JP2015165055A - Sizing agent for reinforcement fiber and use of the sizing agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sizing agent for reinforcement fiber, which is deposited on a reinforcement fiber strand to be used for reinforcing a matrix resin and thereby can easily widen the reinforcement fiber strand, and a reinforcement fiber strand and a fiber reinforced composite material using the sizing agent.SOLUTION: The sizing agent for reinforcement fiber comprises a water-soluble polymer (A) having a viscosity average molecular weight of 50000 to 10000000 and satisfying at least one of the conditions that the viscosity of a 5 wt.% aqueous solution of the sizing agent (at 25°C) is 50 to 10000 mPa s and that the viscosity of a 0.5 wt.% aqueous solution (at 25°C) is 10 to 2000 mPa s. The reinforcement fiber strand is obtained by depositing the sizing agent for reinforcement fiber on a raw reinforcement fiber strand. The fiber reinforced composite material comprises a matrix resin and the above reinforcement fiber strand.

Description

  The present invention relates to a sizing agent for reinforcing fibers and use thereof. Specifically, the present invention relates to a sizing agent for reinforcing fibers used to reinforce a matrix resin, a reinforcing fiber strand using the reinforcing fiber, and a fiber-reinforced composite material.

  Fiber reinforced composite materials in which plastic materials (referred to as matrix resins) are reinforced with various synthetic fibers are widely used for automobile applications, aerospace applications, sports / leisure applications, general industrial applications, and the like. Examples of fibers used in these composite materials include various inorganic fibers such as carbon fibers, glass fibers, and ceramic fibers, and various organic fibers such as aramid fibers, polyamide fibers, and polyethylene fibers. These various synthetic fibers are usually manufactured in a filament shape, and then processed into a sheet-like intermediate material called a unidirectional prepreg by a hot melt method or a drum winding method, processed by a filament winding method, or in some cases a textile Or it is used as a reinforced fiber through various high-order processing steps, such as being processed into a chopped fiber shape.

  On the other hand, in recent years, in order to obtain more effective properties such as tensile strength of fibers used as a reinforcing agent, the matrix resin is impregnated in a form called long fiber pellets, in the form of unidirectional sheets, tapes, and fabrics. Increasing cases of molding. In such a case, it is important in terms of shortening the molding process time and improving the physical properties of the obtained composite material that the matrix resin quickly impregnates inside the fiber strand, specifically between the fibers. .

However, it is extremely difficult to uniformly impregnate the matrix resin between the fibers. Therefore, the measure taken as a countermeasure for such a problem is to widen the reinforcing fiber strand into a thin sheet having a constant width so that the matrix resin can easily penetrate into the minute gaps between the fibers. It is.
The conventional widening of the reinforcing fiber strand is performed in a process in which the reinforcing fiber strand is unwound from the yarn supply body and is wound into a take-up tube. For example, Patent Document 1 discloses a method in which an air stream is passed in the crossing direction of reinforcing fiber strands to widen the strands constituting the reinforcing fiber strands in the width direction. However, this method requires a very expensive apparatus, and further increases the number of steps, leading to a problem that leads to an increase in cost, and a technique that can be more easily widened is desired.

  In addition, the conventional sizing agent is advantageous in that it has excellent converging properties and good workability, but the method of Patent Document 1 has a high film-forming property, so that it can be remarkably widened even when an air stream is passed through. Was inferior.

  Therefore, in the field of fiber reinforced composite materials, it is possible to uniformly and uniformly impregnate the matrix resin between the fibers and the fibers by expanding the reinforcing fiber strands more simply (hereinafter sometimes referred to as “expandability”). Development of a sizing agent is desired.

Republished patent WO97 / 41285

  In view of such a conventional technical background, an object of the present invention is to provide a reinforcing fiber sizing agent that can easily widen the reinforcing fiber strand by attaching it to the reinforcing fiber strand used to reinforce the matrix resin. It is to provide a reinforced fiber strand and a fiber reinforced composite material.

  As a result of intensive studies to solve the above problems, the present inventors have dramatically improved the widening property of the reinforcing fiber strand by using a sizing agent containing a specific water-soluble polymer (A). The present invention has been found.

  That is, the sizing agent for reinforcing fibers of the present invention contains a water-soluble polymer (A) having a viscosity average molecular weight of 50,000 to 10,000,000.

It is preferable that the water-soluble polymer (A) satisfies at least one of the following viscosity characteristics (1) and viscosity characteristics (2).
Viscosity characteristic (1): Viscosity (25 ° C.) of 5 wt% aqueous solution is 50 to 10,000 mPa · s
Viscosity characteristics (2): Viscosity (25 ° C.) of 0.5 wt% aqueous solution is 10 to 2000 mPa · s

The weight ratio of the water-soluble polymer (A) in the nonvolatile content of the sizing agent is preferably 0.01 to 20% by weight.
The water-soluble polymer (A) satisfies the viscosity characteristic (2), that is, the viscosity (25 ° C.) of a 0.5 wt% aqueous solution of the water-soluble polymer (A) is 10 to 2000 mPa. -It is preferable that it is s.

The sizing agent of the present invention is at least one selected from thermosetting resins and thermoplastic resins, and preferably further contains a resin component (B) excluding the water-soluble polymer (A).
The weight ratio of the resin component (B) in the nonvolatile content of the sizing agent is preferably 50 to 99.9% by weight.

The reinforcing fiber strand of the present invention is obtained by adhering the above-described reinforcing fiber sizing agent to a raw material reinforcing fiber strand.
The reinforcing fiber strand of the present invention is obtained by adhering a water-soluble polymer (A) having a viscosity average molecular weight of 50,000 to 10,000,000 to a raw material reinforcing fiber strand.

  The fiber-reinforced composite material of the present invention includes a matrix resin and the above-described reinforcing fiber strand.

By attaching the reinforcing fiber sizing agent of the present invention to the reinforcing fiber strand, the reinforcing fiber strand can be easily widened. The reinforcing fiber strand of the present invention can be easily widened.
By using the reinforcing fiber strand of the present invention, the matrix resin can be efficiently impregnated into the strand, and a fiber-reinforced composite material having excellent physical properties can be obtained.

A photograph that compares and explains the widening properties.

  The present invention is a reinforcing fiber sizing agent that can easily widen reinforcing fiber strands, and essentially contains a specific water-soluble polymer (A). Details will be described below.

[Water-soluble polymer (A)]
The water-soluble polymer (A), which is an essential component of the sizing agent of the present invention, has a viscosity average molecular weight of 50,000 to 10,000,000. By using such a specific water-soluble polymer (A), the expandability of the reinforcing fiber strand can be dramatically improved. Here, water-soluble means to dissolve 0.5% by mass or more in an aqueous medium.

  The viscosity average molecular weight of the water-soluble polymer (A) is more preferably from 500,000 to 8 million, further preferably from 1 million to 5 million, particularly preferably from 2 million to 4 million. When the viscosity average molecular weight is less than 50,000, the reinforcing fiber strand cannot be easily widened. If the viscosity average molecular weight exceeds 10 million, the reinforcing fiber strands can be easily widened, but the texture of the reinforcing fiber strands becomes too hard due to high film-forming properties, and they are wound tightly into a bobbin shape into a product package. It becomes difficult. As a result, problems such as breakage of the reinforcing fiber strands of the package during the transportation of the product package are likely to occur. Here, simply widening means that the reinforcing fiber strands are uniformly spread in the direction perpendicular to the fiber direction only by immersing and impregnating the sizing agent untreated reinforcing fiber strands by the Dip Nip method or the like. Say. In addition, the viscosity average molecular weight as used in the field of this invention says the value measured based on ASTMD2857 and D4020.

