JP2012021255A - Glass fiber article and glass fiber-reinforced plastic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide glass fibers which give an FRP having less white glass, excellent transparency and high strength while having an excellent bundling property which is a characteristic of a water soluble protective colloid, and to provide a glass fiber-reinforced plastic produced using the glass fibers.SOLUTION: A glass fiber article is obtained by treating glass fibers with a sizing composition including a synthetic resin emulsion obtained by polymerization of vinyl acetate monomer alone or a monomer mixture of vinyl acetate monomer and one or more unsaturated group-containing monomers copolymerizable with vinyl acetate using an alkylene-modified polyvinyl alcohol as a protective colloid.

Description

  The present invention relates to a glass fiber article suitably used to reinforce a plastic resin used for producing a glass fiber reinforced plastic, and a glass fiber reinforced plastic produced using the glass fiber article.

  Conventionally, glass fiber reinforced plastic (FRP) is excellent in strength and chemical stability, so it has been used in large quantities for a wide range of applications such as housing materials (bathtubs, septic tanks), boats, and automotive parts. . The FRP is manufactured using a resin that is a matrix such as an unsaturated polyester and a glass fiber bundle (chopped strand, hereinafter referred to as CS) cut to a certain length or a CS mat that is formed into a mat. The CS is generally bundled by a sizing agent that bundles several hundreds of glass filaments through a glass fiber spinning process and contains a polyvinyl acetate emulsion as a main component. Similarly, various compositions such as a polyvinyl acetate emulsion have been studied as a sizing agent for producing a CS mat from CS. At this time, in order to obtain FRP excellent in appearance as well as mechanical strength by utilizing the characteristics of glass fiber as a plastic reinforcing agent, this glass fiber is not damaged in the glass fiber processing step. Must be uniformly dispersed in the matrix resin and firmly bonded to the resin component, but the above sizing agent can impregnate the matrix resin between the glass fibers and the matrix resin and the glass fibers. In order to prevent adhesion, the strength and transparency of the obtained FRP are adversely affected. One indication of the compatibility or incompatibility between the glass fiber and the matrix resin is the presence of white glass. “White glass” means that white fiberglass strands can be seen when placed on a black background in a transparent FRP molded sheet. The appearance of white glass indicates that the sized glass fiber and the resin are not in contact. This contact defect generally causes a decrease in the transparency and strength of the FRP.

  When a polyvinyl acetate emulsion is used as the main component of the sizing agent, a polymer protective colloid such as polyvinyl alcohol and a polyoxyethylene oxide surfactant are conventionally used as the emulsion stabilizer. It is known that these stabilizers exert excellent binding properties to glass filaments when water-soluble protective colloids such as polyvinyl alcohol are used as an influence upon glass fiber sizing and FRP molding. However, when the above-mentioned water-soluble protective colloid is used, the sizing agent becomes insoluble in styrene which is a solvent of the unsaturated polyester which is a constituent of FRP because it is water-soluble. As a result, the unsaturated polyester resin and the glass fiber bundle The white glass cannot be penetrated to the details. Further, when a nonionic surfactant such as the above polyoxyethylene oxide surfactant is used, there is a problem that white glass is not present, but the binding property is remarkably lowered.

  Conventionally known glass fiber sizing agents used as plastic reinforcing agents are as follows.

  In U.S. Pat. No. 3,997,306, a phenolic epoxy resin, a partial ester of a polycarboxylic acid containing one or more unesterified carboxyl groups and two or more epoxy groups are used. Disclosed is a glass fiber sizing agent comprising a reaction product with a containing compound, an aminosilane coupling agent, a methacryloxyalkyltrialkoxysilane, and a nonionic surfactant.

  In US Pat. No. 4,126,729 (Patent Document 2), a glass fiber coated with a sizing composition containing an epoxidized polyvinyl acetate copolymer, a vinyl acetate ethylene copolymer and a vinyl acetate copolymer is disclosed. A chopped gun roving product is disclosed.

