Glass fiber sizing agent and glass chopped strands

Abstract

To provide a glass fiber sizing agent which can achieve both good water dispersibility and reduction in fuzz when formed into a glass chopped strand, and a glass chopped strand.SOLUTION: A glass fiber sizing agent contains (A) a polyacrylamide-based resin, (B) a polyvinyl alcohol-based resin, and (C) aminosilane. A glass chopped strand has a film containing (A) a polyacrylamide-based resin, (B) a polyvinyl alcohol-based resin and (C) aminosilane formed thereon.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a glass fiber sizing agent and glass chopped strands. [Background technology]

[0002] Conventionally, glass chopped strands have been known. The glass chopped strands are glass strands cut to a predetermined length. The glass chopped strands are processed into glass paper or the like by a wet papermaking method, for example, and are used for various purposes.

[0003] Glass chopped strands are generally produced as follows: Molten glass, obtained by melting glass raw materials, is drawn out from a bushing as hundreds to thousands of single fibers (filaments), a sizing agent is applied to the drawn filaments to bundle them into glass strands, and the glass strands are wound around a cylindrical bobbin to form a cake. The glass strands are then drawn out from the cake and cut to a predetermined length with a cutting blade to form glass chopped strands.

[0004] A glass fiber sizing agent containing a urethane resin, an amino resin, and a silane coupling agent as essential components is known as a glass fiber sizing agent for use in glass chopped strands (see, for example, Patent Document 1). When this glass fiber sizing agent is used as a surface treatment agent for glass fibers and as a reinforcing material for a matrix resin, it is said that by strengthening the bond at the interface between the glass fibers and the matrix resin, it is possible to increase the static and dynamic mechanical strength of the glass fiber reinforced resin.

[0005] In addition, glass fibers, (a) a water-soluble, dispersible, or emulsifiable polyoxyethylene polymer having a molecular weight effective to form a film; (b) an effective amount of a white water miscible polymeric agent capable of reacting with the water soluble, dispersible or emulsifiable aldehyde condensate; (c) an organosilane coupling agent reactive with an aldehyde condensate, which is capable of exhibiting an interaction in which the aldehyde condensate-reactive polymeric agent and the silane coupling agent bond with each other and with the resinous material of the aldehyde condensate in the presence of the resinous material; (d) cationic lubricants and (e) a carrier in an amount effective to apply the aqueous chemical treatment composition to the glass fibers; Glass fibers treated with a chemical treatment composition comprising the following are known (see, for example, Patent Document 2). The glass fibers are chopped glass fibers that can be quickly dispersed in an aqueous solution, and are said to have good processability and can be produced into glass fiber-containing paper with good strength. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-56503 [Patent Document 2] Japanese Patent Application Publication No. 62-87439 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the glass chopped strands obtained by applying the sizing agents disclosed in Patent Documents 1 and 2 to glass fibers have the problem that they are unable to sufficiently achieve both good water dispersibility during wet papermaking and reduced fluff.

[0008] Therefore, a main object of the present invention is to solve the above problems and to provide a glass fiber sizing agent that can achieve both good water dispersibility and reduced fuzz when made into glass chopped strands, and glass chopped strands. [Means for solving the problem]

[0009] The present inventors have investigated the above problem and found that fuzz occurs in the glass strand manufacturing process (hereinafter, sometimes referred to as the "spinning process") before the glass chopped strands are produced. One possible way to reduce the generation of fuzz in the spinning process is to improve the bundling ability of the glass strands. However, simply improving the bundling ability of the glass strands tends to result in poor dispersibility of the numerous filaments that make up the glass chopped strands when the glass chopped strands are wet-laid for papermaking. In other words, there is a trade-off between reducing the generation of fuzz in the glass strands and improving the water dispersibility of the glass chopped strands.

[0010] The present inventors have conducted extensive research to solve the above problems and have found that the above problems can be solved by using a glass fiber sizing agent containing (A) a polyacrylamide resin, (B) a polyvinyl alcohol resin, and (C) an aminosilane. The present invention was completed based on these findings and further research.

[0011] That is, the present invention provides the following aspects. Item 1. A glass fiber sizing agent comprising (A) a polyacrylamide resin, (B) a polyvinyl alcohol resin, and (C) an aminosilane. Item 2. The glass fiber sizing agent according to Item 1, further comprising (D) a polyoxyethylene alkylamide or a polyoxyethylene alkylamine salt. Item 3. The glass fiber sizing agent according to Item 1 or 2, wherein the ratio of the non-volatile components of the polyvinyl alcohol resin (B) to the non-volatile components of the polyacrylamide resin (A) (non-volatile components of polyvinyl alcohol resin / non-volatile components of polyacrylamide resin) is 0.2 to 0.5. Item 4. Glass chopped strands comprising glass fibers having a coating formed on the surface thereof, the coating containing (A) a polyacrylamide resin, (B) a polyvinyl alcohol resin, and (C) an aminosilane. Item 5. The glass chopped strands according to Item 4, wherein the coating further contains (D) a polyoxyethylene alkylamide or a polyoxyethylene alkylamine salt. Item 6. The glass chopped strands according to Item 4 or 5, wherein the ratio of the non-volatile components of the (B) polyvinyl alcohol-based resin to the non-volatile components of the (A) polyacrylamide-based resin (non-volatile components of polyvinyl alcohol-based resin / non-volatile components of polyacrylamide-based resin) is 0.2 to 0.5. [Effects of the Invention]

