JP2007091964A - Curable silicone resin sheet composited with glass cloth - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical sheet having excellent optical properties and small variation of expansion coefficient and elastic modulus with temperature change, suitable for forming an inorganic layer and usable as a substitute for a glass substrate. <P>SOLUTION: The transparent resin sheet (c) composited with a glass cloth is produced by compositing (a) a curable silicone resin composed of (a-1) a silicone resin and (a-2) a curable resin with (b) a glass cloth, wherein the storage elastic modulus of the curable silicone resin (a) determined by dynamic viscoelasticity measurement satisfies the formula E<SB>0</SB>'<SB>35</SB>/E<SB>0</SB>'<SB>290</SB>≤8 and the refractive index difference between the curable silicone resin (a) and the glass cloth (b) is ≤0.02. In the formula, E<SB>0</SB>'<SB>35</SB>is the storage elastic modulus of the curable silicone resin measured at 35°C by dynamic viscoelasticity measurement and E<SB>0</SB>'<SB>290</SB>is the storage elastic modulus of the curable silicone resin measured at 290°C by dynamic viscoelasticity measurement. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical sheet having a small linear expansion coefficient, excellent optical characteristics, and capable of replacing a glass substrate, and also relates to a display element substrate using the same. The optical sheet of the present invention is suitable for a liquid crystal display element substrate, an organic EL display element substrate, a color filter substrate, a touch panel substrate, a solar cell substrate, and the like.

  In general, glass substrates are generally used for display element substrates for liquid crystal display elements and organic EL display elements, color filter substrates, touch panel substrates, and solar cell substrates. However, in recent years, plastic substrates have been studied as an alternative to glass substrates because they are easily broken, cannot be bent, have a large specific gravity, and are not suitable for weight reduction. For example, Patent Document 1 and Patent Document 2 describe a transparent resin substrate for a liquid crystal display element comprising a cured product obtained by curing an epoxy resin composition containing an epoxy resin, an acid anhydride curing agent, and a curing catalyst. Yes. However, these resin single materials have a larger coefficient of linear expansion than glass plates, causing problems such as warpage and disconnection of aluminum wiring in the manufacturing process of the display element substrate, and are difficult to use in these applications. Accordingly, there is a demand for a plastic material having a small linear expansion coefficient while satisfying the transparency, heat resistance, etc. required for a display element substrate, particularly an active matrix display element substrate.

  In order to reduce the coefficient of linear expansion, it is often performed to combine an inorganic filler such as glass fiber with a resin. However, a composite material that is normally transparent cannot be obtained by combining these resin and inorganic filler. . This is mainly because light transmitted through the resin is scattered at the interface between the resin and the inorganic filler because the refractive index of the resin is different from that of the inorganic filler. In order to solve such problems, various studies have been made to make the resin transparent by matching the refractive index of the resin with that of the inorganic filler. For example, Patent Document 3 and Patent Document 4 show that a transparent composite material can be obtained by reducing the difference in refractive index between a cyclic olefin resin and glass fiber. However, the cyclic olefin resin used here is a thermoplastic resin, and it is inevitable that the elastic modulus is lowered above the glass transition temperature.

Furthermore, using a glass cloth as an inorganic filler, a resin and a glass cloth are combined, and the refractive index of the resin and the glass cloth is matched to obtain a transparent composite composition.
For example, in Patent Document 5 and Patent Document 6, a composite material having a low linear expansion coefficient and high transparency is obtained by using a curable resin such as an epoxy resin or an acrylate resin for a glass cloth and matching the refractive index with the Abbe number. It has been shown to be obtained. However, these resins and resins used for inorganic filler transparent composite materials are epoxy resins and acrylate resins, which are general-purpose curable resins, and also have a glass transition temperature, so that the elastic modulus is higher than the glass transition temperature. descend. Therefore, there is expansion and deformation of the sheet due to heating, and it is difficult to stably form a uniform laminated structure when the inorganic layers are laminated.
Therefore, there has been a demand for a transparent composite sheet in which the change in elastic modulus is small before and after the glass transition temperature, and the degree of expansion and deformation of the sheet due to heating is small.

JP-A-6-337408 JP-A-7-120740 JP-A-6-256604 JP-A-6-305077 JP-A-2004-231934 JP 2004-51960 A

  An object of the present invention is to provide a transparent resin sheet having high transparency, a low coefficient of linear expansion, a small change in elastic modulus with a change in temperature, and a high heat resistance.

