Surface-treated glass cloth, prepreg and printed wiring board

Abstract

Provided are: a surface-treated glass cloth capable of obtaining high insulation reliability in a printed wiring board and less likely to wrinkle during the production of a prepreg; a prepreg; and a printed wiring board. The surface-treated glass cloth has a surface-treated layer on the surface thereof, wherein the surface-treated layer has a first silane coupling agent having at least one methacryloyl group and a second silane coupling agent represented by general formula (1).　(1): X(R)3-nSiYn (In the formula, X is an alkyl group having 1-4 carbon atoms, Rs are each independently one group selected from the group consisting of a methyl group, an ethyl group, and a phenyl group, Ys are each independently an alkoxy group having 1-6 carbon atoms, and n is an integer of 1 to 3.)

Description

[Technical Field]

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

[0002] Conventionally, glass cloth used in printed wiring boards has been known to have a surface treatment layer on the surface containing a silane coupling agent having at least one methacryloyl group, such as 3-methacryloxypropyltrimethoxysilane (γ-methacryloxypropyltrimethoxysilane) (see, for example, Patent Document 1).

[0003] The surface-treated glass cloth described in Patent Document 1 has a small whitening distance, which indicates the degree of interfacial peeling between the glass and resin in the surface-treated layer when made into a printed wiring board, and can provide high insulation reliability in the printed wiring board. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6734422 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the surface-treated glass cloth described in Patent Document 1 has the disadvantage that it has a soft texture and is prone to wrinkling during the production of prepregs. Furthermore, in recent years, the trend toward smaller and thinner electronic devices has led to a demand for thinner glass cloths to be used in printed wiring boards, and since thin glass cloths are prone to wrinkling during production, handling of surface-treated glass cloths that are particularly soft in texture has become difficult.

[0006] In order to solve these problems, the present invention aims to provide a surface-treated glass cloth that can achieve high insulation reliability in printed wiring boards and is less likely to wrinkle during prepreg production, a prepreg using the surface-treated glass cloth, and a printed wiring board using the surface-treated glass cloth. [Means for solving the problem]

[0007] In order to achieve the above object, the surface-treated glass cloth of the present invention is a surface-treated glass cloth having a surface treatment layer on its surface, and the surface treatment layer contains a first silane coupling agent having at least one methacryloyl group and a second silane coupling agent represented by the following general formula (1): the total content of the first silane coupling agent and the second silane coupling agent is in the range of 0.03 to 1.50 mass % of the entire surface-treated glass cloth, and the ratio of the content of the second silane coupling agent to the content of the first silane coupling agent (content of the second silane coupling agent / content of the first silane coupling agent) is in the range of 0.01 to 0.25. It is characterized by:

[0008] X(R) 3-n SiY n ···(1) (In the formula, X is an alkyl group having 1 to 4 carbon atoms, each R is independently a group selected from the group consisting of a methyl group, an ethyl group, and a phenyl group, each Y is independently an alkoxy group having 1 to 6 carbon atoms, and n is an integer of 1 to 3.) The surface-treated glass cloth of the present invention has a surface treatment layer containing the first silane coupling agent and the second silane coupling agent on the surface thereof, thereby achieving high insulation reliability in printed wiring boards and, since the texture becomes hard, wrinkles are less likely to occur during the production of prepregs.

[0009] The second silane coupling agent has a fast hydrolysis rate and high silanol reactivity, which increases its adsorption to glass cloth and makes the glass cloth harder. Furthermore, the short alkyl chain of the second silane coupling agent results in a small molecular weight, which does not inhibit the reaction between the first silane coupling agent and resin, thereby achieving high insulation reliability in printed wiring boards.

[0010] In the surface-treated glass cloth of the present invention, the second silane coupling agent is represented by general formula (1), in which X is preferably a methyl group or an ethyl group, and more preferably a methyl group.

[0011] The surface-treated glass cloth of the present invention is ,before The ratio of the content of the second silane coupling agent to the content of the first silane coupling agent (content of the second silane coupling agent / content of the first silane coupling agent). is 0 Must be in the range of .03 to 0.17 I like I wish.

