KR20140105575A - Glass fiber composite resin substrate - Google Patents

Abstract

A glass fiber composite resin substrate comprising a curable resin composition and glass fiber,
Wherein the curable resin composition comprises
(A) a basket-like silsesquioxane resin having at least one group selected from the group consisting of a (meth) acryloyl group, a glycidyl group and a vinyl group,
(B) the following general formulas (1) to (2):
-R ¹ -CR ² = CH ₂ - (One)
-CR ² = CH ₂ - (2)
[In the formula (1), R ¹ represents any one selected from the group consisting of an alkylene group, an alkylidene group and an -OCO- group. In the formulas (1) to (2), R ² independently represents a hydrogen atom or an alkyl group .]
An unsaturated compound other than the cage silsesquioxane resin having two or more unsaturated functional groups selected from the group consisting of
(C) Curing catalyst
, Wherein the content of the cage silsesquioxane resin (A) in the curable resin composition is 5 to 90 mass% with respect to the total curable resin composition.

Description

[0001] GLASS FIBER COMPOSITE RESIN SUBSTRATE [0002]

The present invention relates to a glass fiber composite resin substrate.

Glass has a feature of being excellent in transparency, heat resistance, low thermal expansion, chemical stability, and has been widely used as an optical glass such as a lens, an optical disk and a display substrate, and contributes to the development of industry. In recent years, along with the reduction in weight of various optical devices, it has been studied to reduce the thickness and weight of the optical glass having a large specific gravity. However, the glass has the drawback that it is fragile due to impact and is fragile, and when it is thinned, its mechanical strength is further lowered, and thus the yield due to cracking during the production process is lowered.

Japanese Unexamined Patent Application Publication No. 2004-50565 (Patent Document 1), for example, discloses a thin film substrate which is excellent in flexibility and heat resistance and improved in fragility, and includes a metal oxide polymer containing an organic group as a main component A thin film sheet-like substrate obtained by laminating a resin layer on the surface of a glass substrate is described. However, since plate-like glass is used for such a thin film sheet-like substrate, it is difficult to further reduce the weight, and the mechanical strength is still insufficient.

In recent years, a transparent plastic has attracted attention as an optical member that can be substituted for glass, from the viewpoint of light workability and excellent workability in which thinning is easy. Examples of such transparent plastics include polymethylmethacrylate (PMMA), alicyclic polyolefin, epoxy resin, and silicone resin. Among them, PMMA and alicyclic polyolefin are called organic glass because they have particularly excellent transparency, And a light guide plate of a liquid crystal display, an optical disk, and the like. However, for example, when a low-resistance transparent electrode is formed on a flexible substrate or an active element such as a TFT is formed, a temperature of at least 300 DEG C to 350 DEG C is required, whereas a resin such as PMMA has a lower heat resistance than glass, As shown in Fig. Further, since a material made of such a resin has a large coefficient of linear expansion, there is a large difference between the coefficient of linear expansion in a device material such as a transparent electrode and a TFT, and a crack or a broken line is generated due to this difference there was.

Thus, as a method of improving heat resistance and coefficient of linear expansion of a material, a method of combining resin and glass fiber has been developed. For example, Japanese Unexamined Patent Application Publication No. 2004-231934 (Patent Document 2) and Japanese Unexamined Patent Application Publication No. 2004-51960 (Patent Document 3) disclose that glass fibers such as glass cloth and Abbe's number A composite resin obtained by compounding a curable resin such as an epoxy resin or an acrylate resin having a refractive index close to that of the glass fiber.

Japanese Patent Application Laid-Open No. 2004-50565 Japanese Patent Application Laid-Open No. 2004-231934 Japanese Patent Application Laid-Open No. 2004-51960

However, in the composite resin as described in Patent Documents 2 and 3, the heat resistance to heat up to about 250 DEG C is somewhat improved, but the glass transition temperature is less than 300 DEG C, The present inventors have found that it is still difficult to stably and uniformly laminate an inorganic material layer such as a device material because the elastic modulus of the substrate is increased and the substrate is expanded or deformed when heated to a temperature higher than the transition temperature.

It is an object of the present invention to provide a glass fiber composite resin substrate having a high level of heat resistance and transparency and having a sufficiently small thermal expansion coefficient.

DISCLOSURE OF THE INVENTION The inventors of the present invention have conducted intensive researches to achieve the above object. As a result, the present inventors have found that in a glass fiber composite resin substrate composed of a curable resin composition and glass fiber, the (meth) acryloyl group, the glycidyl group, Group, a specific unsaturated compound having at least two unsaturated functional groups containing a carbon-carbon double bond, and a curing catalyst, wherein the specific cage silsesquioxane resin has at least one kind of group selected from the group consisting of It has been found that a glass fiber composite resin substrate having a high degree of heat resistance and transparency and sufficiently low thermal expansion coefficient can be obtained by using the curable resin composition having a content of the cage silsesquioxane resin within a specific range, I have come to completion.

That is, in the glass fiber composite resin substrate of the present invention,

A glass fiber composite resin substrate comprising a curable resin composition and glass fiber,

Wherein the curable resin composition comprises

(A) a basket-like silsesquioxane resin having at least one group selected from the group consisting of a (meth) acryloyl group, a glycidyl group and a vinyl group,

(B) the following general formulas (1) to (2):

-R ¹ -CR ² = CH ₂ - (One)

-CR ² = CH ₂ - (2)

[In the formula (1), R ¹ represents any one selected from the group consisting of an alkylene group, an alkylidene group and an -OCO- group. In the formulas (1) to (2), R ² independently represents a hydrogen atom or an alkyl group .]

An unsaturated compound other than the cage silsesquioxane resin having two or more unsaturated functional groups selected from the group consisting of

(C) Curing catalyst

, And the content of the cage-like silsesquioxane resin (A) is 5 to 90 mass% with respect to the total curable resin composition.

As the glass fiber composite resin substrate of the present invention, the cage-like silsesquioxane resin (A)

^{_{[R 3 SiO 3/2]}} n [R 4 SiO 3/2] m ... (3)

(3), R ³ represents an organic group having a group selected from the group consisting of a (meth) acryloyl group, a glycidyl group and a vinyl group, R ⁴ represents a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, (I) to (iii): wherein R 1, R 2, R 3, R 4 and R 5 are the same or different,

n? 1 ... (i)

m? 0 ... (ii)

n + m = h ... (iii)

[Wherein h in the formula (iii) represents an integer selected from the group consisting of 8, 10, 12 and 14]

, And when n and m are each 2 or more, R ³ and R ⁴ may be the same or different.

Is preferably a basket-like silsesquioxane resin.

In the glass fiber composite resin substrate of the present invention, the ratio (n: m) of n to m in the general formula (3) is preferably 10: 0 to 4: 6, Of the cage-like silsesquioxane resin is 50 mass% or more with respect to the total of the cage-like silsesquioxane resin (A).