In order to solve the above-mentioned problems, the present inventor uses a silicone-based curable resin having a low linear expansion coefficient by combining a resin and a glass cloth and having a refractive index that matches that of the glass cloth as a resin. The present inventors have found that a transparent resin sheet having high properties can be obtained, and have made the present invention.
That is, this invention is a glass cloth composite transparent resin sheet as described below.

(1) A glass cloth composite comprising a silicone curable resin (a) having a silicone resin (a-1) and a curable resin (a-2) as constituent elements and a glass cloth (b). In the transparent resin sheet (c), the relationship of the storage elastic modulus of the silicone curable resin (a) in the dynamic viscoelasticity measurement satisfies the following formula, and the silicone curable resin (a) and the glass cloth (b) The glass cloth composite transparent resin sheet characterized by the difference in refractive index of 0.02 or less.
E _{0 '35} / E ₀ ' ₂₉₀ ≦ 8
However,
E _{0 '35:} the storage modulus of the silicone-based curable resin at 35 ° C. in a dynamic viscoelasticity measurement E _{0' 290:} the storage modulus of the silicone-based curable resin at 290 ° C. in the dynamic viscoelasticity measurement (2 ) A glass cloth composite transparent resin obtained by compounding a silicone curable resin (a) having a silicone resin (a-1) and a curable resin (a-2) as constituent elements and a glass cloth (b). In the sheet (c), the relationship of the storage elastic modulus of the glass cloth composite transparent silicone curable resin sheet (c) in the dynamic viscoelasticity measurement satisfies the following formula, and the silicone curable resin (a) and the glass A glass cloth composite transparent resin sheet, wherein the difference in refractive index of the cloth (b) is 0.02 or less.
E _{1 '35} / E ₁ ' ₂₉₀ ≦ 1.5
However,
E _{1 '35:} dynamic viscoelasticity storage modulus E ₁ of the glass cloth composite transparent resin sheet at 35 ° C. in the measurement' _290: storage of the glass cloth composite transparent resin sheet at 290 ° C. in a dynamic viscoelasticity measurement (1) or (2) above, wherein the elastic modulus (3) the silicone resin (a-1) is a silicone resin having an epoxy group and the curable resin (a-2) is an epoxy resin The glass cloth composite transparent resin sheet as described in 1.
(4) The silicone resin (a-1) is a silicone resin having an epoxy group, the curable resin (a-2) is an epoxy resin, and a polyfunctional amine curing agent is used as a curing agent in the production of the sheet. The glass cloth composite transparent resin sheet according to any one of (1) to (3) above, wherein
It is.

  The glass cloth composite transparent resin sheet of the present invention has the effects of high transparency, a small coefficient of linear expansion, a small change in elastic modulus due to a temperature change, and a high heat resistance. As a result, since expansion and deformation of the sheet due to heating are small, it can be expected that a stable and uniform laminated structure is formed when the inorganic layer is laminated.

The present invention will be specifically described below.
The glass cloth composite transparent resin sheet of the present invention comprises a silicone-based curable resin (a) obtained by using a silicone resin (a-1) and a curable resin (a-2) as raw materials, and a glass cloth (b). It can be manufactured by compounding.
The silicone-based curable resin (a) used in the present invention is obtained by mixing the silicone resin (a-1) and the curable resin (a-2), and then curing by heating or irradiating light. Can do. Moreover, a glass cloth composite transparent resin sheet can be obtained by impregnating the glass cloth before completely curing the silicone resin and the curable resin.

  The mixing ratio of the silicone resin (a-1) and the curable resin (a-2) constituting the silicone-based curable resin (a) used in the present invention is 5 to 90% by weight: 95 to 10% by weight. Yes, preferably 5 to 80% by weight: 95 to 20% by weight. When the silicone resin (a-1) is less than 5% by weight, the effect of forming a molecular bond with the epoxy resin is small, and when it is larger than 90% by weight, the flexibility is poor.