[0012] The glass fiber sizing agent of the present invention contains (A) a polyacrylamide resin, (B) a polyvinyl alcohol resin, and (C) an aminosilane, and therefore can achieve both good water dispersibility and reduced fuzz when formed into glass chopped strands. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a photograph illustrating the state of glass chopped strands according to the five-point evaluation criteria in a test of water dispersibility in an example. [Figure 2] 1 is a photograph illustrating the state of glass chopped strands according to four evaluation criteria in a test of water dispersibility in an example. [Figure 3] 1 shows photographs illustrating the state of three points among the evaluation criteria of the test for water dispersibility of glass chopped strands in the examples. [Figure 4] 1 is a photograph illustrating the state of two of the evaluation criteria for the test of water dispersibility of glass chopped strands in an example. [Figure 5] 1 is a photograph illustrating the state of glass chopped strands according to one of the evaluation criteria for the test of water dispersibility in the examples. DETAILED DESCRIPTION OF THE INVENTION

[0014] 1.Glass fiber sizing agent The glass fiber sizing agent of the present invention contains (A) a polyacrylamide resin, (B) a polyvinyl alcohol resin, and (C) an aminosilane. The glass fiber sizing agent of the present invention will be described in detail below.

[0015] (A) Polyacrylamide resin The glass fiber sizing agent of the present invention contains a polyacrylamide resin. By including the polyacrylamide resin and the aminosilane described below, the polyacrylamide resin and the aminosilane can be combined to provide excellent water dispersibility when formed into glass chopped strands.

[0016] In the present invention, the polyacrylamide resin refers to a polymer containing polymerization units based on acrylamide or its derivatives, and includes polyacrylamide copolymers obtained by copolymerizing acrylamide with a monomer copolymerizable therewith, modified products of such polyacrylamide copolymers, and modified products of acrylamide homopolymers. Of these, acrylamide-vinyl acetate copolymer resins are preferred from the viewpoint of achieving both water dispersibility and suppression of fuzz generation when formed into glass chopped strands.

[0017] The proportion of the non-volatile components of component (A) relative to 100 parts by mass of the total mass of all non-volatile components contained in the glass fiber sizing agent of the present invention is, for example, 3 to 40 parts by mass, and preferably 5 to 30 parts by mass. In the present invention, the "non-volatile components" refer to the bone-dry components obtained by removing the solvent and the like through heat treatment at 110°C under normal pressure and reaching a constant weight.

[0018] In the glass fiber sizing agent of the present invention, the ratio of the non-volatile components of the polyvinyl alcohol resin (B) described below to the non-volatile components of the polyacrylamide resin (A) (non-volatile components of polyvinyl alcohol resin / non-volatile components of polyacrylamide resin) is, for example, 0.2 to 5, and from the viewpoint of achieving both good water dispersibility and reduced fuzz when formed into glass chopped strands, a ratio of 0.2 to 0.5 is preferred.

[0019] The concentration of component (A) in the glass fiber sizing agent of the present invention is, for example, 0.01 to 0.5 mass %, preferably 0.1 to 0.5 mass %.

[0020] (B) Polyvinyl alcohol resin The glass fiber sizing agent of the present invention contains a polyvinyl alcohol-based resin, which makes it possible to suppress the generation of fluff without impairing the water dispersibility of the glass chopped strands achieved by component (A) and the component (C) described below.

[0021] In the present invention, polyvinyl alcohol resins are saponified polymers of vinyl ester monomers such as vinyl acetate, and may be copolymerized with other vinyl monomers as long as water solubility is not impaired. However, those represented by the following general formula (1) (CAS number 25213-24-5) are preferred.

[0022] [ka]

[0023] The average degree of polymerization of the polyvinyl alcohol resin is, for example, 300 to 2000, preferably 300 to 1000. The average degree of polymerization is measured in accordance with JIS K 6726:1994.

[0024] The saponification degree of the polyvinyl alcohol resin is, for example, 85 mol% or more and 100 mol% or less, preferably 85 mol% or more and 90 mol% or less. In this specification, the saponification degree of the polyvinyl alcohol resin is measured in accordance with JIS K 6726:1994.

[0025] The proportion of the nonvolatile components of component (B) relative to 100 parts by mass of the total mass of all nonvolatile components contained in the glass fiber sizing agent of the present invention is, for example, 3 to 30 parts by mass, and preferably 5 to 10 parts by mass.

