JP2006233129A - Resin sheet, liquid crystal cell substrate, substrate for electroluminescent display, substrate for solar battery and liquid crystal display device, electro luminescent display device and sollar battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin sheet being less prone to breaking and having excellent rigidity, by solving the problem wherein a conventional resin sheet of an epoxy-based resin and the like has good transparency and a strength sufficient for ordinary use, but is susceptible to breaking at the time of transporting and at the time when substrates made of the conventional resin are mounted in various display devices. <P>SOLUTION: The resin sheet has a base material layer comprising an epoxy resin material and acrylic-styrene copolymer particles with an average particle diameter of 0.1-2 μm. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a resin sheet, a liquid crystal cell substrate using the same, an electroluminescence (EL) display substrate or a solar cell substrate, and a liquid crystal display device, an electroluminescence display device or a solar cell using the same.

Conventionally, in a liquid crystal display device, a glass-based substrate has been used as a liquid crystal cell substrate for supporting a liquid crystal to form a liquid crystal cell in terms of transparency, strength, heat resistance, and the like.
However, in recent years, with the increase in size of liquid crystal display devices, it has been required to reduce the weight and thickness of the liquid crystal cell substrate. As an alternative to the glass substrate, a resin sheet made of an epoxy resin is used. Substrates have been proposed and put to practical use (for example, Patent Document 1 and Patent Document 2).
In addition, in EL display devices and the like, application of a substrate using the resin sheet as described above has been proposed due to the same problem.

  However, a resin sheet made of an epoxy resin or the like has transparency and strength enough to withstand use. For example, the resin sheet is transported and a substrate using the resin sheet is incorporated into various display devices. At times, there is a problem of being easily broken, and there is a demand for the development of a resin sheet that has excellent toughness and is difficult to break.

Japanese Patent No. 3197716 JP-A-11-333866

  In view of the above problems and demands, an object of the present invention is to provide a resin sheet that is excellent in toughness and hardly breaks.

  The inventors of the present invention, as a result of intensive studies to solve the above-mentioned demand, have obtained a resin sheet having a base material layer comprising an epoxy resin material and acrylic-styrene copolymer particles having a predetermined property. The present inventors have found that the above problems can be solved and have completed the present invention.

  That is, this invention provides the resin sheet characterized by having a base material layer containing an epoxy resin material and acrylic-styrene copolymer particles having an average particle diameter of 0.1 to 2 μm.

  The base material layer comprising the epoxy resin material and the acrylic-styrene copolymer particles having an average particle diameter of 0.1 to 2 μm includes the acrylic-styrene copolymer particles in the base material layer. It has excellent toughness and is difficult to break.

  Since the resin sheet of the present invention has a base material layer having excellent toughness, the resin sheet has excellent toughness and is difficult to break. Therefore, for example, the resin sheet can be prevented from cracking during transportation and when assembling various display devices.

Hereinafter, the resin sheet of the present invention will be described.
The resin sheet of the present invention has a base material layer comprising an epoxy resin material and acrylic-styrene copolymer particles having an average particle diameter of 0.1 to 2 μm.

The epoxy resin material used in the present invention is not particularly limited. For example, bisphenol A type, bisphenol F type and bisphenol types such as water additives thereof, novolak types such as phenol novolak type and cresol novolak type, triglycidyl isocyanate Nitrogen-containing ring type such as nurate type and hydantoin type, alicyclic type and aliphatic type, aromatic type such as naphthalene type, low water absorption type such as glycidyl ether type and biphenyl type, dicyclopentadiene type, ester type, An ether ester type or a modified version thereof can be used.
Among these, it is preferable to use an alicyclic epoxy resin material from the viewpoint of transparency.

  The alicyclic epoxy resin material is not particularly limited. For example, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 1,2-bis (hydroxylmethyl) -1-butanol, 2-epoxy-4- (2-oxiranyl) cyclohexane adducts and the like. Among these, since it is excellent in the fluidity of the coating liquid and the heat resistance after curing, 3,4-epoxycyclohexylmethyl- 3,4-epoxycyclohexanecarboxylate is preferred.

  As said dicyclopentadiene type epoxy resin, what is shown by following formula (1) is preferable.