The silicone-based curable resin (a) used in the present invention is characterized in that the difference in elastic modulus between room temperature and high temperature is small. That is, the relationship of the storage elastic modulus in the dynamic viscoelasticity measurement satisfies the following formula.
E _{0 '35} / E ₀ ' ₂₉₀ ≦ 8
E _{0 '35:} the storage modulus of the silicone-based curable resin at 35 ° C. in a dynamic viscoelasticity measurement E _{0' 290:} more preferably the storage modulus of the silicone-based curable resin at 290 ° C. in a dynamic viscoelasticity measurement Is E _{0 '35} / E ₀ ' ₂₉₀ ≦ 5 It is.
In the case of E _{0 '35} / E ₀ ' ₂₉₀ ≦ 8, a glass cloth composite transparent resin sheet (c) formed by combining this silicone-based curable resin (a) with glass cloth (b) is a sheet by heating. Since the degree of expansion and deformation of the substrate is small, the surface treatment process of imparting conductivity and imparting gas barrier properties, which is necessary for glass substitute applications for display element substrates, becomes easy.

When the storage elastic modulus of the silicone-based curable resin (a) having the silicone resin (a-1) and the curable resin (a-2) as constituent elements is in the above range, the silicone-based curable resin (a) The glass cloth composite transparent resin sheet (c) obtained by combining the glass cloth (b) and the storage modulus of the glass cloth composite transparent resin sheet (c) in the dynamic viscoelasticity measurement is expressed by the following equation: It tends to satisfy.
E _{1 '35} / E ₁ ' ₂₉₀ ≦ 1.5
E _{1 '35:} dynamic viscoelasticity storage modulus E ₁ of the glass cloth composite transparent resin sheet at 35 ° C. in the measurement' _290: storage of the glass cloth composite transparent resin sheet at 290 ° C. in a dynamic viscoelasticity measurement Elastic modulus The fact that the dynamic viscoelasticity of the glass cloth composite transparent resin sheet is the above relational expression indicates that the decrease in the strength of the sheet due to temperature change is small. As a result, the degree of expansion and deformation of the sheet due to heating is reduced.

  The glass cloth composite transparent resin sheet of the present invention is transparent. By being transparent, it can be used for a liquid crystal display element substrate, an organic EL display element substrate, a color filter substrate, a touch panel substrate, and a solar cell substrate. The term “transparent” in the present invention means that the light transmittance in the wavelength region of visible light is 60% or more, preferably 80% or more. The wavelength region of visible light in the present invention is 400 nm to 800 nm.

The silicone resin (a-1) in the present invention is a resin that necessarily contains silicon, oxygen, carbon, and hydrogen. Furthermore, it is possible to include metals such as titanium, zirconium, germanium, aluminum, and indium.
The silicone resin (a-1) in the present invention can be synthesized, for example, by a sol-gel reaction in which alkoxysilane or chlorosilane is a main component and water is removed and alcohol is removed and dehydrated in the presence of a catalyst.
The alkoxysilane and chlorosilane used when synthesizing the silicone resin (a-1) in the present invention are monomers of an organic silane having an alkyl group or an allyl group. Examples of the alkyl group include a methyl group, an ethyl group, an isopropyl group, a glycidyloxypropyl group, an epoxycyclohexenylethyl group, an acrylate group, and a methacrylate group.

  In order to achieve the small difference in elastic modulus between room temperature and high temperature, which is a characteristic of the silicone-based curable resin (a) in the present invention, the curable resin is cured in the silicone resin (a-1). It preferably has a functional group that forms a chemical bond with the curable resin. For example, in the case of an epoxy resin, it preferably has a glycidyloxypropyl group, an epoxycyclohexenylethyl group, or an amino group, and when the curable resin is a (meth) acrylate resin, an acrylate group, a methacrylate group, or a vinyl group It is preferable to have.

  As catalysts for the sol-gel reaction, acids such as hydrochloric acid, nitric acid, formic acid and acetic acid, bases such as sodium hydroxide, potassium hydroxide, cesium hydroxide and triethylamine, and metal catalysts such as dibutyltin laurate are used alone or in combination. be able to.

The curable resin (a-2) in the present invention means a relatively low molecular weight substance that is liquid, semi-solid or solid at room temperature and exhibits fluidity at room temperature or under heating. These can be insoluble and infusible resins formed by forming a network-like three-dimensional structure while increasing the molecular weight by causing a curing reaction or a crosslinking reaction by the action of a curing agent, a catalyst, heat or light.
As curable resin (a-2) in this invention, if the hardened | cured material is transparent and the hardened | cured material synthesize | combined while mixing with a silicone resin is transparent, all can be used. For example, transparent epoxy resin, (meth) acrylate resin, thermosetting polyimide resin, urea resin, melamine resin, unsaturated polyester resin, and the like can be given. Among these, an epoxy resin and a (meth) acrylate resin are preferable, and an epoxy resin is more preferable.