  U.S. Pat. No. 4,457,970 discloses treated glass fiber strands with improved processability. The treated glass fiber strand has an aqueous treatment formulation or a dry residue thereof on the glass fiber comprising the glass fiber strand. The treatment formulation may be a coupling agent, an epoxidized thermoplastic polymer or copolymer, a silane coupling agent that is organically reactive under unhydrolyzed conditions and / or partially hydrolyzed conditions, or the epoxidized polymer or The interaction product of a copolymer and an organic reactive silane coupling agent, and a fiber lubricant are included.

  U.S. Pat. No. 4,789,593 discloses a glass fiber treated with an aqueous chemical treating composition comprising a polar thermoplastic film forming polymer, a coupling agent and a lubricant. Yes. However, in all cases, the binding of CS was weak or the FRP transparency was poor.

In addition, in US Pat. No. 5,491,182 (Patent Document 5) and US Pat. No. 5,665,470 (Patent Document 6), polymers produced from various monomers, particularly an average molecular weight of 55, Disclosed is a sizing composition comprising less than 000 polymers.
In JP-A-8-291469 (Patent Document 7), a monomer composed mainly of a vinyl acetate monomer in the presence of a nonionic surfactant alone or a nonionic surfactant and a cationic surfactant is disclosed. An emulsion for glass fiber sizing agents obtained by emulsion polymerization is disclosed.
JP-T-2006-518815 (Patent Document 8) discloses a glass sizing composition containing a copolymer containing phenyl, hydroxy or alkoxylated functional groups, and has excellent compatibility with a polymeric resin material. Yes.
Although all of Patent Documents 5 to 8 refer to FRP transparency, none of them has sufficient binding properties for CS.

Furthermore, the present inventors have disclosed a glass fiber binder comprising an organic polymer emulsion and a gelling agent that gels it in Japanese Patent Application Laid-Open No. 2006-28722 (Patent Document 9). The working efficiency is not always good in terms of the mold, and the FRP transparency has not been sufficiently studied.
Japanese Patent Laid-Open No. 6-80709 (Patent Document 10) discloses a resin emulsion obtained by polymerizing a vinyl acetate monomer or the like using ethylene-modified polyvinyl alcohol and the protective colloid. However, this resin emulsion treats glass fibers and is not used for glass fiber reinforced plastics.

US Pat. No. 3,997,306 U.S. Pat. No. 4,126,729 U.S. Pat. No. 4,457,970 US Pat. No. 4,789,593 US Pat. No. 5,491,182 US Pat. No. 5,665,470 JP-A-8-291469 JP 2006-518815 A JP 2006-28722 A Japanese Patent Laid-Open No. 6-80709

  The present invention has been made in view of the above circumstances, and has an excellent bundling property which is a characteristic of a water-soluble protective colloid, while obtaining an FRP having a small amount of white glass, excellent transparency, and high strength. It is an object of the present invention to provide a glass fiber article and a glass fiber reinforced plastic produced using the glass fiber article.

  As a result of intensive studies to achieve the above object, the present inventors have found that in the presence of alkylene-modified polyvinyl alcohol, preferably modified polyvinyl alcohol containing 1 to 10 mol% of alkylene units having 4 or less carbon atoms in the molecule, acetic acid is present. Synthetic resin emulsion obtained by polymerizing vinyl monomer alone or a monomer mixture of vinyl acetate monomer and one or more unsaturated group-containing monomers copolymerizable with vinyl acetate The glass fiber treated with the sizing composition containing the glass fiber has excellent binding power, and the glass fiber reinforced plastic obtained by using the obtained glass fiber article is excellent in transparency without generating white glass. The present inventors have found that it has high strength and have come to make the present invention.

