Surface-treated glass cloth, prepreg and printed wiring board

Abstract

Provided is a surface-treated glass cloth which is capable of providing excellent adhesion to a matrix resin and in which, even when the adhered amount of a surface-treated layer increases, the impregnability of the matrix resin with respect to glass fibers is not impaired and excessive hardening of texture does not occur. [Solution] The present invention is a surface-treated glass cloth comprising a surface-treated layer on a surface thereof, wherein the surface-treated layer contains a silane coupling agent and a surface-treating resin, the surface-treating resin includes a structural unit derived from a styrene monomer, and the integral of the peak of protons attributed to a benzene ring measured by 1H-NMR is in the range of 28-46% of the integral of all the proton peaks.

Description

Surface-treated glass cloth, prepreg and printed wiring board

[0001] The present invention relates to a surface-treated glass cloth, a prepreg, and a printed wiring board.

[0002] In recent years, with the development of communication technology, frequencies used in communication have been increasing into the GHz band. However, the higher the frequency, the greater the influence of the dielectric constant and dielectric loss tangent of the materials used in printed wiring boards, resulting in greater signal attenuation due to dielectric loss.

[0003] Therefore, in the field of communication technology, in order to reduce the dielectric loss of high-frequency signals, a prepreg is used in which a glass cloth having a low dielectric constant and a low dielectric dissipation factor is impregnated with a matrix resin having a low dielectric constant and a low dielectric dissipation factor. However, the prepreg has a problem in that the adhesion between the glass cloth having a low dielectric constant and a low dielectric dissipation factor and the matrix resin having a low dielectric constant and a low dielectric dissipation factor is poor, resulting in a decrease in insulation reliability, etc.

[0004] In order to improve the affinity with the matrix resin and obtain excellent adhesiveness, glass cloth is usually provided with a surface treatment layer containing a silane coupling agent on its surface. For example, a surface-treated glass cloth is known, which has a surface treatment layer containing a silane coupling agent and a surface treatment resin having a functional group capable of forming a chemical bond with the matrix resin on the surface of the glass cloth (see, for example, Patent Document 1).

[0005] According to the surface-treated glass cloth described in Patent Document 1, by providing a surface treatment layer on the surface of the glass cloth, which contains the silane coupling agent and the surface treatment resin having a functional group capable of forming a chemical bond with the matrix resin, it is possible to obtain a printed wiring board in which the occurrence of cracks during machining and the decrease in solder heat resistance are suppressed.

[0006] Patent No. 3897699

[0007] However, while increasing the amount of the surface treatment layer applied to the glass cloth improves the adhesion to the matrix resin, it also makes it difficult for the matrix resin to penetrate between the glass filaments of the glass fibers constituting the glass cloth, which can cause defects such as striation voids, and the texture of the obtained surface-treated glass cloth becomes excessively hard, causing wrinkles during the production of prepregs and worsening processability.

[0008] The stria voids refer to a state in which, when the impregnation of the glass fibers constituting the glass cloth with the matrix resin is low, the matrix resin hardens before flowing into the gaps between the glass filaments of the glass fibers, resulting in the formation of voids without the matrix resin impregnating the gaps between the glass filaments. For example, if the stria voids exist in a prepreg, when a printed wiring board is manufactured using the prepreg, the metal constituting the wiring or via undergoes ion migration at the interface between the glass fibers and the matrix resin, causing a short circuit due to a CAF (Conductive Anodic Filament) or the like, thereby reducing the insulation reliability of the printed wiring board.

[0009] Therefore, an object of the present invention is to provide a surface-treated glass cloth which overcomes the above-mentioned disadvantages, has excellent adhesion to a matrix resin, does not impregnate the glass fibers with a matrix resin even when the amount of the surface treatment layer attached is increased, and does not cause the texture to become excessively hard.

[0010] In order to achieve the above object, the present invention provides a surface-treated glass cloth having a surface treatment layer on a surface thereof, the surface treatment layer containing a silane coupling agent and a surface treatment resin, the surface treatment resin containing a structural unit derived from a styrene-based monomer, １ The integral value of the peak of a proton attributed to a benzene ring measured by H-NMR is in the range of 28 to 46% of the integral value of the peaks of all protons.

[0011] The surface-treated glass cloth of the present invention has a surface treatment layer containing the silane coupling agent and the surface treatment resin, thereby achieving excellent adhesion between the surface treatment layer and the matrix resin, and even if the amount of adhesion of the surface treatment layer is increased, the impregnation of the glass fiber with the matrix resin is not impaired, and the texture does not become excessively hard. As a result, the surface-treated glass cloth of the present invention can produce a prepreg with excellent insulation reliability without generating defects such as striae voids, and can achieve excellent processability when producing the prepreg.

[0012] The phrase "increasing the amount of adhesion of the surface treatment layer" means that the amount of adhesion of the surface treatment layer is 0.8 mass % or more based on the total amount of the surface-treated glass cloth.

[0013] The surface treatment resin contained in the surface treatment layer is １ When the integral value of the peak of the protons assigned to the benzene ring measured by H-NMR is less than 28% of the integral value of the peaks of all protons, the texture of the surface-treated glass cloth of the present invention becomes hard, and the impregnation of the matrix resin into the glass fibers of the surface-treated glass cloth decreases. １ If the integral value of the peaks of protons assigned to the benzene ring measured by H-NMR exceeds 46% of the integral value of all proton peaks, the impregnation of the matrix resin into the glass fibers of the surface-treated glass cloth of the present invention will be reduced.

[0014] In the surface-treated glass cloth of the present invention, the silane coupling agent contained in the surface treatment layer is not particularly limited, but when a radical-polymerizable thermosetting resin is used as the matrix resin, it is preferably a methacrylic silane from the viewpoint of excellent adhesion to the radical-polymerizable thermosetting resin. Examples of the radical-polymerizable thermosetting resin used as the matrix resin include polyphenylene ether, LCP, cycloolefin polymer, divinylbenzene resin, and maleimide resin.

[0015] In the surface-treated glass cloth of the present invention, the styrene-based monomer is preferably one or more monomers selected from styrene-based monomers represented by the following general formula (1):

[0016] [In the formula, R １ is hydrogen or an alkyl group having 1 to 2 carbon atoms, R ２ ~R ６ are each independently a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, or an aryl group, and may contain a heteroatom.

[0017] Specific examples of the styrene-based monomer include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, 4-tert-butylstyrene, o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene, o-ethoxystyrene, m-ethoxystyrene, p-ethoxystyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, o-bromostyrene, m-bromostyrene, p-bromostyrene, o-fluorostyrene, m-fluorostyrene, p-fluorostyrene, o-chloromethylstyrene, m-chloromethylstyrene, and p-chloromethylstyrene. Of these, styrene is preferred.

[0018] In the surface-treated glass cloth of the present invention, the surface treatment layer may be a single layer consisting of a mixture of the silane coupling agent and the surface treatment resin. However, from the viewpoints that the silane coupling agent has excellent reactivity with glass and the surface treatment resin has excellent reactivity with the matrix resin, it is preferable that the surface treatment layer consists of a first surface treatment layer containing the silane coupling agent and a second surface treatment layer containing the surface treatment resin.