前記式（１）において、Ｒ１，Ｒ２及びＲ３は、水素又は直鎖若しくは分岐鎖を有するアルキル基であって、それぞれ同一であっても異なっていてもよく、ｎは重合度を示す。
前記アルキル基の炭素数は、１〜９の範囲が好ましい。Ｒ１，Ｒ２及びＲ３は、水素が好ましい。また、重合度ｎは、特に制限されないが、例えば、０〜１０の範囲であり、好ましくは０〜６の範囲であり、特に好ましくは、０〜４の範囲である。尚、Ｒ１，Ｒ２及びＲ３やｎが異なるジシクロペンジエン型エポキシ樹脂の混合物であってもよい。

In the formula (1), R1, R2 and R3 are hydrogen or a linear or branched alkyl group, which may be the same or different, and n represents the degree of polymerization.
The alkyl group preferably has 1 to 9 carbon atoms. R1, R2 and R3 are preferably hydrogen. The degree of polymerization n is not particularly limited, but is, for example, in the range of 0 to 10, preferably in the range of 0 to 6, and particularly preferably in the range of 0 to 4. In addition, the mixture of the dicyclopendiene type | mold epoxy resin from which R1, R2, and R3 and n differ may be sufficient.

For example, various additives may be blended in the epoxy resin material as necessary.
Examples of the additive include conventionally known additives such as a curing agent, a curing accelerator, an anti-aging agent, a modifier, a surfactant, a dye, a pigment, a discoloration inhibitor, and an ultraviolet absorber.
Any one of these additives may be used, or two or more of them may be used.

  Although it does not restrict | limit especially as said hardening | curing agent, The suitable hardening | curing agent according to the said epoxy resin material may be used. Examples of the curing agent include organic acid compounds such as tetrahydrophthalic acid, methyltetrahydrophthalic acid, hexahydrophthalic acid, and methylhexahydrophthalic acid, ethylenediamine, propylenediamine, diethylenetriamine, triethylenetetramine, metaphenylenediamine, Examples include amine compounds such as diaminodiphenylmethane and diaminodiphenylsulfone. Any one kind of these curing agents may be used, or two or more kinds thereof may be used.

  In addition to the curing agent as described above, for example, amide compounds such as dicyandiamide and polyamide, hydrazide compounds such as dihydrazide, methylimidazole, 2-ethyl-4-methylimidazole, ethylimidazole, isopropylimidazole, Imidazole compounds such as 2,4-dimethylimidazole, phenylimidazole, undecylimidazole, heptadecylimidazole, 2-phenyl-4-methylimidazole, methylimidazoline, 2-ethyl-4-methylimidazoline, ethylimidazoline, isopropylimidazoline Imidazoline compounds such as 2,4-dimethylimidazoline, phenylimidazoline, undecylimidazoline, heptadecylimidazoline, 2-phenyl-4-methylimidazoline, Examples thereof include nool compounds, urea compounds, polysulfide compounds, and the like.

Furthermore, acid anhydride compounds and the like can also be used as the curing agent. An acid anhydride compound is preferable because it can prevent discoloration of the base material layer. Examples of the acid anhydride compounds include phthalic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic anhydride, nadic acid anhydride, glutaric anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexa Hydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl nadic anhydride, dodecenyl succinic anhydride, dichloro succinic anhydride, benzophenone tetracarboxylic anhydride, chlorendic anhydride, methyl nadic anhydride Etc.
Among these acid anhydride compounds, in particular, colorless or light yellow type such as phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl nadic acid anhydride, etc. And those having a molecular weight of about 140 to 200 are preferably used.

The mixing ratio of the epoxy resin material and the curing agent is not particularly limited. For example, when an acid anhydride compound is used as the curing agent, the acid anhydride compound 0. 5-1.5 equivalent is preferable, More preferably, it is 0.7-1.2 equivalent.
If the blending amount of the acid anhydride compound is less than 0.5 equivalent, the hue after curing is deteriorated, and if it exceeds 1.5 equivalent, sufficient moisture resistance cannot be maintained.
In addition, also when another hardening | curing agent is used or when one type or two or more types of hardening agents are used together, it can mix | blend according to the above equivalent ratios.

The curing accelerator is not particularly limited, and examples thereof include tertiary amines, imidazoles, quaternary ammonium salts, organometallic salts, phosphorus compounds, urea compounds, and the like.
Among these, phosphorus compounds are particularly preferable. These curing accelerators may be, for example, one type, or two or more types may be used in combination.

  The mixing ratio of the curing accelerator is not particularly limited, and can be appropriately determined according to the amount and type of the epoxy resin material. Specifically, the curing accelerator is preferably 0.05 to 7.0 parts by weight, more preferably 0.2 to 3.0 parts by weight with respect to 100 parts by weight of the epoxy resin material. If the blending amount of the curing accelerator is less than 0.05 parts by weight, a sufficient curing accelerating effect cannot be obtained, and if it exceeds 7.0 parts by weight, the cured product may be discolored.

