Scaling agent for long glass fibers

Abstract

To provide a sizing agent for a glass long fiber, which comprises an acrylic resin as a film-forming component, exhibits excellent effect of inhibiting fluff generation, and can imparting excellent heat-cleaning properties even under a low-temperature condition.SOLUTION: A sizing agent for a glass long fiber comprises (A) an acrylic resin, (B) fats and oils, and (C) a cationized cellulose and / or polyoxyethylene alkyl ether.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a sizing agent for glass fibers. More specifically, this invention relates to a sizing agent for glass fibers that contains an acrylic resin as a film-forming component and provides excellent fluff suppression and excellent heat cleaning properties even at low temperatures of less than 400°C. Furthermore, this invention relates to glass yarn prepared using the glass fiber sizing agent, glass cloth using the glass yarn, and a method for manufacturing the glass cloth. [Background technology]

[0002] Glass cloth is composed of glass yarn, which is made up of multiple glass filaments bundled together. Glass yarn and glass cloth for printed circuit boards are mainly manufactured through a glass yarn manufacturing process that includes a spinning process, and a glass cloth manufacturing process that includes a warp preparation process, a weaving process, a de-oiling process, and a surface treatment process. The operations in each process are as follows:

[0003] (1) Glass yarn manufacturing process (1-1) Spinning process Glass raw materials are melted in a glass melting furnace and drawn out as multiple glass long fibers. A sizing agent is applied to these multiple glass long fibers to bundle them together, forming a glass strand into a wound body called a cake. (1-2) Twisting process Glass strands are pulled from the cake and twisted in a twisting machine to create glass yarn. (2) Glass cloth manufacturing process (2-1) Preparation process Using glass yarn, the warp threads for the glass cloth are prepared through processes such as warping, sizing, and threading. (2-2) Weaving process Using the warp threads prepared above and the glass yarn used as the weft, the fabric is woven on an air-jet loom or the like to produce a raw cloth. (2-3) Heat cleaning process (heating and oil removal process) Sizing agents and other substances applied to the surface of glass fibers during the spinning process can hinder the adhesion between the glass fibers and the matrix resin during prepreg manufacturing. Therefore, a heat cleaning treatment (heat de-oiling treatment) is performed to remove organic components such as sizing agents adhering to the glass cloth by heating. (2-4) Surface treatment process In prepreg manufacturing, to improve the adhesion between the matrix resin and the glass fibers, the heat-cleaned glass cloth is treated with a silane coupling agent.

[0004] In the glass yarn and glass cloth manufacturing processes described above, the glass fibers may be partially cut, resulting in fuzzing. When fuzzing occurs in glass cloth, it can lead to defects such as poor insulation when used in printed circuit boards, so it is desirable to minimize fuzzing. The scrubbing agent used in the processing of glass fibers contributes significantly to suppressing fuzzing in glass cloth.

[0005] In sizing agents for glass fibers, starch or synthetic resins are frequently used as film-forming components. Furthermore, various glass fiber sizing agents have been proposed to improve the efficiency or eliminate the need for heat cleaning, and to enhance the suppression of fluff generation.

[0006] For example, Patent Document 1 reports that by using a sizing agent for glass fiber yarn containing a calcium compound, the time required for heat cleaning can be shortened and a uniform heat cleaning process can be achieved. Specifically, Patent Document 1 shows that by using a sizing agent for glass fiber yarn containing starch and calcium acetate, oxidation or decomposition can be promoted so that no organic matter remains even if the oxygen supply rate is slow, and the time required for heat cleaning can be shortened.

[0007] Patent Document 2 reports that by using a sizing agent for glass fiber yarns containing a water-soluble epoxy resin and treating yarns of 1.5 to 50 tex, it is possible to remove oil by water flow processing without heat cleaning, and it is possible to produce an ultra-thin treated glass fiber fabric with a single weight of 6 to 30 g / m , ,

[0010] , , , , , ,

[0011] , , , , , .

[0008] Patent Document 3 reports that by using a sizing agent for glass fibers containing starch and an acrylic copolymer with a degree of polymerization of 3×10 2 ~1×10<000000​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​According to the study by the present inventors, in the sizing agent for glass long fibers used in the glass yarn manufacturing process and the glass cloth manufacturing process, when starch is used as the film-forming component, the effect of suppressing the generation of fluff is higher than when a synthetic resin is used. And in the application of printed wiring boards where strong suppression of fluff generation is required, it is common to use starch as the film-forming component for the sizing agent of the glass long fibers constituting the glass cloth.

[0012] For example, when using starch as the film-forming component as in the sizing agent for glass long fibers disclosed in Patent Document 1, in order to remove the sizing agent for glass long fibers attached to the green cloth, in the heat cleaning treatment, it is necessary to perform it under high temperature conditions of 400 ° C or higher. In such a heat cleaning treatment under high temperature conditions, there is a drawback that the tensile strength of the glass long fibers, glass yarns, and glass cloth decreases. And the present inventors have particularly learned that when the above-mentioned glass long fibers and glass yarns are made finer and a thin glass cloth is obtained, the influence becomes greater. For example, when using starch as the film-forming component as in the sizing agent for glass long fibers disclosed in Patent Document 1, in order to remove the sizing agent for glass long fibers attached to the green cloth, in the heat cleaning treatment, it is necessary to perform it under high temperature conditions of 400 ° C or higher. In such a heat cleaning treatment under high temperature conditions, there is a drawback that the tensile strength of the glass long fibers, glass yarns, and glass cloth decreases. And the present inventors have particularly learned that when the above-mentioned glass long fibers and glass yarns are made finer and a thin glass cloth is obtained, the influence becomes greater.

[0013] [[ID=~8]]In addition, since the sizing agent for glass long fibers disclosed in Patent Documents 2 and 3 can be defatted by water washing, there is almost no problem of strength reduction in the obtained glass cloth. However, the present inventors have learned that the sizing agent for glass long fibers disclosed in Patent Documents 2 and 3 cannot sufficiently remove the sizing agent for glass long fibers by water washing for defatting, and the effect of suppressing the generation of fluff strongly required when making a thin glass cloth for printed wiring boards is not sufficient. [[ID=~10]]

[0014] [[ID=~11]] Conventionally, as an approach to improving the strength of glass cloth, examining the glass composition has been widely carried out. For example, it is known to use high-strength S glass or T glass instead of general-purpose E glass as the glass material constituting the glass fiber.

[0015] On the other hand, the inventors conceived of a method to address the problem of strength reduction due to heat cleaning of the thin glass cloth described above, which differs from the approach based on glass composition. Specifically, they conceived of suppressing strength reduction even in general-purpose E-glass compositions by adopting lower temperature conditions than conventional methods during the heat cleaning process. In other words, they conceived of using a synthetic resin with good heat-cleanability as the film-forming component of the sizing agent for glass long fibers, and setting the temperature conditions of the heat cleaning process to a lower temperature than conventional methods, thereby suppressing strength reduction due to the heat cleaning process.

[0016] Therefore, after repeated investigations, the inventors arrived at the conclusion that an acrylic resin capable of heat cleaning at relatively low temperatures should be used as a film-forming component. However, further investigations revealed that when an acrylic resin is used as a film-forming component, the effect of suppressing fluff generation is insufficient. In other words, the inventors found that a glass fiber sizing agent containing acrylic resin alone not only fails to suppress fluff generation, but also causes frequent yarn breakage during the spinning process, making it impossible to even obtain glass strands. Furthermore, when the inventors considered incorporating an oil as an auxiliary agent along with the acrylic resin in the glass fiber sizing agent, the suppression of fluff generation was insufficient, and the heat cleaning performance at low temperatures sometimes decreased, making it difficult to achieve a good balance between fluff suppression and heat cleaning performance.

[0017] Therefore, the object of the present invention is to solve the above problems and provide a scrubbing agent for glass long fibers that contains an acrylic resin as a film-forming component, and that provides excellent fluff suppression effect as well as excellent heat cleaning properties even under low temperature conditions. [Means for solving the problem]

[0018] The inventors of the present invention conducted thorough research to solve the above problems and found that a glass fiber scrubbing agent containing acrylic resin, oil and fat, and cationized cellulose and / or polyoxyethylene alkyl ether has excellent lint-suppressing effects and can fully possess the properties required when making thin glass cloth for printed circuit boards. Furthermore, the inventors found that this glass fiber scrubbing agent also has excellent heat-cleaning properties at low temperatures, exhibiting excellent heat-cleaning properties even when subjected to heat-cleaning treatment at temperatures below 400°C, and can suppress discoloration caused by residual organic matter (components of the glass fiber scrubbing agent) after heat-cleaning treatment, thus avoiding a decrease in strength due to heat-cleaning treatment at high temperatures. The present invention was completed by further research based on these findings.