[0019] In the surface-treated glass cloth of the present invention, the amount of the surface treatment layer deposited is preferably in the range of 0.8 to 5.0 mass % based on the total amount of the surface-treated glass cloth. If the amount of the surface treatment layer deposited is less than 0.8 mass % based on the total amount of the surface-treated glass cloth, the adhesion to the matrix resin may be insufficient, whereas if it exceeds 5.0 mass %, the surface-treated glass cloth may not be stably produced.

[0020] The surface-treated glass cloth of the present invention preferably has a dielectric loss tangent in the range of 0.0001 to 0.0040 at a measurement frequency of 10 GHz. It is technically difficult to make the dielectric loss tangent of the surface-treated glass cloth of the present invention less than 0.0001, and if the dielectric loss tangent exceeds 0.0040, when the surface-treated glass cloth is made into a prepreg or a printed wiring board, the dielectric loss of high-frequency signals may not be sufficiently reduced.

[0021] The prepreg and printed wiring board of the present invention are characterized by including the surface-treated glass cloth of the present invention.

[0022] Next, the embodiment of the present invention will be described in more detail.

[0023] The surface-treated glass cloth of this embodiment is, for example, a surface-treated glass cloth having a low dielectric constant and a low dielectric loss tangent and provided with a surface treatment layer on the surface thereof, the surface treatment layer containing a silane coupling agent and a surface treatment resin, the surface treatment resin containing a structural unit derived from a styrene-based monomer, １ The integral value of the proton peaks assigned to the benzene ring measured by H-NMR is in the range of 28 to 46% of the integral value of all proton peaks.

[0024] The glass cloth having a low dielectric constant and a low dielectric loss tangent is a glass fiber fabric woven using glass fiber yarns having a glass composition having a low dielectric constant and a low dielectric loss tangent as warp and weft yarns. Examples of the glass composition having a low dielectric constant and a low dielectric loss tangent include silica glass, D glass, NE glass, and L glass. The glass composition may, for example, contain 48.0 to 62.0 mass % of SiO2 relative to the total amount of glass fibers. ２and B in the range of 17.0 to 26.0 mass% ２ O ３ and Al in the range of 9.0 to 18.0 mass% ２ O ３ 0.1 to 9.0 mass% of CaO, 0 to 6.0 mass% of MgO, and 0.05 to 0.5 mass% of Na in total. ２ O.K. ２ O and Li ２ O and TiO in the range of 0 to 5.0 mass% ２ and SrO in the range of 0 to 6.0 mass %, and F in the range of 0 to 3.0 mass % in total. ２ and Cl ２ and P in the range of 0 to 6.0 mass% ２ O ５ Examples of the composition include:

[0025] The silane coupling agent constituting the surface treatment layer is not particularly limited, and examples thereof include aminosilane, chlorosilane, epoxysilane, mercaptosilane, vinylsilane, (meth)acrylicsilane, cationic silane, etc., but is preferably methacrylsilane or cationic silane, and more preferably methacrylsilane. Examples of the methacrylsilane include 3-methacryloxypropyltrimethoxysilane, and examples of the cationic silane include N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride and N-phenyl-3-aminopropyltrimethoxysilane hydrochloride.

[0026] It is preferable that the surface treatment resin constituting the surface treatment layer contains a structural unit derived from a styrene-based monomer, and the styrene-based monomer is one or more monomers selected from styrene-based monomers represented by the following general formula (1):

[0027] [In the formula, R １ is hydrogen or an alkyl group having 1 to 2 carbon atoms, R ２ ~R ６ are each independently a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, or an aryl group, and may contain a heteroatom.

[0028] Examples of the styrene-based monomer include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, 4-tert-butylstyrene, o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, o-methoxystyrene, m-methoxystyrene, p-methoxystyrene, o-ethoxystyrene, m-ethoxystyrene, p-ethoxystyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, o-bromostyrene, m-bromostyrene, p-bromostyrene, o-fluorostyrene, m-fluorostyrene, p-fluorostyrene, o-chloromethylstyrene, m-chloromethylstyrene, and p-chloromethylstyrene.

[0029] The surface treatment resin constituting the surface treatment layer may contain structural units derived from a styrene-based monomer as well as structural units derived from another polymerizable monomer. The other polymerizable monomer is not particularly limited, but is preferably a (meth)acrylic acid ester-based monomer.

[0030] As the (meth)acrylic acid ester-based monomer, for example, one or more of (meth)acrylic acid alkyl esters, (meth)acrylic acid hydroxyalkyl esters, (meth)acrylic acid alkoxyalkyl esters, (meth)acrylic acid aralkyl esters, and (meth)acrylic acid aryl esters can be used, but it is preferable to use (meth)acrylic acid alkyl esters.

[0031] Examples of the alkyl (meth)acrylate include alkyl (meth)acrylates having a linear or branched alkyl group, and alicyclic alkyl (meth)acrylates.

[0032] Examples of the (meth)acrylic acid alkyl ester having a linear or branched alkyl group include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, sec-butyl (meth)acrylate, n-amyl (meth)acrylate, isoamyl (meth)acrylate, n-hexyl (meth)acrylate, and n-octyl (meth)acrylate. acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-undecyl (meth)acrylate, n-dodecyl (meth)acrylate, n-tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, and behenyl (meth)acrylate.

[0033] Examples of the alicyclic (meth)acrylic acid alkyl ester include cyclohexyl (meth)acrylate, 4-tert-butylcyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and dicyclopentenyl (meth)acrylate.

[0034] The other resin component can be one or more of the above-mentioned (meth)acrylic acid alkyl esters, and is preferably a (meth)acrylic acid alkyl ester having a linear or branched alkyl group having 1 to 18 carbon atoms, more preferably 1 to 12. Examples of the (meth)acrylic acid alkyl ester include methyl (meth)acrylate and 2-ethylhexyl (meth)acrylate.

[0035] The surface treatment resin is preferably an emulsion resin of a polymer of the styrene-based monomer and another polymerizable monomer, such as an emulsion resin obtained by mixing one or more of the emulsion resins of the styrene-based monomer and another polymerizable monomer, or an emulsion resin obtained by mixing a styrene resin and an acrylic resin.

[0036] The emulsion resin can be obtained by polymerizing one or more polymerizable monomer components that form resin particles in an aqueous medium such as water that is normally contained in the emulsion resin. Alternatively, the emulsion resin can be obtained by post-emulsifying resin particles produced separately from the aqueous medium by a method such as forced emulsification or self-emulsification. However, it is preferable that the emulsion resin is obtained by emulsion polymerization of polymerizable monomer components that form resin particles in an aqueous medium.

[0037] The aqueous medium is preferably water, and water alone or a mixture of water and an organic solvent may be used. Examples of the organic solvent include, but are not limited to, methanol, ethanol, isopropanol, ethyl carbitol, and N-methylpyrrolidone. One or more of the organic solvents may be used. The resin constituting the emulsion resin preferably has a glass transition temperature in the range of 20 to 60°C, more preferably 25 to 55°C, so that the resin can be uniformly applied to the surface of the glass fiber in the step of forming a surface treatment layer on the glass cloth (described later) and the emulsion resin can be uniformly spread.