[0026] The concentration of component (B) in the glass fiber sizing agent of the present invention is, for example, 0.01 to 0.5% by mass, preferably 0.05 to 0.2% by mass.

[0027] (C) Aminosilane The glass fiber sizing agent of the present invention contains an aminosilane. The inclusion of the aforementioned polyacrylamide resin and aminosilane in combination can provide excellent water dispersibility when formed into glass chopped strands. Furthermore, the aminosilane can improve the impregnation of the glass chopped strands with a matrix resin when the glass chopped strands are used as a fiber material in a fiber-reinforced resin.

[0028] Aminosilane refers to a compound having a group containing a silicon atom to which a hydrolyzable group is bonded and a substituted or unsubstituted amino group. Examples of the substituent of the substituted amino group include an alkyl group and an aryl group. The alkyl group may be, for example, an alkyl group having 1 to 5 carbon atoms or an alkyl group having 1 to 3 carbon atoms. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group. The aryl group may be, for example, an aryl group having 6 to 12 carbon atoms or an aryl group having 6 to 10 carbon atoms. Specific examples of the aryl group include a substituted or unsubstituted phenyl group and a substituted or unsubstituted naphthyl group. Examples of the substituent of the aryl group include an alkyl group having 1 to 5 carbon atoms. Specific examples of the alkyl group are the same as those described above. The amino group may be a primary amino group, a secondary amino group, or a tertiary amino group. Examples of hydrolyzable groups bonded to silicon atoms include alkoxy groups having 1 to 5 carbon atoms, acyloxy groups having 1 to 5 carbon atoms, and alkenyloxy groups having 1 to 5 carbon atoms. Among these, alkoxy groups are preferred from the viewpoints of versatility and hydrolysis. Examples of alkoxy groups include methoxy and ethoxy groups. The number of hydrolyzable groups bonded to silicon atoms in the aminosilane is preferably 1 to 3, more preferably 2 or 3, and even more preferably 3.

[0029] The aminosilane is not particularly limited, and examples thereof include N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine and its partial hydrolyzates, 3-trimethoxysilyl-N-(1,3-dimethylbutylidene)propylamine and its partial hydrolyzates, and N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride. These may be used alone or in combination of two or more. Among these, 3-aminopropyltriethoxysilane is preferred from the viewpoint of achieving both good water dispersibility and reduced fluff when formed into glass chopped strands.

[0030] The proportion of the nonvolatile components of component (C) relative to 100 parts by mass of the total mass of all nonvolatile components contained in the glass fiber sizing agent of the present invention is, for example, 3 to 40 parts by mass, and preferably 5 to 10 parts by mass.

[0031] The concentration of component (C) in the glass fiber sizing agent of the present invention is, for example, 0.01 to 0.5% by mass, preferably 0.05 to 0.4% by mass.

[0032] (D) Polyoxyethylene alkylamide or polyoxyethylene alkylamine salt The glass fiber sizing agent of the present invention can contain (D) a polyoxyethylene alkylamide or a polyoxyethylene alkylamine salt in addition to the components (A) to (C). By containing these, the foaming property of the sizing agent can be further suppressed while the generation of fluff can be further suppressed, and the application of the sizing agent to the glass strands can be more reliably achieved.

[0033] The proportion of the nonvolatile components of component (D) relative to 100 parts by mass of the total mass of all nonvolatile components contained in the glass fiber sizing agent of the present invention is, for example, 20 to 50 parts by mass, and preferably 35 to 45 parts by mass.

[0034] The concentration of component (D) in the glass fiber sizing agent of the present invention is, for example, 0.1 to 0.9 mass %, preferably 0.2 to 0.7 mass %.

[0035] Other non-volatile components other than (A) to (D)

[0036] In addition to components (A) to (D), the glass fiber sizing agent of the present invention may contain other non-volatile components within the range in which the effects of the present invention are exhibited.

[0037] The glass fiber of the present invention may contain, as the other non-volatile component, a reaction product obtained by reacting a fatty acid with an amine compound represented by the following general formula (2), or an alkylamide derivative represented by the following general formula (3). By containing these, the glass strand can be endowed with even greater flexibility, and the generation of fluff during cutting of the glass strand to produce glass chopped strands can be further suppressed.

[0038] [ka]

[0039] In the above general formula (2), R 1 represents an alkylene group having 1 to 10 carbon atoms, and n represents an integer of 0 to 10. Specific examples of the amine compound represented by general formula (2) include diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, and hexaethyleneheptamine. In the present invention, R 1is more preferably an alkylene group having 2 to 10 carbon atoms, even more preferably an alkylene group having 2 to 6 carbon atoms, and particularly preferably an ethylene group. n is more preferably 1 to 8, even more preferably 1 to 6, and particularly preferably 3. Therefore, tetraethylenepentamine is preferred as the amine compound. On the other hand, examples of fatty acids to be reacted with the amine compound include saturated or unsaturated fatty acids, and in the present invention, it is preferred to use saturated fatty acids having 6 to 32 carbon atoms. As fatty acids, saturated fatty acids having 12 to 30 carbon atoms are more preferred, saturated fatty acids having 12 to 22 carbon atoms are even more preferred, and stearic acid is particularly preferred.