  Since the water-soluble polymer (A) can impart excellent widening properties to the reinforcing fiber strand, it is preferable that the water-soluble polymer (A) satisfies at least one of the above viscosity characteristics (1) and viscosity characteristics (2). The viscosity characteristic (1) refers to the viscosity at 25 ° C. when the water-soluble polymer (A) is dissolved in water to form a 5 wt% aqueous solution. The viscosity characteristic (2) refers to the viscosity at 25 ° C. when the water-soluble polymer (A) is dissolved in water to form a 0.5 wt% aqueous solution. In addition, the viscosity as used in the field of this invention means what was measured with the rotational viscometer (made by Brookfield) using the LV-1-4 spindle at 25 degreeC on rotation speed 12rpm, and measurement time 1 minute conditions. .

  The viscosity of the viscosity characteristic (1) is preferably 50 to 10000 mPa · s, more preferably 200 to 10000 mPa · s, and still more preferably 2000 to 10000 mPa · s. Furthermore, it is preferable that the water-soluble polymer (A) satisfies the viscosity characteristic (2) because excellent spreading property can be imparted to the reinforcing fiber strand. The viscosity of the viscosity characteristic (2) is preferably 10 to 2000 mPa · s, more preferably 100 to 1000 mPa · s, and still more preferably 100 to 800 mPa · s.

  Examples of the water-soluble polymer (A) include water-soluble synthetic polymers, semi-synthetic polymers, and natural polymers having a viscosity average molecular weight of 50,000 to 10,000,000. Examples of the water-soluble synthetic polymer include polyethylene oxide, carboxyvinyl polymer, sodium polyacrylate, polyvinyl methyl ether, polyvinyl pyrrolidone, polyacrylamide, ethylene oxide / propylene oxide block copolymer, and the like. Examples of the water-soluble semisynthetic polymer include methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, methyl hydroxypropyl cellulose, carboxymethyl starch, methyl starch, and propylene glycol alginate. Examples of the water-soluble natural polymer include gelatin, carrageenan, guar gum, quince seed, xanthan gum, pullulan, collagen, gum arabic, mannan, starch, dextran, casein, albumin, and hyaluronic acid.

  Among these, the water-soluble polymer (A) is preferably a water-soluble synthetic polymer having a viscosity average molecular weight of 50,000 to 10,000,000 because the excellent fiber spreading property can be imparted to the reinforcing fiber strand. The molecular weight is 50,000 to 10,000,000, and at least one selected from polyethylene oxide, carboxyvinyl polymer, sodium polyacrylate, polyvinyl methyl ether, polyvinyl pyrrolidone, polyacrylamide, and ethylene oxide / propylene oxide block copolymer. More preferably, the viscosity average molecular weight is 50,000 to 10,000,000, and selected from polyethylene oxide, sodium polyacrylate, polyvinyl methyl ether, polyacrylamide and ethylene oxide / propylene oxide block copolymer It is more preferable that the viscosity average molecular weight is 50,000 to 10,000,000, and polyethylene oxide, sodium polyacrylate, polyacrylamide and an ethylene oxide / propylene oxide block copolymer are particularly preferable. The viscosity average molecular weight is 50,000 to 10,000,000, and is most preferably at least one selected from polyethylene oxide and sodium polyacrylate.

[Resin component (B)]
The water-soluble polymer (A) described above is a component that mainly imparts widening properties to the reinforcing fiber strands. It is preferable that the sizing agent of the present invention further contains a resin component (B) that can impart sizing properties to the reinforcing fiber strands. The resin component (B) is not particularly limited as long as it is a component capable of imparting sizing properties, and any conventionally used resin component can be appropriately selected and used in the sizing agent for reinforcing fibers. Examples of the resin component (B) include at least one selected from thermosetting resins and thermoplastic resins, excluding the water-soluble polymer (A).

The weight average molecular weight of the resin component (B) is preferably 20000 or less, more preferably 100 to 15000, and still more preferably 200 to 10,000. When the weight average molecular weight is more than 20,000, even if the sizing property can be imparted to the reinforcing fiber strand, the texture of the reinforcing fiber strand becomes too hard due to the large weight average molecular weight, and it is difficult to make a product package by winding it tightly in a bobbin shape. Become. As a result, there is a possibility that problems such as breakage of the reinforcing fiber strands of the package may easily occur during transportation of the product package.
In addition, the weight average molecular weight as used in the field of this invention means the value converted into polystyrene by measuring with the gel permeation chromatograph (GPC) measuring method on the following measurement conditions.
(GPC measurement conditions)
Device: Device name “HPLC LC-6A SYSTEM” (manufactured by SHIMAZU)
Column: “KF-800P (10 mm × 4.6 mmφ)”, “KF-804 (300 mm × 8 mmφ)”, “KF-802.5 (300 mm × 8 mmφ)”, “KF-801 (300 mm × 8 mmφ)” ( (SHOEX manufactured by the above)
Mobile phase: Tetrahydrofuran (THF)
Flow rate: 1.0 ml / min
Sample volume: 100 μl (100-fold dilution)
Column temperature: 50 ° C
Calibration curve creation reference material: polystyrene (PSt)

  Examples of the thermosetting resin include an epoxy resin, an unsaturated polyester resin, a vinyl ester resin, a benzoxazine resin, a phenol resin, a urea resin, a melamine resin, and a thermosetting polyimide resin.

Examples of the epoxy resin include bisphenol type epoxy resin, amine type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, resorcinol type epoxy resin, phenol aralkyl type epoxy resin, naphthol aralkyl type epoxy resin, dicyclopentadiene type. Examples thereof include an epoxy resin, an epoxy resin having a biphenyl skeleton, an isocyanate-modified epoxy resin, a tetraphenylethane type epoxy resin, and a triphenylmethane type epoxy resin.
Here, the bisphenol type epoxy resin is obtained by glycidylation of two phenolic hydroxyl groups of a bisphenol compound. The bisphenol A type, bisphenol F type, bisphenol AD type, bisphenol S type, or halogens and alkyls of these bisphenols. Substituted products, hydrogenated products and the like can be mentioned. Moreover, not only a monomer but the high molecular weight body which has several repeating units can also be used conveniently.
Examples of the amine type epoxy resin include tetraglycidyldiaminodiphenylmethane, triglycidylaminophenol, triglycidylaminocresol, tetraglycidylxylylenediamine, halogens thereof, alkynol-substituted products, hydrogenated products, and the like.

Examples of the unsaturated polyester resin include unsaturated polyesters obtained by reacting an acid component containing an α, β-unsaturated dicarboxylic acid with an alcohol. Examples of the α, β-unsaturated dicarboxylic acid include maleic acid, fumaric acid, itaconic acid and the like, derivatives of these acid anhydrides, and the like, and these may be used in combination of two or more. In addition, as necessary, as acid components other than α, β-unsaturated dicarboxylic acids, saturated dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, adipic acid, sebacic acid, and acid anhydrides thereof, etc. The derivative may be used in combination with an α, β-unsaturated dicarboxylic acid. Examples of the alcohol include aliphatic glycols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, and 1,4-butanediol. , Cycloaliphatic diols such as cyclopentanediol and cyclohexanediol, hydrogenated bisphenol A, bisphenol A propylene oxide (1 to 100 mol) adducts, aromatic diols such as xylene glycol, trimethylolpropane and pentaerythritol Alcohol etc. can be mentioned and these 2 or more types may be used together.
Specific examples of the unsaturated polyester resin include, for example, a condensate of fumaric acid or maleic acid and bisphenol A ethylene oxide (hereinafter abbreviated as EO) adduct, fumaric acid or maleic acid and bisphenol A propylene oxide (hereinafter, And abbreviated as PO.) Condensates with adducts, condensates of fumaric acid or maleic acid with EO and PO adducts of bisphenol A (EO and PO addition may be random or block), and the like. it can.