[0019] In other words, the present invention provides inventions in the following embodiments. Item 1. A sizing agent for glass long fibers comprising (A) acrylic resin, (B) oil and fat, and (C) cationized cellulose and / or polyoxyethylene alkyl ether. Item 2. Glass yarn comprising glass long fibers having a film formed on its surface containing (A) acrylic resin, (B) oil and fat, and (C) cationized cellulose and / or polyoxyethylene alkyl ether. Item 3. A glass cloth formed from glass yarn made by bundling long glass fibers, The glass material constituting the long glass fibers is E-glass or a glass composition having a dielectric constant of less than 5.0 at a frequency of 1 MHz. The tensile strength of the glass yarn is 0.50 N / tex or more, and The ignition loss of the glass cloth is 0.10% by mass or less. Glass cloth. Item 4. Glass cloth as described in Item 3, used as a component material for printed circuit boards. Item 5. A method for manufacturing glass cloth, comprising the following steps A and B. Process A: A process of weaving raw cloth using the glass yarn described in item 2 as the warp and weft. Step B: A step of heat cleaning the raw cloth. Item 6. The method for manufacturing glass cloth according to Item 5, wherein the heat cleaning process in step B is performed under temperature conditions of 280 to 330°C. [Effects of the Invention]

[0020] The glass fiber scrubber of the present invention has an excellent effect in suppressing fluff generation, and therefore can provide glass yarn suitable as a raw material for thin glass cloth used in printed circuit boards. Furthermore, since the glass fiber scrubber of the present invention has good heat cleaning properties at low temperatures below 400°C, by using this glass fiber scrubber, it is possible to employ a heat cleaning treatment at low temperatures in the manufacture of glass cloth, and as a result, it is possible to suppress the decrease in tensile strength of glass yarn that occurs due to conventional heat cleaning treatment at high temperatures. [Modes for carrying out the invention]

[0021] 1. Swarming agent for glass long fibers The glass fiber sizing agent of the present invention is characterized by comprising (A) an acrylic resin, (B) an oil or fat, and (C) cationized cellulose and / or polyoxyethylene alkyl ether. By incorporating the above three components as an integral part of the glass fiber sizing agent of the present invention, it is possible to achieve an excellent effect in suppressing fluff generation, as well as good heat cleaning properties at low temperatures below 400°C, and it is possible to avoid a decrease in strength due to heat cleaning treatment at high temperatures. The glass fiber sizing agent of the present invention will be described in detail below.

[0022] In this specification, "heat-cleanability" means the ability to remove non-volatile organic components (non-volatile organic components derived from glass fiber scrubbers, etc.) adhering to the glass yarn by heat cleaning treatment.

[0023] [(A) Acrylic resin] The present invention provides a sizing agent for glass long fibers, which includes an acrylic resin as a film-forming component (simply "component (A)"). It includes (sometimes written as "). The acrylic resin used in this invention is preferably capable of forming an emulsion in water.

[0024] Acrylic resins are polymers obtained by polymerization using (meth)acrylic acid and / or (meth)acrylic acid derivatives as polymerizable monomers. In this specification, "(meth)acrylic acid" is a compound name that includes both acrylic acid and methacrylic acid.

[0025] Examples of (meth)acrylic acids include acrylic acid and methacrylic acid.

[0026] As for (meth)acrylic acid derivatives, any derivatives capable of radical polymerization are acceptable, such as carboxyl group-containing (meth)acrylic acid monomers including β-carboxyethyl (meth)acrylate, 2-(meth)acryloylpropionic acid, β-(meth)acryloyloxyethyl hydrogen succinate, and salts thereof; methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate (meth)acrylic acid ester monomers such as hexyl (meth)acrylate, cyclohexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, dodecyl (meth)acrylate, stearyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate; 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate Fluorine-containing (meth)acrylic acid monomers such as perfluorocyclohexyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, and β-(perfluorooctyl)ethyl (meth)acrylate; glycidyl group-containing (meth)acrylic acid monomers such as glycidyl (meth)acrylate; hydroxyl group monomers such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, and glycerol mono(meth)acrylate. Monomers containing (meth)acrylic acid; amino group-containing (meth)acrylic acid monomers such as aminoethyl (meth)acrylate, N-monoalkylaminoalkyl (meth)acrylate, and N,N-dialkylaminoalkyl (meth)acrylate; aziridinyl group-containing (meth)acrylic acid monomers such as 2-aziridinylethyl (meth)acrylate; allyl group-containing (meth)acrylic acid monomers such as allyl (meth)acrylate; cyclopentenyl group-containing (meth)acrylic acid monomers such as dicyclopentenyl (meth)acrylate;Di(meth)acrylic acid monomers such as ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, diallyl phthalate, and divinylbenzene; (meth)acrylic acid monomers containing methylolamide groups or their alkoxy derivatives such as N-methylol(meth)acrylamide, N-isopropoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, and N-isobutoxymethyl(meth)acrylamide; γ-(meth)acryloxypropyltrimethoxysilane, γ-(meth)acryloxypropyltriethoxysilane, γ-(meth)acryloxypropyl Examples include silyl group-containing (meth)acrylic acid monomers such as pyrmethyldimethoxysilane, γ-(meth)acryloxypropylmethyldiethoxysilane, and γ-(meth)acryloxypropyltriisopropoxysilane; isocyanate group-containing and / or blocked isocyanate group-containing (meth)acrylic acid monomers such as (meth)acryloyl isocyanate and (meth)acryloyl isocyanate ethyl phenol or methyl ethyl ketoxime adducts; amide group-containing (meth)acrylic acid monomers such as (meth)acrylamide, N-monoalkyl(meth)acrylamide, and N,N-dialkyl(meth)acrylamide; carbonyl group-containing (meth)acrylic acid monomers such as diacetone(meth)acrylamide; and acetoacetyl group-containing (meth)acrylic acid monomers such as acetoacetoxyethyl(meth)acrylate.

[0027] In the acrylic resin used in the present invention, one of (meth)acrylic acid and (meth)acrylic acid derivatives may be used alone as the polymerizable monomer, or two or more of these may be used in combination.

[0028] The acrylic resin used in the present invention may be a homopolymer obtained by polymerizing only one of (meth)acrylic acid and (meth)acrylic acid derivatives, a copolymer obtained by polymerizing two or more of (meth)acrylic acid and (meth)acrylic acid derivatives, or a copolymer obtained by polymerizing one or more of (meth)acrylic acid and (meth)acrylic acid derivatives with one or more other polymerizable monomers.

[0029] When the acrylic resin is a copolymer of (meth)acrylic acid and / or a (meth)acrylic acid derivative and other polymerizable monomers, the other polymerizable monomer is not particularly limited as long as it can copolymerize with (meth)acrylic acid and / or a (meth)acrylic acid derivative, but examples include crotonic acid, itaconic acid, maleic acid, fumaric acid, itaconic acid, maleic acid, maleic anhydride, itaconic anhydride, half esters thereof, and salts thereof; unsaturated dicarboxylic acid polymerizable monomers; glycidyl group-containing polymerizable monomers such as allyl glycidyl ether; vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, γ-(meth)acryloxypropyltrimethoxysilane, γ-(meth)acryloxypropyltriethoxysilane, N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane and so Examples include silyl group-containing polymerizable monomers such as hydrochloride salts; oxazoline group-containing polymerizable monomers such as 2-isopropenyl-2-oxazoline and 2-vinyl-2-oxazoline; carbonyl group-containing polymerizable monomers such as acrolein; vinyl sulfonic acid-based polymerizable monomers such as vinyl sulfonic acid and styrene sulfonic acid; vinyl ester-based polymerizable monomers such as vinyl acetate, vinyl propionate, vinyl butyrate, and vinyl versatate; vinyl ether-based polymerizable monomers such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, amyl vinyl ether, and hexyl vinyl ether; aromatic vinyl compound-based polymerizable monomers such as styrene, α-methylstyrene, vinyltoluene, vinylanisole, α-halostyrene, vinylnaphthalene, and divinylstyrene; and isoprene, chloroprene, butadiene, ethylene, tetrafluoroethylene, vinylidene fluoride, and N-vinylpyrrolidone. These polymerizable monomers may be used individually or in combination of two or more.

[0030] In the glass fiber sizing agent of the present invention, the acrylic resin may be used alone or in combination of two or more types.

[0031] The average particle size (median diameter) of the acrylic resin used in this invention is not particularly limited, but for example, it can be approximately 100 to 1500 nm. If the average particle size of the acrylic resin is within this range, the drying properties of the film during film formation can be improved. In this invention, the average particle size of the acrylic resin is a value measured by a dynamic light scattering photometer (Otsuka Electronics LPA system; ELSZ-2000ZS) under the following conditions: After diluting the resin emulsion with distilled water to a measurable concentration, fill it into a four-sided transparent 10 mm square cell, irradiate it with a He-Ne laser at 25°C, and measure to determine the number-average particle size value.

[0032] Furthermore, the molecular weight of the acrylic resin used in the present invention is not particularly limited, but for example, the weight-average molecular weight determined by the polystyrene equivalent value using the GPC method is 1,000 to 1,000,000, preferably 2,000 to 500,000, and more preferably 100,000 to 500,000. In the present invention, the weight-average molecular weight of the acrylic resin is the value measured under the following conditions. GPC equipment: Prominence manufactured by Shimadzu Corporation Columns: SHODEX KF-800P, KF-005, KF-003, KF-001 (use 4 in series) Mobile phase: tetrahydrofuran Flow rate: 1mL / min Column oven temperature: 40℃ Detector: RI Molecular weight conversion: Standard polystyrene

[0033] Furthermore, while there are no particular limitations on the weight loss rate at 330°C in TGA (thermogravimetric analysis) for the acrylic resin used in the present invention, examples include 95% by mass or more, preferably 98.0 to 99.9% by mass. In the present invention, the weight loss rate at 330°C in TGA (thermogravimetric analysis) of the acrylic resin is determined by heat-treating the acrylic resin at 110°C for 60 minutes to dry it, then returning it to room temperature and weighing it to 10 to 30 mg as a measurement sample. The TGA measurement is performed by raising the temperature at a rate of 10°C / min and measuring the weight when it reaches 330°C, thereby calculating the weight loss rate.

