JP4171134B2 - Continuous production method of epoxy resin sheet - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a continuous production method having excellent optical properties and excellent mass productivity of an epoxy resin sheet suitable for a liquid crystal cell substrate and the like.
[0002]
BACKGROUND OF THE INVENTION
Conventionally, when a method of applying a resin coating solution directly on a casting support such as an endless belt or a roll to form a sheet is applied to an epoxy resin coating solution to form a cured sheet, the curing is performed. There is a problem that the sheet adheres strongly to the support, and when it is peeled and recovered, there is a problem that damage such as cracks and residual distortion occurs in the cured sheet, and it is particularly difficult to obtain an optical sheet having a thickness of 500 μm or less. Met.
[0003]
[Technical Problem of the Invention]
An object of the present invention is to develop a continuous production method capable of efficiently obtaining an epoxy resin sheet having excellent optical characteristics even when the thickness is 500 μm or less.
[0004]
[Means for solving problems]
In the present invention, a hard coat resin coating liquid is spread on a support in the form of a sheet, the spread layer is cured to form a hard coat layer, and the hard coat layer is formed directly or separately on the hard coat layer. The coating liquid of thermosetting epoxy resin is spread in a sheet form through the film, and the spread layer is heat-cured to form a cured sheet that adheres directly to the hard coat layer or through a separate superimposed layer And providing a continuous process for producing an epoxy resin sheet, wherein the cured sheet is cooled to a temperature 10 to 80 ° C. lower than the thermosetting temperature and peeled and recovered from the support together with the hard coat layer. To do.
[0005]
【The invention's effect】
According to the present invention, the stress generated between the resin sheet and the support based on the difference in linear expansion coefficient between the resin sheet and the support acts favorably on the release of the resin sheet from the support, and the cured sheet of epoxy resin. It can be easily peeled off from the support together with the hard coat layer that adheres well to it, and can be recovered smoothly while preventing the occurrence of cracks and residual strain, etc., even when the thickness is 500 μm or less An epoxy resin sheet that is excellent in optical properties and heat resistance, and that favorably reflects the surface state such as mirror surface and unevenness in the support can be obtained efficiently and continuously through a simple operation.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
In the production method according to the present invention, a hard coat resin coating liquid is spread on a support in the form of a sheet, the spread layer is cured to form a hard coat layer, and directly or separately on the hard coat layer. The thermosetting epoxy resin coating solution is spread in a sheet form through the superimposed layer of the resin, and the spread layer is cured by thermosetting and adhered to the hard coat layer directly or through a separate superimposed layer. A sheet is formed, the cured sheet is cooled to a temperature lower by 10 to 80 ° C. than the thermosetting temperature, and peeled and recovered from the support together with the hard coat layer to obtain an epoxy resin sheet continuously. .
[0007]
The method according to the present invention uses at least a hard coat resin coating solution and a thermosetting epoxy resin coating solution, for example, a roll coating method, a wire bar coating method, an extrusion coating method, a curtain coating method, a spray coating method. An appropriate method such as a coating method or a doctor blade method, which can be formed into a sheet shape by fluid development of an epoxy resin coating liquid or the like, can be applied. In particular, the casting method, particularly the extrusion coating method in which the epoxy resin coating solution is fluidly developed through a die, can be preferably applied from the viewpoint of coating efficiency and production efficiency.
[0008]
FIG. 1 shows a process example of a continuous production method by the extrusion coating method. In this method, first, a support body composed of an endless belt 4 is rotated at a constant speed of 0.1 to 50 m / min, in particular 0.2 to 5 m / min in the direction of an arrow through a drive drum 5 and a driven drum 6. Then, the coating liquid of the hard coat resin is continuously applied in a sheet form through the die 11 and the development layer 12 is dried or cured by heating or light irradiation as necessary from the film. Hard coat layer 1 is obtained. In the illustrated example, an ultraviolet irradiation device 13 is disposed.
