Silane-treated glass cloth

Abstract

To provide a glass cloth which does not degrade a dielectric characteristic even under a high temperature and a high humidity, and has a low transmission loss.SOLUTION: A silane-treated glass cloth having an ignition loss of 0.08 mass% or lower is obtained by surface-treatment with an organooxysilane aqueous solution containing respective predetermined amounts of (i) an organooxysilane represented by formula (1), and containing a functional group such as an epoxy group, and (ii) a partial hydrolysate of the constituent (i), or an organooxysilane aqueous solution containing respective predetermined amounts of the constituent (i) an organooxysilane represented by formula (1), and containing a functional group such as an epoxy group, (iii) an organooxysilane represented by formula (2), and containing an univalent hydrocarbon group such as an alkyl group, and (iv) a partial (co-)hydrolysate of a predetermined amount of the constituent (i) and a predetermined amount of the constituent (iii).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to silane-treated glass cloth, and more specifically, to silane-treated glass cloth that maintains a low dielectric loss tangent, a prepreg containing this silane-treated glass cloth, and a printed circuit board. [Background technology]

[0002] Currently, with the increasing performance and high-speed communication capabilities of information terminals such as smartphones, the printed circuit boards used are undergoing significant advancements in density, thinning, dielectric strength, and dielectric loss tangent. As insulating materials for these printed circuit boards, laminates are widely used, which are obtained by impregnating glass cloth with a thermosetting resin such as epoxy resin (hereinafter referred to as "matrix resin"), laminating these prepregs, and then curing them under heat and pressure.

[0003] It is known that signal transmission loss in a substrate improves with materials that have smaller dielectric constants (ε) and dielectric loss tangents (tanδ), as shown by Edward A. Wolff's equation: transmission loss ∝√ε × tanδ. In particular, from the above equation, it is known that the dielectric loss tangent contributes significantly to transmission loss. Therefore, a low dielectric loss tangent is required for glass cloth, and Patent Documents 1 to 3 propose glass cloth with improved dielectric properties.

[0004] Furthermore, since the cause of the increased dielectric loss tangent of glass cloth is organic matter remaining physically attached to the glass yarn surface, Patent Document 4 proposes a method of cleaning and removing with an organic solvent trace amount of thermally oxidized sizing agent degradation products that could not be reduced by heat cleaning, as well as residues and modified substances of surface treatment agents, such as silane coupling agents, that are physically attached to the glass surface without forming chemical bonds and cannot be reduced or removed by water washing. However, this method involves additional processing steps, such as cleaning and drying with a solvent after surface treatment, and also includes solvent treatment, resulting in increased costs.

[0005] In Patent Document 5, instead of surface treatment with a silane coupling agent, a glass cloth for a low dielectric material suitably used for a printed wiring board has been proposed by surface treatment with an alkoxy group-containing organopolysiloxane composition. However, there is a demand for a highly reliable printed wiring board that is more excellent in reactivity with glass cloth and has less deterioration of dielectric characteristics even under high temperature and high humidity. In particular, from the viewpoint of achieving sufficient transmission speed performance in future applications such as 5G communication, there is still a need for improvement even in glass cloths having excellent low dielectric constant and low dielectric tangent low dielectric characteristics.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0007] As described above, an organic substrate obtained by impregnating a glass cloth with a resin and curing it under pressure is widely used as a mounting substrate for semiconductors. On the other hand, high-speed communication using millimeter waves such as 5G is being put into practical use. Against this background, in order to reduce transmission loss of the mounting substrate, an organic resin and a glass cloth having low dielectric characteristics are desired. The present invention has been made in view of the above circumstances, and an object thereof is to provide a glass cloth that does not deteriorate in dielectric characteristics even under high temperature and high humidity and has little transmission loss even at high frequencies.

Means for Solving the Problems

[0008] As a result of intensive studies to solve the above problems, the inventors of the present invention found that by previously reacting the organoxy group of organoxysilane with water to convert some of the organoxy groups into hydroxyl groups, or by condensing these to form oligomers and treating a glass cloth therewith, the reaction on the surface of the glass cloth proceeds rapidly, the unreacted organoxysilane and by-products are extremely reduced, and a silane-treated glass cloth with extremely low transmission loss can be obtained. Further, by using in combination an organoxysilane having a predetermined functional group and an organoxysilane containing a hydrocarbon group such as an alkyl group, the surface of the glass cloth can be hydrophobized while improving the reactivity, so that deterioration of dielectric properties can be prevented even under high humidity, the transmission loss of the glass cloth can be reduced, and it was found that an organic substrate with extremely low transmission loss can be obtained by using the obtained silane-treated glass cloth, leading to the completion of the present invention.

[0009] That is, the present invention relates to 1. (i) One or more organoxysilanes represented by the following general formula (1), (ii) A partial hydrolyzate of the component (i) and containing a silane-treated glass cloth having a loss on ignition of 0.08% by mass or less, which is surface-treated with an organoxysilane aqueous solution in which the content of the component (i) is 30 to 95% by mass and the content of the component (ii) is 5 to 70% by mass in the total of the components (i) and (ii), R 1 X R 2 Y Si(OR 3 ) 4-X-Y (1) (In the formula, R 1 is a monovalent organic group having 1 to 20 carbon atoms containing an epoxy group, an amino group, an unsaturated group, a mercapto group, an isocyanate group, an acid anhydride group or a hydroxyl group, R 2 is an alkyl group or an aryl group having 1 to 10 carbon atoms, R 3(where X is a monovalent hydrocarbon group with 1 to 10 carbon atoms, X is 1 or 2, Y is 0 or 1, and X+Y is 1 or 2.) 2. (i) One or more organoxysilanes represented by the following general formula (1), (iii) One or more organoxysilanes represented by the following general formula (2), (iv) Partial (co) hydrolysates of component (i) 50-95% by mass and component (iii) 5-50% by mass It contains, Silane-treated glass cloth having a loss on ignition of 0.08% by mass or less, surface-treated with an aqueous organooxysilane solution in which the total content of components (i) and (iii) is 30 to 95% by mass and the content of component (iv) is 5 to 70% by mass, R 1 X R 2 Y Si(OR 3 ) 4-X-Y (1) (In the formula, R 1 R is a monovalent organic group having 1 to 20 carbon atoms, including epoxy groups, amino groups, unsaturated groups, mercapto groups, isocyanate groups, acid anhydride groups, or hydroxyl groups. 2 R is an alkyl or aryl group having 1 to 10 carbon atoms. 3 (where X is a monovalent hydrocarbon group with 1 to 10 carbon atoms, X is 1 or 2, Y is 0 or 1, and X+Y is 1 or 2.) R 4 Z Si(OR 5 ) 4-Z (2) (In the formula, R 4 R is a monovalent hydrocarbon group having 1 to 20 carbon atoms. 5 (This refers to a monovalent hydrocarbon group with 1 to 10 carbon atoms. Z is an integer between 1 and 3.) 3. A silane-treated glass cloth according to 1 or 2, wherein the organoxysilane aqueous solution contains a hydrolysis / condensation catalyst with a boiling point of 120°C or lower. 4. The silane-treated glass cloth according to 3, wherein the hydrolysis / condensation catalyst is ammonia or acetic acid. 5. The silane-treated glass cloth according to claim 1 or 2, wherein the glass cloth is woven from a glass yarn made by bundling 30 to 250 glass filaments, each having an SiO2 composition of 45 to 100% by mass and a filament diameter of 3 to 20 μm. 6. The silane-treated glass cloth according to 5, wherein the SiO2 composition of the glass filament is 99-100% by mass. 7. A prepreg comprising a silane-treated glass cloth as described in 1 or 2 and a matrix resin impregnated in the silane-treated glass cloth. 8. The prepreg according to 7, wherein the matrix resin is one or more resins selected from epoxy resin, silicone resin, polyimide resin, bismaleimide resin, polyphenylene ether resin, and polytetrafluoroethylene resin. 9. Printed circuit board with prepreg as described in 7. To provide. [Effects of the Invention]

[0010] According to the present invention, by treating glass cloth with organoxysilane or its partial (co)hydrolyzed product, which has high reactivity and can impart low hygroscopicity, it is possible to provide silane-treated glass cloth that is highly reliable and exhibits little deterioration of dielectric properties even under high humidity. [Modes for carrying out the invention]

[0011] The present invention will be described in further detail below. [1] Silane-treated glass cloth The silane-treated glass cloth of the present invention is (i) One or more organoxysilanes represented by the following general formula (1), (ii) Partial hydrolysate of component (i) An aqueous solution of organoxysilane containing, or (i) One or more organoxysilanes represented by the following general formula (1), (iii) One or more organoxysilanes represented by the following general formula (2), (iv) Partial (co)hydrolyzed products of components (i) and (iii) Aqueous solution of organooxysilane containing It has been surface-treated. In the present invention, (ii) "partial hydrolysate of component (i)" means a partial hydrolysate and partial hydrolysate condensate of component (i), or a partial co-hydrolysate, partial hydrolysate condensate and partial co-hydrolysate condensate of component (i). Furthermore, (iv) "partial (co)hydrolyzed products of components (i) and (iii)" means including the partial cohydrolyzed product of component (i), the partial cohydrolyzed product of component (iii), the partial hydrolyzed condensate of component (i), the partial hydrolyzed condensate of component (iii), and the partial cohydrolyzed condensate of components (i) and (iii).

