JP2016216859A - Aqueous size agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous size agent having no need for a heat cleaning treatment when using the aqueous size agent containing starch, solving the problem of reduced heat resistance when using the aqueous size agent containing a silane coupling agent and capable of achieving stable and excellent weaving performance and weaving openability.SOLUTION: There is provided an aqueous size agent containing 100 pts.mass of (A) polyoxyalkylene bisphenol A ether, 3 to 20 pts.mass of (B) one or more compound selected from polyoxyalkylene alkyl ester, quaternary ammonium salt and inorganic salt, 100 to 200 pts.mass of (C) polyoxyalkylene glycol and 5 to 50 pts.mass of (D) one or more compound selected from benzotriazol, benzophenone, triazine, hindered phenol, benzoate and hindered amine and containing no starch or silica coupling agent.SELECTED DRAWING: None

Description

  The present invention relates to an aqueous sizing agent for imparting bundling and weaving properties to a fiber, a glass fiber surface-treated with the aqueous sizing agent, a glass fiber cloth woven using the glass fiber, and the glass fiber. The present invention relates to a prepreg using a cloth and a composite material.

  In recent years, with the reduction in weight of electronic devices, there is an increasing demand for thinning glass fiber cloth that is a reinforcing material for printed circuit boards. As an effort to reduce the thickness of glass fiber cloth, we are proceeding with high-density weaving by applying glass fibers with fine counts (single fiber diameter of 5 μm or less). The woven glass fiber cloth is subjected to a fiber-opening process and processed to be thinner than immediately after weaving. By processing the substrate thinner, it is possible to improve the impregnation property of the matrix resin when producing the printed circuit board, and to improve the processing speed of the printed circuit board.

  In order to improve the weaving property, the glass fiber is woven after attaching an aqueous sizing agent containing starch. Glass fiber cloth woven using starch-sized glass fibers is subjected to a heat cleaning process to remove starch in order to prevent adverse effects on mechanical properties, heat resistance, electrical properties, etc. as a substrate material. . Further, the glass fiber cloth is subjected to a surface treatment in order to enhance the adhesiveness of the matrix resin.

  However, in the heat cleaning process, the glass fiber cloth is exposed to a high temperature of 400 ° C. or higher for a long time, so that the glass fiber deteriorates due to heat and the strength thereof decreases. Further, in the surface treatment, the glass fiber cloth is washed by a high-pressure water-washing jet, so that the glass fiber damaged by the heat cleaning process is damaged and fluff is generated. In particular, in a cloth woven with fine count glass fibers and subjected to a heat cleaning process, the influence of these processing steps is large.

  Thus, studies have been made on aqueous sizing agents containing resins that do not require heat cleaning. For example, Patent Document 1 proposes to use an aqueous sizing agent containing an epoxy resin, bisphenol A ether to which ethylene oxide is added, and a silane coupling agent.

  However, since the aqueous sizing agent described in Patent Document 1 contains a silane coupling agent, hydrolysis and condensation progress with the passage of time, and the state of the liquid changes. Therefore, the silane monomer couple | bonded with the glass fiber surface reduces, and ensuring of heat resistance becomes difficult for the glass fiber sized with the sizing agent which time passed. Furthermore, since glass fiber treated with an aqueous sizing agent containing a silane coupling agent is not heat-treated, unreacted siloxane oligomers remain on the glass fiber surface, leading to deterioration of weaving properties and heat resistance. It will be.

JP 2007-162171 A

  The present invention solves the above-mentioned problems, does not require a heat cleaning process when an aqueous sizing agent containing starch is used, and lowers the storage stability of a liquid when an aqueous sizing agent containing a silane coupling agent is used. An object of the present invention is to provide a water-based sizing agent capable of eliminating the problem and realizing stable and excellent weaving properties and heat resistance.

  As a result of intensive studies, the present inventors have found that an aqueous sizing agent having a specific composition excluding starch and a silane coupling agent can solve the above problems, and have reached the present invention. That is, the gist of the present invention is as follows.

