JP2007145609A - Glass fiber sizing agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glass fiber sizing agent giving glass fiber-reinforced plastics having excellent impact resistance. <P>SOLUTION: The glass fiber sizing agent comprises an aqueous dispersion of a polyurethaneurea resin, and the polyurethaneurea resin satisfies all of the following conditions (1) to (3): the condition (1) where a urethane prepolymer having terminal isocyanate groups used for the production of the polyurethaneurea resin is obtained by reacting a polyol with the number average molecular weight of 500 to 4,000, a polyol with the number average molecular weight of 100 to <500 having carboxy groups or epoxy groups, and polyisocyanate; the condition (2) where the polyurethaneurea resin is obtained by dispersing the urethane prepolymer having terminal isocyanate groups into water in the presence of an emulsifier, and simultaneously with the dispersing or after the dispersing, performing chain extension with water and/or polyamine; and the condition (3) where the content of the carboxy groups or epoxy groups based on the weight of the polyurethaneurea resin is 0.1 to 1.2 wt.%. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a glass fiber sizing agent comprising an aqueous dispersion of a polyurethane urea resin in which a urethane prepolymer is dispersed in water in the presence of an emulsifier and chain-extended with water or polyamine.

Glass fibers are inherently brittle and can be easily cut when damaged by impacts such as friction. For this reason, various glass fiber sizing agents have been used in the past to protect glass fibers from friction during winding, twisting, pipe winding and weaving in the production process of glass fibers, and to prevent fluffing and yarn breakage. Has been. Conventionally, as a sizing agent for glass fibers, starch, processed starch, dextrin, amylose and other starches, carboxymethylcellulose, polyvinyl alcohol, acrylamide-vinyl acetate copolymer, aqueous polyurethane resin (for example, Patent Document 1), etc. are synthesized. Although polymer compounds have been used, it cannot be said that glass fiber fluff generation is sufficiently suppressed because the dry film formed is hard and brittle.
On the other hand, a glass fiber sizing agent in which a urethane prepolymer is dispersed in water by combining specific emulsifiers has been proposed (see Patent Document 2).
Further, a glass fiber sizing agent containing a polyurethane urea resin aqueous dispersion and a specific water-soluble polymer compound has been proposed (see Patent Document 3).
Japanese Patent Publication No.52-6393 JP-A-11-236248 JP 2001-19496 A

  However, although these (Patent Documents 2 and 3) suppress the occurrence of glass fiber fluff, the compatibility between the resin film to be formed and the matrix resin is poor, and it can be said that the physical properties of the glass fiber reinforced plastic are sufficient. However, there was a problem that the impact resistance was insufficient.

  As a result of various studies to solve the above problems, the present inventors have obtained a glass fiber obtained by applying a glass fiber sizing agent using an aqueous dispersion of a polyurethane urea resin having a specific functional group. It was found that the glass fiber reinforced plastic produced using the fiber was excellent in impact resistance, and the present invention was achieved.

That is, the present invention is a glass fiber sizing agent containing an aqueous dispersion of a polyurethane urea resin (U), and the polyurethane urea resin (U) satisfies all of the following (1) to (3). It is a sizing agent for glass fiber.
(1): Number average of terminal isocyanate group urethane prepolymer (A) used for production of polyurethane urea resin (U) having a polyol (A1), carboxyl group or epoxy group having a number average molecular weight of 500 to 4,000. It is a terminal isocyanate group urethane prepolymer obtained by reacting a polyol (A2) having a molecular weight of 100 or more and less than 500 and a polyisocyanate (A3).
(2): Polyurethane urea resin (U) is dispersed with water and / or polyamine at the same time or after dispersing terminal isocyanate group urethane prepolymer (A) in water in the presence of emulsifier (B). This is a polyurethane urea resin obtained by stretching.
(3): The carboxyl group or epoxy group content based on the weight of the polyurethane urea resin (U) is 0.1 to 1.2% by weight.

  The glass fiber sizing agent containing the aqueous dispersion of the polyurethane urea resin of the present invention can improve the impact resistance strength of the obtained FRP, FRTP, and the like as compared with the glass fiber using the conventional sizing agent.

  The polyurethane urea resin (U) in the present invention is characterized by satisfying any of the following (1) to (3).

(1): Number average of terminal isocyanate group urethane prepolymer (A) used for production of polyurethane urea resin (U) having a polyol (A1), carboxyl group or epoxy group having a number average molecular weight of 500 to 4,000. It is a terminal isocyanate group urethane prepolymer obtained by reacting a polyol (A2) having a molecular weight of 100 or more and less than 500 and an aliphatic polyisocyanate (A3).
(2): Polyurethane urea resin (U) is dispersed with water and / or polyamine at the same time or after dispersing terminal isocyanate group urethane prepolymer (A) in water in the presence of emulsifier (B). This is a polyurethane urea resin obtained by stretching.
(3): The carboxyl group or epoxy group content based on the weight of the polyurethane urea resin (U) is 0.1 to 1.2% by weight.

