JP6535142B2 - Reinforcing fiber sizing agent and use thereof - Google Patents

Description

  The present invention relates to a reinforcing fiber sizing agent and its use. In particular, the present invention relates to a reinforcing fiber sizing agent used to reinforce a matrix resin, a reinforcing fiber strand using the same, a reinforcing fiber chopped strand, and a fiber-reinforced composite material.

  BACKGROUND ART Fiber-reinforced composite materials in which plastic materials (referred to as matrix resins) are reinforced with various synthetic fibers are widely used in automotive applications, aerospace / space applications, sports / leisure applications, general industrial applications, and the like. Examples of fibers used for 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 produced in the form of filaments and then processed into sheet-like intermediate materials called one-way prepregs by the hot melt method, drum winding method, etc., or processed by the filament winding method, and in some cases woven fabrics. Alternatively, it is used as a reinforcing fiber after being subjected to various higher-order processing steps such as being processed into a chopped fiber shape.

Reinforcing fibers are inherently low in elongation, stiffness and brittleness, and are poor in bending resistance and scratch resistance, so fluff is likely to be generated in the manufacturing process and high-order processing process passing through a large number of guide rollers and metal bars. There is a problem that the performance and the quality deteriorate.
In order to prevent these problems, a sizing agent is usually applied to the reinforcing fiber strand, many techniques of applying a sizing agent containing various thermoplastic resins as a main agent for the purpose of bundling reinforcing fiber bundles and suppressing fuzzing It is proposed (refer patent document 1) and is widely used industrially.

  However, in the application of the conventional sizing agent, it has been difficult to simultaneously impart the bundling property of the reinforcing fiber strand and the bundling property of the chopped strand used by cutting the strand. Therefore, when handling a strand or a chopped strand, there existed a case where the production efficiency fall and the physical-property fall of composite material generate | occur | produce by strand breakage | shortage or the feed instability of a chopped strand. Furthermore, with the application of the sizing agent described in the prior art, the adhesion between the matrix resin and the reinforcing fibers may be insufficient, and the properties of the reinforcing fiber composite may not reach satisfactory levels. Development of a sizing agent capable of simultaneously imparting these characteristics has been desired.

Japanese Patent Application Laid-Open No. 6-116868

  In view of such prior art background, an object of the present invention is to provide excellent strand convergence, excellent chopped strand convergence and excellent adhesion to a matrix resin to reinforcing fibers used to reinforce the matrix resin. It is an object of the present invention to provide a sizing agent for reinforcing fibers which can simultaneously be applied, and reinforcing fiber strands, reinforcing fiber chopped strands and fiber reinforced composite materials using the same.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining in order to solve the said subject, the present inventors discover that the said subject can be solved if the sizing agent for reinforcing fibers which contains a specific aromatic polyester-type urethane resin essentially is used, and this invention Reached.
That is, the sizing agent for reinforcing fibers of the present invention essentially contains an aromatic polyester-based urethane resin, and the aromatic polyester-based urethane resin comprises an organic polyisocyanate compound (A) and an active hydrogen group-containing compound (B) The active hydrogen group-containing compound (B) is an aromatic polyester polyol (B1), a tertiary amine compound (B2) having an active hydrogen group, and an active hydrogen group-containing compound (B3) having a carboxyl group. Is required.

  When the constituent unit derived from the aromatic polyester polyol (B1) in the aromatic polyester-based urethane resin is 100 moles, the ratio of the constituent unit derived from the tertiary amine compound (B2) having the active hydrogen group is It is 0.1-1000 mol, and it is preferable that the ratio of the structural unit derived from the active hydrogen group containing compound (B3) which has the said carboxyl group is 0.1-1000 mol.

  When the constituent unit derived from the tertiary amine compound (B2) having the active hydrogen group in the aromatic polyester urethane resin is 100 moles, it is derived from the active hydrogen group-containing compound (B3) having the carboxyl group It is preferable that the ratio of a structural unit is 0.5-20000 mol.

  The active hydrogen group-containing compound (B) is a compound other than the aromatic polyester polyol (B1), the tertiary amine compound (B2) having an active hydrogen group, and the active hydrogen group-containing compound (B3) having a carboxyl group. Preferably, it contains a trifunctional or higher functional hydrogen group-containing compound (B4).

  The tertiary amine compound (B2) having an active hydrogen group is preferably at least one selected from a compound represented by the following general formula (1) and a compound represented by the following general formula (2).

（式（１）中、Ｒ^１は炭素数１〜２０の炭化水素基である。Ａ^１Ｏは炭素数２〜４のオキシアルキレン基である。ａは１〜２０の数である。ｍは０〜２の数である。分子内にＲ^１、（Ａ^１Ｏ）ａが複数ある場合には、お互いに同一であっても異なっていてもよい。）

(In formula (1), R ¹ is a hydrocarbon group having 1 to 20 carbon atoms. A ¹ O is an oxyalkylene group having 2 to 4 carbon atoms. A is a number from 1 to 20. m is It is a number from 0 to 2. When there are a plurality of R ¹ and (A ¹ O) a in the molecule, they may be the same or different from each other.)

（式（２）中、Ｒ^２は炭素数１〜２０の炭化水素基である。Ａ^２は炭素数１〜１０の炭化水素基である。ｎは１〜２の数である。分子内にＲ^２、Ａ^２が複数ある場合には、お互いに同一であっても異なっていてもよい。）

(In the formula (2), R ² is a hydrocarbon group having 1 to 20 carbon atoms. A ² is a hydrocarbon group having 1 to 10 carbon atoms. N is a number from 1 to 2. When there are a plurality of R ² and A ² , they may be identical to or different from each other.)

  The active hydrogen group-containing compound (B) preferably further contains a polyalkylene glycol (B5) having a number average molecular weight of 100 to 2,000.

  Furthermore, it is preferable to contain the polyoxyalkylene alkyl ether (C) which is the alkylene oxide adduct of a C4-C20 monohydric alcohol.

  The reinforcing fiber is preferably carbon fiber.

The reinforcing fiber strand of the present invention is obtained by attaching the above-mentioned reinforcing fiber sizing agent to a raw material reinforcing fiber strand.
The reinforcing fiber chopped strand of the present invention is obtained by cutting a reinforcing fiber strand obtained by adhering the above-described reinforcing fiber sizing agent to a raw material reinforcing fiber strand.

  The fiber-reinforced composite material of the present invention comprises a matrix resin, the above-described reinforcing fiber strand and / or the above-described reinforcing fiber chopped strand.

  The sizing agent for reinforcing fibers of the present invention can simultaneously impart excellent strand bundling properties, excellent chopped strand bundling properties, and excellent adhesiveness with a matrix resin to the reinforcing fibers. The reinforcing fiber strand and the reinforcing fiber chopped strand of the present invention have excellent bundling properties and excellent adhesion to the matrix resin. By using the reinforcing fiber strand or the reinforcing fiber chopped strand of the present invention, a fiber-reinforced composite material having excellent physical properties can be obtained.

  The present invention is a sizing agent for reinforcing fibers used to reinforce a matrix resin, which essentially contains a specific aromatic polyester-based urethane resin. The details will be described below.

[Aromatic polyester-based urethane resin]
The aromatic polyester-based urethane resin, which is an essential component of the sizing agent of the present invention, is a reaction product of the organic polyisocyanate compound (A) and the active hydrogen group-containing compound (B). Polymer component. The active hydrogen group-containing compound (B) contains an aromatic polyester polyol (B1), a tertiary amine compound (B2) having an active hydrogen group, and an active hydrogen group-containing compound (B3) having a carboxyl group. By using such a specific aromatic polyester-based urethane resin as a sizing agent for reinforcing fibers, the bundling ability of reinforcing fiber strands, the bundling ability of reinforcing fiber chopped strands, and the adhesion between reinforcing fibers and matrix resin are dramatically improved. It can be improved.

  The organic polyisocyanate compound (A) is an essential component of the aromatic polyester-based urethane resin, and 2 or more (preferably 2 to 6, more preferably 2 to 3, more preferably 2) in the molecule. Containing the isocyanato group of The organic polyisocyanate compound (A) may be used alone or in combination of two or more.

As an organic polyisocyanate compound (A), aliphatic polyisocyanate, alicyclic polyisocyanate, aromatic polyisocyanate etc. are mentioned.
Examples of aliphatic polyisocyanates include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, 2,2,4- or 2,4,4-trimethyl Hexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethyl caproate, 2,6-diisocyanatoethyl caproate, bis (2-isocyanatoethyl) fumarate and bis (2-isocyanatoethyl) carbonate Diisocyanate; 1,6,11-undecanetriisocyanate, 1,8-diisocyanate-4-isocyanatomethyloctane, 1,3,6-hexacene Tylenetriisocyanate and lysine ester triisocyanate (eg phosgenate of reaction product of lysine and alkanolamine, 2-isocyanatoethyl-2,6-diisocyanatohexanoate and 2- or 3-isocyanatopropyl-2 And trifunctional or higher polyisocyanates such as 6, 6-diisocyanatohexanoate) and the like.

  As an alicyclic polyisocyanate, for example, isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4'-diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, bis (2-isocyanatoethyl) -4 -Diisocyanates such as cyclohexylene-1,2-dicarboxylate and 2,5- or 2,6-norbornane diisocyanate; and trifunctional or higher polyisocyanates such as bicycloheptane triisocyanate; and the like.

  As aromatic polyisocyanate, for example, 3,3'-dimethoxy-4,4'-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, 2,4-tolylene diisocyanate, 2,6 -Tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, phenylene diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate, polymeric 4,4'-diphenylmethane diisocyanate, etc. may be mentioned.

  Among these, ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 4,4'-diphenylmethane Diisocyanate is preferred, and hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, and 4,4'-diphenylmethane diisocyanate are more preferred.

