JP2023088244A - Composition for fiber sizing, and resin-impregnated fiber using the same, and molding - Google Patents

Abstract

To provide a composition for fiber sizing for obtaining a fiber-reinforced thermoplastic resin composite material having excellent mechanical properties such as flexural strength.SOLUTION: A composition for fiber sizing comprises a thermoplastic resin emulsion, and at least one of an acetylene glycol-based nonionic surfactant and a dialkylsulfosuccinate-based anion surfactant. The composition for fiber sizing has a dynamic surface tension of 25-55 mN/m.SELECTED DRAWING: None

Description

The present invention relates to a fiber bundling composition mainly used in the production of fiber-reinforced thermoplastic resin composites, resin-impregnated fibers bundled with the bundling composition, and molded articles using the same.

Fiber materials, typified by carbon fiber, have excellent characteristics such as high strength, high elasticity, and electrical conductivity. It is widely used in various industrial fields such as machinery and sporting goods.

In the production of these fiber-reinforced thermoplastic resin composite materials, the fibers are subjected to a bundling treatment to form a fiber strand, and then (1) a method of making it into short fibers and melt-kneading with a thermoplastic resin, (2) a method of forming a sheet and heating it. It is carried out by lamination with a plastic resin sheet.

The bundling process integrates several hundred to tens of thousands of independent fibers with a bundling agent to form a strand, and is an essential process for the subsequent step of combining with a thermoplastic resin.

This sizing agent not only imparts abrasion resistance to the fiber strands and affects workability in the composite process, but also wettability and adhesiveness between the essentially incompatible fibers and the thermoplastic resin. etc., and is important because it greatly affects the performance and quality of the final fiber-reinforced thermoplastic resin composite material.

Conventionally, various sizing agents have been studied for the purpose of increasing the affinity between fibers and thermoplastic resins. For example, in Patent Document 1, by bundling fibers with an aqueous emulsion containing a copolymerized nylon resin as a main component, the adhesiveness between the fibers and the thermoplastic resin is improved, and the strength of the fiber-reinforced thermoplastic resin composite material is increased. A method of improvement is disclosed. Alternatively, Patent Literature 2 discloses a method of performing a focusing treatment with a styrene emulsion having a specific carboxyl group content.

Further, in Patent Document 3, a continuous reinforcing fiber sheet made of carbon fiber or the like and a resin sheet made of a thermoplastic resin are alternately laminated, and a heat press treatment (heating and pressurizing treatment) is performed to continuously strengthen the sheet. A fiber-reinforced thermoplastic resin composite material is disclosed in which interstices between fibers are impregnated with a thermoplastic resin.

Furthermore, Patent Document 4 proposes a fiber-reinforced thermoplastic resin composite material formed by laminating sheet-like prepregs impregnated with a thermoplastic resin in the gaps between continuous reinforcing fibers made of carbon fibers or the like. The reinforcing fibers of the pre-preg are pre-cut into a predetermined shape (length) and oriented in a predetermined direction, and then adhered (melt-bonded) by a hot press and laminated to achieve excellent productivity and high performance. It is disclosed that it is possible to obtain a fiber reinforced thermoplastic resin composite material having

JP-A-61-254629 JP 2004-176227 A JP 2013-189634 A International publication WO2016/067711

However, although these methods improve the interfacial adhesive strength between the fiber and the thermoplastic resin, the mechanical properties such as bending strength of the finally obtained fiber-reinforced thermoplastic resin composite material are still unsatisfactory. .

In view of the above-mentioned circumstances, the present inventors have made intensive studies to solve the current problems. The inventors have found that the above problems can be solved by having dynamic surface tension, and have completed the present invention.

That is, the present invention consists of the following [1].
[1] A fiber bundling composition containing a thermoplastic resin emulsion and at least one of an acetylene glycol-based nonionic surfactant and a dialkylsulfosuccinate-based anionic surfactant, and having a dynamic surface tension of 25 to A composition for fiber bundling, characterized in that it is 55 mN/m.

