JP2020084376A - Fiber sizing agent, fiber bundle, and fiber product - Google Patents

Abstract

To provide a fiber sizing agent that can impart excellent adhesiveness between fiber and matrix resin and can realize both an excellent fiber sizing property and an excellent fiber opening property.SOLUTION: A fiber sizing agent contains a polyester (A), which has an aromatic ring and a functional group (a) represented by general formula (1). The number (m) of the functional groups (a) in each molecule of the polyester (A) is from 1 to 6, and the number of ester groups in each molecule of the polyester (A) is at least m+1.SELECTED DRAWING: None

Description

The present invention relates to a fiber sizing agent, a fiber bundle, and a fiber product.

BACKGROUND ART Composite materials of various resins and matrix resins such as unsaturated polyester resins, phenol resins, epoxy resins and polypropylene resins are widely used in fields such as sports equipment, leisure goods and aircraft.
Fibers such as glass fiber, carbon fiber, ceramic fiber, metal fiber, mineral fiber and slug fiber are used as fibers used in these composite materials. A sizing agent is usually added to these fibers in order to prevent fuzzing and yarn breakage in the processing step of forming the composite material.
However, the conventional sizing agent has a problem that the adhesion between the fiber and the matrix resin is insufficient in the matrix resin such as the vinyl ester resin and the unsaturated polyester resin.
In order to solve this problem, a fiber sizing agent (for example, Patent Document 1) in which an epoxy resin is dispersed in an aqueous medium by a urethane resin having an alkoxypolyoxyethylene structure and an epoxy group, or an epoxy group and an unsaturated group are contained in a molecule. A fiber sizing agent containing a compound having the same, a urethane acrylate and a polyurethane resin (for example, Patent Document 2) is known.

In order to improve the physical properties of the composite material, the adhesiveness between the fiber and the matrix resin is high from the viewpoint of effectively utilizing the characteristics of the fiber, and the openability of the fiber bundle is high in order to improve the impregnating property of the matrix resin, Also, from the viewpoint of handleability of the fiber bundle, it is important that the bundle property is good. Therefore, there is a demand for a sizing agent capable of forming a fiber bundle having excellent adhesiveness between the fiber and the matrix resin, high openability of the fiber bundle, and good handleability of the fiber.
However, the sizing agent proposed in Patent Document 1 does not sufficiently satisfy the adhesiveness between the fiber and the matrix resin, and as a result, there is a problem that the strength of the composite material is not sufficient. Although the adhesiveness with the matrix resin is good, there is a problem that the openability is insufficient.

JP, 2013-249562, A Patent No. 5497908

An object of the present invention is to provide a sizing agent for fibers, which can impart excellent adhesiveness between the fiber and the matrix resin and can have both excellent sizing property and openability.

［一般式（１）中、Ｒは、水素原子又は炭素数１〜３のアルキル基を表し、ポリエステル（Ａ）が複数のＲを有する場合は、同一でも異なっていても良い。］ The present inventors have arrived at the present invention as a result of studies to achieve the above object.
That is, the present invention provides a fiber sizing agent containing an aromatic ring and a polyester (A) having a functional group (a) represented by the general formula (1),
The number (m) of the functional groups (a) contained in one molecule of the polyester (A) is 1 to 6,
The number of ester groups contained in one molecule of the polyester (A) is m+1 or more; selected from the group consisting of carbon fibers, glass fibers, aramid fibers, ceramic fibers, metal fibers, mineral fibers and slug fibers. A fiber bundle obtained by treating at least one kind of fiber with the fiber sizing agent; a fiber product containing the fiber bundle.

[In the general formula (1), R represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and when the polyester (A) has a plurality of Rs, they may be the same or different. ]

INDUSTRIAL APPLICABILITY The fiber sizing agent of the present invention has the effects of being able to impart excellent adhesiveness between the fiber and the matrix resin, and being able to achieve both excellent sizing property and fiber-spreading property.

It is a figure showing arrangement of a carbon fiber bundle in evaluation of openability.

The fiber sizing agent of the present invention is a fiber sizing agent containing an aromatic ring and a polyester (A) having a functional group (a) represented by the general formula (1).

Examples of the polyester (A) include a polyester (A1) obtained by subjecting an ester having a hydroxy group and a carboxylic acid having a functional group (a) to an esterification reaction, an ester having a hydroxy group, and a polyisocyanate ( Examples include polyester (A2) obtained by subjecting an isocyanate obtained by subjecting γ) to a urethane reaction with a compound having a functional group (a) and a hydroxyl group.
The ester having a hydroxy group is an esterified product of carboxylic acid (α) and polyol (β), and may be polyester having carboxylic acid (α) and polyol (β) as essential constituent monomers [polyester In the case of, a polycarboxylic acid is used as the carboxylic acid (α)].
The hydroxy group contained in the “ester having a hydroxy group” may be a hydroxyl group derived from a polyol (β) located at the terminal of the ester, and in the case of polyester, a side chain of a constituent unit derived from each constituent monomer. Although it may be a hydroxy group derived from a hydroxyl group, it is preferably a hydroxy group derived from a polyol (β) located at the terminal of the polyester from the viewpoint of adhesiveness to the matrix resin.
The aromatic ring of the polyester (A) may be derived from a carboxylic acid (α) or a polyol (β), or may be derived from a carboxylic acid having a functional group (a). Alternatively, it may be derived from polyisocyanate (γ) or a compound having a functional group (a) and a hydroxyl group.
The polyester (A) may be used alone or in combination of two or more.

Examples of the carboxylic acid (α) include aliphatic carboxylic acid (α1) and aromatic carboxylic acid (α2).

Examples of the aliphatic carboxylic acid (α1) include chain saturated aliphatic carboxylic acid (α11), chain unsaturated aliphatic carboxylic acid (α12), alicyclic carboxylic acid (α13) and dimer acid (α14). Be done.

As the chain saturated aliphatic carboxylic acid (α11), a straight chain or branched chain saturated aliphatic carboxylic acid having 2 to 22 carbon atoms [straight chain or branched chain saturated aliphatic monocarboxylic group having 2 to 22 carbon atoms] Acids (acetic acid, 1-propionic acid, 1-butanoic acid, 1-pentanoic acid, 1-hexanoic acid, 1-heptanoic acid and 1-octanoic acid) and straight or branched chain saturated fats having 2 to 22 carbon atoms Group polycarboxylic acids (oxalic acid, malonic acid, succinic acid, glutaric acid, methylsuccinic acid, ethylsuccinic acid, dimethylmalonic acid, α-methylglutaric acid, β-methylglutaric acid, 2,4-diethylglutaric acid, isopropylmalonic acid , Adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, tridecanedicarboxylic acid, tetradecanedicarboxylic acid, hexadecanedicarboxylic acid, octadecanedicarboxylic acid, icosanedicarboxylic acid, Decyl succinic acid, dodecyl succinic acid, octadecyl succinic acid, etc.)] and the like.