  Examples of the vinyl ester resin include an epoxy (meth) acrylate obtained by esterifying the epoxy resin and an α, β-unsaturated monocarboxylic acid. Examples of the α, β-unsaturated monocarboxylic acid include acrylic acid, methacrylic acid, crotonic acid, tiglic acid and cinnamic acid, and two or more of these may be used in combination. Specific examples of the vinyl ester resin include, for example, a bisphenol type epoxy resin (meth) acrylate modified product (terminal (meth) obtained by reacting an epoxy group of a bisphenol A type epoxy resin and a carboxyl group of (meth) acrylic acid). Acrylate-modified resins and the like).

  Examples of the benzoxazine resin include o-cresol aniline type benzoxazine resin, m-cresol aniline type benzoxazine resin, p-cresol aniline type benzoxazine resin, phenol-aniline type benzoxazine resin, phenol-methylamine type benzoxazine. Resin, phenol-cyclohexylamine type benzoxazine resin, phenol-m-toluidine type benzoxazine resin, phenol-3,5-dimethylaniline type benzoxazine resin, bisphenol A-aniline type benzoxazine resin, bisphenol A-amine type benzoxazine Resin, bisphenol F-aniline type benzoxazine resin, bisphenol S-aniline type benzoxazine resin, dihydroxydiphenylsulfone-a Phosphorus benzoxazine resin, dihydroxydiphenyl ether-aniline benzoxazine resin, benzophenone benzoxazine resin, biphenyl benzoxazine resin, bisphenol AF-aniline benzoxazine resin, bisphenol A-methylaniline benzoxazine resin, phenol-diaminodiphenylmethane Type benzoxazine resin, triphenylmethane type benzoxazine resin, phenolphthalein type benzoxazine resin, and the like.

  Examples of the phenol resin include resins obtained by condensation of phenols such as phenol, cresol, xylenol, t-butylphenol, nonylphenol, cashew oil, lignin, resorcin, and catechol with aldehydes such as formaldehyde, acetaldehyde, and furfural. Examples thereof include novolak resins and resol resins. The novolak resin can be obtained by reacting phenol and formaldehyde in the same amount or in excess of phenol in the presence of an acid catalyst such as oxalic acid. The resole resin can be obtained by reacting phenol and formaldehyde in the same amount or in excess of formaldehyde in the presence of a base catalyst such as sodium hydroxide, ammonia or organic amine.

Examples of the urea resin include a resin obtained by condensation of urea and formaldehyde.
Examples of the melamine resin include a resin obtained by polycondensation of melamine and formaldehyde.

  Examples of the thermosetting polyimide resin include a resin containing at least one selected from a phenylethynyl group, a nadiimide group, a maleimide group, and an acetylene group at least in the main structure and containing an imide ring in the main structure or in the main chain. Can be mentioned.

  Examples of thermoplastic resins include polyurethane resins, polyolefin resins, polyamide resins, polyester resins, polyether resins, polyacetal resins, polyphenylene ether resins, polysulfide resins, polyether ketone resins, and polycarbonate resins. , Polyimide resins, polysulfone resins, halogen-containing resins, styrene resins, (meth) acrylic resins, thermoplastic elastomers, and the like.

The polyurethane-based resin can be obtained by a reaction of diisocyanates, polyols and, if necessary, a chain extender. Examples of the diisocyanates include aliphatic diisocyanates such as hexamethylene diisocyanate and 2,2,4-trimethylhexamethylene diisocyanate, alicyclic diisocyanates such as 1,4-cyclohexane diisocyanate and isophorone diisocyanate, phenylene diisocyanate, and tolylene diene. Examples thereof include aromatic diisocyanates such as isocyanate and diphenylmethane-4,4′-diisocyanate, and aromatic aliphatic diisocyanates such as xylylene diisocyanate. As diisocyanates, compounds in which an alkyl group (for example, a methyl group) is substituted on the main chain or ring may be used.
Examples of the diol include polyester diols (C4-12 aliphatic dicarboxylic acid components such as adipic acid, C2-12 aliphatic diol components such as ethylene glycol, propylene glycol, butanediol, and neopentyl glycol, and ε-caprolactone. Polyester diol obtained from C4-12 lactone component, etc.), polyether diol (polyethylene glycol, polypropylene glycol, polyoxyethylene-polyoxypropylene block copolymer, polyoxytetramethylene glycol, bisphenol A-alkylene oxide adduct, etc. ), Polyester ether diol (polyester diol using the above polyether diol as part of the diol component), and the like.
Furthermore, examples of the chain extender include diamines in addition to C2-10 alkylene diols such as ethylene glycol and propylene glycol. Examples of diamines include 2 to 10 carbon atoms such as ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, trimethylhexamethylenediamine, 1,7-diaminoheptane, and 1,8-diaminooctane. Linear or branched alkylene diamines, aliphatic diamines such as linear or branched polyalkylene polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dipropylenetriamine; isophorone diamine, bis (4- Alicyclic diamines such as amino-3-methylcyclohexyl) methane and bis (aminomethyl) cyclohexane; aromatic diamines such as phenylenediamine, xylylenediamine, and diaminodiphenylmethane; It can gel.

  Examples of the polyolefin-based resin include polyethylene, polypropylene, ethylene-propylene copolymer, homopolymers or copolymers of olefins such as poly (methylpentene-1), and copolymers of olefins and copolymerizable monomers ( Ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer, etc.). These polyolefin resins can be used alone or in combination of two or more. Polyolefin resins include polypropylene resins having a propylene content of 50% by weight or more (particularly 75 to 100% by weight) such as polypropylene, propylene-ethylene copolymer, propylene-butene copolymer, propylene-ethylene-butene copolymer. Polymers and the like are included.

Examples of the polyamide-based resin include aliphatic polyamide-based resins, alicyclic polyamide-based resins, and aromatic polyamide-based resins having an amide bond by polycondensation of a carboxyl group and an amino group. Usually, an aliphatic polyamide resin is used.
Examples of the aliphatic polyamide-based resin include an aliphatic diamine component (C4-10 alkylenediamine such as tetramethylenediamine and hexamethylenediamine) and an aliphatic dicarboxylic acid component (C4− such as adipic acid, sebacic acid, and dodecanedioic acid). A lactam (ε-caprolactam) using ring-opening polymerization of lactam (eg, polyamide 46, polyamide 66, polyamide 610, polyamide 612, polyamide 612, polyamide 1010, polyamide 1012, polyamide 1212, etc.) , C4-20 lactam such as ω-laurolactam) or aminocarboxylic acid (carbon number C4-20 aminocarboxylic acid such as ω-aminoundecanoic acid) homopolymer or copolymer (for example, polyamide 6, polyamide 11, Polyamide 1 Etc.), these polyamide component is copolymerized copolyamide (e.g., polyamide 6/11, polyamide 6/12, polyamide 66/11, and polyamide 66/12) and the like can be raised to.
Examples of the alicyclic polyamide-based resin include polyamides in which at least a part of the aliphatic diamine component and / or aliphatic dicarboxylic acid component is replaced with an alicyclic diamine and / or alicyclic dicarboxylic acid. be able to. Examples of the alicyclic polyamide include the aliphatic dicarboxylic acid component and the alicyclic diamine component (C5-8 cycloalkyldiamine such as cyclohexyldiamine; bis (aminocyclohexyl) methane, 2,2-bis ( And bis (aminocyclohexyl) alkanes such as aminocyclohexyl) propane) and the like.
Examples of the aromatic polyamide-based resin include polyamides in which at least one of the aliphatic diamine component and the aliphatic dicarboxylic acid component has an aromatic component. Examples of aromatic polyamides include polyamides whose diamine component has an aromatic component (condensates of aromatic diamines (such as metaxylylenediamine) and aliphatic dicarboxylic acids), and polyamides whose dicarboxylic acid component has an aromatic component. (Condensates of aliphatic diamines (trimethylhexamethylenediamine, etc.) and aromatic dicarboxylic acids (terephthalic acid, isophthalic acid, etc.), diamine components and dicarboxylic acid components are both polyamides having an aromatic component (poly (m- And wholly aromatic polyamides such as phenylene isophthalamide).
The polyamide-based resin further includes a polyamide having a dimer acid as a dicarboxylic acid component, a small amount of a polyfunctional polyamine and / or a polycarboxylic acid component, a polyamide having a branched chain structure, and a modified polyamide (N-alkoxymethyl polyamide). Etc.), high impact-resistant polyamides obtained by mixing or graft polymerization of modified polyolefins, polyamide elastomers having polyether as a soft segment, and the like.