Accordingly, the present invention provides the following glass fiber article and glass fiber reinforced plastic.
Claim 1:
Monomer of vinyl acetate monomer alone or vinyl acetate monomer and one or more of unsaturated group-containing monomers copolymerizable with vinyl acetate using alkylene-modified polyvinyl alcohol as protective colloid A glass fiber article obtained by treating glass fibers with a sizing composition containing a synthetic resin emulsion obtained by polymerizing the mixture.
Claim 2:
The glass fiber article according to claim 1, wherein the alkylene-modified polyvinyl alcohol is obtained by saponifying a copolymer of vinyl ester and olefin.
Claim 3:
The glass fiber article according to claim 2, wherein the olefin is ethylene, propylene or butene.
Claim 4:
The glass fiber article according to claim 3, wherein the olefin is ethylene.
Claim 5:
Alkylene with respect to 100 parts by mass of a vinyl acetate monomer alone or a monomer mixture of a vinyl acetate monomer and one or more unsaturated group-containing monomers copolymerizable with vinyl acetate The glass fiber article according to any one of claims 1 to 4, wherein 1 to 50 parts by mass of modified polyvinyl alcohol is used.
Claim 6:
The glass fiber article according to any one of claims 1 to 5, wherein the alkylene-modified polyvinyl alcohol contains 1 to 10 mol% of an alkylene group in the molecule.
Claim 7:
The glass fiber article according to any one of claims 1 to 6, wherein the alkylene-modified polyvinyl alcohol has an average polymerization degree of 300 to 3,300 and a saponification degree of 80 mol% or more.
Claim 8:
The glass fiber article according to any one of claims 1 to 7, wherein the glass fiber article is a glass fiber bundle.
Claim 9:
The glass fiber article according to any one of claims 1 to 7, wherein the glass fiber article is a glass fiber woven or non-woven fabric.
Claim 10:
The glass fiber article according to claim 9, wherein the glass fiber nonwoven fabric is a glass fiber mat.
Claim 11:
The glass fiber article according to claim 10, wherein the glass fiber mat is a chopped strand mat or a glass wool mat.
Claim 12:
The glass fiber article according to claim 9, wherein the glass fiber woven fabric is a glass cloth.
Claim 13:
The glass fiber reinforced plastic manufactured using the glass fiber of any one of Claims 1-12.
Claim 14:
The glass fiber reinforced plastic according to claim 13, wherein the plastic is a thermosetting resin.
Claim 15:
The glass fiber reinforced plastic according to claim 14, wherein the thermosetting resin is an unsaturated polyester resin, an epoxy resin, or an epoxy novolac resin.

  According to the present invention, a glass fiber article having an excellent binding force can be obtained, and by using the glass fiber article, an FRP having little transparency of white glass, excellent transparency, and high strength can be obtained.

  The glass fiber article of the present invention comprises an unsaturated group-containing monomer that can be copolymerized with a vinyl acetate monomer alone or a vinyl acetate monomer and vinyl acetate using an alkylene-modified polyvinyl alcohol as a protective colloid. And a glass fiber sizing composition containing a synthetic resin emulsion obtained by polymerizing a monomer mixture with one or more of these (hereinafter collectively referred to as ethylenically unsaturated group-containing monomers). It will be.

Below, a glass fiber sizing composition is demonstrated in detail.
The alkylene-modified polyvinyl alcohol (hereinafter, modified PVA) used in the present invention can be obtained by saponifying a copolymer of a vinyl ester and an olefin such as ethylene, propylene, or butene. Examples of vinyl esters include vinyl formate, vinyl acetate, vinyl propionate, vinyl pivalate, etc., but vinyl acetate is economically preferable.

  In the modified PVA, the content of alkylene units in the molecule is preferably 1 to 10 mol%, more preferably 5 to 10 mol%. If the alkylene unit content is less than 1 mol%, sufficient transparency of FRP may not be obtained, and if it exceeds 10 mol%, polymerization may not be possible. The alkylene unit is preferably an ethylene unit having 4 or less carbon atoms, particularly 2 carbon atoms.