The chain unsaturated aliphatic carboxylic acid (α12) is a straight chain or branched chain unsaturated aliphatic carboxylic acid having 4 to 22 carbon atoms [straight chain or branched chain unsaturated fatty acid having 4 to 22 carbon atoms]. Group monocarboxylic acids (linoleic acid, oleic acid, erucic acid, etc.) and linear or branched chain unsaturated aliphatic polycarboxylic acids having 4 to 22 carbon atoms (maleic acid, fumaric acid, citraconic acid, mesaconic acid, dodecenylsuccinic acid) Acid, pentadecenyl succinic acid, octadecenyl succinic acid, etc.)] and the like.

Examples of the alicyclic carboxylic acid (α13) include alicyclic carboxylic acid having 4 to 14 carbon atoms [alicyclic monocarboxylic acid having 4 to 14 carbon atoms (cyclopropanecarboxylic acid and cyclohexanecarboxylic acid) and 7 to 7 carbon atoms]. 14 alicyclic polycarboxylic acids (1,3- or 1,2-cyclopentanedicarboxylic acid, 1,2-, 1,3- or 1,4-cyclohexanedicarboxylic acid, 1,2-, 1,3- Or 1,4-cyclohexanediacetic acid, dicyclohexyl-4,4′-dicarboxylic acid, etc.) and the like.

Examples of the dimer acid (α14) include polycarboxylic acids which are dimers of chain unsaturated aliphatic carboxylic acids having 8 to 24 carbon atoms (oleic acid, linoleic acid, linolenic acid, etc.).

Examples of the aromatic carboxylic acid (α2) include an aromatic carboxylic acid having 7 to 14 carbon atoms [an aromatic monocarboxylic acid having 7 to 14 carbon atoms (benzoic acid, etc.) and an aromatic polycarboxylic acid having 8 to 14 carbon atoms ( Terephthalic acid, isophthalic acid, phthalic acid, phenylmalonic acid, phenylsuccinic acid, β-phenylglutaric acid, α-phenyladipic acid, β-phenyladipic acid, biphenyl-2,2′- or 4,4′-dicarboxylic acid , Naphthalenedicarboxylic acid, sodium 5-sulfoisophthalate, potassium 5-sulfoisophthalate, etc.]] and the like.

The carboxylic acids (α) may be used alone or in combination of two or more.
Of these, a chain saturated aliphatic carboxylic acid (α11), a chain unsaturated aliphatic carboxylic acid (α12) and an aromatic carboxylic acid (α2) are preferable from the viewpoint of focusing property, and more preferable are aromatic carboxylic acids. Acids (α2), particularly preferred are terephthalic acid, isophthalic acid and phthalic acid, most preferred are terephthalic acid and isophthalic acid.

Examples of the polyol (β) include aliphatic polyol (β1) and aromatic polyol (β2).
Examples of the aliphatic polyol (β1) include chain aliphatic polyol (β11), alicyclic polyol (β12), and alkylene oxide adducts of these polyols.
As the chain aliphatic polyol (β11), a chain aliphatic polyol having 2 to 10 carbon atoms (ethylene glycol, 1,2- or 1,3-propylene glycol, 1,4-butanediol, 1,6-hexane). And diol, 1,8-octanediol, 1,10-decanediol, neopentyl glycol and 2,2-diethyl-1,3-propanediol, glycerin and trimethylolpropane, pentaerythritol).
Examples of the alicyclic polyol (β12) include alicyclic polyols having 5 to 12 carbon atoms [1,3-cyclopentanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,4-cycloheptane. Diol, 2,2-bis(4-hydroxycyclohexyl)propane, 1,3,5-cyclohexanetriol and the like] and the like.

Examples of the aromatic polyol (β2) include aromatic polyols having 6 to 15 carbon atoms [polyols having a bisphenol skeleton (bisphenol A, bisphenol F, bisphenol S, etc. and hydroquinone, etc.], and alkylene oxide adducts of these polyols. Can be mentioned.

As the alkylene oxide added to the polyol, the above-mentioned alkylene oxide having 2 to 4 carbon atoms (ethylene oxide, 1,2- or 1,3-propylene oxide and 1,2-, 1,3-, 1,4- or 2,3-butylene oxide) and the like.
The number of moles of the alkylene oxide added to 1 mole of the polyol is 2 to 50 moles from the viewpoint of water solubility in the case of the aqueous solution described below, emulsification in the case of the aqueous emulsion described below, and adhesion with the matrix resin. It is preferable that [that is, the polyol (β) has a polyoxyalkylene chain].

As the polyol (β), one type may be used alone, or two or more types may be used in combination.
Among the polyols (β), the aromatic polyol (β2) is preferable from the viewpoint of focusing property, and it is more preferable that the aromatic polyol (β2) has a bisphenol skeleton. Further, the aromatic polyol (β2) is an alkylene oxide adduct (preferably 2 to 50 mol adduct) of an aromatic polyol having a bisphenol skeleton from the viewpoint of further improving the focusing property, and bisphenol A is particularly preferable. And the alkylene oxide adduct of bisphenol F.

The viscosity of the polyester having a hydroxy group at 100° C. is preferably 0.1 to 50 Pa·s, more preferably 0.2 to 30 Pa·s, and particularly preferably 0.3 to 20 Pa·s. is there.
If the viscosity is in the range of 0.1 to 50 Pa·s, better focusing properties can be obtained. The viscosity of the polyester at 100° C. is measured by a Brookfield type viscometer (BL type) in accordance with JIS K7117-1:1999 (corresponding to ISO2555:1990).

When the ester having a hydroxy group is a polyester, the equivalent ratio [(α) of the carboxy group of the carboxylic acid (α) constituting the polyester and the hydroxy group of the diol (β) constituting the polyester has The carboxyl group/(hydroxy group contained in (β)] is preferably 0.50 to 0.95, more preferably 0.50 to 0.85, from the viewpoint of improving the focusing property.

When the ester having a hydroxy group is a polyester, the polyester preferably has a number average molecular weight of 500 to 30,000 (hereinafter, abbreviated as Mn). When Mn is 500 or more, sufficient sizing properties are obtained, and when Mn is 50,000 or less, adhesiveness with the matrix resin is excellent.
The Mn is measured by gel permeation chromatography (hereinafter abbreviated as GPC). The Mn is more preferably 600 to 20,000, particularly preferably 700 to 10,000. Within this range, the bundling property and the adhesiveness with the matrix resin are further excellent.

In addition, the conditions of GPC used for the measurement of Mn of polyester are the following conditions, for example.
Model: Alliance (Nippon Waters Co., Ltd. liquid chromatograph)
Column: Guardcolumn Super HL
+TSK gel Super H4000
+TSK gel Super H3000
+TSK gel Super H2000
(All manufactured by Tosoh Corporation)
Column temperature: 40°C
Detector: RI (Refractive Index)
Eluent: Tetrahydrofuran Eluent flow rate: 0.6 ml/min Sample concentration: 0.25% by weight
Injection volume: 10 μl
Standard substance: Polystyrene (manufactured by Tosoh Corporation; TSK STANDARD POLYSTYRENE)

As a method for producing an ester having a hydroxy group, for example, a carboxylic acid (α) and/or an anhydride (α′) of the carboxylic acid (α) and a polyol (β) are charged at a predetermined molar ratio, and the reaction temperature is 100. A method may be mentioned in which water is distilled off under stirring at ˜250° C. and a pressure of −0.1 to 1.2 MPa.
Examples of the above-mentioned anhydride (α′) include the above-mentioned (α1) or (α2) anhydrides, specifically, succinic anhydride, maleic anhydride, phthalic anhydride and the like.