[0038] The surface treatment resin is １Since the integral value of the peak of the protons assigned to the benzene ring measured by H-NMR is in the range of 28 to 46% of the integral value of the peaks of all protons, when a surface treatment layer is formed on the surface of the surface-treated glass cloth of this embodiment together with the silane coupling agent, excellent adhesion can be obtained between the glass fiber and the matrix resin, and even if the adhesion amount of the surface treatment layer is increased, the impregnation of the matrix resin into the glass fiber of the surface-treated glass cloth is not impaired. Furthermore, the texture of the surface-treated glass cloth does not become too hard, so that excellent processability can be obtained when producing a prepreg.

[0039] The surface treatment resin is １ When the integral value of the peak of the protons assigned to the benzene ring measured by H-NMR is less than 28% of the integral value of the peaks of all protons, when a surface treatment layer is formed on the surface of the surface-treated glass cloth of this embodiment together with the silane coupling agent, the texture of the surface-treated glass cloth becomes hard and the impregnation of the matrix resin into the glass fibers of the surface-treated glass cloth decreases. １ When the integral value of the peaks of protons assigned to the benzene ring measured by H-NMR exceeds 46% of the integral value of the peaks of all protons, when a surface treatment layer is formed on the surface of the surface-treated glass cloth of the present embodiment together with the silane coupling agent, the impregnation of the matrix resin into the glass fibers of the surface-treated glass cloth decreases.

[0040] The aforementioned １ The H-NMR measurement is carried out using, for example, a nuclear magnetic resonance analyzer manufactured by OXFORD INSTRUMENTS (trade name: Pulsar HFC) in chloroform-D1 (CDCl) containing tetramethylsilane (TMS) as an internal standard. ３ ) is used as a solvent, and the surface treatment resin is dissolved in the solvent at a concentration in the range of 0.1 to 10 mass % to prepare a solution as a sample. １From the results of the H-NMR measurement, the peaks in the range of 6.3 to 7.2 ppm in chemical shift δ relative to the peak of the internal standard were determined to be peaks of protons belonging to the benzene ring, and the peaks of the internal standard and the peaks of chloroform (CHCl 3 ) contained in small amounts in chloroform-D1 were determined to be peaks of protons belonging to the benzene ring. ３ The ratio of the integral value of the peaks of protons attributable to the benzene ring to the integral value of the peaks of all protons excluding the peaks of the protons attributable to the benzene ring is calculated.

[0041] In the surface-treated glass cloth of this embodiment, the surface treatment layer may be a single layer consisting of a mixture of the silane coupling agent and the surface treatment resin. However, from the viewpoint that the silane coupling agent has excellent reactivity with glass and the surface treatment resin has excellent reactivity with a matrix resin, it is preferable that the surface treatment layer consists of a first surface treatment layer containing the silane coupling agent and a second surface treatment layer containing the surface treatment resin.

[0042] The amount of the surface treatment layer on the glass cloth is preferably in the range of 0.8 to 5.0 mass% relative to the total amount of the surface-treated glass cloth. If the amount of the surface treatment layer is less than 0.8 mass% relative to the total amount of the surface-treated glass cloth, the adhesion to the matrix resin may be insufficient, while if it exceeds 5.0 mass%, the surface-treated glass cloth may not be stably produced. From the viewpoints of adhesion to the matrix resin and production stability, the amount of the surface treatment layer is more preferably in the range of 1.0 to 3.0 mass%, and even more preferably in the range of 1.2 to 2.0 mass%.

[0043] Furthermore, the surface-treated glass cloth of this embodiment preferably has a dielectric loss tangent in the range of 0.0001 to 0.0040 at a measurement frequency of 10 GHz. It is technically difficult to make the surface-treated glass cloth of this embodiment have a dielectric loss tangent of less than 0.0001, and if the dielectric loss tangent exceeds 0.0040, when the surface-treated glass cloth is made into a prepreg or a printed wiring board, the dielectric loss of high-frequency signals may not be sufficiently reduced. From the viewpoint of productivity and processability of the glass fiber, the dielectric loss tangent is more preferably in the range of 0.0008 to 0.0030.

[0044] The surface-treated glass cloth of this embodiment can be produced, for example, as follows.

[0045] First, glass raw materials prepared to obtain a glass composition for glass fiber having a predetermined glass composition are melted in a glass melting furnace to obtain molten glass (a melt of the glass composition for glass fiber). The glass composition can be, for example, the glass composition having a low dielectric constant and a low dielectric loss tangent.

[0046] The content of each component of the glass composition can be measured using an ICP optical emission spectrometer for the light element Li, and using a wavelength dispersive X-ray fluorescence analyzer for the other elements. Specifically, the content of each component of the glass composition can be measured as follows.

[0047] First, glass fibers are cut to an appropriate size, placed in a platinum crucible, and melted in an electric furnace at 1550°C for 6 hours while stirring, to obtain a homogeneous molten glass. If organic matter is attached to the surface of the glass fibers or if the glass fibers are contained in an organic material (resin) mainly as a reinforcing material, the glass fibers are used after removing the organic matter by, for example, heating in a muffle furnace at 300 to 650°C for 2 to 24 hours.

[0048] Next, the obtained molten glass is poured onto a carbon plate to produce glass cullet, which is then crushed and powdered to produce glass powder. The light element Li is quantitatively analyzed using an ICP optical emission spectrometer after the glass powder is thermally decomposed with acid. The other elements are quantitatively analyzed using a wavelength dispersive X-ray fluorescence analyzer after the glass powder is molded into a disk shape using a press. The results of these quantitative analyses are converted into oxides to calculate the content and total amount of each component, and the content (mass %) of each of the aforementioned components can be determined from these values.

[0049] The molten glass is then discharged from a vessel (bushing) having a nozzle plate with several to several thousand nozzle tips formed thereon, and is cooled and solidified while being stretched by being wound up at high speed, thereby forming a glass filament (this operation is sometimes called "spinning"). The bushing is made of a noble metal such as platinum.

[0050] Here, the glass filament discharged from one nozzle tip or hole and cooled and solidified usually has a true circular cross-sectional shape and a diameter of 3.0 to 10 μm. On the other hand, when the nozzle tip has a non-circular shape and has a protrusion or notch that quenches the molten glass, it is possible to obtain a glass filament having a non-circular (e.g., elliptical or oval) cross-sectional shape by controlling the temperature conditions.

[0051] Next, 20 to 300 of the glass filaments formed as described above are bundled by applying a sizing agent (sometimes referred to as a primary sizing agent) with an applicator, and then wound around a collet to form a glass strand (glass fiber bundle).

[0052] Next, the formed glass strands are used as warp glass strands and weft glass strands, and a glass cloth can be obtained by weaving the warp glass strands and the weft glass strands as warp and weft. The weaving can be carried out using a loom known per se, such as a jet loom (e.g., an air jet or water jet loom), a shuttle loom, or a rapier loom. The weaving method used on the loom can be, for example, a plain weave, a satin weave, a tango weave, or a twill weave, with plain weave being preferred from the viewpoint of production efficiency.