The active hydrogen group-containing compound (B) is an essential component of an aromatic polyester urethane resin, and means a compound containing at least one active hydrogen group in the molecule. An active hydrogen group refers to an active group containing hydrogen that can react with an isocyanate group. As an active hydrogen group, a hydroxyl group, an amino group, a carboxyl group, a thiol group etc. are mentioned.
The active hydrogen group-containing compound (B) essentially comprises the following aromatic polyester polyol (B1), a tertiary amine compound (B2) having an active hydrogen group, and an active hydrogen group-containing compound (B3) having a carboxyl group. . In addition, other active hydrogen group-containing compounds other than the above may be included as long as the effects of the present invention are not inhibited.

The aromatic polyester polyol (B1) is a copolymer of a polycarboxylic acid or an anhydride thereof and a polyol, and at least one of the polycarboxylic acid or an anhydride thereof and a polyol is an aromatic compound. It is included. Further, the terminal of the aromatic polyester polyol (B1) is composed of a polyol, and has two or more active hydrogen groups in the molecule. The number of active hydrogen groups is preferably 2 to 4, more preferably 2 to 3, and still more preferably 2. As the aromatic polyester polyol (B1), only one type may be used, or two or more types may be used.
Thus, by using the aromatic polyester polyol (B1) and the other active hydrogen group-containing compound as essential components of the aromatic polyester-based urethane resin, the bundling property of the reinforcing fiber strand and the bundling property of the reinforcing fiber chopped strand are obtained. And the adhesiveness of a reinforcement fiber and matrix resin can be improved simultaneously. If an aliphatic polyester polyol having no aromatic compound in the molecule is used instead of the aromatic polyester polyol (B1), the strand convergence is low, the adhesion is hardly improved, and the heat resistance is also low. is there.

Examples of the polycarboxylic acid include aromatic dicarboxylic acids, sulfonic acid group-containing aromatic dicarboxylic acids, aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, and trifunctional or higher polycarboxylic acids.
Examples of the aromatic dicarboxylic acid include phthalic acid, terephthalic acid, isophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid, phthalic anhydride and the like.
Examples of the sulfonate-containing aromatic dicarboxylic acid include sulfoterephthalate, 5-sulfoisophthalate and the like.
As aliphatic dicarboxylic acid or alicyclic dicarboxylic acid, fumaric acid, maleic acid, itaconic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, dimer acid, 1,4-cyclohexanedicarboxylic acid, succinic anhydride, anhydride Maleic acid etc. are mentioned.
Examples of trifunctional or higher polycarboxylic acids include trimellitic acid, pyromellitic acid, trimellitic anhydride, and pyromellitic anhydride.

As said polyol, a diol, the trifunctional or more than trifunctional polyol, etc. are mentioned.
As the diol, ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, polybutylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, tetramethylene glycol 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, resorcine, hydroquinone, bisphenol A or its alkylene oxide adduct, and the like.
Examples of trifunctional or higher functional polyols include trimethylol ethane, trimethylol propane, glycerin, polyglycerin, pentaerythritol, ditrimethylol propane and the like.

  Among the above, a combination of an aromatic dicarboxylic acid and a diol is preferable as the aromatic polyester polyol (B1), and terephthalic acid, isophthalic acid, phthalic acid as the aromatic dicarboxylic acid, ethylene glycol, diethylene glycol, propylene glycol as the diol And neopentyl glycol are more preferred.

  The hydroxyl value of the aromatic polyester polyol (B1) is preferably 10 to 250 mg KOH / g, more preferably 15 to 150 mg KOH / g, and still more preferably 20 to 120 mg KOH / g. In addition, the hydroxyl value was measured based on JISK1557-1970.

  500-10000 are preferable, as for the number average molecular weight of aromatic polyester polyol (B1), 700-8000 are more preferable, and 1000-4000 are more preferable. In addition, the number average molecular weight as used in the field of this invention was computed by the gel permeation chromatograph (GPC) measuring method.

  The aromatic polyester polyol (B1) can be obtained by dehydration condensation of the above-described polycarboxylic acid or its anhydride and the above-described polyol, by the same method as the known polyester manufacturing method.

  The tertiary amine compound (B2) having an active hydrogen group refers to a tertiary amine compound having at least one active hydrogen group in the molecule. By using the tertiary amine compound (B2) having an active hydrogen group as an essential component, an ionic interaction with the carboxyl group introduced by the active hydrogen group-containing compound (B3) having a carboxyl group is expressed, The bundling performance of chopped strands can be imparted to the aromatic polyester urethane resin. The number of active hydrogen groups is preferably 1 to 4, and more preferably 1 to 3. Only one type of tertiary amine compound (B2) having an active hydrogen group may be used, or two or more types may be used.

The tertiary amine compound (B2) having an active hydrogen group is selected from a compound represented by the above general formula (1) and a compound represented by the above general formula (2), from the viewpoint of exhibiting the effects of the present invention. It is preferable that it is at least one type, and a compound represented by the above general formula (1) is more preferable.
In the general formula (1), R ¹ is a hydrocarbon group having 1 to 20 carbon atoms. R ¹ may be linear, branched or cyclic (alicyclic or araliphatic), but is preferably linear from the viewpoint that chopped strand bundling properties are easily obtained. As a hydrocarbon group, an alkyl group, an alkenyl group, an alkynyl group, an aryl group etc. are mentioned, An alkyl group is preferable. The number of carbon atoms in R ¹ is 1 to 12, more preferably 1 to 6, more preferably 1 to 4, 1 to 3 is most preferred.

In the general formula ^{(1), A} 1 O is an oxyalkylene group having 2 to 4 carbon atoms. Accordingly, (A ¹ O) _a is a polyoxyalkylene group (provided that a is 2 or more). Examples of A ¹ O include an oxyethylene group (EO), an oxypropylene group (PO), and an oxybutylene group (BO), but from the viewpoint of easy obtaining of chopped strand bundling properties, an oxyethylene group and an oxypropylene group are preferable. ^{A 1} O constituting the ^(A 1 _{O) a} may be a one, or may be two or more. In the case of two or more types, any of a block adduct, an alternate adduct, and a random adduct may be used. Ratio of ^(A 1 _O) in the whole _a EO is preferably at least 60 mol%, more preferably 70 to 100 mol%, more preferably 80 to 100 mol%, and most preferably 90 to 100 mol%.
In the general formula (1), a is a number of 1 to 20, from the viewpoint of suppressing the time-dependent moisture absorption of the urethane resin, 1 to 10 is preferable, 1 to 5 is more preferable, 1 to 3 is more preferable, 1 to 2 Is most preferred.

In the general formula (1), m is a number from 0 to 2, preferably 1 to 2 and more preferably 2 from the viewpoint of improving the water dispersibility of the urethane resin.
When there are a plurality of R ¹ and (A ¹ O) _{a in the} molecule, they may be identical to or different from each other.

In the general formula (2), R ² is a hydrocarbon group having 1 to 20 carbon atoms. The preferred range of R ² is the same as that of R ¹ .

In the general formula ^{(2), A} 2 is a hydrocarbon group having 1 to 10 carbon atoms. A ² may be linear or branched, but linear is preferable from the viewpoint that chopped strand convergence can be easily obtained. As a hydrocarbon group, an alkyl group, an alkenyl group, an alkynyl group etc. are mentioned, An alkyl group is preferable. The number of carbon atoms of A ² is preferably 1 to 6, more preferably 1 to 4, 1 to 3 is more preferable.

In the general formula (2), n is a number from 1 to 2, and is preferably 2 from the viewpoint of improving the water dispersibility of the urethane resin.
When there are a plurality of R ² and A ^{2 in the} molecule, they may be identical to or different from each other.

  As a tertiary amine compound having an active hydrogen group, triethanolamine, triisopropanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-butyldiethanolamine, N-t-butyldiethanol-amine, dihydroxyisopropylethylamine, dihydroxyisopropyl- n-Butylamine, dihydroxyisopropyl-t-butylamine, N, N-bis (2-hydroxypropyl) aniline, N, N-dimethylethanolamine, N, N-diethylethanolamine, N, N-dibutylethanolamine, N, N-dimethylisopropanolamine, N, N-diethylisopropanolamine, 2,4,6-tris (dimethylaminomethyl) phenol, EO adduct of decylamine (EO 2-20 ), PO adduct of decylamine (PO 2 to 20 mol), EO adduct of dodecylamine (E 2 to 20 mol), PO adduct of dodecylamine (PO 2 to 20 mol), EO adduct of octadecylamine (EO 2 to 2) 20 mol), PO adduct of octadecylamine (PO 2 to 20 mol), N, N-bis (2-aminoethyl) methylamine, N, N-bis (3-aminopropyl) methylamine, N, N-bis Examples include (aminopropyl) ethylamine, N, N-dimethyl-1,3-diaminopropane, N, N-diethyl-1,3-diaminopropane, N, N-diethylethylenediamine, N, N-dimethylethylenediamine and the like.

  Among these, triethanolamine, triisopropanolamine, N-methyldiethanolamine and N-ethyldiethanolamine are preferred from the viewpoint that good chopped strand focusing property can be easily obtained by combined use with the active hydrogen group-containing compound (B3) having a carboxyl group. N, N-dimethylethanolamine, N, N-diethylisopropanoylamine, N, N-diethylethanolamine, N, N-diethylethylenediamine and N, N-dimethylethylenediamine are preferred.

  The active hydrogen group-containing compound (B3) having a carboxyl group refers to a compound having at least one carboxyl group and at least one active hydrogen group in the molecule. By using the active hydrogen group-containing compound (B3) having a carboxyl group as an essential component, it is possible to impart water dispersibility to the aromatic polyester urethane resin. Furthermore, the ionic interaction with the tertiary amine structure introduced by the tertiary amine compound (B2) having an active hydrogen group is developed, and the bundling performance of the reinforced fiber chopped strand can be imparted to the aromatic polyester urethane resin. 1-4 are preferable and, as for the number of active hydrogen groups, 2-3 are more preferable. The active hydrogen group-containing compound (B3) having a carboxyl group may be used singly or in combination of two or more.