[0012] In the surface-treated glass cloth of the present invention, the total content of the first silane coupling agent and the second silane coupling agent is in the range of 0.03 to 1.50 mass % of the entire surface-treated glass cloth, and the ratio of the content of the second silane coupling agent to the content of the first silane coupling agent (content of second silane coupling agent / content of first silane coupling agent) is in the range of 0.01 to 0.25, thereby making it possible to obtain a good balance between high insulation reliability in printed wiring boards and the effect of hardening the texture of the glass cloth.

[0013] In the surface-treated glass cloth of the present invention, when the total content of the first silane coupling agent and the second silane coupling agent is less than 0.03% by mass of the entire surface-treated glass cloth, the amount of silane coupling agent attached is small, interfacial adhesion with resin is deteriorated, and high insulation reliability cannot be obtained. On the other hand, when the total content of the first silane coupling agent and the second silane coupling agent is more than 1.05% by mass of the entire surface-treated glass cloth, the concentration of the silane coupling agent in the aqueous glass-treating agent solution must be increased, which deteriorates the stability of the aqueous glass-treating agent solution, making it difficult to achieve stable continuous production over long periods of time.

[0014] Furthermore, when the ratio of the content of the second silane coupling agent to the content of the first silane coupling agent (content of the second silane coupling agent / content of the first silane coupling agent) of the surface-treated glass cloth of the present invention is less than 0.01, the effect of hardening the texture cannot be obtained, and when it exceeds 0.25, dehydration condensation of the second silane coupling agent is likely to occur, making it difficult to stably produce the glass cloth for a long period of time.

[0015] In the surface-treated glass cloth of the present invention, the surface treatment layer preferably does not contain a surfactant. Since the surface treatment layer of the surface-treated glass cloth of the present invention does not contain a surfactant, impregnation is improved and high insulation reliability can be obtained in printed wiring boards.

[0016] The surface-treated glass cloth of the present invention preferably has a thickness in the range of 5 to 25 μm. Although the effects of the present invention can be obtained even when the surface-treated glass cloth of the present invention has a thickness of more than 25 μm, a thickness in the range of 5 to 25 μm makes it possible to obtain a good balance between high insulation reliability in printed wiring boards and the effect of hardening the texture of the glass cloth. Furthermore, it is technically difficult to produce the surface-treated glass cloth of the present invention so that the thickness is less than 5 μm.

[0017] The prepreg of the present invention is characterized by containing the surface-treated glass cloth of the present invention, and the printed wiring board of the present invention is characterized by containing the surface-treated glass cloth of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] Next, the embodiment of the present invention will be described in more detail.

[0019] The surface-treated glass cloth of this embodiment has a surface treatment layer on its surface, and the surface treatment layer contains a first silane coupling agent having at least one methacryloyl group and a second silane coupling agent represented by the following general formula (1):

[0020] X(R) 3-n SiY n ···(1) (In the formula, X is an alkyl group having 1 to 4 carbon atoms, each R is independently a group selected from the group consisting of a methyl group, an ethyl group, and a phenyl group, each Y is independently an alkoxy group having 1 to 6 carbon atoms, and n is an integer of 1 to 3.) In the surface-treated glass cloth of this embodiment, the second silane coupling agent is represented by general formula (1), in which X is preferably a methyl group or an ethyl group, and more preferably a methyl group.

[0021] The surface-treated glass cloth of this embodiment can be produced, for example, as follows.

[0022] First, a predetermined glass batch (glass raw material) is melted and fiberized to obtain glass filaments. The glass composition constituting the glass filaments is not particularly limited, but compositions such as E glass, T glass, NE glass, and L glass are preferred. From the viewpoint of low dielectric constant and low dielectric loss tangent, NE glass and L glass are more preferable, and specifically, a composition containing, relative to the total amount, SiO2 in the range of 48.0 to 62.0 mass%, B2O3 in the range of 17.0 to 26.0 mass%, Al2O3 in the range of 9.0 to 18.0 mass%, MgO in the range of 0 to 6.0 mass%, CaO in the range of 0.1 to 9.0 mass%, Na2O, K2O, and Li2O in a total range of 0 to 0.5 mass%, TiO2 in the range of 0 to 5.0 mass%, SrO in the range of 0 to 6.0 mass%, P2O5 in the range of 0 to 6.0 mass%, and F2 and Cl2 in a total range of 0 to 3.0 mass% is more preferable.