[0053] Next, the glass cloth is subjected to a deoiling treatment, a surface treatment, or a fiber-opening treatment to obtain the surface-treated glass cloth of the present embodiment. The order of the deoiling treatment, surface treatment, or fiber-opening treatment is not particularly limited, but may be, for example, the order of fiber-opening treatment, deoiling treatment, and surface treatment.

[0054] Examples of the opening treatment include a treatment for widening the yarn width of the warp and weft yarns by applying a tension in the range of 30 to 200 N to the warp yarns of the glass cloth, such as opening by water jet pressure, opening by high-frequency vibration using a liquid as a medium, opening by pressure of a fluid having a surface pressure, or opening by pressure using a roll.

[0055] In the deoiling treatment, the glass cloth after the opening treatment is placed in a heating furnace at an atmospheric temperature in the range of 350 to 400°C for a time in the range of 32 to 75 hours, thereby thermally decomposing the sizing agent adhering to the glass cloth.

[0056] The surface treatment is carried out by first immersing the deoiled glass cloth in a silane coupling agent treatment solution containing a silane coupling agent at a concentration in the range of 0.3 to 4.0 mass %, squeezing out excess water, and then drying by heating at a temperature in the range of 80 to 180°C for a time in the range of 1 to 30 minutes to form a first surface treatment layer. １ The glass cloth on which the first surface treatment layer has been formed is immersed in a surface treatment resin composition treatment liquid containing, at a concentration in the range of 3 to 20 mass %, a surface treatment resin in which the integral value of the peak of a proton assigned to a benzene ring measured by H-NMR is in the range of 28 to 46% of the integral value of the peak of all protons, and after squeezing out excess water, the glass cloth is heated and dried at a temperature in the range of 80 to 180°C for a time in the range of 1 to 30 minutes to form a second surface treatment layer on the first surface treatment layer.

[0057] The silane coupling agent treatment liquid contains, for example, the silane coupling agent, an organic acid, and a surfactant.

[0058] Examples of the silane coupling agent that can be used include methacrylsilanes such as 3-methacryloxypropyltrimethoxysilane, and cationic silanes such as N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride and N-phenyl-3-aminopropyltrimethoxysilane hydrochloride.

[0059] Examples of the organic acid include acetic acid, formic acid, propionic acid, malonic acid, maleic acid, succinic acid, oxalic acid, malic acid, and citric acid, with acetic acid being preferred due to its ease of handling.

[0060] Examples of the surfactant include nonionic surfactants, cationic surfactants, anionic surfactants, and amphoteric surfactants. In this embodiment, the surfactants may be used alone or in combination of two or more.

[0061] Examples of nonionic surfactants include ethylene oxide propylene oxide alkyl ethers, polyoxyethylene alkyl ethers, polyoxyethylene-polyoxypropylene block copolymers, alkyl polyoxyethylene-polyoxypropylene block copolymer ethers, polyoxyethylene fatty acid esters, polyoxyethylene fatty acid monoesters, polyoxyethylene fatty acid diesters, polyoxyethylene sorbitan fatty acid esters, glycerol fatty acid ester ethylene oxide adducts, polyoxyethylene castor oil ethers, hydrogenated castor oil ethylene oxide adducts, alkylamine ethylene oxide adducts, fatty acid amide ethylene oxide adducts, glycerol fatty acid esters, polyglycerin fatty acid esters, pentaerythritol fatty acid esters, sorbitol fatty acid esters, sorbitan fatty acid esters, sucrose fatty acid esters, polyhydric alcohol alkyl ethers, fatty acid alkanolamides, acetylene glycol, acetylene alcohol, ethylene oxide adducts of acetylene glycol, and ethylene oxide adducts of acetylene alcohol.

[0062] Examples of cationic surfactants include alkyldimethylbenzylammonium chloride, alkyltrimethylammonium chloride, alkyldimethylethylammonium ethyl sulfate, higher alkylamine salts, ethylene oxide adducts of higher alkylamines, condensates of higher fatty acids and polyalkylenepolyamines, salts of esters of higher fatty acids and alkanolamines, salts of higher fatty acid amides, imidazoline-type cationic surfactants, and alkylpyridinium salts. Examples of higher alkylamine salts include acetates and hydrochlorides.

[0063] Examples of anionic surfactants include higher alcohol sulfates, higher alkyl ether sulfates, α-olefin sulfates, alkylbenzene sulfonates, α-olefin sulfonates, reaction products of fatty acid halides and N-methyltaurine, dialkyl sulfosuccinates, higher alcohol phosphates, and phosphate salts of higher alcohol ethylene oxide adducts.

[0064] Examples of amphoteric surfactants include amino acid-type amphoteric surfactants, betaine-type amphoteric surfactants, and imidazoline-type amphoteric surfactants. Examples of amino acid-type amphoteric surfactants include alkali metal salts of alkylaminopropionic acid. Examples of betaine-type amphoteric surfactants include alkyldimethylbetaine.

[0065] The surface treatment resin composition treatment liquid is a liquid obtained by diluting an emulsion resin containing a structural unit derived from the styrene-based monomer to a concentration of 3 to 20% by mass. Examples of the emulsion resin include a styrene-containing acrylic resin, a styrene-butadiene resin, and an acrylonitrile-butadiene-styrene copolymer resin (ABS resin).

[0066] As a result, it is possible to obtain a surface-treated glass cloth of this embodiment having a dielectric loss tangent in the range of 0.0001 to 0.0040 at a measurement frequency of 10 GHz.

[0067] The prepreg of this embodiment includes the surface-treated glass cloth of this embodiment and a matrix resin impregnated into the surface-treated glass cloth. The matrix resin may be any resin that is used as a matrix resin for prepregs, and is not particularly limited. However, the surface-treated glass cloth of this embodiment is particularly advantageous when the matrix resin is a resin with a low dielectric constant and a low dielectric loss tangent. Examples of the resin with a low dielectric constant and a low dielectric loss tangent include polyphenylene ether, LCP, cycloolefin polymer, divinylbenzene resin, and maleimide resin.

[0068] The prepreg of this embodiment can be produced by immersing the surface-treated glass cloth of this embodiment in a varnish containing the matrix resin and pre-drying it at a temperature in the range of 110 to 160°C for a time in the range of 5 to 20 minutes.

[0069] The printed wiring board of this embodiment can be obtained, for example, by curing the prepreg of this embodiment described above.

[0070] Next, examples of the present invention and comparative examples will be described.

[0071] [Example 1] In this example, first, a glass fiber having a low dielectric constant and a low dielectric loss tangent, with a filament diameter of 7 μm and a yarn weight of 20.8 g / 1000 m, was used to make a spunbond ... ２ The glass fiber had a dielectric constant of 4.7 and a dielectric loss tangent of 0.0025 at a measurement frequency of 10 GHz. The glass composition of the glass fiber was 54.5 mass % of SiO ２ and 19.4 mass% B ２ O ３ and 14.6% by mass of Al ２ O ３ 4.2% by weight of MgO, 4.1% by weight of CaO, and 1.9% by weight of TiO ２ and 0.1 mass% Fe ２ O ３ and a total of 0.2 mass% Li２ O, Na ２ O and K ２ O and 1.0 mass% F ２ In Tables 1 and 2, the glass composition is referred to as "low dielectric glass."