Examples of the active hydrogen group-containing compound (B3) having a carboxyl group include polyols having a carboxyl group, monools having a carboxyl group, and the like.
As the polyol having a carboxyl group, 2,2-dimethylol propionic acid, 2,2-dimethylol butanoic acid, 2,2-dimethylol pentanoic acid, 2,2-dimethylol heptanoic acid, dioxymaleic acid, 2 , 6-dioxybenzoic acid and the like.
Examples of monools having a carboxyl group include glycolic acid, lactic acid, hydroxybutyric acid, salicylic acid, parahydroxybenzoic acid, coumaric acid and the like.
Among these, from the viewpoint of the excellent water dispersibility of the aromatic polyester urethane resin, as the active hydrogen group-containing compound (B3) having a carboxyl group, a polyol having a carboxyl group is preferable, and 2,2-dimethylol propionone The acid, 2,2-dimethylol butanoic acid is more preferred, and 2,2-dimethylol propionic acid is more preferred.

The active hydrogen group-containing compound (B) preferably further contains a trifunctional or higher functional hydrogen group-containing compound (B4). By using the trifunctional or higher functional hydrogen group-containing compound (B4), the sizing agent has more excellent chopped strand bundling properties. The trifunctional or higher active hydrogen group-containing compound (B4) refers to a compound containing at least three active hydrogen groups in the molecule. In addition, the trifunctional or higher active hydrogen group-containing compound (B4) includes the above-mentioned aromatic polyester polyol (B1), a tertiary amine compound (B2) having an active hydrogen group, and an active hydrogen group-containing compound (B3) having a carboxyl group. The compound except for). 3-8 are preferable and, as for the number of active hydrogen groups, 3-4 are more preferable. Examples of the trifunctional or more active hydrogen group-containing compound (B4) include polyols having a trifunctional or more active hydrogen group, and polyamines having three or more functions.
Examples of trifunctional or higher functional polyols include trimethylol ethane, trimethylol propane, glycerin, polyglycerin, sorbitol, pentaerythritol, and ditrimethylol propane. Examples of the trifunctional or higher polyamines include melamine, diethylenetriamine, triethylenetetramine, tri (aminomethyl) propane and the like. Among these, trimethylolpropane, pentaerythritol and ditrimethylolpropane are preferable, and trimethylolpropane and pentaerythritol are more preferable, from the viewpoint of excellent water dispersibility.

The active hydrogen group-containing compound (B) preferably further contains a polyalkylene glycol (B5) having a number average molecular weight of 100 to 2,000. By using the polyalkylene glycol (B5), the sizing agent has excellent uniform adhesion. In addition, the number average molecular weight as used in the field of this invention says the value which was measured on the following measurement conditions by the gel permeation chromatograph (GPC) measuring method, and was converted into polystyrene.
(GPC measurement conditions)
Device: Device name "HPLC LC-6A SYSTEM" (manufactured by SHIMAZU)
Columns: “KF-800P (10 mm × 4.6 mm φ)”, “KF-804 (300 mm × 8 mm φ)”, “KF-802.5 (300 mm × 8 mm φ)”, “KF-801 (300 mm × 8 mm φ)” Above, made by SHODEX
Mobile phase: tetrahydrofuran (THF)
Flow rate: 1.0 ml / min
Sample volume: 100 μl (100-fold dilution)
Column temperature: 50 ° C
Standard curve preparation standard substance: polystyrene (PSt)

  100-2000 are preferable, as for the number average molecular weight of polyalkylene glycol (B5), 150-1500 are more preferable, and 200-1000 are more preferable. If the molecular weight is less than 100, the water dispersibility may be insufficient. On the other hand, if the molecular weight is more than 2000, the adhesiveness may be reduced.

Examples of polyalkylene glycols include polyethylene glycol, polypropylene glycol, polybutylene glycol, polytetramethylene glycol, polyethylene glycol / polypropylene glycol block copolymer, polyethylene glycol / polypropylene glycol random copolymer and the like. Alternatively, those which are blocked with an alkyl group, an aromatic group or the like and one end of which is a hydroxyl group can be used.
Among these, polyethylene glycol, polypropylene glycol, polybutylene glycol and polytetramethylene glycol are preferable, and polyethylene glycol, polypropylene glycol and polytetramethylene glycol are more preferable.

The active hydrogen group-containing compound (B) may contain other active hydrogen group-containing compounds as long as the effects of the present invention are not impaired. Examples of the other active hydrogen group-containing compound (B6) include diols and diamines.
As a diol, ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, tetramethylene glycol, 1,4-cyclohexanediol, 1, 4-cyclohexanedimethanol, resorcinol, hydroquinone, bisphenol A and the like. Examples of the diamine include aliphatic diamines such as ethylene diamine, propylene diamine, hexamethylene diamine and 2,2,4-trimethyl hexamethylene diamine, and alicyclic diamines such as isophorone diamine and 1,4-diaminocyclohexane.

Further, the above-mentioned aromatic polyester-based urethane resin is composed of a constituent unit (a) derived from the organic polyisocyanate compound (A) and a constituent unit (b) derived from the active hydrogen group-containing compound (B) It can be expressed as an aromatic polyester-based urethane resin. The structural unit (b) is a structural unit (b1) derived from an aromatic polyester polyol (B1), a structural unit (b2) derived from a tertiary amine compound (B2) having an active hydrogen group, and an active hydrogen having a carboxyl group The structural unit (b3) derived from the group-containing compound (B3) is essentially contained. The structural unit (b) is a structural unit (b4) derived from the above-mentioned trifunctional or higher active hydrogen group-containing compound (B4), a structural unit (b5) derived from the above polyalkylene glycol (B5), the other The constituent unit (b6) derived from the active hydrogen group-containing compound (B6) may be included.
Here, the structural unit (a) derived from the organic polyisocyanate compound (A) refers to a unit constituted using the organic polyisocyanate compound (A) as a raw material, and one of the urethane bonds “—NHC (ウ レ タ ン O) — Including the structure of On the other hand, the structural unit (b) derived from the active hydrogen group-containing compound (B) means a unit constituted from the active hydrogen group-containing compound (B) as a raw material, and from the active hydrogen group-containing compound (B) Say the rest except for.

The ratio of the structural unit derived from the tertiary amine compound (B2) having an active hydrogen group is 0.1, when the structural unit derived from the aromatic polyester polyol (B1) in the aromatic polyester urethane resin is 100 moles. 1000 mol is preferable, 0.2 to 800 mol is more preferable, and 0.5 to 500 mol is more preferable. When the ratio is less than 0.1 mol, the bundling ability of the reinforcing fiber strand may be insufficient. On the other hand, when the ratio is more than 1000 mol, the heat resistance may be insufficient.
Similarly, the ratio of the constituent unit derived from the active hydrogen group-containing compound (B3) having a carboxyl group is preferably 0.1 to 1000 mol, more preferably 0.5 to 800 mol, and still more preferably 1 to 500 mol. If the ratio is less than 0.1 mol, the water dispersibility may be insufficient. On the other hand, when the ratio is more than 1000 moles, the stability with time of the sizing agent may be insufficient due to the hygroscopicity of the urethane resin.

  When the constituent unit derived from the tertiary amine compound (B2) having an active hydrogen group in the aromatic polyester urethane resin is 100 moles, the composition derived from the active hydrogen group-containing compound (B3) having a carboxyl group The ratio of the unit is preferably 0.5 to 20000 mol, more preferably 1 to 15000 mol, and still more preferably 2 to 12000 mol. When the ratio is less than 0.5 mol and when the ratio is more than 20000 mol, an active hydrogen group-containing compound having a tertiary amine structure and a carboxyl group introduced by a tertiary amine compound (B2) having an active hydrogen group Since the ionic interaction by the carboxyl group introduced by (B3) is insufficient, the bundling property of the reinforcing fiber chopped strand may be insufficient.

  When the active hydrogen group-containing compound (B) further includes an active hydrogen group-containing compound (B4) having three or more functions, 100 mol of structural units derived from the aromatic polyester polyol (B1) in the aromatic polyester urethane resin As for the ratio of the structural unit derived from the trifunctional or more active hydrogen group containing compound (B4), 1-800 mol is preferable and 2-700 mol is more preferable. When the ratio is more than 1000 mol, both the heat resistance and the water dispersion stability may be insufficient.

  When the active hydrogen group-containing compound (B) further contains a polyalkylene glycol (B5), the polyalkylene glycol, when the structural unit derived from the aromatic polyester polyol (B1) in the aromatic polyester urethane resin is 100 moles, The ratio of the structural unit derived from (B5) is preferably 0 to 1000 mol, more preferably 1 to 700 mol, and still more preferably 2 to 500 mol. When the ratio is more than 1000 mol, both adhesion and heat resistance may be insufficient.

Next, a preferable ratio of each structural unit when the entire structural unit (b) derived from the active hydrogen group-containing compound (B) is 100 mol% will be described.
5-80 mol% is preferable, as for the ratio of the structural unit (b1) to the whole structural unit (b), 10-70 mol% is more preferable, and 15-60 mol% is further more preferable. If the proportion is less than 5 mol%, the adhesion and heat resistance may be insufficient. On the other hand, when the ratio is more than 80 mol%, it may be difficult to solubilize.
0.05-60 mol% is preferable, as for the ratio of the structural unit (b2) to the whole structural unit (b), 0.1-50 mol% is more preferable, and 0.15-40 mol% is more preferable. If the ratio is less than 0.05 mol%, chopped strand convergence may be insufficient. On the other hand, when the ratio is more than 60 mol%, the heat resistance may be insufficient.
0.05-65 mol% is preferable, as for the ratio of the structural unit (b3) to the whole structural unit (b), 0.1-60 mol% is more preferable, and 0.2-55 mol% is more preferable. If the ratio is less than 0.05 mol%, chopped strand convergence may be insufficient. On the other hand, if the ratio is more than 65 mol%, the hygroscopicity may be high or the heat resistance may be insufficient.
Moreover, 35 mol% or more is preferable, and, as for the ratio of the sum total of structural unit (b1), structural unit (b2), and structural unit (b3) which occupies the whole structural unit (b), 45 mol% or more is more preferable, and 50 mol % Or more is more preferable. When the ratio is less than 35 mol%, both good chopped strand convergence and adhesion may not be obtained.