[0034] In the glass fiber sizing agent of the present invention, it is desirable that the acrylic resin be included in the form of an emulsion. The acrylic resin emulsion can be obtained by known methods. Methods for producing the acrylic resin emulsion include, for example, (i) a method of polymerizing by mixing water, a polymerizable monomer, an emulsifier, a polymerization initiator, etc. all at once; (ii) a pre-emulsion method in which a pre-emulsion of water, a polymerizable monomer, and an emulsifier is pre-mixed is dropped; or (iii) Examples include monomer dropwise addition, in which polymerizable monomers, polymerization initiators, etc., are dropped into a reaction vessel containing a polymer resin.

[0035] The type of emulsifier added to the acrylic resin emulsion is not particularly limited, but examples include polyoxyalkylene alkyl ether type surfactants such as polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene alkyl ether, and polyoxypropylene alkyl ether. Furthermore, the type of polymerization initiator added to the acrylic resin emulsion is not particularly limited, but examples include persulfates such as sodium persulfate, potassium persulfate, and ammonium persulfate.

[0036] A preferred embodiment of the acrylic resin emulsion used in the present invention is one prepared by heating a mixture of water, (meth)acrylic acid and / or a (meth)acrylic acid derivative as a polymerizable monomer, a polyoxyalkylene alkyl ether type surfactant as an emulsifier, and a persulfate as a polymerization initiator.

[0037] The ratio of the mass of component (A) to 100 parts by mass of the total nonvolatile components contained in the glass fiber sizing agent of the present invention is, for example, 10 to 80 parts by mass, preferably 10 to 50 parts by mass, and more preferably 15 to 40 parts by mass. In this invention, "nonvolatile components" refers to the oven-dried components obtained when a constant weight is reached after heat treatment at 110°C under normal pressure to remove solvents, etc.

[0038] Furthermore, the concentration of component (A) in the glass fiber sizing agent of the present invention can be, for example, 0.5 to 1.0% by mass, preferably 0.6 to 0.9% by mass, and more preferably 0.7 to 0.9% by mass.

[0039] [(B) Fats and oils] The glass fiber sizing agent of the present invention contains an oil or fat (sometimes simply referred to as "component (B)"). The oil or fat primarily functions as a lubricant between the glass fibers, thereby imparting flexibility to the glass yarn and providing an excellent effect in suppressing fluff generation.

[0040] The type of oil or fat used in this invention is not particularly limited, but examples include animal oils, vegetable oils, esters of higher fatty acids, hydrocarbon oils, and the like.

[0041] Examples of animal oils include beef tallow, lard, horse oil, mink oil, fish oil, egg yolk oil, and hydrogenated versions of these.

[0042] Examples of vegetable oils include soybean oil, rapeseed oil, corn oil, sesame oil, rice germ oil, safflower oil, cottonseed oil, coconut oil, almond oil, macadamia nut oil, olive oil, avocado oil, camellia oil, peach kernel oil, carnauba wax, candelilla wax, castor oil, jojoba oil, cocoa butter, kukui nut oil, shea butter, evening primrose oil, perilla oil, tea seed oil, palm kernel oil, palm oil, peanut oil, sunflower oil, grape seed oil, meadowfoam oil, and hydrogenated oils of these.

[0043] Examples of esters of higher fatty acids include esters of higher fatty acids having 12 to 22 carbon atoms and monohydric alcohols having 1 to 22 carbon atoms, preferably esters of higher saturated fatty acids having 16 to 22 carbon atoms and monohydric alcohols having 1 to 10 carbon atoms, and more preferably esters of higher saturated fatty acids having 16 to 22 carbon atoms and monohydric alcohols having 1 to 6 carbon atoms. Specific examples of esters of higher fatty acids include dodecyl stearate, stearyl stearate, and butyl stearate.

[0044] Examples of hydrocarbon oils include paraffin wax, liquid paraffin, squalane, petrolatum, ceresin wax, microcrystalline wax, and physerotropus wax.

[0045] Among these oils and fats, preferred examples include esters of higher fatty acids and hydrocarbon oils.

[0046] In the sizing agent for glass long fibers of the present invention, one type of oil or fat may be used alone, or two or more types may be used in combination.

[0047] In the glass fiber sizing agent of the present invention, it is desirable that the oil or fat is included in an emulsified state. Emulsification of the oil or fat can be carried out by known methods using emulsifiers or the like.

[0048] The ratio of the mass of component (B) to 100 parts by mass of the total nonvolatile components contained in the glass fiber sizing agent of the present invention is, for example, 20 to 80 parts by mass, preferably 50 to 80 parts by mass, and more preferably 50 to 70 parts by mass.

[0049] In the glass fiber sizing agent of the present invention, the ratio of component (B) to component (A) is not particularly limited, but for example, 150 to 300 parts by mass, preferably 220 to 300 parts by mass of component (B) per 100 parts by mass of component (A).

[0050] Furthermore, the concentration of component (B) in the glass fiber sizing agent of the present invention can be, for example, 1.0 to 3.0% by mass, preferably 1.5 to 2.5% by mass, and more preferably 1.8 to 2.2% by mass.

[0051] [(C) Polyoxyethylene alkyl ether and / or cationized cellulose] The glass fiber scrubber of the present invention contains polyoxyethylene alkyl ether and / or cationized cellulose (sometimes simply referred to as "component (C)"). In the present invention, polyoxyethylene alkyl ether and / or cationized cellulose mainly function as a lubricating component between glass fibers, thereby imparting flexibility to the glass yarn, providing an excellent effect in suppressing fluff generation, and improving heat cleaning properties at low temperatures below 400°C.

[0052] A polyoxyethylene alkyl ether is a compound in which a polyoxyethylene chain and an alkyl group are linked by an ether bond. The number of carbon atoms in the alkyl group in the polyoxyethylene alkyl ether used in this invention can be, for example, 6 to 30, preferably 12 to 24. Furthermore, the number of moles of ethylene oxide added to the polyoxyethylene alkyl ether used in this invention can be, for example, 1 to 60, preferably 3 to 50.

[0053] Examples of polyoxyethylene alkyl ethers include polyoxyethylene butyl ether, polyoxyethylene octyl ether, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, and polyoxyethylene behenyl ether.

[0054] Cationized cellulose refers to cellulose into which a positively charged group has been introduced through modification. Modification is preferably carried out on the hydroxyl groups in the glucose residues of cellulose, and such modification can introduce a positively charged group, for example, via an ester bond or ether bond. Examples of cationized cellulose include cellulose into which a group exhibiting an onium ion (positively charged) such as an ammonium ion, phosphonium ion, or sulfonium ion has been introduced in water through modification, and preferably cellulose into which a group exhibiting an ammonium ion has been introduced in water. Note that cationized cellulose may form salts with negatively charged atoms or molecules. Furthermore, cationized cellulose only needs to be soluble in the solvent used in this invention; the degree of modification, molecular weight, etc., are not particularly limited.

[0055] A preferred example of the cationized cellulose used in the present invention is hydroxyalkylcellulose having a quaternary ammonium group. Specifically, examples of hydroxyalkylcellulose having a quaternary ammonium group include O-(2-hydroxy-3-(trimethylammonio)propyl)hydroxyethylcellulose chloride, O-(2-hydroxy-3-(lauryldimethylammonio)propyl)hydroxyethylcellulose chloride, and hydroxyethylcellulose dimethyldiallylammonium chloride. Among these, O-(2-hydroxy-3-(trimethylammonio)propyl)hydroxyethylcellulose chloride is preferred.

[0056] The glass fiber scrubber of the present invention may contain one of polyoxyethylene alkyl ether and cationized cellulose alone, or it may contain two or more of these in combination.

[0057] Among polyoxyethylene alkyl ethers and cationized celluloses, polyoxyethylene alkyl ethers are preferred from the viewpoint of further improving the effect of suppressing fluff generation and the heat cleaning properties under low temperature conditions.

[0058] When component (C) contains polyoxyethylene alkyl ether, the mass ratio of polyoxyethylene alkyl ether to 100 parts by mass of the total nonvolatile components contained in the glass long fiber sizing agent of the present invention is, for example, 1 to 15 parts by mass, preferably 1 to 10 parts by mass, and more preferably 2 to 6 parts by mass.

[0059] When component (C) contains polyoxyethylene alkyl ether, the ratio of polyoxyethylene alkyl ether to component (A) is, for example, 10 to 50 parts by mass, preferably 10 to 20 parts by mass, of polyoxyethylene alkyl ether per 100 parts by mass of component (A).