[0072] Next, the woven glass cloth was subjected to an opening treatment with a high-pressure water stream at a temperature of 40°C and a pressure of 2 MPa, and then heated at a temperature of 410°C for 36 hours to perform a deoiling treatment, thereby preparing a glass cloth to be surface-treated.

[0073] Next, the deoiled glass cloth was immersed in a silane coupling agent treatment liquid, excess water was squeezed out, and then the glass cloth was heated and dried at 110°C for 5 minutes to form a first surface treatment layer on the surface of the glass cloth. Next, the glass cloth with the first surface treatment layer formed thereon was immersed in a styrene-based emulsion resin treatment liquid, excess water was squeezed out, and then the glass cloth was heated and dried at 110°C for 5 minutes to form a second surface treatment layer, thereby obtaining a surface-treated glass cloth. The surface-treated glass cloth had a surface treatment layer consisting of a first surface treatment layer and a second surface treatment layer on the surface of the glass cloth, and the second surface treatment layer was formed on the first surface treatment layer.

[0074] The silane coupling agent treatment liquid used 3-methacryloxypropyltrimethoxysilane (manufactured by Toray Dow Corning Co., Ltd.) as the silane coupling agent, and was prepared by mixing the silane coupling agent with water to a composition of 1.0 mass % solids, 0.1 mass % acetic acid, and 0.05 mass % surfactant (polyoxyethylene alkyl ether), and stirring the mixture with a magnetic stirrer for 1 hour to prepare 2 liters of the liquid.

[0075] The styrene-based emulsion resin treatment liquid was prepared by diluting an emulsion obtained by polymerizing a styrene-based monomer (styrene) and (meth)acrylic acid ester-based monomers (2-ethylhexyl acrylate and methyl methacrylate) in a mass ratio of 75:25 with water to 10% by mass, to prepare 2 liters of the emulsion. The styrene-based emulsion resin was synthesized by known emulsion polymerization (see, for example, Japanese Patent No. 7217481, paragraph 0091 (Production Example 1)). However, the method is not limited thereto and may also be used for synthesis by known methods such as solution polymerization, bulk polymerization, and suspension polymerization. The ratio of 2-ethylhexyl acrylate to methyl methacrylate in the styrene-based emulsion resin was adjusted so as to obtain a predetermined Tg.

[0076] The styrene-based emulsion resin is a copolymer resin of a styrene-based monomer and a (meth)acrylic acid ester-based monomer, and the copolymer resin has a styrene content of 75% by mass and a glass transition temperature (Tg) of 35°C.

[0077] Next, the surface-treated glass cloth was cut into a size of 350 mm x 400 mm to obtain a surface-treated glass cloth piece, which was immersed in polyphenylene ether resin varnish and pre-dried at a temperature of 150°C for 10 minutes to obtain a prepreg.

[0078] The polyphenylene ether resin varnish contains 450 parts by mass of toluene (manufactured by Mitsubishi Gas Chemical Company, Inc., trade name: OPE-2St), 100 parts by mass of triallyl isocyanurate (manufactured by Evonik Japan Co., Ltd., trade name: TAICROS), 4 parts by mass of 1,3-di(t-butylperoxyisopropyl)benzene (manufactured by NOF Corporation, trade name: Perbutyl P), and 250 parts by mass of toluene (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.). The triallyl isocyanurate acts as a crosslinking agent.

[0079] Next, four sheets of the prepreg were laminated, and cellophane films were placed on top and bottom of them. Then, using a vacuum hot press (manufactured by Kitagawa Seiki Co., Ltd.), the temperature was 205°C and 18 kgf / cm ２ The laminate was heated and pressed at a pressure of 1000 kJ / cm2 for 1 hour in a vacuum to obtain a laminate having a thickness of about 0.3 mm as a simulated printed wiring board.

[0080] Next, the surface-treated glass cloth obtained in this example was measured for the amount of the surface treatment layer attached, the glass transition temperature (Tg) of the emulsion resin, １ The ratio of the integral value of the peak of the proton attributed to the benzene ring measured by H-NMR to the integral value of the peak of all protons ( １ The properties of the laminate obtained in this example, such as the ratio of the peak derived from the benzene ring in H-NMR measurement to the total integrated value, texture, and impregnation with the matrix resin, were measured or calculated by the following methods, and the processability was evaluated by the following methods. Furthermore, the whitening distance of the laminate obtained in this example was measured by the following method. The results are shown in Table 1.

[0081] In Table 1, 3-methacryloxypropyltrimethoxysilane is referred to as "methacrylic," and the type of emulsion resin containing a copolymer resin of a styrene-based monomer and a (meth)acrylic acid ester-based monomer is referred to as "styrene / acrylic."

[0082] [Method for measuring adhesion amount] According to JIS R 3420, first, the mass of the crucible is measured and designated as m0. Next, a surface-treated glass cloth test piece measuring 30 cm in the longitudinal direction and 20 cm in the width direction is placed in the crucible and heated in a dryer heated to 110°C for 60 minutes to dry the surface-treated glass cloth test piece. After drying, the crucible and the surface-treated glass cloth test piece are placed in a desiccator and cooled for 30 minutes. After cooling, the mass of the crucible and the surface-treated glass cloth test piece is measured and designated as m1. Next, the crucible and the surface-treated glass cloth test piece are placed in a muffle furnace heated to 625°C and incinerated for 30 minutes. After incineration, the crucible and the surface-treated glass cloth test piece are placed again in a desiccator and cooled for 90 minutes. After cooling, the mass of the crucible and the surface-treated glass cloth test piece is measured and designated as m2. Next, the adhesion amount is calculated using the following formula.

[0083] Adhesion amount (mass %)=(m1-m2) / (m1-m0)×100 [Method of calculating glass transition temperature (Tg)] The Tg of the copolymer resin is calculated as a theoretical value from the following FOX equation using the Tg of the homopolymer measured by DSC.

[0084] 1 / Tg=W １ / Tg１ +W ２ / Tg ２ +...+W ｎ / Tg ｎ In the above formula, Tg represents the glass transition temperature (unit: K) of a polymer (copolymer) of n types of monomer components (monomers 1 to n). １ , W ２ , ..., W ｎ represents the mass fraction of each monomer (1, 2, ..., n) relative to the total amount of n types of monomer components, and Tg １ , Tg ２ , ..., Tg ｎ represents the glass transition temperature (unit: K) of the homopolymer of each monomer (1, 2, ..., n). The following values ​​are used as the glass transition temperatures of the homopolymers of the monomers.

