JP2003260768A - Filler dispersion system resin sheet, liquid crystal cell substrate, and liquid crystal display unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a filler dispersion system resin sheet having a small linear expansion coefficient and free from warping or curling, a liquid crystal substrate using the filler dispersion system resin sheet, and a liquid crystal display unit comprises the liquid crystal substrate, and also to provide a substrate for an electroluminescence display and a substrate for a solar battery using the filler dispersion system resin sheet, and an electroluminescence display unit using the substrate for the electroluminescence display. <P>SOLUTION: The filler dispersion system resin sheet comprises at least an epoxy resin layer constituted of a filler-containing epoxy resin layer sandwiched between two filler-free epoxy resin layers. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a filler-dispersed resin sheet or a filler as described above, characterized in that a filler-containing epoxy resin layer has at least an epoxy resin layer sandwiched between two filler-free epoxy resin layers. The present invention relates to a liquid crystal cell substrate made of a dispersion resin sheet and a liquid crystal display device using the above liquid crystal cell substrate. The present invention also relates to a substrate for an electroluminescence display, a substrate for a solar cell, and an electroluminescence display device using the substrate for an electroluminescence display, each of which comprises the filler-dispersed resin sheet.

[0002]

2. Description of the Related Art With the increase in size of liquid crystal display devices and electroluminescence display devices, glass-based substrates are heavy and bulky, so resin sheets made of epoxy resin or the like are proposed as substrates for the purpose of thinning and weight reduction. Is being developed. However, since the resin sheet undergoes thermal expansion and expansion and contraction due to the inflow and outflow of water, there has been a problem in that the resin sheet is misaligned during electrode formation and color filter formation. Therefore, it has been studied to disperse an inorganic oxide having a particle size of less than 1 μm in a resin sheet to suppress the linear expansion coefficient, but the linear expansion coefficient is at most about 6.00E-5 / ° C., which is satisfactory. It wasn't a level. Further, in order to reduce the linear expansion coefficient, it has been studied to disperse large particles of about 1 to 100 μm in a resin sheet. For example, when the above particles are dispersed in an epoxy base material layer, in a epoxy base material coating liquid. As a result of the particles floating or settling, the particles are separated into a particle-containing side and a particle-free side, and the epoxy resin layer is divided into a portion having a large linear expansion coefficient and a portion having a small linear expansion coefficient, which warps the resin sheet and causes curling, resulting in workability. Is poor, and it is extremely difficult to manufacture a display device.

[0003]

DISCLOSURE OF THE INVENTION According to the present invention, a filler-dispersed resin sheet having a small linear expansion coefficient and no warpage or curl, a liquid crystal cell substrate using the filler-dispersed resin sheet, and the liquid crystal cell substrate are used. An object of the present invention is to provide a liquid crystal display device characterized by: Another object of the present invention is to provide a substrate for an electroluminescence display or a substrate for a solar cell which uses the filler-dispersed resin sheet, and an electroluminescence display device which uses the substrate for an electroluminescence display.

[0004]

DISCLOSURE OF THE INVENTION The present invention is a filler-dispersed resin sheet characterized in that the filler-containing epoxy resin layer has at least an epoxy resin layer sandwiched between two filler-free epoxy resin layers. Is provided. A hard coat layer or a gas barrier layer is preferably laminated on the filler-dispersed resin sheet. Further, the ratio (d1 / of the thickness (d1) of the filler-containing epoxy resin layer and the thickness (d2) of the filler-dispersed resin sheet)
d2) is preferably 0.15 or more, and the average particle diameter of the filler is preferably 1 to 100 μm, and 2
The linear expansion coefficient at 5 ° C to 160 ° C is 5.00E-5 /
The surface roughness of the outermost layer (R
It is preferable that a) is 2 nm or less. The present invention also provides a liquid crystal cell substrate made of the filler-dispersed resin sheet and a liquid crystal display device using the liquid crystal cell substrate. The present invention also provides a substrate for an electroluminescent display, which is made of the above-mentioned filler-dispersed resin sheet, and an electroluminescent display device using the substrate for an electroluminescent display. The present invention also provides a solar cell substrate comprising the above filler-dispersed resin sheet.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The filler-dispersed resin sheet according to the present invention is characterized by having at least an epoxy resin layer in which a filler-containing epoxy resin layer is sandwiched between two filler-free epoxy resin layers.