[0040] [ka]

[0041] In general formula (3), R 1 represents a linear or branched alkyl or alkenyl group. 1 The number of carbon atoms in the alkyl group or alkenyl group is, for example, 7 to 23, preferably 10 to 18, and more preferably 12 to 16. In addition, in the general formula (3), R 2 represents a methyl group, an ethyl group, a hydroxymethyl group, or a hydroxyethyl group.

[0042] The proportion of non-volatile components of the reaction product obtained by reacting a fatty acid with an amine compound represented by the general formula (2) above and the alkylamide derivative represented by the general formula (3) above relative to the total mass of all non-volatile components contained in the glass fiber sizing agent of the present invention (100 parts by mass) is, for example, 10 to 25 parts by mass, preferably 10 to 20 parts by mass.

[0043] In addition, in the glass fiber sizing agent of the present invention, the concentration of the reaction product obtained by reacting a fatty acid with the amine compound represented by the general formula (2) above and the alkylamide derivative represented by the general formula (3) above is, for example, 0.05 to 0.4 mass %, preferably 0.1 to 0.35 mass %.

[0044] The glass fiber sizing agent of the present invention may contain lubricants, emulsifiers, softeners, antistatic agents, preservatives, antifoaming agents, etc. as other non-volatile components other than the reaction product of the reaction of the fatty acid with the amine compound represented by general formula (2) and the alkylamide derivative represented by general formula (3). The proportion of the other non-volatile components other than the reaction product of the reaction of the fatty acid with the amine compound represented by general formula (2) and the alkylamide derivative represented by general formula (3) relative to 100 parts by mass of all non-volatile components contained in the glass fiber sizing agent of the present invention may be, for example, 1 part by mass or less. The concentration of the other components other than the reaction product of the reaction of the fatty acid with the amine compound represented by general formula (2) and the alkylamide derivative represented by general formula (3) in the glass fiber sizing agent of the present invention may be, for example, 0.01% by mass or less.

[0045] In the glass fiber sizing agent of the present invention, the total concentration of non-volatile components (total concentration of components (A) to (D) and other non-volatile components) is, for example, 0.3 to 3 mass%, preferably 1 to 2 mass%.

[0046] Aqueous solvent (volatile components) The glass fiber sizing agent of the present invention contains an aqueous solvent (volatile component) as a base. The type of aqueous medium is not particularly limited, but examples include water, water-soluble organic solvents, and mixtures thereof. Examples of water-soluble organic solvents include alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, ethyl carbitol, ethyl cellosolve, and butyl cellosolve, and polar solvents such as N-methylpyrrolidone. The concentration of the aqueous solvent in the glass fiber sizing agent of the present invention may be any concentration as long as it accounts for the remainder excluding non-volatile components.

[0047] Manufacturing method of glass fiber sizing agent The glass fiber sizing agent of the present invention can be obtained by mixing predetermined amounts of components (A) to (C), other nonvolatile components that are blended as needed, and an aqueous solvent.

[0048] 2. Glass chopped strands The glass chopped strands of the present invention comprise glass fibers having a coating formed on the surface thereof, the coating containing (A) a polyacrylamide resin, (B) a polyvinyl alcohol resin, and (C) an aminosilane.

[0049] The type of glass fiber constituting the glass chopped strands to be treated with the glass fiber sizing agent of the present invention is not particularly limited, but examples include E glass, T glass, S glass, D glass, NE glass, C glass, H glass, ARG glass, and quartz glass.

[0050] The average fiber diameter of the glass fibers constituting the glass chopped strands of the present invention is not particularly limited, but is preferably 3 to 9 μm, more preferably 5 to 7 μm, from the viewpoint of achieving both good water dispersibility and reduced fuzz when the glass chopped strands are formed. In the present invention, the average fiber diameter is measured by embedding the glass chopped strands in an epoxy resin (product name: 3091, manufactured by Marumoto Struers Co., Ltd.) and curing it, polishing it to an extent that the cross section of the glass fibers can be observed, and observing and measuring it at a magnification of 500 times using an SEM (product name: JSM-6390A, manufactured by JEOL Ltd.). Twenty glass chopped strands are randomly selected, and the diameters (largest parts) of all the glass fibers (single fibers) of the 20 glass chopped strands are measured, and the average value is calculated, which is the average fiber diameter of the glass chopped strands.

[0051] The number of glass fibers constituting the glass chopped strand of the present invention is not particularly limited, but may be, for example, 100 to 1000, and preferably 400 to 800.