[0012] [Glass cloth] The glass cloth used in this invention is preferably a glass cloth composed of glass yarn made up of multiple glass filaments. The silicon (Si) content in the glass filament is not particularly limited, but the SiO2 (silicon dioxide) composition is preferably 45 to 100% by mass. The glass filament may have other compositions besides SiO2. Other compositions are not particularly limited, but examples include Al2O3, CaO, MgO, B2O3, TiO2, Na2O, K2O, Sr2O3, Fe2O3, etc.

[0013] The glass cloth used in laminates is typically made of a type of glass called E-glass (alkali-free glass). In the glass cloth used in this invention, in addition to E-glass, other types of glass such as L-glass, NE-glass, D-glass, L2-glass, T-glass, silica glass, and quartz glass may also be used. From the viewpoint of dielectric properties, the silicon (Si) content of the glass filaments contained in the glass yarn constituting the glass cloth is more preferably 95 to 100% by mass, even more preferably 99 to 100% by mass, even more preferably 99.5 to 100% by mass, and particularly preferably 99.9 to 100% by mass, in terms of SiO2 (silicon dioxide).

[0014] The average filament diameter of the glass filament is preferably 3 to 20 μm, and the number of filaments in the glass yarn is preferably 30 to 250.

[0015] The density of the warp and weft threads constituting the glass cloth is preferably 10 to 140 threads / inch, independently of each other, and the thickness of the glass cloth is preferably 8 to 100 μm. Furthermore, the weight (basis weight) of the glass cloth is preferably 8 to 250 g / m². 2 More preferably 8-100 g / m² 2 And more preferably 8-80 g / m 2 The g / m² is particularly preferably 8-50 g / m². 2 That is the case. The weaving structure of the glass cloth is not particularly limited, but examples include plain weave, twill weave, satin weave, and twill weave. Among these, the plain weave structure is more preferred.

[0016] [Organoxysilane aqueous solution] The organoxysilanes used in the present invention are broadly classified into two types: those represented by the following general formula (1) and referred to as silane coupling agents containing a predetermined functional group (hereinafter also referred to as "silane coupling agents"), and those represented by the following general formula (2) and having alkyl groups or aryl groups, but not containing the above predetermined functional group (hereinafter also referred to as "unfunctional organoxysilanes").

[0017] In the present invention, either (1) an aqueous solution of organoxysilane containing (i) a silane coupling agent and (ii) a partial hydrolysate of component (i) (hereinafter also referred to as the "first aqueous solution"), or (2) an aqueous solution of organoxysilane containing (i) a silane coupling agent, (iii) an unfunctionalized organoxysilane, and (iv) a partial (co) hydrolysate of components (i) and (iii) (hereinafter also referred to as the "second aqueous solution").

[0018] The above-mentioned silane coupling agent and unfunctionalized organoxysilane are susceptible to hydrolysis, and the partially hydrolyzed and condensed silane derivatives are highly reactive, readily reacting with glass on the glass cloth surface and forming a uniform coating film on the glass cloth surface. Furthermore, by using a silane coupling agent having a reactive functional group in combination with an unfunctionalized organoxysilane having an alkyl group with a predetermined number of carbon atoms, the glass cloth surface becomes hydrophobic, and the amount of moisture absorbed can be reduced. In particular, silane coupling agents having long-chain spacers possess adhesive and hydrophobic properties, exhibiting excellent properties in line with the objectives of the present invention even without the use of unfunctionalized organoxysilane, and are therefore preferred silane coupling agents.

[0019] (1) First aqueous solution The first aqueous solution used in the present invention comprises (i) a silane coupling agent represented by the following general formula (1) and (ii) a partial hydrolysate of component (i) (hereinafter, components (i) and (ii) together are also referred to as "components of the first aqueous solution"). R 1 X R 2 Y Si(OR 3 ) 4-X-Y (1)

[0020] In the formula, R 1 R is a monovalent organic group having 1 to 20 carbon atoms, including epoxy groups, amino groups, unsaturated groups, mercapto groups, isocyanate groups, acid anhydride groups, or hydroxyl groups. 2 R is an alkyl or aryl group having 1 to 10 carbon atoms. 3X is a monovalent hydrocarbon group having 1 to 10 carbon atoms, X is 1 or 2, Y is 0 or 1, and X+Y is 1 or 2.

[0021] R 1 Specific examples of monovalent organic groups include epoxy ring-containing organic groups such as 2-glycidoxyethyl, 3-glycidoxypropyl, 4-glycidoxybutyl, 8-glycidoxyoctyl, and 2-(3,4-epoxycyclohexyl)ethyl groups; amino group-containing organic groups such as 3-aminopropyl, N-2-(aminoethyl)-3-aminopropyl, and N-2(aminoethyl)-8-aminooctyltrimethoxysilane; unsaturated group-containing organic groups such as vinyl, 5-hexenyltrimethoxysilane, 7-octenylmethoxysilane, 3-acryloxypropyl, 3-methacryloxypropyl, styryl, and methacrylamide groups; mercapto group-containing organic groups such as 2-mercaptoethyl, 3-mercaptopropyl, and 4-mercaptobutyl groups; isocyanate group-containing organic groups such as 2-isocyanateethyl, 3-isocyanatepropyl, and 4-isocyanatebutyl groups; and acid anhydride groups such as succinic anhydride groups. Among these, R 1 Preferably, the organic group contains an epoxy ring, an amino group, or an unsaturated group.

[0022] R 2 The alkyl group may be linear, branched, or cyclic. Specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, and cyclohexyl groups. R 2 Specific examples of aryl groups include phenyl and tolyl groups.

[0023] R 3 The monovalent hydrocarbon group may be linear, branched, or cyclic, and examples include alkyl groups having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms. Specific examples of alkyl groups include R 2 Examples similar to the base exemplified above can be given. Among these, R 3 The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group.

[0024] X is either 1 or 2, but 1 is preferred. Y is either 0 or 1, but 0 is preferred. X+Y is either 1 or 2, but 1 is preferred.

[0025] Specific examples of the silane coupling agent of component (i) used in the present invention include epoxy-based silane coupling agents such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 8-glycidoxyoctyltrimethoxysilane; amino-based silane coupling agents such as 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, and N-2(aminoethyl)-8-aminooctyltrimethoxysilane; vinyltrimethoxysilane, vinyltriethoxysilane, and 5-hex Examples include unsaturated group-containing silane coupling agents such as senyltrimethoxysilane, 7-octenylmethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 8-methacryloxyoctyltrimethoxysilane, p-styryltrimethoxysilane, and methacrylamide group-containing silane compounds; mercapto-type silane coupling agents such as 3-mercaptopropyltrimethoxysilane and 3-mercaptopropylmethyldimethoxysilane; isocyanate-type silane coupling agents such as 3-isocyanatetopropyltriethoxysilane; and acid anhydride-type silane coupling agents such as 3-trimethoxysilylpropylsuccinic anhydride. These may be used individually or in combination of two or more.

[0026] The functional groups contained in the above-mentioned silane coupling agents are preferably those that react with the substrate resin, in terms of improving adhesion and strength. In particular, epoxy-based silane coupling agents, unsaturated group-containing silane coupling agents, and amino-based silane coupling agents are preferred due to their high reactivity with thermosetting resins. Epoxy-based silane coupling agents and unsaturated group-containing silane coupling agents are more preferred, and 3-glycidoxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, and 8-methacryloxyoctyltrimethoxysilane are even more preferred. These can be used individually or in combination of two or more.

[0027] The first aqueous solution used in the present invention contains water, (i) a silane coupling agent, and (ii) a partially hydrolyzed product of component (i). The total amount of components (i) and (ii) is preferably 0.05 to 3% by mass, more preferably 0.1 to 2% by mass, and even more preferably 0.1 to 1.0% by mass, relative to the water. If it is less than 0.05% by mass, the affinity between the silane-treated glass cloth and the resin may not be obtained when producing the prepreg, which may adversely affect the reliability of the substrate. If it exceeds 3% by mass, the components of the first aqueous solution will thickly coat the surface of the glass cloth, which may reduce the adhesive strength between the matrix resin and the silane-treated glass cloth.

[0028] In the first aqueous solution used in the present invention, the content of component (i) is 30 to 95% by mass of the total of components (i) and (ii), preferably 40 to 90% by mass, more preferably 50 to 85% by mass, and even more preferably 65 to 85% by mass. Furthermore, the content of component (ii) is 5 to 70% by mass of the total of components (i) and (ii), preferably 10 to 60% by mass, more preferably 15 to 50% by mass, and even more preferably 15 to 45% by mass. The above content can be determined by gel permeation chromatography (GPC), and the measurement method is as described in the examples.