(1) 100 parts by mass of polyoxyalkylene bisphenol A ether (A), 3 to 20 parts by mass of one or more compounds (B) selected from polyoxyalkylene alkyl esters, quaternary ammonium salts and inorganic salts, and polyoxy Contains 100 to 200 parts by weight of alkylene glycol (C) and 5 to 50 parts by weight of one or more compounds (D) selected from benzotriazole, benzophenone, triazine, hindered phenol, benzoate and hindered amine, and starch and silane cup An aqueous sizing agent characterized by not containing a ring agent.
(2) The aqueous sizing agent according to (1), wherein the hydroxyl value of (A) is 200 mgOH / g or less.
(3) A glass fiber having a surface treated with the aqueous sizing agent according to (1) or (2).
(4) A glass fiber cloth woven using the glass fiber according to (3).
(5) A prepreg comprising the glass fiber cloth according to (4).
(6) A composite material using the glass fiber cloth according to (4).

  According to the present invention, there is no need for a heat cleaning process when an aqueous sizing agent containing starch is used, and the short pot life when using an aqueous sizing agent containing a silane coupling agent is eliminated, which is stable and excellent. An aqueous sizing agent that achieves weaving and storage stability can be provided. In addition, the glass fiber cloth woven using the glass fiber surface-treated with the aqueous sizing agent of the present invention is excellent in heat resistance and mechanical properties, so that it is used as a reinforcing material for printed circuit boards used in electrical equipment and the like. Can be preferably used.

Hereinafter, the present invention will be described in detail.
The aqueous sizing agent of the present invention comprises polyoxyalkylene bisphenol A ether (A), one or more compounds (B) selected from polyoxyalkylene alkyl esters, quaternary ammonium salts and inorganic salts, polyoxyalkylene glycol ( C) and one or more compounds (D) selected from benzotriazole, benzophenone, triazine, hindered phenol, benzoate and hindered amine, and no starch and silane coupling agent. The term “not contained” as used herein means that it is not substantially contained, and may be contained in a trace amount as long as the effects of the present invention are not impaired.

  The aqueous sizing agent of the present invention needs to contain polyoxyalkylene bisphenol A ether (A). (A) is used for the purpose of covering the surface of glass fiber, reducing friction generated during weaving and aging, and suppressing the occurrence of fluff and yarn breakage. (A) is a polyoxyethylene bisphenol A ether because it has high film-forming properties and is highly effective in imparting fuzz, antistatic properties and lubricity, and is particularly excellent in antistatic properties and suppression of fuzz. preferable.

  (A) preferably has a hydroxyl value of 200 mgKOH / g or less. When the hydroxyl value exceeds 200 mgKOH / g, the amount of (A) attached to the glass fiber may decrease, and the glass fiber has a high frictional force with each member, and fluff and thread breakage may occur. is there.

  The aqueous sizing agent of the present invention needs to contain one or more compounds (B) selected from polyoxyalkylene alkyl esters, quaternary ammonium salts and inorganic salts. (B) is used for the purpose of reducing the chargeability of the fiber.

  Examples of the polyoxyalkylene alkyl ester include polyoxyethylene alkyl ester, and examples of the quaternary ammonium salt include lauryl trimethyl ammonium chloride, lauryl dimethyl benzyl ammonium chloride, lauryl dimethyl ethyl ammonium ethyl sulfate, stearyl trimethyl ammonium. Chloride, stearyldimethylhydroxyethylammonium paratoluenesulfonate, cetyltrimethylammonium chloride, distearyldimethylammonium chloride, alkylbenzyldimethylammonium chloride, octyldimethylethylammonium ethylsulfate, palmityldimethylethylammonium ethylsulfate, didecyldimethylammonium Chloride, include tributyl benzyl ammonium chloride, the inorganic salts, such as ammonium salts, lithium salts, include magnesium salts, specifically, ammonium chloride, ammonium sulfate, lithium chloride, magnesium chloride. (B) may be used individually by 1 type among the above, and may use multiple types together.

  The content of (B) is required to be 3 to 20 parts by mass with respect to 100 parts by mass of (A), and preferably 5 to 10 parts by mass. When the content of (B) is less than 3 parts by mass, it becomes difficult to prevent charging, the unraveling property of the yarn during weaving is lowered, and the weaving property is lowered. On the other hand, when the content of (B) exceeds 20 parts by mass, the unwinding property from the feeder on the weaving machine is lowered, and the weaving property is lowered.