In the glass fiber composite resin substrate of the present invention, it is preferable that the unsaturated functional group of the unsaturated compound (B) is at least one group selected from the group consisting of an acryloyl group, a methacryloyl group, an allyl group and a vinyl group , And the number of the unsaturated functional groups of the unsaturated compound (B) is preferably 2 to 10 per one molecule of the compound.

Further, as the glass fiber composite resin substrate of the present invention, it is preferable that the curable resin composition is cured after impregnating the glass fiber with the curable resin composition. The mass ratio of the cured product of the curable resin composition and the glass fiber (mass of the cured product: mass of the glass fiber) is preferably 20:80 to 70:30, and more preferably 0.03 to 0.5 mm.

According to the present invention, it becomes possible to provide a glass fiber composite resin substrate having a high level of heat resistance and transparency and sufficiently low in thermal expansion coefficient.

Hereinafter, the present invention will be described in detail based on its preferred embodiments. In the glass fiber composite resin substrate of the present invention,

A glass fiber composite resin substrate comprising a curable resin composition and glass fiber,

Wherein the curable resin composition comprises

(A) a basket-like silsesquioxane resin having at least one group selected from the group consisting of a (meth) acryloyl group, a glycidyl group and a vinyl group,

(B) an unsaturated compound other than the cage silsesquioxane resin having two or more unsaturated functional groups selected from the group consisting of the group represented by the general formula (1) and the group represented by the general formula (2) And

(C) Curing catalyst

, And the content of the cage-like silsesquioxane resin (A) is 5 to 90 mass% with respect to the total curable resin composition.

≪ (A) Basket-like silsesquioxane resin >

In the present invention, the cage-like silsesquioxane resin refers to a siloxane having a completely closed polyhedral structure or a siloxane in which a part of -Si-O-Si- bond is cleaved in the polyhedral structure, Or an oligomer obtained by polymerizing a sesquioxane resin as a monomer. The basket-like silsesquioxane resin according to the present invention has at least one group selected from the group consisting of a (meth) acryloyl group, a glycidyl group and a vinyl group (hereinafter occasionally referred to as a curable functional group) . As the curable functional group, it is preferable that the curable functional group is bonded to the silicon atom disposed at the apex of the cage-like silsesquioxane skeleton, directly or via a divalent organic group. Examples of the divalent organic group include an alkylene group and a phenylene group. In the present invention, (meth) acryloyl group means methacryloyl group and acryloyl group.

From the viewpoint that the cross-linking density of the curable resin composition becomes higher and the heat resistance of the glass fiber composite resin substrate tends to further improve, the cage-like silsesquioxane resin according to the present invention is preferably a cage-like silsesquioxane skeleton- It is preferable that the curable functional groups are bonded to all of the vertices and that the molecular weight distribution and the molecular structure are controlled, and some of the curable functional groups may be substituted with another group such as an alkyl group or a phenyl group. When some of the curable functional groups are substituted with other groups, the cage silsesquioxane resin according to the present invention preferably has a molar ratio of the curable functional group to the other groups Average number of moles of functional groups]: [average number of moles of other groups]) is preferably 10: 0 to 6: 4. In the present invention, the ratio of the number of curable functional groups in the cage-like silsesquioxane resin to the number of other groups was determined by ¹ H-NMR (JNM-ECA 400 (manufactured by Nippon Denshoku Co., Ltd.) Solvent: chloroform-d, temperature: 22.7 占 폚, 400 MHz), and the peaks of other group peaks.

Further, as the cage-like silsesquioxane resin according to the present invention, a cross-linked structure having a rigid structure is formed, so that the resulting glass fiber composite resin substrate has improved heat resistance and tends to have a smaller thermal expansion coefficient (3): < EMI ID =

^{_{[R 3 SiO 3/2]}} n [R 4 SiO 3/2] m ... (3)

Is a cage-like silsesquioxane resin having a closed polyhedron structure.

In the above formula (3), R ³ represents an organic group having any one group selected from the group consisting of a (meth) acryloyl group, a glycidyl group and a vinyl group. Examples of such an organic group include a (meth) acryloyl group; Glycidyl group; Vinyl group; (Meth) acryloyl group, a glycidyl group or a group in which a vinyl group is bonded to a divalent hydrocarbon group such as an alkylene group or a phenylene group. The alkylene group may be straight chain or branched chain and preferably has 1 to 3 carbon atoms from the viewpoint that the bonding distance is short and the heat resistance of the resultant glass fiber composite resin substrate tends to be further improved. Examples of the phenylene group include an unsubstituted phenylene group and a 1,2-phenylene group having a lower alkyl group. Among these, from the viewpoint of availability of raw materials, an alkylene group having 1 to 3 carbon atoms is more preferable and a propylene group is more preferable in view of obtaining a glass fiber composite resin substrate having a higher crosslinking density desirable.

Specific examples of R ³ include a methacryloxypropyl group, a glycidoxypropyl group and an epoxycyclohexyl group. Among them, a methacryloxypropyl group is preferable from the viewpoint of availability of raw materials and high polymerization reactivity .

In the formula (3), R ⁴ represents any one selected from the group consisting of a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, and an alkylsiloxy group having 1 to 20 carbon atoms. The hydrocarbon group having 1 to 20 carbon atoms may be linear, branched or cyclic. Examples of the hydrocarbon group include an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, a cycloalkenyl group having 3 to 20 carbon atoms, a phenyl group, . The alkyl group having 1 to 20 carbon atoms may be linear or branched and is preferably a straight chain alkyl group having 2 to 10 carbon atoms from the viewpoint of obtaining a framework silk silsesquioxane skeleton. Examples of the cycloalkyl group having 3 to 20 carbon atoms include a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclohexylethyl group. Of these, Cyclohexyl group is preferred. As the cycloalkenyl group having 3 to 20 carbon atoms, for example, a cyclopentenyl group, a cyclohexenyl group and the like can be given, and a cyclopentenyl group is preferable from the viewpoint of easy availability. Examples of the alkoxy group having 1 to 20 carbon atoms include a methoxy group, an ethoxy group and an isopropyl group, and among them, a methoxy group is preferable from the viewpoint of high reactivity. Examples of the alkylsiloxy group having 1 to 20 carbon atoms include a trimethylsiloxy group, a triethylsiloxy group, a triphenylsiloxy group, a dimethylsiloxy group, and a t-butyldimethylsiloxy group. Of these, R < ⁴ > is more preferably an alkyl group having 2 to 10 carbon atoms or a phenyl group from the viewpoint of easily obtaining a skeleton of cage silsesquioxane.