  In the present invention, the urethane prepolymer (A) includes a polyol (A1) having a number average molecular weight of 500 to 4,000, a polyol (A2) having a carboxyl group or an epoxy group and having a number average molecular weight of 100 or more and less than 500, and an aliphatic system. It is a terminal isocyanate group urethane prepolymer obtained by reacting polyisocyanate (A3).

Specific examples of (A1) include, for example, polyester polyol (for example, polyethylene adipate diol, polybutylene adipate diol, polyethylene butylene adipate diol, polyneopentyl adipate diol, polyneopentyl terephthalate diol, polycaprolactone diol, polyvalerolactone diol, poly Such as hexamethylene carbonate diol); polyether polyols [polyethylene glycol, polypropylene glycol, polyoxyethyleneoxypropylene glycol, polyoxytetramethylene glycol, EO and / or propylene oxide (hereinafter abbreviated as PO) adducts of bisphenols, etc.] Can be mentioned.
Among (A1), polybutylene adipate diol, polyethylene butylene adipate diol, polypropylene glycol, and polyoxyethyleneoxypropylene glycol are preferable from the viewpoint of being not brittle and durable (suppressing generation of fluff).
The number average molecular weight (hereinafter abbreviated as Mn: measured by GPC) of (A1) is usually 500 to 4,000, preferably 800 to 3,000 from the viewpoint of being not brittle and durable (suppressing generation of fluff). is there.

Examples of the polyol (A2) having Mn of 100 or more and less than 500 having a carboxyl group or an epoxy group include lactic acid, hydroxybutyric acid, 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, 2,2-dimethylolheptane. Examples thereof include a polyol (A21) having a carboxyl group such as acid and tartaric acid, and a polyol (A22) having an epoxy group such as glycerin monoglycidyl ether and trimethylolpropane monoglycidyl ether. Among (A2), preferred are dimethylolpropionic acid, dimethylolbutanoic acid, and glycerin monoglycidyl ether from the viewpoint of containing a carboxyl group or an epoxy group in a small amount.
The amount of (A2) used is related to the content of carboxyl groups or epoxy groups in the polyurethane urea resin (U).
In the present invention, the content of the carboxyl group or epoxy group in the polyurethane urea resin (U) is 0.1 to 1.2% (in the following, unless otherwise specified,% represents% by weight) The weight of (A2) in the polyurethane urea resin (U) is usually 0.2 to 6.0%, preferably 0.3 to 5.0%.
If necessary, a compound containing a hydrophilic group and an active hydrogen group in the molecule (for example, aminoethylsulfonic acid) may be used in combination.

  Examples of the polyisocyanate (A3) include 2,4′- or 4,4′-diphenylmethane diisocyanate (MDI), 2,4- or 2,6-tolylene diisocyanate (TDI), 4,4′-dibenzyl. Aromatic diisocyanates such as diisocyanate, 1.3- or 1,4-phenylene diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate; aliphatic diisocyanates such as ethylene diisocyanate, hexamethylene diisocyanate (HDI), lysine diisocyanate; Alicyclic diisocyanates such as forone diisocyanate (IPDI), 4,4′-dicyclohexylmethane diisocyanate; and mixtures of two or more thereof. Among these, HDI, IPDI and 4,4'-dicyclohexylmethane diisocyanate are preferable from the viewpoint of yellowing resistance.

The chain extender and crosslinking agent used as necessary include active hydrogen-containing compounds having an Mn of 60 to less than 500, such as polyhydric alcohols [ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4-butanediol, 1,6-hexanediol, 3-methylpentanediol, diethylene glycol, neopentyl glycol, 1,4-bis (hydroxymethyl) cyclohexane, 1,4-bis (hydroxyethyl) benzene, 2,2-bis (4,4 Dihydric alcohols such as' -hydroxycyclohexyl) propane; Trihydric alcohols such as glycerin and trimethylolpropane; pentaerythritol, diglycerin, α-methylglucoside, sorbitol, xylit, mannitol, dipentaerythritol -Glucose, glucose, Lactose, 4- to 8-valent alcohols such as sucrose], polyphenols (polyphenols such as pyrogallol, catechol, hydroquinone; bisphenol A, bisphenol F, bisphenol Bisphenols such as S), water, polyamines (aliphatic polyamines (ethylenediamine, hexamethylenediamine, diethylenetriamine, etc.), alicyclic polyamines (isophoronediamine, 4,4′-dicyclohexylmethanediamine, etc.), aromatic polyamines (Such as 4,4′-diaminodiphenylmethane), aromatic alicyclic polyamines (such as xylylenediamine), hydrazine or derivatives thereof, and the like.
Moreover, you may use a chain terminator as needed, As a chain terminator, C1-C8 monoalcohol (Methanol, ethanol, isopropanol, cellosolve, carbitols, etc.), C1-C10 And monoamines (mono- or dialkylamines such as monomethylamine, monoethylamine, monobutylamine, dibutylamine; mono- or dialkanolamines such as monoethanolamine and diethanolamine).