In the present invention, the filler-containing epoxy resin layer and the filler-free epoxy resin layer have different linear expansion coefficients, but the filler-containing epoxy resin layer is sandwiched between two filler-free epoxy resin layers. This makes it possible to prevent warping and curling.

In the present invention, when the thickness of the filler-containing epoxy resin layer is (d1) and the thickness of the filler-dispersed resin sheet, that is, the thickness of the entire sheet is (d2),
(D1 / d2) is 0.15 or more, preferably 0.5 or more, and more preferably 0.7 or more. (D1 / d2)
When the value is less than 0.15, the linear expansion coefficient of the filler-dispersed resin sheet becomes large, which causes a problem such as misalignment during electrode formation or color filter formation.

The thickness of the epoxy resin layer composed of the filler-containing epoxy resin layer and the two filler-free epoxy resin layers is preferably 100 to 800 μm. When the thickness of the epoxy resin layer is less than 100 μm, there is a problem in the strength of the display device, and when it is more than 800 μm, the characteristics of thinness and lightness are lost, and there is a problem in display quality.

In the present invention, it is necessary to use an epoxy resin in terms of surface smoothness and hue, and as the epoxy resin, for example, bisphenol A type, bisphenol F type, bisphenol S type and water addition thereof are used. Such as bisphenol type, phenol novolac type and cresol novolak type, novolak type, triglycidyl isocyanurate type and hydantoin type nitrogen-containing ring type, alicyclic type and aliphatic type, naphthalene type aromatic type and glycidyl type Examples include low water absorption type such as ether type and biphenyl type, dicyclo type, ester type and ether ester type, and modified forms thereof. These may be used alone or in combination. Among the various epoxy resins described above, it is preferable to use a bisphenol A type epoxy resin, an alicyclic epoxy resin, or a triglycidyl isocyanurate type from the viewpoint of discoloration preventing property and the like.

As such an epoxy resin, one having an epoxy equivalent of 100 to 1000 and a softening point of 120 ° C. or lower is generally preferably used from the viewpoint of physical properties such as flexibility and strength of the obtained resin sheet. Further, from the viewpoint of obtaining an epoxy resin-containing liquid having excellent coatability and spreadability into a sheet, etc., a two-liquid mixed type that exhibits a liquid state at a temperature below the coating temperature, particularly at room temperature, can be preferably used.

The epoxy resin is a curing agent, a curing accelerator, and if necessary, an antioxidant, a modifier, a surfactant, a dye, a pigment, a discoloration inhibitor, which has been conventionally used.
Various conventionally known additives such as an ultraviolet absorber can be appropriately blended.

The curing agent is not particularly limited, either.
One or two or more kinds of appropriate curing agents can be used according to the epoxy resin. Incidentally, examples thereof include organic acid compounds such as tetrahydrophthalic acid, methyltetrahydrophthalic acid, hexahydrophthalic acid and methylhexahydrophthalic acid, ethylenediamine and propylenediamine, diethylenetriamine and triethylenetetramine, and their amine adducts and metas. Examples include amine compounds such as phenylenediamine, diaminodiphenylmethane and diaminodiphenylsulfone.

Amide compounds such as dicyandiamide and polyamide, hydrazide compounds such as dihydrazide, methylimidazole, 2-ethyl-4-methylimidazole, ethylimidazole, isopropylimidazole, 2,4-dimethylimidazole, phenylimidazole, Imidazole compounds such as undecyl imidazole, heptadecyl imidazole, and 2-phenyl-4-methyl imidazole are also listed as examples of the curing agent.

Further, methyl imidazoline, 2-ethyl-4-methyl imidazoline, ethyl imidazoline, isopropyl imidazoline, 2,4-dimethyl imidazoline, phenyl imidazoline, undecyl imidazoline, heptadecyl imidazoline, 2-phenyl-4-methyl imidazoline Such imidazoline-based compounds, as well as phenol-based compounds, urea-based compounds, and polysulfide-based compounds are also mentioned as examples of the curing agent.