  Although it does not restrict | limit especially as said anti-aging agent, For example, conventionally well-known things, such as a phenol type compound, an amine type compound, an organic sulfur type compound, a phosphine type compound, can be used.

  Although it does not restrict | limit especially as said modifier | denaturant, For example, conventionally well-known things, such as glycols, silicones, alcohol, can be used.

  The surfactant is added to make the surface of the base material layer smooth when the base material layer is formed by curing the epoxy resin material in contact with air. As the surfactant, for example, various surfactants such as silicone-based, acrylic-based and fluorine-based surfactants can be used, and among these, silicone-based surfactants are preferable.

The acrylic-styrene copolymer particles used in the present invention have an average particle size of 0.1 to 2 μm. The acrylic-styrene copolymer particles are excellent in both toughness and transparency as long as the average particle size is in the range of 0.1 to 2 μm.
In the acrylic-styrene copolymer particles used in the present invention, the proportion of styrene in the copolymer is usually 2 to 50% by weight, preferably 5 to 30% by weight.
The average particle size is measured by the method described in the examples.

The acrylic-styrene copolymer particles generally have a refractive index of 1.48 to 1.54. The refractive index difference between the cured product of the epoxy resin material and the acrylic-styrene copolymer particles is within 0.01, preferably within 0.005.
When the refractive index difference is out of the range of 0.01 or less, the transparency of the obtained base material layer is lowered, and as a result, the transparency of the resin sheet is also lowered.
Here, the cured product of the epoxy resin material refers to a cured product of the epoxy resin material itself that does not include acrylic-styrene copolymer particles.
The refractive index is measured by the method described in the examples.

The base material layer is formed by blending 2 to 50 parts by weight, preferably 10 to 40 parts by weight of the acrylic-styrene copolymer particles with respect to 100 parts by weight of the epoxy resin material. When the blending amount of the acrylic-styrene copolymer particles is less than 2 parts by weight, the effect of imparting toughness to the resin sheet may not be obtained.
Further, when the blending amount of the acrylic-styrene copolymer particles exceeds 50 parts by weight, the viscosity increases when the epoxy resin material and the acrylic-styrene copolymer particles are mixed, and the epoxy resin material contains In addition, the acrylic-styrene copolymer particles may be difficult to uniformly disperse.

The base material layer has a glass transition temperature (Tg) of 170 ° C. or higher, preferably 190 ° C. or higher. The upper limit of the glass transition temperature (Tg) is not limited.
When the glass transition temperature of the base material layer is 170 ° C. or higher, the heat resistance becomes high, and the quality can be kept stable in the process of assembling a liquid crystal display device or the like.
The glass transition temperature is measured by the method described in the examples.

  The thickness of the base material layer is not particularly limited and can be appropriately determined according to the use. From the viewpoint of rigidity, flexibility, thinness and lightness, for example, the thickness is 50 μm or more, preferably in the range of 100 to 800 μm. More preferably, it is the range of 100-400 micrometers. Moreover, when using for optical uses, such as a liquid crystal cell substrate, it is preferable that it is the range of 100-200 micrometers, for example.

A hard coat layer and a gas barrier layer may be laminated on the resin sheet of the present invention.
The hard coat layer and the gas barrier layer may be directly laminated on the base material layer in the resin sheet, or may be laminated via another member.
When the hard coat layer is laminated as the outermost layer of the resin sheet, the scratch resistance and the like of the resin sheet are improved.
Also, in various image display devices such as liquid crystal display devices, when moisture or oxygen penetrates the liquid crystal cell and enters the liquid crystal cell, the liquid crystal is altered or bubbles are formed, thereby causing poor appearance or disconnection of the conductive film pattern. Etc. may occur. However, by providing the gas barrier layer, for example, gas such as moisture and oxygen can be prevented from passing therethrough.

When the resin sheet of the present invention includes both the hard coat layer and the gas barrier layer, the stacking order is not particularly limited. For example, it is preferable that the base sheet layer, the gas barrier layer, and the hard coat layer are stacked in this order. .
In particular, since the hard coat layer is excellent in impact resistance, chemical resistance, etc., it is preferably laminated as the outermost layer, and the hard coat layer may be laminated on the other surface of the base material layer. .