The present invention also includes aspects such as the following [2] to [4].
[2] The thermoplastic resin emulsion contains 40 to 98.5% by weight of an aromatic vinyl monomer and 1.5 to 60% by weight of another monomer copolymerizable with the aromatic vinyl monomer. % of the fiber bundling composition according to [1].
[3] Resin-impregnated fibers bundled with the composition for fiber bundling according to either [1] or [2].
[4] A molded article obtained by molding a laminate comprising a layer made of the resin-impregnated fiber according to [3] and a thermoplastic resin layer.

An object of the present invention is to provide a fiber bundling composition capable of improving the bending strength of a molded article, and a resin-impregnated fiber and molded article using the composition.

The present invention will be described in detail below.

The fiber bundling composition of the present invention contains a thermoplastic resin emulsion and at least one of an acetylene glycol-based nonionic surfactant and a dialkylsulfosuccinate-based anionic surfactant.

The thermoplastic resin emulsion contained in the fiber bundling composition of the present invention is not particularly limited as long as it is an aqueous dispersion of a thermoplastic resin. Examples include vinylidene resin emulsions, polyamide resin emulsions, aromatic vinyl resin emulsions, acrylic resin emulsions, and olefin resin emulsions. Among them, an aromatic vinyl-based resin emulsion is preferable from the viewpoint of adhesiveness between the resin-impregnated fiber and the thermoplastic resin.

The aromatic vinyl resin emulsion contains a copolymer of an aromatic vinyl monomer and another monomer copolymerizable with the aromatic vinyl monomer. Other monomers copolymerizable with aromatic vinyl monomers include ethylenically unsaturated carboxylic acid monomers, vinyl cyanide monomers, alkyl ester monomers, and hydroxyalkyl group-containing monomers. unsaturated monomers, unsaturated carboxylic acid amide-based monomers, vinylpyridine-based monomers, conjugated diene-based monomers, etc., each of which can be used alone or in combination of two or more depending on the purpose. It is possible to

Examples of the aromatic vinyl-based monomer include styrene, α-methylstyrene, vinyltoluene, divinylbenzene, and the like, and one or more of these can be used. Styrene and α-methylstyrene are particularly preferred.

Ethylenically unsaturated carboxylic acid monomers include mono- or dicarboxylic acids (anhydrides) such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid and itaconic acid.

Vinyl cyanide monomers include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-ethylacrylonitrile and the like.

Alkyl ester monomers include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, glycidyl methacrylate, dimethyl fumarate, diethyl fumarate, dimethyl maleate, diethyl malate, dimethyl itaconate, and monomethyl fumarate. , monoethyl fumarate, 2-ethylhexyl acrylate and the like.

Unsaturated monomers containing hydroxyalkyl groups include β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, 3-chloro-2-hydroxypropyl methacrylate, di-(ethylene glycol) maleate, di-(ethylene glycol) itaconate, 2-hydroxyethyl maleate, bis(2-hydroxyethyl) maleate, 2-hydroxyethyl methyl fumarate and the like.

Examples of unsaturated carboxylic acid amide-based monomers include acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, and N,N-dimethylacrylamide.

Vinylpyridine-based monomers include 2-vinylpyridine, 3-vinylpyridine, 4-vinylpyridine, 2-methyl-5-vinylpyridine and the like.

Conjugated diene-based monomers include 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene, substituted linear Conjugated pentadienes, substituted and side chain conjugated hexadienes, and the like.

Among others, other monomers copolymerizable with aromatic vinyl monomers include acrylic acid, methacrylic acid, fumaric acid, itaconic acid, acrylonitrile, methacrylonitrile, methyl methacrylate, butyl acrylate, and β-hydroxyethyl. Preference is given to using acrylates, acrylamides or methacrylamides, 2-vinylpyridine, 1,3-butadiene.