When the active hydrogen group-containing compound (B) contains a trifunctional or higher functional hydrogen group-containing compound (B4), the proportion of the structural unit (b4) in the entire structural unit (b) is preferably 1 to 70 mol%, 3 to 60 mol% is more preferable, and 5 to 50 mol% is more preferable. If the proportion is less than 1 mol%, adhesion may be insufficient. On the other hand, when the ratio is more than 70 mol%, reaction control may be difficult and synthesis may be impossible.
The proportion of the total of the structural unit (b1), the structural unit (b2), the structural unit (b3) and the structural unit (b4) in the structural unit (b) at that time is preferably 40 mol% or more, and 50 mol% The above is more preferable, and 60 mol% or more is more preferable.

When the active hydrogen group-containing compound (B) contains a polyalkylene glycol (B5), the proportion of the structural unit (b5) in the entire structural unit (b) is preferably 1 to 40 mol%, and 3 to 35 mol%. Is more preferable, and 5 to 30 mol% is more preferable. If the proportion is more than 40 mol%, adhesion and heat resistance may be insufficient.
The ratio of the sum of the structural unit (b1), the structural unit (b2), the structural unit (b3) and the structural unit (b5) in the structural unit (b) at that time is preferably 40 mol% or more, and 50 mol% The above is more preferable, and 60 mol% or more is more preferable.

  When the active hydrogen group-containing compound (B) further contains another active hydrogen group-containing compound (B6), the proportion of the structural unit (b6) in the entire structural unit (b) is preferably 1 to 40 mol%, 2 to 35 mol% is more preferable, and 5 to 30 mol% is more preferable. If the proportion is more than 40% by mole, good adhesion may not be obtained.

  40/60-60/40 are preferable, as for the molar ratio of a structural unit (a) and a structural unit (b), 45/55-55/45 are more preferable, and 47/53-50/50 are more preferable.

In addition, when it is made to emulsify and disperse | distribute aromatic polyester-type urethane resin in water, and it disperses and uses it from the point which can make unnecessary addition of emulsifier components, such as surfactant, derived from the active hydrogen group containing compound (B3) which has a carboxyl group It is preferable to neutralize the carboxyl group introduce | transduced by (3) part or all by a basic component.
As the basic component, inorganic bases such as sodium hydroxide and potassium hydroxide, monopropylamine, monobutylamine, diethylamine, triethylamine, tributylamine, monoethanolamine, monocyclohexylamine, diethanolamine, triethanolamine, dimethylethanolamine And amines such as diethylenetriamine, and ammonia. Among these, triethylamine, monoethanolamine, diethanolamine, triethanolamine, dimethylethanolamine, diethylenetriamine and ammonia are more preferable.

  From the viewpoint of resin physical properties and heat resistance, the number average molecular weight of the aromatic polyester-based urethane resin used in the present invention is preferably 5,000 to 200,000, more preferably 7,000 to 150,000, and still more preferably 8,000 to 130,000. If the molecular weight is less than 5,000, the heat resistance may be insufficient, and the resin physical properties necessary for the sizing agent may not be obtained. On the other hand, when the molecular weight is more than 200,000, the stability as a sizing agent may be reduced, and uniform application to reinforcing fibers may be difficult.

120 degrees C or less is preferable, as for the glass transition point when the aromatic polyester type urethane resin used by this invention is measured by a differential scanning calorimeter (DSC), -25-100 degreeC is more preferable, and -15-90 degreeC is further more preferable preferable. When the glass transition point is 120 ° C. or less, the water dispersibility of the polyurethane resin is improved, and the handleability and stability as a sizing agent are improved.
In the present invention, the glass transition point refers to the straight line extending from each baseline and is equidistant along the vertical axis in the portion showing the step-like change of the DSC curve obtained by DSC measurement according to JIS-K7121. It is defined as a point (unit: ° C.) at which a certain straight line and the curve of the step change intersect.

  There is no limitation in particular as a manufacturing method of aromatic polyester type urethane resin, A well-known method is employable. For example, a one-shot method in which all the components are reacted simultaneously, or a multistage method in which an active hydrogen group-containing compound (B) is added stepwise to an organic polyisocyanate compound (A) and reacted, or an organic polyisocyanate compound (A) The compound may be reacted with an active hydrogen group-containing compound (B) to synthesize a prepolymer having an isocyanate at the end, followed by reaction with a chain extender, such as a prepolymer method.

  When preparing the aromatic polyester-based urethane resin of the present invention, a urethanization catalyst can be used if necessary. As a urethanization catalyst which can be used in the present invention, for example, nitrogen-containing compounds such as triethylamine, triethylenediamine or N-methylmorpholine, metal salts such as potassium acetate, zinc stearate or tin octylate, dibutyl laurate and the like Organic metal compounds and the like.

[Sizing agent for reinforcing fibers]
The sizing agent of the present invention is for reinforcing fibers used to reinforce a matrix resin. The matrix resin is preferably a thermoplastic resin from the viewpoint that the adhesion improving effect of the sizing agent of the present invention is higher. As a reinforcing fiber, carbon fiber is particularly preferable.
The sizing agent of the present invention essentially contains the above-mentioned aromatic polyester-based urethane resin. 10 weight% or more is preferable, 20 weight% or more is more preferable, 30 weight% or more is further more preferable, and 50 weight% or more of the weight ratio of the aromatic polyester-type urethane resin to the non volatile matter of a sizing agent is especially preferable. When the proportion by weight is less than 10% by weight, the excellent adhesion, the excellent strand bundling ability and the excellent chopped strand bundling characteristic of the present compound can not be obtained. The non-volatile component in the present invention refers to a bone-drying component when the sizing agent is heat-treated at 105 ° C. to remove the solvent and the like, and reaches a constant weight.
When the polyoxyalkylene alkyl ether (C) described later and the other resin component (E) are contained, the weight ratio of the aromatic polyester-based urethane resin in the non-volatile portion of the sizing agent is preferably 10 to 99.5% by weight. -98 weight% is more preferable, 30-95 weight% is further more preferable, 50-90 weight% is especially preferable.

The sizing agent of the present invention has a dynamic surface tension of 1 bubble per 100 ms by the maximum bubble pressure method (bubble pressure method) when water is added to make the nonvolatile matter concentration of the sizing agent 1% by weight. It is preferable to be in the range of 40 to 70 mN / m when measured under generated conditions.
Due to this property, in the sizing agent application step to the fiber, the sizing agent rapidly adheres uniformly to the inside of the fiber strand, specifically, between the fiber and the fiber and on the fiber. When the composite is formed, the sizing agent layer uniformly deposited on the fibers improves the wettability of the matrix resin to the fibers, and as a result, the physical properties of the composite material are improved.

  If the dynamic surface tension is more than 70 mN / m, the uniform adhesion of the sizing agent to reinforcing fibers may be reduced. On the other hand, when the dynamic surface tension is less than 40 mN / m, it may be difficult to control the amount of the sizing agent attached to the reinforcing fibers. The dynamic surface tension is preferably 40 to 70 mN / m, more preferably 45 to 65 mN / m, and particularly preferably 45 to 60 mN / m.

  Moreover, 20 to 100 weight% is preferable, as for the weight ratio of the aromatic polyester-type urethane resin to the non volatile matter of the sizing agent in that case, 30 to 95 weight% is more preferable, and 40 to 90 weight% is more preferable.

  The sizing agent of the present invention preferably further contains a polyoxyalkylene alkyl ether (C) which is an alkylene oxide adduct of a C4 to C20 monohydric alcohol. By containing the polyoxyalkylene alkyl ether (C) in addition to the aromatic polyester-based urethane resin, the sizing agent rapidly adheres uniformly between fibers and fibers and on the fibers, and has excellent uniform adhesion. Therefore, even better adhesion can be given to the reinforcing fiber. The polyoxyalkylene alkyl ether (C) may be used alone or in combination of two or more. The method for producing the polyoxyalkylene alkyl ether (C) is not particularly limited, and any known method can be adopted.

  The monohydric alcohol having 4 to 20 carbon atoms may be linear, branched or cyclic (alicyclic or aromatic aliphatic) and may be saturated or unsaturated, primary alcohol, secondary alcohol, tertiary alcohol It may be either. Examples of linear saturated alcohols include butyl alcohol, hexyl alcohol, octyl alcohol, decyl alcohol, dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol, hexadecyl alcohol, octadecyl alcohol and the like. Examples of branched saturated alcohols include 2-ethylhexyl alcohol, isooctyl alcohol, isotridecyl alcohol, isohexadecyl alcohol, isooctadecyl alcohol and the like. Examples of cyclic alcohols include cyclohexyl alcohol and benzyl alcohol. Among them, from the viewpoint of uniform adhesion, linear or branched saturated alcohols having 6 to 18 carbon atoms are preferable, and hexyl alcohol, 2-ethylhexyl alcohol, dodecyl alcohol, tridecyl alcohol and tetradecyl alcohol are more preferable.

As said alkylene oxide, a C2-C4 alkylene oxide is preferable. Specifically, ethylene oxide (hereinafter sometimes referred to as EO), propylene oxide (hereinafter sometimes referred to as PO), 1,2-, 1,3-, 2,3- or 1,4-butylene oxide (hereinafter referred to as And the like. Two or more alkylene oxides may be used. Among these, EO and / or PO are preferable from the viewpoint of uniform adhesion. Although the addition method of the alkylene oxide in the case of using 2 or more types includes random addition, block addition, these combined use, etc., block addition and block addition after random addition are preferable.
From the viewpoint of uniform adhesion, the addition mole number of the alkylene oxide is preferably 1 to 12 moles, more preferably 2 to 10 moles, and still more preferably 3 to 8 moles.