  The aqueous size of the present invention needs to contain polyoxyalkylene glycol (C). (C) is used for the purpose of adhering more (A) to the glass fiber surface. Examples of (C) include polyethylene glycol and polypropylene glycol, and polyethylene glycol is preferable from the viewpoint of improving electrostatic characteristics.

  Content of (C) needs to be 100-200 mass parts with respect to 100 mass parts of (A), and it is preferable that it is 130-160 mass parts. When the content of (C) is less than 100 parts by mass, (A) is less likely to be coated on the glass fiber surface, and the unwinding tension is increased, causing fluff generation. On the other hand, if it exceeds 200 parts by mass, more (C) adheres to the glass fiber surface than (A), so that the frictional force increases and the weaving property decreases.

  The aqueous sizing agent of the present invention needs to contain one or more compounds (D) selected from benzotriazole, benzophenone, triazine, hindered phenol, benzoate and hindered amine. (D) is used for the purpose of reducing the friction with a member that forms minute irregularities on the surface of the glass fiber and contacts the glass fiber, and improves the weaving property and warping. (D) is preferably a hindered amine. By using a hindered amine, the winding state of the feeder part on the weaving machine is stabilized and the weaving property is improved. Moreover, since hindered amine is excellent in compatibility with the matrix resin, it exhibits excellent mechanical properties when used as a reinforcing material for printed circuit boards.

  Content of (D) needs to be 5-50 mass parts with respect to 100 mass parts of (A), and it is preferable that it is 15-40 mass parts. When the content of (D) is less than 5 parts by mass, the effect of reducing friction between the yarn and the contact guide is small, and the weaving property is deteriorated. On the other hand, when it exceeds 50 mass parts, the winding in the feeder part of a weaving machine will become unstable and weaving property will fall.

  The aqueous sizing agent of the present invention is used by adhering to the surface of fibers such as inorganic fibers, natural fibers, and synthetic fibers. Examples of the inorganic fiber include glass, carbon, graphite, mullite, and aluminum oxide. Examples of natural fibers include cotton, cellulose, natural rubber, flax, hemp, ramie, sisal, and wool. Examples of synthetic fibers include fibers containing thermoplastic resins, such as polyamide, polylactic acid, polyarylate, liquid crystal polymer, polyester, acrylic resin, polycarbonate, polyurethane, polyvinyl resin, and fibers containing polyolefin resin. Can be mentioned.

  The fiber whose surface is coated with the water-based sizing agent of the present invention is excellent in flexibility, low friction property and low chargeability, and has excellent weaving properties because generation of fluff is suppressed.

  The aqueous sizing agent of the present invention may further contain fine particles for the purpose of improving the spreadability. Examples of the fine particles include polymer fine particles and inorganic fine particles.

  Examples of the polymer constituting the polymer fine particles include polylactic acid, polyarylate, liquid crystal polymer, polycarbonate, polyphenylene sulfide, polyamide, dimer acid polyamide, polytetrafluoroethylene, polyvinyl chloride, polyester, polyethyleneimine, polyoxymethylene, poly Examples include ether ether ketone, polyurethane, polyvinyl resin, polyolefin resin, polyacrylate, and polyurethane acrylate. Among these fine particles made of a polymer, polyurethane polyacrylate fine particles are preferable because they have a high effect of improving the openability.

  Examples of the inorganic substance constituting the inorganic fine particles include silicon carbide, aluminum nitride, silica, clay, boron nitride, graphite, metal dichalcogenide, cadmium iodide, silver sulfide, for example, indium, thallium, tin, copper, and zinc. , Metal inorganic materials containing one or more metals selected from gold and silver. Among these, boron nitride is preferable because it has a high effect of improving the spreadability. The fine particles may be used alone or in combination of two or more of the above.

  The water-based sizing agent of the present invention may further contain a water-soluble resin other than an epoxy resin for the purpose of improving fiber convergence and suppressing the generation of fluff. Examples of water-soluble resins include acrylic resins, methacrylic resins, polyvinyl alcohol resins, polyvinyl pyrrolidone resins, and acryloyl morpholine resins. One of the above water-soluble resins may be used alone, or a plurality of water-soluble resins may be used in combination.