  The epoxy resin refers to an organic compound having at least two epoxy groups. Specific examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, brominated bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, biphenyl type epoxy resin, bisphenol S type epoxy resin, and bisphenol S type. Epoxy resin, phenol novolac type epoxy resin, orthocresol novolak type epoxy resin, bisphenol A novolac type epoxy resin, naphthalene type epoxy resin, trishydroxymethane type epoxy resin, tetraphenolethane type epoxy resin, fluorene-containing epoxy resin, hexahydro anhydride phthalate Acid type epoxy resin, tetrahydrophthalic anhydride type epoxy resin, dimer acid type epoxy resin, tetraglycidyl diamino phenylmethane, triglycy Ruisocyanurate, aminophenol type epoxy resin, aniline type epoxy resin, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, alicyclic acetal type epoxy resin, alicyclic adipate type epoxy resin, Examples thereof include alicyclic carboxylate type epoxy resins and vinylcyclohexene type epoxy resins. The molecular weight or epoxy equivalent of the epoxy resin can be arbitrarily selected. These epoxy resins can be used alone or in admixture of two or more.

  The epoxy resin used in the present invention is generally used after being cured by heating or light irradiation in the presence of a curing agent or a polymerization initiator. The curing agent and the curing catalyst used are not particularly limited as long as they are used for curing the epoxy resin. Examples of the curing agent include polyfunctional amines, polyamides, acid anhydrides, and phenol resins, and examples of the curing catalyst include imidazole and onium salts. Of these, polyfunctional amine curing agents are preferred. As a polyfunctional amine curing agent, a compound having two or more primary amino groups in one molecule is shown. Specific examples of curing agents include triethylenetetramine, diethylaminopropylamine, diaminodiphenylmethane, diaminocyclohexylmethane, metaxylenediamine, dicyandiamide, adipic acid dihydrazide, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyl nadic anhydride, anhydrous Phthalic acid, pyromellitic anhydride, trimellitic anhydride, phenol novolac, polysulfide, trioxane trimethylene mercaptan, 2-dimethylaminophenol, 2,4,6-tris (diaminomethyl) phenol, boron trifluoride ethylamine complex, etc. can give.

  The (meth) acrylate resin refers to an organic compound having at least two acrylate groups and / or methacrylate groups. These (meth) acrylate resins can be used alone or in admixture of two or more. The (meth) acrylate resin used in the present invention is generally used after being cured by heating or light irradiation in the presence of a polymerization initiator. Specific examples of the acrylate resin include dicyclopentadienyl diacrylate, norbornane dimethylolpropane diacrylate, neopentyl-modified trimethylolpropane diacrylate, and the like.

As the glass cloth used in the present invention, glass fiber having no absorption in the visible light region is used. The type of glass is not particularly limited, and examples thereof include E glass, C glass, A glass, S glass, D glass, NE glass, T glass, and quartz glass, among which S glass, T glass, and NE glass are easily available. E glass is preferred. Also, by applying surface treatment to the glass cloth by washing with a suitable silane coupling agent, various surfactants, inorganic acids, etc., the wettability, affinity and adhesion at the interface between the glass cloth and the resin can be improved. it can.
The thickness, woven density, and woven structure of the glass cloth are selected according to the intended silicone-based cured sheet. In order to improve the resin impregnation property and surface unevenness, it is an effective technique to physically open the glass cloth yarn bundle.

  The glass cloth composite transparent resin sheet (c) of the present invention needs to be transparent in order to be used for a display element substrate. For that purpose, the difference in refractive index between the silicone-based curable resin (a) and the glass cloth (b) needs to be small. The refractive index here refers to a value measured using sodium D line (wavelength 589 nm). The difference in refractive index between the silicone curable resin (a) and the glass cloth (b) is preferably 0.02 or less, more preferably 0.01 or less. When the difference in refractive index is larger than 0.02, the glass cloth composite transparent resin sheet (c) is opaque due to scattering of light transmitted through the resin at the interface between the silicone-based curable resin (a) and the glass cloth (b). Thus, the parallel light transmittance value is also lowered.