[0085] Styrene: 100°C, 2-ethylhexyl acrylate: -70°C, methyl methacrylate: 105°C [ １ Method for measuring the ratio of peaks derived from benzene rings to the total integrated value in H-NMR measurement: Surface-treated glass cloth cut to a size of 10 cm x 10 cm is immersed in 30 mL of toluene (special grade reagent, manufactured by Junsei Chemical Co., Ltd.) for 5 minutes and washed. The washing liquid is evaporated to completely volatilize the toluene. The remaining components are dissolved in chloroform-D1 (Sigma-Aldrich; 0.03 vol.% TMS, deuteration degree min. 99.8% for NMR spectroscopy (stabilized with silver)) containing tetramethylsilane (TMS) as an internal standard. １ Measurements were performed using a H-NMR (nuclear magnetic resonance analyzer manufactured by Oxford Instruments (trade name: Pulsar HFC, 60 MHz)). At least 20 integrations were performed, and the TMS peak was set at 0.0 ppm. The integral values ​​of the peaks present in the range of 6.3 to 7.2 ppm were calculated based on the TMS peak (peak at 0.0 ppm) and the small amount of chloroform (CHCH) contained in chloroform-D1. ３The value obtained by dividing the integral of all peaks excluding the peak of protons at 73.3 ppm (peak at about 73.3 ppm) by the integral of all peaks and multiplying the result by 100 is the ratio of the peak of protons attributable to the benzene ring to the integral of all proton peaks.

[0086] [Method for measuring texture] A surface-treated glass cloth is cut into a size of 3 cm wide and 17 cm long to prepare a test piece. Next, the test piece is fixed at a portion 3 cm inside from the edge of a flat stand of 5.5 cm x 3.5 cm horizontal to the ground at a height of 25 cm, and the remaining portion of 14 cm is hung outside the stand, and the height to which the surface-treated glass cloth hangs down vertically is measured. The larger the value, the softer the texture, and the smaller the value, the harder the texture.

[0087] [Method for measuring impregnation] A surface-treated glass cloth was cut out at three points: a point 200 mm inward from one end of the surface-treated glass cloth in the width direction, a point 200 mm inward from the other end, and a point at the center of the surface-treated glass cloth in the width direction, to obtain a 60 mm x 40 mm test piece for evaluating impregnation. The test piece for evaluating impregnation was immersed in benzyl alcohol, and the time from immediately after immersion until the benzyl alcohol completely permeated the glass cloth piece for evaluating impregnation was measured in the warp direction. Five glass cloth pieces for evaluating impregnation were used for each measurement point, and the average value was calculated for each measurement point.

[0088] [Method for Measuring Whitening Distance] The laminate was cut into a size of 7 cm x 4 cm using an NC router, and 2 cm slits were made in each of the warp and weft directions to prepare test specimens. A 1 mol / L aqueous solution of NaOH (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was placed in a beaker and heated to 60°C. The test specimen was immersed in the NaOH aqueous solution for 30 hours, and the whitening distance due to peeling at the resin-glass interface in the warp and weft directions was measured at 24 points in each direction using a digital microscope (manufactured by Keyence Corporation) at 100x magnification. The average value was calculated and used as the whitening distance. The whitening distance due to peeling correlates with the insulation reliability of the printed wiring board; the shorter the whitening distance, the higher the insulation reliability.

[0089] The values ​​obtained by dividing the measured values ​​of Examples 1 to 5 and Comparative Examples 1 to 7 by the measured value of Reference Example 1 described later, and the values ​​obtained by dividing the measured value of Example 6 by the measured value of Reference Example 2 described later, were used as indices relative to the Reference Examples. The indices relative to the Reference Examples indicate an improvement index of the whitening distance from the Reference Examples.

[0090] [Method for evaluating processability] In the production line from the heat drying step after the formation of the second surface treatment layer on the surface-treated glass cloth to the winding up of the surface-treated glass cloth, the case where no wrinkles are generated is evaluated as "Good", the case where wrinkles are generated but do not leave marks is evaluated as "Good", and the case where wrinkles that leave marks are generated is evaluated as "Poor".

[0091] [Reference Example 1] In this reference example, a surface-treated glass cloth and a laminate were obtained in exactly the same manner as in Example 1, except that the surface treatment of the glass cloth did not involve immersing the glass cloth in an emulsion resin treatment liquid.

[0092] Next, the surface-treated glass cloth obtained in this Reference Example was subjected to the same procedures as in Example 1 to measure the adhesion amount of the surface-treated layer, １ The ratio of the integral value of the peak of the protons attributable to the benzene ring measured by H-NMR to the integral value of the peak of all protons, the texture, and the impregnation of the matrix resin were measured or calculated to evaluate the processability. Furthermore, the whitening distance of the laminate obtained in this Reference Example was measured in exactly the same manner as in Example 1. The results are shown in Table 1.

[0093] In this example, a surface-treated glass cloth and a laminate were obtained in exactly the same manner as in Example 1, except that a styrene-butadiene copolymer styrene emulsion resin (manufactured by ENEOS Corporation, product name: SBL 0597C) was used as the styrene emulsion resin. Since the styrene emulsion resin used in this example was a commercially available product, the styrene content in the copolymer resin was unknown.

[0094] Next, the surface-treated glass cloth obtained in this example was subjected to the same procedure as in Example 1 to measure the adhesion amount of the surface-treated layer, １The ratio of the integral value of the peak of the protons attributable to the benzene ring to the integral value of the peak of all protons measured by H-NMR, the texture, and the impregnation property of the matrix resin were measured to evaluate the processability. The glass transition temperature (Tg) of the emulsion resin was recorded as a catalog value. In addition, the whitening distance of the laminate obtained in this example was measured exactly as in Example 1. The results are shown in Table 1.

[0095] In Table 1, the type of emulsion resin containing a copolymer resin of styrene and butadiene is referred to as "styrene / butadiene."

[0096] [Example 3] In this example, a surface-treated glass cloth and a laminate were obtained in exactly the same manner as in Example 1, except that a styrene-based emulsion resin treatment liquid prepared by polymerizing a styrene-based monomer (styrene) and (meth)acrylic acid ester-based monomers (2-ethylhexyl acrylate and methyl methacrylate) in a mass ratio of 70:30 was used.

[0097] Next, the surface-treated glass cloth obtained in this example was subjected to the same procedures as in Example 1 to measure the amount of the surface-treated layer attached, the glass transition temperature (Tg) of the emulsion resin, １ The ratio of the integral value of the peak of the protons attributable to the benzene ring measured by H-NMR to the integral value of the peak of all protons, the texture, and the impregnation of the matrix resin were measured or calculated to evaluate the processability. Furthermore, the whitening distance of the laminate obtained in this example was measured in exactly the same manner as in Example 1. The results are shown in Table 1.

[0098] Example 4 In this example, a surface-treated glass cloth and a laminate were obtained in exactly the same manner as in Example 1, except that a styrene-based emulsion resin treatment liquid prepared by polymerizing a styrene-based monomer (styrene) and (meth)acrylic acid ester-based monomers (2-ethylhexyl acrylate and methyl methacrylate) in a mass ratio of 74:26 was used.