When producing an ester having a hydroxy group, it is preferable to add the catalyst in an amount of 0.05 to 0.5% by weight based on the weight of the ester. Examples of the catalyst include paratoluenesulfonic acid, dibutyltin oxide, tetraisopropoxy titanate and potassium oxalate titanate, and tetraisopropoxy titanate and potassium oxalate titanate are preferable from the viewpoint of reactivity and environmental influence. More preferred is potassium oxalate titanate.

As described above, the polyester (A) is a polyester (A1) obtained by esterifying an ester having a hydroxy group and a carboxylic acid having a functional group (a) represented by the general formula (1), and , An isocyanate having a hydroxy group ester and a polyisocyanate (γ) are subjected to a urethane reaction, and a compound having a functional group (a) and a hydroxyl group represented by the general formula (1) are subjected to a urethane reaction. Polyester (A2) and the like are included.

In the general formula (1), R represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and when the polyester (A) has a plurality of Rs, they may be the same or different.
Further, R is preferably a hydrogen atom or a methyl group from the viewpoint of adhesiveness with the matrix resin.

Examples of the carboxylic acid having the functional group (a) that constitutes the polyester (A1) include (meth)acrylic acid.
In addition, in this application, the notation of "(meth)acrylic" means "acrylic" and/or "methacrylic", and the notation of "(meth)acrylate" means "acrylate" and/or "methacrylate".

As the method for producing the polyester (A1), the ester having the hydroxy group and the carboxylic acid having the functional group (a) are charged at a predetermined molar ratio, the reaction temperature is 100 to 250° C., and the pressure is −0. A method of distilling off water while stirring at 1 to 1.2 MPa can be mentioned.
When producing the polyester (A1), it is preferable to add the catalyst in an amount of 0.05 to 0.5% by weight based on the weight of the polyester (A1). As the catalyst, the catalyst exemplified in the explanation of the ester having a hydroxy group can be used, and the preferable ones are also the same.

Examples of the polyisocyanate (γ) constituting the polyester (A2) include aliphatic polyisocyanate (γ1) and aromatic polyisocyanate (γ2).
As the aliphatic polyisocyanate (γ1), a chain aliphatic polyisocyanate having 4 to 20 carbon atoms (ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, octamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, etc.) And alicyclic polyisocyanates having 8 to 20 carbon atoms (such as isophorone diisocyanate and dicyclohexylmethane diisocyanate).
Examples of the aromatic polyisocyanate (γ2) include aromatic polyisocyanates having 8 to 20 carbon atoms (phenylene diisocyanate, diphenylmethane diisocyanate, tolylene diisocyanate, etc.) and the like.

Examples of the compound having a functional group (a) and a hydroxyl group forming the polyester (A2) include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate and 3-hydroxypropyl (meth)acrylate. Can be mentioned.

As the method for producing the polyester (A2), the above-mentioned ester having a hydroxy group and the polyisocyanate (γ) are charged in a predetermined molar ratio, and a urethanization reaction is carried out at a reaction temperature of 0 to 150° C. to obtain an isocyanate. After obtaining the compound, a method of subjecting the compound having a functional group (a) and a hydroxyl group to a urethanization reaction may be mentioned.
In each of the above urethanization reactions, it is preferable to add a catalyst in an amount of 0 to 1% by weight based on the weight of the polyester (A2). Examples of the catalyst include metal compounds (organic bismuth compounds, organic tin compounds, organic titanium compounds, etc.), quaternary ammonium salts, and the like.

The number (m) of the functional groups (a) contained in one molecule of the polyester (A) is 1 to 6. When m exceeds 6, the fiber-opening property deteriorates. In addition, from the viewpoint of adhesiveness with the matrix resin and openability, m is preferably 2 to 4.
Further, from the viewpoint of further improving the fiber-opening property, the number average value (m _A ) per molecule of m in all polyesters (A) contained in the fiber sizing agent of the present invention is 1.0 to 5 It is preferably 0.8.

The number of ester groups contained in one molecule of the polyester (A) is m+1 or more.
When the number of ester groups contained in one molecule of polyester (A) is less than m+1, the adhesiveness with the matrix resin deteriorates. From the viewpoint of sizing property and fiber-opening property, the number of ester groups contained in one molecule of polyester (A) is preferably m+2 to m+12.
From the viewpoint of further improving the adhesion to the matrix resin, the number average per molecule of the number of all polyester (A) has ester groups contained in the fiber sizing agent of the present invention, m _A It is preferably +1.0 or more.
Further, the ratio of the number of ester groups in one molecule of the polyester (A) to m [the number of ester groups/m] is 1.3 to 12 from the viewpoint of improving the adhesiveness with the matrix resin. Preferably, it is more preferably 1.5 to 6.0.

The glass transition temperature of the polyester (A) is preferably 0° C. or lower from the viewpoint of focusing property. When two or more polyesters (A) are used in combination, the glass transition temperature of each polyester is preferably 0°C or lower.
In the present invention, the glass transition temperature can be measured according to the DSC method described in JIS K7121 (1987) using "Differential scanning calorimeter ModelRDC220" manufactured by Seiko Instruments Inc.

The fiber sizing agent of the present invention preferably contains at least one compound (B) selected from the group consisting of a compound having an epoxy group, a polyurethane resin and a polyvinyl resin.

Examples of the compound having an epoxy group include compounds having one or two or more epoxy groups in one molecule, and specific examples thereof include glycidyl ether, glycidyl ester, diglycidyl amine and alicyclic diepoxide. Etc.

Examples of the glycidyl ether include diglycidyl ether of dihydric phenol, glycidyl ether of monohydric alcohol and diglycidyl ether of dihydric alcohol.

Examples of diglycidyl ethers of dihydric phenols include condensates (including polycondensates) of dihydric phenols having 6 to 30 carbon atoms and epichlorohydrin, both ends of which are diglycidyl ethers. Examples of the divalent phenol having 6 to 30 carbon atoms include bisphenol (bisphenol F, bisphenol A, bisphenol B, bisphenol AD, bisphenol S and halogenated bisphenol A), catechin, resorcinol, hydroquinone, 1,5-dihydroxynaphthalene, dihydroxy. Biphenyl, octachloro-4,4'-dihydroxybiphenyl, tetramethylbiphenyl, 9,9'-bis(4-hydroxyphenyl)fluorene and the like can be mentioned.

Examples of glycidyl ethers of monohydric alcohols include condensates (including polycondensates) of monohydric alcohols having 1 to 30 carbon atoms and epichlorohydrin, the ends of which are glycidyl ethers. Examples of the monohydric alcohol having 1 to 30 carbon atoms include methanol, ethanol, butanol, hexanol, cyclohexanol, octanol, dodecyl alcohol, tetradecyl alcohol, stearyl alcohol, icosyl alcohol, behenyl alcohol, tetracosyl alcohol and triacontyl alcohol. Etc.