  The manufacturing method of the glass cloth composite transparent resin sheet of this invention is not specifically limited. For example, a method in which a silicone resin, a curable resin, and a curing agent are mixed at room temperature, impregnated into a glass cloth, cast into a necessary mold, and then cured by heating and / or light irradiation. For example, a resin and a curing agent are diluted with a solvent to adjust the viscosity, impregnated into a glass cloth, and after removing the solvent, the resin is cured by heating and / or irradiation with light. For the heating at that time, it is preferable to use a press molding machine, a vacuum press molding machine or the like because the curing reaction and the sheet molding reaction can be performed simultaneously.

  Hereinafter, the present invention will be described more specifically with reference to production examples, examples, and comparative examples, but the present invention is not limited to the following examples. In addition, the measuring method of various physical properties of resin and a glass cloth composite transparent resin sheet is as follows.

[Measurement of weight average molecular weight]
It measured by polystyrene conversion using Tosoh GPC (gel permeation chromatography) HLC-8220.
[Measurement of refractive index]
A refractive index with a wavelength of 589 nm was measured at 23 ° C. using an Abbe refractometer DR-M2 manufactured by Atago.
[Measurement of dynamic viscoelasticity spectrum]
Using a rheometric RSAII, the temperature was raised from 30 ° C. to 300 ° C. at a rate of 5 ° C. per minute, and the storage elastic modulus E ′ of the sample was measured. The distance between chucks was 20 to 30 mm, the sample width was 2 to 4 mm, the measurement frequency was 1 Hz, the amount of strain was 0.05%, and the measurement was performed in the tensile mode.

[Measurement of linear expansion coefficient]
Using TMA / SS120 manufactured by Seiko Instruments Inc., the temperature was increased from 30 ° C. to 330 ° C. at a rate of 5 ° C. per minute, and the linear expansion coefficient was measured. The distance between chucks was 1 mm, the sample width was 2 mm, and the load was 10 g. According to the following formula, the change rate ΔL of the average sample length between 50 ° C. and 300 ° C. was defined as the linear expansion coefficient.
ΔL = (L ₃₀₀ −L ₅₀ ) / L ₅₀ / (300−50)
However, the sample length at 50 ° C. is L ₅₀ , and the sample length at 300 ° C. is L ₃₀₀ .

[Production Example 1] (Production Example 1 of Silicone Resin)
3-glycidoxypropyltrimethoxysilane (50.0 g), water (11.44 g), dibutyltin dilaurate (0.535 g) and tetrahydrofuran (25.0 g) were charged into a 200 ml two-necked flask and reacted at 80 ° C. for 5 hours. After completion of the reaction, 37.9 g of a silicone resin (hereinafter referred to as SR-1) was obtained by removing the solvent under reduced pressure at 80 ° C. for 1 hour. The weight average molecular weight of the obtained compound was 1300, and the epoxy equivalent was 188.

[Production Example 2] (Production Example 2 of Silicone Resin)
30.0 g of 3-glycidoxypropyltrimethoxysilane, 25.2 g of phenyltrimethoxysilane, 13.7 g of water, 2.34 g of formic acid and 27.6 g of toluene were charged into a 200 ml two-necked flask, Reacted for hours. After completion of the reaction, 41.5 g of a silicone resin (hereinafter referred to as SR-2) was obtained by removing the solvent under reduced pressure at 80 ° C. for 1 hour. The weight average molecular weight of the obtained compound was 3000, and the epoxy equivalent was 408.

[Production Example 3] (Production Example 3 of Silicone Resin)
3-glycidoxypropyltrimethoxysilane (30.0 g), phenyltrimethoxysilane (32.7 g), water (13.7 g), formic acid (3.14 g) and tetrahydrofuran (30 g) were charged into a 300 ml two-necked flask and placed in a 70 ° C. oil bath. The mixture was refluxed and reacted for 3 hours. After completion of the reaction, the reaction mixture was concentrated under reduced pressure to obtain 53.9 g of a tetrahydrofuran solution of a silicone resin (hereinafter referred to as SR-3). The weight average molecular weight of the obtained compound was 1800, and the epoxy equivalent was 401.