  In the present invention, the production method (A) is not particularly limited, and can be obtained by a urethanization reaction using the above raw materials in a method for producing a normal urethane prepolymer (one-shot method or multistage method). The reaction temperature for urethanization is usually 30 to 200 ° C, preferably 50 to 180 ° C. The reaction time is usually 0.1 to 30 hours, preferably 0.1 to 8 hours.

  The urethanization reaction is usually performed in a solventless system or in an organic solvent inert to the polyisocyanate. Examples of the organic solvent include acetone, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide, toluene, dioxane, acetic acid ethyl ester, and the like.

  In the urethanization reaction, the ratio of the isocyanate equivalent in the polyisocyanate to the equivalent of the active hydrogen group contained in the polyols (A1) and (A2) is usually 0.9 to 3, preferably 1.1 to 2. Especially preferably, it is 1.2-1.6. The isocyanate group content in the polyurethane resin obtained by the urethanization reaction is usually 0 to 10% (in the following, unless otherwise specified,% represents% by weight), preferably 0.5 to 10%. It is.

  The polyurethane urea resin (U) in the present invention is prepared by dispersing the above-mentioned terminal isocyanate group urethane prepolymer (A) in water in the presence of an emulsifier (B) or after being dispersed in water and / or polyamine. It is a polyurethane urea resin obtained by chain extension.

The emulsifier (B) is not particularly limited as long as it is an emulsifier conventionally used as an emulsifier for a urethane prepolymer.
Preference is given to using two types of emulsifiers having different ranges of HLB in combination.
One of the two types of emulsifiers used in combination is a water-soluble polyurethane emulsifier (B1) having an HLB of 13 to 40, preferably 13 to 30, particularly preferably 13 to 20, and one other type of emulsifier. The HLB of (B2) is 8 or more and less than 13, preferably 9 or more and less than 13, particularly preferably 9.5 or more and less than 13.
By using two types of emulsifiers having such a range of HLB, the mechanical stability of the aqueous dispersion is improved, and the impact resistance imparting effect as a sizing agent for glass fibers is improved. .
HLB can be calculated from the concept of organic and inorganic properties of organic compounds ["Introduction to New Surfactants" by Takehiko Fujimoto, published by Sanyo Chemical Industries, p197-201].
The weight average molecular weight (measured by GPC, hereinafter abbreviated as Mw) of (B1) is 5,000 to 500,000, preferably 5,000 to 400,000, more preferably 5,000 to 200,000. is there.

Mw of (B2) is 500 to 20,000, preferably 800 to 15,000, and more preferably 1,000 to 10,000.
When the Mw of (B1) is less than 5,000 or the Mw of (B2) is less than 500, the resulting aqueous dispersion has insufficient mechanical stability, and the scum of the sizing agent comprising the aqueous dispersion is generated and the fibers are cut. If the Mw of (B1) exceeds 500,000 or the Mw of (B2) exceeds 20,000, the sizing agent becomes highly viscous when used as a sizing agent component, and the glass fiber Difficult to apply sizing agent

  (B1) is an emulsifier having a polyurethane structure, and is water-soluble (solubility at 25 ° C. is 1 or more).

  Preferable among (B1) is an emulsifier (B11) represented by the following general formula (1) described in JP-A-2005-120282.

In the formula, R ¹ is a residue obtained by removing the hydroxyl group of k-valent alcohol or phenol, X is a residue of organic diisocyanate, R ² is a residue obtained by removing the hydroxyl group of divalent alcohol or phenol, Z Is —O (AO) mR ¹ [(OA) mOH] k-1 and / or —N (R ³ ) ₂ (wherein at least one of R ³ is a hydrocarbon group having 1 to 100 carbon atoms or a hydroxyl group-containing carbon atom) A is a hydrogen group and the rest are hydrogen atoms.), A is an alkylene group having 2 to 30 carbon atoms (provided that m, n and p oxyalkylene groups AO are composed of two or more oxyalkylene groups). The bonding mode in the case may be either block or random.), M, n and p are each independently 0 or an integer from 1 to 150 (provided that the sum of all m, n and p in {} is At least 10 and R ¹ is phenols In the case of a residue, m is not 0, and when R ² is a phenol residue, n and p are not 0. Also, a plurality of m, p, R ¹ , X, R ² , and R ³ are the same. Or q may be 0 or an integer of 1 to 150, and k may be an integer of 1 to 6.

Examples of the 1-6 valent alcohols or phenols that give the residue R ¹ include those described in JP-A-2005-120282, and preferred are monovalent or divalent alcohols.
The Mn per hydroxyl group of the alcohols or phenols is usually 30 to 2,000 or more, preferably 30 to 1,000.
Examples of R ² include divalent compounds among those exemplified as R ¹ . The Mn per hydroxyl group is usually 30 to 2,000, preferably 30 to 1,000.
X is a residue of an organic diisocyanate, and the carbon number of X is usually 4-18, preferably 6-15. Examples of the organic diisocyanate include those described above.