[0060] Furthermore, when component (C) includes polyoxyethylene alkyl ether, the concentration of polyoxyethylene alkyl ether in the glass fiber sizing agent of the present invention can be, for example, 0.1 to 0.4% by mass, preferably 0.1 to 0.3% by mass, and more preferably 0.1 to 0.2% by mass.

[0061] (C) When cationized cellulose is included as component, the mass ratio of cationized cellulose to 100 parts by mass of the total nonvolatile components contained in the glass long fiber sizing agent of the present invention is, for example, 0.1 to 2 parts by mass, preferably 0.1 to 1 part by mass, and more preferably 0.2 to 0.8 parts by mass.

[0062] When component (C) contains cationized cellulose, the ratio of cationized cellulose to component (A) is, for example, 2 to 8 parts by mass, preferably 2 to 5 parts by mass, of cationized cellulose per 100 parts by mass of component (A).

[0063] Furthermore, when component (C) includes cationized cellulose, the concentration of cationized cellulose in the glass fiber sizing agent of the present invention can be, for example, 0.01 to 0.05% by mass, preferably 0.01 to 0.04% by mass, and more preferably 0.01 to 0.03% by mass.

[0064] [Total amount of components (A) to (C)] The ratio of the total amount of components (A) to (C) (sum of the content of components (A) to (C)) to 100 parts by mass of the total nonvolatile components contained in the glass fiber sizing agent of the present invention is, for example, 50 parts by mass or more, preferably 60 parts by mass or more. The upper limit of this ratio is, for example, 100 parts by mass, 99 parts by mass, 95 parts by mass, or 80 parts by mass.

[0065] [Non-volatile components other than components (A) to (C)] In addition to components (A) to (C), the glass fiber scrubbing agent of the present invention may contain other non-volatile components to the extent that it provides the effects of the present invention.

[0066] Examples of non-volatile components that can be incorporated into the glass fiber sizing agent of the present invention include softening agents. Examples of softening agents include polyamide derivatives, fatty acid amide derivatives, alkylamide derivatives, amino-modified silicon derivatives, and polyamine derivatives. Among these softening agents, alkylamide derivatives are preferred.

[0067] Examples of alkylamide derivatives include compounds represented by the following general formula (1). In general formula (1), R 1 R represents a linear or branched alkyl or alkenyl group. 1The number of carbon atoms in the alkyl or alkenyl group can be, for example, 7 to 23, preferably 10 to 18, and more preferably 12 to 16. Also, in general formula (1), R 2 This represents a methyl group, an ethyl group, a hydroxymethyl group, or a hydroxyethyl group. [ka]

[0068] When the glass fiber sizing agent of the present invention contains a softening agent component, the ratio of the mass of the softening agent component to 100 parts by mass of the total nonvolatile components contained in the glass long fiber sizing agent of the invention is, for example, 1 to 12 parts by mass, preferably 3 to 6 parts by mass.

[0069] Furthermore, when the glass fiber sizing agent of the present invention contains a softening agent component, the concentration of the softening agent component in the glass long fiber sizing agent of the present invention can be, for example, 0.03 to 0.3% by mass, preferably 0.05 to 0.2% by mass, and more preferably 0.1 to 0.2% by mass.

[0070] Another example of a non-volatile component that can be incorporated into the glass fiber sizing agent of the present invention is polyethylene glycol. When polyethylene glycol is included, it becomes possible to further improve the effect of suppressing fluff generation and the heat cleaning properties under low temperature conditions.

[0071] The average molecular weight of polyethylene glycol used in the present invention is not particularly limited, but for example, a weight-average molecular weight obtained by the polystyrene equivalent value using the GPC method is 100 to 1000, preferably 200 to 500.

[0072] When polyethylene glycol is included in the glass fiber sizing agent of the present invention, the ratio of polyethylene glycol to 100 parts by mass of the total nonvolatile components contained in the glass long fiber sizing agent of the present invention is, for example, 15 to 25 parts by mass.

[0073] Furthermore, when polyethylene glycol is included in the glass fiber sizing agent of the present invention, the concentration of polyethylene glycol in the glass long fiber sizing agent of the present invention can be, for example, 0.5 to 0.8% by mass, preferably 0.6 to 0.8% by mass, and more preferably 0.7 to 0.8% by mass.

[0074] Furthermore, it is desirable that the glass fiber sizing agent of the present invention contains an emulsifier in addition to the non-volatile components mentioned above in order to emulsify the acrylic resin and oils. The concentration of the emulsifier in the glass fiber sizing agent of the present invention should be appropriately set within a range that can emulsify the acrylic resin and oils, depending on the type of emulsifier used.

[0075] In the glass fiber sizing agent of the present invention, when non-volatile components other than components (A) to (C) are included, the ratio of the total amount of non-volatile components other than components (A) to (C) (total amount of non-volatile components other than components (A) to (C)) to 100 parts by mass of the total amount of non-volatile components contained in the glass fiber sizing agent of the present invention is, for example, 40 parts by mass or less, preferably 10 to 40 parts by mass, and more preferably 20 to 40 parts by mass.

[0076] [Total concentration of non-volatile components] In the glass fiber sizing agent of the present invention, the total concentration of nonvolatile components (the sum of components (A) to (C) and other nonvolatile components) is, for example, 2.5 to 4.5% by mass, preferably 3.0 to 4.0% by mass.

[0077] [Aqueous solvent (volatile component)] 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 mixed solvents 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.

[0078] The concentration of the aqueous solvent in the glass fiber sizing agent of the present invention should be such that it occupies the remainder excluding the non-volatile components.

[0079] [Manufacturing method] The glass fiber sizing agent of the present invention can be obtained by mixing predetermined amounts of components (A) to (C), other non-volatile components as needed, and an aqueous solvent. Alternatively, an emulsified glass fiber sizing agent can be easily obtained by preparing an acrylic resin emulsion as component (A) and an emulsified oil as component (B) in advance, and then mixing the acrylic resin emulsion and the emulsified oil with the other components.

[0080] [How to use] The glass fiber scrubber of the present invention is used to bundle glass fibers to prepare glass yarn (glass fiber bundles). Glass fibers treated with the glass fiber scrubber of the present invention have their surfaces coated with a film of non-volatile components.

[0081] The type of glass fiber 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, quartz glass, etc. Among these, E glass is preferred from the viewpoint of further improving heat cleaning performance under low temperature conditions. In the present invention, E glass is specifically a glass material consisting of a glass composition containing 52-56% by mass of SiO2, 12-16% by mass of Al2O3, 20-25% by mass of CaO+MgO, and 5-10% by mass of B2O3.

[0082] Furthermore, another suitable example of glass fibers to be treated with the glass fiber sizing agent of the present invention is glass fibers having low dielectric properties. Examples of glass compositions constituting glass fibers having low dielectric properties include glass compositions containing 45-60% by mass of SiO2, 15-35% by mass of B2O3, and 10-20% by mass of Al2O3. A suitable example of glass fibers having low dielectric properties is a glass composition having a dielectric constant of less than 5.0 at a frequency of 1 MHz, and more specifically, a glass composition containing 50-56% by mass of SiO2, 20-30% by mass of B2O3, and 10-20% by mass of Al2O3. In this specification, "dielectric constant" refers to the relative permittivity, which is the ratio to the permittivity of vacuum. In this specification, "dielectric constant at a frequency of 1 MHz" is a value measured in accordance with ASTM D150-87, with the measurement temperature set to 20°C.

[0083] The fiber diameter of the glass long fibers to be treated with the glass long fiber sizing agent of the present invention is not particularly limited, but from the viewpoint of more effectively exhibiting the effect of suppressing fluff generation and heat cleaning properties under low temperature conditions, it is preferably 2 to 5 μm, and more preferably 2 to 4.5 μm.

[0084] The count of the glass fibers to be treated with the glass fiber sizing agent of the present invention is not particularly limited, but from the viewpoint of more effectively exhibiting the effect of suppressing fluff generation and heat cleaning properties under low temperature conditions, preferably 1 to 12 tex, more preferably 1 to 5 tex, and especially preferably 1 to 3 tex are used.

[0085] The number of glass filaments to be bundled into a single glass yarn using the glass filament sizing agent of the present invention is not particularly limited, but for example, it can be 40 to 400, preferably 40 to 200, and more preferably 40 to 100.

[0086] To prepare glass yarn by processing glass filaments using the glass filament sizing agent of the present invention, the glass filaments are coated with the glass filament sizing agent of the present invention, bundled, and dried. To apply the glass filament sizing agent of the present invention to the glass filaments, for example, a roller-type or belt-type applicator, a spray, etc., can be used. To bundle the glass filaments coated with the glass filament sizing agent of the present invention, a known bundling machine can be used. Furthermore, drying after bundling can be carried out, for example, under temperature conditions in the range of room temperature to 150°C. Thus, by coating the glass filament sizing agent of the present invention to the glass filaments, bundling them, and then drying, volatile components such as aqueous solvents are removed, and a glass yarn is obtained in which a film of non-volatile components contained in the glass filament sizing agent of the present invention is formed on the surface of the glass filaments. The glass yarn thus obtained can be twisted in a twisting machine as needed and used as a raw material yarn for glass cloth.