[0023] Here, the content of each component in the composition of the above-mentioned glass can be measured using an ICP optical emission spectrometer for the light element Li, and a wavelength dispersive X-ray fluorescence analyzer for the other elements.

[0024] The measurement method involves cutting glass cloth (if organic matter adheres to the glass cloth surface or if the glass cloth is primarily contained in organic matter (resin) as a reinforcing material, the organic matter is removed by, for example, heating in a muffle furnace at 300 to 600°C for 2 to 24 hours) into an appropriate size, placing it in a platinum crucible, and melting it in an electric furnace at 1550°C for 6 hours while stirring, to obtain homogeneous molten glass. The resulting molten glass is then poured onto a carbon plate to produce glass cullet, which is then crushed and powdered. For the light element Li, the glass powder is thermally decomposed with acid and quantitatively analyzed using an ICP atomic emission spectrometer. For other elements, the glass powder is molded into a disk shape using a press and quantitatively analyzed using a wavelength-dispersive X-ray fluorescence spectrometer. The results of these quantitative analyses are converted into oxides to calculate the content and total amount of each component, and from these values, the content (mass%) of each of the aforementioned components can be determined.

[0025] The diameter of the glass filaments is not particularly limited, but for printed wiring board applications it is preferably 10 μm or less, more preferably 8 μm or less, and particularly preferably in the range of 3 to 5 μm.

[0026] The glass filaments are bundled by a method known per se to form a glass fiber yarn, for example, in a number ranging from 25 to 500, preferably from 40 to 300. Note that the process of melting a glass batch, fiberizing it to obtain glass filaments, and then bundling a plurality of these glass filaments to obtain a glass fiber yarn is called spinning.

[0027] The filament diameter of the glass filaments is the average value of the measured values ​​obtained by measuring the diameter of the glass filaments constituting the warp or weft at 50 points on the cross section of each of the warp and weft yarns of the glass cloth using a scanning electron microscope (manufactured by Hitachi High-Technologies Corporation, product name: S-3400N, magnification: 3000x). The number of glass filaments is the average value of the measured values ​​obtained by measuring the number of glass filaments constituting the warp or weft at 50 points on the cross section of each of the warp and weft yarns of the glass cloth using a scanning electron microscope (manufactured by Hitachi High-Technologies Corporation, product name: S-3400N, magnification: 500x).

[0028] The count of the glass fiber yarn is preferably 0.8 to 135 tex, and more preferably 1 to 25 tex. The count (tex) of the glass fiber yarn corresponds to the mass (unit: g) of the glass fiber per 1000 m.

[0029] Next, the glass fiber yarns are woven as warp or weft to obtain a glass cloth. The weaving method is not particularly limited, but examples thereof include plain weave, satin weave, and twill weave, with plain weave being preferred. The weaving density of the glass fiber yarns during weaving is not particularly limited, but is preferably in the range of 10 to 150 yarns / 25 mm, and more preferably in the range of 40 to 100 yarns / 25 mm.

[0030] The weave density of the glass fiber yarns can be determined in accordance with JIS R 3420 by using a fabric disassembly speculum to count the number of warp or weft yarns within a 25 mm range in the warp or weft direction.

[0031] During the weaving process, a sizing agent is used for bundling the glass filaments and arranging the warp threads. Examples of the sizing agent include a starch-based or PVA (polyvinyl alcohol)-based film-forming agent. The sizing agent may contain an oil or a softener.

[0032] The amount of the sizing agent attached to the glass cloth is preferably 0.1 to 3 parts by mass, and more preferably 0.5 to 1.5 parts by mass, per 100 parts by mass of the glass fiber yarns. Note that the range of the amount of the sizing agent attached and the amount of the sizing agent attached when not otherwise specified represent the average amount of the sizing agent attached to the warp or weft yarns.

[0033] The glass cloth obtained by the weaving process has a mass per unit area of ​​110 g / m from the viewpoint of use as a substrate for printed wiring boards. 2 On the other hand, from the viewpoint of weaving, it is preferable that the mass per unit area of ​​the glass cloth is 8 g / m or less. 2 It is preferable that this is equal to or greater than this.