  In the general formula (1), examples of A include an ethylene group, a propylene group, a butylene group, and the (poly) oxyalkylene group represented by (AO) m is EO, PO, 1,2-, 1, A group formed by ring-opening (co) addition of an alkylene oxide such as 3- or 2,3-butylene oxide, tetrahydrofuran, or a combination system (random and / or block) of two or more thereof to an alcohol or phenol compound is there. Of these, preferred is a (poly) oxyalkylene group formed by EO alone or by co-addition of EO and PO.

  If m, n, and p are 500 or less, the viscosity of the aqueous solution of the polyurethane-based emulsifier obtained does not become too high, and the emulsification becomes easier. The total of all m, n and p in {} is usually at least 10, preferably 30 to 1,000 or more. If the sum of all m, n, and p in {} is 10 or more, the emulsifiability will not be insufficient because the hydrophilic group portion of the polyurethane emulsifier is large, and the emulsification becomes easier.

Of the Z in the general formula (1), —O (AO) mR ¹ [(OA) mOH] k−1 is preferred, and k is preferably 1, and R ¹ is a monohydric alcohol or monovalent. Residues of phenols, particularly residues of styrenated (1-10 mol addition, preferably 2-5 mol addition) phenol (eg styrenated phenol, styrenated cumylphenol, etc.).
-N (R ³⁾ ₂ of R ³ is at least one 1 to 100 carbon atoms, preferably a hydrocarbon group or a hydroxyl group-containing hydrocarbon group having 8 to 36.
Specific examples of R ³ include residues of monohydric alcohols or monohydric phenols exemplified for R ¹ above, and groups in which at least one of their hydrogen atoms has been substituted with a hydroxyl group, such as hydroxyalkyl groups (2-hydroxyethyl group, 2-hydroxypropyl group, 2-hydroxybutyl group, hydroxyoctyl group and the like) and hydroxyaryl groups (hydroxyphenyl group, 2-methyl-4-hydroxyphenyl group and the like). R ³ may be linear, branched or cyclic, and may be aliphatic or aromatic.
Preferred among R ³ are residues of substituted phenols, and particularly preferred is a residue of styrenated (1 to 10 mol addition, preferably 2 to 5 mol addition) phenol.

In the case where R ¹ , R ² and Z do not have a hydrocarbon group having 10 or more carbon atoms, (poly) oxyalkylene in the general formula (1) from the viewpoint of the emulsifying power of (B1) obtained. At least one of the groups is preferably an oxyalkylene group having 3 or more carbon atoms.

q is usually 0 or an integer of 1 to 150, preferably 1 to 50. If q is 150 or less, the viscosity of the aqueous solution (B1) obtained is low (500,000 mPa · s or less), and emulsification becomes easy.

k is usually an integer of 1 to 6, preferably 1 or 2, especially 1.

(B1) preferably has an average of two or more hydrophobic groups in one molecule, and the difference between the SP value of each of at least two of the hydrophobic groups and the SP value of (A) The absolute value (hereinafter abbreviated as ΔSP1) is preferably 2 or less, particularly 1 or less.
If ΔSP1 is 2 or less, the resulting aqueous dispersion tends to have better mechanical stability, and even when used as a sizing agent component, it is unlikely to cause scum and fiber breakage. ΔSP1 can be adjusted by (B1) selection of the type of hydrophobic group in one molecule. The SP value is calculated by the method of Fedors et al. [Poly. Eng. Sci. 14 (2) 152, (1974)].

Examples of the hydrophobic group contained in (B1) include the aforementioned R ¹ , R ^2, and R ³ , and preferred examples include the same.
In the present invention, X in (B11) represented by the general formula (1) is not included in the hydrophobic group.

  The production method of (B1) in the present invention is not particularly limited, and can be obtained by urethanation of a hydroxyl group-containing compound and an organic diisocyanate by a usual method for producing a polyurethane resin (one-shot method or multistage method).

  In the present invention, the HLB of (B2) used in combination with (B1) is usually 8 or more and less than 13, preferably 9 or more and less than 13, particularly preferably 9.5 or more and less than 13. When the HLB is less than 8 or 13 or more, the resulting aqueous dispersion has poor mechanical stability.

  When the Mw of (B2) is less than 500, the resulting sizing agent has insufficient dilution stability and mechanical stability, which causes scum generation and fiber cutting. If it exceeds 20,000, the resulting sizing agent has a high viscosity. Thus, it becomes difficult to give the sizing agent to the glass fiber.