[0029] In addition to the above components, the first aqueous solution may also contain catalysts used in preparing the solution, alcohols produced as by-products by hydrolysis, etc.

[0030] (2) Second aqueous solution The second aqueous solution used in the present invention comprises (i) a silane coupling agent represented by the above general formula (1), (iii) an unfunctional organoxysilane represented by the following general formula (2), and (iv) a partial (co)hydrolyzed product of components (i) and (iii) (hereinafter, components (i), (iii), and (iv) are collectively referred to as "components of the second aqueous solution"). R 4 Z Si(OR 5 ) 4-Z (2)

[0031] (i) The silane coupling agent of component (i) is the same as that exemplified in the first aqueous solution, but epoxy-based silane coupling agents, unsaturated group-containing silane coupling agents and amino-based silane coupling agents are preferred due to their high reactivity with thermosetting resins, epoxy-based silane coupling agents and unsaturated group-containing silane coupling agents are more preferred, 3-glycidoxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 8-methacryloxyoctyltrimethoxysilane, and 3-aminopropyltrimethoxysilane are even more preferred, and methacrylic-based 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, and 8-methacryloxyoctyltrimethoxysilane are even more preferred.

[0032] (iii) The non-functional organoxysilane component is represented by formula (2) above, but in formula (2), R 4 R is a monovalent hydrocarbon group having 1 to 20 carbon atoms. 5 Z is a monovalent hydrocarbon group with 1 to 10 carbon atoms. Z is an integer from 1 to 3.

[0033] R 4The monovalent hydrocarbon group may be linear, branched, or cyclic, and examples include alkyl groups having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms; aryl groups having 6 to 20 carbon atoms, preferably 6 to 10 carbon atoms; and aralkyl groups having 7 to 20 carbon atoms, preferably 7 to 10 carbon atoms. R 4 A specific example of a monovalent hydrocarbon group is R 2 Examples of groups similar to those exemplified above include alkyl groups such as undecyl, dodecyl, and eicosyl groups; aryl groups such as naphthyl groups; and aralkyl groups such as benzyl and phenylethyl groups. Among these, R 4 The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms, and more preferably a methyl, ethyl, hexyl, or decyl group. R 5 As a monovalent hydrocarbon group, R 3 Examples of the same groups as those exemplified above include, among them, R 5 The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. Z is an integer between 1 and 3, but 1 or 2 is more preferred.

[0034] Specific examples of the non-functional organoxysilane component (iii) used in the present invention include alkyl group alkoxysilanes such as methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, trimethylethoxysilane, ethyltrimethoxysilane, diethyldimethoxysilane, triethylmethoxysilane, ethyltriethoxysilane, diethyldiethoxysilane, triethylethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, octyltrimethoxysilane, and octyltriethoxysilane; aryl group alkoxysilanes such as phenyltrimethoxysilane, diphenyldimethoxysilane, phenyltriethoxysilane, and methylphenyldimethoxysilane; and aralkyl alkoxysilanes such as benzyltrimethoxysilane and benzyltriethoxysilane. These may be used individually or in combination of two or more. Among these, alkyl group alkoxysilanes are preferred, methyltrimethoxysilane, dimethyldimethoxysilane, hexyltrimethoxysilane, and decyltrimethoxysilane are more preferred, methyltrimethoxysilane, hexyltrimethoxysilane, and decyltrimethoxysilane are even more preferred, and methyltrimethoxysilane, hexyltrimethoxysilane, and decyltrimethoxysilane are even more preferred.

[0035] While unfunctional organoxysilanes do not significantly improve adhesion, organoxysilanes containing alkyl or aryl groups with 20 or fewer carbon atoms impart hydrophobicity to the glass cloth surface. When silane-treated glass cloth is used on a wiring board, this prevents moisture from penetrating the substrate and thus prevents a decrease in dielectric loss tangent. Alkyl alkyl-containing alkoxysilanes are particularly preferred due to their excellent hydrophobicity-imparting effect. In this invention, a second aqueous solution combining a silane coupling agent and an unfunctional organoxysilane is more preferable from the standpoint of imparting hydrophobicity to the glass cloth.

[0036] The combination of (i) a silane coupling agent and (iii) an unfunctional organoxysilane used in the second aqueous solution is preferably (i) one or more selected from 3-glycidoxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-aminopropyltrimethoxysilane, and (iii) one or more selected from methyltrimethoxysilane, dimethyldimethoxysilane, hexyltrimethoxysilane, and decyltrimethoxysilane; more preferably (i) 3-methacryloxypropyltrimethoxysilane or 3-methacryloxypropyltriethoxysilane and (iii) one or more selected from methyltrimethoxysilane, hexyltrimethoxysilane, and decyltrimethoxysilane; and even more preferably (i) 3-methacryloxypropyltrimethoxysilane and (iii) methyltrimethoxysilane, hexyltrimethoxysilane, or decyltrimethoxysilane.

[0037] The second aqueous solution used in the present invention contains water, (i) a silane coupling agent, (iii) an unfunctional organoxysilane, and (iv) a partial (co)hydrolyzed product of components (i) and (iii), wherein the total amount of components (i), (iii), and (iv) is preferably 0.05 to 3% by mass, more preferably 0.1 to 2% by mass, and even more preferably 0.1 to 1.0% by mass, relative to water.

[0038] Furthermore, in the second aqueous solution used in the present invention, the total amount of components (i) and (iii) in the total of components (i), (iii), and (iv) is 30 to 95% by mass, and preferably 35 to 90% by mass. (iv) The content of component is 5 to 70% by mass, preferably 10 to 65% by mass, and more preferably 10 to 50% by mass. The above content can be determined by gel permeation chromatography (GPC), and the measurement method is as described in the examples.

[0039] In addition to the above components, the second aqueous solution may also contain catalysts used in preparing the solution, alcohols produced as by-products by hydrolysis, etc.

[0040] As described above, the first aqueous solution in the present invention contains component (ii) in an amount of 5 to 70% by mass of the total of components (i) and (ii). The second aqueous solution contains component (iv) in an amount of 5 to 70% by mass of the total of components (i), (iii), and (iv). With this content, the reaction between component (ii) or component (iv) and the Si-OH groups on the surface of the glass cloth proceeds easily, and the surface of the glass cloth can be uniformly treated with these components. If the content of component (ii) in the first aqueous solution or component (iv) in the second aqueous solution is less than 5% by mass, the condensation reactivity between the Si-OH groups on the glass cloth surface and component (ii) or (iv) will be poor, resulting in unreacted component (ii) or (iv), or a large amount of organoxy groups remaining after treatment, which will worsen the dielectric loss tangent.

[0041] In this invention, by treating glass cloth with an aqueous solution of organoxysilane that is highly reactive and provides low hygroscopicity, it is possible to realize silane-treated glass cloth and organic mounting substrates that are highly reliable and exhibit minimal degradation of dielectric properties even under high humidity.

[0042] [Method for preparing aqueous solutions] (1) Method for preparing the first aqueous solution The method for preparing the first aqueous solution used in the present invention is not particularly limited, but it is preferable to use a partial hydrolysis method. For example, (1-1) a method of partially hydrolyzing and condensing a silane coupling agent in water and obtaining the aqueous solution after the reaction is completed as the first aqueous solution (hereinafter referred to as "preparation method 1-1"), (1-2) a method of mixing a silane coupling agent that has been partially hydrolyzed and condensed in advance with water to obtain the first aqueous solution (hereinafter referred to as "preparation method 1-2").

[0043] (1-1) Preparation method 1-1 In preparation method 1-1, a first aqueous solution can be prepared by partially hydrolyzing and / or partially hydrolyzing and condensing the silane coupling agent in water. In the partial hydrolysis of the present invention, for example, by mixing the aforementioned silane coupling agents alone or two or more with water at room temperature (25°C), a first aqueous solution containing a silane derivative having hydroxyl groups and organoxy groups can be easily obtained. Hydrolysis generates hydroxyl groups, and their coexistence with organoxy groups improves wettability with the glass surface and provides excellent reactivity.

[0044] The amount of silane coupling agent added to water is not particularly limited, but is preferably 0.05 to 3% by mass, more preferably 0.1 to 2% by mass, and even more preferably 0.1 to 1.0% by mass.

[0045] When carrying out a hydrolysis-condensation reaction, it is preferable to use a hydrolysis-condensation catalyst. Conventional known catalysts can be used as hydrolysis and condensation catalysts, including, for example, acids such as hydrochloric acid, nitric acid, sulfuric acid, hydrogen halides, carboxylic acids, and sulfonic acids; acidic or weakly acidic inorganic salts; solid acids such as ion exchange resins; inorganic bases such as ammonia and sodium hydroxide; and organic bases such as tributylamine, 1,5-diazabicyclo[4.3.0]nonene-5 (DBN), and 1,8-diazabicyclo[5.4.0]undecene-7 (DBU). These may be used individually or in combination of two or more. Among these, those with a boiling point of 120°C or lower are preferred, carboxylic acids and ammonia are more preferred, and acetic acid and ammonia are even more preferred. When a catalyst is used, the amount used is not particularly limited, but 0.5 to 60 parts by mass, and more preferably 0.5 to 50 parts by mass, is preferred per 100 parts by mass of the silane coupling agent.