Examples of the polyester resin include aliphatic polyester resins and aromatic polyester resins. Usually, an aromatic polyester resin, for example, a polyalkylene arylate resin or a saturated aromatic polyester resin is used.
Examples of aromatic polyester resins include poly C2-4 alkylene terephthalates such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT); poly C2-4 alkylene naphthalates (for example, polyethylene naphthalate) corresponding to the polyalkylene terephthalate. Phthalate, etc.); 1,4-cyclohexyldimethylene terephthalate (PCT)) and the like. The aromatic polyester resin may be a copolyester containing an alkylene arylate unit as a main component (for example, 50% by weight or more). Examples of the copolymer component include ethylene glycol, propylene glycol, butanediol, and hexanediol. Examples thereof include asymmetric aromatic dicarboxylic acids such as C2-6 alkylene glycol, polyoxy C2-4 alkylene glycol, phthalic acid and isophthalic acid, or acid anhydrides thereof, and aliphatic dicarboxylic acids such as adipic acid. Further, a branched chain structure may be introduced into the linear polyester using a small amount of polyol and / or polycarboxylic acid. Furthermore, a modified polyester resin modified with a modifying compound (for example, an aromatic polyester resin having at least one selected from an amino group and an oxyalkylene group) may be used. Modification compounds include polyamines (ethylenediamine, trimethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, trimethylhexamethylenediamine, 1,7-diaminoheptane, 1,8-diaminooctane, etc. Aliphatic diamines such as linear or branched alkylene diamines of about 2 to 10; alicyclic diamines such as isophorone diamine, bis (4-amino-3-methylcyclohexyl) methane, bis (aminomethyl) cyclohexane For example, aromatic diamines such as phenylenediamine, xylylenediamine, diaminodiphenylmethane, etc.), polyols (for example, (poly) oxyethylene glycol, (poly) oxytrimethylene glycol, (poly) oxy) Propylene glycol, and (poly) (poly) oxy-C2-4 alkylene glycols such as oxytetramethylene glycol) and the like. The modification can be performed, for example, by heating and mixing the polyester resin and the modifying compound and utilizing amidation, esterification or transesterification.

  Examples of the polyether resins include polyoxyalkylene resins, polyphenylene ether resins, polysulfide resins (polythioether resins), and the like. Examples of the polyoxyalkylene resin include polyoxymethylene glycol, polyoxyethylene glycol, polyoxypropylene glycol, polyoxyethylene-polyoxypropylene block copolymer, polyoxy C1-4 alkylene glycol such as polyoxytetramethylene glycol Etc.

  The polyacetal resin may be a homopolymer (formaldehyde homopolymer) constituted by regular repetition of acetal bonds, and a copolymer (trioxane, ethylene oxide and / or 1) obtained by ring-opening polymerization or the like. , A copolymer with 3-dioxolane, etc.). Moreover, the terminal of the polyacetal resin may be blocked and stabilized.

  Examples of polyphenylene ether resins include various resins mainly composed of 2,6-dimethylphenylene oxide, such as copolymers of 2,6-dimethylphenylene oxide and phenols, and modified or blended styrene resins. Examples include polyphenylene ether resins. Examples of other modified polyphenylene ether resins include polyphenylene ether / polyamide, polyphenylene ether / saturated polyester, polyphenylene ether / polyphenylene sulfide, and polyphenylene ether / polyolefin.

  The polysulfide resin is not particularly limited as long as it is a resin having a thio group (—S—) in the polymer chain. Examples of such resins include polyphenylene sulfide resins, polydisulfide resins, polybiphenylene sulfide resins, polyketone sulfide resins, and polythioether sulfone resins. Further, the polysulfide-based resin may have a substituent such as an amino group like poly (aminophenylene sulfide).

  Examples of polyether ketone resins include polyether ketone resins obtained by polycondensation of dihalogenobenzophenones (dichlorobenzophenone, etc.) and dihydrobenzophenone, polyether ketone resins obtained by polycondensation of dihalogenobenzophenones and hydroquinone, etc. Can be mentioned.

  The polycarbonate resin may be an aliphatic polycarbonate resin, but is usually an aromatic polycarbonate resin such as an aromatic dihydroxy compound (such as a bisphenol compound such as bisphenol A or bisphenol S) and phosgene or a carbonic acid diester ( And aromatic polycarbonates obtained by reaction with diaryl carbonates such as diphenyl carbonate and dialkyl carbonates such as dimethyl carbonate.

  Examples of the polyimide resin include a thermoplastic polyimide resin such as a polyimide resin obtained by a reaction between an aromatic tetracarboxylic acid or an anhydride thereof (such as benzophenone tetracarboxylic acid) and an aromatic diamine (such as diaminodiphenylmethane). , Polyamideimide resin, polyesterimide resin and the like.

  Examples of the polysulfone resin include polysulfone resins obtained by polycondensation of dihalogenodiphenyl sulfone (dichlorodiphenyl sulfone, etc.) and bisphenols (bisphenol A or a metal salt thereof, etc.), polyether sulfone resins, polyallyl sulfone resins, etc. Can be mentioned.

  Examples of halogen-containing resins include, for example, polyvinyl chloride, polyvinylidene chloride, vinyl chloride-vinyl acetate copolymers, chlorine-containing vinyl resins such as vinylidene chloride-vinyl acetate copolymers, polyvinyl fluoride, polyvinylidene fluoride, poly Fluorine-containing vinyl resins such as chlorotrifluoroethylene and a copolymer of tetrafluoroethylene and a copolymerizable monomer can be exemplified. A preferred halogen-containing resin is a fluorine-containing vinyl resin (eg, polyvinyl fluoride, polyvinylidene fluoride, etc.).

  Examples of the styrene resin include a styrene monomer alone or a copolymer (polystyrene, styrene-vinyltoluene copolymer, styrene-α-methylstyrene copolymer, etc.), and a copolymer with a styrene monomer. Copolymer with volatile monomers (styrene-acrylonitrile copolymer (AS resin), (meth) acrylic acid ester-styrene copolymer (MS resin, etc.), styrene-maleic anhydride copolymer, styrene-butadiene Styrene copolymers such as copolymers; acrylonitrile-butadiene-styrene copolymer (ABS resin), high impact polystyrene (HIPS), acrylonitrile-acrylic ester-styrene copolymer (AAS resin), acrylonitrile-chlorination Polyethylene-styrene copolymer (ACS resin), acrylonitrile-ethylene pro Rengomu - styrene copolymer (AES resin), acrylonitrile - vinyl acetate - styrene copolymer (AXS resin) styrene graft copolymers such like) and the like.