In addition, acid anhydride compounds and the like are also mentioned as examples of the above-mentioned curing agent, and such acid anhydride curing agent can be preferably used from the viewpoint of discoloration preventing property and the like. Examples include phthalic anhydride and maleic anhydride, trimellitic anhydride and pyromellitic anhydride, nadic acid anhydride and glutaric anhydride, tetrahydrophthalic anhydride and methyltetrahydrophthalic anhydride, and hexahydrophthalic anhydride. Examples thereof include methyl hexahydrophthalic anhydride, methyl nadic acid anhydride, dodecenyl succinic anhydride, dichlorosuccinic anhydride, benzophenone tetracarboxylic acid anhydride, and chlorendic acid anhydride.

Particularly, it is a colorless system or a pale yellow system such as phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride or methylhexahydrophthalic anhydride,
An acid anhydride-based curing agent having a molecular weight of about 140 to about 200 can be preferably used.

The mixing ratio of the epoxy resin and the curing agent is such that, when an acid anhydride curing agent is used as the curing agent, the acid anhydride equivalent is 0.5 to 1 to 1 equivalent of the epoxy group of the epoxy resin. It is preferable to add 5 equivalents, more preferably 0.7 to 1.2 equivalents. If the acid anhydride is less than 0.5 equivalent, the hue after curing becomes poor,
If it exceeds 1.5 equivalents, the moisture resistance tends to decrease. When other curing agents are used alone or in combination of two or more, the amount used can be in accordance with the above equivalent ratio.

Examples of the curing accelerator include tertiary amines, imidazoles, quaternary ammonium salts, organic metal salts, phosphorus compounds, urea compounds, and the like. Particularly, tertiary amines, It is preferable to use imidazoles. These can be used alone or in combination.

The amount of the curing accelerator compounded is preferably 0.05 to 7.0 parts by weight, more preferably 0.2 to 3.0 parts by weight, based on 100 parts by weight of the epoxy resin. . If the compounding amount of the curing accelerator is less than 0.05 parts by weight, a sufficient curing promoting effect cannot be obtained, and if it exceeds 7.0 parts by weight, the cured product may be discolored.

Examples of the antiaging agent include phenol compounds, amine compounds, organic sulfur compounds, phosphine compounds and the like, which are conventionally known.

Examples of the modifying agent include conventionally known ones such as glycols, silicones and alcohols.

The surface active agent is added to smooth the surface of the epoxy resin sheet when the epoxy resin sheet is formed by a casting method or the like while the epoxy resin is exposed to air. Examples of the surfactant include silicone-based, acrylic-based and fluorine-based surfactants, with the silicone-based surfactant being particularly preferred.

A hard coat layer or a gas barrier layer is preferably laminated on the filler-dispersed resin sheet of the present invention. In the present invention, the gas barrier layer may be inferior in scratch resistance and chemical resistance, so that it is preferable to stack the gas barrier layer between the layers instead of the outermost layer.

In the present invention, as the material for forming the hard coat layer, urethane resin, acrylic resin, polyester resin, polyvinyl alcohol, ethylene
Examples thereof include polyvinyl alcohol resins such as vinyl alcohol copolymers, vinyl chloride resins and vinylidene chloride resins.

Further, polyarylate resin, sulfone resin, amide resin, imide resin, polyether sulfone resin, polyetherimide resin, polycarbonate resin, silicone resin, fluorine resin, polyolefin resin, Styrene-based resin, vinylpyrrolidone-based resin, cellulose-based resin, acrylonitrile-based resin and the like can also be used for forming the resin layer. Among these resins, urethane resins are preferable, and urethane acrylate is particularly preferable. In addition, to form the resin layer,
It is also possible to use a blend of two or more kinds of appropriate resins.

As the material for the gas barrier layer in the present invention, polyvinyl alcohol and its partially saponified products, vinyl alcohol polymers such as ethylene / vinyl alcohol copolymers, and materials with small oxygen permeation such as polyacrylonitrile and polyvinylidene chloride are used. However, vinyl alcohol polymers are particularly preferable from the viewpoint of high gas barrier properties.

The thickness of the organic gas barrier layer is 2 to 10 μm.
m is preferable, and more preferably 3 to 5 μm. If the thickness of the organic gas barrier layer is less than 2 μm, a sufficient gas barrier function cannot be imparted, and if it exceeds 10 μm, the yellowness index (YI value) of the resin sheet increases.