  200-2000 are preferable, as for the number average molecular weight of C component, 250-1800 are more preferable, and 280-1500 are more preferable.

  When the sizing agent of the present invention contains a polyoxyalkylene alkyl ether (C), the weight ratio of the polyoxyalkylene alkyl ether (C) in the non-volatile portion of the sizing agent is preferably 0.5 to 40% by weight, 1 -35 weight% is more preferable, and 2-30 weight% is further more preferable. If the proportion by weight of the polyoxyalkylene alkyl ether (C) is more than 40% by weight, the sizing agent may be separated on the reinforcing fiber and the adhesion may be reduced.

  The sizing agent of the present invention may further contain other resin component (E) other than the above-mentioned aromatic polyester-based urethane resin. The other resin component (E) is not particularly limited as long as it is a thermoplastic resin or thermosetting resin, but, for example, epoxy resin, unsaturated polyester resin, saturated polyester resin, vinyl ester resin, polyamide resin, polyolefin resin, polyurethane Resin and phenol resin etc. are mentioned. Other resin components (E) may be used in combination of two or more. These resin components are appropriately selected in consideration of the affinity to the matrix resin.

  As an epoxy resin, for example, bisphenol type epoxy resin, amine type epoxy resin, phenol novolak type epoxy resin, cresol novolac type epoxy resin, resorcinol type epoxy resin, phenol aralkyl type epoxy resin, naphthol aralkyl type epoxy resin, dicyclopentadiene type An epoxy resin, an epoxy resin having a biphenyl skeleton, an isocyanate-modified epoxy resin, a tetraphenylethane type epoxy resin, a triphenylmethane type epoxy resin and the like can be mentioned. Here, a bisphenol type epoxy resin is obtained by glycidylating two phenolic hydroxyl groups of a bisphenol compound, and bisphenol A type, bisphenol F type, bisphenol AD type, bisphenol S type, or halogen or alkyl of these bisphenols A substituted body, a hydrogenated product, etc. can be mentioned. Moreover, not only a monomer but a high molecular weight product having a plurality of repeating units can be suitably used.

  As unsaturated polyester resin and saturated polyester resin, the polyester resin obtained by making the acid component containing polyhydric carboxylic acid and polyhydric alcohol react can be mentioned. Examples of polyvalent carboxylic acids include maleic acid, fumaric acid, itaconic acid, phthalic acid, trimellitic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, adipic acid, sebacic acid, sodium 5-sulfoisophthalic acid and the like, and the like. Derivatives of the acid anhydride of the above, etc. may be mentioned, and two or more of these may be used in combination. Examples of polyhydric alcohols include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, neopentyl Aliphatic glycols such as glycol, cycloaliphatic diols such as cyclopentanediol and cyclohexanediol, hydrogenated bisphenol A, bisphenol A ethylene oxide (1 to 100 moles) adduct, bisphenol A propylene oxide (1 to 100 moles) adduct, Aromatic diols such as xylene glycol, and polyhydric alcohols such as trimethylolpropane, pentaerythritol, and glycerol may be mentioned, and two or more of these may be used in combination. Specific examples of the unsaturated polyester resin include, for example, a condensate of fumaric acid or maleic acid and an ethylene oxide adduct of bisphenol A, a condensate of fumaric acid or maleic acid and a propylene oxide adduct of bisphenol A, fumaric acid Or a condensate of maleic acid and an ethylene oxide and propylene oxide adduct of bisphenol A (the addition of ethylene oxide and propylene oxide may be random or block). Specific examples of the saturated polyester include, for example, a condensation product of isophthalic acid and diethylene glycol, a condensation product of isophthalic acid and Na 5-sulfoisophthalic acid and diethylene glycol, isophthalic acid and terephthalic acid and 5-sulfoisophthalic acid Na and ethylene glycol And condensation products of diethylene glycol and the like. In addition, transesterification reaction may be performed using methyl ester of polyvalent carboxylic acid or the like to obtain a target polyester resin.

  As a vinyl ester resin, the epoxy (meth) acrylate etc. which are obtained by esterifying the said epoxy resin and (alpha), (beta)-unsaturated monocarboxylic acid can be mentioned, for example. 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, bisphenol type epoxy resin (meth) acrylate modified product (terminal (meth) acrylate obtained by reacting epoxy group of bisphenol A type epoxy resin and carboxyl group of (meth) acrylic acid Modified resin etc. can be mentioned.

  The polyamide resin is not particularly limited as long as it is a resin that forms a main chain by repeating an amide bond, and polyamide 6 (by ring-opening polymerization of ε-caprolactam), polyamide 66 (by condensation polymerization of hexamethylenediamine and adipic acid) And polyamide resins etc. which are made water-soluble by introducing a hydrophilic group into the main chain.

  Examples of the polyolefin resin include polyethylene, polypropylene, copolymers selected from several kinds of monomers such as ethylene, propylene, butene, and vinyl acetate, and acid-modified products thereof.

  As a polyurethane resin, active hydrogen essentially containing an organic polyisocyanate compound, an aromatic polyester polyol (B1), a tertiary amine compound (B2) having an active hydrogen group, and an active hydrogen group-containing compound (B3) having a carboxyl group There is no particular limitation as long as it is other than an aromatic polyester-based urethane resin which is a reaction product of a group-containing compound.

  As a phenol resin, the condensation reaction product of phenols (phenol, cresol, xylenol etc.) and aldehydes (formaldehyde etc.) can be mentioned.

  When the sizing agent of the present invention contains other resin component (E), the weight ratio of the other resin component (E) to the non-volatile content of the sizing agent is preferably 5 to 89.5% by weight, and 10 to 85% by weight Is more preferable, and 15 to 80% by weight is further preferable. If it exceeds 89.5% by weight, the excellent adhesion, the excellent strand convergence and the excellent chopped strand convergence which are the features of the present invention may not be obtained.

  In the sizing agent of the present invention, the weight loss rate at 300 ° C. when the non-volatile content of the sizing agent is measured by a differential thermal differential balance (TG-DTA) is preferably 15% by weight or less, and further 10% by weight or less preferable. When the weight reduction rate at 300 ° C. exceeds 20% by weight, the sizing agent may be thermally decomposed on the reinforcing fibers, which may cause adhesion inhibition between the matrix resin and the reinforcing fibers.

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

In the sizing agent of the present invention, the aromatic polyester-based urethane resin is formed by self emulsification and / or emulsification dispersion in water. The average particle size of the aromatic polyester-based urethane resin is not particularly limited, but is preferably 10 μm or less, more preferably 0.01 to 1 μm, and still more preferably 0.01 to 0.5 μm. When the average particle size is more than 10 μm, not only adhesion to reinforcing fibers can not be achieved uniformly, but also the sizing agent itself may be separated in several days, and storage stability may be poor and it may not be practical.
In addition, the average particle diameter as used in the field of this invention means the average value computed from the particle size distribution measured by laser diffraction / scattering type particle size distribution measuring apparatus (LA-910 made from Horiba).

  The sizing agent of the present invention may contain other components other than the aromatic polyester-based urethane resin described above, as long as the effects of the present invention are not impaired. Examples of other components include various surfactants, various smoothing agents, antioxidants, flame retardants, antibacterial agents, crystal nucleating agents, antifoaming agents and the like, and one or more of them may be used in combination You may use.

When the surfactant contains a resin which is insoluble or hardly soluble in water, in an aromatic polyester urethane resin or other sizing agent, it can be used as an emulsifying agent to efficiently carry out aqueous emulsification.
The surfactant is not particularly limited, and known ones can be appropriately selected and used from nonionic surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants. The surfactant may be used alone or in combination of two or more.

Examples of nonionic surfactants include alkylene oxide-added nonionic surfactants (higher alcohols, higher fatty acids, alkylphenols, styrenated phenols, benzylphenol, sorbitan, sorbitan esters, castor oil, hydrogenated castor oil, etc. And alkylene oxides such as propylene oxide (two or more of which can be used in combination) added, those obtained by adding a higher fatty acid to polyalkylene glycol, ethylene oxide / propylene oxide copolymer, etc. .
As an anionic surfactant, for example, alkyl carboxylic acid (salt), polyoxyethylene alkyl ether carboxylic acid (salt), alkyl sulfuric acid ester (salt), sulfuric acid ester of polyoxyalkylene alkyl ether (salt), alkyl sulfonic acid Examples include (salts), sulfonic acids (salts) of polyoxyalkylene alkyl ethers, alkyl phosphoric acid esters (salts), and phosphoric acid esters (salts) of polyoxyalkylene alkyl ethers.

As a cationic surfactant, for example, quaternary ammonium salt type cationic surfactant (lauryl trimethyl ammonium chloride, oleyl methyl ethyl ammonium ethosulfate etc.), amine salt type cationic surfactant (polyoxyethylene lauryl amine) Lactate etc. can be mentioned.
Examples of amphoteric surfactants include amino acid type amphoteric surfactants (sodium lauryl aminopropionate etc.), betaine type amphoteric surfactants (stearyl dimethyl betaine, lauryl dihydroxyethyl betaine etc) and the like.

  The sizing agent of the present invention can exhibit excellent stranding and uniform adhesion while limiting the use of surfactant. If a large amount of surfactant is contained, the heat resistance of the sizing agent is lowered, which is not preferable. From such a viewpoint, the ratio of the surfactant to the non-volatile component of the sizing agent is preferably 30% by weight or less, more preferably 20% by weight or less, still more preferably 10% by weight or less, and particularly preferably 5% by weight or less.

The concentration of the non-volatile component 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 which is easily handled as a product, and the like. In consideration of the transportation cost of the product and the like, the weight ratio of the non-volatile component in the entire sizing agent is preferably 10 to 100% by weight, more preferably 15 to 100% by weight, and particularly preferably 20 to 100% by weight.
Further, the weight ratio of the total 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 compounds which do not remain as a non-volatile component during heat treatment, safety to humans during handling and contamination prevention of natural environment It is not preferable from the viewpoint.