  Examples of the material for forming the hard coat layer include urethane resins, acrylic resins, and polyester resins. Also, for example, polyarylate resin, sulfone resin, amide resin, imide resin, polyethersulfone resin, polyetherimide resin, polycarbonate resin, silicone resin, fluorine resin, polyolefin resin, styrene Resin, vinyl pyrrolidone resin, cellulose resin, acrylonitrile resin and the like can also be used. Among these, urethane resin is preferable, and urethane acrylate is more preferable. These resins may be one kind or a blend resin in which two or more kinds are mixed.

  The thickness of the hard coat layer is not particularly limited, but is usually in the range of 1 to 10 μm, preferably in the range of 1.5 to 8 μm, and more preferably in the range of 2 to 5 μm.

  Examples of the gas barrier layer include an organic gas barrier layer and an inorganic gas barrier layer. As the material for forming the organic gas barrier layer, for example, polyvinyl alcohol and partially saponified products thereof, vinyl alcohol polymers such as ethylene / vinyl alcohol copolymer, and materials having low oxygen transmission such as polyacrylonitrile and polyvinylidene chloride are used. Among these, vinyl alcohol polymers are particularly preferable from the viewpoint of high gas barrier properties.

  The thickness of the organic gas barrier layer is preferably 15 μm or less from the viewpoints of, for example, transparency, coloring prevention, functionality such as gas barrier properties, thinness, and flexibility of the resulting resin sheet. Preferably it is 13 micrometers or less, More preferably, it is 2-10 micrometers, Most preferably, it is the range of 3-5 micrometers. If the thickness is 15 μm or less, a lower yellowness index (YI value) can be maintained in the resin sheet, and if it is 2 μm or more, a sufficient gas barrier function is maintained.

  On the other hand, as a material for forming the inorganic gas barrier layer, for example, transparent materials such as silicon oxide, silicon nitride, magnesium oxide, aluminum oxide, and zinc oxide can be used. Silicon oxide and silicon nitride are preferable because of excellent adhesion to the layer.

  As said silicon oxide, it is preferable that the ratio of the number of oxygen atoms with respect to the number of silicon atoms is 1.5-2.0, for example. This is because, at such a ratio, for example, the inorganic gas barrier layer is further excellent in terms of gas barrier properties, transparency, surface flatness, flexibility, film stress, cost, and the like. In the silicon oxide, the maximum value of the ratio of the number of oxygen atoms to the number of silicon atoms is 2.0.

  As the silicon nitride, for example, the ratio of the number of nitrogen atoms to the number of silicon atoms is preferably 1.0 to 4/3.

  The thickness of the inorganic gas barrier layer is not particularly limited, but is preferably in the range of 5 to 200 nm, for example. If the thickness is 5 nm or more, further excellent gas barrier properties can be obtained, and if the thickness is 200 nm or less, the transparency, flexibility, film stress, and cost are also excellent.

The resin sheet of the present invention has a light transmittance of, for example, 88% or more, preferably 89% or more. If the light transmittance is 88% or more, the display when an image display device such as a liquid crystal display device is assembled using this resin sheet becomes sufficiently bright, and the display quality is further improved.
The light transmittance is measured by the method described in the examples.

Next, the manufacturing method of the resin sheet of this invention is demonstrated.
First, a predetermined amount of epoxy resin material and a predetermined amount of acrylic-styrene copolymer particles having an average particle diameter of 0.1 to 2 μm are mixed to prepare a uniform coating solution. In mixing, a conventionally known appropriate solvent may be used. At this time, various additives may be appropriately added to the coating solution as described above.
And the base material layer is formed by applying the said coating liquid on suitable board | substrates, such as stainless steel, and making it harden | cure.

  For the coating of the coating liquid, for example, a roll coating method, a spin coating method, a wire bar coating method, a dip coating method, an extrusion method, a curtain coating method, a spray coating method, or the like is used.

At the time of the curing, for example, a curing treatment such as a heat treatment or a light irradiation treatment is performed on the coated coating liquid as necessary. The curing conditions for the coating liquid are not particularly limited. For example, in the case of heat treatment, it is preferable to cure at a curing temperature of 150 to 200 ° C. for about 20 minutes to 3 hours.
The curing temperature may be raised stepwise, for example, it may be cured at 120 ° C. for 1 hour, and then cured at 180 ° C. for 0.5 hour.