  Examples of (meth) acrylic resins include (meth) acrylic monomers alone or copolymers, and copolymers of (meth) acrylic monomers and copolymerizable monomers. Can do. As (meth) acrylic monomers, (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylic acid (Meth) acrylic acid C1-10 alkyl ester such as 2-ethylhexyl; methacrylic acid C5-10 cycloalkyl ester such as cyclohexyl methacrylate; (meth) acrylic acid C6-10 aryl ester such as phenyl (meth) acrylate; (Meth) acrylic acid hydroxy C2-10 alkyl ester such as hydroxyethyl acrylate; (meth) acrylamide; (meth) acrylonitrile; (meth) acrylic acid glycidyl; and the like. Examples of the copolymerizable monomer include vinyl monomers such as vinyl acetate and vinyl chloride, and styrene monomers such as styrene and α-methylstyrene.

  Examples of thermoplastic elastomers include polyamide-based elastomers (a copolymer having polyamide as a hard phase and aliphatic polyether as a soft phase), and polyester-based elastomers (polyalkylene arylate as a hard phase, aliphatic polyethers and fats). A copolymer having an aromatic polyester as a soft phase) and a polyurethane elastomer (a copolymer having a short-chain glycol polyurethane as a hard phase and an aliphatic polyether or aliphatic polyester as a soft phase, for example, a polyester urethane elastomer, Ether urethane elastomers), polystyrene elastomers (block copolymers with polystyrene blocks as the hard phase and diene polymer blocks or their hydrogenated blocks as the soft phase), polyolefin elastomers (polystyrene or polypropylene) Elastomers comprising pyrene as a hard phase and ethylene-propylene rubber or ethylene-propylene-diene rubber as a soft phase, olefin-based elastomers composed of a hard phase and a soft phase having different crystallinity), polyvinyl chloride elastomers, Fluorine-based thermoplastic elastomers can be mentioned. As the aliphatic polyether, (poly) oxy C2-4 alkylene glycols (particularly polyoxyethylene glycol) described in the section of the polyester resin and the polyurethane resin can be used, and as the aliphatic polyester, a polyurethane resin is used. The polyester diol described in the section can be used. These thermoplastic elastomers can be used alone or in combination of two or more.

  The resin component (B) may be used singly or in combination of two or more, and may be partially or wholly modified for the purpose of improving water dispersibility.

[Sizing agent for reinforcing fibers]
The sizing agent for reinforcing fibers of the present invention essentially contains the water-soluble polymer (A). The weight ratio of the water-soluble polymer (A) in the non-volatile content of the sizing agent is preferably 0.01 to 20% by weight, more preferably 0.02 to 15% by weight, and even more preferably 0.1 to 5% by weight. 0.2 to 2% by weight is particularly preferable. If the weight ratio is less than 0.01% by weight, it may not be possible to impart excellent widening properties. On the other hand, if it exceeds 20% by weight, the reinforcing fiber strands can be easily widened, but the texture of the reinforcing fiber strands becomes too hard due to the high film-forming property, and it becomes difficult to wind the bobbin tightly into a product package. As a result, problems such as breakage of the reinforcing fiber strands of the package may easily occur during transportation of the product package. The non-volatile content in the present invention refers to an absolutely dry component when the sizing agent is heat treated at 105 ° C. to remove the solvent and the like and reach a constant weight.

  The weight ratio of the resin component (B) in the nonvolatile content of the sizing agent is preferably 50 to 99.9% by weight, more preferably 60 to 99.9% by weight, and even more preferably 70 to 99.9% by weight. 75-99.9% by weight is particularly preferred. If the weight ratio is less than 50% by weight, there may be a case where sufficient binding property cannot be imparted to the reinforcing fiber strand.

  The ratio of the water-soluble polymer (A) to 100 parts by weight of the resin component (B) is preferably 0.01 to 16 parts by weight from the viewpoint of imparting excellent widening properties and converging properties to the reinforcing fiber strands. 0.01-13 weight part is more preferable, and 0.01-5 weight part is further more preferable. When this ratio is less than 0.01 part by weight, it may not be possible to impart excellent widening properties. On the other hand, if the ratio is more than 16 parts by weight, the reinforcing fiber strands can be easily widened, but the texture of the reinforcing fiber strands becomes too hard due to high film-forming properties, and the product package is wound tightly in a bobbin shape. It becomes difficult to do. As a result, problems such as breakage of the reinforcing fiber strands of the package may easily occur during transportation of the product package.

  The sizing agent of the present invention may contain components other than the water-soluble polymer (A) and the resin component (B) described above as long as the effects of the present invention are not impaired. Examples of the other components include various surfactants, various smoothing agents, antioxidants, flame retardants, antibacterial agents, crystal nucleating agents, antifoaming agents, and the like. It may be used.

When the surfactant contains a resin that is water-insoluble or hardly soluble in the resin component (B) or other sizing agent, the surfactant can be used as an emulsifier to efficiently carry out aqueous emulsification.
The surfactant is not particularly limited, and a known one can be appropriately selected from nonionic surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants. Surfactant may use together 1 type (s) or 2 or more types.

Nonionic surfactants include, for example, alkylene oxide-added nonionic surfactants (higher alcohols, higher fatty acids, alkylphenols, styrenated phenols, benzylphenols, sorbitans, sorbitan esters, castor oil, hydrogenated castor oil, etc. And alkylene oxides such as oxides and propylene oxides (two or more types can be used together), polyalkylene glycols added with higher fatty acids, and ethylene oxide / propylene oxide copolymers. .
Examples of the anionic surfactant include carboxylic acid (salt), sulfate ester salt of higher alcohol / higher alcohol ether, sulfonate salt, phosphate ester salt of higher alcohol / higher alcohol ether, and the like.

Examples of cationic surfactants include quaternary ammonium salt type cationic surfactants (such as lauryltrimethylammonium chloride and oleylmethylethylammonium etosulphate), amine salt type cationic surfactants (polyoxyethylene laurylamine), and the like. Lactate etc.).
Examples of amphoteric surfactants include amino acid type amphoteric surfactants (such as sodium laurylaminopropionate), betaine type amphoteric surfactants (such as stearyl dimethyl betaine, lauryl dihydroxyethyl betaine), and the like.

  The sizing agent of the present invention can exhibit excellent film flexibility and uniform adhesion after limiting the use of a surfactant. If the surfactant is contained in a large amount, the heat resistance of the sizing agent is lowered, which is not preferable. From such a viewpoint, the proportion of the surfactant in the nonvolatile content of the sizing agent is preferably 20% by weight or less, more preferably 10% by weight or less, further preferably 5% by weight or less, and particularly preferably 1% by weight or less.

  The sizing agent of the present invention may contain water from the viewpoints of safety to the human body during handling, disaster prevention such as fire, and prevention of pollution of the natural environment. An organic solvent such as methyl alcohol, ethyl alcohol, isopropyl alcohol, acetone, or methyl ethyl ketone may be used as long as the effects of the present invention are not impaired.

The sizing agent of the present invention includes those having a high non-volatile content to those having a low non-volatile concentration, such as a treatment liquid to be adhered to the reinforcing fiber strand. The concentration of the non-volatile content of the sizing agent of the present invention is not particularly limited, and is appropriately selected in consideration of the stability as an aqueous dispersion, the viscosity easy to handle as a product, and the like. The weight ratio of the non-volatile component in the entire sizing agent is preferably 1 to 100% by weight, more preferably 2 to 100% by weight, and particularly preferably 5 to 100% by weight.
The total weight ratio of water and non-volatile components in the entire sizing agent is preferably 90% by weight or more, more preferably 95% by weight or more, still more preferably 99% by weight or more, and particularly preferably 100% by weight. If it is less than 90% by weight, that is, if it contains 10% by weight or more of the above-mentioned organic solvent and other low boiling point compounds that do not remain as non-volatile components during heat treatment, it will be safe for the human body during handling and prevent pollution of the natural environment. It may not be preferable from the viewpoint.