  In addition to the above-mentioned aqueous dispersions and aqueous solutions, in addition to the above-mentioned human safety and environmental pollution prevention viewpoints, solvents other than water, such as organic solvents and the like, from the viewpoint of preventing time-lapse thickening and solidification of aqueous dispersions and aqueous solutions. Even if it is not contained or contained, it is preferably 10% by weight or less, more preferably 8% by weight or less, and still more preferably 5% by weight or less, based on the whole sizing agent.

  There is no limitation in particular about the method to manufacture the sizing agent of this invention as a water dispersion, A well-known method is employable. As described above, the method of forming an aqueous dispersion in the production of an aromatic polyester urethane resin, the method of emulsifying and dispersing each component constituting the sizing agent into warm water under stirring, and the method of forming the sizing agent The method of mixing the emulsion dispersion liquid which carried out emulsification dispersion of the component beforehand, after mixing each component which comprises a sizing agent, heating the obtained mixture above a softening point, mechanical shear using a homogenizer, a homomixer, a ball mill etc. There is a method of gradually injecting water and applying phase inversion emulsification while applying force.

[Reinforcing fiber strand, reinforcing fiber chopped strand and manufacturing method thereof]
The reinforcing fiber strand of the present invention is obtained by attaching the above-mentioned sizing agent for reinforcing fiber to a raw material reinforcing fiber strand, and is a reinforcing fiber for reinforcing a matrix resin. The reinforcing fiber strand of the present invention is excellent in adhesion to the matrix resin. Furthermore, since the reinforcing fiber sizing agent having excellent bundling properties is treated, the handling of the strands is improved, and stable strand feeding during operation can be maintained. The stable strand feeding property can suppress the deterioration of the fiber reinforced composite material due to the shortage of the feeding amount. The matrix resin is preferably a thermoplastic resin from the viewpoint that the adhesion improving effect of the sizing agent of the present invention is high.

  The reinforcing fiber chopped strand of the present invention is obtained by cutting the reinforcing fiber strand to which the sizing agent for reinforcing fiber is adhered to the raw material reinforcing fiber strand, and is a reinforcing fiber for reinforcing the matrix resin. As a cutting method of a reinforced fiber strand, cutters normally used, such as a rotary type cutter and a guillotine cutter, can be used suitably. The length of the reinforcing fiber chopped strand is preferably 3 to 25 mm, more preferably 5 to 20 mm, and still more preferably 6 to 15 mm. If the length is less than 3 mm, the bulk density of the chopped strands may be reduced, and the handling properties may be reduced. On the other hand, if the length is more than 25 mm, the supply stability to the injection molding machine or the extruder may be unstable, and it may be difficult to obtain a stable fiber-reinforced composite material.

  The reinforced fiber chopped strand of the present invention is excellent in adhesion to a matrix resin. Furthermore, in order to have excellent focusing, it is possible to suppress the occurrence of free fibers and clogging when feeding chopped strands to a molding machine, and to obtain a fiber reinforced composite material in which a matrix resin and reinforcing fibers are uniformly mixed. it can. The matrix resin is preferably a thermoplastic resin from the viewpoint that the adhesion improving effect of the sizing agent of the present invention is higher.

The amount of attachment of the sizing agent to the raw material reinforcing fiber strand can be appropriately selected, and may be a necessary amount for the reinforcing fiber strand to have a desired function, but the amount of adhesion is 0 to the raw material reinforcing fiber strand. It is preferable that it is .1 to 20 weight%. In the reinforcing fiber strand in the long fiber form, the adhesion amount is more preferably 0.1 to 10% by weight, further preferably 0.5 to 5% by weight with respect to the raw material reinforcing fiber strand. Moreover, in a reinforced fiber chopped strand, it is more preferable that it is 0.5 to 20 weight%, and 1 to 10 weight% is more preferable.
When the adhesion amount of the sizing agent is small, it is difficult to obtain the effects of the present invention on heat resistance, resin impregnation property and adhesion property, and the bundling property of the reinforcing fiber strand may be insufficient and the handleability may be deteriorated. If the amount of the sizing agent deposited is too large, the reinforcing fiber strands become too rigid, which may deteriorate the handleability or the resin impregnation during composite molding, which is not preferable.

The method for producing a reinforcing fiber strand includes the above-mentioned sizing agent, and the weight ratio of non-volatile components is 0.5 to 10% by weight, and the total weight ratio of water and non-volatile components is 90% by weight or more. The process comprises a preparation step to be prepared, and an adhesion step of adhering the treatment liquid to the raw material reinforcing fiber strand so that the adhesion amount of non volatile matter is 0.1 to 20% by weight with respect to the raw material reinforcing fiber strand.
In the preparation process, the weight ratio of the non-volatile component to the treatment liquid is more preferably 0.5 to 10% by weight, and still more preferably 1 to 5% by weight. The total weight ratio of water and non-volatile components is more preferably 95% by weight or more, still more preferably 99% by weight or more, and particularly preferably 100% by weight.
About the adhesion amount of preferable non volatile matter in an adhesion process, it is as a front paragraph. The method for attaching the sizing agent to the raw material reinforcing fiber strand is not particularly limited, but it is a method for attaching the sizing agent to the raw material reinforcing fiber strand by a kiss roller method, roller immersion 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 adhesion thing, For example, it can heat-dry with a heating roller, a hot air, a hot plate, etc.

  In addition, when attaching the sizing agent of the present invention to the raw material reinforcing fiber strand, all the components of the sizing agent may be attached after mixing, or the components may be attached separately in two or more stages. . In addition, thermosetting resin such as epoxy resin, unsaturated polyester resin, vinyl ester resin, phenol resin and / or polyolefin resin other than the polymer component of the present invention, polyester resin, nylon resin within a range not to inhibit the effect of the present invention A thermoplastic resin such as an acrylic resin may be attached to the raw material reinforcing fiber strand.

  As a reinforcing fiber strand to which the sizing agent of the present invention can be applied (raw material), various inorganic fibers such as carbon fiber, glass fiber, ceramic fiber, aramid fiber, polyethylene fiber, polyethylene terephthalate fiber, polybutylene terephthalate fiber, polyethylene naphthalate Strands of various organic fibers such as fiber, polyarylate fiber, polyacetal fiber, PBO fiber, polyphenylene sulfide fiber, polyketone fiber and the like can be mentioned. From the viewpoint of physical properties as a fiber-reinforced composite material to be obtained, as a (raw material) reinforcing fiber strand, 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 preferred, and carbon fiber strands are more preferred.

[Fiber-reinforced composite material]
The fiber reinforced composite material of the present invention comprises a matrix resin and the above-mentioned reinforcing fiber strands. The reinforcing fiber strand is treated with the sizing agent of the present invention, the sizing agent is uniformly attached, the affinity with the reinforcing fiber strand and the matrix resin becomes good, and a fiber-reinforced composite material excellent in adhesiveness is obtained. Furthermore, the thermal decomposition of the sizing agent during high temperature treatment can be suppressed, and the inhibition of adhesion to the matrix resin due to the thermal decomposition can be suppressed. Here, the matrix resin means a matrix resin made of a thermosetting resin or a thermoplastic resin, and may contain one or more kinds. There is no restriction | limiting in particular as a thermosetting resin, An epoxy resin, a phenol resin, unsaturated polyester resin, vinyl ester resin, cyanate ester resin, a polyimide resin etc. are mentioned. The thermoplastic resin is not particularly limited, and polyolefin resin, polyamide resin, polycarbonate resin, polyester resin, polyacetal resin, ABS resin, phenoxy resin, polymethyl methacrylate resin, polyphenylene sulfide resin, polyetherimide resin, poly Ether ketone resin etc. are mentioned. Among these, thermoplastic resins are preferable, and polyamide resins are more preferable, from the viewpoint that the adhesive improvement effect by the sizing agent of the present invention is higher. Here, the polyamide resin is a polymer compound having a plurality of amide groups in its main chain, which is synthesized from a dibasic fatty acid and a diamine, an ω-amino acid, a lactam or a derivative thereof, and a homopolymer or copolymer ( Copolymers etc. are also included. Moreover, the modified body which introduce | transduced the substituent into the principal chain or the terminal may be sufficient.
These matrix resins may be partially or entirely modified for the purpose of further improving the adhesion to 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 fabric sheets, and other filament winding molding can be adopted.
When kneading the thermoplastic matrix resin and the reinforcing fiber, if the thermoplastic matrix resin has a high melting point such as a general purpose engineer plastic or super engineer plastic, it is kneaded with the reinforcing fiber at a temperature of 200 ° C. to 400 ° C. Manufacture fiber reinforced composite materials.
The content of the reinforcing fiber strand and the reinforcing fiber chopped strand in the fiber-reinforced composite material is not particularly limited, and may be appropriately selected depending on the type of fiber, the form, the type of matrix resin, etc. On the other hand, 5 to 70% by weight is preferable, and 20 to 60% by weight is more preferable.

  Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to the examples described herein. Unless otherwise specified, percentages (%) and parts shown in the following examples indicate "wt%" and "parts by weight". The measurement of each characteristic value was performed based on the method shown below.

<Dynamic surface tension>
The sizing agent is diluted with water so as to be a 2% by weight non-volatile content aqueous solution, and a bubble pressure interval (bubble plate) 20 at 25 ° C. using a bubble pressure dynamic surface tension meter (BP-2, manufactured by KURSS) The dynamic surface tension measurement was performed in the range of -1000 msec, and the dynamic surface tension measurement value at a bubble generation interval (bubble plate) 100 msec was read.