In the above formula (3), n and m represent the following formulas (i) to (iii):

n? 1 ... (i)

m? 0 ... (ii)

n + m = h ... (iii)

[Wherein h in the formula (iii) represents an integer selected from the group consisting of 8, 10, 12 and 14]

Lt; / RTI > Since the cage silsesquioxane resin according to the present invention has at least one curable functional group by satisfying the condition represented by the above formula (i), the radical curing of the cage silsesquioxane resin with the unsaturated compound (B) It is possible to obtain a glass fiber composite resin substrate having heat resistance and transparency and having a sufficiently small thermal expansion coefficient. Further, when n and m satisfy the conditions represented by the above formula (iii), the cage-like silsesquioxane resin according to the present invention has a cage structure almost completely condensed, Structure, a high level of heat resistance and transparency and a sufficiently small thermal expansion coefficient can be achieved in the glass fiber composite resin substrate. When n and m are each 2 or more, R ³ and R ⁴ may be the same or different.

In the cage-like silsesquioxane resin according to the present invention, the ratio (n: m) of n and m is preferably 10: 0 to 4: 6, more preferably 10: 0 to 5: 5 . When the number of m with respect to n exceeds the upper limit, the cross-linking density of the glass fiber composite resin substrate decreases and the heat resistance tends to decrease or the thermal expansion coefficient tends to become large.

In the present invention, the ratio (n: m) of n to m, that is, the ratio of the number of curable functional groups bonded to the vertex of the polyhedron of the cage-like silsesquioxane resin to the number of other groups .

Further, as the cage-like silsesquioxane resin according to the present invention, a cross-linked structure having a rigid structure is formed, so that the resulting glass fiber composite resin substrate has improved heat resistance and tends to have a smaller thermal expansion coefficient , The cage silsesquioxane resin represented by the above formula (3) is preferably not less than 50% by mass, more preferably not less than 70% by mass, based on the whole cage silsesquioxane resin according to the present invention Do.

As a method for obtaining such a basket-like silsesquioxane resin, for example, the following general formula (4):

R ³ SiX ₃ ... (4)

[Formula (4) in R ³ is the formula (3) in R ³ and are of the same definition, X is an alkoxy group, an acetoxy group, hydrolysis of any one member selected from the group consisting of a halogen atom and a hydroxyl group .]

(A) represented by the following general formula (5): "

R ⁴ SiX ₃ ... (5)

Wherein R ⁴ has the same definition as R ⁴ in the general formula (3), and X has the same definition as X in the general formula (4).

(B) in the presence of water, an organic polar solvent and a basic catalyst.

In the formulas (4) and (5), each X is independently a hydrolyzable group selected from the group consisting of an alkoxy group, an acetoxy group, a halogen atom and a hydroxy group. The hydrolyzable group is preferably an alkoxy group. Examples of the alkoxy group include a methoxy group, ethoxy group, n- and i-propoxy group, n-, i- and t-butoxy groups and methoxy group is preferable from the viewpoint of high reactivity.

Examples of the silicon compound (a) include, for example, methacryloxymethyltriethoxysilane, methacryloxymethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane , 3-acryloxypropyltrimethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, p-styryltrimethoxysilane, p-styryltriethoxysilane, vinyltrimethoxysilane, vinyltri 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane. Of these, 3-methacryloxypropyltrimethoxysilane and 3-acryloxypropyltrimethoxysilane are preferable as the silicon compound (a) from the viewpoint of availability of raw materials. As the silicon compound (a), one type may be used alone, or two or more types may be used in combination.

Examples of the silicon compound (b) include phenyltrimethoxysilane, phenyltriethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane butyltrimethoxysilane, n-butyltrimethoxysilane, t-butyltrimethoxysilane, t-butyltriethoxysilane, n-octyltrimethoxysilane, n-octyltriethoxysilane, . As the silicon compound (b), one type may be used alone, or two or more types may be used in combination.

The mixing ratio (a: b) of the silicon compound (a) and the silicon compound (b)

a: b = n: m ... (vi)

[In the formula (vi), n and m have the same definitions as n and m in the formula (3).]

Is satisfied.

The water should be at least a mass sufficient for the hydrolyzable groups in the silicon compounds (a) and (b) to hydrolyze, and the number of hydrolyzable groups calculated from the mass of the silicon compounds (a) and (b) It is preferably a mass corresponding to 1.0 to 1.5 times the molar amount of the theoretical amount (mol). As the water, water contained in an aqueous solution of a basic catalyst described later may be used as it is.

Examples of the organic polar solvent include alcohols such as methanol, ethanol and 2-propanol; Acetone; Tetrahydrofuran, and the like. Any one of them may be used alone, or two or more of them may be used in combination. Of these, from the viewpoint that a cage-like silsesquioxane skeleton is efficiently formed, it is preferable to use a lower alcohol having 1 to 6 carbon atoms which is soluble in water, more preferably 2-propanol.

Examples of the basic catalyst include alkali metal hydroxides such as potassium hydroxide, sodium hydroxide and cesium hydroxide; And ammonium hydroxide salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, benzyltrimethylammonium hydroxide and benzyltriethylammonium hydroxide. As the basic catalyst according to the present invention, any one of them may be used alone, or two or more of them may be used in combination. Among them, it is preferable to use tetramethylammonium hydroxide from the viewpoint of high catalytic activity. The amount of the basic catalyst is preferably 0.1 to 10% by mass based on the total mass of the silicon compounds (a) and (b). Further, since the basic catalyst is usually used as an aqueous solution, water contained in an aqueous solution of the basic catalyst may be used as the water.

In the hydrolysis, the reaction time is preferably 2 hours or more, and the reaction temperature is preferably 0 to 50 ° C, more preferably 20 to 40 ° C. When the reaction time and the reaction temperature are lower than the lower limit, the hydrolyzable groups tend to remain unreacted. On the other hand, when the reaction temperature exceeds the above-mentioned upper limit, the reaction rate becomes too fast, so that a complicated condensation reaction proceeds and consequently the high molecular weight of the hydrolysis product is promoted.

By this method, a reaction composition containing the cage-like silsesquioxane resin according to the present invention can be obtained. In this reaction composition, the cage-like silsesquioxane resin (full condensation cage-type silsesquioxane resin (for example, the resin represented by the above formula (3)) according to the present invention, Oxane resin), a plurality of kinds of ladder-type silsesquioxane resin and random-type silsesquioxane resin are included as by-products of the reaction. In the reaction composition, the content of the cage-like silsesquioxane resin according to the present invention is preferably from 50% by mass to the total amount of the reaction composition from the viewpoint that the reaction composition can be used as it is as a raw material for the curable resin composition according to the present invention, Or more. The content of the cage-like silsesquioxane resin represented by the formula (3) in the obtained cage-like silsesquioxane resin is preferably 50 mass% or more, more preferably 70 More preferably at least% by mass.