  In addition to the above-mentioned viewpoints of human safety and prevention of environmental pollution, the above-mentioned aqueous dispersion and aqueous solution may contain a solvent other than water, such as an organic solvent, from the viewpoint of preventing thickening and solidification of the aqueous dispersion and aqueous solution over time. Even if it is not contained or contained, it is preferably 10% by weight or less, more preferably 5% by weight or less, and still more preferably 1% by weight or less based on the entire sizing agent.

  There is no limitation in particular about the method of manufacturing the sizing agent of this invention, A well-known method is employable. A method in which each component constituting the sizing agent is poured into water under stirring to form an aqueous solution, a method of preparing an aqueous dispersion when producing each component constituting the sizing agent, and each component constituting the sizing agent under stirring A method of mixing and emulsifying and dispersing each component constituting the sizing agent in advance, mixing each component constituting the sizing agent, and softening the resulting mixture After heating as described above, a water-soluble polymer (in a method of gradually injecting water and applying phase inversion emulsification while applying mechanical shearing force using a homogenizer, homomixer, ball mill, etc., or in an oil bath in which a sizing agent is applied) Examples thereof include a method of mixing an aqueous solution of A) and an emulsified dispersion obtained by previously emulsifying and dispersing the resin component (B).

[Reinforcing fiber strand and manufacturing method thereof]
The reinforcing fiber strand of the present invention is a reinforcing fiber for reinforcing the matrix resin, and the sizing agent for reinforcing fibers is attached to the raw material reinforcing fiber strand.
Further, the reinforcing fiber strand of the present invention can be expressed as having the above-mentioned water-soluble polymer (A) attached thereto. Furthermore, what attached the above-mentioned resin component (B) is suitable.
Since the reinforcing fiber strand of the present invention is excellent in widening property, the matrix resin can be uniformly and uniformly impregnated between the fibers.

The adhering amount of the non-volatile component of the sizing agent to the raw material reinforcing fiber strand can be appropriately selected and may be set to a necessary amount for the reinforcing fiber strand to have a desired function, but the adhering amount is 0 with respect to the raw material reinforcing fiber strand. It is preferably 1 to 20% by weight. In the reinforcing fiber strand in the form of long fibers, the adhesion amount is more preferably 0.1 to 10% by weight, and further preferably 0.3 to 5% by weight with respect to the raw synthetic fiber strand. Moreover, in the strand of the chopped fiber form (the state cut | disconnected by predetermined length), it is more preferable that it is 0.3-20 weight%, and 0.5-10 weight% is further more preferable.
When the adhesion amount of the sizing agent is small, it may be difficult to obtain the effects of the present invention relating to widening property and resin impregnation property. On the other hand, if the amount of the sizing agent attached is too large, the reinforcing fiber strands become too stiff and the handling property becomes worse, and the resin impregnation property becomes worse at the time of composite molding.

  The amount of the water-soluble polymer (A) attached is preferably 0.001 to 2% by weight, more preferably 0.003 to 1% by weight, and 0.03 to 0% with respect to the raw material reinforcing fiber strand. More preferred is .25% by weight. When the adhesion amount is less than 0.001% by weight, it may not be possible to impart excellent widening properties. On the other hand, when the adhesion amount exceeds 2% by weight, the reinforcing fiber strands can be easily widened, but the texture of the reinforcing fiber strands becomes too hard due to high film-forming properties, and the product package is wound tightly in a bobbin shape. It becomes difficult to do. As a result, problems such as breakage of the reinforcing fiber strands of the package may easily occur during transportation of the product package.

  The adhesion amount when the resin component (B) is adhered is preferably 0.05 to 9.99% by weight, more preferably 0.15 to 4.99% by weight, based on the raw material reinforcing fiber strand. 0.20 to 4.99% by weight is more preferable. When the adhesion amount is less than 0.05% by weight, it may not be possible to impart sufficient convergence to the reinforcing fiber strand. On the other hand, when the adhesion amount is more than 9.99% by weight, the texture of the reinforcing fiber strand becomes too hard due to the excessive adhesion amount, and it is difficult to make a product package by winding it tightly in a bobbin shape. As a result, problems such as breakage of the reinforcing fiber strands of the package may easily occur during transportation of the product package. Further, the adhesion ratio between the water-soluble polymer (A) and the resin component (B) in the reinforcing fiber strand is 0.01 to 0.1% when the water-soluble polymer (A) is 100% by weight. It is preferably 16% by weight, more preferably 0.01 to 13% by weight, and still more preferably 0.01 to 5% by weight. When the proportion is less than 0.01% by weight, it may not be possible to impart excellent widening properties. On the other hand, when the proportion is more than 16% by weight, the reinforcing fiber strands can be easily widened, but the texture of the reinforcing fiber strands becomes too hard due to high film-forming properties, and the product package is wound tightly in a bobbin shape. It becomes difficult to do. As a result, problems such as breakage of the reinforcing fiber strands of the package may easily occur during transportation of the product package.

The manufacturing method of the reinforcing fiber strand of the present invention includes the constituent components of the sizing agent such as the water-soluble polymer (A) and the resin component (B), and the weight ratio of the non-volatile component is 0.1 to 10% by weight. The preparation step of preparing a treatment liquid in which the total weight ratio of water and non-volatile content is 90% by weight or more, and the adhesion amount of non-volatile content to the raw material reinforcing fiber strand is 0.1 to 20% by weight, And an attaching step of attaching the treatment liquid to the reinforcing fiber strand.
In the preparation step, the weight ratio of the nonvolatile content in the treatment liquid is more preferably 0.1 to 10% by weight, and further preferably 0.3 to 5% by weight. The total weight ratio of water and nonvolatile components is more preferably 95% by weight or more, further preferably 99% by weight or more, and particularly preferably 100% by weight.
In the adhering step, a preferable amount of adhering nonvolatile components is as described above. The method for adhering the sizing agent to the raw material reinforcing fiber strand is not particularly limited as long as the sizing agent is attached to the raw material reinforcing fiber strand by a kiss roller method, roller dipping method, spray method or other known methods. Good. Among these methods, the roller dipping method is preferable because the sizing agent can be uniformly attached to the raw material reinforcing fiber strand.
There is no limitation in particular about the drying method of the obtained deposit, For example, it can heat-dry with a heating roller, a hot air, a hot plate, etc.

  In addition, in adhering the raw material reinforcing fiber strand of the sizing agent of the present invention, all the constituent components of the sizing agent may be attached after mixing, or constituent components such as the water-soluble polymer (A) and the resin component (B). Each of the above preparation steps and attachment steps may be provided and attached in two or more stages.

  The reinforcing fiber strand of the present invention is used as a reinforcing fiber of a composite material used as various matrix resins, and the form to be used may be a long fiber form or a chopped fiber form.