<Weight loss rate>
The sizing agent is heat-treated at 105 ° C. to remove the solvent and the like to reach a constant weight to obtain the non-volatile content of the sizing agent. About 4 mg of the obtained non-volatile content was taken in a known weight aluminum pan, and the weight (W ₁ ) was measured. The non-volatile matter contained in the aluminum pan is set in a differential thermal balance TG-8120 (manufactured by RIGAKU CO., LTD.) And heated from 25 ° C. to 500 ° C. in air at a heating rate of 20 ° C./min. (W ₂ ) was measured. Thereafter, the weight reduction rate was calculated by the following equation.
Weight reduction rate (%) = ((W _1- W ₂ ) / W ₁ ) × 100

<Adhesiveness>
The adhesive property was evaluated by the micro droplet method using a composite material interface property evaluation device HM410 (manufactured by Toei Sangyo Co., Ltd.).
A carbon fiber filament is taken out from the carbon fiber strand manufactured by the Example and the comparative example, and it sets to the composite material interface characteristic evaluation apparatus. A drop of polyamide resin T-663 (made by Toyobo Co., Ltd.) melted on an apparatus was formed on a carbon fiber filament, and sufficiently cooled at room temperature to obtain a sample for measurement. The measurement sample was again set in the apparatus, the drop was sandwiched by the apparatus blade, the carbon fiber filament was run on the apparatus at a speed of 0.06 mm / min, and the maximum drawing load F when drawing the drop from the carbon fiber filament was measured. .
The interfacial shear strength τ was calculated by the following equation to evaluate the adhesion between the carbon fiber filament and the polyamide resin.
Interfacial shear strength τ (unit: MPa) = F / π dl
(F: Maximum withdrawal load d: Carbon fiber filament diameter l: Particle diameter in the drop withdrawal direction)

<Handling test (strand focusing)>
Sizing agent A sizing agent was attached to the untreated carbon fiber strand (fineness 700 tex, 12000 filaments) in such a manner that the adhesion amount of the non-volatile matter of the sizing agent was 2.0% by weight. The convergence of the obtained attached carbon fiber strand (length: about 50 cm) was measured with a texture tester (HANDLE-O-METERHOM-2 manufactured by Daiei Kagaku Seiki Mfg. Co., Ltd., slit width 20 mm).
The measurement was performed 10 times, and the larger the average value, the better the convergence of the carbon fiber strand was judged.
(Judgment criteria)
◎: 60 g or more The carbon fiber strand is very hard, and the carbon fiber strand is very well gathered.
○: less than 60 g, 50 g or more The carbon fiber strand is hard, and the carbon fiber strand has good integrity.
X: less than 50 g The carbon fiber strand is soft and the carbon fiber strand is poorly gathered.

<Chopped strand convergence>
Sizing agent A sizing agent was attached to the untreated carbon fiber strand (fineness 700 tex, 12000 filaments) in such a manner that the adhesion amount of the non-volatile matter of the sizing agent was 2.0% by weight. The attached carbon fiber strand obtained was cut into a length of about 6 mm by a rotary cutter to produce a chopped strand. The 50 chopped strands were checked visually for free fibers, loosening and cracks, and the chopped strands in which the occurrence was observed were regarded as defects, and the smaller the number of defects, the better the convergence of the chopped strands. I judged.
(Judgment criteria)
◎: The number of defects is 0 or more, 2 or less. The convergence of the carbon fiber chopped strands is very good.
○: The number of defects is 2 or more and 10 or less. The convergence of the carbon fiber chopped strands is good.
X: The number of defects is more than 10 The convergence of carbon fiber chopped strands is poor.

[Synthesis of polyester polyol]
Synthesis Example 1
While sealing nitrogen gas in a reactor, 605.6 parts of terephthalic acid, 600.6 parts of isophthalic acid, 256.0 parts of ethylene glycol, 437.4 parts of neopentyl glycol and 0.3 parts of dibutyl tin oxide as a catalyst are charged. The esterifying reaction was carried out at 190 to 240 ° C. for 10 hours to obtain an aromatic polyester polyol B1-1 having a number average molecular weight of 1,800 and a hydroxyl value of 62 mg KOH / g.

(Composition examples 2 to 6)
Aromatic polyester polyols B1-2 to B1-4, aliphatic polyester polyols X-1 to X, using the same method as in Synthesis Example 1 except that the raw materials and the amounts thereof were changed to those shown in Table 1 -2 was obtained respectively.

[Synthesis of aromatic polyester-based urethane resin]
(Production Example U1)
In a four-necked flask equipped with a thermometer, a stirrer, and a reflux condenser, add 169.93 parts of the aromatic polyester polyol B1-1 prepared above as the aromatic polyester polyol (B1), and reduce the pressure to 120-130 ° C. Dewatered in the Then, it is cooled to 50 ° C., and 37.76 parts of polyethylene glycol (number average molecular weight 400) as polyalkylene glycol (B5) and 7.60 parts of trimethylolpropane as active hydrogen group-containing compound (B4) having three or more functions And 100 parts of methyl ethyl ketone and 0.5 parts of triethylenediamine as a catalyst. After sufficiently stirring and mixing, 63.52 parts of hexamethylene diisocyanate as an organic polyisocyanate compound (A) was added, and the mixture was heated to 75 ° C. and reacted for 2 hours to obtain a prepolymer solution having a terminal isocyanate group. After completion of the reaction, the reaction solution is cooled to 40 ° C., and 7.60 parts of 2,2-bis (hydroxyethyl) propionic acid, a tertiary amine compound having an active hydrogen group as an active hydrogen group-containing compound (B3) having a carboxyl group 11.25 parts of N-methyldiethanolamine as B2) and 2.34 parts of ethylene glycol as another active hydrogen group-containing compound (B6) were added and reacted at 75 ° C. for 2 hours. After completion of the reaction, the reaction solution was cooled to 40 ° C., and 5.73 parts of triethylamine as a basic component was added thereto for neutralization reaction, and then 1200 parts of water was added to obtain an aqueous dispersion. The obtained aqueous dispersion was subjected to reduced pressure treatment at 65 ° C. to remove methyl ethyl ketone by distillation to adjust the water content to obtain an aqueous dispersion of aromatic polyester urethane resin U1 having a nonvolatile content of 20% by weight.

(Production Examples U2 to U22)
Organic polyisocyanate compound (A), aromatic polyester polyol (B1), tertiary amine compound (B2) having active hydrogen group, active hydrogen group-containing compound (B3) having carboxyl group, trifunctional or higher active hydrogen group containing The same as in Production Example U1 except that the compound (B4), the polyalkylene glycol (B5), the other active hydrogen group-containing compound (B6), and the basic component (D) are changed to those described in Table 2 and parts by weight. Thus, an aqueous dispersion of an aromatic polyester-based urethane resin U2 to U22 having a nonvolatile content of 20% by weight was obtained.

[Synthesis of Urethane Resin for Comparative Example]
(Production Examples Z1 to Z12)
Organic polyisocyanate compound (A), aromatic polyester polyol (B1), tertiary amine compound (B2) having active hydrogen group, active hydrogen group-containing compound (B3) having carboxyl group, trifunctional or higher active hydrogen group containing The same as in Production Example U1 except that the compound (B4), the polyalkylene glycol (B5), the other active hydrogen group-containing compound (B6), and the basic component (D) are changed to those described in Table 3 and parts by weight Thus, an aqueous dispersion of aromatic polyester urethane resins Z1 to Z5, Z11 and Z12, and aliphatic polyester urethane resins Z6 to Z10 having a nonvolatile content of 20% by weight was obtained. The aromatic polyester-based urethane resins Z11 and Z12 use a primary or secondary amine compound having an active hydrogen group instead of the tertiary amine compound (B2) having an active hydrogen group.

  Tables 2 and 3 show parts by weight of the organic polyisocyanate compound (A), the active hydrogen group-containing compound (B), and the basic component (D) which constitute the urethane resin. Moreover, the component of Table 2, 3 is shown below.

Organic polyisocyanate compound (A)
A-1: Hexamethylene diisocyanate
A-2: Isophorone diisocyanate A-3: Dicyclohexylmethane 4,4'-diisocyanate A-4: A tertiary amine compound having an active hydrogen group of 4,4'-diphenylmethane diisocyanate (B2)
B2-1: N-methyldiethanolamine
B2-2: N-ethyl diethanolamine
B2-3: triethanolamine B2-4: N, N-dimethylethanolamine B2-5: N, N-diethylisopropanolamine
Active hydrogen group-containing compound having a carboxyl group (B3)
B3-1: 2, 2-bis (hydroxyethyl) propionic acid B3-2: active hydrogen group-containing compound having a functionality of 2, 2-bis (hydroxymethyl) butanoic acid (B4)
B4-1: trimethylolpropane B4-2: pentaerythritol
Polyalkylene glycol (B5)
B5-1: polyethylene glycol number average molecular weight 400
B5-2: polypropylene glycol number average molecular weight 600
B5-3: polytetramethylene glycol number average molecular weight 1000
Other active hydrogen group-containing compounds (B6)
B6-1: Ethylene glycol B6-2: 1,4-butanediol basic component (D)
D1: Triethylamine D2: Triethanolamine D3: 25% ammonia water D4: N, N-Dimethylethanolamine
Primary or Secondary Amine Compound Having Active Hydrogen Group (Y)
Y-1: ethanolamine Y-2: N-hydroxyethyl laurylamine

[Preparation of water dispersion (E1 to E5) of other resin component (E)]
(Epoxy resin water dispersion (E1))
JER1001 (Japan Epoxy Resins Co., Ltd., solid bisphenol A epoxy resin, epoxy equivalent 450 to 500) / JER 828 (Japan Epoxy Resins Co., Ltd., liquid bisphenol A epoxy resin, epoxy equivalent: 184 to 194) / ethylene oxide A composition consisting of 150 mol addition-cured castor oil ether = 45/35/20 (weight ratio) is charged in an emulsifying apparatus, stirred sewage is gradually added to cause phase inversion emulsification, and an epoxy resin water dispersion having a nonvolatile content of 30% by weight I got E1).

