of hardening accelerators are mix | blended with respect to 100 weight part of all the epoxy resins in component [D]. The epoxy resin composition of Claim 4 whose hardening accelerator mix | blended with component [D] is t-butylcatechol. The epoxy resin composition according to any one of claims 1 to 5, wherein, at 70 ° C, the viscosity within 5 minutes from the start of measurement is 500 mPa · s or less, and the time until the viscosity reaches 1000 mPa · s is 60 minutes or more. object. The main component containing at least the following constituent elements [A], [B], [C] and [E] and having a viscosity at 70 ° C. of 500 mPa · s or less, and at least the following constituent element [D], including 70 ° C. The manufacturing method of the two-pack type epoxy resin composition including the process of mixing the hardening | curing agent whose viscosity in 500 mPa * s or less.
[A] Epoxy resin having three or more epoxy groups in one molecule [B] Epoxy resin having one diglycidylaniline skeleton in one molecule and two epoxy groups [C] The number of repeating units n is Polyethylene glycol diglycidyl ether [D] which is 5 or more Liquid aromatic diamine [E] core-shell polymer particles whose viscosity at 70 ° C. is 500 mPa · s or less A fiber-reinforced composite material comprising at least the epoxy resin composition according to any one of claims 1 to 6 or a cured product of the two-component epoxy resin composition produced by the method according to claim 7 and carbon fibers. . The fiber base material having the carbon fiber is arranged so that the warp made of the carbon fiber strand and the auxiliary warp of the fiber bundle made of glass fiber or chemical fiber arranged in parallel to the carbon fiber are orthogonal to these. A non-crimp woven fabric comprising a weft made of glass fiber or chemical fiber, wherein the auxiliary warp and the weft intersect each other, whereby carbon fiber strands are held together to form a woven fabric. Item 9. A fiber-reinforced composite material according to Item 8. It consists of a warp composed of carbon fiber strands, an auxiliary warp of a fiber bundle composed of glass fibers or chemical fibers arranged parallel thereto, and a weft composed of glass fibers or chemical fibers arranged so as to be orthogonal thereto, The non-crimp fabric in which the carbon fiber strands are integrally held and the fabric is formed by the auxiliary warp and the weft intersecting each other is disposed in the mold, and A method for producing a fiber-reinforced composite material, wherein the epoxy resin composition or the two-component epoxy resin composition produced by the method according to claim 7 is injected and impregnated, and then cured by heating.