[Production Example 4] (Production Example 1 of cured silicone-based curable resin)
0.96 g of the silicone resin (SR-1) synthesized in Production Example 1 and 0.96 g of a hydrogenated bisphenol A type epoxy resin (Epicron EXA-7015 manufactured by Dainippon Ink & Chemicals, Inc.) are mixed at room temperature, and A mixed solution (hereinafter referred to as RW-1) obtained by rapidly mixing 0.48 g of 4′-diaminodiphenylmethane (manufactured by Wako Pure Chemical Industries, Ltd.) at room temperature was sandwiched between spacers having a thickness of 200 μm, and the inside of the press machine Then, while maintaining the pressure at 5 MPa, a cured silicone-based curable resin was obtained by thermosetting at a temperature of 150 ° C. for 1 hour and further at a temperature of 200 ° C. for 1 hour. The obtained silicone-based curable resin cured product was 200 μm in thickness and 1.524 in refractive index, and was transparent. Further, when the dynamic viscoelasticity of the cured silicone-based curable resin was measured, the storage elastic modulus E ₀ ′ ₃₅ at 35 ° C. was 1.36 × 10 ⁹ N / m ² and stored at 290 ° C. The elastic modulus E ₀ ' ₂₉₀ was 3.49 × 10 ⁸ N / m ² . E _{0 '35} / E ₀ ' ₂₉₀ = 3.9. A chart of the dynamic viscoelastic spectrum is shown in FIG.

[Example 1]
Impregnated with a mixed solution (RW-1) of a silicone resin, an epoxy resin and a curing agent produced by the method of Production Example 4 into a 100 μm thick T glass-based glass cloth (Nittobo, refractive index 1.520), While maintaining the pressure at 5 MPa in the press, the glass cloth composite resin sheet was obtained by thermosetting at a temperature of 150 ° C. for 1 hour and further at a temperature of 200 ° C. for 1 hour. The obtained glass cloth composite resin sheet had a thickness of 100 μm, a refractive index of 1.524, and was transparent. Moreover, when the dynamic viscoelasticity of this glass cloth composite resin sheet was measured, the storage elastic modulus E ₁ ′ ₃₅ at 35 ° C. was 4.73 × 10 ⁹ N / m ² , and the storage elasticity at 290 ° C. The rate E ₁ ′ ₂₉₀ was 4.17 × 10 ⁹ N / m ² . E _{1 '35} / E ₁ ' ₂₉₀ = 1.13. A dynamic viscoelastic spectrum chart is shown in FIG. The linear expansion coefficient was 18 ppm / K.

[Production Example 5] (Production Example 2 of cured silicone-based curable resin)
0.58 g of the silicone resin (SR-2) synthesized in Production Example 2 and 1.36 g of bisphenol A type epoxy resin (Epicoat 828 manufactured by Japan Epoxy Resin Co., Ltd.) are mixed at room temperature, and 4,4′-diaminodicyclohexylmethane is further mixed. (Made by Wako Pure Chemical Industries, Ltd.) A mixed solution (hereinafter referred to as RW-2) obtained by quickly mixing 0.46 g at room temperature is sandwiched in a spacer having a thickness of 200 μm and maintained at a pressure of 5 MPa in a press machine. While curing at a temperature of 150 ° C. for 1 hour and further at a temperature of 200 ° C. for 1 hour, a cured silicone-based curable resin was obtained. The obtained cured silicone-based curable resin had a thickness of 200 μm, a refractive index of 1.563, and was transparent. Further, this was measured dynamic viscoelasticity of the silicone-based curable resin cured product storage modulus E _{0 '35} at 35 ° C. is ^{1.53 × 10 9 N / m 2} , storage at 290 ° C. The elastic modulus E ₀ ′ ₂₉₀ was 3.27 × 10 ⁸ N / m ² . E _{0 '35} / E _0' is a ₂₉₀ = 4.66.

[Example 2]
A mixed solution RW-2 of a silicone resin, an epoxy resin and a curing agent produced by the method of Production Example 5 was impregnated into an E glass-based glass cloth (manufactured by Nittobo, refractive index 1.560) having a thickness of 100 μm. Then, while maintaining the pressure at 5 MPa, a glass cloth composite resin sheet was obtained by thermosetting at a temperature of 150 ° C. for 1 hour and further at a temperature of 200 ° C. for 1 hour. The obtained glass cloth composite resin sheet had a thickness of 100 μm, a refractive index of 1.563, and was transparent. The measured dynamic viscoelasticity of the glass cloth composite resin sheet, the storage modulus E _{1 '35} at 35 ° C. is ^{5.37 × 10 9 N / m 2} , the storage elasticity at 290 ° C. The rate E ₁ ′ ₂₉₀ was 4.17 × 10 ⁹ N / m ² . E _{1 '35} / E ₁ ' ₂₉₀ = 1.29.
The linear expansion coefficient was 13 ppm / K.