  The aqueous sizing agent of the present invention further comprises a pH adjuster, a curing agent, a curing catalyst, a functional filler, an antistatic aid, a softening agent, a thickener, a leveling agent, an antioxidant, a flame retardant, a flame retardant aid, A heat stabilizer or the like may be included. Examples of the pH adjuster include acetic acid. Examples of the curing agent include aliphatic polyamines, alicyclic polyamines, amine-epoxy addition products, polyamide polyamines, aromatic polyamines, glycidyl ethers, and glycidyl esters. Examples of the curing catalyst include tris (dimethylaminomethyl) phenol and trisethylhexylate. Examples of the functional filler include a heat conductive filler, an electromagnetic wave shielding particle filler, a heat insulating filler, and a high dielectric filler.

  The total solid content concentration of (A), (B), (C) and (D) in the aqueous sizing agent of the present invention is preferably 2 to 10% by mass. If the aqueous sizing agent has a solid content concentration of less than 2% by mass, it is difficult to uniformly coat the fibers, and the fibers are likely to fluff, and the heat resistance and mechanical properties may decrease. On the other hand, when the solid content concentration exceeds 10% by mass, the amount of solid content attached to the fiber increases, and the weaving property may be deteriorated due to stickiness of the fiber surface and adhesion of excessive fine particles.

  The aqueous sizing agent of the present invention can be produced by dispersing (A), (B), (C) and (D) in water. More specifically, (B) is first mixed with water and stirred. Thereafter, (A), (C) and (D) are further added and stirred. In addition, (A), (B), and (C) may be added to and mixed with water containing (D), respectively, and (A), (B), (C), and (D) may be mixed. The mixture may be added to water and mixed.

  When adding an inorganic filler to the mixture of (A), (B), (C) and (C), the mixture and the inorganic filler may be mixed using a stirring blade, a bead mill, a three roll mill, and a jet mill. . Only when solid materials such as inorganic substances are not mixed with the above mixture, they may be mixed using a disper or vibration stirring. When using a disper, the number of rotations is preferably 500 to 3000 rpm, when using vibration stirring, the frequency is preferably 30 to 50 Hz, and when using a bead mill, it is preferable to use a chiller. By setting the number of rotations and the number of vibrations within the above ranges, or using a chiller, an aqueous sizing agent can be obtained while effectively suppressing heat generation due to heat of stirring.

  The glass fiber whose surface is treated with the aqueous sizing agent of the present invention can be obtained by applying the aqueous sizing agent to the glass fiber by a known method (for example, roller sizing method, roller dipping method, spray method). it can. From the viewpoint of weaving properties and heat resistance, the amount of the aqueous sizing agent (solid content) attached to the glass fiber is 100 parts by mass in total of the glass fiber and the aqueous sizing agent (solid content) attached to the glass fiber. 0.10 to 0.30 parts by mass, and more preferably 0.15 to 0.25 parts by mass.

  The prepreg of the present invention can be obtained by impregnating a glass fiber cloth with a matrix resin and curing it. As a specific method, for example, a glass fiber cloth is opened by applying water pressure or air pressure of 0.1 to 2.0 MPa, and further impregnated with a matrix resin such as an epoxy resin, and 0.05 to 0.05 at 50 to 150 ° C. A semi-cured prepreg can be obtained by taking ~ 2 hours. Examples of the method of impregnating the matrix resin include a method of immersing glass fiber cloth in a resin solution.

  A semi-cured prepreg is further cured at 150 to 200 ° C. for 0.5 to 4 hours, whereby a composite material suitable for a reinforcing material for a printed circuit board can be obtained. The composite material of the present invention has high interfacial adhesion between glass fiber and matrix resin, is excellent in heat resistance, and is not affected by soldering heat even in a hygroscopic state.

  The aqueous sizing agent of the present invention does not contain starch and a silane coupling agent unlike conventional aqueous sizing agents. For this reason, by using the aqueous sizing agent of the present invention, fluctuations in yarn quality and deterioration in weaving properties when not used for a long time are suppressed. Moreover, the heat cleaning process becomes unnecessary, and the deterioration of the glass fiber that has conventionally occurred in these processes is suppressed. The suppression effect is particularly noticeable when the number of glass fibers bundled is reduced and the fiber diameter of the glass fibers is reduced as the electronic equipment is reduced in size and thickness.