  The modified PVA may be one obtained by copolymerizing an ethylenically unsaturated monomer that can be copolymerized within a range that does not impair the effects of the present invention. Examples of such ethylenically unsaturated monomers include acrylic acid, methacrylic acid, (anhydrous) phthalic acid, (anhydrous) maleic acid, (anhydrous) itaconic acid, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, Trimethyl- (3-acrylamido-3-dimethylpropyl) -ammonium chloride, acrylamido-2-methylpropanesulfonic acid and its sodium salt, ethyl vinyl ether, butyl vinyl ether, N-vinyl pyrrolidone, vinyl chloride, vinyl bromide, vinyl fluoride , Vinylidene chloride, vinylidene fluoride, tetrafluoroethylene, sodium vinyl sulfonate, sodium allyl sulfonate and the like. In addition, vinyl ester monomers such as vinyl acetate are copolymerized with ethylene monomers having 4 or less carbon atoms in the presence of thiol compounds such as thiol acetic acid and mercaptopropionic acid, and saponified. It is also possible to use a terminal modified product obtained by

The saponification degree of the modified PVA used in the present invention is preferably 80 mol% or more, and more preferably 95 mol% or more, although it depends on the ethylene monomer content. Moreover, 300-3,300 are preferable, as for the average degree of polymerization of this modified PVA, 300-2,000 are more preferable, and 300-1,000 are still more preferable.
In addition, the said average degree of polymerization can be calculated | required as a number average value of polystyrene conversion in GPC (gel permeation chromatography) analysis (hereinafter the same).

  1-50 mass parts is preferable with respect to 100 mass parts of ethylenically unsaturated group containing monomers mentioned later, and, as for the usage-amount of modified PVA, 5-30 mass parts is still more preferable. If the amount of the modified PVA used is less than 1 part by mass, the stability during emulsion polymerization may decrease, and if it exceeds 50 parts by mass, sufficient FRP transparency may not be obtained.

  The ethylenically unsaturated group-containing monomer used in the present invention is a vinyl acetate monomer alone or a vinyl acetate monomer and one or two types of unsaturated group-containing monomers copolymerizable with vinyl acetate. It is a monomer mixture with the above. Examples of the unsaturated group-containing monomer copolymerizable with vinyl acetate include a carboxyl group-containing ethylenically unsaturated monomer and an alkoxycarbonyl group-containing ethylenically unsaturated monomer.

Here, examples of the carboxyl group-containing ethylenically unsaturated monomer include ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, itaconic acid, maleic acid, and fumaric acid. Acid and methacrylic acid.
As the alkoxy group of the alkoxycarbonyl group-containing ethylenically unsaturated monomer, those having 1 to 10 carbon atoms, particularly 1 to 4 carbon atoms are preferable, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. Examples of the alkoxycarbonyl group-containing ethylenically unsaturated monomer include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, etc. Preferably, ethyl acrylate and butyl acrylate are used.

  When the ethylenically unsaturated group-containing monomer is used as a monomer mixture, the mixing ratio thereof is such that the vinyl acetate monomer can be copolymerized with vinyl acetate with respect to 50 to 99.9% by mass. It is preferable that a saturated group containing monomer is 0.1-50 mass%. If the unsaturated group-containing monomer copolymerizable with vinyl acetate exceeds 50% by mass, FRP transparency may be lowered.

  Moreover, the ethylenically unsaturated group containing monomer which has a functional group can also be mixed in the range which does not impair the effect of this invention. Examples thereof include epoxy group-containing monomers such as glycidyl methacrylate, methylol group-containing monomers such as N-methylol acrylamide, alcoholic hydroxyl group-containing monomers such as 2-hydroxyethyl methacrylate, methoxy Alkoxy group-containing monomers such as ethyl acrylate, nitrile group-containing monomers such as acrylonitrile, amide group-containing monomers such as acrylamide, amino group-containing monomers such as dimethylaminoethyl methacrylate, divinylbenzene And monomers having two or more ethylenically unsaturated groups in one molecule such as allyl methacrylate.

  When the ethylenically unsaturated group-containing monomer having a functional group is mixed, the blending amount of the monomer is 10% by mass or less, preferably 5% by mass, based on the total amount of the ethylenically unsaturated group-containing monomer. It is as follows.