In the present invention, the total content of the cage-like silsesquioxane resin according to the present invention in the composition and the content of the cage silsesquioxane resin represented by the formula (3) mass spectrometry (LC-MS, HPLC: Agilent 1100 Series Systems (Agilent Technology Co., Ltd.), MS: QSTAR ^R XL Hybrid LC / MS / MS System (AB SCIEX Inc.), column: SunFire C18 column, Mobile phase: H ₂ O The structure of the cage-like silsesquioxane resin was determined from the following formula: -CH ₃ CN (30-70), velocity: 1 ml / min, temperature: 40 ° C, detector: UV (254 nm), and gel permeation chromatography (Number average molecular weight) measured by HLC-8320 GPC (Toso Co., Ltd., solvent: THF, column: ultra-high speed semi-SEC column Super H series, temperature: 40 캜, speed: 0.6 ml / min) .

In the present invention, one of these cage silsesquioxane resins may be used singly or in combination of two or more.

<(B) Unsaturated compound>

The unsaturated compound according to the present invention is represented by the following general formulas (1) to (2):

-R ¹ -CR ² = CH ₂ - (One)

-CR ² = CH ₂ - (2)

[In the formula (1), R ¹ represents any one selected from the group consisting of an alkylene group, an alkylidene group and an -OCO- group. In the formulas (1) to (2), R ² independently represents a hydrogen atom or an alkyl group .]

Is a compound other than the cage-like silsesquioxane resin having two or more unsaturated functional groups selected from the group consisting of a group represented by the formula Further, from the group containing the group represented by the formula (2), the group represented by the formula (1) is removed.

In the above formula (1), R ¹ represents any one selected from the group consisting of an alkylene group, an alkylidene group and a -OCO- group. The alkylene group and the alkylidene group may be linear or branched and may preferably have a carbon number of 1 to 6 from the viewpoint that the bonding distance is short and the heat resistance of the obtained glass fiber composite resin substrate tends to be further improved. Among them, the -OCO- group is preferable as R ¹ from the viewpoint that the reactivity of the radical polymerization tends to be high.

In the formulas (1) and (2), R ² independently represents a hydrogen atom or an alkyl group. The alkyl group may be linear or branched, and preferably has 1 to 3 carbon atoms from the viewpoint of better reactivity of radical polymerization. As such R ² , a hydrogen atom or a methyl group is preferable from the viewpoint of more excellent reactivity of radical polymerization.

Specific examples of such an unsaturated functional group include an acryloyl group, a methacryloyl group, an allyl group and a vinyl group. Since the unsaturated compound according to the present invention has such an unsaturated functional group, it is possible to perform radical polymerization with the cage-like silsesquioxane resin (A) having the above-mentioned curable functional group, to have a high level of heat resistance and transparency, The glass fiber composite resin substrate of the present invention having a sufficiently small size can be obtained.

The unsaturated compound according to the present invention has at least two unsaturated functional groups per one molecule of the compound. When the number of the unsaturated functional groups is less than the lower limit described above, radical copolymerization with the cage-like silsesquioxane resin is not carried out sufficiently, so that the modulus of elasticity of the glass fiber composite resin substrate at high temperature is lowered and the heat resistance is lowered . From the viewpoint of further improving the modulus of elasticity and heat resistance, the number of unsaturated functional groups is preferably 2 to 10. The unsaturated compound according to the present invention may be either a monomer or a polymer, and when the unsaturated compound is a polymer, the number of the unsaturated functional groups is an average value per one molecule of the compound. The number (or average number) of unsaturated functional groups per molecule of the compound was measured by ¹ H-NMR (apparatus: JNM-ECA 400 (manufactured by Nippon Denshikushi Co., Ltd., solvent: chloroform-d, temperature: 22.7 캜, (GPC, HLC-8320GPC (manufactured by Tosoh Corporation), solvent: THF, column: super-high speed semi- micro SEC column Super H series, temperature: 40 ° C, speed : 0.6 ml / min).

The unsaturated compound according to the present invention is not particularly limited as long as it has two or more unsaturated functional groups per one molecule of the compound, and preferably has a molecular weight (weight average molecular weight in the case of a polymer) of 80 to 5,000. If the molecular weight is less than the lower limit described above, unreacted unsaturated compounds remain in the curing of the curable resin composition, the unreacted unsaturated compound becomes a volatile component in the heat treatment such as heat treatment, On the other hand, when the amount exceeds the upper limit, the solubility with the cage-like silsesquioxane resin tends to be lowered, and the viscosity of the curable resin composition to be obtained tends to increase, making handling difficult.

Examples of such unsaturated compounds include dicyclopentanyl diacrylate, tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, bisphenol A diglycidyl ether diacrylate, bisphenol fluorene diacrylate, Tetraethylene glycol diacrylate, hydroxypivalic acid neopentyl glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, and the like. From the viewpoint that solubility with the cage silsesquioxane resin is high and the heat resistance of the resultant glass fiber composite resin substrate tends to be further improved, it is preferable that the above-mentioned hydrocarbon compound having 1 to 30 carbon atoms has two or more unsaturated functional groups Bonded compounds are preferred, and dicyclopentanyl di A dimethacrylate, bisphenol fluorene diacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate is more preferable. As the unsaturated compound according to the present invention, one type may be used alone, or two or more types may be used in combination.

&Lt; (C) Curing Catalyst >

The curing catalyst according to the present invention promotes the curing reaction (radical polymerization reaction) between the cage silsesquioxane resin (A) and the unsaturated compound (B). Examples of such a curing catalyst include a radical polymerization initiator, and examples of the radical polymerization initiator include a photo radical polymerization initiator and a thermal radical polymerization initiator.

Examples of the photo radical polymerization initiator include an acetophenone based, benzoin based, benzophenone based, thioxanthone based, and acylphosphine oxide based photopolymerization initiator. Specific examples thereof include trichloroacetophenone, diethoxyacetophenone, 1-phenyl 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropane-1-one, benzo Benzyldimethylketal, benzophenone, thioxanthone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, methylphenylglyoxylate, camphorquinone, benzyl, anthraquinone, Michler's ketone and the like . Examples of the thermal radical polymerization initiator include ketone peroxide, peroxyketal, hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxydicarbonate, peroxy ester, . As the curing catalyst according to the present invention, one kind or two or more kinds of them may be used in combination, or the photo radical polymerization initiator and the thermal radical polymerization initiator may be used in combination.

<Curable resin composition>

The curable resin composition according to the present invention contains the cage silsesquioxane resin (A), the unsaturated compound (B) and the curing catalyst (C).

In the curable resin composition according to the present invention, the content of the cage-like silsesquioxane resin is required to be 5 to 90 mass% with respect to the total curable resin composition. When the content of the cage-like silsesquioxane resin is less than the above lower limit, the glass transition temperature of the glass fiber composite resin substrate is lowered and the thermal expansion coefficient is increased, resulting in insufficient heat resistance. On the other hand, when the upper limit is exceeded, the cross-linking density of the cured product increases and the glass fiber composite resin substrate becomes weak, which makes handling difficult.