  The glass fiber, the glass fiber cloth, the prepreg and the composite material of the present invention can be suitably used as a reinforcing material for a printed circuit board, and parts of computers such as a smartphone, a tablet, a power device, a personal computer, and a home game machine; Parts for DVD players, DVD recorder parts, HDD recorder parts, display power supply units for home televisions, plasma displays, liquid crystal televisions, etc .; parts for mobile phones, various AV equipment, OA equipment, etc .; car stereos, car navigation systems , Inverters, lighting, automotive electrical components, automotive engine members, automotive brake members, automotive interior members, aerospace materials, sports applications, outdoor applications, and general industrial materials.

  Examples of the present invention will be specifically described below, but the present invention is not limited to these examples.

A method for measuring and evaluating the characteristics of the aqueous sizing agent, glass fiber, glass fiber cloth, and cured composite material is as follows.
(1) Amount of water-based sizing agent attached to glass fiber In accordance with JIS R 3420, the ignition loss was measured as follows.
The glass fiber to which the aqueous sizing agent was adhered was dried with hot air at 110 ° C. for 1 hour, moisture (water derived from the aqueous sizing agent) was removed from the glass fiber, and the weight W ₁ of the glass fiber after removing the water was measured. Next, the glass fiber is allowed to stand for 30 minutes in an environment at 625 ° C. using an electric furnace, and after further removing the aqueous sizing agent (solid content) from the glass fiber, the aqueous sizing agent (solid content) is removed. The glass fiber weight W ₂ was measured.
The amount of the aqueous sizing agent attached to the glass fiber was calculated from the following equation.
Adhesion amount to glass fiber = ((glass fiber weight W ₁ after moisture removal) − (glass fiber weight W ₂ after water-based sizing agent (solid content) removal)) / (glass fiber weight W ₁ after moisture removal) × 100

(2) Unwinding tension of glass fiber The obtained glass fiber was unwound at a speed of 600 m / min, and the unwinding tension was measured using a tension meter (manufactured by Yokogawa Electronics Corporation).

(3) Static electricity characteristics of glass fiber The obtained glass fiber is wound up with a measuring machine, and an electrostatic sensor (ZJ-SD100 manufactured by OMRON Corporation) is installed at the lower part of the rotating body which is the winding part, and the yarn is arranged. The amount of static electricity generated in the process was measured. The number of windings was 100.

(4) Weaving property of glass fiber The wrapping and flying state of the glass fiber when weaving the glass fiber cloth using an air jet loom manufactured by Tsudakoma Kogyo Co., Ltd. is visually observed, and the weaving time is 1 hour. The number of times weaving was stopped was measured. The weaving of the glass fiber is stopped when the winding failure of the glass fiber around the feed roller occurs, or when the show topic occurs due to unstable feeding.
When it did not stop even once, “◎”, when it stopped once to 4 times, “◯”, when it stopped 5 times or more, “×”.

(5) Heat resistance of composite material The composite material was subjected to wet heat treatment and then given a thermal history by a solder bath, and the state of the composite material thereafter was evaluated. The wet heat treatment was performed using a pressure cooker under conditions of a water vapor pressure of 1.05 kg / cm ² G, an environmental temperature of 121 ° C., and 12 hours. The heat history by the solder bath was performed by immersing the wet-heat treated composite material in water at 20 to 25 ° C. for 15 minutes and then immersing it in a solder bath at 260 ° C. for 25 seconds.
Part of the composite material that has been immersed in the solder bath is scraped off from the composite material, and the surface of the composite material is observed using a flatbed scanner (manufactured by EPSON). The ratio of the area of (whitening part) was calculated | required.
When the ratio of the whitened portion on the surface of the composite material was less than 1%, “◎”, when it was 1% or more but less than 30%, “◯”, and when it was 30% or more, “x”.