  For the polymerization of the ethylenically unsaturated group-containing monomer, any known emulsion polymerization method can be employed. Modified PVA, ethylenically unsaturated group-containing monomer and other polymerization aids (for example, emulsifiers such as alkyl sulfate ester salts, polymerization initiators such as ammonium persulfate, chain transfer agents such as mercaptans, pH of sodium carbonate, etc. A regulator, various antifoaming agents, etc.) may be added all at once in the initial stage, or may be added continuously, or a part thereof may be added continuously or divided during the polymerization.

  In the emulsion polymerization, it is also possible to use the following surfactants (1) to (5) and water-soluble polymers as long as the effects of the present invention are not impaired.

(1) Anionic surfactants such as alkyl sulfates, polyoxyethylene alkyl ether sulfates, alkylbenzene sulfonates, alkyl diphenyl ether disulfonates, alkyl naphthalene sulfonates, fatty acid salts, dialkyl sulfosuccinates, alkyls Surfactants such as phosphate ester salts and polyoxyethylene alkylphenyl phosphate ester salts.

(2) Nonionic surfactants such as polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyalkylene alkyl ethers, polyoxyethylene derivatives , Surfactants such as glycerin fatty acid ester, polyoxyethylene hydrogenated castor oil, polyoxyethylene alkylamine, alkylalkanolamide, or acetylene alcohol, acetylene glycol and ethylene oxide adducts thereof.

(3) Cationic surfactants such as alkyltrimethylammonium chloride, dialkyldimethylammonium chloride, alkylbenzylammonium chloride, alkylamine salts and the like.

(4) Polymerizable surfactants having a double bond having radical polymerization ability in the molecule, such as alkylallylsulfosuccinate, methacryloyl polyoxyalkylene sulfate, polyoxyethylene nonylpropenyl phenyl ether sulfate, etc. Polymerizable surfactant.

(5) Water-soluble polymers such as polyvinyl alcohol other than modified PVA, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, starch and other water-soluble fiber derivatives, polyacrylic acid and salts thereof, polymethacrylic acid and salts thereof, Polymers such as synthetic polymer electrolytes such as partially saponified products of polyacrylamide and polyacrylate.

  When the surfactant and the water-soluble polymer are used, the addition amount is preferably 0.1 to 20% by mass, more preferably 0.1% by mass relative to the ethylenically unsaturated group-containing monomer. 5 to 10% by mass.

Examples of the polymerization initiator used in the emulsion polymerization include persulfates such as ammonium persulfate and potassium persulfate, azo compounds such as 2,2′-diamidino-2,2′-azopropane dihydrochloride, azobisisobutyronitrile and the like. , Peroxides such as cumene hydroperoxide, benzoyl peroxide, and hydrogen peroxide. In addition, known redox initiators such as potassium persulfate and sodium bisulfite, hydrogen peroxide and tartaric acid, and the like can also be mentioned.
The usage-amount of a polymerization initiator is 0.05-5 mass% normally with respect to the said monomer, Preferably it is 0.1-2 mass%.

  The polymerization temperature for carrying out the emulsion polymerization is usually 10 to 90 ° C, desirably 50 to 80 ° C. The polymerization time is 3 to 20 hours. This polymerization is desirably performed in an atmosphere of an inert gas such as nitrogen gas.

The solid content in the synthetic resin emulsion obtained by the above polymerization is preferably 25 to 50% by mass, particularly preferably 30 to 40% by mass.
The viscosity of the synthetic resin emulsion obtained by the above polymerization may be appropriately adjusted depending on the type of fiber, but is 50 to 1,500 mPa · s (25 ° C.), particularly 100 to 1,000 mPa · s (25 ° C.). It is preferable that The viscosity can be measured with a rotational viscometer (hereinafter the same).