The content of the cage silsesquioxane resin is preferably 8 to 80 mass% from the viewpoint that the heat resistance of the glass fiber composite resin substrate is further improved and the strength is further improved. From the same viewpoint as the above, it is preferable that 50% by mass or more (more preferably 70% by mass or more) of the cage silsesquioxane resin is a cage silsesquioxane resin represented by the above formula (3) , The content of the cage silsesquioxane resin represented by the formula (3) in the curable resin composition according to the present invention is preferably 2.5 to 90 mass%, more preferably 5 to 80 mass% Is more preferable.

In the curable resin composition according to the present invention, the content of the unsaturated compound is preferably 5 to 90 mass%, more preferably 10 to 70 mass%, with respect to the total curable resin composition. When the content of the unsaturated compound is less than the above lower limit, the solubility of the curable resin composition is lowered or the solution viscosity is increased, so that the impregnation property with the glass fiber tends to decrease. On the other hand, The glass transition temperature of the cured product of the curable resin composition is lowered and the heat resistance of the resultant glass fiber composite resin substrate tends to be lowered.

In the curable resin composition according to the present invention, the content of the curing catalyst is preferably 0.1 to 5.0 mass%, more preferably 0.1 to 3.0 mass%, with respect to the total curable resin composition. When the content of the curing catalyst is less than the lower limit described above, the curing reaction becomes insufficient and the strength and rigidity of the obtained cured product tend to decrease. On the other hand, when the content exceeds the upper limit, there is a possibility that the cured product is colored .

The curable resin composition according to the present invention may further contain a curable silsesquioxane resin (A) and a curable compound other than the unsaturated compound (B) (hereinafter, occasionally referred to as a curable compound) . Such a curable compound is not particularly limited, but may be a compound having compatibility and reactivity with the cage silsesquioxane resin, as long as it is a compound capable of being cured by heating or irradiation with an active energy ray.

Examples of such a curable compound include a reactive oligomer, which is a polymer having about 2 to 20 repeating structural units, and a reactive monomer having a low molecular weight and a low viscosity. Specific examples of the reactive oligomer include epoxy acrylate, epoxylated oil (acrylate), urethane acrylate, unsaturated polyester, polyester acrylate, polyether acrylate, vinyl acrylate, polyene / thiol, Polybutadiene, and polystyrylethyl methacrylate. Specific examples of the reactive monomer include styrene, vinyl acetate, N-vinylpyrrolidone, butyl acrylate, 2-ethylhexyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, And monofunctional monomers such as acrylate, methacrylate, methacrylate, methacrylate, methacrylate, methacrylate, vinyl acrylate, dicyclopentenyloxyethyl acrylate, phenoxyethyl acrylate and trifluoroethyl methacrylate. These curing compounds may be used singly or in combination of two or more kinds.

When the curable resin composition according to the present invention contains the above-mentioned curable compound, the content thereof is preferably 40% by mass or less based on the total amount of the curable resin composition. When the content of the curable compound exceeds the upper limit, it is difficult to form a sufficient crosslinked structure and the heat resistance of the resultant glass fiber composite resin substrate tends to decrease.

The curable resin composition according to the present invention may further contain various additives within the range not hindering the effect of the present invention. Examples of the additive include organic / inorganic fillers, plasticizers, flame retardants, heat stabilizers, antioxidants, light stabilizers, ultraviolet absorbers, lubricants, antistatic agents, release agents, foaming agents, nucleating agents, coloring agents, . When such an additive is contained, the content thereof is preferably 30 mass% or less with respect to the total curable resin composition.

The curable resin composition according to the present invention may further contain a solvent such as methyl ethyl ketone, toluene, or ethyl acetate for the purpose of adjusting the viscosity etc., The production efficiency is deteriorated and the solvent may remain in the resultant glass fiber composite resin substrate to deteriorate the characteristics of the substrate. Therefore, the content of the solvent is preferably 5% by mass or less based on the total curable resin composition It is more preferable that it does not contain a solvent.

<Glass fiber>

Examples of the form of the glass fiber according to the present invention include thread-like yarn, glass cloth, and nonwoven fabric. Of these, glass cloth is preferable from the viewpoint that the effect of reducing the thermal expansion coefficient is high. As the raw material of the glass cloth, E glass, C glass, A glass, S glass, D glass, NE glass, T glass, quartz glass and the like can be cited according to the composition of the glass. E glass, S glass, T glass and NE glass are preferable from the viewpoint that they are readily available.

The glass fiber according to the present invention may further contain at least one selected from the group consisting of a silane coupling agent, various surfactants, cleansing with an inorganic acid, and the like, for the purpose of improving the wettability, affinity and adhesion at the interface between the curable resin composition and the glass fiber. Corona discharge treatment; Ultraviolet irradiation treatment; It is also possible to use one having been subjected to surface treatment by plasma treatment or the like.

The refractive index of the glass fiber according to the present invention is preferably in the range of -0.02 to +0.02, more preferably in the range of -0.01 to +0.01, from the refractive index of the cured product of the curable resin composition. If the difference in the refractive index deviates from the above range, the interfacial scattering between the cured product of the curable resin composition and the glass fiber increases, and the transparency of the glass fiber composite resin substrate lowers, so that it can be used as a flexible display or a glass substrate for a solar cell It tends to be difficult to do.

When the glass fiber according to the present invention is in the form of a glass cloth or a nonwoven fabric, the thickness of the glass fiber composite resin substrate can be appropriately selected depending on the purpose of use, and the tendency of the curable resin composition to impregnate the glass fiber is improved It is preferably 30 to 100 mu m.

&Lt; Glass fiber composite resin substrate &

The glass fiber composite resin substrate of the present invention is a composite of the curable resin composition and the glass fiber. A method for producing such a glass fiber composite resin substrate is not particularly limited, and for example, a method of curing the curable resin composition after impregnating the glass fiber with the curable resin composition may be mentioned.

In this method, the cage silsesquioxane resin (A), the unsaturated compound (B), the curing catalyst (C) and, if necessary, other compounds and solvents are mixed at room temperature ) To obtain a curable resin composition according to the present invention. Subsequently, the curable resin composition is dripped onto the glass fiber by a method such as dipping, and the solvent is removed if necessary. Next, the glass fiber impregnated with the curable resin composition is subjected to heat treatment and / or active energy ray irradiation treatment to cure the curable resin composition to obtain a glass fiber composite resin substrate of the present invention.