  Specific examples of (B2) include, for example, (i) nonionic surfactant (for example, higher alcohol EO adduct, alkylphenol EO adduct, fatty acid EO adduct, polyhydric alcohol fatty acid ester EO adduct, higher alkylamine EO addition) , Fatty acid amide EO adduct, fat and oil EO adduct, fatty acid ester of glycerol, fatty acid ester of pentaesitol, fatty acid ester of sorbitol and sorbitan, fatty acid ester of sucrose, alkyl ether of polyhydric alcohol, alkanolamines Fatty acid amides, polyoxyethylene ethers of polypropylene glycol, polyoxyalkylene ethers of polycyclic phenols), (ii) cationic surfactants (eg, alkyltrimethylammonium hydrochloride, alkyldimethylbenzylammonium hydrochloride) Quaternary ammonium salts such as higher alkylamine acetates, etc.) and (iii) amphoteric surfactants (alkylaminopropionic acid alkali metal salts, alkyldimethylbetaines, etc.) Can be mentioned. Of these, nonionic surfactants are preferred, and polyoxyethylene ethers of polypropylene glycol and polyoxyalkylene ethers of polycyclic phenols are particularly preferred.

  (B2) preferably has an average of one or more hydrophobic groups in the molecule, and the absolute value of the difference between the SP value of at least one of the hydrophobic groups and the SP value of (A) ( (Hereinafter abbreviated as ΔSP2) is 2 or less, more preferably 1 or less.

  If ΔSP2 is 2 or less, the resulting aqueous dispersion tends to have better mechanical stability, and even when used as a sizing agent component, it is unlikely to cause scum and fiber breakage. ΔSP2 can be adjusted by (B2) selection of the type of hydrophobic group in one molecule.

Examples of the hydrophobic group contained in (B2) include the aforementioned R ¹ , R ^2, and R ³ , and preferred examples include the same.

The amount of the emulsifier (B) used in the production of the aqueous dispersion in the present invention is usually 0.1 to 20%, preferably 0.5 to 17%, more preferably 2 to 2, based on the weight of (A). 15%, especially 3-12%.
If the amount used is 3% or more, the mechanical stability of the aqueous dispersion tends to be good, and if it is 12% or less, the water resistance of the glass fiber sizing agent using the aqueous dispersion tends to be good.
The ratio of (B1) and (B2) when (B1) and (B2) are used in combination is usually 20/80 to 95/5, preferably 30/70 to 95/5, and more preferably 35/65. ~ 90/10, particularly preferably 40/60 to 80/20. When the ratio of (B1) is 30 to 95, the mechanical stability of the aqueous dispersion is further improved.

The method of dispersing (A) in water to form an aqueous dispersion is not particularly limited.
(i) A method in which (A) and an emulsifier are mixed in advance, and water is gradually added dropwise therein to invert the phase;
(ii) A method in which water in which an emulsifier is dissolved is gradually dropped and dispersed in (A),
(iii) A method in which a mixture of (A) and an emulsifier is dropped and dispersed in water;
(iv) A method in which (A) is dropped and dispersed in water in which an emulsifier is dissolved,
(v) A method in which (A), an emulsifier and water are mixed together and dispersed. Of these, the methods (ii), (iv) and (v) avoid direct contact between the OH groups in water and emulsifiers and the isocyanate groups in (A) while (A) is dispersed in water. Therefore, it is preferable.

The device for dispersing (A) in water is not particularly limited. For example, (i) vertical stirring method, (ii) gear type stirring method, (iii) stator-rotor type method, (iv) high pressure impact method , (V) an ultrasonic impact system, (vi) a kneader having multiple axes such as a kneader. Of these, the methods (i), (iii) and (vi) are preferred.

The aqueous dispersion of polyurethaneurea resin (U) in the present invention is obtained by dispersing (A) in water in the presence of an emulsifier (B) and at the same time extending the chain with water and / or polyamine (i), and A method (ii) obtained by dispersing (A) in water and then extending the chain with water and / or a polyamine. Preferred is (ii).
The temperature of the dispersion | distribution process in the case of (i) and (ii) is 10-40 degreeC normally. Moreover, the temperature of the chain extension process in the case of (ii) is 40-80 degreeC, Preferably it is 45-70 degreeC.
Examples of the chain extender include water, polyamine, and combinations thereof. Examples of the polyamine include water-soluble (poly) alkylene (alkylene group having 2 to 12 carbon atoms) polyamine (such as ethylenediamine, hexamethylenediamine, isophoronediamine and diethylenetriamine), hydrazine derivatives (such as hydrazine, carbodihydrazide and adipic acid dihydrazide) and the like. These two or more types are used in combination. When polyamine is included as a chain extender, the amount of polyamine used is usually 8 parts or less, preferably 0.3 to 5 parts, based on the weight of (A).

In the production of the aqueous dispersion of polyurethane urea resin (U), a chain terminator may be used in combination with a chain extender.
Examples of chain terminators include water-soluble monoamines [primary monoamines having 3 to 8 carbon atoms (for example, n-butylamine, iso-butylamine, sec-butylamine, n-pentylamine, etc.), secondary compounds having 4 to 8 carbon atoms in total. Examples include monoamines (di-n-propylamine, di-n-butylamine, etc.), and primary monoamines, particularly n-butylamine, are preferred. The amount of chain terminator used is usually 5% or less, preferably 3% or less, based on the weight of (A).
Further, the organic solvent used during the urethanization reaction is preferably removed by distillation or the like after dispersing (A) in water and extending the chain.