  In addition to the synthetic resin emulsion obtained above, the glass fiber sizing composition used in the present invention may contain, as necessary, a cellulose-based water-soluble polymer such as hydroxymethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, Saponified polyvinyl alcohol, partially saponified polyvinyl alcohol, polyacrylic acid and its salts, polymethacrylic acid and its salts, polyacrylamide, synthetic water-soluble polymers such as alkali-thickened acrylic emulsion, ammonia, triethylamine, sodium hydroxide, etc. Bases, polyethylene waxes, antifoaming agents, leveling agents, tackifiers, antiseptics, antibacterial agents, rust inhibitors, surface treatment agents, lubricants, antistatic agents, etc., within a range that does not impair the purpose of the present invention. Can be blended.

Next, the glass fiber article will be described.
The glass fiber article of the present invention is obtained by treating glass fiber with the glass fiber sizing composition obtained as described above, and as the glass fiber article obtained by treating with the glass fiber sizing composition, Articles made of non-woven fabric or woven fabric made of glass fiber, specifically, articles made of non-woven fabric include glass fiber bundles (CS), a mat made of glass fiber mat such as CS mat or glass wool, etc. Examples of the article made of woven fabric include glass cloth.

  The glass fiber sizing composition of the present invention is particularly suitable for the production of glass fiber woven fabrics and nonwoven fabrics, specifically mats, particularly glass fiber mats such as CS mats and glass wool mats.

  In the case of glass fiber woven fabrics and nonwoven fabrics such as CS mats, glass filaments are spun from a number of nozzles attached to the bottom of the glass melting furnace, and a sizing agent based on a vinyl acetate resin emulsion is applied immediately afterwards. After being bundled into a strand, it is wound up to form a cake. Next, the cake is dried, and a plurality of strands are drawn therefrom and cut into a predetermined length (this is CS). Thereafter, these cut products are evenly deposited on a moving net conveyor, and the glass fiber sizing composition of the present invention is applied and dried to prepare a CS mat having a predetermined density.

  When applying the glass fiber sizing composition, a known coating machine such as a spray, curtain coater, gravure roll coater, reverse roll coater or the like can be used. Moreover, when apply | coating, the glass fiber sizing composition of this invention may be used as it is, and it may dilute and use suitably with water etc. The glass fiber sizing composition is usually used after being diluted so that the solid content is 1 to 10% by mass. The diluting solvent is preferably ion-exchanged water that is environmentally friendly.

The coating amount of the glass fiber sizing composition is usually 0.5 to 20% by mass, preferably 1 to 10% by mass in terms of solid content with respect to the strand cut product (glass fiber deposit). When the coating amount is less than 0.5% by mass, the bonding force between the glass fibers of the glass fiber woven fabric / non-woven fabric may be insufficient, and when it exceeds 20% by mass, the thermosetting resin at the time of FRP preparation The impregnation property may be reduced.
As for the drying conditions after coating, it is desirable to dry at a temperature of 100 to 180 ° C.

The glass fiber sizing composition of the present invention can also be used as a sizing agent for bundling the above CS glass filaments.
In this case, a glass fiber sizing composition containing a surface treatment agent, a lubricant, an antistatic agent and the like can be suitably used. The compounding amounts of the surface treating agent, lubricant, and antistatic agent are each preferably 0.01 to 1% by mass in the glass fiber sizing composition.
When used as a sizing agent for CS, the application method and application amount of the glass fiber sizing composition are the same as the application method and application amount of the glass fiber sizing composition at the time of preparing the CS mat described above. It is desirable that the drying conditions after the application are dried at a temperature of 100 to 180 ° C.

Furthermore, the glass fiber sizing composition of the present invention can also be used as a sealing agent for fabrics such as glass cloth.
In this case, the glass cloth is dipped in a sizing agent diluted solution in which the solid content of the glass fiber sizing composition is adjusted to 1 to 10% by mass and dried at 100 to 180 ° C.