The content of the aromatic vinyl monomer in the total amount of monomers (total monomers) used for producing the thermoplastic resin emulsion is preferably 40 to 98.5% by weight, preferably 45 to 95% by weight. % by weight is more preferred, and 47 to 90% by weight is even more preferred. By adjusting it within this range, the adhesion between the resin-impregnated fiber and the thermoplastic resin tends to be excellent.

The content of the "other monomer copolymerizable with the aromatic vinyl monomer" in all the monomers is preferably 1.5 to 60% by weight, and 5 to 55% by weight. is more preferable, and 10 to 53% by weight is even more preferable. By adjusting it within this range, the adhesion between the resin-impregnated fiber and the thermoplastic resin tends to be excellent.

The preferable composition ratio of each monomer in the aromatic vinyl resin emulsion is 60 to 95% by weight of the aromatic vinyl monomer, 4 to 39% by weight of the vinyl cyanide monomer, and the ethylenically unsaturated carboxylic acid. 1 to 15% by weight of the monomer may be mentioned, and a more preferable composition ratio is 80 to 94% by weight of the aromatic vinyl monomer, 5 to 15% by weight of the vinyl cyanide monomer, and the ethylenically unsaturated carboxylic acid. 1 to 5% by weight of acid monomer may be mentioned.

When the thermoplastic resin emulsion contained in the composition for fiber bundling of the present invention is obtained by emulsion polymerization, known emulsion polymerization methods such as batch addition method, divided addition method, continuous addition method, multistage polymerization method, seed Any of a polymerization method, a power feed polymerization method, and the like may be employed. Among them, the continuous addition method is preferable because of the stability during polymerization and the ease of adjusting the molecular weight.

When the thermoplastic resin emulsion contained in the fiber bundling composition of the present invention is subjected to emulsion polymerization, n-hexylmercaptan, n-octylmercaptan, t-octylmercaptan, n-dodecylmercaptan, t-dodecylmercaptan, n- Alkyl mercaptans such as stearyl mercaptan, xanthogen compounds such as dimethylxanthogen disulfide and diisopropylxanthogen disulfide, thiuram compounds such as tetramethylthiuram disulfide, tetraethylthiuram disulfide, and tetramethylthiuram monosulfide, 2,6-di-t-butyl - Phenolic compounds such as 4-methylphenol and styrenated phenol, allyl compounds such as allyl alcohol, halogenated hydrocarbon compounds such as dichloromethane, dibromomethane and carbon tetrabromide, α-benzyloxystyrene, α-benzyloxyacrylonitrile , vinyl ethers such as α-benzyloxyacrylamide, chain transfer agents such as triphenylethane, pentaphenylethane, acrolein, methacrolein, thioglycolic acid, thiomalic acid, 2-ethylhexylthioglycolate, α-methylstyrene dimer, terpinolene, etc. Water-soluble polymerization initiators such as potassium persulfate, sodium persulfate and ammonium persulfate, cumene hydroperoxide, benzoyl peroxide, t-butyl hydroperoxide, acetyl peroxide, diisopropylbenzene hydroperoxide, 1,1,3, An oil-soluble polymerization initiator such as 3-tetramethylbutyl hydroperoxide, a reducing agent ferrous sulfate, sulfite, hydrogen sulfite, pyrosulfite, nithionite, nitionate, thiosulfate, or , reducing sulfonates such as formaldehyde sulfonate and benzaldehyde sulfonate, L-ascorbic acid, tartaric acid, carboxylic acids such as citric acid, further reducing sugars such as dextrose and saccharose, further dimethylaniline, tri It is also possible to use one or more additives each of amines such as ethanolamine. There is no particular limit to the amount of these additives used, but considering the effect on the product cost and the appearance of the final product, each in the range of 0.01 to 5 parts by weight per 100 parts by weight of the total monomers. It is preferred to use

Surfactants used in emulsion polymerization of the thermoplastic emulsion contained in the fiber bundling composition of the present invention are not particularly limited. salts, aliphatic sulfonates, aliphatic carboxylates, nonionic surfactants such as acetylene glycol surfactants, acetylene alcohol surfactants, polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, Ethers such as polyoxyethylene dodecylphenyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene alkyl ether, polyoxyalkylene alkyl ether, polyoxyethylene oleic acid, polyoxy Esters such as ethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate, polyoxyethylene stearate, dimethylpolysiloxane and other fluorine-containing surfactants such as fluorine alkyl esters and perfluoroalkyl carboxylates.