  Mn of the polyurethane urea resin produced by the above method is usually 2,000 to 2,000,000 or more, preferably 10,000 to 1,500,000.

The solid content concentration of the aqueous dispersion of the polyurethane urea resin (U) in the present invention is usually 10 to 75%, preferably 30 to 60%. The solid content concentration in the present invention is a percentage based on the weight of the aqueous dispersion of the residual weight after 1 to 1.5 g of the sample is heated and dried at 130 ° C. for 90 minutes.
The viscosity of the aqueous dispersion is usually 10 to 10,000 mPa · s, preferably 100 to 5,000 mPa · s. The weight average particle diameter of the aqueous dispersion measured with a laser diffraction / scattering particle size distribution analyzer is usually 10 to 10,000 nm, preferably 100 to 5,000 nm.

In the sizing agent for glass fibers of the present invention, the above aqueous dispersion may be used as it is, but it may be diluted with water as necessary. The content of the polyurethane urea resin (U) in the glass fiber sizing agent of the present invention is usually 0.1 to 20%, preferably 0.5 to 10%.
The sizing agent of the present invention further comprises a kind of resin in which glass fibers are compounded (for example, thermosetting resin such as unsaturated polyester resin and epoxy resin, and thermoplastic resin such as polyamide resin, polyolefin resin and ABS resin). ), If necessary, known additives [for example, coupling agents (aminosilane, vinylsilane, etc.), antistatic agents (cationic or anionic surfactant, etc.), lubricants (cationic surfactant, vegetable wax, etc.), Heat stabilizers, weather stabilizers, antifoaming agents, preservatives, and the like].
The content of these additives is usually 0.2 to 3%, preferably 0.5 to 2% for the coupling agent, and 0 to 0.3% for the antistatic agent, based on the weight of the sizing agent. Preferably 0.05 to 0.2%, lubricant is usually 0 to 0.3%, preferably 0.05 to 0.2%, heat or weather resistance stabilizer, antifoaming agent and preservative are usually 0 to 0 0.3%, preferably 0.05-0.2%. The total content of these additives is usually 0.2 to 4%, preferably 0.6 to 2.1%, based on the weight of the sizing agent, and usually 5 for 100 parts by weight of (A). -200 parts, preferably 20-100 parts.

In the sizing agent of the present invention, the carboxyl group or epoxy group content based on the weight of the polyurethane urea resin (U) is 0.1 to 1.2%, more preferably 0.2 to 0.8%.
By having a carboxyl group or an epoxy group, compatibility with the matrix resin is improved, and the impact strength of glass fiber reinforced plastics such as FRP and FRTP using a glass fiber sizing agent using this aqueous dispersion is good. It becomes.
When the carboxyl group or epoxy group is less than 0.1%, the compatibility with the matrix resin is deteriorated, and the impact resistance of the glass fiber reinforced plastic is lowered. On the other hand, if it exceeds 1.2%, the liquid stability as the sizing agent is deteriorated, and it becomes difficult to apply the sizing agent to the glass fiber.
The method for measuring the carboxyl group content is as follows.

  A sizing agent at 25 ° C. was spread on a glass plate so that the dry film thickness was 200 μm, and was dried by heating at 25 ° C. for 10 hours and at 105 ° C. for 45 minutes. After being immersed in water for 24 hours, washed with water and dried, the water-soluble component is removed, and the component mainly composed of the polyurethane urea resin (U) is taken out. 1.0 to 1.5 g of the extracted component was dissolved in 100 ml of dimethylformamide, and a 1 / 2N hydrochloric acid aqueous solution was added dropwise to adjust the pH in the system to 3 to 4, using a potentiometric titration apparatus. Titrate with an aqueous potassium oxide solution, and calculate the carboxyl group content according to the following formula (1) based on the titration amount from the first inflection point to the second inflection point.

The method for measuring the epoxy group content is as follows.
About 1.0 to 1.5 g of the components taken out in the same manner as described above was dissolved in 25 ml of dimethylformamide, and 25 ml of hydrochloric acid-dimethylformamide solution (mixed with 1.4 ml of reagent primary hydrochloric acid and 100 ml of dimethylformamide) was added. Let stand for reaction. After the reaction, 30 ml of reagent primary methanol is added and titrated with an N / 10 aqueous potassium hydroxide solution using a potentiometric titrator. As a blank test, 50 ml of dimethylformamide and 30 ml of reagent primary methanol are mixed and titrated with an aqueous N / 10 potassium hydroxide solution using a potentiometric titrator. As a correction test, 1.0 to 1.5 g of the extracted component was dissolved in 50 ml of dimethylformamide, 30 ml of reagent primary methanol was added, and titrated with an N / 10 hydrochloric acid aqueous solution if basic using a potentiometric titrator. If it is acidic, it is titrated with an N / 10 potassium hydroxide aqueous solution and obtained from the following formula based on the titration amount up to each inflection point.