  As the (raw material) reinforcing fiber strand to which the sizing agent of the present invention can be applied, various inorganic fibers such as carbon fiber, glass fiber and ceramic fiber, aramid fiber, polyethylene fiber, polyethylene terephthalate fiber, polybutylene terephthalate fiber, polyethylene naphthalate Examples include strands such as various organic fibers such as fibers, polyarylate fibers, polyacetal fibers, PBO fibers, polyphenylene sulfide fibers, and polyketone fibers. From the viewpoint of the physical properties of the resulting fiber reinforced composite material, the (raw material) reinforced fiber strand includes carbon fiber, aramid fiber, polyethylene fiber, polyethylene terephthalate fiber, polybutylene terephthalate fiber, polyethylene naphthalate fiber, polyarylate fiber, polyacetal. At least one strand selected from fibers, PBO fibers, polyphenylene sulfide fibers and polyketone fibers is preferable, and carbon fiber strands are more preferable.

[Fiber-reinforced composite materials]
The fiber-reinforced composite material of the present invention includes a matrix resin and a reinforcing fiber strand as the above-mentioned reinforcing fiber. Since the reinforcing fiber strand is treated with the sizing agent of the present invention, it has excellent widening properties. As a result, the matrix resin can be uniformly and uniformly impregnated between the fibers and the fibers, and a fiber-reinforced composite material having excellent physical properties can be obtained.
The matrix resin is not particularly limited, and a known matrix resin can be appropriately selected and used. Examples of the matrix resin include a thermosetting matrix resin and a thermoplastic matrix resin.

Examples of the thermosetting matrix resin include an epoxy resin, an unsaturated polyester resin, a vinyl ester resin, a benzoxazine resin, a phenol resin, a urea resin, a melamine resin, and a thermosetting polyimide resin.
As thermoplastic matrix resins, polyurethane resins, polyolefin resins, polyamide resins, polyester resins, polyether resins, polyacetal resins, polyphenylene ether resins, polysulfide resins, polyether ketone resins, polycarbonate resins, Examples thereof include polyimide resins, polysulfone resins, halogen-containing resins, styrene resins, (meth) acrylic resins, and thermoplastic elastomers.
These matrix resins may be partially or wholly modified for the purpose of further improving the adhesiveness with the reinforcing fiber strands.

The method for producing the fiber reinforced composite material is not particularly limited, and known methods such as compound injection molding using chopped fibers and long fiber pellets, press molding using UD sheets and woven sheets, and other filament winding molding can be employed.
When the thermoplastic matrix resin and the reinforcing fiber are kneaded, if the thermoplastic matrix resin has a high melting point such as general-purpose engineer plastic or super engineer plastic, it is kneaded with the reinforcing fiber at a temperature of 200 ° C. to 400 ° C. above the melting point, Manufacture fiber reinforced composite materials.
The content of the reinforcing fiber strand in the fiber reinforced composite material is not particularly limited, and may be appropriately selected depending on the fiber type, form, matrix resin type, etc. 70 weight% is preferable and 20 to 60 weight% is more preferable.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, it is not limited to the Example described here. In addition, the percentage (%) and part shown in the following examples indicate “% by weight” and “part by weight” unless otherwise specified.

(Production Example A1)
Under stirring, 50 parts of polyethylene oxide (viscosity average molecular weight of 150,000 to 400,000) was gradually added to 950 parts of water to obtain an aqueous solution of polyethylene oxide A1 having a nonvolatile content of 5% by weight. When the obtained aqueous solution was measured with a rotary viscometer (manufactured by Brookfield) using an LV-1 spindle at 25 ° C. under a rotation speed of 12 rpm and a measurement time of 1 minute, it was 120 mPa · s.

(Production Example A2)
Under stirring, 50 parts of polyethylene oxide (viscosity average molecular weight 1100000 to 1500,000) was gradually added to 950 parts of water to obtain an aqueous solution of polyethylene oxide A2 having a nonvolatile content of 5% by weight. The obtained aqueous solution was measured with a rotary viscometer (manufactured by Brookfield) using an LV-3 spindle at 25 ° C. under the conditions of a rotation speed of 12 rpm and a measurement time of 1 minute, and was 5000 mPa · s.

(Production Example A3)
Under stirring, 5 parts of polyethylene oxide (viscosity average molecular weight 3300000 to 3800000) was gradually added to 995 parts of water to obtain an aqueous solution of polyethylene oxide A3 having a nonvolatile content of 0.5% by weight. The obtained aqueous solution was measured with a rotary viscometer (manufactured by Brookfield) using an LV-1 spindle at 25 ° C. under a rotation speed of 12 rpm and a measurement time of 1 minute, and was found to be 170 mPa · s.

(Production Example A4)
Under stirring, 5 parts of polyethylene oxide (viscosity average molecular weight 8000000 to 10000000) was gradually added to 995 parts of water to obtain an aqueous solution of polyethylene oxide A4 having a nonvolatile content of 0.5% by weight. The obtained aqueous solution was measured with a rotary viscometer (manufactured by Brookfield) using an LV-2 spindle at 25 ° C. under a rotation speed of 12 rpm and a measurement time of 1 minute, and was 850 mPa · s.

(Production Example A5)
Under stirring, 5 parts of UNIFLOKER UF-106 (manufactured by Unitika Co., Ltd., acrylamide / sodium acrylate copolymer) are gradually added to obtain an aqueous solution of polyethylene oxide A5 having a nonvolatile content of 0.5% by weight. It was. When the obtained aqueous solution was measured with a rotary viscometer (manufactured by Brookfield) using an LV-2 spindle at 25 ° C. under a rotation speed of 12 rpm and a measurement time of 1 minute, it was 1400 mPa · s.

(Production Example EP)
JER1001 (manufactured by Japan Epoxy Resin Co., Ltd., solid bisphenol A type epoxy resin, epoxy equivalent 450-500) / JER828 (manufactured by Japan Epoxy Resin Co., Ltd., liquid bisphenol A type epoxy resin, epoxy equivalent: 184-194) / POE ( 150) A composition comprising hardened castor oil ether = 40/40/20 (weight ratio) is charged into an emulsifying device, and water is gradually added under stirring to phase-invert and emulsify, and an epoxy resin EP aqueous dispersion having a nonvolatile content of 30% by weight Got.

(Production Example UPET)
An unsaturated polyester having an acid value of 2.5 was obtained by reacting 0.9 mol of maleic anhydride with 1.0 mol of an ethylene oxide 4 mol adduct of bisphenol A at 140 ° C. for 5 hours.
Next, an emulsifier was used to obtain a composition comprising the obtained unsaturated polyester / POE (150) hydrogenated castor oil ether / PO / EO (25/75) polyether (molecular weight 16000) = 80/10/10 (weight ratio). Then, water was gradually added under stirring to cause phase inversion emulsification to obtain an aqueous dispersion of unsaturated polyester UPET having a nonvolatile content of 30% by weight.

(Production example VE)
A composition consisting of bisphenol A diglycidyl ether acrylic acid adduct / ethylene oxide 150 mol addition-cured castor oil ether = 80/20 (weight ratio) was charged into an emulsifying device, and water was gradually added under stirring to phase-invert and emulsify. An aqueous dispersion of weight percent unsaturated polyester VE was obtained.

(Production example PU)
With nitrogen gas sealed in the reactor, 498 parts of terephthalic acid, 332 parts of isophthalic acid, 248 parts of ethylene glycol, 106 parts of diethylene glycol, 45 parts of tetramethylene glycol and 0.2 part of dibutyltin oxide were charged at 190 to 240 ° C. An esterification reaction was carried out for 10 hours to obtain an aromatic polyester polyol. Next, 1000 parts of the obtained aromatic polyester polyol was dehydrated at 120 ° C. under reduced pressure, and after cooling to 80 ° C., 680 parts of methyl ethyl ketone was charged and dissolved by stirring. Subsequently, 218 parts of isophorone diisocyanate and 67 parts of 2,2-dimethylolpropionic acid were added as a chain extender, and a urethanization reaction was carried out at 70 ° C. for 12 hours. After completion of the reaction, the reaction mixture was cooled to 40 ° C., 97 parts of 13.6% aqueous ammonia was added and neutralized, and then 2950 parts of water was added to form a water emulsion. The obtained water emulsion was treated under reduced pressure at 65 ° C. to distill off methyl ethyl ketone, and the water content was adjusted to obtain an aqueous dispersion of aromatic polyester urethane resin PU having a nonvolatile content of 30% by weight.