[0087] The amount of the glass fiber scrubbing agent of the present invention applied to the glass fibers to be treated should be set appropriately so as to be effective in suppressing fluff generation. For example, it should be set within a range where the ignition loss of the scrubbing agent of the present invention is 0.3 to 2.0 mass%, preferably 0.3 to 1.2 mass%. The ignition loss of the glass yarn is substantially equivalent to the amount of non-volatile components contained in the glass fiber scrubbing agent of the present invention that are applied, and is a value measured according to the method specified in "7.3.2 Ignition Loss" of "General Test Methods for Glass Fibers" in JIS R 3420 2013.

[0088] 2. Glass yarn The glass yarn of the present invention is characterized by comprising glass long fibers having a coating formed on its surface containing (A) acrylic resin, (B) oil and fat, and (C) cationized cellulose and / or polyoxyethylene alkyl ether.

[0089] The glass yarn of the present invention can be obtained by treating glass fibers with the glass fiber sizing agent described above. In the glass yarn of the present invention, the type of glass fiber used, fiber diameter, yarn count, etc., are as described in the "1. Glass Fiber Sizing Agent" section above. The amount of film formed on the glass fibers is the same as the ignition loss described in the "1. Glass Fiber Sizing Agent" section above. Furthermore, the types of (A) acrylic resin, (B) oils and fats, and (C) cationized cellulose and / or polyoxyethylene alkyl ether contained in the film formed on the glass fibers, the types of other non-volatile components that may be contained in the film, and the composition of the film are the same as the types of each non-volatile component and their compositions described in the "1. Glass Fiber Sizing Agent" section above.

[0090] 3. Glass cloth The glass cloth of the present invention is obtained by weaving using the glass yarn as the raw material and then subjecting it to a heat cleaning treatment. Since the glass cloth of the present invention is manufactured using glass yarn on which a film containing (A) acrylic resin, (B) oils and fats, and (C) cationized cellulose and / or polyoxyethylene alkyl ether is formed, low temperature conditions of less than 400°C can be used in the heat cleaning treatment during manufacturing. As a result, the decrease in tensile strength and other properties of the glass cloth due to the heat cleaning treatment is suppressed, and it can be made to have excellent tensile strength.

[0091] The weave structure of the glass cloth of the present invention is not particularly limited, but examples include plain weave, satin weave, nanako weave, leno weave, gauze weave, twill weave, etc. The weave density of the glass cloth of the present invention is not particularly limited, but examples include approximately 10 to 150 threads / 25 mm for both warp and weft, and approximately 50 to 130 threads / 25 mm for both warp and weft.

[0092] The thickness of the glass cloth of the present invention is not particularly limited. However, from the viewpoint of more effectively suppressing the decrease in the tensile strength and the like of the glass cloth due to the heat cleaning treatment and providing excellent tensile strength, it is about 8 to 20 μm, preferably about 8 to 15 μm, and more preferably about 8 to 13 μm.

[0093] The mass of the glass cloth of the present invention is not particularly limited. However, from the viewpoint of more effectively suppressing the decrease in the tensile strength and the like of the glass cloth due to the heat cleaning treatment and providing excellent tensile strength, it is 3 to 30 g / m 2 or so, preferably 3 to 20 g / m 2 or so, and more preferably 7 to 14 g / m 2 or so can be mentioned.

[0094] In addition, in the glass cloth obtained by using glass yarn treated with a starch-based sizing agent, a heat cleaning treatment under high temperature conditions of 400 °C or higher is required. Therefore, there is a drawback that the tensile strength of the glass yarn constituting the glass cloth inevitably decreases. For example, when the heat cleaning treatment is carried out under the conditions of 400 °C for 60 hours, the tensile strength of the glass yarn decreases to less than half of that before the heat cleaning treatment. On the other hand, in the glass cloth of the present invention, since it is manufactured using the above glass yarn, a low temperature condition of less than 400 °C can be adopted in the heat cleaning treatment. As a result, the glass yarn constituting the glass cloth can have excellent tensile strength. In view of such an effect of the present invention, as a preferred embodiment of the glass cloth of the present invention, the glass yarn constituting the glass cloth has a high tensile strength. Specifically, those having a tensile strength of 0.45 N / tex or more, preferably 0.45 to 0.60 N / tex, and more preferably 0.50 to 0.60 N / tex can be mentioned. The glass cloth containing such a glass yarn having such a tensile strength can be preferably obtained by performing a heat cleaning treatment under a temperature condition of 280 to 330 °C.

[0095] Furthermore, the ignition loss of the glass cloth of the present invention can be, for example, 0.10% by mass or less, preferably 0.04 to 0.10% by mass. The ignition loss of the glass cloth substantially corresponds to the amount of non-volatile organic components adhering to the glass cloth, and is a value measured according to the method specified in "7.3.2 Ignition Loss" of "General Test Methods for Glass Fibers" in JIS R 3420 2013.

[0096] Furthermore, a preferred embodiment of the glass cloth of the present invention is a glass material in which the glass material is E-glass or a glass composition having a dielectric constant of less than 5.0 at a frequency of 1 MHz, the tensile strength of the glass yarn constituting the glass cloth is 0.50 N / tex or more, preferably 0.45 to 0.60 N / tex, more preferably 0.50 to 0.60 N / tex, and the ignition loss is 0.10 mass% or less, preferably 0.04 to 0.10 mass%.

[0097] The applications of the glass cloth of the present invention are not particularly limited and can be used in any application where glass cloth has been conventionally applied. Furthermore, in the case of glass cloth for printed circuit boards (glass cloth used as a core material for printed circuit boards), there is a requirement to reduce the thickness in order to accommodate high-density mounting and miniaturization, but conventional glass cloths have the disadvantage of being prone to fuzzing. In contrast, the glass cloth of the present invention can suppress the generation of fuzz even when thin, and can fully satisfy the required characteristics of glass cloth for printed circuit boards. Considering these effects of the present invention, a suitable example of an application for the glass cloth of the present invention is glass cloth for printed circuit boards, in particular glass cloth for thin printed circuit boards. For example, the thickness of the thin glass cloth can be 8 to 20 μm.

[0098] The glass cloth of the present invention is obtained by weaving using the glass yarn as the raw material and then performing a heat cleaning treatment. Specifically, the glass cloth of the present invention can be obtained through the following steps A and B. Process A: A process of weaving a raw cloth using the glass yarn as the warp and weft. Step B: A step of heat cleaning the raw cloth.

[0099] In step A, the glass yarn can be used as the warp and weft threads, and the glass cloth can be woven using a known method depending on the weave structure and weave density of the glass cloth.

[0100] Furthermore, the warp threads used in step A may be further treated with a secondary sizing agent. The composition of the secondary sizing agent used is not particularly limited, but preferably it has the same composition as the glass filament sizing agent.

[0101] The temperature conditions for the heat cleaning process in step B are not particularly limited and can be set appropriately so that the ignition loss of the resulting glass cloth falls within the range described above, for example, 250 to 600°C. Furthermore, as mentioned above, the glass cloth of the present invention can be subjected to heat cleaning at low temperatures of less than 400°C, and as a result, the decrease in the tensile strength of the glass yarn due to the heat cleaning process can be suppressed. Therefore, from the viewpoint of suppressing the decrease in tensile strength, the conditions for the heat cleaning process are preferably less than 400°C, more preferably 280 to 390°C, even more preferably 280 to 330°C, and particularly preferably 290 to 330°C.

[0102] The time for the heat cleaning process in step B can be set appropriately so that the loss on ignition of the glass cloth obtained is within the range described above, depending on the temperature conditions used. For example, when the glass cloth is a roll product (a product in which glass cloth is wound around a core) and the heat cleaning process is performed on the roll product, the time can be 48 to 96 hours, preferably 48 to 72 hours, and more preferably 48 to 60 hours.

[0103] Furthermore, the present invention's method for manufacturing glass cloth for printed circuit boards may include, if necessary, other processing steps besides steps A and B. Examples of such processing steps include a fiber-opening process for widening the glass yarn constituting the glass cloth, and a surface treatment process using a silane coupling agent. [Examples]

[0104] The present invention will be described in detail below with reference to examples. However, the present invention is not limited to the following examples.

[0105] 1. Test Method 1-1. Loss of weight upon ignition of glass yarn and glass cloth The ignition loss of glass yarn and glass cloth was measured and calculated according to the method specified in "7.3.2 Ignition Loss" of "General Test Methods for Glass Fibers" in JIS R 3420 2013. Furthermore, for the glass yarns of Examples 4-6 and Comparative Example 5, the ignition loss (ignition loss after heat treatment condition 1 (330°C)) was also measured after further heat treatment under heat treatment condition 1 and returning to room temperature. • Heat treatment condition 1: Suspended in a hot air furnace at 330°C and heated for 60 minutes.

[0106] 1-2. Single fiber diameter (μm) of glass long fibers The single fiber diameter of the glass long fibers was measured and calculated according to the method specified in Method B (cross-sectional method) of "7.6 Single Fiber Diameter" of "General Test Methods for Glass Fibers" in JIS R 3420 2013.

[0107] 1-3. Glass yarn count (tex) The yarn count of the glass yarn was measured and calculated according to the method specified in "7.1 Yarn Count" of "General Test Methods for Glass Fibers" in JIS R 3420 2013.