[0052] The length of the glass chopped strands of the present invention is not particularly limited, but may be, for example, 1 to 30 mm, and from the viewpoint of water dispersibility, preferably 2 to 15 mm. The length of the glass chopped strands is measured in accordance with JIS R 3420:2013 7.8.

[0053] The ignition loss of the glass chopped strand of the present invention is, for example, 0.05 to 0.4 mass%, and from the viewpoint of achieving both good water dispersibility and reduced fuzz when formed into glass chopped strands, is preferably 0.15 to 0.4 mass%. In the present invention, the ignition loss of the glass chopped strand is measured in accordance with JIS R 3420:2013 7.3.2.

[0054] The moisture content of the glass chopped strands of the present invention is, for example, 1 to 15% by mass, and from the viewpoint of achieving both good water dispersibility and reduced fuzz when the glass chopped strands are formed, is preferably 5 to 10% by mass. In the present invention, the moisture content of the glass chopped strands is measured in accordance with JIS R 3420:2013 7.3.1.

[0055] Manufacturing method of glass chopped strands The method for producing the glass chopped strands of the present invention may include a glass strand preparation step of applying the glass fiber sizing agent of the present invention described above to glass fibers to prepare glass strands having a coating containing (A) a polyacrylamide resin, (B) a polyvinyl alcohol resin, and (C) an aminosilane formed on the surface of the glass fibers, and a cutting step of cutting the prepared glass strands to obtain chopped strands.

[0056] In the above-mentioned glass strand preparation step, the glass fiber sizing agent of the present invention can be applied to the glass fibers using, for example, a belt-type or roller-type applicator, a spray, or the like. Furthermore, a known bundling machine can be used to bundle the glass fibers coated with the glass fiber sizing agent of the present invention. Furthermore, drying after bundling can be carried out, for example, at a temperature in the range of room temperature to 150°C. Thus, by applying the glass fiber sizing agent of the present invention to the glass fibers, bundling them, and then drying, volatile components such as the aqueous solvent are removed, and a glass strand can be obtained in which a film of nonvolatile components contained in the glass fiber sizing agent of the present invention is formed on the surface of the glass fibers.

[0057] In the cutting step, the glass strands can be cut by any known method, such as by using various types of rotary cutters.

[0058] Applications of glass chopped strands The glass chopped strands of the present invention can be used for, for example, glass paper, glass chopped strand mats, glass nonwoven fabrics, etc. [Example]

[0059] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0060] 1.Measurement method etc. (1) Ignition loss and moisture content (mass%) of glass chopped strands Measurement was carried out by the method described above.

[0061] (2) Average fiber diameter of glass chopped strands (μm) Measurement was carried out by the method described above.

[0062] (3) Water dispersibility of glass chopped strands 10 g of glass chopped strands were collected and placed in a beaker containing 2 L of pure water. The mixture was stirred at 450 rpm for 5 minutes using a stirrer, and the stirrer was then stopped. The dispersion state of the glass chopped strands was visually confirmed. The results were evaluated according to the following criteria. A score of 3 or higher was deemed to be excellent in water dispersibility and was considered to be acceptable. 5 points: The glass chopped strands are finely separated and a considerable amount of glass fibers have settled in the beaker (see Figure 1). 4 points: The glass chopped strands are open and the glass fibers have settled (see Figure 2). 3 points: The glass chopped strands are somewhat open and the glass fibers have settled to a certain extent (see Figure 3). 2 points: The glass chopped strands were not opened much and remained in a bulky pile (see Figure 4). 1 point: The glass chopped strands were barely opened and piled up in a bulky pile (see Figure 5).

[0063] (4) Number of fluffs (pieces / km) The glass strand before being made into glass chopped strand was unwound from the cake at a speed of 100 m / min, and the number of fluffs after passing through a tension bar was counted with a sensor. The number of fluffs per km (pieces / km) was calculated by counting over 10 km. A value of 20 pieces / km or less was considered acceptable.

[0064] (5) Foaming evaluation 10 g of glass chopped strands were collected and placed in a beaker containing 2 L of pure water. The mixture was stirred at 450 rpm for 5 minutes using a stirrer. The stirrer was then stopped, and the time until the bubbles that had formed on the surface of the beaker disappeared was measured by visual observation. The mixture was then evaluated according to the following criteria. A score of 3 or higher was deemed to be excellent in foamability and pass the test. 5 points: within 10 seconds 4 points: 11~20 seconds 3 points: 21~30 seconds 2 points: 31~40 seconds 1 point: 41 seconds or more