[0034] The mass of the glass cloth was measured by cutting the glass cloth into a size of 200 mm x 200 mm using a scale conforming to JIS R 3420 and measuring the mass at three points. 2 The average value converted into mass per unit.

[0035] Next, the glass cloth is subjected to an opening treatment. Examples of the opening treatment include opening by water flow pressure, opening by high-frequency vibration using a liquid as a medium, opening by pressure of a fluid having a surface pressure, and opening by pressure using a roll. Among the opening treatments, opening by water flow pressure or opening by high-frequency vibration using a liquid as a medium is preferred because it reduces variations in yarn width after opening treatment for both the warp and weft yarns. Furthermore, a plurality of treatment methods may be used in combination for the opening treatment.

[0036] Next, the glass cloth that has been subjected to the fiber-opening treatment is subjected to a deoiling treatment, which can be carried out, for example, by placing the glass cloth in a heating furnace at an atmospheric temperature of 350°C to 450°C for a period of 40 to 80 hours, and thermally decomposing the spinning sizing agent and weaving sizing agent that are attached to the glass cloth.

[0037] Next, the deoiled glass cloth is immersed in an aqueous solution of a surface treatment agent, excess water is squeezed out, and then the glass cloth is dried by heating at a temperature in the range of 80 to 180°C for a time in the range of 1 to 30 minutes, for example, at 110°C for 5 minutes, to obtain the surface-treated glass cloth of this embodiment.

[0038] The aqueous surface treatment agent solution may contain a first silane coupling agent having at least one methacryloyl group and a second silane coupling agent represented by the following general formula (1) in a range of 0.1 to 2.0 mass % as solid content relative to the total amount of the aqueous surface treatment agent solution, and may contain a weak acid (e.g., acetic acid, citric acid, propionic acid, etc.) as a pH adjuster in a range of 0.5 to 2.0 mass %.

[0039] X(R) 3-n SiY n ···(1) (In the formula, X is an alkyl group having 1 to 4 carbon atoms, each R is independently a group selected from the group consisting of a methyl group, an ethyl group, and a phenyl group, each Y is independently an alkoxy group having 1 to 6 carbon atoms, and n is an integer of 1 to 3.) Examples of the silane coupling agent having at least one methacryloyl group include 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropyltriethoxysilane.

[0040] Examples of the second silane coupling agent represented by the general formula (1) include methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, and butyltrimethoxysilane. The second silane coupling agent is preferably one in which X in the general formula (1) is a methyl group or an ethyl group, and examples of such a second silane coupling agent include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, and ethyltriethoxysilane. More preferably, the second silane coupling agent is one in which X in the general formula (1) is a methyl group, and examples of such a second silane coupling agent include methyltrimethoxysilane and methyltriethoxysilane, with methyltrimethoxysilane being the most preferred.

[0041] In the surface-treated glass cloth of this embodiment, the total content of the first silane coupling agent and the second silane coupling agent is preferably in the range of 0.03 to 1.50 mass%, more preferably in the range of 0.05 to 1.20 mass%, even more preferably in the range of 0.1 to 1.0 mass%, particularly preferably in the range of 0.2 to 0.8 mass%, particularly preferably in the range of 0.3 to 0.7 mass%, and most preferably in the range of 0.4 to 0.6 mass%, based on the total amount of the surface-treated glass cloth.

[0042] Furthermore, in the surface-treated glass cloth of this embodiment, the ratio of the content of the second silane coupling agent to the content of the first silane coupling agent (content of the second silane coupling agent / content of the first silane coupling agent) is preferably in the range of 0.01 to 0.25, more preferably in the range of 0.03 to 0.20, even more preferably in the range of 0.03 to 0.17, and most preferably in the range of 0.10 to 0.17.

[0043] As a result, a surface-treated glass cloth of this embodiment can be obtained, which has a surface treatment layer on its surface, the surface of which contains a first silane coupling agent having at least one methacryloyl group and a second silane coupling agent represented by the general formula (1).

[0044] Furthermore, in the surface-treated glass cloth of this embodiment, the surface treatment layer preferably does not contain a surfactant, and the thickness is preferably in the range of 5 to 60 μm, more preferably in the range of 5 to 40 μm, and even more preferably in the range of 5 to 25 μm.