One or more of these can be used, and it is preferable to use them in the range of 0.05 to 10 parts by weight per 100 parts by weight of all the monomers. If the amount is less than 0.05 parts, the stability of the polymerization liquid is poor, and if the amount exceeds 10 parts by weight, a large amount of gas is generated during molding of the final product, resulting in the problem of damaging the surface of the molded product. The range is preferably 0.1 to 8 parts by weight, more preferably 0.5 to 5 parts by weight.

Furthermore, known electrolytes, polymerization accelerators, chelating agents and the like can be used during polymerization.

The polymerization temperature during emulsion polymerization is preferably in the range of 40 to 80° C., and the polymerization time is preferably in the range of 3 to 15 hours.

The fiber bundling composition of the present invention contains at least one of acetylene glycol-based nonionic surfactants and dialkylsulfosuccinate-based anionic surfactants.

Acetylene glycol-based nonionic surfactants are compounds represented by the following general formula (1) or (2).

R1, R2, R3 and R4 in the general formula (1) each represent an alkyl group having 1 to 5 carbon atoms. R1, R2, R3 and R4 preferably have bilaterally symmetrical structures centering on the acetylene group.

R5, R6, R7 and R8 in the general formula (2) each represent an alkyl group having 1 to 5 carbon atoms. m and n are each an integer of 1 or more and 25 or less, and m+n is 2 or more and 40 or less. OE is an oxyethylene chain (--O-- _CH.sub.2 -- _CH.sub.2-- ) and OP is an oxypropylene chain (--O-- _CH.sub.2 --CH[ _CH.sub.3 ]--). OE and OP may each be single-stranded or mixed-stranded. R5, R6, R7 and R8 preferably have a bilaterally symmetrical structure centering on the acetylene group.

Acetylene glycol-based nonionic surfactants are manufactured by Nissin Chemical Industry Co., Ltd. under the name of "Surfynol (registered trademark)" or "Olfine (registered trademark)", and manufactured by Kawaken Fine Chemicals Co., Ltd. under the name of "Acetylenol (registered trademark)". Trademark)”.

Acetylene glycol-based nonionic surfactants include 2,4,7,9-tetramethyl-5-decyne-4,7-diol or 2,4,7,9-tetramethyl-5-decyne-4,7- Ethoxylates of diols are preferred.

The dialkylsulfosuccinate-based anionic surfactant is not particularly limited, but one having an alkyl group with 8 to 16 carbon atoms is preferable. Examples of salts include alkali metal salts such as sodium salts and potassium salts, alkaline earth metal salts, ammonium salts, and organic amine salts such as alkanolamines. Specific examples of the dialkylsulfosuccinate include sodium dioctylsulfosuccinate, magnesium dioctylsulfosuccinate, triethanolamine dioctylsulfosuccinate, sodium didecylsulfosuccinate, sodium didodecylsulfosuccinate (sodium dilaurylsulfosuccinate). salt), didodecylsulfosuccinate magnesium salt, ditetradecylsulfosuccinate lithium salt, dihexadecylsulfosuccinate potassium salt, and the like. As for these dialkylsulfosuccinates, one dialkylsulfosuccinate may be used alone, or two or more dialkylsulfosuccinates may be used in combination.

Among them, sodium dioctyl sulfosuccinate is preferable from the viewpoint of improving bending strength.

The content of at least one of the acetylene glycol nonionic surfactant and the dialkylsulfosuccinate anionic surfactant is preferably 0.5 to 10 parts by weight based on 100 parts by weight of the thermoplastic resin emulsion. , more preferably 0.7 to 3.2 parts by weight. By adjusting it within this range, the adhesion between the resin-impregnated fiber and the thermoplastic resin tends to be excellent.