(Vinyl ester resin water dispersion (E2))
A composition consisting of bisphenol A diglycidyl ether acrylic acid adduct / ethylene oxide 150 mole addition-cured castor oil ether = 75/25 (weight ratio) is charged in an emulsifying device, stirring wastewater is gradually added, phase inversion emulsification is carried out, and non volatile matter A 25% by weight unsaturated polyester water dispersion (E2) was obtained.

(Saturated polyester resin water dispersion (E3))
While nitrogen gas is sealed in a reactor, 166 parts of isophthalic acid, 127 parts of diethylene glycol, 10 parts of dimethyl sodium 5-sulfoisophthalate, 0.1 parts of zinc acetate and 0.5 parts of antimony trioxide are charged, and 140 to 220 ° C. The reaction was performed for 3 hours. Then, the polycondensation reaction was performed at 240-270 degreeC under pressure reduction for 10 hours. 160 parts of the obtained saturated polyester resin and 40 parts of ethylene glycol monobutyl ether were charged in an emulsifying apparatus, and stirred at 150 to 170 ° C. to homogenize. Subsequently, 800 parts of stirred sewage was gradually added to obtain a polyester resin water dispersion (E3) having a nonvolatile content of 20% by weight.

(Unsaturated polyester resin water dispersion (E4))
While nitrogen gas was being enclosed in a reactor, 100 parts of maleic anhydride and 410 parts of ethylene oxide 4-mole adduct of bisphenol A were reacted at 140 ° C. for 5 hours to obtain unsaturated polyester with an acid value of 4. Next, a composition comprising the obtained unsaturated polyester / ethylene oxide 150 mole addition-cured castor oil ether = 80/20 (weight ratio) is charged into an emulsifying apparatus, stirred sewage is gradually added, phase inversion emulsification is carried out, and non volatile matter A 20% by weight unsaturated polyester resin water dispersion (E4) was obtained.

(Polyamide resin water dispersion (E5))
140 parts of polyether diamine (molecular weight 500), 31 parts of adipic acid, 45 parts of ε-caprolactam and 0.5 parts of p-toluenesulfonic acid are charged in a reactor under nitrogen gas sealing, and 13 at 220 ° C. with stirring. Polycondensation was carried out for a time to obtain a polyamide resin. 150 parts of the obtained polyamide resin was charged into an emulsifying apparatus, and 850 parts of stirred sewage was gradually added to obtain a polyamide resin water dispersion (E5) having a nonvolatile content of 15%.

(Examples 1 to 42, Comparative Examples 1 to 20)
Aqueous dispersions of aromatic polyester-based urethane resins U1 to U22, aromatic polyester-based urethane resins Z1 to Z5, Z11, Z12, aliphatic polyester-based urethane resins Z6 to Z10 and other resin components (E) and the following: The components shown in Table 1 were mixed and stirred so as to have the nonvolatile components shown in Tables 4 to 7 and diluted with water to adjust the sizing agent having a nonvolatile content concentration of 10% by weight. The numerical values in Tables 4 to 7 show the weight proportions of the respective components (in the case of the aqueous dispersion, the nonvolatile matter) in the nonvolatile matter of the sizing agent. For example, the numerical value of U1 in Table 4 indicates the weight ratio of the non-volatile component of the water dispersion of the aromatic polyester urethane resin U1 to the non-volatile component of the sizing agent. The obtained sizing agent was used to evaluate the feeling test, strand convergence, chopped strand convergence, weight loss rate, dynamic surface tension by the above-mentioned method. The results are shown in Tables 4-7.

Polyoxyalkylene alkyl ether (C)
C1: 2-EO 4 molar adduct of 2-ethylhexyl alcohol C 2: PO 6 molar adduct of 2-ethylhexyl alcohol C 3: C 12-14 EO 7 molar adduct of secondary alcohol C 4: EO 9 molar adduct of tridecyl alcohol

  Next, after immersing and impregnating a sizing agent untreated carbon fiber strand (fineness 700 tex, 12000 filaments) in the prepared sizing agent, hot air drying is carried out at 105 ° C. for 15 minutes, and the adhesion amount of sizing agent non-volatile content is A sizing agent-treated carbon fiber strand was obtained which was 5% by weight with respect to the carbon fiber strand. For the present strand, matrix resin adhesion was evaluated by the method described above. These results are shown in Tables 4 and 5.

As can be seen from Tables 4 and 5, in Examples 1 to 35, the urethane resin in the sizing agent is a structural unit derived from the aromatic polyester polyol (B1) and a tertiary amine compound (B2) having an active hydrogen group. Since it has a constituent unit derived from the above and a constituent unit derived from an active hydrogen group-containing compound (B3) having a carboxyl group, it is excellent in excellent strand bundling ability, excellent chopped strand bundling ability, and matrix resin. It has adhesiveness.
On the other hand, when the urethane resin in the sizing agent does not have a structural unit derived from an active hydrogen group-containing compound (B3) having a carboxyl group (Comparative Examples 1 and 2), a tertiary amine compound (B2) having an active hydrogen group When it does not have a structural unit derived from) (comparative examples 3 and 4), it is derived from an active hydrogen group-containing compound (B3) having a structural unit derived from a tertiary amine compound (B2) having an active hydrogen group and a carboxyl group When the urethane resin has a structural unit derived from an aliphatic polyester polyol (X) instead of a structural unit derived from an aromatic polyester polyol (B1) (Comparative Examples 5 to 7) Comparative Examples 8 to 12), a primary or urethane resin having an active hydrogen group instead of a constituent unit derived from a tertiary amine compound (B2) having an active hydrogen group The case of having a structure unit derived from a secondary amine compound (Y) (Comparative Example 13 to 15), one object of the present invention can not be resolved.

As can be seen from Tables 6 and 7, in Examples 36 to 42, the sizing agent is composed of an aqueous dispersion of the above-mentioned aromatic polyester-based urethane resin and other resin component (E) and / or a polyoxyalkylene alkyl ether. Thus, it has excellent strand convergence, excellent chopped strand convergence and excellent adhesion to the matrix resin.
On the other hand, in Comparative Examples 16 to 20, since the sizing agent is an aqueous dispersion of the other resin component (E) and does not contain the above-mentioned aromatic polyester urethane resin, any of the problems of the present invention can not be solved.

  Fiber reinforced composite materials in which a matrix resin is reinforced with reinforcing fibers are used in automotive applications, aerospace and space applications, sports and leisure applications, general industrial applications, and the like. Examples of the reinforcing fiber include various inorganic fibers such as carbon fiber, glass fiber and ceramic fiber, and various organic fibers such as aramid fiber, polyamide fiber and polyethylene fiber. The sizing agent of the present invention can be suitably used for reinforcing fibers for reinforcing a matrix resin.

Claims (11)

Essentially contains an aromatic polyester-based urethane resin,
The aromatic polyester-based urethane resin is a reaction product of an organic polyisocyanate compound (A) and an active hydrogen group-containing compound (B),
The active hydrogen group-containing compound (B) essentially comprises an aromatic polyester polyol (B1), a tertiary amine compound (B2) having an active hydrogen group, and an active hydrogen group-containing compound (B3) having a carboxyl group.
Reinforcing fiber sizing agent.   When the constituent unit derived from the aromatic polyester polyol (B1) in the aromatic polyester-based urethane resin is 100 moles, the ratio of the constituent unit derived from the tertiary amine compound (B2) having the active hydrogen group is The sizing agent for reinforcing fibers according to claim 1, which is 0.1 to 1000 mol, and the proportion of the constituent unit derived from the active hydrogen group-containing compound (B3) having a carboxyl group is 0.1 to 1000 mol. .   When the constituent unit derived from the tertiary amine compound (B2) having the active hydrogen group in the aromatic polyester urethane resin is 100 moles, it is derived from the active hydrogen group-containing compound (B3) having the carboxyl group The sizing agent for reinforcing fibers according to claim 1 or 2, wherein the proportion of constituent units is 0.5 to 20000 mol.   The active hydrogen group-containing compound (B) is a compound other than the aromatic polyester polyol (B1), the tertiary amine compound (B2) having an active hydrogen group, and the active hydrogen group-containing compound (B3) having a carboxyl group. The sizing agent for reinforcing fibers according to any one of claims 1 to 3, which comprises an active hydrogen group-containing compound (B4) having three or more functions. The tertiary amine compound (B2) having an active hydrogen group is at least one selected from a compound represented by the following general formula (1) and a compound represented by the following general formula (2): The sizing agent for reinforcing fibers according to any one of the above.

(In formula (1), R ¹ is a hydrocarbon group having 1 to 20 carbon atoms. A ¹ O is an oxyalkylene group having 2 to 4 carbon atoms. A is a number from 1 to 20. m is It is a number from 0 to 2. When there are a plurality of R ¹ and (A ¹ O) a in the molecule, they may be the same or different from each other.)

(In the formula (2), R ² is a hydrocarbon group having 1 to 20 carbon atoms. A ² is a hydrocarbon group having 1 to 10 carbon atoms. N is a number from 1 to 2. When there are a plurality of R ² and A ² , they may be identical to or different from each other.)   The sizing agent for reinforcing fibers according to any one of claims 1 to 5, wherein the active hydrogen group-containing compound (B) further contains a polyalkylene glycol (B5) having a number average molecular weight of 100 to 2,000.   The sizing agent for reinforcing fiber according to any one of claims 1 to 6, further comprising a polyoxyalkylene alkyl ether (C) which is an alkylene oxide adduct of a C4 to C20 monohydric alcohol.   The sizing agent for reinforcing fibers according to any one of claims 1 to 7, wherein the reinforcing fibers are carbon fibers.   A reinforcing fiber strand in which the reinforcing fiber sizing agent according to any one of claims 1 to 8 is attached to a raw material reinforcing fiber strand.   A reinforced fiber chopped strand obtained by cutting a reinforced fiber strand having the reinforcing fiber sizing agent according to any one of claims 1 to 8 attached to a raw material reinforced fiber strand.   A fiber reinforced composite material comprising a matrix resin and the reinforcing fiber strand according to claim 9 and / or the reinforcing fiber chopped strand according to claim 10.