[0065] 2. Materials used to prepare glass fiber sizing agent In the examples and comparative examples, the following components were used as blending components in the glass fiber sizing agent. (1) Polyacrylamide resin (Marposol A-200, manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd.), non-volatile components: 15% by mass, acrylamide-vinyl acetate copolymer resin (2) Polyvinyl alcohol resin (Nippon Synthetic Chemical Industry Co., Ltd., trade name: Gohsenol GL-05), non-volatile content: 95% by mass, average polymerization degree: 500, average saponification degree: 88% (3) Aminosilane (product name KBE903 manufactured by Shin-Etsu Chemical Co., Ltd.), non-volatile components: 100% by mass, 3-aminopropyltriethoxysilane (4) Glycidoxypropyltrimethoxysilane (SH-6040, manufactured by Dow Toray Industries, Inc.), non-volatile content 100% by mass (5) Polyoxyethylene alkylamide (trade name: Esomaide HT-15, manufactured by Lion Specialty Chemicals Co., Ltd.), non-volatile components 100% by mass (6) Polyoxyethylene alkylamine salt (manufactured by Matsumoto Oil & Fat Co., Ltd., trade name: Sondes KV), non-volatile component: 20% by mass (7) A reaction product of a fatty acid and an amine compound represented by general formula (2) (trade name: Sofnon GW-18, manufactured by Toho Chemical Industry Co., Ltd.), non-volatile components: 30% by mass, condensation product of tetraethylenepentamine and stearic acid (8) Alkylamide derivatives, non-volatile components: 30% by mass (9) Antifoaming agent (product name: Silicon TSA-730, manufactured by Momentive Performance Materials Japan, LLC), non-volatile components: 40% by mass

[0066] 3. Manufacturing of glass chopped strands Example 1 (1) Manufacturing of glass fiber sizing agents A glass fiber sizing agent was obtained by mixing with a predetermined amount of water as an aqueous solvent so that the nonvolatile component composition ratio would be as shown in Table 1. The concentration of nonvolatile components in the glass fiber sizing agent was 0.61% by mass.

[0067] (2) Glass strand manufacturing process The glass fiber sizing agent was applied to a plurality of long glass fibers (E glass, average fiber diameter 6 μm, number of glass fibers 800) spun out of a spinning furnace using an applicator, and the glass fibers were bundled into a single bundle (strand). This strand was then wound around a tube without twisting to obtain a cake. The resulting cake was then dried.

[0068] (3) Cutting process Glass strands were pulled out of the cake and cut into chopped strands.

[0069] <Example 2> (1) Manufacturing of glass fiber sizing agents A glass fiber sizing agent was obtained by mixing with a predetermined amount of water as an aqueous solvent so that the nonvolatile component composition ratio would be as shown in Table 1. The concentration of nonvolatile components in the glass fiber sizing agent was 0.71% by mass.

[0070] (2) Glass strand manufacturing process The glass fiber sizing agent was applied to a plurality of long glass fibers (E glass, average fiber diameter 6 μm, number of glass fibers 800) spun out of a spinning furnace using an applicator, and the glass fibers were bundled into a single bundle (strand). This strand was then wound around a tube without twisting to obtain a cake. The resulting cake was then dried.

[0071] (3) Cutting process Glass strands were pulled out of the cake and cut into chopped strands.

[0072] Example 3 (1) Manufacturing of glass fiber sizing agents A glass fiber sizing agent was obtained by mixing with a predetermined amount of water as an aqueous solvent so that the nonvolatile component composition ratio would be as shown in Table 1. The concentration of nonvolatile components in the glass fiber sizing agent was 0.81% by mass.

[0073] (2) Glass strand manufacturing process The glass fiber sizing agent was applied to a plurality of long glass fibers (E glass, average fiber diameter 6 μm, number of glass fibers 800) spun out of a spinning furnace using an applicator, and the glass fibers were bundled into a single bundle (strand). This strand was then wound around a tube without twisting to obtain a cake. The resulting cake was then dried.

[0074] (3) Cutting process Glass strands were pulled out of the cake and cut into chopped strands.

[0075] Example 4 (1) Manufacturing of glass fiber sizing agents A glass fiber sizing agent was obtained by mixing with a predetermined amount of water as an aqueous solvent so that the nonvolatile component composition ratio would be as shown in Table 1. The concentration of nonvolatile components in the glass fiber sizing agent was 1.21% by mass.

[0076] (2) Glass strand manufacturing process The glass fiber sizing agent was applied to a plurality of long glass fibers (E glass, average fiber diameter 6 μm, number of glass fibers 800) spun out of a spinning furnace using an applicator, and the glass fibers were bundled into a single bundle (strand). This strand was then wound around a tube without twisting to obtain a cake. The resulting cake was then dried.

[0077] (3) Cutting process Glass strands were pulled out of the cake and cut into chopped strands.

[0078] <Example 5> (1) Manufacturing of glass fiber sizing agents A glass fiber sizing agent was obtained by mixing with a predetermined amount of water as an aqueous solvent so that the nonvolatile component composition ratio would be as shown in Table 1. The concentration of nonvolatile components in the glass fiber sizing agent was 1.82 mass%.