At least one of the acetylene glycol-based nonionic surfactant and the dialkylsulfosuccinate-based anionic surfactant may be added during the production of the thermoplastic resin emulsion, or may be added after the completion of the production of the thermoplastic resin emulsion. good.

In addition, the composition for fiber bundling of the present invention contains a dispersant, a lubricant, an antifoaming agent, a preservative, an antioxidant, an ultraviolet absorber, a light stabilizer, a coloring agent, an antistatic agent, a plasticizer, and the like. It is possible to mix and use within a range that does not impair the effects of the invention.

The content of the thermoplastic resin emulsion (in terms of solid content) in the fiber bundling composition of the present invention is preferably 80% by weight or more, more preferably 90% by weight or more.

The weight-average molecular weight of the thermoplastic resin emulsion in the fiber bundling composition of the present invention is preferably in the range of 1.0×10 ⁴ to 8×10 ⁴ . If the weight-average molecular weight is lower than 1.0×10 ⁴ , the strength of the final product, which is the object of the present invention, will be inferior, and if it exceeds 8×10 4 , the impregnation between the carbon fibers, which is the feature of the present invention, will be reduced. . More preferably 2×10 ⁴ to 7.5×10 ⁴ , still more preferably 2.5×10 ⁴ to 7×10 ⁴ , particularly preferably 3.5×10 ⁴ to 6.8×10 ⁴ , most preferably It is in the range of 4×10 ⁴ to 6.5×10 ⁴ .

The weight-average molecular weight of the thermoplastic resin emulsion was measured using a commercially available gel permeation chromatogram (GPC) measuring device equipped with a UV detector and a column (MIXD-B manufactured by Agilent) at a column temperature of 50°C and a solvent It is a polystyrene-equivalent molecular weight measured under the conditions of tetrahydrofuran (THF), a flow rate of 1 ml/min, and a detection wavelength of 254 nm.

Although the glass transition temperature of the solid content of the thermoplastic resin emulsion in the fiber bundling composition of the present invention is not particularly limited, it is preferably in the range of 30 to 200° C. from the standpoint of the strength of the final product. The range is more preferably 35 to 190°C, still more preferably 60 to 140°C, and particularly preferably 80 to 120°C. This glass transition temperature can be measured according to JIS K7121-2012. The method for extracting the solid content in the thermoplastic resin emulsion is not particularly limited, but it can be obtained, for example, by drying the thermoplastic resin emulsion in a dryer adjusted to 90° C. for 10 hours.

The fiber bundling composition of the present invention should have a dynamic surface tension of 25 to 55 mN/m, preferably 29 to 40 mN/m. If the dynamic surface tension is more than 55 mN/m, the wettability of the fiber bundling composition to the fibers is lowered, and the adhesion between the thermoplastic resin and the fibers is deteriorated. On the other hand, if the dynamic surface tension is less than 25 mN/m, it may be difficult to control the amount of the fiber bundling composition attached to the fibers.

Dynamic surface tension can be measured, for example, by the method described in Examples.

The dynamic surface tension can be adjusted, for example, by the type and amount of surfactant added to the fiber bundling composition.

The method for bundling the fiber bundling composition of the present invention into fibers is not particularly limited, and it is possible to select one or a combination of two or more of the methods such as spray method, coating method and impregnation method.

Fibers to be bundled with the fiber bundling composition of the present invention include carbon fibers, glass fibers, boron fibers, silicon carbide fibers, metal fibers such as aluminum fibers, stainless steel fibers, copper fibers and nickel fibers, polyamide fibers and polyester fibers. , polyarylate fibers, polyimide fibers, and (nano)cellulose fibers. Furthermore, these fibers can be used singly or in combination of two or more. Among them, carbon fiber is most preferable. In addition to ordinary carbon fibers, carbon fibers include carbon fibers coated with metal such as nickel, and there are no particular restrictions on the form thereof, and may be continuous fibers, chopped fibers, milled shapes, non-woven fabrics, etc. Any form can be selected according to the requirements.