In the present invention, a glass fiber reinforced plastic (FRP) can be produced by impregnating the above-mentioned CS mat with a thermosetting resin and curing the thermosetting resin. Here, examples of the thermosetting resin include unsaturated polyester resins, epoxy resins, and epoxy novolac resins.
As a method for applying the thermosetting resin, a method in which the cut CS mat is placed on a flat panel and the thermosetting resin is poured onto the CS mat can be employed. The amount of the thermosetting resin used at this time is 10 to 50% by mass, preferably 20 to 40% by mass, based on the total mass of the FRP. It can obtain by making it harden | cure on 10-100 degreeC and 10 minutes-10 hours after application | coating.

  Hereinafter, the present invention will be described in detail by way of examples. In addition, the part and% in an Example show a mass part and mass%.

[Example 1]
(Emulsion production)
A 3 L glass container equipped with a stirrer, a reflux condenser, and a thermometer was prepared. In this glass container, 173 parts of ion-exchanged water, ethylene-modified PVA (A) (ethylene content 7%, saponification degree 98.5) %, Average degree of polymerization 400) 20 parts were added, and after sufficient air replacement with nitrogen, stirring was started.
The internal temperature of the glass container was raised to 80 ° C., and 100 parts of vinyl acetate monomer, 1 part of 10% hydrogen peroxide solution and 1.5 parts of 10% tartaric acid aqueous solution were continuously added for 4 hours each. Then, it was made to react at 80 degreeC for 1 hour, and it cooled to 30 degreeC.
A vinyl acetate polymer emulsion having an evaporation residue (solid content) of 35.0% and a viscosity of 100 mPa · s was obtained. In addition, the measuring method of evaporation residue and a viscosity is as showing below.

Ｒ：蒸発残分（％）
Ｗ：乾燥前の試料を入れたアルミニウム箔皿の質量（ｇ）
Ｌ：アルミニウム箔皿の質量（ｇ）
Ｔ：乾燥後の試料を入れたアルミニウム箔皿の質量（ｇ）
アルミニウム箔皿の寸法：７０φ×１２ｈ（ｍｍ） <Evaporation residue>
About 1 g of a sample is accurately weighed in an aluminum foil dish, placed in a drier kept at about 105 ° C., heated for 1 hour, then removed from the drier and allowed to cool in a desiccator. The weight was measured and the evaporation residue (solid content) was calculated by the following formula.

R: evaporation residue (%)
W: Mass (g) of the aluminum foil pan containing the sample before drying
L: Mass of aluminum foil pan (g)
T: Mass (g) of the aluminum foil dish containing the dried sample
Aluminum foil pan dimensions: 70φ x 12h (mm)

<Viscosity>
The sample liquid temperature was kept at 25 ± 1.0 ° C. and measured with a BH viscometer (20 rpm).

(Production of CS mat)
A chopped strand UPDE13ZA509 (glass fiber thickness: 6 μm, glass fiber length: 13 mm) manufactured by Unitika Glass Fiber Co., Ltd. is dropped and deposited on a moving conveyor to form a mat-like material with a basis weight of 450 g / m ² From above, the polymer emulsion diluted with ion-exchanged water so as to have a solid content of 4% was spray-coated. The amount of polymer attached to the mat-like material was set to 4% of the amount of the mat-like material. Subsequently, it was dried in a drying furnace at 150 ° C. for 10 minutes to obtain a CS mat.
The tensile strength of the obtained CS mat was measured by the following method. The results are shown in Table 1.

<Tensile strength>
The CS mat obtained above was cut into a size of 150 mm in length and 50 mm in width to obtain a sample for measuring tensile strength. Using a Tensilon type tensile tester, the longitudinal strength of the sample was measured at a tensile rate of 5 mm / min.

(FRP production)
The CS mat obtained above is cut into a size of 150 mm in length and 50 mm in width and placed on a flat panel, and 100 parts of Rigolac 158BQT-2 (made by Showa Polymer Co., Ltd., unsaturated polyester) and Parmec N A mixture of 1 part (manufactured by NOF Corporation, methyl ethyl ketone peroxide) was poured onto the CS mat, homogenized with a roller for application, and cured at 25 ° C. for 60 minutes to obtain FRP.
The obtained FRP was obtained by using 28% of a thermosetting resin with respect to the total mass of the FRP. The characteristics of this FRP were evaluated by the following methods. The results are shown in Table 1.