[Production Example 6] (Production Example 1 of cured epoxy resin)
1.92 g of hydrogenated bisphenol A type epoxy resin (Dainippon Ink Chemical Co., Ltd. Epiklone EXA-7015) was mixed at room temperature, and 4,4′-diaminodicyclohexylmethane (Wako Pure Chemical Industries, Ltd.) A mixed solution (hereinafter referred to as RW-3) obtained by rapidly mixing 48 g at room temperature was sandwiched between spacers having a thickness of 200 μm and maintained at a pressure of 5 MPa in a press machine at a temperature of 150 ° C. for 1 hour, and further at a temperature of 200 A cured epoxy resin was obtained by thermosetting at 1 ° C. for 1 hour. The obtained cured epoxy resin had a thickness of 210 μm, a refractive index of 1.523, and was transparent. Further, when the dynamic viscoelasticity of the cured epoxy resin was measured, the storage elastic modulus E ₀ ′ ₃₅ at 35 ° C. was 1.95 × 10 ⁹ N / m ² , and the storage elastic modulus E at 290 ° C. ₀ ′ ₂₉₀ was 3.36 × 10 ⁴ N / m ² . E _{0 '35} / E ₀ ' ₂₉₀ = 5.8 × 10 ⁴ . A chart of the dynamic viscoelastic spectrum is shown in FIG.

[Comparative Example 1]
A mixed solution (RW-3) of an epoxy resin and a curing agent produced by the method of Production Example 6 was impregnated into a 100 μm-thick T glass-based glass cloth (manufactured by Nittobo Co., Ltd., refractive index 1.520). While maintaining the pressure at 5 MPa, a glass cloth composite epoxy resin sheet was obtained by thermosetting at a temperature of 150 ° C. for 1 hour and further at a temperature of 200 ° C. for 1 hour. The obtained glass cloth composite epoxy resin sheet had a thickness of 100 μm, a refractive index of 1.523, and was transparent. Further, when the dynamic viscoelasticity of this glass cloth composite epoxy resin sheet was measured, the storage elastic modulus E ₁ ′ ₃₅ at 35 ° C. was 7.93 × 10 ⁹ N / m ² and stored at 290 ° C. The elastic modulus E ₁ ′ ₂₉₀ was 9.65 × 10 ⁸ N / m ² . E _{1 '35} / E ₁ ' ₂₉₀ = 8.2. A chart of the dynamic viscoelastic spectrum is shown in FIG. It is clear that the glass cloth composite epoxy resin sheet prepared in this comparative example has a large change in storage elastic modulus as compared with Example 1 and Example 2. The linear expansion coefficient was 22 ppm / K.

[Production Example 7] (Production Example 3 of cured silicone-based curable resin)
1.50 g of a tetrahydrofuran solution of the silicone resin (SR-3) synthesized in Production Example 3 and 1.20 g of a hydrogenated bisphenol A type epoxy resin (Epicron EXA-7015 manufactured by Dainippon Ink Chemical Co., Ltd.) are mixed at room temperature. Furthermore, 1.32 g of cationic polymerization catalyst 2-butenyl-1,4-butene-sulfonium hexafluoroantimato (trade name “Adeka Opton CP-66” manufactured by Asahi Denka Kogyo Co., Ltd.) is obtained by quickly mixing at room temperature. The mixed solution (hereinafter referred to as RW-4) was sandwiched between 200 μm thick spacers and dried in a dryer at 100 ° C. for 2 hours. Then, a silicone-based curable resin sheet was obtained by thermosetting at a temperature of 150 ° C. for 1 hour and further at a temperature of 200 ° C. for 1 hour while maintaining the pressure at 5 MPa in the press. The obtained cured silicone-based curable resin was 200 μm in thickness and 1.522 in refractive index, and was transparent. Further, this was measured dynamic viscoelasticity of the silicone-based curable resin cured product storage modulus E _{0 '35} at 35 ° C. is ^{1.18 × 10 9 N / m 2} , storage at 290 ° C. The elastic modulus E ₀ ' ₂₉₀ was 1.26 × 10 ⁸ N / m ² . E _{0 '35} / E ₀ ' ₂₉₀ = 8.9. A dynamic viscoelastic spectrum chart is shown in FIG. The linear expansion coefficient was 15 ppm / K.