However, A: droplets of the study quantitative (ml), B: a drop of the blank test quantitation (ml), S ^1: Sampling of the study (g), D: the correction test titer (ml), S ² : Sampling amount (g) for correction test, correction value is negative for basic and positive for acidic.

  In addition, the viscosity at 25 degreeC of the sizing agent of this invention is 0.1-100 mPa * s normally, Preferably it is 0.5-50 mPa * s.

  The amount of the sizing agent of the present invention applied to the glass fiber is usually 0.1 to 10%, preferably 0.2 to 5%, particularly preferably 0.3 to 3% by weight after drying with respect to the glass fiber. . If it is less than 0.1%, the converging property of the glass fiber is poor, and if it exceeds 10%, the glass fiber becomes too hard, which is not preferable.

  The method for treating the sizing agent with glass fibers is not particularly limited. For example, the glass fibers in a molten state (usually several hundred to several) drawn into fibers from a number of nozzles provided at the lower part of the glass melting furnace. (Thousands) may be bundled by applying a bundling agent with a roll coater, winding it into a cake and drying it.

  Since the sizing agent of the present invention is excellent in compatibility with the matrix resin, it has excellent impact strength when processed into FRP or FRTP.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. In the following, “parts” represents parts by weight, and “%” represents% by weight.

Production Example [Emulsifier (B1)]
Production of emulsifier (B1-1) 90 parts of polyethylene glycol (Mn 20,000), polyoxyethyleneoxypropylene glycol [polypropylene glycol (Mn 1,700) added with EO; Mn 8,500] 77 parts, polytetramethylene ether 3 parts of glycol (Mn 1,000) and 2.2 parts of TDI were reacted at 160 ° C. for 5 hours to obtain an emulsifier (B1-1). (B1-1) has an HLB of 17.3, a hydrophobic group (polyoxypropylene group and polyoxytetramethylene group) with SP values of 8.7 and 9.0, Mw of 95,000, and an intramolecular hydrophobic group, respectively. The average number of the polyoxypropylene group was 2.1 and the polyoxytetramethylene group was 0.7.
Production of emulsifier (B1-2) 15 parts of styrene (2 mol) phenol added with EO (Mn 1,500), 100 parts of polyethylene glycol (Mn 20,000) and 2.6 parts of TDI are reacted at 100 ° C. for 3 hours. To obtain an emulsifier (B1-2). (B1-2) HLB is 18.0, Mw is 40,000, SP value of hydrophobic group (styrenated phenol) is 10.3, and the average number of hydrophobic groups in the molecule is two styrenated phenol groups. there were.

[Emulsifier (B2)]
As the emulsifier (B2), the following was used.
Emulsifier (B2-1): Styrene (2 mol) phenol added with EO (HLB12.3, Mw900, hydrophobic group SP value 10.3)
Emulsifier (B2-2): Polyoxyethyleneoxypropylene glycol [polypropylene glycol (Mn 2,000) with EO added; HLB 10.8, Mw 3,400, SP value 8.7 of hydrophobic part]

[Production Example of Terminal Isocyanate Group Urethane Prepolymer (A)]
Production Example 1
100 parts of polybutylene adipate diol (Mn 1,000), 3 parts of dimethylolpropionic acid and 36 parts of hexamethylene diisocyanate are reacted at 90 ° C. for 4 hours, and the carboxyl group content is 0.7% and the isocyanate group content is 5.6%. A urethane prepolymer (A-1) was obtained. The SP value of the prepolymer was 10.6.
Production Example 2
A urethane prepolymer having a carboxyl group content of 0.7% and an isocyanate group content of 5.2%, obtained by reacting 100 parts of polypropylene glycol (Mn 1,000) with 3 parts of dimethylolpropionic acid and 49 parts of isophorone diisocyanate at 110 ° C. for 5 hours. (A-2) was obtained. The SP value of the prepolymer was 9.4.
Comparative production example 1
100 parts of polypropylene glycol (Mn 1,000) and 34 parts of isophorone diisocyanate were reacted at 110 ° C. for 5 hours to obtain a urethane prepolymer (A-3) having a carboxyl group content of 0% and an isocyanate group content of 3.3%. The SP value of the prepolymer was 9.4.
Comparative production example 2
100 parts of polybutylene adipate diol (Mn 1,000), 10 parts of dimethylolpropionic acid and 52 parts of hexamethylene diisocyanate are reacted at 90 ° C. for 4 hours, and the carboxyl group content is 2.0% and the isocyanate group content is 6.9%. A urethane prepolymer (A-4) was obtained. The SP value of the prepolymer was 10.6.