[0108] 1-4. Fiber density of glass yarn (per 100m) The obtained glass yarn was unraveled at a speed of 100 m / min, and the number of fibers remaining after passing through a tension bar was counted using a sensor. The count was performed over 1 km, and the number of fibers per 100 m (fibers / 100 m) was calculated.

[0109] 1-5. Weave density of glass cloth The weave density of the warp and weft threads was measured and calculated according to the method specified in "7.9 Density (weave density)" of "General Test Methods for Glass Fibers" in JIS R 3420 2013.

[0110] 1-6. Thickness of glass cloth The thickness of the glass cloth was measured and calculated according to the method specified in "7.10 Thickness of cloth and mat" of "General Test Methods for Glass Fibers" in JIS R 3420 2013.

[0111] 1-7. Mass of glass cloth The mass of the glass cloth was measured and calculated according to the method specified in [7.2 Mass of cloth and mat (mass)] of "General Test Methods for Glass Fibers" in JIS R 3420 2013.

[0112] 1-8. Tensile strength (N / tex) of glass yarn Glass yarn was extracted from the raw material before heat cleaning. The glass yarn was heat-treated under the following heat treatment conditions 1 or 2 and returned to room temperature before being used as a sample for tensile testing. The tensile test was conducted according to the method specified in "7.4 Tensile Strength" of "General Test Methods for Glass Fibers" in JIS R 3420 2013, using an Intesco 2100 tensile testing machine with a gripping distance of 250 mm and a test speed of 250 mm / min, with a sample size of 10 strands. The average value of the tensile strength (N) was calculated and divided by the yarn count of the glass yarn to calculate the tensile strength (N / tex). The heat treatment in the hot air furnace described above was carried out under the following two conditions. • Heat treatment condition 1: Suspended in a hot air furnace at 330°C and heated for 60 minutes. • Heat treatment condition 2: Suspended in a hot air furnace at 400°C for 60 minutes.

[0113] 1-9. Heat cleaning properties of glass cloth If the heat-cleanability is poor, non-volatile organic components will remain after the heat-cleaning process, which will manifest as a discoloration. Therefore, heat-cleanability can be evaluated by the color difference before and after heat-cleaning. To this end, a color inspection was performed on glass cloth before and after heat-cleaning (330°C, 60 minutes). In the color inspection, a colorimeter (Konica Minolta, CR300) was used to determine the color difference (ΔE) using the "CIE1976 (L*a*b*) color difference formula". A color difference (ΔE) of 0 to 0.1 is considered indistinguishable to the naked eye, 0.2 to 0.4 is considered indistinguishable to someone familiar with color inspection, 0.8 to 1.5 is often considered a standard for quality control, and a value of 3.0 or higher is considered to be a level that is likely to lead to complaints due to color differences. Therefore, if the color difference (ΔE) is 1.5 or less, it can be determined that the material has heat-cleanability.

[0114] 2. Materials used in the preparation of the sizing agent for glass long fibers In the examples and comparative examples, the following components were used as the bundling agents for glass long fibers. (1) Acrylic resin emulsion: Manufactured by Go-O Chemical Co., Ltd., trade name GF-6 [25% by mass of non-volatile components; weight loss rate at 330°C in TGA (thermogravimetric analysis) 98% by mass; weight-average molecular weight of acrylic resin 300,000; average particle size (median diameter) of acrylic resin 150 nm; manufactured by heating a mixture of acrylic resin, water, 2-ethylhexyl methacrylate and isobutyl methacrylate as polymerizable monomers, polyoxyethylene polyoxypropylene alkyl ether (trade name Nonion HT-501, NOF Corporation), a polyoxyalkylene alkyl ether type surfactant, and ammonium persulfate as a polymerization initiator] (2) Oil and fat emulsifier A: Manufactured by Matsumoto Oil & Fat Pharmaceutical Co., Ltd., product name KP-2708 (main component is butyl stearate emulsifier, oil and fat content is 50% by mass) (3) Oil and fat emulsifier B: Manufactured by Yoshimura Oil Chemical Co., Ltd., product name Smoother SW45 (paraffin wax emulsifier, paraffin wax content is 30% by mass) (4) Cationized cellulose: O-(2-hydroxy-3-(trimethylammonio)propyl)hydroxyethylcellulose chloride (cationized cellulose: 98% by mass) (5) Polyoxyethylene alkyl ether: Manufactured by Matsumoto Oil & Fat Pharmaceutical Co., Ltd., trade name Marpoteron LE (polyoxyethylene alkyl ether: 30% by mass) (6) N,N,N,N-tetraalkyl quaternary ammonium salt: Manufactured by Toho Chemical Industry Co., Ltd., product name Anstex SAG-25 (N,N,N,N-tetraalkyl quaternary ammonium salt: 25% by mass) (7) Polyoxyethylene alkyl ester: Manufactured by Ipposha Oil & Fat Industry Co., Ltd., trade name Neulan O-6 (polyoxyethylene alkyl ester: 30% by mass) (8) Alkylamide derivative: Manufactured by Matsumoto Oil & Fat Pharmaceutical Co., Ltd., trade name KP-914 (alkylamide derivative: 30% by mass) (9) Polyethylene glycol (average molecular weight 300): Manufactured by Toho Chemical Industry Co., Ltd., product name PEG-300 (10) Polyethylene glycol (average molecular weight 400): Manufactured by Toho Chemical Industry Co., Ltd., product name PEG-400

[0115] 3. Manufacturing of sizing agents for glass long fibers, glass yarn, and glass cloth. [Example 1] (1) Manufacturing of scrubbing agents for glass long fibers The components were mixed to obtain a sizing agent for glass long fibers, as shown below. Note that the parts by mass shown below are the values ​​converted to non-volatile component amounts, except for "water" and "total," and "total" is the sum of volatile and non-volatile components. Acrylic resin emulsion: 75 parts by mass Fat emulsion A: 150 parts by mass Paraffin wax emulsifier: 50 parts by mass Cationic cellulose: 2 parts by mass Alkylamide derivative: 15 parts by mass Water: 9708 parts by mass Total: 10000 parts by mass

[0116] The ratio of the total mass (g) of nonvolatile components to the mass of the glass fiber sizing agent was 2.92% by mass. The composition ratio of the nonvolatile components is shown in Table 1.

[0117] (2) Manufacturing of glass yarn The aforementioned glass fiber sizing agent was applied to multiple glass fibers (E glass, filament diameter 4.1 μm) spun from a spinning furnace using a roll applicator, and the glass fibers were bundled into a single strand. Next, this strand was wound onto a tube without twisting to obtain a cake. The obtained cake was then dried at room temperature. After drying, the strands were unwound from the cake and twisted while being wound onto a bobbin to obtain glass yarn. The obtained glass yarn had 50 filaments, a twist count of 0.5Z, a yarn count of 1.68 tex, and a loss on ignition of 0.25 mass%.

[0118] (3) Manufacturing of glass cloth The obtained glass yarn was used as the weft. Furthermore, the obtained glass yarn was sizingly treated with a secondary sizing agent of the same composition as the glass filament sizing agent used in the production of the glass yarn, followed by beaming. The resulting warp-formed beam was then used as the warp. The warp and weft were set on an air-jet loom, and weaving was carried out in a plain weave structure with a warp density of 95 threads / 25mm and a weft density of 95 threads / 25mm. After weaving, a water jet treatment was performed to open the fibers and obtain a raw cloth. The resulting raw cloth had a loss on ignition of 1.2% by mass, a thickness of 18 μm, and a mass of 12.8 g / m². 2 That was the case.

[0119] The obtained raw cloth was cut to A4 size and subjected to heat cleaning by being suspended in a 330°C hot air oven for 60 minutes to obtain glass cloth. The obtained glass cloth had a loss on ignition of 0.07 mass%, a thickness of 15 μm, and a mass of 12.5 g / m². 2 That was the case.

[0120] [Example 2] (1) Manufacturing of scrubbing agents for glass long fibers The components were mixed to obtain a sizing agent for glass long fibers, as shown below. Note that the parts by mass shown below are the values ​​converted to non-volatile component amounts, except for "water" and "total," and "total" is the sum of volatile and non-volatile components. Acrylic resin emulsion: 75 parts by mass Fat emulsion A: 150 parts by mass Paraffin wax emulsifier: 50 parts by mass Cationic cellulose: 2 parts by mass Alkylamide derivative: 3 parts by mass Water: 9270 parts by mass Total: 10000 parts by mass

[0121] The ratio of the total mass (g) of nonvolatile components to the mass of the glass fiber sizing agent was 2.8% by mass. The composition ratio of the nonvolatile components is shown in Table 1.

[0122] (2) Manufacturing of glass yarn Glass yarn was obtained under the same conditions as in Example 1, except that the aforementioned sizing agent for glass long fibers was used. The obtained glass yarn had 50 filaments, a twist count of 0.5Z, a yarn count of 1.68tex, and a loss on ignition of 0.22% by mass.

[0123] (3) Manufacturing of glass cloth The raw cloth and glass cloth were manufactured under the same conditions as in Example 1, except that the obtained glass yarn was used and a secondary sizing agent for the warp threads with the same composition as the glass filament sizing agent (Example 2) was used.