[Comparative Example 2]
A mixed solution (RW-4) of an epoxy resin and a curing agent produced by the method of Production Example 7 was impregnated into a 100 μm-thick T glass-based glass cloth (manufactured by Nittobo Co., Ltd., refractive index 1.520). Dry in a dryer for 2 hours. Then, a glass cloth composite silicone-based curable resin sheet was obtained by thermosetting at a temperature of 150 ° C. for 1 hour and further at a temperature of 200 ° C. for 1 hour while maintaining the pressure at 5 MPa in a press. The obtained glass cloth composite silicone-based curable resin sheet had a thickness of 100 μm, a refractive index of 1.522, and was transparent. Also, the dynamic viscoelasticity of the glass cloth composite silicone based curable resin sheet was measured, the storage modulus E _{1 '35} at 35 ° C. is ^{6.95 × 10 9 N / m 2} , 290 ℃ The storage elastic modulus E ₁ ' ₂₉₀ was 3.71 × 10 ⁸ N / m ² . E _{1 '35} / E ₁ ' ₂₉₀ = 1.9. A chart of the dynamic viscoelastic spectrum is shown in FIG.
The above evaluation results are shown in Table 1.

  The glass cloth composite transparent resin sheet of the present invention can be suitably used in the fields of liquid crystal display element substrates, organic EL display element substrates, color filter substrates, touch panel substrates, and solar cell substrates.

10 is a dynamic viscoelasticity spectrum chart according to Production Example 4. 2 is a dynamic viscoelastic spectrum chart according to Example 1. FIG. 10 is a dynamic viscoelasticity spectrum chart according to Production Example 6. 4 is a chart of a dynamic viscoelastic spectrum according to Comparative Example 1. 10 is a dynamic viscoelastic spectrum chart according to Production Example 7. 10 is a chart of a dynamic viscoelastic spectrum according to Comparative Example 2.

Claims (4)

A glass cloth composite transparent resin sheet obtained by compounding a silicone curable resin (a) having a silicone resin (a-1) and a curable resin (a-2) as constituent elements and a glass cloth (b). In (c), the relationship of the storage elastic modulus of the silicone-based curable resin (a) in the dynamic viscoelasticity measurement satisfies the following formula, and the refractive index of the silicone-based curable resin (a) and the glass cloth (b) A glass cloth composite transparent resin sheet, wherein the difference is 0.02 or less.
E _{0 '35} / E ₀ ' ₂₉₀ ≦ 8
However,
E _{0 '35:} dynamic storage modulus of the silicone-based curable resin at 35 ° C. in viscoelasticity measurement E _{0' 290:} the storage modulus of the silicone-based curable resin at 290 ° C. in a dynamic viscoelasticity measurement A glass cloth composite transparent resin sheet obtained by compounding a silicone curable resin (a) having a silicone resin (a-1) and a curable resin (a-2) as constituent elements and a glass cloth (b). In (c), the relationship of the storage elastic modulus of the glass cloth composite transparent resin sheet (c) in the dynamic viscoelasticity measurement satisfies the following formula, and the silicone curable resin (a) and the glass cloth (b) A glass cloth composite transparent resin sheet having a refractive index difference of 0.02 or less.
E _{1 '35} / E ₁ ' ₂₉₀ ≦ 1.5
However,
E _{1 '35:} dynamic viscoelasticity storage modulus E ₁ of the glass cloth composite transparent resin sheet at 35 ° C. in the measurement' _290: storage of the glass cloth composite transparent resin sheet at 290 ° C. in a dynamic viscoelasticity measurement Elastic modulus   The glass cloth composite transparent according to claim 1 or 2, wherein the silicone resin (a-1) is a silicone resin having an epoxy group, and the curable resin (a-2) is an epoxy resin. Resin sheet.   The silicone resin (a-1) is a silicone resin having an epoxy group, the curable resin (a-2) is an epoxy resin, and a polyfunctional amine curing agent is used as a curing agent in the production of the sheet. The glass cloth composite transparent resin sheet according to any one of claims 1 to 3, wherein

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