[Production of aqueous dispersion of polyurethane urea resin]
Production Examples 3-6, Comparative Production Examples 3-5
After cooling 100 parts of the urethane prepolymer described in Table 1 to 30 ° C., simultaneously adding the emulsifier of the amount described in Table 1 and 30 parts of water, mixing and dispersing with a homomixer for about 5 minutes, and then adding 150 parts of water. After adding a solution prepared by dissolving 3 parts of ethylenediamine as a chain extender and n-butylamine 0.3 as a chain terminator in 50 parts of water, the mixture was stirred at 60 ° C. for 5 hours to chain extension and The chain was terminated to obtain an aqueous dispersion of polyurethane urea resin. The analytical values and mechanical stability results of the obtained aqueous dispersion are shown in Table 1.
The evaluation method of the mechanical stability of the aqueous dispersion is as follows.
<Mechanical stability test>
The aqueous dispersion was stirred with a homogenizer at 25 ° C. and 15,000 rpm for 15 minutes, filtered through a 200 mesh wire mesh, and the weight percentage (based on the aqueous dispersion) after drying the wire mesh product (130 ° C. × 45 minutes). evaluated.

Examples 1-4, Comparative Examples 1-3
87 parts of water is added to 10 parts of an aqueous dispersion of polyurethane urea resin, 2 parts of aminosilane (γ-aminopropyltriethoxysilane) and 1 part of a lubricant (tetraethylenepentamine distearate) to obtain a glass fiber sizing agent. It was. Table 2 shows the carboxyl group content, mechanical stability, and impact resistance improvement effect of the obtained sizing agent.

The carboxyl group content was calculated by the above formula (1) after taking out the component mainly composed of polyurethane urea resin as described above, measuring the acid value with a potentiometric titrator.
The test method for the mechanical stability of the sizing agent is the same as that for the aqueous dispersion, and the test method for the impact resistance improving effect is as follows.
<Test of impact resistance improvement effect>
A sizing agent is applied to a glass fiber having a diameter of 15 μm, 12%, and 600 glass fibers are bundled to form a strand. The strand is cut by a normal chop cutting method and dried to obtain a chopped strand having a length of 5 mm. .
30 parts of each chopped strand and 70 parts of nylon 66 resin obtained were kneaded at 270 ° C. and pelletized to obtain a test piece defined in JIS K-7062 by the injection molding method. These test pieces were subjected to an Izod impact test.
The results are shown in Table 2.

  The glass fiber obtained by using the glass fiber sizing agent of the present invention can be suitably used as a matrix fiber of a composite material such as FRP and FRTP.

Claims (5)

A glass fiber sizing agent containing an aqueous dispersion of a polyurethane urea resin (U), wherein the polyurethane urea resin (U) satisfies all of the following (1) to (3): Sizing agent.
(1): Number average of terminal isocyanate group urethane prepolymer (A) used for production of polyurethane urea resin (U) having a polyol (A1), carboxyl group or epoxy group having a number average molecular weight of 500 to 4,000. It is a terminal isocyanate group urethane prepolymer obtained by reacting a polyol (A2) having a molecular weight of 100 or more and less than 500 and a polyisocyanate (A3).
(2): Polyurethane urea resin (U) is dispersed with water and / or polyamine at the same time or after dispersing terminal isocyanate group urethane prepolymer (A) in water in the presence of emulsifier (B). This is a polyurethane urea resin obtained by stretching.
(3): The carboxyl group or epoxy group content based on the weight of the polyurethane urea resin (U) is 0.1 to 1.2% by weight.   The sizing agent for glass fibers according to claim 1, wherein the polyol (A2) is dimethylolpropionic acid, dimethylolbutanoic acid or glycerin monoglycidyl ether.   The emulsifier (B) is a water-soluble polyurethane emulsifier (B1) having an HLB of 13 to 40 and a weight average molecular weight of 5,000 to 500,000, and an HLB of 8 to less than 13 and a weight average molecular weight of 500 to 500. The sizing agent for glass fibers according to claim 1 or 2, which is an emulsifier comprising an emulsifier (B2) of 20,000. The sizing agent for glass fibers according to claim 3, wherein the water-soluble polyurethane emulsifier (B1) is a water-soluble polyurethane emulsifier (B11) represented by the following general formula (1).

[Residues except in the formula, R ¹ is the residue obtained by removing the hydroxyl of the k-valent alcohols or phenols, X is residue of an organic diisocyanate, a hydroxyl group R ² is a divalent alcohols or phenols, Z is —O (AO) mR ¹ [(OA) mOH] k-1 and / or —N (R ³ ) ₂ (wherein at least one of R ³ contains a hydrocarbon group having 1 to 100 carbon atoms or a hydroxyl group) A hydrocarbon group and the remainder is a hydrogen atom), A represents an alkylene group having 2 to 30 carbon atoms, m, n and p are each independently an integer of 0 or 1 to 150 (provided that all in {} The sum of m, n, and p is at least 10, m is not 0 when R ¹ is a phenol residue, and n and p are not 0 when R ² is a phenol residue. , a plurality of ^{m, p, R 1, X} , R 2, R 3 are not the same as or different from each other Good.), Q is an integer of 0 or 1 to 150, k is an integer of 1-6. ]   Furthermore, 1 or more types of additives chosen from the group which consists of a coupling agent, an antistatic agent, a lubricant, a heat-resistant stabilizer, a weather-resistant stabilizer, an antifoamer, and an antiseptic | preservative are contained. Any of the bundling agents for glass fibers.