[0099] Next, the surface-treated glass cloth obtained in this example was subjected to the same procedures as in Example 1 to measure the amount of the surface-treated layer attached, the glass transition temperature (Tg) of the emulsion resin, １The ratio of the integral value of the peak of the protons attributable to the benzene ring measured by H-NMR to the integral value of the peak of all protons, the texture, and the impregnation of the matrix resin were measured or calculated to evaluate the processability. Furthermore, the whitening distance of the laminate obtained in this example was measured in exactly the same manner as in Example 1. The results are shown in Table 1.

[0100] Example 5 In this example, a surface-treated glass cloth and a laminate were obtained in exactly the same manner as in Example 1, except that a styrene-based emulsion resin treatment liquid prepared by polymerizing a styrene-based monomer (styrene) and (meth)acrylic acid ester-based monomers (2-ethylhexyl acrylate and methyl methacrylate) in a mass ratio of 81:19 was used.

[0101] Next, the surface-treated glass cloth obtained in this example was subjected to the same procedures as in Example 1 to measure the amount of the surface-treated layer attached, the glass transition temperature (Tg) of the emulsion resin, １ The ratio of the integral value of the peak of the protons attributable to the benzene ring measured by H-NMR to the integral value of the peak of all protons, the texture, and the impregnation of the matrix resin were measured or calculated to evaluate the processability. Furthermore, the whitening distance of the laminate obtained in this example was measured in exactly the same manner as in Example 1. The results are shown in Table 1.

[0102] Example 6 In this example, a surface-treated glass cloth and a laminate were obtained in exactly the same manner as in Example 1, except that N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride was used as the silane coupling agent.

[0103] Next, the surface-treated glass cloth obtained in this example was subjected to the same procedures as in Example 1 to measure the amount of the surface-treated layer attached, the glass transition temperature (Tg) of the emulsion resin, １The ratio of the integral value of the peak of the protons assigned to the benzene ring measured by H-NMR to the integral value of the peak of all protons, the texture, and the impregnation of the matrix resin were measured or calculated to evaluate the processability. Furthermore, the whitening distance of the laminate obtained in this example was measured in exactly the same manner as in Example 1. Regarding the whitening distance, in this example, the measured value in this example was divided by the measured value in Reference Example 2 described below, and the resulting value was used as an index relative to the Reference Example. The results are shown in Table 1.

[0104] In Table 1, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride is referred to as "cationic."

[0105] [Reference Example 2] In this reference example, a surface-treated glass cloth and a laminate were obtained in exactly the same manner as in Example 6, except that the surface treatment of the glass cloth did not involve immersing the glass cloth in an emulsion resin treatment liquid.

[0106] Next, the surface-treated glass cloth obtained in this Reference Example was subjected to the same procedures as in Example 1 to measure the adhesion amount of the surface-treated layer, １ The ratio of the integral value of the peak of the protons attributable to the benzene ring measured by H-NMR to the integral value of the peak of all protons, the texture, and the impregnation of the matrix resin were measured or calculated to evaluate the processability. Furthermore, the whitening distance of the laminate obtained in this Reference Example was measured in exactly the same manner as in Example 1. The results are shown in Table 1.

[0107] In this comparative example, a surface-treated glass cloth and a laminate were obtained in exactly the same manner as in Example 1, except that an emulsion resin treatment liquid containing a copolymer resin of acrylic resin (2-ethylhexyl acrylate and methyl methacrylate) was used. The emulsion resin did not contain any structural units derived from styrene-based monomers.

[0108] Next, the surface-treated glass cloth obtained in this comparative example was subjected to the same procedures as in Example 1 to measure the adhesion amount of the surface treatment layer, the glass transition temperature (Tg) of the emulsion resin, １The ratio of the integral value of the peak of the protons attributable to the benzene ring measured by H-NMR to the integral value of the peak of all protons, the texture, and the impregnation of the matrix resin were measured or calculated to evaluate the processability. Furthermore, the whitening distance of the laminate obtained in this comparative example was measured in exactly the same manner as in Example 1. The results are shown in Table 2.

[0109] In Table 2, 3-methacryloxypropyltrimethoxysilane is referred to as "methacrylic," and the type of emulsion resin containing the polymer resin of the (meth)acrylic acid ester monomer is referred to as "acrylic."

[0110] [Comparative Example 2] In this comparative example, a surface-treated glass cloth and a laminate were obtained in exactly the same manner as in Example 1, except that a styrene-based emulsion resin treatment liquid prepared by polymerizing a styrene-based monomer (styrene) and (meth)acrylic acid ester-based monomers (2-ethylhexyl acrylate and methyl methacrylate) in a mass ratio of 40:60 was used.

[0111] Next, the surface-treated glass cloth obtained in this comparative example was subjected to the same procedures as in Example 1 to measure the adhesion amount of the surface treatment layer, the glass transition temperature (Tg) of the emulsion resin, １ The ratio of the integral value of the peak of the protons attributable to the benzene ring measured by H-NMR to the integral value of the peak of all protons, the texture, and the impregnation of the matrix resin were measured or calculated to evaluate the processability. Furthermore, the whitening distance of the laminate obtained in this comparative example was measured in exactly the same manner as in Example 1. The results are shown in Table 2.

[0112] In Table 2, the type of emulsion resin containing a copolymer resin of a styrene-based monomer and a (meth)acrylic acid ester-based monomer is referred to as "styrene / acrylic."

[0113] [Comparative Example 3] In this comparative example, a surface-treated glass cloth and a laminate were obtained in exactly the same manner as in Example 1, except that a styrene-based emulsion resin treatment liquid prepared by polymerizing a styrene-based monomer (styrene) and (meth)acrylic acid ester-based monomers (2-ethylhexyl acrylate and methyl methacrylate) in a mass ratio of 54:46 was used.

[0114] Next, the surface-treated glass cloth obtained in this comparative example was subjected to the same procedures as in Example 1 to measure the adhesion amount of the surface treatment layer, the glass transition temperature (Tg) of the styrene-based emulsion resin, １ The ratio of the integral value of the peak of the protons attributable to the benzene ring measured by H-NMR to the integral value of the peak of all protons, the texture, and the impregnation of the matrix resin were measured or calculated to evaluate the processability. Furthermore, the whitening distance of the laminate obtained in this comparative example was measured in exactly the same manner as in Example 1. The results are shown in Table 2.

[0115] [Comparative Example 4] In this comparative example, a surface-treated glass cloth and a laminate were obtained in exactly the same manner as in Example 1, except that a styrene-based emulsion resin treatment liquid prepared by polymerizing a styrene-based monomer (styrene) and (meth)acrylic acid ester-based monomers (2-ethylhexyl acrylate and methyl methacrylate) in a mass ratio of 93:7 was used.

[0116] Next, the surface-treated glass cloth obtained in this comparative example was subjected to the same procedures as in Example 1 to measure the adhesion amount of the surface treatment layer, the glass transition temperature (Tg) of the styrene-based emulsion resin, １ The ratio of the integral value of the peak of the protons attributable to the benzene ring measured by H-NMR to the integral value of the peak of all protons, the texture, and the impregnation of the matrix resin were measured or calculated to evaluate the processability. Furthermore, the whitening distance of the laminate obtained in this comparative example was measured in exactly the same manner as in Example 1. The results are shown in Table 2.