[0046] The hydrolysis reaction can be carried out without a solvent. In this case, the method of mixing the silane coupling agent with water is not particularly limited; the silane coupling agent may be added to water, or water may be added to the silane coupling agent. However, from the viewpoint of improving the reaction rate, it is preferable to add the silane coupling agent to water. When using a hydrolysis-condensation catalyst, it is preferable to use it mixed with water.

[0047] The hydrolysis reaction may be carried out in the presence of an organic solvent. The organic solvent is not particularly limited as long as it is compatible with each of the above starting compounds. Specific examples include aromatic hydrocarbons such as toluene and xylene; hydrocarbons such as hexane and octane; ketones such as methyl ethyl ketone and methyl isobutyl ketone; esters such as ethyl acetate and isobutyl acetate; and alcohols such as methanol, ethanol, isopropanol, butanol, isobutanol, and t-butanol. These may be used individually or in combination of two or more.

[0048] When using an organic solvent, the order in which the silane coupling agent, water, and solvent are added is arbitrary, but it is preferable to mix the mixture of the silane coupling agent and organic solvent with water. When using a catalyst, it may be added to the mixture of the silane coupling agent and solvent, or to water, but it is preferable to add it to water.

[0049] The reaction time during hydrolysis and condensation while stirring after adding the silane coupling agent to water is not particularly limited as long as the silane coupling agent is uniformly dispersed in the water. However, 30 minutes to 3 hours is preferred, and 30 minutes to 2 hours is more preferred, in order to allow sufficient hydrolysis of the silane coupling agent to proceed. Furthermore, the reaction temperature is preferably 10 to 60°C, and more preferably 20 to 50°C. Below 10°C, the hydrolysis reaction of the silane coupling agent may be slow, and above 60°C, the hydrolysis and condensation reactions may proceed excessively. The hydrolysis reaction proceeds when water and a silane coupling agent are mixed. After mixing, the reaction time—from immediate to slow—depends on the structure of the silane coupling agent.

[0050] After the reaction is complete, the by-product alcohol may be removed under reduced pressure or atmospheric pressure if necessary, but the aqueous solution after the reaction can be used as is without removing the alcohol.

[0051] (1-2) Preparation method 1-2 In preparation method 1-2, a silane coupling agent that has been partially hydrolyzed and condensed beforehand can be mixed with water to prepare a first aqueous solution.

[0052] The partial hydrolysis can be carried out in the same manner as in preparation method 1-1, but it is preferable to carry it out in the presence of an organic solvent, and more preferably in an organic solvent containing the amount of water necessary for hydrolysis. Specific examples of organic solvents are the same as those exemplified in preparation method 1-1, with aromatic hydrocarbons such as toluene and xylene being preferred, and toluene being more preferred. The ratio of water to organic solvent is not particularly limited, but 1 / 50 to 1 / 20 is preferred, and 1 / 30 to 1 / 20 is more preferred.

[0053] After the reaction is complete, it is preferable to wash the reaction product (partial hydrolysate) with water or the like to remove the by-products, alcohol, and solvent. The method of removing the solvent is not particularly limited, and any method can be used, but it is preferable to remove it by distillation under reduced pressure or atmospheric pressure. The first aqueous solution can be obtained by mixing the resulting reaction product with water. Note that the reaction product may also contain unreacted silane coupling agent.

[0054] (2) Method for preparing the second aqueous solution The method for preparing the second aqueous solution used in the present invention is not particularly limited, but it is preferable to use a partial hydrolysis method, similar to the method for preparing the first aqueous solution. Examples include (2-1) a method in which a silane coupling agent and an unfunctional organoxysilane are partially co-hydrolyzed and condensed in water, and the aqueous solution after the reaction is obtained as the second aqueous solution (hereinafter referred to as "preparation method 2-1"), and (2-2) a method in which a silane coupling agent and an unfunctional organoxysilane that have been partially co-hydrolyzed and condensed in advance are mixed in water to obtain the second aqueous solution (hereinafter referred to as "preparation method 2-2").

[0055] (2-1) Preparation method 2-1 In preparation method 2-1, a second aqueous solution can be prepared by partially co-hydrolyzing and / or partially co-hydrolyzing and / or condensing the silane coupling agent and the non-functional organoxysilane in water. In the present invention, a silane coupling agent having a reactive functional group is used in combination with alkylorganoxysilanes or arylorganoxysilanes that do not have a functional group. By reacting these with water, a second aqueous solution containing a silane derivative having both a functional group and a non-functional group, a hydrophobic group and a hydroxyl group, and an organoxy group can be obtained.

[0056] The second aqueous solution can be prepared under the same conditions as the first aqueous solution, using an unfunctional organoxysilane along with the silane coupling agent. The total amount of silane coupling agent and unfunctional organoxysila added to water is not particularly limited, but is preferably 0.05 to 3% by mass, more preferably 0.1 to 2% by mass, and even more preferably 0.1 to 1.0% by mass.

[0057] The amount of silane coupling agent added is 50 to 95% by mass of the total amount of the silane coupling agent and the unfunctional organoxysilane, with 50 to 91% by mass being preferred. The amount of unfunctional organoxysilane added to impart hydrophobicity is 5 to 50% by mass of the total amount of the silane coupling agent and unfunctional organoxysilane, with 9 to 50% by mass being preferable. If the amount is less than 5% by mass, the hydrophobicity of the silane-treated glass cloth will be insufficient, and if it exceeds 50% by mass, the wettability with the resin that acts as the binder of the silane-treated glass cloth will be insufficient, making it difficult to achieve sufficient strength.

[0058] (2-2) Preparation method 2-2 In preparation method 2-2, a second aqueous solution can be prepared by mixing a silane coupling agent or an unfunctional organoxysilane that has been partially co-hydrolyzed beforehand, or their partially co-hydrolyzed condensates, with water. In this case as well, a second aqueous solution can be obtained using a silane coupling agent and an unfunctional organoxysilane under the same conditions as in preparation method 1-2 for the first aqueous solution. The total amount of the silane coupling agent and the unfunctional organoxysilane added to water, and the proportion of each component, are the same as in preparation method 2-1.

[0059] [Method for manufacturing silane-treated glass cloth] The method for manufacturing silane-treated glass cloth is not particularly limited, but examples include methods that include the following steps. (a) Heat de-adhesion process in which the glass cloth is heated to any temperature between 300 and 1000°C to remove the adhesive. (b) If necessary, a fiber opening process for opening the glass yarn of the glass cloth. (c) A coating step in which a component of the first aqueous solution or a component of the second aqueous solution is applied to the surface of the glass cloth. (d) A fixing step in which the components of the first aqueous solution or the components of the second aqueous solution attached to the surface of the glass cloth are fixed to the surface of the glass cloth by heating and drying.

[0060] It is believed that the above manufacturing method makes it possible to form a layer of either the component of the first aqueous solution or the component of the second aqueous solution almost completely and uniformly on the entire surface of each individual glass yarn constituting the glass cloth.

[0061] (a) Heating desizing process In the heat de-adhesion process, the glass cloth is heated to an arbitrary temperature between 300 and 1000°C to remove sizing agents and other substances adhering to the surface of the glass cloth. Sizing agents and other substances adhere to the surface of woven glass cloth, and if left untreated, the dielectric properties may deteriorate due to the remaining sizing agents. In addition, insufficient silane treatment of the glass cloth may result in poor adhesion with the resin when used in prepregs. Therefore, it is preferable to heat-treat the glass cloth after weaving to remove the adhering sizing agents.

[0062] The heating method is not particularly limited, and conventionally known methods can be used, but heat cleaning is common. The heat cleaning method is also not particularly limited, and conventionally known methods can be used, such as a batch method in which organic matter is slowly burned and removed at 300-400°C.

[0063] (b) Opening process In the fiber opening process, the glass yarn of the glass cloth is opened as needed. The glass cloth obtained by weaving can be used as is, but if necessary, it can be subjected to a fiber-opening treatment to improve the impregnation of resin solutions, etc., when used in prepregs, and to improve the surface smoothness. The fiber-opening treatment method is not particularly limited, but examples include methods using ultrasound, high-pressure water, diffusion spray, gas-liquid mixed mist, etc.

[0064] (c) Covering process In the coating process, components of the first aqueous solution or components of the second aqueous solution are applied to the surface of the glass cloth. The method for attaching the components of the first aqueous solution or the second aqueous solution to the surface of the glass cloth is not particularly limited and can be appropriately selected from conventionally known methods. Conventionally known methods are generally broadly classified into two types: coating methods and immersion methods. Immersion methods include methods in which the glass cloth is immersed in an aqueous solution, while coating methods include coating by roll coating, etc. Among these, the method of immersing the glass cloth in an aqueous solution is preferred.