(6) Hydroxyl value of (A) 10 g of (A) was dissolved in 5 mL of a mixture of acetic anhydride / pyridine (volume ratio 1/5), and then at 100 ° C. for 1 hour, acetic anhydride and (A) A hydroxyl group was reacted. Thereafter, distilled water was further added and stirred at 100 ° C. for 10 minutes to decompose excess acetic anhydride to obtain a sample solution. The sample solution was titrated with a 0.5 mol / L potassium hydroxide aqueous solution to obtain a titer W ₃ (mL). Similarly, titration was also performed when (A) was not used (only the above mixture), and a titer W ₄ (mL) was determined. The hydroxyl value was calculated from the following formula.
Hydroxyl value (mgKOH / g) = (W ₄ −W ₃ ) × f × 28.05 / 10
(F: Potency of 0.5 mol / L potassium hydroxide aqueous solution)

The material which comprises an aqueous sizing agent is shown below.
(1) (A)
(A1) Polyoxyethylene bisphenol A ether (manufactured by Yoshimura Oil Chemical Co., Ltd., GF690, hydroxyl value 123 mgKOH / g)
(A2) Polyoxyethylene bisphenol A ether (manufactured by Sanyo Chemical Industries, Newpol BPE-60, hydroxyl value 228 mgKOH / g)
(A3) Polyoxypropylene bisphenol A ether (manufactured by Sanyo Chemical Industries, Newpol BP-5P, hydroxyl value 211 mgKOH / g)

(2) (B)
(B1) Polyoxyethylene alkyl ester (manufactured by Yushi Kogyo Co., Ltd., Neulan)
(B2) Quaternary ammonium salt (Daiichi Kogyo Seiyaku Co., Ltd., Cathiogen)
(B3) Inorganic salt (manufactured by Ako Kasei Co., Ltd., magnesium chloride)

(3) (C)
(C1) Polyethylene glycol (manufactured by Sanyo Chemical Industries, PEG 600)

(4) (D)
(D1) Hindered amine (Yoshimura Oil Chemical Co., Ltd., VL-1, average particle size 40 nm)
(D2) Benzotriazole (manufactured by Senka, Shine Guard BZ-07)
(D3) Triazine (manufactured by Senka, Shine Guard TA-04)
(D4) Hindered phenol (Senca, Shineguard HP-12)

(5) Others ・ Starch (Piostarch manufactured by Nissho Chemical Co., Ltd.)
-Polyurethane acrylate aqueous dispersion (manufactured by Daicel Ornex, UCECOAT7655, particle size 0.15 μm)
・ Polymethyl methacrylate cross-linked water dispersion (manufactured by Nippon Shokubai Co., Ltd., MX-050W, particle size 0.20 μm)
・ Antistatic agent (manufactured by Yoshimura Oil Chemical Co., Permax F20)
・ Softening agent (CEF2 manufactured by Yoshimura Oil Chemical Co., Ltd.)

Examples 1-12, Comparative Examples 1-9
The types and mass parts (A), (B), (C) and (D) shown in Table 1 were mixed with water to produce an aqueous sizing agent having a solid content concentration of 4 to 8% by mass. .
The obtained aqueous sizing agent was attached to a glass yarn composed of a plurality of glass fiber filaments (total number of fibers: 40) spun from a nozzle, and the glass fibers were converged into one bundle (strand). The strand was then wound on a cake without twisting. The glass roving unraveled from the obtained cake was wound around a bobbin while twisting (twist number: 0.5Z) to obtain a glass fiber yarn (average fiber diameter: 4.1 μm, count: 1.3 tex). . Thus, the glass fiber by which the surface was processed was obtained.
The obtained glass fiber for weaving was woven using an air jet loom manufactured by Tsuda Koma Kogyo Co., Ltd. using both warp and weft to obtain a glass fiber cloth.
The obtained glass fiber cloth was opened with water, subjected to silane coupling treatment, dried in a drying process at 120 ° C., then immersed in an epoxy resin varnish, taken up from the varnish, and then 150 A heat treatment was performed at 5 ° C. for 5 minutes and at 170 ° C. for 1.5 to 2 hours to produce a cured composite material. The opening treatment with water was performed by applying a water pressure of 0.1 to 5.0 MPa, and the silane coupling treatment was performed using an aminosilane coupling agent. Moreover, the varnish which diluted 100 mass parts of epoxy resins of FR-4 composition of NBMA specification with 14 mass parts of methyl ethyl ketone was used as a varnish of an epoxy resin.

  Various measurements and evaluations were performed on the aqueous sizing agents, glass fibers, glass fiber cloths, and cured composite materials obtained in Examples 1 to 12 and Comparative Examples 1 to 9. Tables 1 and 2 show the measurement results and the evaluation results.

  Examples 1 to 12 all exhibited low unwinding tension, further suppressed generation of static electricity, and could be woven stably. Moreover, the obtained composite material was excellent in heat resistance.