<Transparency>
The presence of the FRP white glass obtained above was visually confirmed and evaluated according to the following criteria.
○: Glass fiber is visible ×: Glass fiber is not visible

<Accelerated test>
As FRP characteristics, the FRP obtained above was subjected to a boiling acceleration test in warm water at 90 ° C. for 500 hours, the appearance after the test was visually confirmed, and evaluated according to the following criteria.
○: No occurrence of cracks or deterioration of the resin is observed ×: Generation of cracks along the glass fiber is observed

[Examples 2 to 9, Comparative Examples 1 to 4]
Emulsion polymerization was performed in the same manner as in Example 1 with the composition shown in Table 1 to obtain various emulsions. Then, CS mats and FRPs were prepared in the same manner as in Example 1, and their performance was evaluated.

Modified PVA (A): ethylene content 7%, saponification degree 98.5%, average polymerization degree 400
Modified PVA (B): ethylene content 5%, saponification degree 98.5%, average polymerization degree 400
Modified PVA (C): ethylene content 9%, saponification degree 98.5%, average polymerization degree 400
Modified PVA (D): ethylene content 7%, saponification degree 95.0%, average polymerization degree 300
PVA (E): ethylene content 0%, saponification degree 80.0%, average polymerization degree 300
PVA (F): ethylene content 0%, saponification degree 98.5%, average polymerization degree 500
Emulgen 1135S-70: manufactured by Kao Corporation, polyoxyethylene alkyl ether

Claims (15)

  Monomer of vinyl acetate monomer alone or vinyl acetate monomer and one or more of unsaturated group-containing monomers copolymerizable with vinyl acetate using alkylene-modified polyvinyl alcohol as protective colloid A glass fiber article obtained by treating glass fibers with a sizing composition containing a synthetic resin emulsion obtained by polymerizing the mixture.   The glass fiber article according to claim 1, wherein the alkylene-modified polyvinyl alcohol is obtained by saponifying a copolymer of vinyl ester and olefin.   The glass fiber article according to claim 2, wherein the olefin is ethylene, propylene or butene.   The glass fiber article according to claim 3, wherein the olefin is ethylene.   Alkylene with respect to 100 parts by mass of a vinyl acetate monomer alone or a monomer mixture of a vinyl acetate monomer and one or more unsaturated group-containing monomers copolymerizable with vinyl acetate The glass fiber article according to any one of claims 1 to 4, wherein 1 to 50 parts by mass of modified polyvinyl alcohol is used.   The glass fiber article according to any one of claims 1 to 5, wherein the alkylene-modified polyvinyl alcohol contains 1 to 10 mol% of an alkylene group in the molecule.   The glass fiber article according to any one of claims 1 to 6, wherein the alkylene-modified polyvinyl alcohol has an average polymerization degree of 300 to 3,300 and a saponification degree of 80 mol% or more.   The glass fiber article according to any one of claims 1 to 7, wherein the glass fiber article is a glass fiber bundle.   The glass fiber article according to any one of claims 1 to 7, wherein the glass fiber article is a glass fiber woven or non-woven fabric.   The glass fiber article according to claim 9, wherein the glass fiber nonwoven fabric is a glass fiber mat.   The glass fiber article according to claim 10, wherein the glass fiber mat is a chopped strand mat or a glass wool mat.   The glass fiber article according to claim 9, wherein the glass fiber woven fabric is a glass cloth.   The glass fiber reinforced plastic manufactured using the glass fiber of any one of Claims 1-12.   The glass fiber reinforced plastic according to claim 13, wherein the plastic is a thermosetting resin.   The glass fiber reinforced plastic according to claim 14, wherein the thermosetting resin is an unsaturated polyester resin, an epoxy resin, or an epoxy novolac resin.