[0045] Here, the thickness of the surface-treated glass cloth can be determined by measuring the thickness of the surface-treated glass cloth at 15 points with a micrometer in accordance with JIS R 3420, and the average value of the measured values ​​can be used.

[0046] Next, examples of the present invention, comparative examples, and reference examples will be described. [Example]

[0047] Example 1 In this example, the cross style #1017 of the IPC4412 standard (glass composition: NE glass, yarn used: BC3000 (filament diameter 4.0 μm, yarn weight 1.5 tex), warp weave density: 95 / 25 mm, weft weave density: 95 / 25 mm, mass per unit area: 11.4 g / m) 2 ) was woven, and the glass cloth was opened by spraying a high-pressure water stream of 40°C having a pressure of 2 MPa onto the glass cloth, and then heated at a temperature of 400 to 450°C for 60 hours to perform a deoiling treatment.The deoiling-treated glass cloth was then immersed in an aqueous solution of a glass treatment agent, and excess water was squeezed out, followed by heating and drying at 110°C for 5 minutes to obtain a surface-treated glass cloth of this example.

[0048] The glass treatment agent aqueous solution was prepared by mixing 1.0 mass% of 3-methacryloxypropyltrimethoxysilane (manufactured by Dow Toray Industries, Inc.) as the first silane coupling agent, 0.15 mass% of methyltrimethoxysilane (manufactured by Momentive Performance Materials Japan, LLC) as the second silane coupling agent, and 0.5 mass% of acetic acid with water, and stirring the mixture with a magnetic stirrer for 1 hour.

[0049] The resulting surface-treated glass cloth was cut into 350 mm × 400 mm pieces, and the resulting surface-treated glass cloth pieces were immersed in polyphenylene ether resin varnish and pre-dried at 150 °C for 10 minutes to obtain a prepreg. The polyphenylene ether resin varnish consisted of 450 parts by mass of oligophenylene ether (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 α,α'-di(tert-butylperoxy)diisopropylbenzene (manufactured by NOF Corporation, trade name: Perbutyl P), and 250 parts by mass of toluene (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.).

[0050] Next, four sheets of the prepreg were stacked together, with cellophane films on top and bottom, and heated and pressed for a predetermined time using a vacuum hot press (Kitagawa Seiki Co., Ltd.) to obtain a laminated plate with a thickness of approximately 0.2 mm.

[0051] Next, the laminate obtained in this example was cut into a 7 cm x 4 cm piece and 2 cm long slits were made vertically and horizontally using a diamond cutter 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 specimens were then immersed in the solution for 24 hours. The whitening distance due to interfacial peeling between the resin and glass in the warp and weft directions was measured at 100x magnification using a digital microscope (manufactured by Keyence Corporation). Measurements were taken at 24 points in each of the warp and weft directions, and the average value was calculated to determine the whitening distance. This 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.

[0052] Next, the surface-treated glass cloth obtained in this example was cut to 90 mm x 30 mm to prepare glass cloth pieces for texture measurement. The measurement was performed in accordance with the bending resistance test using the sliding method of JIS L 1096. One end of the short side of the glass cloth piece for texture measurement was fixed to a horizontal table 30 mm in the long side direction, and the remaining part was placed as a free end on a moving table whose top surface was flush with the horizontal table. Using the top surface of the horizontal table as a reference, the moving table was lowered and the distance traveled until the center of the tip of the free end separated from the moving table was measured. Measurements were performed using five glass cloth pieces for texture measurement, and the average value was calculated. The moving distance of the moving table correlates with the texture of the glass cloth; the shorter the moving distance, the harder the texture of the glass cloth.

[0053] Next, the surface-treated glass cloth obtained in this example was cut to 60 mm x 40 mm to prepare a 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 penetrated the glass cloth piece for evaluating impregnation was measured in the weft direction. Measurements were carried out using five glass cloth pieces for evaluating impregnation, and the average value was calculated. The measurement results for whitening distance, texture, and impregnation are shown in Table 1. In Table 1, 3-methacryloxypropyltrimethoxysilane is abbreviated as "methacryl" and methyltrimethoxysilane is abbreviated as "methylsilane."