[0079] (2) Glass strand manufacturing process The glass fiber sizing agent was applied to a plurality of long glass fibers (E glass, average fiber diameter 6 μm, number of glass fibers 800) spun out of a spinning furnace using an applicator, and the glass fibers were bundled into a single bundle (strand). This strand was then wound around a tube without twisting to obtain a cake. The resulting cake was then dried.

[0080] (3) Cutting process Glass strands were pulled out of the cake and cut into chopped strands.

[0081] Example 6 (1) Manufacturing of glass fiber sizing agents A glass fiber sizing agent was obtained by mixing with a predetermined amount of water as an aqueous solvent so that the nonvolatile component composition ratio would be as shown in Table 1. The concentration of nonvolatile components in the glass fiber sizing agent was 1.80 mass%.

[0082] (2) Glass strand manufacturing process The glass fiber sizing agent was applied to a plurality of long glass fibers (E glass, average fiber diameter 6 μm, number of glass fibers 800) spun out of a spinning furnace using an applicator, and the glass fibers were bundled into a single bundle (strand). This strand was then wound around a tube without twisting to obtain a cake. The resulting cake was then dried.

[0083] (3) Cutting process Glass strands were pulled out of the cake and cut into chopped strands.

[0084] Example 7 (1) Manufacturing of glass fiber sizing agents A glass fiber sizing agent was obtained by mixing with a predetermined amount of water as an aqueous solvent so that the nonvolatile component composition ratio would be as shown in Table 1. The concentration of nonvolatile components in the glass fiber sizing agent was 1.84 mass%.

[0085] (2) Glass strand manufacturing process The glass fiber sizing agent was applied to a plurality of long glass fibers (E glass, average fiber diameter 6 μm, number of glass fibers 800) spun out of a spinning furnace using an applicator, and the glass fibers were bundled into a single bundle (strand). This strand was then wound around a tube without twisting to obtain a cake. The resulting cake was then dried.

[0086] (3) Cutting process Glass strands were pulled out of the cake and cut into chopped strands.

[0087] Example 8 (1) Manufacturing of glass fiber sizing agents A glass fiber sizing agent was obtained by mixing with a predetermined amount of water as an aqueous solvent so that the nonvolatile component composition ratio would be as shown in Table 1. The concentration of nonvolatile components in the glass fiber sizing agent was 0.56 mass%.

[0088] (2) Glass strand manufacturing process The glass fiber sizing agent was applied to a plurality of long glass fibers (E glass, average fiber diameter 6 μm, number of glass fibers 800) spun out of a spinning furnace using an applicator, and the glass fibers were bundled into a single bundle (strand). This strand was then wound around a tube without twisting to obtain a cake. The resulting cake was then dried.

[0089] (3) Cutting process Glass strands were pulled out of the cake and cut into chopped strands.

[0090] <Comparative Example 1> (1) Manufacturing of glass fiber sizing agents A glass fiber sizing agent was obtained by mixing with a predetermined amount of water as an aqueous solvent so that the nonvolatile component composition ratio would be as shown in Table 1. The concentration of nonvolatile components in the glass fiber sizing agent was 0.61% by mass.

[0091] (2) Glass strand manufacturing process The glass fiber sizing agent was applied to a plurality of long glass fibers (E glass, average fiber diameter 6 μm, number of glass fibers 800) spun out of a spinning furnace using an applicator, and the glass fibers were bundled into a single bundle (strand). This strand was then wound around a tube without twisting to obtain a cake. The resulting cake was then dried.

[0092] (3) Cutting process Glass strands were pulled out of the cake and cut into chopped strands.

[0093] <Comparative Example 2> (1) Manufacturing of glass fiber sizing agents A glass fiber sizing agent was obtained by mixing with a predetermined amount of water as an aqueous solvent so that the nonvolatile component composition ratio would be as shown in Table 1. The concentration of nonvolatile components in the glass fiber sizing agent was 1.83 mass%.

[0094] (2) Glass strand manufacturing process The glass fiber sizing agent was applied to a plurality of long glass fibers (E glass, average fiber diameter 6 μm, number of glass fibers 800) spun out of a spinning furnace using an applicator, and the glass fibers were bundled into a single bundle (strand). This strand was then wound around a tube without twisting to obtain a cake. The resulting cake was then dried.

[0095] (3) Cutting process Glass strands were pulled out of the cake and cut into chopped strands.

[0096] <Comparative Example 3> (1) Manufacturing of glass fiber sizing agents A glass fiber sizing agent was obtained by mixing with a predetermined amount of water as an aqueous solvent so that the nonvolatile component composition ratio would be as shown in Table 1. The concentration of nonvolatile components in the glass fiber sizing agent was 1.80 mass%.

[0097] (2) Glass strand manufacturing process The glass fiber sizing agent was applied to a plurality of long glass fibers (E glass, average fiber diameter 6 μm, number of glass fibers 800) spun out of a spinning furnace using an applicator, and the glass fibers were bundled into a single bundle (strand). This strand was then wound around a tube without twisting to obtain a cake. The resulting cake was then dried.