[0065] (d) Fixing process In the fixing process, the condensation reaction between the components of the first aqueous solution or the components of the second aqueous solution attached to the glass cloth and the Si-OH groups on the surface of the glass cloth is carried out by heating and drying, thereby fixing the above components to the surface of the glass cloth. There are no particular restrictions on the heating method, but examples include hot air drying, infrared heating, and heating by hot rolling. The heating temperature is preferably 80 to 180°C, and more preferably 90 to 130°C. If the heating temperature is below 80°C, not only will the reaction of the above components not proceed, but water, alcohol produced by condensation, and in some cases the hydrolysis / condensation catalyst used may not volatilize. Also, if the temperature exceeds 180°C, the reaction of organoxysilane proceeds rapidly, and uniform silane treatment may not be possible.

[0066] The amount of the component of the first aqueous solution or the component of the second aqueous solution adhering to the glass cloth after silane treatment is 0.08% by mass or less, preferably 0.03 to 0.07% by mass, and more preferably 0.03 to 0.06% by mass. If it exceeds 0.08% by mass, the amount of adhesion to the glass cloth becomes excessive and worsens the dielectric loss tangent. The above adhesion amount can be calculated from the ignition loss described in JIS R 3420. Furthermore, the dielectric loss tangent of the silane-treated glass cloth of the present invention at 40 GHz is preferably 0.0015 or less, more preferably 0.0010 or less, and even more preferably 0.0005 or less, after heat treatment at 150°C for 3 minutes. It is also preferable that the dielectric loss tangent at 40 GHz after being left in an atmosphere of 25°C / 80%RH for 100 hours is the same as described above.

[0067] [2] Prepreg The prepreg of the present invention comprises the silane-treated glass cloth described above and a matrix resin impregnated into the silane-treated glass cloth. The prepreg of the present invention (hereinafter also referred to as "silane-treated glass cloth-containing prepreg") provides a highly reliable printed circuit board with excellent adhesion and bonding properties between the silane-treated glass cloth and the matrix resin, improved strength, and excellent dielectric properties, particularly dielectric properties under high temperature and high humidity conditions.

[0068] [Silane-treated glass cloth] The prepreg of the present invention uses the silane-treated glass cloth described above. The glass cloth treated with the above-described organoxysilane aqueous solution is suitably used to impregnate with a matrix resin to produce a prepreg.

[0069] [Matrix resin] The matrix resin used in this invention is impregnated into the silane-treated glass cloth described above to form a prepreg, and either a thermosetting resin or a thermoplastic resin can be used. To manufacture prepregs for high-frequency substrates with excellent dielectric properties, it is preferable that the matrix resin also has excellent dielectric properties. Therefore, resins with low dielectric properties are preferred as the matrix resin. Specific examples include epoxy resins, silicone resins, polyimide resins, bismaleimide resins, polyphenylene ether resins, and polytetrafluoroethylene resins. These can be used individually or in combination of two or more. In particular, the bismaleimide resin represented by the following general formula (3) is suitable for use as a matrix resin for low-dielectric substrates due to its excellent adhesion, processability, and low dielectric loss tangent characteristics.

[0070] [ka]

[0071] In the above formula, A independently represents a tetravalent organic group containing an aromatic ring or an aliphatic ring. B is an alkylene group having 6 to 18 carbon atoms and having an aliphatic ring which may contain a divalent heteroatom. Q independently represents a linear alkylene group or linear alkenylene group having 6 or more carbon atoms. R independently represents a linear or branched alkyl group having 6 or more carbon atoms. n represents a number from 1 to 10. m represents a number from 0 to 10.

[0072] Specific examples of the tetravalent organic group of A include, but are not limited to, the following. [ka] (In the formula, * indicates the bond position with a carbon atom.)

[0073] Specific examples of the alkylene group of B include, but are not limited to, the following. [ka] (In the formula, · indicates the bond position with the nitrogen atom.)

[0074] Specific examples of Q include straight-chain alkylene groups such as n-hexylene, n-heptylene, n-octylene, n-nonylene, and n-decamethylene; and straight-chain alkenylene groups such as hexenylene, heptenylene, and octenylene. Specific examples of alkyl groups R include hexyl, heptyl, octyl, nonyl, decyl, undecyl, lauryl, stearyl, isohexyl, isooctyl groups, and their structural isomers.

[0075] Specific examples of bismaleimide resins include the SLK-2000 series (manufactured by Shin-Etsu Chemical Co., Ltd.), SLK-6895 (manufactured by Shin-Etsu Chemical Co., Ltd.), and SLK-3000 (manufactured by Shin-Etsu Chemical Co., Ltd.). In addition to bismaleimide resins, thermosetting cyclopentadiene-styrene copolymer resins can also be used as high-heat-resistant resins. A specific example is the SLK-250 series (manufactured by Shin-Etsu Chemical Co., Ltd.). Furthermore, the matrix resin may be used alone, or two or more resins may be used in combination. Among these, SLK-3000 (manufactured by Shin-Etsu Chemical Co., Ltd.), represented by the following formula, is preferred.

[0076] [ka] (In the formula, n ≈ 3 (mean value).)

[0077] Furthermore, other components may be added to the matrix resin used in this invention to accelerate resin curing, increase strength, and for other purposes. Specific examples of other components include inorganic fillers, flame retardants, additives, and reaction initiators. When other components are added, the amount added is preferably 1 to 900 parts by mass, and more preferably 10 to 500 parts by mass, per 100 parts by mass of the matrix resin.

[0078] [Prepreg manufacturing method] The method for producing the prepreg containing the silane-treated glass cloth of the present invention is not particularly limited, and general methods for producing glass cloth-containing substrates, films, prepregs, etc., can be applied. For example, it can be produced in accordance with a general method for applying a curable resin composition to glass cloth (coating method).

[0079] Specific examples of coating methods include direct gravure coaters, chamber doctor coaters, offset gravure coaters, single-roll kiss coaters, reverse kiss coaters, bar coaters, reverse roll coaters, slotter dies, air doctor coaters, forward-rotating roll coaters, blade coaters, knife coaters, impregnation coaters, MB coaters, MB reverse coaters, and the like.

[0080] To improve and ensure coatability, the matrix resin may be diluted with a solvent. Due to the solubility characteristics of the matrix resin, one organic solvent can be used alone or a mixture of two or more. Specific examples of organic solvents include aliphatic alcohols such as methanol, ethanol, isopropanol, and n-butanol; aliphatic ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; glycol ethers such as ethylene glycol and propylene glycol; aliphatic hydrocarbons such as hexane and heptane; aromatic hydrocarbons such as toluene and xylene; and alkyl ethers such as diethyl ether, diisopropyl ether, and dibutyl ether.

[0081] The amount of matrix resin adhering to the silane-treated glass cloth of the present invention is preferably 10 to 80% by mass, and more preferably 20 to 70% by mass. Within this range, the amount of matrix resin adhering to the silane-treated glass cloth of the present invention is more appropriate, and has the effect of improving the adhesion, bonding, and strength of the wiring board between the silane-treated glass cloth and the matrix resin. If the adhering amount is 10% by mass or more, when a printed wiring board is manufactured from the prepreg, the amount of matrix resin adhering to the copper foil is not too little, and sufficient peel strength between the copper foil and the matrix resin is obtained. Furthermore, if the adhering amount is 80% by mass or less, the amount of matrix resin is not too much, and resin flow during pressing is less likely to occur, which is preferable. Here, the adhering amount refers to the ratio (mass%) of matrix resin to the total mass of the prepreg.

[0082] Post-coating treatment methods vary depending on the matrix resin used, but one example is drying the coating and then heating it at 50-300°C for 1 minute to 24 hours for curing purposes.

[0083] [3] Printed circuit board The printed circuit board of the present invention comprises the prepreg described above. The printed circuit board of the present invention (hereinafter also referred to as the "silane-treated glass cloth-containing printed circuit board") has excellent dielectric properties and can be suitably used in electronic components having circuits that transmit electrical signals of 10 GHz or higher.

[0084] [Manufacturing method for printed circuit boards] The printed circuit board of the present invention can be manufactured, for example, by laminating one or more, preferably 2 to 20, of the silane-treated glass cloth-containing prepregs described above and then heat-curing them. The heat curing conditions are not particularly limited, but for example, heating may be performed at 100 to 250°C for 1 to 600 minutes, and if necessary, a pressure of 0.1 to 20 MPa may be applied simultaneously with the heating. [Examples]

[0085] The present invention will be specifically described below with reference to preparation examples, examples, and comparative examples, but the present invention is not limited to the following examples.

[0086] [1] Method for measuring physical properties The content of organoxysilane, its partial hydrolysates, and partial (co)hydrolysates in the organoxysilane aqueous solution, the dielectric loss tangent of the silane-treated glass cloth, the loss on ignition, and the dielectric loss tangent of the substrate were measured according to the following methods.