Examples of the diglycidyl ether of a dihydric alcohol include a condensate (including a polycondensate) of a dihydric alcohol having 2 to 100 carbon atoms and epichlorohydrin, the end of which is diglycidyl ether. As the dihydric alcohol having 2 to 100 carbon atoms, ethylene glycol, propylene glycol, tetramethylene glycol, 1,6-hexanediol, neopentyl glycol, and a number average molecular weight (hereinafter abbreviated as Mn) of 106 to 1932. Examples thereof include polyethylene glycol, polypropylene glycol having Mn=134 to 5818, polytetramethylene ether glycol having Mn=162 to 1818, and an alkylene oxide (1 to 21 mol) adduct of bisphenol A having 2 to 4 carbon atoms.

Examples of the diglycidyl ester include a diglycidyl ester of an aromatic dicarboxylic acid having 8 to 20 carbon atoms and a diglycidyl ester of an aliphatic dicarboxylic acid having 2 to 20 carbon atoms.

The diglycidyl ester of an aromatic dicarboxylic acid having 8 to 20 carbon atoms is a condensate (including a polycondensate) of an aromatic dicarboxylic acid having 8 to 20 carbon atoms and epichlorohydrin, and has two glycidyl groups. The thing etc. are mentioned. Examples of the aromatic dicarboxylic acid having 8 to 20 carbon atoms include phthalic acid, isophthalic acid, terephthalic acid, phenylmalonic acid, homophthalic acid, phenylsuccinic acid, phenylglutaric acid, phenyladipic acid, biphenyldicarboxylic acid and naphthalenedicarboxylic acid. Can be mentioned.

The diglycidyl ester of an aliphatic dicarboxylic acid having 2 to 20 carbon atoms is a condensate (including a polycondensate) of an aliphatic dicarboxylic acid having 2 to 20 carbon atoms and epichlorohydrin, and has two glycidyl groups. The thing etc. are mentioned. Examples of the aliphatic dicarboxylic acid having 2 to 20 carbon atoms include oxalic acid, fumaric acid, maleic acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanenic acid, tetradecanoic acid, Hexadecanoic acid, octadecanoic acid, and icosanninic acid are mentioned.

Examples of the diglycidyl amine include N-glycidyl compounds (N,N-diglycidylaniline and N,N) obtained by reacting an aromatic amine having 6 to 20 carbon atoms and having 2 to 4 active hydrogen atoms with epichlorohydrin. -Diglycidyl toluidine, etc.) and the like. Examples of the aromatic amine having 6 to 20 carbon atoms and 2 to 4 active hydrogen atoms include aniline, phenylenediamine, tolylenediamine and toluidine.

Examples of the alicyclic diepoxide include alicyclic epoxide having 6 to 50 carbon atoms and two epoxy groups [vinylcyclohexene dioxide, limonene dioxide, dicyclopentadiene dioxide, bis(2,3-epoxycyclopentyl) ether. , Ethylene glycol bisepoxydicyclopentyl ether, bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate, bis(3,4-epoxy-6-methylcyclohexylmethyl)butylamine and the like] and the like.

Examples of the polyurethane resin include those derived from a polyol, an organic diisocyanate, and optionally a chain extender and/or a crosslinking agent.

Examples of the polyol include polyester polyols (polyethylene adipate diol, polybutylene adipate diol, polyethylene butylene adipate diol, polyneopentyl adipate diol, polyneopentyl terephthalate diol, polycaprolactone diol, polyvalerolactone diol, polyhexamethylene carbonate diol, etc.) And polyether polyols (polyethylene glycol, polypropylene glycol, polyethylene propylene glycol, polytetramethylene glycol, alkylene oxide adducts of bisphenols having 2 to 4 carbon atoms, etc.) and the like.
The number average molecular weight of the polyol is preferably 40 to 4000.

Specific examples of the organic diisocyanate include aromatic diisocyanates having 8 to 30 carbon atoms [2,4'- or 4,4'-diphenylmethane diisocyanate (MDI), 2,4- or 2,6-tolylene diisocyanate (TDI). ), 4,4'-dibenzyl diisocyanate, 1,3- or 1,4-phenylene diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, etc.]; Aliphatic diisocyanate having 4 to 30 carbon atoms [ethylene diisocyanate, Hexamethylene diisocyanate (HDI), lysine diisocyanate and the like]; alicyclic diisocyanate having 6 to 30 carbon atoms [isophorone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate and the like]; and a mixture of two or more thereof. Be done.

Examples of the polyvinyl resin include polyolefin resins (polyethylene, polypropylene, ethylene-vinyl acetate copolymers and ethylene-ethyl acrylate copolymers), poly(meth)acrylic resins (polymethylmethacrylate, polyacrylic acid and the like). Styrene), polystyrene resin (polystyrene, styrene/acrylonitrile copolymer, styrene/alkyl acrylate copolymer, acrylonitrile/butadiene/styrene copolymer, methyl methacrylate/butadiene/styrene copolymer and styrene/methacrylic acid) Methyl copolymer, etc.) and the like.

The glass transition temperature of the compound (B) is preferably 10° C. or lower from the viewpoint of focusing property. When two or more compounds (B) are used in combination, the glass transition temperature of each compound (B) is preferably 0° C. or lower.

The fiber sizing agent of the present invention may contain a polyester resin other than (A). Examples of the polyester resin other than (A) include esterification products of the above-mentioned carboxylic acid (α) with a polycarboxylic acid and the above-mentioned diol (β).

The fiber sizing agent of the present invention may contain a surfactant (E) and other additives in addition to the polyester resin other than the above polyester (A), compound (B) and (A). good.

As the surfactant (E), known surfactants such as nonionic surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants (Japanese Patent Laid-Open No. 2006-124877, and International Publication No. Those described in 2003/37964) and the like.
As the surfactant (E), one type may be used alone, or two or more types may be used in combination.
Specific examples of the surfactant (E) include the following compounds.
Alkylenephenol alkylene oxide (hereinafter, “alkylene oxide” may be abbreviated as “AO”) adduct (Mn500 to 5,000), arylalkylphenol {styrenated phenol (carbon number 14 to 62), styrenated cumyl. Sulfate ester salt of AO adduct (Mn500 to 5,000) of phenol and styrenated cresol (C15 to C61), alkylphenol (C10 to C20) (Mn500 to 5,000) ( AO addition of sodium salt, potassium salt, ammonium salt, alkanolamine salt, etc.), arylalkylphenol {styrenated phenol (C14-62), styrenated cumylphenol, styrenated cresol (C15-61), etc.) (Mn500 to 5,000) sulfate ester salts and the like.
In addition, in the surfactant (E), AO addition means ethylene oxide (hereinafter, “ethylene oxide” may be abbreviated as “EO”) alone addition, and propylene oxide (hereinafter, “propylene oxide”). Examples thereof include at least one of “PO” and butylene oxide (hereinafter, “butylene oxide” may be abbreviated as “BO”) and EO. When at least one of PO and BO is included, a random adduct, a block adduct, and a mixed adduct thereof are included.
The method of measuring Mn of the surfactant (E) is the same as the method of measuring Mn of the polyester described in the polyester (A).