[0098] (3) Cutting process Glass strands were pulled out of the cake and cut into chopped strands.

[0099] 4. Evaluation results of glass chopped strands The physical properties of the glass chopped strands obtained in Examples 1 to 8 and Comparative Examples 1 to 3 were measured, and the results are shown in Table 1.

[0100] [Table 1]

[0101] In Examples 1 to 8, the glass fiber sizing agent contained (A) a polyacrylamide resin, (B) a polyvinyl alcohol resin, and (C) an aminosilane, and therefore it was possible to achieve both good water dispersibility and reduced fuzz when formed into glass chopped strands.

[0102] Comparing Examples 1, 4, and 5, Examples 4 and 5 had a total concentration of non-volatile components in the glass fiber sizing agent of 1 to 2 mass%, and the ignition loss of the obtained glass chopped strands was 0.15 to 0.3 mass%, so they had better water dispersibility than Example 1 and achieved a better balance between good water dispersibility and reduced fuzz.

[0103] Comparing Examples 5, 6, and 7, Example 5 had a ratio of the non-volatile components of the (B) polyvinyl alcohol resin to the non-volatile components of the (A) polyacrylamide resin (non-volatile components of polyvinyl alcohol resin / non-volatile components of polyacrylamide resin) of 0.2 to 0.5, and therefore had a better balance of good water dispersibility and reduced fuzz when made into glass chopped strands than Examples 6 and 7.

[0104] On the other hand, in Comparative Example 1, the glass fiber sizing agent did not contain (C) aminosilane, and therefore it was not possible to achieve water dispersibility and reduction in fluff when made into glass chopped strands.

[0105] In Comparative Example 2, the glass fiber sizing agent did not contain the polyvinyl alcohol resin (B), and therefore fluff reduction could not be achieved.

[0106] In Comparative Example 3, the glass fiber sizing agent did not contain (A) polyacrylamide resin, and therefore the water dispersibility of the glass chopped strands was poor.

Claims

1. A glass fiber sizing agent comprising (A) a polyacrylamide resin, (B) a polyvinyl alcohol resin, (C) an aminosilane, and (D) a polyoxyethylene alkylamide, The (C) aminosilane is at least one selected from the group consisting of N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine and partial hydrolysates thereof, 3-trimethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine and partial hydrolysates thereof, and N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride.

2. 2. The glass fiber sizing agent according to claim 1, wherein the ratio of the non-volatile components of the polyvinyl alcohol-based resin (B) to the non-volatile components of the polyacrylamide-based resin (A) (non-volatile components of polyvinyl alcohol-based resin / non-volatile components of polyacrylamide-based resin) is 0.2 to 0.

5.

3. A glass fiber sizing agent as described in claim 1 or 2, wherein the ratio of the non-volatile components of (D) polyoxyethylene alkylamide to the total mass of all non-volatile components contained in the glass fiber sizing agent (100 parts by mass) is 31 to 50 parts by mass.

4. A glass fiber bundling agent described in any one of claims 1 to 3, wherein the ratio of the non-volatile components of the (A) polyacrylamide-based resin to the total mass of all non-volatile components contained in the glass fiber bundling agent (100 parts by mass) is 21.2 to 40 parts by mass.

5. A glass fiber sizing agent according to any one of claims 1 to 4 (excluding those containing polyoxyethylene polymers).

6. A glass chopped strand comprising glass fibers having a coating formed on a surface thereof, the coating containing (A) a polyacrylamide resin, (B) a polyvinyl alcohol resin, (C) an aminosilane, and (D) a polyoxyethylene alkylamide, The (C) aminosilane is at least one selected from the group consisting of N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine and partial hydrolysates thereof, 3-trimethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine and partial hydrolysates thereof, and N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride.

7. 7. The glass chopped strands according to claim 6, wherein the ratio of the non-volatile components of the polyvinyl alcohol-based resin (B) to the non-volatile components of the polyacrylamide-based resin (A) (non-volatile components of polyvinyl alcohol-based resin / non-volatile components of polyacrylamide-based resin) is 0.2 to 0.

5.

8. The glass chopped strands according to claim 7, having a loss on ignition of 0.15 to 0.4 mass%.

9. Glass chopped strands according to any one of claims 6 to 8, wherein the ratio of the non-volatile components of (D) polyoxyethylene alkylamide to the total mass of all non-volatile components of the coating (100 parts by mass) is 31 to 50 parts by mass.

10. Glass chopped strands according to any one of claims 6 to 9, wherein the ratio of the non-volatile components of the (A) polyacrylamide resin to the total mass of all non-volatile components of the coating (100 parts by mass) is 21.2 to 40 parts by mass.

11. A glass chopped strand according to any one of claims 6 to 10 (excluding those in which the coating contains a polyoxyethylene polymer).

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