Although the content ratio of the fiber bundling composition and the fibers in the present invention is not particularly limited, the fiber bundling composition is 1 to 20 wt. parts, and 99 to 80 parts by weight of fibers.

In the resin-impregnated fiber of the present invention, the method for evaporating moisture after the fiber bundling composition is bundled onto the fiber is not particularly limited, and examples include a method using a dryer, a method of irradiating with infrared rays, and continuous drying. Depending on the purpose, it is possible to adopt a method of passing through a machine. Above all, in order not only to evaporate the moisture but also to melt the bundled fiber bundling composition and more uniformly coat the fiber surface, the glass transition temperature of the fiber bundling composition + 1 m or more adjusted to 60 ° C. or higher It is preferable to dry while continuously passing through a dryer having tracks at a speed of 0.5 m/min or more.

The resin-impregnated fiber of the present invention can be melt-kneaded with a thermoplastic resin and used as a fiber-reinforced thermoplastic resin composition. Furthermore, it can also be used as a laminate laminated with a thermoplastic resin sheet or film.

Examples of the thermoplastic resin to be combined with the resin-impregnated fiber of the present invention include polystyrene (PS), high-impact polystyrene (HIPS), acrylonitrile-butadiene rubber-styrene copolymer (ABS), acrylonitrile-ethylene propylene rubber-styrene copolymer. Polymer (AES), acrylonitrile-acrylic rubber-styrene copolymer (ASA), acrylonitrile-styrene copolymer (AS) and other styrene resins, polyethylene (PE), polypropylene (PP) and other polyolefin resins, polycarbonate ( PC), polyethylene terephthalate (PET), polyester resins such as polybutylene terephthalate (PBT), polymethyl methacrylate resin (PMMA), polyamide resin (PA), thermoplastic polyurethane resin (TPU), polylactic acid resin (PLA), poly Examples include alloys of ether sulfone (PES), polyphenylene sulfide (PPS) or styrenic resin and one or more resins selected from polycarbonate (PC), polyamide resin (PA) and polylactic acid resin (PLA). , it is possible to use one or a combination of two or more according to the required performance of the final product. Among them, styrene resins, polyester resins, polyamide resins, and alloys of styrene resins and polyester resins or polyamides are preferred from the viewpoint of the balance between moldability and strength of the final product.

The thermoplastic resin to be combined with the resin-impregnated fiber of the present invention includes, for example, light stabilizers, antioxidants, heat stabilizers, ultraviolet absorbers, lubricants, flame retardants, flame retardant aids, plasticizers, pigments, dyes, and the like. can also contain various additives.

The fiber-reinforced thermoplastic resin composition obtained by melt-kneading the resin-impregnated fiber and thermoplastic resin of the present invention can be, for example, injection molding, multilayer extrusion molding, film molding, sheet molding, inflation molding, press molding, SMC. A molded product can be obtained by adopting a processing method according to the purpose, such as a molding method or an LFT-D method. In some cases, it is also possible to interpose a step of pre-shaping.

A laminate obtained by laminating a layer comprising the resin-impregnated fiber of the present invention with a thermoplastic resin sheet or film can be molded by press molding or the like. In some cases, it is also possible to interpose a step of pre-shaping.

There is no particular limitation on the processing temperature of the molded product, and it is possible to select any temperature according to the properties of the thermoplastic resin used, but it is preferable to mold in the range of 180 to 270 ° C. , and more preferably in the range of 180 to 250°C.

EXAMPLES Hereinafter, the present embodiment will be described in more detail using Examples and Comparative Examples, but the present embodiment is not limited by the following Examples. Various physical properties in each example and comparative example are measured by the following methods.