In the glass fiber composite resin substrate of the present invention, the mass ratio of the cured product of the curable resin composition per 1 m ² and the glass fiber (mass of the cured product: mass of the glass fiber) is preferably 20:80 to 70:30, : 60 to 60:40. When the ratio of the glass fibers to the cured product is less than the above lower limit, the heat resistance of the glass fiber composite resin substrate is lowered and the thermal expansion coefficient tends to exceed 20 ppm / K. On the other hand, Impregnation with the glass fiber composite resin substrate becomes insufficient, voids remain between the fibers, and the transparency of the glass fiber composite resin substrate tends to decrease (haze increase). Therefore, in the impregnation, it is preferable to impregnate the curable resin composition so that the ratio of the mass of the curable resin composition after curing to the mass of the glass fiber is within the above range.

In the above impregnation, it is possible to appropriately adjust the type of the glass fiber and the glass fiber composite resin substrate according to the purpose of use. For example, the thickness of the liquid crystal display or the organic EL display to which the glass fiber composite resin substrate is applied, It is preferable to impregnate the obtained glass fiber composite resin substrate so that the thickness of the obtained glass fiber composite resin substrate is 0.03 to 0.5 mm, preferably 0.05 to 0.2 mm.

The heating temperature in the heat treatment may be appropriately adjusted according to the curable resin composition, and is preferably from 50 to 200 캜, more preferably from 80 to 180 캜. If the heating temperature is lower than the lower limit described above, the progress of the curing reaction tends to be insufficient and a sufficient crosslinking structure tends not to be formed. On the other hand, if the heating temperature exceeds the upper limit, there is a tendency that the curable resin composition deteriorates or volatilizes before curing . The heating time in the above-mentioned heat treatment is preferably 30 to 60 minutes, although it can not be said at once because it depends on the heating temperature and the curable resin composition. The heat treatment is preferably carried out in an atmosphere of an inert gas such as nitrogen from the viewpoint of inhibiting the radical polymerization reaction of the curable resin composition by oxygen and tending to form a more satisfactory crosslinked structure .

As the conditions of irradiation with active energy rays in the above-described active energy ray irradiation treatment, ultraviolet rays having a wavelength of 10 to 400 nm and visible rays having a wavelength of 400 to 700 nm are preferably irradiated, and irradiation with near ultraviolet rays having a wavelength of 200 to 400 nm More preferable. The total exposure dose is preferably 2,000 to 10,000 mJ / cm ² . As the source of the active energy ray, a low-pressure mercury lamp (output: 0.4 to 4 W / cm), a high-pressure mercury lamp (40 to 160 W / cm) ), A pulsed xenon lamp (80 to 120 W / cm), and an electrodeless discharge lamp (80 to 120 W / cm).

The glass fiber composite resin substrate of the present invention may further comprise a coat layer made of resin on one surface or both surfaces of the glass fiber composite resin substrate for the purpose of smoothing the surface. It is preferable that the resin has heat resistance, transparency and chemical resistance, and it is particularly preferable to use the curable resin composition according to the present invention. The glass fiber composite resin substrate of the present invention may further comprise a gas barrier layer for oxygen or water vapor, if necessary.

<Examples>

Hereinafter, the present invention will be described more specifically based on examples and comparative examples, but the present invention is not limited to the following examples. In each of Preparation Examples, Examples and Comparative Examples, refractive index measurement, total light transmittance measurement, and heat resistance evaluation were performed by the following methods.

(Refractive index measurement)

The curable resin composition obtained in each of the preparation examples was cast (cast) to a thickness of 0.1 mm using a roll coater. Using a high-pressure mercury lamp of 80 W / cm ^2, an integrated exposure amount of 2000 mJ / cm ² To obtain a sheet-like cured product. The resulting cured product was measured for the refractive index at 589 nm using a refractive index meter (DR-M2, manufactured by Atago).

(Total light transmittance measurement)

The glass fiber composite resin substrate obtained in each of the Examples and Comparative Examples was measured for total light transmittance (%) using a haze meter (NDH2000, manufactured by Nippon Denshoku).

(Heat resistance evaluation)

· Glass transition temperature measurement, dynamic viscoelastic degradation rate measurement

Using a dynamic viscoelasticity measuring apparatus (trade name: DVE-V4, manufactured by Ubixo Company), the glass fiber composite resin substrate obtained in each of the examples and the comparative examples was measured at a temperature raising rate of 5 캜 / The dynamic viscoelasticity measurement was performed in the range of 30 to 300 占 폚, and the peak temperature of Tan? In the temperature range of 30 to 300 占 폚 was determined as the glass transition temperature (Tg (占 폚)). The dynamic viscoelasticity reduction rate (? E '(%))

ΔE '(%) = (E ' 30 -E '300) / E' 30

Wherein E _'30 denotes the dynamic viscoelasticity in the 30 ℃, E' ₃₀₀ shows the dynamic viscoelasticity of the 300 ℃.]

. The higher the glass transition temperature and / or the lower the dynamic viscoelasticity reduction ratio, the higher the heat resistance of the glass fiber composite resin substrate.

· Measurement of thermal expansion coefficient (linear thermal expansion coefficient)

Using a thermomechanical analyzer (TMA, trade name: TMA4000SA, manufactured by BRUKER), the glass fiber composite resin substrate obtained in each of the examples and the comparative examples was subjected to a heating rate of 5 占 폚 / min, a compression load of 0.1 N (X direction) of the glass fiber composite resin substrate (0.1 mm in thickness) at a temperature of 30 to 200 占 폚 under the conditions of the glass fiber composite resin substrate X direction) was calculated from the thermal expansion coefficient (ppm / K). The smaller the thermal expansion coefficient, the higher the heat resistance of the glass fiber composite resin substrate.

(Synthesis Example 1: Cage silsesquioxane resin (I))

The basket-like silsesquioxane resin (I) was prepared according to the method described in Japanese Patent Application Laid-Open No. 2004-143449. First, 40 ml of 2-propanol (IPA) as a solvent and 3.1 g of a 5% tetramethylammonium hydroxide aqueous solution (TMAH aqueous solution) as a basic catalyst were charged in a reaction vessel equipped with a stirrer, a dropping funnel and a thermometer. Further, 15 ml of IPA and 12.7 g of 3-methacryloxypropyltrimethoxysilane were charged in a dropping funnel to prepare an IPA solution of 3-methacryloxypropyltrimethoxysilane, and this was stirred in the reaction vessel at room temperature Followed by dropwise addition over 30 minutes. After completion of dropwise addition, the mixture was stirred for 2 hours without heating. After stirring, IPA was removed under reduced pressure to obtain 7.5 g of a composition containing the cage silsesquioxane resin (I). In the obtained composition, the cage-like silsesquioxane resin (I) according to the present invention is 97% by mass based on the total composition, and the cage silsesquioxane resin represented by the formula (3) 90% by mass with respect to the total amount of the silsesquioxane resin (I). As a result of mass spectrometry after separation by liquid chromatography, n in the formula (3) was 8, 10 and 12.