[0117] Comparative Example 5 In this comparative example, a surface-treated glass cloth and a laminate were obtained in exactly the same manner as in Example 1, except that a styrene-based emulsion resin treatment liquid prepared by polymerizing a styrene-based monomer (styrene) and (meth)acrylic acid ester-based monomers (2-ethylhexyl acrylate and methyl methacrylate) in a mass ratio of 88:12 was used.

[0118] Next, the surface-treated glass cloth obtained in this comparative example was subjected to the same procedures as in Example 1 to measure the adhesion amount of the surface treatment layer, the glass transition temperature (Tg) of the styrene-based emulsion resin, １The ratio of the integral value of the peak of the protons attributable to the benzene ring measured by H-NMR to the integral value of the peak of all protons, the texture, and the impregnation of the matrix resin were measured or calculated to evaluate the processability. Furthermore, the whitening distance of the laminate obtained in this comparative example was measured in exactly the same manner as in Example 1. The results are shown in Table 2.

[0119] In this comparative example, the solid content of the silane coupling agent in the silane coupling agent treatment solution was 10.0 mass %, and the glass cloth was not immersed in an emulsion resin treatment solution at all in the surface treatment of the glass cloth. In this comparative example, the solid content of the silane coupling agent in the silane coupling agent treatment solution was 10.0 mass %, and as a result, the adhesion amount of the surface treatment layer was increased compared to Example 1.

[0120] Next, the surface-treated glass cloth obtained in this comparative example was subjected to the same procedures as in Example 1 to measure the adhesion amount of the surface-treated layer, １ The ratio of the integral value of the peak of the protons attributable to the benzene ring measured by H-NMR to the integral value of the peak of all protons, the texture, and the impregnation of the matrix resin were measured or calculated to evaluate the processability. Furthermore, the whitening distance of the laminate obtained in this comparative example was measured in exactly the same manner as in Example 1. The results are shown in Table 2.

[0121] In this comparative example, the solid content of the silane coupling agent in the silane coupling agent treatment solution was set to 20.0 mass %, and the glass cloth was not immersed in an emulsion resin treatment solution at all in the surface treatment of the glass cloth. In this comparative example, the solid content of the silane coupling agent in the silane coupling agent treatment solution was set to 20.0 mass %, and as a result, the adhesion amount of the surface treatment layer was increased compared to Example 1.

[0122] Next, the surface-treated glass cloth obtained in this comparative example was subjected to the same procedures as in Example 1 to measure the adhesion amount of the surface-treated layer, １The ratio of the integral value of the peak of the protons attributable to the benzene ring measured by H-NMR to the integral value of the peak of all protons, the texture, and the impregnation of the matrix resin were measured or calculated to evaluate the processability. Furthermore, the whitening distance of the laminate obtained in this comparative example was measured in exactly the same manner as in Example 1. The results are shown in Table 2.

[0123]

[0124] From Table 1, it can be seen that the surface treatment layer contains a silane coupling agent and a structural unit derived from a styrene-based monomer, １ The surface-treated glass cloths of Examples 1 to 6, which contain a surface treatment resin in which the integral value of the peak of protons assigned to a benzene ring as measured by H-NMR is in the range of 28 to 46% of the integral value of the peaks of all protons, can obtain excellent adhesion to the matrix resin, and it is clear that even if the adhesion amount of the surface treatment layer is increased to 0.8 mass % or more, the impregnation of the matrix resin into the glass fiber is not impaired, the texture does not become excessively hard, and excellent processability can be obtained when producing a prepreg.

[0125] On the other hand, from Table 2, it can be seen that the surface treatment layer does not contain any structural units derived from styrene-based monomers, １ A surface-treated glass cloth of Comparative Example 1 containing a surface-treatment resin in which the integral value of the peak of protons assigned to a benzene ring measured by H-NMR is 0, and １ The surface-treated glass cloths of Comparative Examples 2 and 3, in which the integral value of the peak of protons assigned to the benzene ring measured by H-NMR does not reach 28% of the integral value of the peak of all protons, have a hard texture and are unable to obtain excellent processability. It is clear that not only is the impregnation of the glass fibers of the surface-treated glass cloth with the matrix resin reduced, but also the adhesion of the matrix resin to the surface-treated glass cloth is inferior to that of the surface-treated glass cloths of Examples 1 to 6.

[0126] Also, from Table 2, １The surface-treated glass cloths of Comparative Examples 4 and 5, in which the integral value of the peak of protons assigned to the benzene ring measured by H-NMR exceeds 46% of the integral value of the peak of all protons, clearly show a decrease in the impregnation of the glass fibers of the surface-treated glass cloth with the matrix resin, and also show a decrease in the adhesiveness of the matrix resin to the surface-treated glass cloth compared to the surface-treated glass cloths of Examples 1 to 6.

[0127] Furthermore, it is clear from Table 2 that the surface-treated glass cloths of Comparative Examples 6 and 7, in which the solid content of the silane coupling agent in the silane coupling agent treatment liquid was increased while the glass cloth was not subjected to any treatment of immersing in an emulsion resin treatment liquid, had a reduced ability to impregnate the glass fibers of the surface-treated glass cloth with the matrix resin, and the adhesiveness of the matrix resin to the surface-treated glass cloth was also significantly inferior to that of the surface-treated glass cloths of Examples 1 to 6.

Claims

1. A surface-treated glass cloth having a surface-treatment layer on a surface thereof, the surface-treatment layer containing a silane coupling agent and a surface-treatment resin, the surface-treatment resin containing a structural unit derived from a styrene-based monomer, １ 1. A surface-treated glass cloth, characterized in that an integral value of a proton peak assigned to a benzene ring, as measured by H-NMR, is in the range of 28 to 46% of an integral value of all proton peaks.

2. The surface-treated glass cloth according to claim 1, wherein the silane coupling agent is methacrylsilane.

3. A surface-treated glass cloth according to claim 1, characterized in that the styrene-based monomer is one or more monomers selected from styrene-based monomers represented by the following general formula (1): [In the formula, R １ is hydrogen or an alkyl group having 1 to 2 carbon atoms; R ２ ~R ６ each independently represents a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an alkynyl group, or an aryl group, and may contain a heteroatom.

4. The surface-treated glass cloth according to claim 1, characterized in that the surface treatment layer comprises a first surface treatment layer containing a silane coupling agent and a second surface treatment layer containing the surface treatment resin.

5. The surface-treated glass cloth according to claim 1, wherein the amount of the surface treatment layer adhered thereto is in the range of 0.8 to 5.0 mass % based on the total amount of the surface-treated glass cloth.

6. The surface-treated glass cloth according to claim 1, characterized in that the dielectric tangent at a measurement frequency of 10 GHz is in the range of 0.0001 to 0.0040.

7. A prepreg comprising the surface-treated glass cloth according to any one of claims 1 to 6.

8. A printed wiring board comprising the surface-treated glass cloth according to any one of claims 1 to 6.

Images