[0087] (1) Method for measuring the content of organoxysilane, its partial hydrolysate, and partial (co) hydrolysate in an aqueous solution of organoxysilane The content of organoxysilane, its partial hydrolysate, and partial (co)hydrolysate in aqueous solutions of organoxysilane for glass cloth treatment was determined using polystyrene of known molecular weight as a standard sample by gel permeation chromatography (GPC) measured under the following conditions. [Measurement conditions] Developing solvent: Tetrahydrofuran (THF) Flow rate: 0.6mL / min Detector: Differential refractive index detector (RI) Column: TSK Guardcolumn SuperH-H TSKgel SuperHM-N(6.0mmI.D.×15cm×1) TSKgel SuperH2500(6.0mmI.D.×15cm×1) (All manufactured by Tosoh Corporation) Column temperature: 40℃ Sample injection volume: 50 μL (THF solution with a concentration of 2.0% by mass) (2) Dielectric loss tangent of silane-treated glass cloth The dielectric loss tangent of silane-treated glass cloth was measured using a Split post dielectric resonator (SPDR) with a dielectric resonator frequency of 40 GHz (manufactured by Keysight Technologies, Inc.). The results are shown in Tables 1-3. (3)Ignition loss The measurements were taken in accordance with the method described in JIS R 3420, 7.3.2. The results are shown in Tables 1-3. The amount of silane-treated glass cloth that can be processed by the organoxysilane aqueous solution component can be determined by the loss on ignition. (4) Dielectric loss tangent of the substrate The dielectric loss tangent of the resin substrate immediately after fabrication (substrate dielectric loss tangent -1) and the dielectric loss tangent of the substrate after being left for 100 hours in an atmosphere of 25°C / 80%RH (substrate dielectric loss tangent -2) were measured using the same apparatus as described above. The results are shown in Tables 1-3.

[0088] [2] Preparation of matrix resin [Preparation Example 1] The matrix resin used to prepare the prepreg was prepared as follows. A mixture was prepared by adding 122 parts by mass of toluene to 100 parts by mass of bismaleimide resin (SLK-3000; trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) to adjust the resin concentration to 45% by mass. Then, 2 parts by mass of dicumyl peroxide was added as a curing catalyst to prepare an impregnation matrix resin.

[0089] [3] Manufacturing and evaluation of silane-treated glass cloth [Example 1-1] To 100 parts by mass of distilled water, aqueous ammonia (ammonia concentration 28% by mass) was added as a hydrolysis / condensation catalyst to prepare an aqueous solution for hydrolysis, so that the amount of ammonia in the aqueous solution was 0.1 parts by mass. To 100 parts by mass of this aqueous solution for hydrolysis, 0.2 parts by mass of 3-methacryloxypropyltrimethoxysilane and 0.05 parts by mass of methyltrimethoxysilane were added dropwise, and the mixture was stirred at 25°C for 60 minutes to prepare alkoxysilane aqueous solution-1 for glass cloth treatment. In this aqueous solution, the ratio of silane monomers (unhydrolyzed; the same applies hereinafter) to their partial (co)hydrolyzed products was 66% by mass of silane monomers (total of 3-methacryloxypropyltrimethoxysilane and methyltrimethoxysilane) and 34% by mass of their partial (co)hydrolyzed products, according to GPC. The amount of unfunctionalized alkoxysilane mixed in was 20.0% by mass. Alkoxysilane aqueous solution-1 with quartz glass cloth (IPC standard 1078 plain weave, basis weight 42.5 g / m²) 2 After immersion in a dielectric loss tangent (10 GHz) of 0.0006, the silane-treated quartz glass cloth-1 was prepared by passing it through a 150-micron gap roll to remove excess treatment solution, and then heat-treating it in a forced-air circulating dryer at 150°C for 3 minutes. The ignition loss of this silane-treated quartz glass cloth was 0.04 mass%. The dielectric loss tangent of this silane-treated quartz glass cloth-1 was measured.

[0090] [Examples 1-2] Aqueous alkoxysilane aqueous solution-2 for glass cloth treatment was prepared in the same manner as in Example 1-1, except that 3-methacryloxypropyltrimethoxysilane was replaced with 3-aminopropyltrimethoxysilane, in combination with methyltrimethoxysilane. The ratio of silane monomer and its partial (co)hydrolysate in this aqueous solution was 58% by mass of silane monomer (total of 3-aminopropyltrimethoxysilane and methyltrimethoxysilane) and 42% by mass of its partial (co)hydrolysate, according to GPC. Using aqueous alkoxysilane solution-2, silane-treated quartz glass cloth-2 was prepared in the same manner as in Example 1-1, and the dielectric loss tangent was measured. The ignition loss of this silane-treated quartz glass cloth was 0.05 mass%.

[0091] [Examples 1-3] An aqueous solution of alkoxysilane for glass cloth treatment-3 was prepared in the same manner as in Example 1-1, except that 0.1 parts by mass of ammonia in the hydrolysis-condensation catalyst of Example 1-1 was replaced with 0.1 parts by mass of acetic acid. The ratio of silane monomer and its partial (co)hydrolyzed product in this aqueous solution was 65% by mass of silane monomer (total of 3-methacryloxypropyltrimethoxysilane and methyltrimethoxysilane) and 35% by mass of its partial (co)hydrolyzed product, according to GPC. Using an aqueous solution of alkoxysilane-3, silane-treated quartz glass cloth-3 was prepared in the same manner as in Example 1-1, and the dielectric loss tangent was measured. The ignition loss of this silane-treated quartz glass cloth was 0.04 mass%.

[0092] [Examples 1-4] Alkoxysilane aqueous solution-4 for glass cloth treatment was prepared in the same manner as in Example 1-1, except that the amount of methyltrimethoxysilane added was 0.02 parts by mass. The ratio of silane monomer and its partial (co)hydrolyzed product in this aqueous solution was 85% by mass of silane monomer (total of 3-methacryloxypropyltrimethoxysilane and methyltrimethoxysilane) and 15% by mass of its partial (co)hydrolyzed product, according to GPC. Using an aqueous solution of alkoxysilane-4, a silane-treated quartz glass cloth-4 was prepared in the same manner as in Example 1-1, and its dielectric loss tangent was measured. The ignition loss of this silane-treated quartz glass cloth was 0.03% by mass.

[0093] [Examples 1-5] Alkoxysilane aqueous solution-5 for glass cloth treatment was prepared in the same manner as in Example 1-1, except that the amount of methyltrimethoxysilane added was 0.2 parts by mass. The ratio of silane monomer and its partial (co)hydrolyzed product in this aqueous solution was 56% by mass of silane monomer (total of 3-methacryloxypropyltrimethoxysilane and methyltrimethoxysilane) and 44% by mass of its partial (co)hydrolyzed product, according to GPC. Using an aqueous solution of alkoxysilane-5, a silane-treated quartz glass cloth-5 was prepared in the same manner as in Example 1-1, and its dielectric loss tangent was measured. The ignition loss of this silane-treated quartz glass cloth was 0.07% by mass.

[0094] [Examples 1-6] Alkoxysilane aqueous solution-6 for glass cloth treatment was prepared in the same manner as in Example 1-1, except that methyltrimethoxysilane was replaced with hexyltrimethoxysilane. The ratio of silane monomer and its partial (co)hydrolyzed product in this aqueous solution was 80% by mass of silane monomer (total of 3-methacryloxypropyltrimethoxysilane and hexyltrimethoxysilane) and 20% by mass of its partial (co)hydrolyzed product, as measured by GPC. Silane-treated quartz glass cloth-6 was prepared using alkoxysilane aqueous solution-6 in the same manner as in Example 1-1, and the dielectric loss tangent was measured. The ignition loss of this silane-treated quartz glass cloth was 0.04% by mass.

[0095] [Examples 1-7] Alkoxysilane aqueous solution-7 for glass cloth treatment was prepared in the same manner as in Example 1-1, except that methyltrimethoxysilane was replaced with decyltrimethoxysilane. The ratio of silane monomer and its partial (co)hydrolyzed product in this aqueous solution was 88% by mass of silane monomer (total of 3-methacryloxypropyltrimethoxysilane and decyltrimethoxysilane) and 12% by mass of its partial (co)hydrolyzed product, according to GPC. Using an aqueous solution of alkoxysilane-7, silane-treated quartz glass cloth-7 was prepared in the same manner as in Example 1-1, and the dielectric loss tangent was measured. The ignition loss of this silane-treated quartz glass cloth was 0.05% by mass.

[0096] [Examples 1-8] Alkoxysilane aqueous solution-8 for glass cloth treatment was prepared in the same manner as in Example 1-1, except that 0.05 parts by mass of methyltrimethoxysilane was replaced with 0.1 parts by mass of dimethyldimethoxysilane. The ratio of silane monomer and its partial (co)hydrolysate in this aqueous solution was 52% by mass of silane monomer (total of 3-methacryloxypropyltrimethoxysilane and dimethyldimethoxysilane) and 48% by mass of its partial (co)hydrolysate, according to GPC. Silane-treated quartz glass cloth-8 was prepared using alkoxysilane aqueous solution-8 in the same manner as in Example 1-1, and the dielectric loss tangent was measured. The ignition loss of this silane-treated quartz glass cloth was 0.07 mass%.