(Synthesis Example 2: cage-like silsesquioxane resin (II))

An IPA solution of 3-methacryloxypropyltrimethoxysilane and phenyltrimethoxysilane was prepared by charging 15 ml of IPA, 7.2 g of 3-methacryloxypropyltrimethoxysilane and 5.7 g of phenyltrimethoxysilane into a dropping funnel, And 8.7 g of a composition containing the cage silsesquioxane resin (II) was obtained in the same manner as in Synthesis Example 1, except that this was used in place of the IPA solution of 3-methacryloxypropyltrimethoxysilane. In the obtained composition, the cage-like silsesquioxane resin (II) according to the present invention is contained in an amount of 96% by mass based on the entire composition, and the cage silsesquioxane resin represented by the formula (3) (N + m) in the formula (3) was 8, 10, and 12 as a result of mass spectrometry after liquid chromatographic separation. The mass fraction of the silsesquioxane resin (II) was 92 mass% And n: m was 4: 4.

(Preparation Example 1: Curable resin composition (I))

, 60 parts by mass (in terms of cage-like silsesquioxane resin), 25 parts by mass of trimethylolpropane triacrylate, 15 parts by mass of dicyclopentanyl diacrylate: 15 parts by mass of the cage silsesquioxane resin (I) obtained in Synthesis Example 1, , And 2.5 parts by mass of 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator were mixed to obtain a liquid curable resin composition (I). The refractive index of this curable resin composition (I) was measured, and it was confirmed that the refractive index was 1.529, and a transparent cured product was obtained. The composition of the obtained curable resin composition (I) is shown in Table 1.

(Preparation Example 2: Curable resin composition (II)) [

30 parts by mass (in terms of cage-like silsesquioxane resin), 35 parts by mass of dicyclopentanyl diacrylate, 35 parts by mass of pentaerythritol tetraacrylate: 35 parts by mass And 2.5 parts by mass of 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator were mixed to obtain a liquid curable resin composition (II). The refractive index of this curable resin composition (II) was measured, and it was confirmed that the refractive index was 1.531, and a transparent cured product was obtained. The composition of the obtained curable resin composition (II) is shown in Table 1.

(Preparation Example 3: Curable resin composition (III)) [

10 parts by mass (in terms of cage-like silsesquioxane resin), 65 parts by mass of trimethylolpropane triacrylate, 35 parts by mass of dicyclopentanyl diacrylate, 35 parts by mass of the cage silsesquioxane resin (I) obtained in Synthesis Example 1, , And 2.5 parts by mass of 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator were mixed to obtain a liquid curable resin composition (III). The refractive index of this curable resin composition (III) was measured, and it was confirmed that the refractive index was 1.531, and a transparent cured product was obtained. The composition of the obtained curable resin composition (III) is shown in Table 1.

(Preparation Example 4: Curable resin composition (IV))

15 parts by mass (in terms of cage-like silsesquioxane resin), 50 parts by mass of trimethylolpropane triacrylate, 35 parts by mass of bisphenol fluorene diacrylate: 35 parts by mass of cage silsesquioxane resin (II) obtained in Synthesis Example 2, , And 2.5 parts by mass of 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator were mixed to obtain a liquid curable resin composition (IV). The refractive index of this curable resin composition (IV) was measured, and it was confirmed that the refractive index was 1.558, and a transparent cured product was obtained. The composition of the obtained curable resin composition (IV) is shown in Table 1.

(Preparation Example 5: Curable resin composition (V))

35 parts by mass (in terms of cage-like silsesquioxane resin), pentaerythritol tetraacrylate: 25 parts by mass, cage silsesquioxane resin (II) obtained in Synthesis Example 2, 40 parts by mass of bisphenol fluorene diacrylate And 2.5 parts by mass of 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator were mixed to obtain a liquid curable resin composition (V). The refractive index of this curable resin composition (V) was measured, and it was confirmed that the refractive index was 1.560, and a transparent cured product was obtained. The composition of the obtained curable resin composition (V) is shown in Table 1.

(Preparation Example 6: Curable resin composition (VI))

35 parts by weight of dicyclopentanyl diacrylate, 65 parts by weight of pentaerythritol tetraacrylate, and 2.5 parts by weight of 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator were mixed to obtain a liquid curable resin composition (VI) . The composition of the obtained curable resin composition (VI) is shown in Table 1.

(Preparation Example 7: Curable resin composition (VII))

, 25 parts by mass of pentaerythritol tetraacrylate, 40 parts by mass of bisphenol fluorene diacrylate, and 2.5 parts by mass of 1-hydroxycyclohexyl phenyl ketone as a photopolymerization initiator were mixed to obtain a liquid curable resin composition (VII) . The composition of the obtained curable resin composition (VII) is shown in Table 1.

(Preparation Example 8: Curable resin composition (VIII))

5 parts by mass of the cage silsesquioxane resin (I) obtained in Synthesis Example 1, 40 parts by mass of dicyclopentanyl diacrylate, 55 parts by mass of pentaerythritol tetraacrylate, and 1 part by mass of 1-hydroxycyclo And 2.5 parts by mass of hexyl phenyl ketone were mixed to obtain a liquid curable resin composition (VIII). The composition of the obtained curable resin composition (VIII) is shown in Table 1.

(Example 1)

First, the curable resin composition (I) obtained in Preparation Example 1 was added dropwise to a T glassy glass cloth (trade name: T glassy yarn (manufactured by Nitto Boseki), refractive index 1.530, thickness 96 m) provided on a glass plate, Was covered with a glass plate, the glass plate was sandwiched from the upper and lower surfaces thereof, and the curable resin composition was impregnated with glass cloth while applying a pressure. Subsequently, the cured resin composition was cured by irradiating ultraviolet rays (wavelength: 365 nm) at an integrated exposure dose of 2000 mJ / cm ² using a high-pressure mercury lamp of 80 W / cm while sandwiching the glass cloth impregnated on the glass plate. Subsequently, the resultant was heated at 250 DEG C for 10 minutes in a nitrogen atmosphere to obtain a glass fiber composite material having a mass ratio of the cured product of the curable resin composition per 1 m ^{2 of} thickness of 0.1 mm and the glass fiber (mass of the cured product: mass of the glass fiber) A resin substrate was obtained. The obtained glass fiber composite resin substrate was subjected to total light transmittance measurement and heat resistance evaluation, and the results are shown in Table 2.

(Example 2)

Except that the curable resin composition (II) obtained in Preparation Example 2 was used in place of the curable resin composition (I), the mass ratio of the cured product of the curable resin composition per 1 m ² and the glass fiber per 1 m ² (Mass of cured product: mass of glass fiber) of 48:52 was obtained. The obtained glass fiber composite resin substrate was subjected to total light transmittance measurement and heat resistance evaluation, and the results are shown in Table 2.