Among the surfactants (E), anionic surfactants and nonionic surfactants are preferable, more preferably an AO adduct of an alkylphenol having a Mn of 3,000 or less and a melting point of less than 25° C. and a Mn of 3,000 or less and a melting point of 25. AO adduct of arylalkylphenol having a Mn of 3,000 or less and melting point of less than 25°C, sulfuric acid ester salt of AO adduct of alkylphenol having a Mn of 3,000 or less and melting point of less than 25°C Ester salts and mixtures thereof, particularly preferably AO (EO and PO) adducts of arylalkylphenols having a Mn of 3,000 or less and a melting point of less than 25° C. and AO (EO and EO of arylalkylphenols having a Mn of 3,000 or less and a melting point of less than 25° C. And PO) adducts of sulfuric acid ester salts and mixtures thereof.

Examples of other additives include a leveling agent, a preservative and an antioxidant.
Examples of the leveling agent include wax (polyethylene, polypropylene, oxidized polyethylene, oxidized polypropylene, modified polyethylene, modified polypropylene, etc.), higher fatty acid (fatty acid having 6 to 30 carbon atoms) alkyl (alkyl having 1 to 24 carbon atoms) ester (methyl stearate). Rate, ethyl stearate, propyl stearate, butyl stearate, octyl stearate, stearyl stearate, etc.), higher fatty acids (fatty acid having 6 to 30 carbon atoms) (myristic acid, palmitic acid, stearic acid, etc.), natural fats and oils ( Palm oil, beef tallow, olive oil, rapeseed oil, etc.) and liquid paraffin.
Examples of antiseptics include benzoic acid, salicylic acid, sorbic acid, quaternary ammonium salts, imidazole and the like.
As the antioxidant, phenol (2,6-di-t-butyl-p-cresol etc.), thiodipropionate (dilauryl 3,3′-thiodipropionate etc.) and phosphite (triphenylphosphite etc.) ) And the like.

The contents of the polyester (A), the compound (B), the polyester resin other than (A), the surfactant (E) and other additives in the fiber sizing agent of the present invention are as follows.
The weight ratio of (A) is preferably 1 to 90% by weight, more preferably 5 to 80% by weight based on the weight of the solid content contained in the fiber sizing agent from the viewpoint of adhesiveness to the matrix resin and fiber-spreading property. %, particularly preferably 10 to 75% by weight.
The weight ratio of (B) is preferably 1 to 90% by weight, more preferably 5 to 80% by weight, particularly preferably 5 to 80% by weight, based on the weight of the solid content contained in the fiber sizing agent, from the viewpoint of adhesiveness to the matrix resin. It is preferably 10 to 75% by weight.
From the viewpoint of emulsion stability, the weight ratio of the polyester resin other than (A) is preferably 0 to 90% by weight, more preferably 10 to 70% by weight, based on the weight of the solid content contained in the fiber sizing agent. is there.
From the viewpoint of emulsion stability, the weight ratio of the surfactant (E) is preferably 0.1 to 40% by weight, more preferably 0.5 to 35, based on the weight of the solid content contained in the fiber sizing agent. %, particularly preferably 1 to 30% by weight.
From the viewpoint of fluidity and stability over time, the weight ratio of the leveling agent, the preservative, and the antioxidant as other additives is preferably 0.01 to, based on the weight of the solid content contained in the fiber sizing agent. It is 20% by weight, more preferably 0.05 to 15% by weight, and particularly preferably 0.1 to 10% by weight.
Here, the solid content is a residue obtained by heating and drying 1 g of the sample at 130° C. for 45 minutes with a circulating air dryer.

The weight ratio [(A)/(B)] of the polyester (A) to the compound (B) is preferably 10/90 to 90/10, more preferably 20/80, from the viewpoint of adhesiveness. ~80/20.

From the viewpoint of sizing property, the fiber sizing agent of the present invention has a weight ratio of solids having a glass transition temperature of 0° C. or less of 50, based on the weight of all solids. % Or more, and more preferably 80% by weight or more.

The fiber sizing agent of the present invention preferably contains an aqueous medium so as to be in the form of an aqueous solution or an aqueous emulsion.
When the aqueous medium is contained, it is easy to make the amount of the solid content contained in the fiber sizing agent adhered to the fibers, so that a fiber bundle having further excellent strength when formed into a molded product can be obtained.
As the aqueous medium, a known aqueous medium or the like can be used, and specifically, water and a hydrophilic organic solvent [monohydric alcohol having 1 to 4 carbon atoms (methanol, ethanol and isopropanol, etc.), 3 carbon atoms] To 6 ketones (acetone, ethyl methyl ketone, methyl isobutyl ketone, etc.), glycols having 2 to 6 carbon atoms (ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, etc.) and their monoalkyl (1 to 2 carbon atoms) ethers. , Dimethylformamide, and alkyl acetates having 3 to 5 carbon atoms (such as methyl acetate and ethyl acetate)].
You may use together 2 or more types of these. Among these, water and a mixed solvent of a hydrophilic organic solvent and water are preferable from the viewpoint of safety and the like, and water is more preferable.

From the viewpoint of cost and the like, the fiber sizing agent of the present invention preferably has a high concentration during distribution and a low concentration during production of the fiber bundle. That is, by distributing the resin at a high concentration, transportation costs and storage costs can be reduced, and by treating the fibers at a low concentration, it is possible to manufacture a fiber bundle that gives excellent molded body strength.
The concentration of the high-concentration aqueous solution or aqueous emulsion (weight ratio of the solid content to the fiber sizing agent) is preferably 20 to 80% by weight, more preferably 30 to 70% by weight, from the viewpoint of storage stability and the like. ..
On the other hand, the concentration of the low-concentration aqueous solution or aqueous emulsion (the weight ratio of the solid content to the fiber sizing agent) is preferably 0.5 to 5 from the viewpoint of adjusting the amount of the sizing agent attached during the production of the fiber bundle. It is 15% by weight, more preferably 1 to 10% by weight.

The sizing agent for fibers of the present invention includes the polyester (A) and, if necessary, the compound (B), a polyester resin other than (A), a surfactant (E), other additives and an aqueous medium. Can be mixed and manufactured.
It can be produced by mixing the above components in any order, but preferably, the components other than the aqueous medium are mixed in advance, and the resulting mixture is added with an aqueous medium to dissolve or emulsify and disperse. Is.

The temperature in the case of mixing the components other than the aqueous medium in advance is preferably 20 to 90°C, more preferably 40 to 90°C from the viewpoint of easy mixing, and the temperature of the subsequent dissolution or emulsion dispersion is also the same. is there.
The dissolution or emulsion dispersion time is preferably 1 to 20 hours, more preferably 2 to 10 hours.

There is no limitation on the mixing device, the dissolving device and the emulsifying/dispersing device, and stirring blades (blade shape: chi-type and three-stage paddle etc.), Nauter mixer, ribbon mixer, conical blender, mortar mixer, universal mixer (universal mixing agitator 5DM -L, manufactured by Sanei Seisakusho Co., Ltd.) and Henschel mixer can be used.

As the fiber to which the fiber sizing agent of the present invention can be applied, known fibers such as carbon fiber, glass fiber, aramid fiber, ceramic fiber, metal fiber, mineral fiber and slug fiber (described in WO2003/47830). Etc.) and the like, and from the viewpoint of the strength of the molded body, carbon fiber is preferable. Two or more kinds of these fibers may be used in combination.