[0097] [Examples 1-9] To the same hydrolysis aqueous solution as in Example 1-1, 0.2 parts by mass of 3-glycidoxypropyltrimethoxysilane and 0.05 parts by mass of methyltrimethoxysilane were added dropwise, and the mixture was stirred at 25°C for 60 minutes to prepare alkoxysilane aqueous solution-9 for glass cloth treatment. In this aqueous solution, the ratio of silane monomer to its partial (co)hydrolyzed product, as measured by GPC, was 35% by mass of silane monomer (total of 3-glycidoxypropyltrimethoxysilane and methyltrimethoxysilane) and 65% by mass of its partial (co)hydrolyzed product. A silane-treated quartz glass cloth-9 was prepared using an aqueous alkoxysilane solution-9 in the same manner as in Example 1-1, and its dielectric loss tangent was measured. The ignition loss of this silane-treated quartz glass cloth was 0.06% by mass.

[0098] [Examples 1-10] Aqueous solution of alkoxysilane for glass cloth treatment-10 was prepared by adding 0.1 parts by mass of 3-methacryloxypropyltrimethoxysilane, 0.1 parts by mass of 3-glycidoxypropyltrimethoxysilane, and 0.05 parts by mass of methyltrimethoxysilane to 100 parts by mass of distilled water and stirring at 25°C for 30 minutes. The ratio of silane monomer and its partial (co)hydrolyzed product in this aqueous solution was 90% by mass of silane monomer (total of 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and methyltrimethoxysilane) and 10% by mass of its partial (co)hydrolyzed product, according to GPC. Silane-treated quartz glass cloth-10 was prepared using alkoxysilane aqueous solution-10 in the same manner as in Example 1-1, and the dielectric loss tangent was measured. The ignition loss of this silane-treated quartz glass cloth was 0.06 mass%.

[0099] [Examples 1-11] Similar to Examples 1-10, 0.2 parts by mass of 3-glycidoxypropyltrimethoxysilane was added to 100 parts by mass of distilled water and stirred at 25°C for 30 minutes to prepare alkoxysilane aqueous solution-11 for glass cloth treatment. In this aqueous solution, the ratio of silane monomer to its partial hydrolysate, as measured by GPC, was 85% by mass of silane monomer (3-glycidoxypropyltrimethoxysilane) and 15% by mass of its partial hydrolysate. Silane-treated quartz glass cloth-11 was prepared using alkoxysilane aqueous solution-11 in the same manner as in Example 1-1, and the dielectric loss tangent was measured. The ignition loss of this silane-treated quartz glass cloth was 0.07% by mass.

[0100] [Examples 1-12] A 1,000 mL separable flask equipped with a stirrer, reflux condenser, dropping funnel, and thermometer contained a mixture of 248.4 g (1 mol) of 3-methacryloxypropyltrimethoxysilane and 62.7 g (0.46 mol) of methyltrimethoxysilane, along with 311.1 g of toluene. While stirring, 19.9 g of an aqueous hydrolysis solution (18 g of distilled water in which 1.9 g of glacial acetic acid was dissolved) was added dropwise over 10 minutes. After the addition was complete, the mixture was reacted at 25°C for 2 hours. The mixture was then washed three times with distilled water to remove the acetic acid, and the remaining methanol, acetic acid, and toluene were removed by vacuum distillation to obtain hydrolyzed alkoxysilane-1. Hydrolyzed alkoxysilane-1 was added in 0.25 parts by mass to 100 parts by mass of distilled water to prepare an aqueous solution of alkoxysilane-12 for glass cloth treatment. In this aqueous solution, the ratio of silane monomer to its partial (co)hydrolyzed product was 60% by mass of silane monomer (total of 3-methacryloxypropyltrimethoxysilane and methyltrimethoxysilane) and 40% by mass of its partial (co)hydrolyzed product, according to GPC. Furthermore, the unfunctionalized alkoxysilane content of hydrolyzed alkoxysilane-1 was 20% by mass. Silane-treated quartz glass cloth-12 was prepared in the same manner as in Example 1-1, except that aqueous solution alkoxysilane-1 for glass cloth treatment in Example 1-1 was replaced with aqueous solution alkoxysilane-12 for glass cloth treatment, and the dielectric loss tangent was measured. The ignition loss of this silane-treated quartz glass cloth was 0.08 mass%.

[0101] [Examples 1-13] The mixed system of 248.4 g (1 mol) of 3-methacryloxypropyltrimethoxysilane and 62.7 g (0.46 mol) of methyltrimethoxysilane in Examples 1-12 was changed to a system of 248.4 g of 3-methacryloxypropyltrimethoxysilane alone. In the same manner as in Examples 1-12, 248.4 g of toluene was added, and while stirring, 19.9 g of an aqueous hydrolysis solution (18 g of distilled water in which 1.9 g of glacial acetic acid was dissolved) was added dropwise over 10 minutes. After the addition was complete, the mixture was reacted at 25°C for 2 hours. Next, the mixture was washed three times with distilled water to remove the acetic acid, and the remaining methanol, acetic acid, and toluene were removed by vacuum distillation to obtain hydrolyzed alkoxysilane-2. Hydrolyzed alkoxysilane-2 was added in 0.2 parts by mass to 100 parts by mass of distilled water to prepare an aqueous solution of alkoxysilane-13 for glass cloth treatment. The ratio of the silane monomer and its partial hydrolysate in this aqueous solution, as measured by GPC, was 55% by mass of the silane monomer (3-methacryloxypropyltrimethoxysilane) and 45% by mass of its partial hydrolysate. Silane-treated quartz glass cloth-13 was prepared in the same manner as in Example 1-1, except that aqueous solution alkoxysilane-1 for glass cloth treatment in Example 1-1 was replaced with aqueous solution alkoxysilane-13 for glass cloth treatment, and the dielectric loss tangent was measured. The ignition loss of this silane-treated quartz glass cloth was 0.08% by mass.

[0102] [Comparative Example 1-1] An aqueous solution of alkoxysilane for glass cloth treatment-14 was prepared by adding 0.2 parts by mass of 3-methacryloxypropyltrimethoxysilane to 100 parts by mass of distilled water and stirring at 25°C for 5 minutes to disperse the mixture. The ratio of the silane monomer to its partial hydrolysate in this aqueous solution was 100% by mass of the silane monomer (3-methacryloxypropyltrimethoxysilane) as measured by GPC. Silane-treated quartz glass cloth-14 was prepared using alkoxysilane aqueous solution-14 in the same manner as in Example 1-1, and the dielectric loss tangent was measured. The ignition loss of this silane-treated quartz glass cloth was 0.08% by mass.

[0103] [Comparative Example 1-2] A glass cloth treatment aqueous solution-15 of alkoxysilane was prepared by adding 0.2 parts by mass of 3-methacryloxypropyltrimethoxysilane to 100 parts by mass of the hydrolysis aqueous solution of Example 1-1 and stirring at 60°C for 3 hours to disperse the mixture. The ratio of the silane monomer and its partial hydrolysate in this aqueous solution, as measured by GPC, was 10% by mass of the silane monomer (3-methacryloxypropyltrimethoxysilane) and 90% by mass of its partial hydrolysate. Silane-treated quartz glass cloth-15 was prepared using alkoxysilane aqueous solution-15 in the same manner as in Example 1-1, and the dielectric loss tangent was measured. The ignition loss of this silane-treated quartz glass cloth was 0.15% by mass.

[0104] [Comparative Examples 1-3] Alkoxysilane aqueous solution-16 for glass cloth treatment was prepared by adding 0.05 parts by mass of 3-methacryloxypropyltrimethoxysilane and 0.2 parts by mass of methyltrimethoxysilane to 100 parts by mass of the hydrolysis aqueous solution of Example 1-1 and stirring at 25°C for 5 minutes to disperse the mixture. The ratio of silane monomer to its partial (co)hydrolyzed product in this aqueous solution was 100% by mass of silane monomer (total of 3-methacryloxypropyltrimethoxysilane and methyltrimethoxysilane) as measured by GPC. The unfunctionalized alkoxysilane content of alkoxysilane aqueous solution-16 was 80% by mass. Silane-treated quartz glass cloth-16 was prepared using alkoxysilane aqueous solution-16 in the same manner as in Example 1-1, and the dielectric loss tangent was measured. The ignition loss of this silane-treated quartz glass cloth was 0.10% by mass.