(Example 3)

Except that the curable resin composition (III) obtained in Preparation Example 3 was used in place of the curable resin composition (I), the mass ratio of the cured product of the curable resin composition per 1 m ² and the glass fiber per 1 m ² (Mass of the cured product: mass of the glass fiber) of 44:56 was obtained. The obtained glass fiber composite resin substrate was subjected to total light transmittance measurement and heat resistance evaluation, and the results are shown in Table 2.

(Example 4)

The curable resin composition (IV) obtained in Preparation Example 4 was used instead of the curable resin composition (I) to prepare an E glass type glass cloth (trade name: 2116 / AS887AW (manufactured by Asahi Kasei Imatori Co., (Mass of the cured product: mass of the glass fiber) of 0.1 mm in thickness and 1 m ^{2 of} the cured product of the curable resin composition and the glass fiber was obtained in the same manner as in Example 1 except that the refractive index was 1.558, Fiberglass composite resin substrate of 52:48. The obtained glass fiber composite resin substrate was subjected to total light transmittance measurement and heat resistance evaluation, and the results are shown in Table 2.

(Example 5)

Except that the curable resin composition (V) obtained in Preparation Example 5 was used in place of the curable resin composition (IV), the mass ratio of the cured product of the curable resin composition per 1 m ² and the glass fiber per 1 m ² (Mass of cured product: mass of glass fiber) of 48:52 was obtained. The obtained glass fiber composite resin substrate was subjected to total light transmittance measurement and heat resistance evaluation, and the results are shown in Table 2.

(Comparative Example 1)

Except that the curable resin composition (VI) obtained in Preparation Example 6 was used in place of the curable resin composition (I), the mass ratio of the cured product of the curable resin composition per 1 m ² and the glass fiber per 1 m ² (Mass of cured product: mass of glass fiber) of 47:53 was obtained. The obtained glass fiber composite resin substrate was subjected to total light transmittance measurement and heat resistance evaluation, and the results are shown in Table 2.

(Comparative Example 2)

Except that the curable resin composition (VII) obtained in Preparation Example 7 was used in place of the curable resin composition (I), the mass ratio of the cured product of the curable resin composition per 1 m ² and the glass fiber per 1 m ² (Mass of the cured product: mass of the glass fiber) was 49:51. The obtained glass fiber composite resin substrate was subjected to total light transmittance measurement and heat resistance evaluation, and the results are shown in Table 2.

(Comparative Example 3)

Except that the curable resin composition (VIII) obtained in Preparation Example 8 was used in place of the curable resin composition (I), the mass ratio of the cured product of the curable resin composition per 1 m ² and the glass fiber per 1 m ² (Mass of cured product: mass of glass fiber) of 47:53 was obtained. The obtained glass fiber composite resin substrate was subjected to total light transmittance measurement and heat resistance evaluation, and the results are shown in Table 2.

As apparent from the results shown in Table 2, all of the glass fiber composite resin substrates of the present invention have a total light transmittance of 90% or more, a sufficiently large glass transition temperature, and a dynamic viscoelasticity reduction ratio of 20% or less, It has been confirmed that it has a high level of heat resistance and transparency. It was also confirmed that the thermal expansion coefficient was 15 ppm / K or less and the thermal expansion coefficient was sufficiently small. On the other hand, in the conventional glass fiber composite resin substrates (Comparative Examples 1 and 2), it was confirmed that the total light transmittance was 90% or more, but the glass transition temperature was low and the dynamic viscoelasticity decreasing rate and the thermal expansion coefficient were also inferior.

INDUSTRIAL APPLICABILITY As described above, according to the present invention, it is possible to provide a glass fiber composite resin substrate having a high level of heat resistance and transparency and having a sufficiently small thermal expansion coefficient. Such a glass fiber composite resin substrate of the present invention has a high level of heat resistance that does not deteriorate the elastic modulus even at a high temperature. Therefore, it is very useful as a glass substitute substrate for use in, for example, flexible displays, touch panels, useful.

Claims (9)

A glass fiber composite resin substrate comprising a curable resin composition and glass fiber,
Wherein the curable resin composition comprises
(A) a basket-like silsesquioxane resin having at least one group selected from the group consisting of a (meth) acryloyl group, a glycidyl group and a vinyl group,
(B) the following general formulas (1) to (2):
-R ¹ -CR ² = CH ₂ - (One)
-CR ² = CH ₂ - (2)
[In the formula (1), R ¹ represents any one selected from the group consisting of an alkylene group, an alkylidene group and an -OCO- group. In the formulas (1) to (2), R ² independently represents a hydrogen atom or an alkyl group .]
An unsaturated compound other than the cage silsesquioxane resin having two or more unsaturated functional groups selected from the group consisting of
(C) Curing catalyst
, And the content of the cage-like silsesquioxane resin (A) in the curable resin composition is 5 to 90 mass% with respect to the total curable resin composition. The method according to claim 1,
Wherein the cage-like silsesquioxane resin (A) is represented by the following general formula (3):
_{^{[R 3 SiO 3/2]}} n [R 4 SiO 3/2] m ... (3)
(3), R ³ represents an organic group having a group selected from the group consisting of a (meth) acryloyl group, a glycidyl group and a vinyl group, R ⁴ represents a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, (I) to (iii): wherein R &lt; 1 &gt; represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms,
n? 1 ... (i)
m? 0 ... (ii)
n + m = h ... (iii)
[Wherein h in the formula (iii) represents an integer selected from the group consisting of 8, 10, 12 and 14]
, And when n and m are each 2 or more, R ³ and R ⁴ may be the same or different.
Is a basket-like silsesquioxane resin represented by the following formula (1). 3. The method of claim 2,
Wherein the ratio (n: m) of n to m in the general formula (3) is 10: 0 to 4: 6. The method according to claim 2 or 3,
Wherein the cage-like silsesquioxane resin represented by the general formula (3) is at least 50 mass% with respect to the total of the cage-like silsesquioxane resin (A). 5. The method according to any one of claims 1 to 4,
Wherein the unsaturated functional group of the unsaturated compound (B) is at least one group selected from the group consisting of an acryloyl group, a methacryloyl group, an allyl group and a vinyl group. 6. The method according to any one of claims 1 to 5,
Wherein the number of the unsaturated functional groups of the unsaturated compound (B) is 2 to 10 per one molecule of the compound. 7. The method according to any one of claims 1 to 6,
Wherein the curable resin composition is cured after impregnating the glass fiber with the curable resin composition. 8. The method of claim 7,
Wherein the mass ratio of the cured product of the curable resin composition and the glass fiber (mass of the cured product: mass of the glass fiber) is 20:80 to 70:30. 9. The method according to any one of claims 1 to 8,
Wherein the glass fiber composite resin substrate has a thickness of 0.03 to 0.5 mm.