An inorganic gas barrier layer may be laminated as the gas barrier layer in the present invention. Transparent gas barrier materials such as silicon oxide, magnesium oxide, aluminum oxide, and zinc oxide are known as materials for forming the inorganic gas barrier layer. However, due to their gas barrier properties and adhesion to the base material layer, etc. Silicon oxide is preferably used.

As the silicon oxide, the ratio of the number of oxygen atoms to the number of silicon atoms is 1.5 to 2.0. Gas barrier property, transparency, surface flatness, flexibility, film stress and cost of the inorganic gas barrier layer. Etc. are preferable. When the ratio of the number of oxygen atoms to the number of silicon atoms is smaller than 1.5, the flexibility and transparency deteriorate. In 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 material for forming the inorganic gas barrier layer, silicon nitride is also preferably used, and one having a ratio of the number of nitrogen atoms to the number of silicon atoms of 1.0 to 4/3 is preferably used.

The thickness of the inorganic gas barrier layer in the present invention is preferably 5 to 200 nm. When the thickness of the inorganic gas barrier layer is thinner than 5 nm, good gas barrier properties cannot be obtained, and when the thickness of the inorganic gas barrier layer is thicker than 200 nm, there are problems in transparency, flexibility, film stress and cost.

The filler in the present invention is soda glass,
Examples thereof include non-alkali glass, silica, titanium dioxide, antimony oxide, titania, alumina, zirconia, and tungsten oxide. These may be one kind or a mixture of two or more kinds. The average particle size of the filler is 1
It is preferably ˜100 μm. More preferably 5
˜80 μm is preferable, and more preferably 10 to 50 μm. If the particle size is less than 1 μm, the dispersibility is poor and the light transmittance is low, and if it exceeds 100 μm, the surface smoothness of the particle-dispersed resin sheet is poor.

The amount of the filler added in the present invention is preferably 10 to 70% by volume based on the volume of the base material layer.
More preferably, it is 20 to 65% by volume. When the addition amount of the inorganic oxide is less than 10% by volume with respect to the weight of the base material layer, the dimensional change of the particle-dispersed resin sheet is large and patterning of the color filter layer and electrode formation become difficult.
When it exceeds 70% by volume, the light transmittance and the surface smoothness of the particle-dispersed resin sheet are deteriorated.

The light transmittance of the particle-dispersed resin sheet according to the present invention is preferably 80% or more, more preferably 85% or more. If the light transmittance is less than 80%, the display when the liquid crystal display device is assembled using this particle-dispersed resin sheet becomes dark and the display quality is degraded.
The light transmittance is measured by using a spectrophotometer at λ = 550.
The transmittance in nm is measured.

2 of the particle-dispersed resin sheet in the present invention
The linear expansion coefficient at 5 ° C to 160 ° C is 5.00E-5 /
℃ or less, more preferably 3.0
It is preferably 0E-5 / ° C or lower. Linear expansion coefficient is 5.00E-5
If the temperature exceeds / ° C, patterning positional deviation easily occurs when the color filters are laminated. Further, it becomes difficult to form an electrode on the particle-dispersed resin sheet. The linear expansion coefficient can be measured by the TMA method described in JIS K-7197 and calculated by (Equation 1). In the above formula, ΔIs (T ₁ ) and ΔIs (T ₂ ) are TMA measurement values (μm) at temperatures T ₁ and T ₂ (° C.) at the time of sample measurement, and L ₀ is the length of the sample at room temperature. (M
m).

[Formula 1]

The outermost layer of the filler-dispersed resin sheet according to the present invention has a center line average roughness (Ra) according to JIS B0601 of 2 nm or less, more preferably 1 nm or less. When the center line average roughness (Ra) is larger than 2 nm, it becomes difficult to form an alignment film or an electrode. In the present invention, the hard coat layer and the epoxy resin layer are preferably the outermost layers from the viewpoint of good scratch resistance and chemical resistance.

In the filler-dispersed resin sheet of the present invention, the filler-containing epoxy resin layer has at least an epoxy resin layer sandwiched between two filler-free epoxy resin layers, and the hard coat layer and the gas barrier layer are Laminated, the ratio (d1 / d2) of the thickness (d1) of the filler-containing epoxy resin layer and the thickness (d2) of the filler-dispersed resin sheet is 0.15 or more, and the average particle diameter of the filler is 1 to 100 μm. Most preferably, the linear expansion coefficient at 25 ° C to 160 ° C is 5.00E-5 / ° C or less, and the surface roughness of the outermost layer is 2 nm or less.