The fiber bundle of the present invention is obtained by treating at least one fiber selected from the group consisting of these fibers with the above-mentioned fiber sizing agent.
The fiber bundle of the present invention is preferably a bundle of about 3,000 to 30,000 fibers.

Examples of the fiber treatment method include a spray method and a dipping method. The amount (% by weight) of the solid content contained in the sizing agent for fibers to the fibers is preferably 0.05 to 5% by weight, more preferably 0.2 to 2.5% by weight, based on the weight of the fibers. Is. Within this range, the strength of the molded product will be even better.

A fiber product of the present invention is a fiber product obtained by processing the fiber bundle, and contains the fiber bundle of the invention and a matrix resin. The textile product of the present invention may optionally contain a catalyst.
The above-mentioned fiber products include woven fabrics, knitted fabrics, non-woven fabrics (such as felt, mat and paper), chopped fibers and milled fibers.

As the matrix resin, thermoplastic resins (polypropylene, polyamide, polyethylene terephthalate, polycarbonate, polyphenylene sulfide, etc.) and thermosetting resins [compounds having the above-mentioned epoxy group, unsaturated polyester resins (such as those described in Japanese Patent No. 3723462, etc. ), the above-mentioned vinyl ester resin and phenol resin (such as those described in Japanese Patent No. 3723462)] and the like.

Examples of the catalyst for the compound having an epoxy group include known curing agents for epoxy resins (such as those described in JP-A-2005-213337) and curing accelerators. Further, as a catalyst for unsaturated polyester resin and vinyl ester resin, peroxides (benzoyl peroxide, t-butyl perbenzoate, t-butyl cumyl peroxide, methyl ethyl ketone peroxide, 1,1-di(t- Butyl peroxy)butane, di(4-t-butylcyclohexyl)peroxy dicarbonate, etc., and azo compounds (azobisisovaleronitrile, etc.) and the like.

In the fiber product of the present invention, the weight ratio of the matrix resin and the fiber bundle (matrix resin/fiber bundle) is preferably 10/90 to 90/10, and more preferably 20/90 from the viewpoint of the strength of the molded body. It is 80 to 70/30, and particularly preferably 30/70 to 60/40. When the fiber product contains a catalyst, the content of the catalyst is preferably 0.01 to 10% by weight, and more preferably 0.1 to 5% by weight with respect to the matrix resin from the viewpoint of the strength of the molded body. And particularly preferably 1 to 3% by weight.

For fiber products, fiber bundles are impregnated with a matrix resin that is heat-melted (preferred melting temperature: 60 to 350° C.) or diluted with a solvent (acetone, methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, ethyl acetate, etc.). Can be manufactured. When a solvent is used, it is preferable to dry the prepreg to remove the solvent.

By molding the fiber product of the present invention, a fiber-reinforced composite material is obtained. When the matrix resin is a thermoplastic resin, a molded product can be obtained by heat-molding the prepreg and solidifying at room temperature. When the matrix resin is a thermosetting resin, the prepreg can be heat-molded and cured to form a molded body. The curing does not have to be completed, but it is preferable that the molded body is cured to such an extent that the shape can be maintained. After molding, it may be further heated to be completely cured.
The method of heat molding is not particularly limited, and includes filament winding molding method (a method in which a rotating mandrel is wound while applying tension and heat molding), press molding method (a method in which prepreg sheets are laminated and heat molded), and an autoclave method ( Examples of the method include heat-molding by pressing a prepreg sheet against a mold) and a method of mixing chopped fibers or milled fibers with a matrix resin and injection-molding.

Hereinafter, the present invention will be further described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Hereinafter, unless otherwise specified,% means% by weight and part means part by weight.

The glass transition temperatures of polyesters (A-1) to (A-7) and comparative polyesters (A'-1) to (A'-4) and (B-1) to (B-3) are Seiko Instruments. It was measured according to the DSC method described in JIS K7121 (1987) using "Differential Scanning Calorimeter Model RDC220" manufactured by the same company.

Production Example 1 <Production of Polyester (A-1)>
EO2 mol adduct of bisphenol A "Newpol BPE-20" [manufactured by Sanyo Kasei Co., Ltd.] 316 parts (1 mol part), 77.7 parts fumaric acid (0.67 mol part) and potassium oxalate titanate. After reacting 4 parts in a glass reaction container at 230° C. under reduced pressure to 0.001 MPa for 15 hours while distilling off water, 10 parts of paratoluenesulfonic acid, 200 parts of toluene, 2 parts of hydroquinone and 48 parts of acrylic acid. 0.7 parts (0.677 parts by mole) was added, the pressure was reduced to 0.04 MPa at 90° C. while ventilating the air, water was distilled off, and the reaction was continued until the hydroxyl value became 1.0 or less, then to 25° C. Cooled. Further, 200 parts of toluene and 200 parts of a 10% sodium hydroxide aqueous solution are added for liquid separation, the lower aqueous layer is distilled off, and then the pressure is reduced to 0.01 MPa at 90° C. to distill off the toluene, m=2, the number of ester groups Polyester (A-1) of 6 was obtained. The glass transition temperature of polyester (A-1) was 0°C or lower.

Production Example 2 <Production of Polyester (A-2)>
In Production Example 1, 77.7 parts (0.67 mol part) of fumaric acid was added to 87.0 parts (0.75 mol part), and 48.7 parts (0.677 mol part) of acrylic acid was 36.4 parts. A polyester (A-2) having m=2 and 8 ester groups was obtained in the same manner as in Production Example 1 except that the amount was changed to (0.505 mol part). The glass transition temperature of the polyester (A-2) was 0°C or lower.

Production Example 3 <Production of Polyester (A-3)>
In Production Example 1, 316 parts (1 part by mol) of EO2 mol adduct of bisphenol A was added to diethylene glycol 212 (2 parts by mol), and 77.7 parts (0.67 parts by mol) of fumaric acid was added to terephthalic acid 222.4 (1). .34 mol parts) and acrylic acid 48.7 parts (0.677 mol parts) were changed to 97.2 parts (1.35 mol parts) in the same manner as in Production Example 1, m=2, and the number of ester groups was changed. Polyester (A-3) of 6 was obtained. The glass transition temperature of the polyester (A-3) was 0°C or lower.

Production Example 4 <Production of Polyester (A-4)>
In Production Example 1, 316 parts (1 part by mole) of EO2 mole adduct of bisphenol A was added to EO10 moles of bisphenol A "Newpol BPE-100" [manufactured by Sanyo Chemical Industry Co., Ltd.] 334 (0.5 mole part). ), fumaric acid 77.7 parts (0.67 parts by mole) to terephthalic acid 41.5 (0.25 parts by mole), and acrylic acid 48.7 parts (0.677 parts by mole) to 36.4 parts ( Polyester (A-4) having m=2 and 4 ester groups was obtained in the same manner as in Production Example 1 except that the amount was changed to 0.505 mol part). The glass transition temperature of polyester (A-4) was 0°C or lower.