The obtained thermoplastic resin emulsion was dried at room temperature for a whole day and night, and then dried in an oven at 70° C. for 1 hour to obtain a measurement sample. After that, a solution prepared by dissolving 0.02 g of the measurement sample in 10 ml of tetrahydrofuran (THF) was measured using a gel permeation chromatogram (GPC) measurement device under the following conditions.
Detector: UV
Column: MIXD-B manufactured by Agilent
Column temperature: 50°C
Solvent: Tetrahydrofuran (THF)
Flow rate: 1 ml/min,
Detection wavelength: 254 nm
Standard sample: Polystyrene
Glass-transition temperature
The resulting thermoplastic resin emulsion was dried in an oven at 90° C. for 10 hours to prepare a measurement sample. After that, it was measured according to JIS K7121-2012 using a differential scanning calorimeter.

Adjusting the dynamic surface tension sample concentration to 6%, using a bubble pressure dynamic surface tension meter (KRUSS BP100), the maximum bubble pressure method, temperature 30 ° C., capillary diameter 0.2 mm, surface life Measurement was performed under the condition of 100 ms. Unit: mN/m
bending strength
The bending strength was measured according to JIS K7074 using the test pieces obtained in each example and comparative example. Unit: MPa
<Method for producing thermoplastic resin emulsion>
After adding 45 parts of deionized water to a pressure-resistant polymerization reactor, the reactor was purged with nitrogen. 100 parts of a monomer mixture A consisting of 88 parts of styrene, 10 parts of acrylonitrile, and 0.8 parts of t-dodecylmercaptan was prepared, and this was mixed with 5% by weight of monomer mixture A-1 per 100% by weight of monomer mixture A. It was divided into 95% by weight monomer mixture A-2.

Then, the temperature of the reactor is raised to 75° C., 0.4 part of sodium dodecylbenzenesulfonate (in terms of solid content) and monomer mixture A-1 are added and sufficiently stirred, then 0.1 part of potassium persulfate is charged, Polymerization was initiated at 80°C.

After 1 hour from the start, the remaining monomer mixture A-2, a solution prepared by dissolving 2 parts of acrylic acid in 18 parts of deionized water, 1.7 parts of sodium dodecylbenzenesulfonate (solid content conversion) and 0 potassium persulfate A solution of .1 part in 30 parts deionized water was added continuously over a period of 7.5 hours. The polymerization temperature was maintained at 80° C. for 5 hours to complete the polymerization. Next, after adjusting the pH of the thermoplastic resin emulsion to about 7 with an aqueous solution of caustic soda, unreacted monomers and other low boiling point compounds are removed by steam distillation, the solid content is adjusted to 45%, and the thermoplastic resin emulsion is got

The solid content of the thermoplastic resin emulsion had a weight average molecular weight of 5.4×10 ⁴ and a glass transition temperature of 102°C.

<Method for producing fiber bundling composition-1>
1 part by weight (converted to solid content) of an acetylene glycol-based nonionic surfactant (product name “Surfinol (registered trademark) 104E”) is added to 100 parts by weight (converted to solid content) of a thermoplastic resin emulsion, and the mixture is sufficiently stirred. Then, a fiber bundling composition-1 was obtained. The dynamic surface tension measured by the method described above was 40 mN/m.

Surfynol (registered trademark) 104E: manufactured by Nissin Chemical Industry Co., Ltd. Substance name: 2,4,7,9-tetramethyl-5-decyne-4,7-diol <Production method of fiber bundling composition-2 ＞
Performed in the same manner as the fiber bundling composition-1 except that the amount of acetylene glycol-based nonionic surfactant (product name “Surfinol (registered trademark) 104E”) added was changed from 1 part by weight to 3 parts by weight. rice field. The dynamic surface tension measured by the method described above was 29 mN/m.

<Method for producing fiber bundling composition-3>
Except for changing the acetylene glycol-based nonionic surfactant (product name “Surfinol (registered trademark) 104E”) to a dialkyl sulfosuccinate-based anionic surfactant (product name “Sanmorin (registered trademark) OT-70”) was performed in the same manner as the fiber bundling composition-1.