Moreover, when laminating | stacking a hard-coat layer directly on the said base material layer, a hard-coat layer should just be formed on suitable board | substrates, such as stainless steel, for example, and a base material layer may be formed on it.
That is, a hard coat layer is formed by applying a coating liquid for forming a hard coat layer on the substrate by using a method such as a roll coat method and curing it. Next, on the hard coat layer, a uniform coating liquid obtained by mixing the epoxy resin material and the acrylic-styrene copolymer particles is applied on the hard coat layer by the above-described coating method and dried. Good. Moreover, you may perform hardening processes, such as heat processing and a light irradiation process, as needed.
In addition, when mixing an epoxy resin material and acrylic-styrene copolymer particle | grains, you may use a suitable solvent.

  Further, when a gas barrier layer is included, for example, the hard coat layer is formed on a substrate, the gas barrier layer is formed thereon, and then the base material layer is further formed. The method for forming the gas barrier layer is not particularly limited, and for example, a conventionally known method is appropriately employed.

  The resin sheet of this invention can be used for various uses, for example, can be used as a liquid crystal cell substrate, an electroluminescence display substrate, or a solar cell substrate. When used as various substrates in this way, for example, it may be used in the same manner as a conventionally used transparent substrate such as a glass substrate.

  The liquid crystal cell substrate of the present invention can be used for a liquid crystal display device, the substrate for an electroluminescence display device of the present invention can be used for an electroluminescence display device, and the substrate for a solar cell of the present invention can be used for a solar cell. These various substrates can be used, for example, as substitutes for glass substrates and the like used in various conventional display devices and solar cells. If such various substrates of the present invention are used, various display devices having transparency, sufficient strength and toughness, and reduced in thickness and weight can be realized.

A liquid crystal display device generally includes a liquid crystal cell in which liquid crystal is held on a liquid crystal cell substrate having electrodes, a polarizing plate, a reflector, and a backlight, and is configured by incorporating a drive circuit and the like. In the liquid crystal display device of the present invention, the resin sheet of the present invention may be used as a liquid crystal cell substrate. Except for this point, there is no particular limitation, and various conventionally known components may be provided.
Therefore, in the liquid crystal display device of the present invention, for example, a light diffusing plate, an antiglare layer, an antireflection film, a protective layer, a protective plate provided on the polarizing plate on the viewing side, or You may combine optical components, such as a phase difference plate for compensation provided between a liquid crystal cell, the polarization | polarized-light on the visual recognition side, and a board.

  In general, an electroluminescent display device is formed by sequentially laminating a transparent electrode, an organic light emitting layer including a light emitter (organic electroluminescent light emitter), and a metal electrode on a transparent substrate (electroluminescent display substrate). Is made up of. In the electroluminescent display device of the present invention, the resin sheet of the present invention is only required to be used as an electroluminescent display substrate. Except for this point, there is no particular limitation. For example, conventionally known various configurations Parts may be provided.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. Various characteristics were measured by the following methods.

(Measurement of average particle size)
An epoxy resin material and acrylic-styrene copolymer particles are mixed and cured to prepare a test piece. The obtained test piece is cut and its cross section is observed with an electron microscope. The acrylic-styrene copolymer The diameter (longest diameter) of 20 particle cross sections was measured, and the average was taken as the average particle diameter of the present invention.

(Measurement method of refractive index)
The measurement was performed at a wavelength of 589 nm using an Atago Abbe type measuring instrument (DR-M2 / 1550).

(Measurement method of light transmittance)
The light transmittance was determined by measuring the transmittance at λ = 550 nm using a high-speed spectral transmittance measuring device (Murakami Color Research Laboratory: DOT-3).

(Measurement method of glass transition temperature)
The glass transition temperature was measured using a dynamic viscoelastic device (ARES manufactured by Rheometrics), and the peak value of tan δ was defined as Tg (glass transition temperature).

(Measurement method of breaking strength)
The breaking strength (toughness) was obtained by cutting the resin sheets obtained in Examples and Comparative Examples into a length of 100 mm and a width of 10 mm using a razor blade (blade width of 100 μm), at the center in the longitudinal direction of the resin sheet. A test piece having one notch having a depth of 300 μm crossed along the width direction was prepared, and the diameter of the cylinder at which the test piece was broken was obtained by winding the test piece around the cylinder.
Note that the smaller the diameter of the cylinder at break, the stronger the toughness.