The method for producing a filler-dispersed resin sheet of the present invention is as follows. A filler-free epoxy resin coating liquid is applied by sequential coating on a support having a hard coat layer formed thereon, followed by curing, and then a filler-containing resin. It can be formed by applying an epoxy resin coating liquid and then curing it, and finally applying a filler-free epoxy resin coating liquid and then curing it. Further, on the support on which the hard coat layer is formed, a filler-free epoxy resin coating liquid is applied and cured by sequential coating, and then a filler-containing epoxy resin coating liquid is applied to precipitate the filler. Apparently, the filler-containing epoxy resin layer and the filler-free epoxy resin layer may be simultaneously formed and cured. Alternatively, a gas barrier layer-forming resin liquid may be applied between the hard coat layer and the epoxy resin layer and then cured to form the gas barrier layer.

The filler-dispersed resin sheet of the present invention can be used for various purposes, and is also preferably used as a liquid crystal cell substrate, a substrate for electroluminescent displays, and a substrate for solar cells.

A liquid crystal display device is generally formed by appropriately assembling components such as a polarizing plate, a liquid crystal cell, a reflection plate or a backlight, and optical components as necessary, and incorporating a drive circuit. In the present invention, there is no particular limitation except that the above-mentioned resin sheet is used, and the resin sheet can be formed according to conventional methods. Therefore, when forming the liquid crystal display device in the present invention, for example, a light diffusion plate, an antiglare layer, an antireflection film, a protective layer, a protective plate provided on the polarizing plate on the viewing side, or between the liquid crystal cell and the polarizing plate on the viewing side. Appropriate optical components such as a retardation plate for compensation to be provided can be appropriately combined with the resin sheet.

In general, an electroluminescence display device comprises a transparent substrate, an organic light emitting layer and a metal electrode, which are sequentially laminated on a transparent substrate to form a light emitting body (organic electroluminescent light emitting body). Here, the organic light emitting layer is a laminate of various organic thin films, for example, a laminate of a hole injection layer made of a triphenylamine derivative or the like and a light emitting layer made of a fluorescent organic solid such as anthracene, Alternatively, a structure having various combinations such as a laminate of such a light emitting layer and an electron injection layer made of a perylene derivative, or a laminate of these hole injection layer, light emitting layer, and electron injection layer is known. Has been. In the organic electroluminescence device, by applying a voltage to the transparent electrode and the metal electrode, holes and electrons are injected into the organic light emitting layer, and the energy generated by the recombination of the holes and the electrons causes the fluorescent substance to flow. It emits light on the principle that it is excited and emits light when the excited fluorescent substance returns to the ground state. The mechanism of recombination in the middle is similar to that of a general diode, and as can be expected from this, the current and the emission intensity show a strong nonlinearity with rectification with respect to the applied voltage. In the organic electroluminescence device, at least one of the electrodes must be transparent in order to extract light emitted from the organic light emitting layer, and usually a transparent electrode formed of a transparent conductor such as indium tin oxide (ITO) is used. It is used as an anode. On the other hand, it is important to use a substance having a small work function for the cathode in order to facilitate electron injection and increase the luminous efficiency, and a metal electrode such as Mg-Ag or Al-Li is usually used. In the organic electroluminescence device having such a structure, the organic light emitting layer is formed of an extremely thin film having a thickness of about 10 nm. For this reason, the organic light emitting layer transmits light almost completely like the transparent electrode. as a result,
Light that enters from the surface of the transparent substrate when it is not emitting light, passes through the transparent electrode and the organic light emitting layer, and is reflected by the metal electrode goes out to the surface side of the transparent substrate again. The display surface of the sensing device looks like a mirror surface. In an organic EL device including an organic electroluminescent luminescent material having a transparent electrode on the front surface side of an organic light emitting layer that emits light by applying a voltage and a metal electrode on the back surface side of the organic light emitting layer, the front surface side of the transparent electrode It is possible to provide a polarizing plate at the same time and a phase plate between the transparent electrode and the polarizing plate. Since the phase plate and the polarizing plate have a function of polarizing light that is incident from the outside and reflected by the metal electrode, there is an effect that the mirror surface of the metal electrode is not visually recognized from the outside by the polarization action. Particularly, if the phase plate is composed of a quarter-wave plate and the angle formed by the polarization directions of the polarizing plate and the phase plate is adjusted to π / 4, the mirror surface of the metal electrode can be completely shielded. That is, as for the external light that enters the organic electroluminescence device, only the linearly polarized light component is transmitted by the polarizing plate. This linearly polarized light is generally elliptically polarized light by the phase plate, but it becomes circularly polarized light especially when the phase plate is a quarter-wave plate and the angle formed by the polarization directions of the polarizing plate and the phase plate is π / 4. This circularly polarized light passes through the transparent substrate, the transparent electrode, and the organic thin film, is reflected by the metal electrode, passes through the organic thin film, the transparent electrode, and the transparent substrate again, and becomes linearly polarized light again on the phase plate. Since this linearly polarized light is orthogonal to the polarization direction of the polarizing plate, it cannot pass through the polarizing plate. As a result, the mirror surface of the metal electrode can be completely shielded.