[0054] Example 2 In this example, the surface-treated glass cloth, prepreg, and laminate were obtained in exactly the same manner as in Example 1, except that the amount of methyltrimethoxysilane (manufactured by Momentive Performance Materials Japan, LLC) as the second silane coupling agent contained in the glass treatment agent aqueous solution was set to 0.05 mass%.

[0055] Next, except that the surface-treated glass cloth and laminate obtained in this example were used, the whitening distance, texture, and impregnation were measured in exactly the same manner as in Example 1. The measurement results are shown in Table 1.

[0056] Example 3 In this example, surface-treated glass cloth, prepreg, and laminate were obtained in exactly the same manner as in Example 2, except that 0.001 mass % of polyoxyethylene alkyl ether (manufactured by Toho Chemical Industry Co., Ltd.) was added as a surfactant to the aqueous glass treatment agent solution.

[0057] Next, except that the surface-treated glass cloth and laminate obtained in this example were used, the whitening distance, texture, and impregnation were measured in exactly the same manner as in Example 1. The measurement results are shown in Table 1.

[0058] Example 4 In this example, the surface-treated glass cloth, prepreg, and laminate were obtained in exactly the same manner as in Example 1, except that the amount of methyltrimethoxysilane (manufactured by Momentive Performance Materials Japan, LLC) as the second silane coupling agent contained in the glass treatment agent aqueous solution was set to 0.19 mass%.

[0059] Next, except that the surface-treated glass cloth and laminate obtained in this example were used, the whitening distance, texture, and impregnation were measured in exactly the same manner as in Example 1. The measurement results are shown in Table 1.

[0060] Example 5 In this example, a surface-treated glass cloth, a prepreg, and a laminate were obtained in exactly the same manner as in Example 1, except that 0.05 mass% of propyltrimethoxysilane (manufactured by Shin-Etsu Silicones Co., Ltd.) was used instead of methyltrimethoxysilane (manufactured by Momentive Performance Materials Japan, LLC) as the second silane coupling agent contained in the aqueous glass treatment agent solution.

[0061] Next, except that the surface-treated glass cloth and laminate obtained in this example were used, the whitening distance, texture, and impregnation were measured in exactly the same manner as in Example 1. The measurement results are shown in Table 1.

[0062] In Table 1, propyltrimethoxysilane is abbreviated as "propylsilane."

[0063] Example 6 In this example, the cross style #1078 of the IPC4412 standard (glass composition: NE glass, yarn used: D450 (filament diameter 5.0 μm, yarn weight 10.0 tex), warp weave density: 53 / 25 mm, weft weave density: 53 / 25 mm, mass per unit area: 44.0 g / m) 2 The surface-treated glass cloth, prepreg, and laminate were obtained in exactly the same manner as in Example 1, except that the glass cloth of Example 1 was used.

[0064] Next, except that the surface-treated glass cloth and laminate obtained in this example were used, the whitening distance, texture, and impregnation were measured in exactly the same manner as in Example 1. The measurement results are shown in Table 2.

[0065] Comparative Example 1 In this comparative example, a surface-treated glass cloth, a prepreg, and a laminate were obtained in exactly the same manner as in Example 1, except that 0.05 mass% of hexyltrimethoxysilane (manufactured by Dow Toray Industries, Inc.) was used instead of methyltrimethoxysilane (manufactured by Momentive Performance Materials Japan, LLC) as the second silane coupling agent contained in the aqueous glass treatment agent solution.

[0066] Next, except that the surface-treated glass cloth and laminate obtained in this comparative example were used, the whitening distance, texture, and impregnation were measured in exactly the same manner as in Example 1. The measurement results are shown in Table 2.

[0067] In Table 2, hexyltrimethoxysilane is abbreviated as "hexylsilane."

[0068] [Reference example 1] In this reference example, the surface-treated glass cloth, prepreg, and laminate were obtained in exactly the same manner as in Example 1, except that the silane coupling agent contained in the glass treatment agent aqueous solution was 1.0 mass% of 3-methacryloxypropyltrimethoxysilane (manufactured by Dow-Toray Industries, Inc.) as the first silane coupling agent, and no second silane coupling agent was contained.