[0105] [Comparative Examples 1-4] Alkoxysilane aqueous solution-17 for glass cloth treatment was prepared by adding 0.08 parts by mass of hydrolyzed alkoxysilane-2 prepared in Example 1-13 and 0.18 parts by mass of methyltrimethoxysilane to 100 parts by mass of the hydrolysis aqueous solution of Example 1-1, and stirring at 25°C for 60 minutes to disperse the mixture. The ratio of silane monomer to its partial (co)hydrolyzed product in this aqueous solution, as measured by GPC, was 70% by mass of silane monomer (total of 3-methacryloxypropyltrimethoxysilane and methyltrimethoxysilane) and 30% by mass of its partial (co)hydrolyzed product. The unfunctionalized alkoxysilane content of alkoxysilane aqueous solution-17 was 69.2% by mass. Silane-treated quartz glass cloth-17 was prepared using alkoxysilane aqueous solution-17 in the same manner as in Example 1-1, and the dielectric loss tangent was measured. The ignition loss of this silane-treated quartz glass cloth was 0.11% by mass.

[0106] [Comparative Examples 1-5] To prepare alkoxysilane aqueous solution-18 for glass cloth treatment, 100 parts by mass of the hydrolysis aqueous solution of Example 1-1 was mixed with 0.18 parts by mass of partially hydrolyzed alkoxysilane-2 prepared in Example 1-13, 0.05 parts by mass of 3-methacryloxypropyltrimethoxysilane, and 0.02 parts by mass of methyltrimethoxysilane. The mixture was then stirred at 25°C for 60 minutes to disperse the mixture. In this aqueous solution, the ratio of silane monomer to its partial (co)hydrolyzed product, as measured by GPC, was 25% by mass of silane monomer (total of 3-methacryloxypropyltrimethoxysilane and methyltrimethoxysilane) and 75% by mass of its partial (co)hydrolyzed product. Furthermore, the unfunctionalized alkoxysilane content of aqueous solution alkoxysilane-18 was 8.0% by mass. Silane-treated quartz glass cloth-18 was prepared using alkoxysilane aqueous solution-18 in the same manner as in Example 1-1, and the dielectric loss tangent was measured. The ignition loss of this silane-treated quartz glass cloth was 0.12% by mass.

[0107] [4] Manufacturing and evaluation of resin substrates [Examples 2-1 to 2-13, Comparative Examples 2-1 to 2-5] The silane-treated quartz glass cloths-1 to 18 obtained in Examples 1-1 to 1-13 and Comparative Examples 1-1 to 1-5 were impregnated with the matrix resin prepared in Preparation Example 1, and the solvent was removed by heating and drying at 120°C for 5 minutes to prepare prepregs. At that time, the amount of resin attached was adjusted to 44% by mass. Subsequently, three layers of each fabricated prepreg were stacked and cured using a vacuum press at a pressure of 5 MPa under step curing conditions of 150°C / 1 hour and then 180°C / 2 hours to produce a resin substrate. The dielectric loss tangent of this resin substrate was then measured.

[0108] [Table 1] *1 Silane coupling agent *2 Unfunctionalized alkoxysilane KBM-503: 3-Methacryloxypropyltrimethoxysilane KBM-903: 3-aminopropyltrimethoxysilane KBM-403:3-Glycidoxypropyltrimethoxysilane KBM-13: Methyltrimethoxysilane KBM-22: Dimethyldimethoxysilane KBM-3063: Hexyltrimethoxysilane KBM-3103C: Decyltrimethoxysilane Hydrolyzed alkoxysilane - 1:3-methacryloxypropyltrimethoxysilane and methyltrimethoxysilane mixture Hydrolyzed alkoxysilane-2:3-methacryloxypropyltrimethoxysilane monosystem

[0109] [Table 2] *1 Silane coupling agent *2 Unfunctionalized alkoxysilane KBM-503: 3-Methacryloxypropyltrimethoxysilane KBM-903: 3-aminopropyltrimethoxysilane KBM-403:3-Glycidoxypropyltrimethoxysilane KBM-13: Methyltrimethoxysilane KBM-22: Dimethyldimethoxysilane KBM-3063: Hexyltrimethoxysilane KBM-3103C: Decyltrimethoxysilane Hydrolyzed alkoxysilane - 1:3-methacryloxypropyltrimethoxysilane and methyltrimethoxysilane mixture Hydrolyzed alkoxysilane-2:3-methacryloxypropyltrimethoxysilane monosystem

[0110] [Table 3] *1 Silane coupling agent *2 Unfunctionalized alkoxysilane KBM-503: 3-Methacryloxypropyltrimethoxysilane KBM-903: 3-aminopropyltrimethoxysilane KBM-403:3-Glycidoxypropyltrimethoxysilane KBM-13: Methyltrimethoxysilane KBM-22: Dimethyldimethoxysilane KBM-3063: Hexyltrimethoxysilane KBM-3103C: Decyltrimethoxysilane Hydrolyzed alkoxysilane - 1:3-methacryloxypropyltrimethoxysilane and methyltrimethoxysilane mixture Hydrolyzed alkoxysilane-2:3-methacryloxypropyltrimethoxysilane monosystem

Claims

1. (i) One or more organoxysilanes represented by the following general formula (1), (ii) Partial hydrolysate of component (i) and It contains, A silane-treated glass cloth is surface-treated by heating at 80 to 180°C, to which an aqueous organooxysilane solution is attached, wherein the total content of components (i) is 30 to 95% by mass and the content of component (ii) is 5 to 70% by mass of components (i) and (ii), and the glass cloth is surface-treated with this solution, and the loss on ignition is 0.08% by mass or less. R 1 X R 2 Y Si(OR 3 ) 4-X-Y (1) (In the formula, R 1 is a monovalent organic group having 1 to 20 carbon atoms containing an epoxy group, an amino group, an unsaturated group, a mercapto group, an isocyanate group, an acid anhydride group or a hydroxyl group, R 2 is an alkyl group or an aryl group having 1 to 10 carbon atoms, R 3 is a monovalent hydrocarbon group having 1 to 10 carbon atoms, X is 1 or 2, Y is 0 or 1, and X + Y is 1 or 2.) The glass cloth described above is a silane-treated glass cloth having a plain weave structure in which glass yarn, made by bundling 30 to 250 glass filaments having an SiO2 composition of 45 to 100% by mass and an average filament diameter of 3 to 20 μm, is used as the warp and weft threads, and the weft and warp threads are woven at an independent density of 10 to 140 threads / inch, and the basis weight of the glass cloth is 8 to 250 g / m².

2. (i) One or more organoxysilanes represented by the following general formula (1), (iii) One or more organoxysilanes represented by the following general formula (2), (iv) A partial (co)hydrolyzed product of component (i) 50-95% by mass and component (iii) 5-50% by mass It contains, A silane-treated glass cloth is surface-treated by heating at 80 to 180°C, wherein the total content of components (i) and (iii) is 30 to 95% by mass, and the total content of component (iv) is 5 to 70% by mass, and the glass cloth to which an aqueous organooxysilane solution has been attached is heated. The glass cloth is surface-treated, and the loss on ignition is 0.08% by mass or less. R 1 X R 2 Y Si(OR 3 ) 4-X-Y (1) (In the formula, R 1 R is a monovalent organic group having 1 to 20 carbon atoms, including an epoxy group, amino group, unsaturated group, mercapto group, isocyanate group, acid anhydride group, or hydroxyl group. 2 R is an alkyl or aryl group having 1 to 10 carbon atoms. 3 (where X is a monovalent hydrocarbon group having 1 to 10 carbon atoms, X is 1 or 2, Y is 0 or 1, and X + Y is 1 or 2.) R 4 Z Si(OR 5 ) 4-Z (2) (In the formula, R 4 R is a monovalent hydrocarbon group having 1 to 20 carbon atoms. 5 (This refers to a monovalent hydrocarbon group with 1 to 10 carbon atoms. Z is an integer from 1 to 3.) The glass cloth described above is a silane-treated glass cloth having a plain weave structure in which glass yarn, made by bundling 30 to 250 glass filaments having an SiO2 composition of 45 to 100% by mass and an average filament diameter of 3 to 20 μm, is used as the warp and weft threads, and the weft and warp threads are woven at an independent density of 10 to 140 threads / inch, and the basis weight of the glass cloth is 8 to 250 g / m².

3. The silane-treated glass cloth according to Claim 1, wherein the total amount of components (i) and (ii) in the organoxysilane aqueous solution is 0.05 to 3% by mass relative to water.

4. The silane-treated glass cloth according to Claim 2, wherein the total amount of components (i), (iii), and (iv) in the organoxysilane aqueous solution is 0.05 to 3% by mass relative to water.

5. SiO2 in glass filaments 2 The silane-treated glass cloth according to claim 1 or 2, wherein the composition amount is 99 to 100% by mass.

6. A prepreg comprising a silane-treated glass cloth according to claim 1 or 2 and a matrix resin impregnated in the silane-treated glass cloth.

7. The prepreg according to claim 6, wherein the matrix resin is one or more resins selected from epoxy resin, silicone resin, polyimide resin, bismaleimide resin, polyphenylene ether resin, and polytetrafluoroethylene resin.

8. A printed circuit board comprising the prepreg according to claim 7.

Images