[0042]

The present invention will be described below with reference to examples.
The present invention is not limited to these examples.

Example 1: 100 parts by weight of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate represented by the chemical formula (formula 1) (hereinafter, the same), and represented by the chemical formula (formula 2) 125 parts of methylhexahydrophthalic anhydride, tetra-n-butylphosphonium o, o-diethylphosphorodithioate 1.25 parts represented by the chemical formula (Chemical Formula 3), glycerin 2.25 parts and silicone surfactant 0.07 part of the agent was mixed with stirring, and 340 parts of glass beads having an average particle diameter of 30 μm were mixed as a filler to prepare a filler-containing epoxy resin solution. A filler-free epoxy resin liquid was prepared in the same manner as above except that no filler was added.

[Chemical 1]

[Chemical 2]

[Chemical 3]

According to the manufacturing process illustrated in FIG. 1, a 17 wt% toluene solution of urethane acrylate represented by the chemical formula (Chemical formula 4) is first passed from the die 21 to the stainless endless belt 1 at a running speed of 0.3 m / min. Cast coating,
After air-drying to volatilize toluene, it was cured using a UV curing device to form a hard coat layer 10 having a film thickness of 2 μm. Subsequently, the filler-free epoxy resin liquid is cast and applied onto the hard coat layer from the die 22 at 0.3 m / min, and cured using a heating device to obtain a filler-free epoxy resin having a film thickness of 50 μm. Layer 11 was formed. Next, a filler-containing epoxy resin liquid is cast and applied from the die 23 at 0.3 m / min, and cured by using a heating device to give a film thickness of 300 μm.
A m-filler-containing epoxy resin layer 12 was formed. Next, a filler-free epoxy resin liquid is cast from a die 24 at 0.3 m / min and cured by using a heating device, and a filler-free epoxy resin layer 1 having a film thickness of 50 μm is formed.
Formed 3.

[Chemical 4]

Next, the laminate comprising the hard coat layer, the filler-free epoxy resin layer, the filler-containing epoxy resin layer, and the filler-free epoxy resin layer was peeled from the endless belt, and the oxygen concentration was changed to 0.5 by nitrogen substitution. % Atmosphere and left on a glass plate at 180 ° C. for 1 hour to perform after-cure.

Example 2 A filler-dispersed resin sheet was prepared in the same manner as in Example 1 except that the filler-containing epoxy resin layer had a thickness of 200 μm and the filler-free epoxy resin layer had a thickness of 100 μm.

Comparative Example 1 In the same manner as in Example 1, a filler-containing epoxy resin liquid and a filler-free epoxy resin liquid were prepared. Next, the filler-containing epoxy resin liquid was applied and cured on the stainless steel endless belt covered with the hard coat layer, and subsequently, the filler-free epoxy resin liquid was applied and cured. Next, the laminate comprising the hard coat layer, the filler-containing epoxy resin layer, and the filler-free epoxy resin layer was peeled off from the endless belt, and nitrogen substitution was carried out on a glass plate at 180 ° C. in an atmosphere having an oxygen concentration of 0.5%. After being left for 1 hour, after-cure was performed. In this case, the thickness of the filler-containing epoxy resin layer is 200μ
m, the thickness of the filler-free epoxy resin layer is 200 μm
Met.