(Production Example PET)
950 parts of dimethyl isophthalate, 1000 parts of diethylene glycol, 0.5 part of zinc acetate and 0.5 part of antimony trioxide were charged in a reactor while nitrogen gas was sealed, and a transesterification reaction was carried out at 140 to 220 ° C. for 3 hours. . Next, 30 parts of 5-sodium sulfoisophthalic acid was added, esterification was performed at 220 to 260 ° C. for 1 hour, and then polycondensation reaction was performed at 240 to 270 ° C. under reduced pressure for 2 hours. The composition analysis result by NMR of the obtained aromatic polyester resin was as follows.
49% by mole of isophthalic acid
Diethylene glycol 50 mol%
5-sodium sulfoisophthalic acid 1 mol%
Subsequently, 200 parts of the obtained aromatic polyester resin and 100 parts of ethylene glycol monobutyl ether were charged into an emulsifier and stirred at 150 to 170 ° C. to make uniform. Subsequently, water 700 was gradually added with stirring to obtain an aqueous dispersion of an aromatic polyester resin PET having a nonvolatile content of 20% by weight.

(Production example PP)
In an autoclave equipped with a stirrer, maleic anhydride-modified polypropylene resin (propylene / maleic anhydride graft copolymerization ratio (% by weight): 95/5, weight average molecular weight: 30000), 228 parts, polyoxyethylene 8 mol addition oleyl 57 parts of ether and 15 parts of sodium hydroxide were charged, and the temperature was raised to 170 to 180 ° C. under nitrogen gas reflux and stirring. Next, 700 parts of stirring sewage was gradually added and stirred at 170 to 180 ° C. for 2 hours to uniformly dissolve the contents. Thereafter, the mixture was cooled to room temperature, moisture was adjusted, and an aqueous dispersion of polypropylene resin PP having a nonvolatile content of 30% by weight was obtained.

(Production example PAA)
A reaction vessel equipped with a cooling reflux apparatus was charged with 200 parts of N-methoxymethylated polyamide (“Rakkamide (registered trademark) 5003” manufactured by DIC, N-methoxymethylation rate: 30%), and 800 parts of methanol, It melt | dissolved with stirring at 60 degreeC. Next, 100 parts of acrylic acid and 2.4 parts of azobisisobutyronitrile were added, and graft polymerization was performed at 50 to 60 ° C. for 4 hours in a nitrogen atmosphere. 860 parts of water and 175 parts of 13.6% aqueous ammonia were added, and methanol was distilled off (the residual amount of methanol was 0.63%) to obtain an aqueous dispersion of hydrophilic polyamide resin PAA having a nonvolatile content of 20% by weight.

(Production Example PVA)
Under stirring, 50 parts of polyvinyl alcohol (polymerization degree 500, saponification degree 88) was gradually added to 950 parts of water to obtain an aqueous solution of polyvinyl alcohol PVA having a nonvolatile content of 5% by weight. The obtained aqueous solution was 9 mPa · s measured with a rotary viscometer (manufactured by Brookfield) using an LV-1 spindle at 25 ° C. under a rotation speed of 12 rpm and a measurement time of 1 minute.

(Other ingredients)
PEG: Polyethylene glycol having a weight average molecular weight of 400

[Examples 1 to 22, Comparative Examples 1 to 11]
Using the aqueous solution and the aqueous dispersion produced above, the mixture was stirred so as to have a nonvolatile composition shown in Tables 1 to 3, and diluted with water to prepare a sizing agent having a nonvolatile content concentration of 5% by weight. In addition, the numerical value of Tables 1-2 shows the weight ratio of each component (in the case of an aqueous dispersion, the non volatile matter) to the non volatile matter of a sizing agent. For example, the values of A1 to A5, EP, UPET, VE, PU, PET, PP, PAA, PVA, and PEG in Tables 1 to 3 are A1 to A5, EP, UPET, VE, and PU in the nonvolatile content of the sizing agent. , PET, PP, PAA, PVA, PEG non-volatile content weight ratio is shown.
Next, the sizing agent-treated carbon fiber strands (fineness: 800 tex, filament number: 12,000) were dipped and impregnated by the Dip Nip method, and then dried with hot air at 105 ° C. for 15 minutes to obtain sizing agent-treated carbon fibers. A strand was obtained. Using the obtained sizing agent-treated carbon fiber strand, the adhesion amount, the widening property, and the convergence property were evaluated by the following methods.

<Adhesion amount>
Sizing agent-treated carbon fiber strand W ₁ g (about 3 g) was treated in an electric furnace at 450 ° C. for 20 minutes to completely pyrolyze and volatilize the attached sizing agent. After cooling, the weight (W ₂ g) of the carbon fiber strand was measured, and the adhesion amount was calculated from the following formula.
Adhering amount (wt%) = ((W ₁ −W ₂ ) / W ₁ ) × 100

<Wideness>
About the sizing agent process carbon fiber strand, as shown in FIG. 1, the breadth width D (mm) was measured.

<Focusing property>
The focused state (degree of dispersion) when the carbon fiber strand was cut into short fibers of about 5 mm using stainless steel scissors was visually determined according to the following criteria.
○: Short fibers are almost the same as before cutting.
X: The short fibers are largely dispersed or cracked.

  As shown in Tables 1 to 3, the strands treated with the sizing agent of the examples are excellent in the widening property. On the other hand, it turns out that the strand which processed the sizing agent of the comparative example is only inferior to the breadth property.

  D Spread width (mm)

Claims (9)

  A sizing agent for reinforcing fibers comprising a water-soluble polymer (A) having a viscosity average molecular weight of 50,000 to 10,000,000. The sizing agent for reinforcing fibers according to claim 1, wherein the water-soluble polymer (A) satisfies at least one of the following viscosity characteristics (1) and viscosity characteristics (2).
Viscosity characteristic (1): Viscosity (25 ° C.) of 5 wt% aqueous solution is 50 to 10,000 mPa · s
Viscosity characteristics (2): Viscosity (25 ° C.) of 0.5 wt% aqueous solution is 10 to 2000 mPa · s   The sizing agent for reinforcing fibers according to claim 1 or 2, wherein the weight ratio of the water-soluble polymer (A) in the nonvolatile content of the sizing agent is 0.01 to 20% by weight.   The sizing agent for reinforcing fibers according to any one of claims 1 to 3, wherein the water-soluble polymer (A) satisfies the viscosity characteristic (2).   The reinforcement | strengthening in any one of Claims 1-4 which is at least 1 sort (s) chosen from a thermosetting resin and a thermoplastic resin, Comprising: The resin component (B) except the said water-soluble polymer (A) is further contained. Sizing agent for textiles.   The sizing agent for reinforcing fibers according to claim 5, wherein a weight ratio of the resin component (B) to a non-volatile content of the sizing agent is 50 to 99.9% by weight.   A reinforcing fiber strand in which the reinforcing fiber sizing agent according to any one of claims 1 to 6 is attached to a raw material reinforcing fiber strand.   A reinforcing fiber strand in which a water-soluble polymer (A) having a viscosity average molecular weight of 50,000 to 10,000,000 is adhered to a raw material reinforcing fiber strand.   A fiber-reinforced composite material comprising a matrix resin and the reinforcing fiber strand according to claim 7 or 8.