In Example 2, since the content of (B) in the aqueous sizing agent was less than the preferred range, the amount of static electricity was slightly higher than in Example 1, and the weaving property was slightly worse.
In Example 3, since the content of (B) in the aqueous sizing agent was larger than the preferred range, the unraveling tension was higher and the weaving property was slightly worse as compared with Example 1. Further, the obtained composite material had slightly low heat resistance.
In Example 4, since the content of (C) in the aqueous sizing agent was less than the preferred range, the unraveling tension and the amount of static electricity were slightly higher than in Example 1, and the weaving property was slightly worse.
In Example 5, since the content of (C) in the aqueous sizing agent was larger than the preferred range, the unraveling tension and the amount of static electricity were slightly higher than in Example 1, and the weaving property was slightly worse. Further, the obtained composite material had slightly low heat resistance.
In Example 6, since the content of (D) in the aqueous sizing agent was less than the preferred range, the unraveling tension was slightly higher than in Example 1, and the weaving property was slightly worse.
In Example 7, since the content of (D) in the aqueous sizing agent was larger than the preferred range, the obtained composite material was slightly lower in heat resistance as compared with Example 1.
In Examples 8 to 10, since benzotriazole, triazine, and hindered phenol were used as (D) in the aqueous sizing agent, respectively, the unraveling tension and the amount of static electricity were slightly different from those in Example 1. It became high and the weaving property was slightly bad.
In Examples 11 and 12, since quaternary ammonium salt and magnesium chloride salt were used as (B) in the aqueous sizing agent, respectively, the unraveling tension and the amount of static electricity were slightly increased, and the weaving property was slightly higher. It was bad. Further, the obtained composite material had slightly low heat resistance.

In Comparative Example 1, since the content of (B) in the aqueous sizing agent was less than the range specified in the present invention, yarn breakage occurred at the spinning stage due to an increase in frictional force due to contact between the glass fiber and the guide, A continuous glass fiber could not be obtained.
In Comparative Example 2, since the content of (B) in the aqueous sizing agent was larger than the range specified in the present invention, the unwinding tension was high and the weaving property was poor. Further, the obtained composite material had low heat resistance.
In Comparative Example 3, since the content of (C) in the aqueous sizing agent was less than the range specified in the present invention, the film formation was deteriorated, the friction with the guide of the weaving machine was increased, and the weaving property was poor.
In Comparative Example 4, since the content of (C) in the aqueous sizing agent was larger than the range specified in the present invention, the slip property at the feeder portion was deteriorated and the weaving property was poor. Further, the obtained composite material had low heat resistance.
In Comparative Example 5, since the content of (D) in the aqueous sizing agent was less than the range specified in the present invention, the unwinding tension and the static electricity amount were high, and the weaving property was poor.
In Comparative Example 6, since the content of (D) in the aqueous sizing agent was larger than the range specified in the present invention, the winding at the feeder portion of the weaving machine became unstable and the weaving property was poor. Further, the obtained composite material had low heat resistance.
Since Comparative Example 7 contained starch without using (A) in the aqueous sizing agent, the resulting composite material had low heat resistance.
In Comparative Examples 8 and 9, polyurethane acrylate and polymethyl methacrylate cross-linked product were used without using (D) in the aqueous sizing agent, respectively, so that the unraveling tension and static electricity amount were high, and the weaving property was poor. .

Claims (6)

100 parts by mass of polyoxyalkylene bisphenol A ether (A), 3 to 20 parts by mass of one or more compounds (B) selected from polyoxyalkylene alkyl esters, quaternary ammonium salts and inorganic salts, and polyoxyalkylene glycol ( C) 100 to 200 parts by mass and one or more compounds (D) selected from benzotriazole, benzophenone, triazine, hindered phenol, benzoate and hindered amine (5) to 50 parts by mass, and starch and a silane coupling agent An aqueous sizing agent characterized by not containing. The aqueous sizing agent according to claim 1, wherein the hydroxyl value of (A) is 200 mgOH / g or less. A glass fiber having a surface treated with the aqueous sizing agent according to claim 1. A glass fiber cloth woven using the glass fiber according to claim 3. A prepreg comprising the glass fiber cloth according to claim 4. A composite material comprising the glass fiber cloth according to claim 4.