Evaluation test: Light transmittance (%), linear expansion coefficient (/ ° C.), curl / warp light transmittance were measured by a high-speed spectrophotometer (Shimadzu MPS-200).
0) was used to measure the transmittance at λ = 550 nm. The linear expansion coefficient (/ ° C.) was calculated by measuring the TMA value (μm) at 25 ° C. and 160 ° C. using TMA / SS150C (manufactured by Seiko Instruments Inc.). Curl and warpage were visually evaluated according to the following criteria. ◯: When a square sample with a side of 10 cm was placed on the flat plate, the maximum distance between the flat plate and the sample was 2 mm or less. X: When a square sample having a side of 10 cm is placed on the flat plate, the maximum distance between the flat plate and the sample is larger than 2 mm.

The above results are shown in Table 1.

[Table 1]

The filler-dispersed resin sheets of Examples 1 and 2 have an epoxy resin layer in which a filler-containing layer is sandwiched between two filler-free layers, and both the linear expansion coefficient and the dimensional change rate are small, It showed high light transmittance. Further, a warp or curl was small, and a filler-dispersed resin sheet having good workability could be obtained. On the other hand, in the filler-dispersed resin sheet of Comparative Example 1, the epoxy resin layer was composed of two layers, a filler-containing layer and a filler-free layer, and both the linear expansion coefficient and the dimensional change rate were small, and high light transmittance was exhibited. Large warpage and curls were seen, and workability was poor.

[0051]

The filler-dispersed resin sheet of the present invention is
The coefficient of linear expansion is low, and there is no warpage or curl.
Therefore, the filler-dispersed resin sheet of the present invention has good workability and facilitates formation of electrodes, alignment films, and color filter layers.

[Brief description of drawings]

FIG. 1 One example of manufacturing process of filler-dispersed resin sheet

FIG. 2 is a filler-dispersed resin sheet of the present invention.

[Explanation of symbols]

1: Stainless steel endless belt 2: Drive drum 3: Driven drum 10: Hard coat layer 11: Filler-free epoxy resin layer 12: Filler-containing epoxy resin layer 13: Filler-free epoxy resin layer 21: Die for coating hard coat layer 22: Filler-free epoxy resin layer coating die 23: Filler-containing epoxy resin layer coating die 24: Filler-free epoxy resin layer coating die 31: UV curing device 32: Dryer 33: Dryer 34: Dryer

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H090 JB03 JD11 JD14 JD15 JD18                 4F100 AG00 AK53A AK53B AK53C                       BA03 BA05 BA07 BA10A                       BA10D BA25B CA23B CB00D                       DD07 DE01 DE01B GB41                       JA02 JD01E JL14 YY00B                 5C094 AA36 AA43 BA27 BA43 DA06                       DA12 EB10 FB01 FB16                 5F051 GA03 GA12

Claims (12)

[Claims] 1. A filler-dispersed resin sheet, wherein the filler-containing epoxy resin layer has at least an epoxy resin layer sandwiched between two filler-free epoxy resin layers. 2. A filler-dispersed resin sheet comprising the filler-dispersed resin sheet according to claim 1 and a hard coat layer laminated thereon. 3. A filler-dispersed resin sheet comprising the filler-dispersed resin sheet according to claim 1 and a gas barrier layer laminated thereon. 4. The thickness (d) of the filler-containing epoxy resin layer
The filler dispersion type resin sheet according to any one of claims 1 to 3, wherein the ratio (d1 / d2) of 1) to the thickness (d2) of the filler dispersion type resin sheet is 0.15 or more. 5. The filler-dispersed resin sheet according to claim 1, wherein the average particle diameter of the filler is 1 to 100 μm. 6. The filler-dispersed resin sheet according to claim 1, wherein the linear expansion coefficient at 25 ° C. to 160 ° C. is 5.00E-5 / ° C. or less. 7. The filler dispersed resin sheet according to claim 1, wherein the surface roughness (Ra) of the outermost layer is 2 nm or less. 8. A liquid crystal cell substrate comprising the filler-dispersed resin sheet according to claim 1. 9. A liquid crystal display device using the liquid crystal cell substrate according to claim 8. 10. A substrate for an electroluminescent display comprising the filler-dispersed resin sheet according to claim 1. 11. An electroluminescent display device using the substrate for electroluminescent display according to claim 10. 12. A solar cell substrate comprising the filler-dispersed resin sheet according to claim 1.