[0009]
Next, a die 31 is formed on the hard coat layer while sequentially forming the hard coat layer 1 on the support as described above, or on the overlapping layer 2 provided separately according to the hard coat layer as necessary. Then, a coating solution of a thermosetting epoxy resin is sequentially applied and spread in a sheet shape, and the spread layer 32 is heat-cured through an appropriate heating type curing device 33, and the hard coat layer 1 described above. The cured sheet 3 that is in close contact with each other is sequentially formed, and the cured sheet 3 is cooled to a temperature that is 10 to 80 ° C. lower than the thermosetting temperature and recovered from the support 4 together with the hard coat layer 1 and the like. The target epoxy resin sheet is continuously produced.
[0010]
According to the above method, the epoxy resin sheet can be continuously produced through a simple series of operations, and is excellent in mass productivity. The hard coat layer 1 to be formed first on the support 4 is obtained as the obtained epoxy. This makes it possible to easily and efficiently peel and collect the resin sheet from the support. The mass production speed can be easily controlled by adjusting the moving speed of the spreading layer via the support, and the thickness of the epoxy resin sheet obtained by adjusting the moving speed and the coating liquid spreading quantity can also be easily controlled. .
[0011]
In the above, as the support, an epoxy resin coating liquid such as a belt-like material such as an endless belt, a plate-like material, or a drum can be successively and continuously developed, and the development layer can be supported and maintained in a sheet shape as appropriate. Anything can be used. The material for forming the support may be any material as long as it can withstand the thermosetting treatment of the epoxy resin, and may be an appropriate material such as a metal such as stainless steel, copper, or aluminum, glass, or plastic. In particular, stainless steel is preferable from the viewpoint of durability.
[0012]
Moreover, according to the said method, the surface form of a support body can be favorably transferred and reflected through the said hard-coat layer. Therefore, the surface of the support can be made into an appropriate form such as a smooth surface or an uneven surface such as a fine prism shape or a fine lens shape according to the surface form of the epoxy resin sheet to be formed. In general, it is possible to obtain an epoxy resin sheet having a smooth surface and a mirror surface using a support having a surface roughness Ra of 0.02 μm or less.
[0013]
The hard coat layer that is initially provided on the support is intended to coat the surface of the resulting epoxy resin sheet to make it less likely to be scratched. However, a hard coat resin which has a weak adhesive force and can be easily peeled off from the support is preferably used.
[0014]
There is no limitation in particular about the kind of above-mentioned hard coat resin, A suitable thing can be used. Examples include urethane resins, acrylic resins, polyester resins, polyvinyl alcohol, polyvinyl alcohol resins such as ethylene vinyl alcohol copolymers, vinyl chloride resins, vinylidene chloride resins, polyarylate resins and sulfones. Resin, amide resin, imide resin, polyethersulfone resin, polyetherimide resin, polycarbonate resin, silicone resin, fluorine resin, polyolefin resin, styrene resin, vinylpyrrolidone resin, cellulose Examples thereof include resins and acrylonitrile resins. For forming the hard coat layer, a suitable blend of two or more hard coat resins may be used.
[0015]
The hard coat layer is excellent in optical properties such as transparency in optical applications by being in close contact with the epoxy cured sheet and being peeled and recovered from the support together to form a one-side surface layer of the epoxy resin sheet. It is preferable. From the viewpoints of such optical properties and easy peelability, particularly easy peelability to a stainless steel support, those that can be preferably used for forming the hard coat layer are urethane resins.
[0016]
The hard coat layer is formed by, for example, dissolving the hard coat resin in an appropriate solvent such as an organic solvent or water as required, and applying the solution on the predetermined surface of the support by the appropriate method as described above, and applying it as necessary. After drying, the film can be formed into a film by an appropriate method such as a method of curing treatment by a method according to a resin such as heat treatment or light irradiation. The viscosity of the coating solution can be determined as appropriate, but is generally 1 to 100 cP from the viewpoint of coating efficiency. In addition, an appropriate transparent additive such as a linear saturated hydrocarbon can be blended in the coating liquid of the hard coat resin for the purpose of improving the peelability from the support.