[0069] Next, except that the surface-treated glass cloth and laminate obtained in this Reference Example were used, the whitening distance, texture, and impregnation were measured in exactly the same manner as in Example 1. The measurement results are shown in Table 2.

[0070] [Reference example 2] In this reference example, the surface-treated glass cloth, prepreg, and laminate were obtained in exactly the same manner as in Example 6, except that the silane coupling agent contained in the glass treatment agent aqueous solution was 1.0 mass% of 3-methacryloxypropyltrimethoxysilane (manufactured by Dow-Toray Industries, Inc.) as the first silane coupling agent, and no second silane coupling agent was contained.

[0071] Next, except that the surface-treated glass cloth and laminate obtained in this Reference Example were used, the whitening distance, texture, and impregnation were measured in exactly the same manner as in Example 1. The measurement results are shown in Table 2.

[0072] [Table 1]

[0073] [Table 2]

[0074] In Tables 1 and 2, "whitening distance deterioration rate" indicates the rate of increase in whitening distance relative to the whitening distance of Reference Example 1 for Examples 1 to 5 and Comparative Example 1, and indicates the rate of increase in whitening distance relative to the whitening distance of Reference Example 2 for Example 6. In Tables 1 and 2, "feel improvement rate" indicates the rate of decrease in texture relative to the texture of Reference Example 1 for Examples 1 to 5 and Comparative Example 1, and indicates the rate of decrease in texture relative to the texture of Reference Example 2 for Example 6.

[0075] Furthermore, the "feel improvement rate / whitening distance deterioration rate" in Tables 1 and 2 is an index showing the high insulation reliability of the printed wiring board and the resistance to wrinkling during prepreg manufacturing; the larger the value, the higher the insulation reliability of the printed wiring board and the less likely it is to wrinkle during prepreg manufacturing.

[0076] As is clear from Tables 1 and 2, the surface-treated glass cloths of Examples 1 to 6, which have a surface treatment layer on their surface containing a first silane coupling agent having at least one methacryloyl group and a second silane coupling agent represented by general formula (1), have a larger numerical value for texture improvement rate / whitening distance deterioration rate than the surface-treated glass cloth of Comparative Example 1, which has a surface treatment layer on its surface containing a first silane coupling agent having at least one methacryloyl group but not containing the second silane coupling agent represented by general formula (1), and it is clear that high insulation reliability can be obtained in printed wiring boards and wrinkles are less likely to occur during the production of prepregs.

Claims

1. A surface-treated glass cloth having a surface treatment layer on its surface, The surface-treated glass cloth is characterized in that the surface-treated layer contains a first silane coupling agent having at least one methacryloyl group and a second silane coupling agent represented by the following general formula (1), the total content of the first silane coupling agent and the second silane coupling agent is in the range of 0.03 to 1.50 mass% of the entire surface-treated glass cloth, and the ratio of the content of the second silane coupling agent to the content of the first silane coupling agent (content of second silane coupling agent / content of first silane coupling agent) is in the range of 0.01 to 0.

25. X (R) ３－ｎ Yes ｎ ・・・(1) (In the formula, X is an alkyl group having 1 to 4 carbon atoms, each R is independently a group selected from the group consisting of a methyl group, an ethyl group, and a phenyl group, each Y is independently an alkoxy group having 1 to 6 carbon atoms, and n is an integer of 1 to 3.)

2. 2. The surface-treated glass cloth according to claim 1, wherein the second silane coupling agent is represented by the general formula (1), in which X is a methyl group or an ethyl group.

3. 3. The surface-treated glass cloth according to claim 1, wherein the second silane coupling agent is a compound represented by general formula (1), in which X is a methyl group.

4. A surface-treated glass cloth according to any one of claims 1 to 3, characterized in that the ratio of the content of the second silane coupling agent to the content of the first silane coupling agent (content of the second silane coupling agent / content of the first silane coupling agent) is in the range of 0.03 to 0.

17.

5. 5. The surface-treated glass cloth according to claim 1, wherein the surface-treated layer does not contain a surfactant.

6. The surface-treated glass cloth according to any one of claims 1 to 5, characterized in that the thickness is in the range of 5 to 25 µm.

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.

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