[0124] The resulting raw cloth had a loss on ignition of 1.2% by mass, a thickness of 18 μm, and a mass of 12.8 g / m². 2 The results were as follows: The ignition loss of the obtained glass cloth was 0.07% by mass, the thickness was 15 μm, and the mass was 12.5 g / m². 2 That was the case.

[0125] [Example 3] (1) Manufacturing of scrubbing agents for glass long fibers The components were mixed to obtain a sizing agent for glass long fibers, as shown below. Note that the parts by mass shown below are the values ​​converted to non-volatile component amounts, except for "water" and "total," and "total" is the sum of volatile and non-volatile components. Acrylic resin emulsion: 75 parts by mass Fat emulsion A: 150 parts by mass Fat emulsion B: 50 parts by mass Polyoxyethylene alkyl ether: 12 parts by mass Alkylamide derivative: 30 parts by mass Water: 9683 parts by mass Total: 10000 parts by mass

[0126] The ratio of the total mass (g) of nonvolatile components to the mass of the glass fiber sizing agent was 3.17% by mass. The composition ratio of the nonvolatile components is shown in Table 1.

[0127] (2) Manufacturing of glass yarn Glass yarn was obtained under the same conditions as in Example 1, except that the aforementioned glass filament sizing agent was used. The obtained glass yarn had 50 filaments, a twist count of 0.5Z, a yarn count of 1.68 tex, and a loss on ignition of 0.38 mass%.

[0128] (3) Manufacturing of glass cloth Except for using the obtained glass yarn and using a secondary sizing agent for the warp threads with the same composition as the glass filament sizing agent (Example 3), the raw cloth and glass cloth were manufactured under the same conditions as in Example 1.

[0129] The resulting raw cloth had a loss on ignition of 1.0% by mass, a thickness of 18 μm, and a mass of 12.8 g / m². 2 The results were as follows: The ignition loss of the obtained glass cloth was 0.08% by mass, the thickness was 15 μm, and the mass was 12.5 g / m². 2 That was the case.

[0130] [Example 4] (1) Manufacturing of scrubbing agents for glass long fibers The components were mixed to obtain a sizing agent for glass long fibers, as shown below. Note that the parts by mass shown below are the values ​​converted to non-volatile component amounts, except for "water" and "total," and "total" is the sum of volatile and non-volatile components. Acrylic resin emulsion: 75 parts by mass Fat emulsion A: 150 parts by mass Fat emulsion B: 50 parts by mass Polyoxyethylene alkyl ether: 12 parts by mass Alkylamide derivative: 15 parts by mass Water: 9698 parts by mass Total: 10000 parts by mass

[0131] The ratio of the total mass (g) of nonvolatile components to the mass of the glass fiber sizing agent was 3.02% by mass. The composition ratio of the nonvolatile components is shown in Table 1.

[0132] (2) Manufacturing of glass yarn Glass yarn was obtained under the same conditions as in Example 1, except that the aforementioned sizing agent for glass long fibers was used. The obtained glass yarn had 50 filaments, a twist count of 0.5Z, a yarn count of 1.68tex, and an ignition loss of 0.44 mass%. Furthermore, the ignition loss of the glass yarn after heat treatment under heat treatment condition 1 was 0.04 mass%.

[0133] (3) Manufacturing of glass cloth The raw cloth and glass cloth were manufactured under the same conditions as in Example 1, except that the obtained glass yarn was used and a secondary sizing agent for the warp threads with the same composition as the glass filament sizing agent (Example 4) was used.

[0134] The resulting raw cloth had a loss on ignition of 1.0% by mass, a thickness of 18 μm, and a mass of 12.8 g / m². 2 The results were as follows: The ignition loss of the obtained glass cloth was 0.06% by mass, the thickness was 15 μm, and the mass was 12.5 g / m². 2 That was the case.

[0135] [Example 5] (1) Manufacturing of scrubbing agents for glass long fibers The components were mixed to obtain a sizing agent for glass long fibers, as shown below. Note that the parts by mass shown below are the values ​​converted to non-volatile component amounts, except for "water" and "total," and "total" is the sum of volatile and non-volatile components. Acrylic resin emulsion: 75 parts by mass Fat emulsion A: 150 parts by mass Fat emulsion B: 50 parts by mass Polyoxyethylene alkyl ether: 12 parts by mass Alkylamide derivative: 15 parts by mass Polyethylene glycol (average molecular weight 300): 75 parts by mass Water: 9623 parts by mass Total: 10000 parts by mass

[0136] The ratio of the total mass (g) of nonvolatile components to the mass of the glass fiber sizing agent was 3.77% by mass. The composition ratio of the nonvolatile components is shown in Table 1.

[0137] (2) Manufacturing of glass yarn Glass yarn was obtained under the same conditions as in Example 1, except that the aforementioned sizing agent for glass long fibers was used. The obtained glass yarn had 50 filaments, a twist count of 0.5Z, a yarn count of 1.68 tex, and an ignition loss of 0.49 mass%. Furthermore, the ignition loss of the glass yarn after heat treatment under heat treatment condition 1 was 0.04 mass%.

[0138] (3) Manufacturing of glass cloth The raw cloth and glass cloth were manufactured under the same conditions as in Example 1, except that the obtained glass yarn was used and a secondary sizing agent for the warp threads with the same composition as the glass filament sizing agent (Example 5) was used.

[0139] The resulting raw cloth had a loss on ignition of 0.9% by mass, a thickness of 18 μm, and a mass of 12.8 g / m². 2 The results were as follows: The ignition loss of the obtained glass cloth was 0.09% by mass, the thickness was 15 μm, and the mass was 12.5 g / m². 2 That was the case.

[0140] [Example 6] (1) Manufacturing of scrubbing agents for glass long fibers The components were mixed to obtain a sizing agent for glass long fibers, as shown below. Note that the parts by mass shown below are the values ​​converted to non-volatile component amounts, except for "water" and "total," and "total" is the sum of volatile and non-volatile components. Acrylic resin emulsion: 75 parts by mass Fat emulsion A: 150 parts by mass Fat emulsion B: 50 parts by mass Polyoxyethylene alkyl ether: 12 parts by mass Alkylamide derivative: 15 parts by mass Polyethylene glycol (average molecular weight 400): 75 parts by mass Water: 9623 parts by mass Total: 10000 parts by mass

[0141] The ratio of the total mass (g) of nonvolatile components to the mass of the glass fiber sizing agent was 3.77% by mass. The composition ratio of the nonvolatile components is shown in Table 1.

[0142] (2) Manufacturing of glass yarn Glass yarn was obtained under the same conditions as in Example 1, except that the aforementioned sizing agent for glass long fibers was used. The obtained glass yarn had 50 filaments, a twist count of 0.5Z, a yarn count of 1.68 tex, and an ignition loss of 0.40 mass%. Furthermore, the ignition loss of the glass yarn after heat treatment under heat treatment condition 1 was 0.04 mass%.

[0143] (3) Manufacturing of glass cloth The raw cloth and glass cloth were manufactured under the same conditions as in Example 1, except that the obtained glass yarn was used and a secondary sizing agent for the warp threads with the same composition as the glass filament sizing agent (Example 6) was used.

[0144] The resulting raw cloth had a loss on ignition of 1.0% by mass, a thickness of 18 μm, and a mass of 12.8 g / m². 2The results were as follows: The ignition loss of the obtained glass cloth was 0.09% by mass, the thickness was 15 μm, and the mass was 12.5 g / m². 2 That was the case.

[0145] [Comparative Example 1] (1) Manufacturing of scrubbing agents for glass long fibers The components were mixed to obtain a sizing agent for glass long fibers, as shown below. Note that the parts by mass shown below are the values ​​converted to non-volatile component amounts, except for "water" and "total," and "total" is the sum of volatile and non-volatile components. Acrylic resin emulsion: 75 parts by mass Fat emulsion A: 150 parts by mass Fat emulsion B: 50 parts by mass N,N,N,N-tetraalkylquaternary ammonium salt: 12 parts by mass Alkylamide derivative: 30 parts by mass Water: 9683 parts by mass Total: 10000 parts by mass

[0146] The ratio of the total mass (g) of nonvolatile components to the mass of the glass fiber sizing agent was 3.17% by mass. The composition ratio of the nonvolatile components is shown in Table 1.

[0147] (2) Manufacturing of glass yarn Glass yarn was obtained under the same conditions as in Example 1, except that the aforementioned sizing agent for glass long fibers was used. The obtained glass yarn had 50 filaments, a twist count of 0.5Z, a yarn count of 1.68tex, and a loss on ignition of 0.35% by mass.

[0148] (3) Manufacturing of glass cloth Except for using the obtained glass yarn and using a secondary sizing agent for the warp threads with the same composition as the glass filament sizing agent (Comparative Example 1), the raw cloth and glass cloth were manufactured under the same conditions as in Example 1.

[0149] The resulting raw cloth had a loss on ignition of 1.1% by mass, a thickness of 18 μm, and a mass of 12.8 g / m². 2The results were as follows: The ignition loss of the obtained glass cloth was 0.13% by mass, the thickness was 15 μm, and the mass was 12.5 g / m². 2 That was the case.