Production Example 5 <Production of Polyester (A-5)>
EO2 mol adduct of bisphenol A "Newpol BPE-20" [manufactured by Sanyo Kasei Co., Ltd.] 316 parts (1 mol part), fumaric acid 77.7 parts (0.67 mol part) and potassium oxalate titanate. An esterified product (number of ester groups: 4) was obtained by reacting 4 parts in a glass reaction vessel at 230°C under reduced pressure to 0.001 MPa for 15 hours while distilling off water. 122 parts (0.1 mol part) of this esterified product, trifunctional isocyanate "Duranate 24A-100" [burette modified product of hexamethylene diisocyanate, manufactured by Asahi Kasei Corporation] 108 parts (0.202 mol part), bismuth as a catalyst 1 part of a 50% solution of 2-ethylhexanoic acid of tris(2-ethylhexanoate) was charged, the mixture was stirred and homogenized, and then reacted at 80° C. for 6 hours. Further, 2 parts of hydroquinone and 46.4 parts (0.4 mol part) of 2-hydroxyethyl acrylate were added, and the mixture was reacted at 75° C. while aeration of air until the isocyanate content became 0.01% or less, m=4, A polyester (A-5) having 8 ester groups was obtained. The glass transition temperature of polyester (A-5) was 0°C or lower.

Production Example 6 <Production of Polyester (A-6)>
Manufacturing Example 1 was repeated except that 48.7 parts (0.677 mol part) of acrylic acid was changed to 24.4 parts (0.338 mol part), and m=1 and the number of ester groups was 5. Polyester (A-6) was obtained. The glass transition temperature of polyester (A-6) was 0°C or lower.

Production Example 7 <Production of Polyester (A-7)>
The same procedure as in Production Example 1 except that 48.7 parts (0.677 mole parts) of acrylic acid was changed to 58.2 parts (0.677 mole parts) of methacrylic acid, and m=2, the number of ester groups was changed. A polyester (A-7) of 6 was obtained. The glass transition temperature of polyester (A-7) was 0°C or lower.

Comparative Production Example 1 <Production of Polyester (A′-1)>
EO2 mol addition product of bisphenol A "Newpol BPE-20" [manufactured by Sanyo Chemical Industries, Ltd.] 316 parts (1 mol part), paratoluenesulfonic acid 10 parts, toluene 200 parts, hydroquinone 2 parts and acrylic acid 145 parts (2.02 parts by mole) was added, the pressure was reduced to 0.04 MPa at 90° C. while ventilating air, the reaction was carried out while distilling water off until the hydroxyl value became 1.0 or less, and then cooled to 25° C. Further, 200 parts of toluene and 200 parts of a 10% sodium hydroxide aqueous solution are added for liquid separation, the lower aqueous layer is distilled off, and then the pressure is reduced to 0.01 MPa at 90° C. to distill off the toluene, m=2, the number of ester groups 2 polyester (A'-1) was obtained. The glass transition temperature of the polyester (A′-1) was 0° C. or lower.

Comparative Production Example 2 <Production of Polyester (A′-2)>
Comparative Comparative Example 1 was the same as Comparative Example 1 except that 145 parts (2.02 parts by mole) of acrylic acid was changed to 72.7 parts (1.01 parts by mole), and m=1 and the number of ester groups was 1. Polyester (A'-2) was obtained. The glass transition temperature of the polyester (A′-2) was 0° C. or lower.

Comparative Production Example 3 <Production of Polyester (A′-3)>
134 parts of trimethylolpropane (1 mol part), 7 parts of paratoluenesulfonic acid, 200 parts of toluene, 2 parts of hydroquinone and 145 parts of acrylic acid (2.02 parts by mol) were added thereto, and at 0. The pressure was reduced to 04 MPa, the water was distilled off, the reaction was carried out until the hydroxyl value reached 420, and the mixture was cooled to 25°C. Further, 200 parts of toluene and 200 parts of 10% sodium hydroxide aqueous solution are added for liquid separation, the lower aqueous layer is distilled off, and the pressure is reduced to 0.01 MPa at 90° C. to distill off toluene, followed by column chromatography (elution). Liquid: dichloromethane/acetone=97/3) for purification, and trimethylolpropane diacrylate was collected.
Then, in another glass-made reaction container, 316 parts (1 mol part) of EO2 mol addition product of bisphenol A "New Pole BPE-20" [manufactured by Sanyo Chemical Industry Co., Ltd.] and 77.7 parts of fumaric acid (0. 67 parts by mole) and 4 parts of potassium oxalate titanate were added, and the reaction mixture was allowed to react for 15 hours while reducing the pressure to 0.001 MPa at 230° C. and distilling water to obtain an esterified product (ester group number 4).
122 parts (0.1 mol part) of this esterified product, 108 parts (0.202 mol part) of trifunctional isocyanate "Duranate 24A-100" [manufactured by Asahi Kasei Corporation], and bismuth tris(2-ethylhexanoate) as a catalyst. 1 part of a 50% solution of 2-ethylhexanoic acid was charged and homogenized with stirring, and after reacting at 80° C. for 6 hours, 2 parts of hydroquinone and 96.8 parts of trimethylolpropane diacrylate (0.4 mol part) ) Was added, and the mixture was reacted at 75° C. while ventilating air until the isocyanate content became 0.01% or less to obtain a polyester (A′-3) having m=8 and 12 ester groups. The glass transition temperature of polyester (A′-3) was 0° C. or lower.

Comparative Production Example 4 <Production of polyester (A′-4)>
In Production Example 1, 316 parts (1 part by mol) of an EO2 mol adduct of bisphenol A was added to 212 (2 parts by mol) of diethylene glycol, and 77.7 parts (0.67 parts by mol) of fumaric acid was added to 155.4 (1.34 parts). (Mole part), except that acrylic acid 48.7 parts (0.677 part by mole) was changed to 97.2 parts (1.35 parts by mole), the same procedure as in Production Example 1 was repeated except that m=2 and the number of ester groups was 6 A polyester (A′-4) having no aromatic ring was obtained. The glass transition temperature of the polyester (A′-4) was 0° C. or lower.

<Examples 1 to 10 and Comparative Examples 1 to 5>
Except for water, the raw materials of the number shown in Table 1 were uniformly dissolved for 30 minutes in a universal mixer [universal mixing stirrer (manufactured by Sanei Seisakusho Co., Ltd.)] while controlling the temperature at 60°C, and then water was added thereto. The fiber sizing agents (C-1) to (C-10) of the present invention having a water dispersion concentration of 40% by weight and the comparative fiber sizing agents (C'-1) to (C) were added dropwise over 6 hours. 2500 parts of each of'-5) were obtained.

The chemical compositions of the raw materials with the symbols shown in Table 1 are as follows.
(B-1): Compound having epoxy group [condensation product of diglycidyl ether of bisphenol A and epichlorohydrin, trade name "JER1001", manufactured by Mitsubishi Chemical Corporation, (B-1) glass transition temperature: 10°C Less than]
(B-2): solution containing polyurethane resin [solution containing polycarbonate polyurethane resin emulsion (solid content concentration: 50% by mass), trade name "Permarin UA-368", manufactured by Sanyo Chemical Industries, Ltd., ( Glass transition temperature of B-2): 10° C. or lower]
(B-3): solution containing polyacrylic resin [solution containing sodium polyacrylate (solid content concentration: 43% by mass), trade name "Aron T-50", manufactured by Toagosei Co., Ltd., (B -3) glass transition temperature: 10°C or lower]
(E-1): Propylene oxide ethylene oxide adduct of styrenated phenol [trade name "Soprophor 796/P", manufactured by Solvay Nika Co., Ltd.]