Example 1
3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (26.6 parts by weight) represented by the following formula (2), acrylic-styrene copolymer particles having an average particle diameter of 0.3 μm (refractive index: 1) .50) (10 parts by weight), methylhexahydrophthalic anhydride (33.1 parts by weight) represented by the following formula (3), tetra-n-butylphosphonium-O, O represented by the following formula (4) -Diethyl phosphorodithioate (1.5 parts by weight) was mixed, and the acrylic-styrene copolymer particles were uniformly dispersed using a high speed disper to obtain a coating solution. The refractive index of the cured product of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate was 1.505.
Next, a 17% by weight toluene solution of urethane acrylate represented by the following formula (5) is cast on a stainless steel endless belt with a running speed of 0.5 m / min using a die, and air-dried to volatilize toluene. Then, it was cured using a low-pressure ultraviolet curing device to form a hard coat layer having a thickness of 2.0 μm.
Subsequently, the coating solution is cast-applied at a rate of 0.3 m / min from the die onto the hard coat layer, cured using a heating device (heating temperature 180 ° C., heating time 0.5 hr), and a film thickness of 150 μm. A base material layer was formed.

(Example 2)
Dicyclopentadiene type epoxy resin represented by the formula (1) (n = 2, R1 to R3 are all hydrogen) (22 parts by weight), 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (78 parts by weight), acrylic-styrene copolymer particles having an average particle size of 0.3 μm (refractive index 1.51) (40 parts by weight), methyl nadic anhydride (110 parts by weight), tetra-n-butylphosphonium A resin sheet was prepared in the same manner as in Example 1 except that -O, O-diethyl phosphorodithioate (2 parts by weight) was used. The thickness of the resin sheet was 100 μm.
The refractive index of the cured product of a mixture of dicyclopentadiene type epoxy resin and 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate was 1.512.

(Example 3)
Bisphenol A type epoxy resin (epoxy equivalent 190) (19 parts by weight), acrylic-styrene copolymer particles having an average particle size of 0.3 μm (refractive index 1.50) (6 parts by weight), methylhexahydrophthalic anhydride A resin sheet was prepared in the same manner as in Example 1 except that (16.8 parts by weight) and tetra-n-butylphosphonium-O, O-diethyl phosphorodithioate (1.5 parts by weight) were used. The thickness of the resin sheet was 170 μm.
The refractive index of the cured bisphenol A type epoxy resin was 1.54.

(Comparative Example 1)
A resin sheet was prepared in the same manner as in Example 1 except that acrylic-styrene copolymer particles having an average particle diameter of 3 μm were used. The thickness of the resin sheet was 150 μm.

(Comparative Example 2)
A resin sheet was prepared in the same manner as in Example 1 except that the acrylic-styrene copolymer particles were not added. The thickness of the resin sheet was 150 μm.

The resin sheet obtained in Example 1 and Comparative Example 2 was used as a test piece, and the breaking strength was measured using the method for measuring the breaking strength.
The results are shown in Table 1.

  It was found that the break strength was improved in Examples 1 to 3 using acrylic-styrene copolymer particles having an average particle size of 0.3 μm.

Claims (14)

  A resin sheet comprising a base material layer comprising an epoxy resin material and acrylic-styrene copolymer particles having an average particle diameter of 0.1 to 2 µm.   The resin sheet according to claim 1, wherein the epoxy resin material is an alicyclic epoxy resin material.   3. The resin sheet according to claim 1, wherein the base material layer contains 2 to 50 parts by weight of the acrylic-styrene copolymer particles with respect to 100 parts by weight of the epoxy resin material.   The resin sheet according to any one of claims 1 to 3, wherein the base material layer has a glass transition temperature (Tg) of 170 ° C or higher.   The resin sheet according to any one of claims 1 to 4, wherein a difference in refractive index between the cured product of the epoxy resin material and the acrylic-styrene copolymer particles is within 0.01.   The resin sheet as described in any one of Claims 1-5 by which the hard-coat layer is laminated | stacked.   The resin sheet according to any one of claims 1 to 6, wherein a gas barrier layer is laminated.   The resin sheet according to any one of claims 1 to 7, wherein the light transmittance is 88% or more.   A liquid crystal cell substrate comprising the resin sheet according to claim 1.   A liquid crystal display device comprising the liquid crystal cell substrate according to claim 9.   The board | substrate for electroluminescent display apparatuses containing the resin sheet as described in any one of Claims 1-8.   An electroluminescent display device comprising the substrate for an electroluminescent display device according to claim 11.   The board | substrate for solar cells containing the resin sheet as described in any one of Claims 1-8.   A solar cell comprising the solar cell substrate according to claim 13.