[0150] [Comparative Example 2] (1) Manufacturing of scrubbing agents for glass long fibers The components were mixed to obtain a sizing agent for glass long fibers, as shown below. Note that the parts by mass shown below are the values ​​converted to non-volatile component amounts, except for "water" and "total," and "total" is the sum of volatile and non-volatile components. Fat emulsion A: 150 parts by mass Fat emulsion B: 50 parts by mass Cationic cellulose: 2 parts by mass Alkylamide derivative: 30 parts by mass Water: 9768 parts by mass Total: 10000 parts by mass

[0151] The ratio of the total mass (g) of nonvolatile components to the mass of the glass fiber sizing agent was 2.32% by mass. The composition ratio of the nonvolatile components is shown in Table 1.

[0152] (2) Manufacturing of glass yarn Glass yarn was obtained under the same conditions as in Example 1, except that the aforementioned sizing agent for glass long fibers was used. The obtained glass yarn had 50 filaments, a twist count of 0.5Z, a yarn count of 1.68tex, and a loss on ignition of 0.19% by mass.

[0153] (3) Manufacturing of glass cloth Except for using the obtained glass yarn and using a secondary sizing agent for the warp threads with the same composition as the glass filament sizing agent (Comparative Example 2), the raw cloth and glass cloth were manufactured under the same conditions as in Example 1.

[0154] The resulting raw cloth had a loss on ignition of 1.2% by mass, a thickness of 18 μm, and a mass of 12.8 g / m². 2 The results were as follows: The ignition loss of the obtained glass cloth was 0.13% by mass, the thickness was 15 μm, and the mass was 12.5 g / m². 2That was the case.

[0155] [Comparative Example 3] (1) Manufacturing of scrubbing agents for glass long fibers The components were mixed to obtain a sizing agent for glass long fibers, as shown below. Note that the parts by mass shown below are the values ​​converted to non-volatile component amounts, except for "water" and "total," and "total" is the sum of volatile and non-volatile components. Acrylic resin emulsion: 75 parts by mass Fat emulsion A: 150 parts by mass Fat emulsion B: 50 parts by mass Alkylamide derivative: 30 parts by mass Water: 9695 parts by mass Total: 10000 parts by mass

[0156] The ratio of the total mass (g) of nonvolatile components to the mass of the glass fiber sizing agent was 3.05% by mass. The composition ratio of the nonvolatile components is shown in Table 1.

[0157] (2) Manufacturing of glass yarn Glass yarn was obtained under the same conditions as in Example 1, except that the aforementioned glass filament sizing agent was used. The obtained glass yarn had 50 filaments, a twist count of 0.5Z, a yarn count of 1.68tex, and a loss on ignition of 0.29% by mass.

[0158] (3) Manufacturing of glass cloth Except for using the obtained glass yarn and using a secondary sizing agent for the warp threads with the same composition as the glass filament sizing agent (Comparative Example 3), the raw cloth and glass cloth were manufactured under the same conditions as in Example 1.

[0159] The resulting raw cloth had a loss on ignition of 1.1% by mass, a thickness of 18 μm, and a mass of 12.8 g / m². 2 The results were as follows: The ignition loss of the obtained glass cloth was 0.15% by mass, the thickness was 15 μm, and the mass was 12.5 g / m². 2 That was the case.

[0160] [Comparative Example 4] (1) Manufacturing of scrubbing agents for glass long fibers The components were mixed to obtain a sizing agent for glass long fibers, as shown below. Note that the parts by mass shown below are the values ​​converted to non-volatile component amounts, except for "water" and "total," and "total" is the sum of volatile and non-volatile components. Acrylic resin emulsion: 75 parts by mass Fat emulsion A: 150 parts by mass Fat emulsion B: 50 parts by mass Polyoxyethylene alkyl ester: 15 parts by mass Alkylamide derivative: 30 parts by mass Water: 9680 parts by mass Total: 10000 parts by mass

[0161] The ratio of the total mass (g) of nonvolatile components to the mass of the glass fiber sizing agent was 3.2% by mass. The composition ratio of the nonvolatile components is shown in Table 1.

[0162] (2) Manufacturing of glass yarn Glass yarn was obtained under the same conditions as in Example 1, except that the aforementioned glass filament sizing agent was used. The obtained glass yarn had 50 filaments, a twist count of 0.5Z, a yarn count of 1.68 tex, and a loss on ignition of 0.31% by mass.

[0163] (3) Manufacturing of glass cloth Except for using the obtained glass yarn and using a secondary sizing agent for the warp threads with the same composition as the glass filament sizing agent (Comparative Example 4), the raw cloth and glass cloth were manufactured under the same conditions as in Example 1.

[0164] The resulting raw cloth had a loss on ignition of 1.1% by mass, a thickness of 18 μm, and a mass of 12.8 g / m². 2 The results were as follows: The ignition loss of the obtained glass cloth was 0.21% by mass, the thickness was 15 μm, and the mass was 12.5 g / m². 2 That was the case.

[0165] [Comparative Example 5] (1) Preparation of glass yarn A glass yarn (product name BC3000 1 / 0 0.5Z X-4, manufactured by Unitika Glass Fiber Co., Ltd.) with a starch coating was prepared. The glass fibers constituting this glass yarn were made of E-glass, and their filament diameter was 4.1 μm. The glass yarn had 50 filaments, a twist count of 0.5Z, a yarn count of 1.68 tex, and an ignition loss of 1.00 mass%. Furthermore, the ignition loss of the glass yarn after heat treatment under heat treatment condition 1 was 0.16 mass%.

[0166] (2) Manufacturing of glass cloth Except for using the aforementioned glass yarn and using a secondary sizing agent for the warp threads that mainly consists of polyvinyl alcohol, the raw cloth and glass cloth were manufactured under the same conditions as in Example 1.

[0167] The resulting raw cloth had a loss on ignition of 2.4% by mass, a thickness of 18 μm, and a mass of 12.8 g / m². 2 The results were as follows: The ignition loss of the obtained glass cloth was 0.77% by mass, the thickness was 15 μm, and the mass was 12.5 g / m². 2 That was the case.

[0168] 4. Evaluation Results Table 1 shows the results of measuring the physical properties of the glass yarn and glass cloth obtained in Examples 1-6 and Comparative Examples 1-5.

[0169] [Table 1]

[0170] In Examples 1-6, the use of a glass fiber scrubber containing acrylic resin, oil, and cationized cellulose or polyoxyethylene alkyl ether resulted in excellent suppression of fluff generation, making it suitable for the production of thin glass cloth for printed circuit boards. Furthermore, Examples 1-6 exhibited excellent heat cleaning properties at temperatures below 400°C, and even when the resulting glass yarn was manufactured using a heat cleaning treatment at temperatures below 400°C, the occurrence of discoloration (burnt color) caused by insufficient heat cleaning was sufficiently suppressed.

[0171] In particular, in Examples 1 and 4-6, the lint suppression effect was significantly improved by using a glass fiber scrubbing agent in which the ratio of the total mass of nonvolatile components of the softener component to the total mass of nonvolatile components (g / L) was 3-6% by mass. Especially in Examples 4-6, the lint suppression effect was significantly improved by using a glass fiber scrubbing agent containing acrylic resin, oil and fat, and polyoxyethylene alkyl ether, in which the ratio of the total mass of nonvolatile components of the softener component to the total mass of nonvolatile components (g / L) was 3-6% by mass, and the heat cleaning performance at temperatures below 400°C was also significantly improved.

[0172] On the other hand, in Comparative Example 1, a sizing agent for glass long fibers that does not contain cationized cellulose or polyoxyethylene alkyl ether was used, and when heat cleaning treatment was performed at temperatures below 400°C, discoloration (burning) occurred in the glass cloth, indicating poor heat cleaning performance at temperatures below 400°C.

[0173] Comparative Example 2 used a glass fiber scrubber that did not contain acrylic resin, resulting in insufficient lint suppression and making it unsuitable for manufacturing thin glass cloth for printed circuit boards. Furthermore, Comparative Example 2 also exhibited poor heat cleaning properties at temperatures below 400°C.

[0174] Comparative Example 3 used a glass fiber scrubber containing acrylic resin and oils, but without cationized cellulose or polyoxyethylene alkyl ether. As a result, it had insufficient lint suppression and was unsuitable for the production of thin glass cloth for printed circuit boards. Furthermore, Comparative Example 3 also exhibited poor heat cleaning properties at temperatures below 400°C.

[0175] Comparative Example 4 used a scrubbing agent for glass long fibers containing acrylic resin, oils and fats, and polyoxyethylene alkylsters, and exhibited poor heat cleaning performance under temperature conditions of 400°C or below.

[0176] Comparative Example 5 used starch alone as a film-forming component for a sizing agent for glass long fibers, and exhibited poor heat cleaning performance at temperatures below 400°C.

Claims

1. A glass cloth formed from glass yarn made by bundling long glass fibers, The glass material constituting the long glass fibers is E-glass or a glass composition having a relative permittivity of less than 5.0 at a frequency of 1 MHz. The tensile strength of the glass yarn is 0.50 N / tex or more, and The ignition loss of the glass cloth is 0.10% by mass or less. Glass cloth, wherein the aforementioned glass cloth has undergone heat cleaning treatment.

2. The glass cloth according to claim 1, used as a component material for a printed circuit board.

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