Using the sizing agents for fibers of Examples and Comparative Examples, the sizing properties, fiber-opening properties and adhesive properties of carbon fiber bundles were evaluated by the following evaluation methods.

<Evaluation of focusing property>
(1) Immersing untreated carbon fibers (fineness: 800 tex, number of filaments: 12,000) in an aqueous solution obtained by further diluting the fiber sizing composition with a solid content concentration of 1.5% by weight. A sizing agent was impregnated and dried with hot air at 180° C. for 3 minutes to prepare a carbon fiber bundle.
(2) The bundling property of the obtained carbon fiber bundle was evaluated according to JIS L1096-2010 8.21.1 A method (45° cantilever method).
The larger the value (cm), the better the focusing property.
In general, the carbon fiber bundle obtained under these treatment conditions has a focusing property evaluated by a cantilever of 13 cm or more.

<Evaluation of openability>
Five stainless steel rods with a smooth surface heated to 70°C and having a diameter of 10 mm are arranged in parallel so that the horizontal spacing between the stainless steel rods is 50 mm, and the carbon fiber bundle is in zigzag while contacting the stainless steel rod. It was placed so that it would pass (Fig. 1). The straight line connecting the centers of the stainless steel rods through which the carbon fiber bundle passes first, third and fifth, and the straight line connecting the centers of the stainless steel rods through which the carbon fiber bundle passes second and fourth intersect with the horizontal plane. Arranged to be parallel. In addition, before and after passing the second to fourth stainless rods, a straight line that is the traveling direction of the carbon fiber bundle before passing and a straight line that is the traveling direction of the carbon fiber bundle after passing have an angle of 120 degrees. As it is (for example, a straight line that is the traveling direction of the carbon fiber bundle that passes between the first and second stainless rods and a carbon fiber bundle that passes between the second and third stainless rods). And a straight line which is the traveling direction of () make an angle of 120 degrees.
A carbon fiber bundle treated with each sizing agent was zigzag-between the stainless rods, and the carbon fiber bundle was transferred from the unwinding roll to the winding roll at a tension of 1000 g between the winding roll and the unwinding roll at a speed of 3 m/min. The spread width (mm) of the carbon fiber bundle after winding and passing through five stainless steel bars was measured {using a yarn running test device manufactured by Asano Machinery Co., Ltd.}.
Generally, the spread width of the carbon fiber bundle measured under these conditions is preferably 8 mm or more.

<Adhesion evaluation>
Adhesion was evaluated by the microdroplet method.
(1) A carbon fiber filament was taken out from the carbon fiber bundle obtained by the above method and set in a sample holder.
(2) A microdroplet of a matrix resin composed of 100 parts by weight of a vinyl ester resin "Lipoxy R-804" [manufactured by Showa Denko KK] and 25 parts by weight of a curing agent "Permec N" [manufactured by NOF CORPORATION]. It was formed on a carbon fiber filament, heated at 25° C. for 24 hours and heated at 120° C. for 5 hours to be cured to obtain a sample for measuring the adhesiveness.
(3) The measurement sample was set in the composite material interface characteristic evaluation device HM410 [manufactured by Toei Sangyo Co., Ltd.], and the maximum pulling load F when pulling out the microdroplets from the carbon fiber filament was measured.
(4) The interfacial shear strength τ was calculated by the following formula.
Interfacial shear strength τ (unit: MPa)=F/πdL
[However, F represents the maximum drawing load (N), d represents the carbon fiber filament diameter (μm), and L represents the particle size (μm) in the drawing direction of the microdroplets. ]
The larger the interfacial shear strength τ, the higher the adhesiveness, and in general, 45 MPa or more is preferable.

The fiber sizing agents of Examples 1 to 10 of the present invention can form a fiber bundle having excellent openability while maintaining a high sizing property, and have excellent adhesiveness between the fiber and the matrix resin. ..
On the other hand, Comparative Examples 1 and 2 having a small number of ester groups have low adhesiveness, and Comparative Example 3 having too many functional groups (a) has a low fiber-opening property.
Further, Comparative Example 4 which does not contain the polyester having an aromatic ring has low bundling property and adhesiveness, and Comparative Example 5 which does not contain the polyester having the functional group (a) has low openability and adhesiveness.

The fiber sizing agent of the present invention can be used as a sizing agent for glass fiber, carbon fiber, aramid fiber, ceramic fiber, metal fiber, mineral fiber or slug fiber.
Further, a prepreg can be obtained by using a fiber bundle or a fiber product obtained by treating with the fiber sizing composition of the present invention as a reinforcing fiber and using a thermoplastic resin or a thermosetting resin as a matrix.

1. Stainless rod 2. Unwinding roll 3. Take-up roll 4. Carbon fiber bundle 5. Opening measurement position

Claims (12)

A sizing agent for fibers, comprising a polyester (A) having an aromatic ring and a functional group (a) represented by the general formula (1),
The number (m) of the functional groups (a) contained in one molecule of the polyester (A) is 1 to 6,
A fiber sizing agent in which the number of ester groups contained in one molecule of the polyester (A) is m+1 or more.

[In the general formula (1), R represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and when the polyester (A) has a plurality of Rs, they may be the same or different. ] The number average value (m _A ) per molecule of m in all polyesters (A) contained in the fiber sizing agent is 1.0 to 5.8, and all polyesters contained in the fiber sizing agent the number average value per molecule of the number of ester groups (a) has found fiber sizing agent according to claim 1 is m _a +1.0 or more. The fiber sizing agent according to claim 1 or 2, wherein the polyester (A) is a polyester containing an aromatic polycarboxylic acid and an aromatic polyol as essential constituent monomers. The sizing agent for fibers according to any one of claims 1 to 3, wherein R in the general formula (1) is a hydrogen atom or a methyl group. The fiber sizing agent according to claim 3 or 4, wherein the aromatic polyol has a bisphenol skeleton. The fiber sizing agent according to claim 3, wherein the aromatic polyol has a polyoxyalkylene chain. The fiber sizing agent according to any one of claims 1 to 6, wherein the polyester (A) has a glass transition temperature of 0°C or lower. Further, the fiber sizing agent according to any one of claims 1 to 7, further comprising at least one compound (B) selected from the group consisting of a compound having an epoxy group, a polyurethane resin and a polyvinyl resin. The sizing agent for fibers according to claim 8, wherein the glass transition temperature of the compound (B) is 10°C or lower. The weight ratio [(A)/(B)] of the polyester (A) and the compound (B) is 10/90 to 90/10, and the fiber sizing agent according to claim 8 or 9. The fiber sizing agent according to any one of claims 1 to 10, wherein at least one fiber selected from the group consisting of carbon fiber, glass fiber, aramid fiber, ceramic fiber, metal fiber, mineral fiber and slug fiber is used. Fiber bundles that have been treated with. A fiber product containing the fiber bundle according to claim 11.

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