The dynamic surface tension measured by the method described above was 44 mN/m.

Sanmorin (registered trademark) OT-70: manufactured by Sanyo Chemical Industries, Ltd. Substance name: sodium dioctyl sulfosuccinate <Method for producing fiber bundling composition-4>
Except for changing the acetylene glycol-based nonionic surfactant (product name “Surfinol (registered trademark) 104E”) to a dialkyl sulfosuccinate-based anionic surfactant (product name “Sanmorin (registered trademark) OT-70”) was performed in the same manner as the fiber bundling composition-2.

The dynamic surface tension measured by the method described above was 30 mN/m.

<Method for producing fiber bundling composition-5>
A thermoplastic resin emulsion was designated as fiber sizing agent composition-5. The dynamic surface tension measured by the method described above was 62 mN/m.

<Method for producing continuous resin-impregnated fiber-1>
Using a cloth binding device, fiber bundling composition-1 (in terms of solid content) is bundled so that the content is 15 parts by weight with respect to 100 parts by weight of carbon fiber, and then the obtained continuous resin-impregnated fiber is 180 parts by weight. C. for 3 minutes at a speed of 1 m/min to completely remove moisture, thereby obtaining a final continuous resin-impregnated fiber-1.

<Method for producing continuous resin-impregnated fibers-2 to 5>
Continuous resin-impregnated fibers-2 to 5 were obtained in the same manner as the continuous resin-impregnated fiber-1, except that the fiber bundling composition-1 was changed to fiber sizing agent compositions 2-5.

The carbon fiber used for the above-mentioned continuous resin-impregnated fiber is Tenax (registered trademark)-J STS40 F13 24K 1600tex manufactured by Teijin Limited.
<Method for producing a laminated product composed of continuous resin-impregnated fibers and thermoplastic resin>
After arranging a plurality of continuous resin-impregnated fibers in parallel to form a 20 cm square sheet, a polyamide resin film (Rayfan (registered trademark) N0 1401, thickness 40 μm, manufactured by Toray Advanced Film Co., Ltd.) and a carbon fiber content of 30% by weight. After preheating for 5 minutes with a pressure of 5 MPa using a compression molding machine NF37 with a set temperature of 250 ° C., hot press treatment is performed for 5 minutes with a pressure of 15 MPa. to produce a laminate having a thickness of 2 mm. A test piece having a width of 15 mm and a length of 150 mm was cut out from the obtained laminated product and used as a test piece for a bending test.

When the laminated product was produced, the direction of the carbon fibers was aligned in one direction, and the test piece for the bending test was cut out in the direction in which the direction of the carbon fiber and the direction of the long side of the test piece coincided. .

From Table 1, Examples 1 to 4 in which continuous resin-impregnated fibers produced using the fiber bundling composition of the present invention were laminated with a polyamide resin film were excellent in bending strength.

Comparative Example 1 was inferior in bending strength because the dynamic surface tension of the composition for fiber bundling of the present invention did not satisfy the specified range.

As described above, the product of the present invention is superior in product strength to conventional products, and is therefore suitable as a molded product for, for example, automobile parts and electrical appliances.

Claims (4)

A fiber bundling composition comprising a thermoplastic resin emulsion and at least one of an acetylene glycol-based nonionic surfactant and a dialkylsulfosuccinate-based anionic surfactant, and having a dynamic surface tension of 25 to 55 mN/m. A fiber bundling composition characterized by: The thermoplastic resin emulsion contains 40 to 98.5% by weight of an aromatic vinyl monomer and 1.5 to 60% by weight of another monomer copolymerizable with the aromatic vinyl monomer. 2. The fiber bundling composition according to claim 1, comprising a copolymer. A resin-impregnated fiber bundled with the fiber bundling composition according to claim 1 or 2. A molded product obtained by molding a laminate comprising a layer comprising the resin-impregnated fiber according to claim 3 and a thermoplastic resin layer.