[0017]
The thickness of the hard coat layer to be formed can be determined as appropriate, but is generally 1 to 10 μm, especially 8 μm or less, particularly 2 to 2 μm from the viewpoint of easy peelability and prevention of cracking during peeling. The thickness is preferably 5 μm. In the case where a coating layer of urethane resin or the like is cured by light irradiation, it is preferable from the viewpoint of processing efficiency to use a high-pressure or low-pressure ultraviolet lamp having a center wavelength of 365 nm or 254 nm.
[0018]
When forming an epoxy resin sheet as shown by temporary wire in FIG. 1, a separate overlapping layer 2 may be provided on the hard coat layer 1 as necessary, and a cured sheet 3 of epoxy resin may be provided thereon. it can. In the illustrated example, in accordance with the formation of the hard coat layer described above, the coating liquid for superimposition is sequentially spread on the hard coat layer via the die 21 and the spread layer 22 is formed into a film via the curing device 23. The overlapping layer 2 is formed. The overlapping layer provided as necessary between the hard coat layer 1 and the cured sheet 3 of epoxy resin has chemical resistance, optical anisotropy, low water absorption, low moisture permeability, low oxygen permeability and the like. It may be for the purpose of imparting appropriate functions such as gas barrier properties. Therefore, the overlapping layer provided separately may be one layer or two or more layers.
[0019]
Incidentally, in a liquid crystal cell, if moisture or oxygen permeates the cell substrate and enters the cell, there is a risk of deterioration of the liquid crystal, appearance failure due to bubble formation, disconnection of the transparent conductive film pattern, or the like. Therefore, in the case of a liquid crystal cell, it is important to prevent the permeation of water vapor and oxygen gas, and a cell substrate provided with a gas barrier layer capable of preventing the permeation of these gases is preferably used.
[0020]
The coating liquid for forming the gas barrier layer can be prepared using an appropriate material that can be liquefied and can prevent permeation of the target gas. In general, it has excellent permeation-preventing ability of target gases such as water vapor and oxygen gas, and in particular, has a small oxygen permeability coefficient such as polyvinyl alcohol and its partially saponified products, ethylene / vinyl alcohol copolymer, polyacrylonitrile, and polyvinylidene chloride. Polymers such as are used. In particular, vinyl alcohol polymers can be preferably used from the viewpoints of gas barrier properties, moisture diffusivity, and uniformity of water absorption.
[0021]
The coating liquid for forming a superimposed layer such as a gas barrier layer provided on the hard coat layer can be fluidly developed like a polymer solution, for example, using one or two or more forming materials in combination with a solvent as necessary. It can be prepared by making it into a state. The thickness of the overlapping layer such as a gas barrier layer to be formed can be determined as appropriate and is not particularly limited. In general, the thickness should be 15 μm or less, especially 13 μm or less, especially 1 to 10 μm, from the viewpoints of transparency, coloring prevention, functionality such as gas barrier properties, thinness, and flexibility of the resulting epoxy resin sheet. preferable.
[0022]
For the preparation of the epoxy resin coating liquid developed on the hard coat layer or the overlying layer thereon, one or two thermosetting epoxy resins appropriate for the purpose of use of the epoxy resin sheet or the like More than one species can be used, and there is no particular limitation on the type.
[0023]
Incidentally, examples of the thermosetting epoxy resin include bisphenol types such as bisphenol A type, bisphenol F type, bisphenol S type and hydrogenated types thereof, novolak types such as phenol novolak type and cresol novolak type, and triglycidyl isocyanate. Nitrogen-containing ring type such as nurate type and hydantoin type, alicyclic type, aliphatic type, aromatic type such as naphthalene type, low water absorption type such as glycidyl ether type, biphenyl type, dicyclo type, ester type and ether ester Molds, modified versions thereof, and the like.
[0024]
Epoxy resins that are less likely to cause curing discoloration and can be preferably used from the viewpoint of optical properties such as transparency include bisphenol A type, alicyclic type, and triglycidyl isocyanurate type. In addition, an epoxy resin that can be preferably used from the viewpoint of physical properties such as rigidity and strength of a resin sheet when used as a cell substrate or the like forms a cured resin having an epoxy equivalent of 100 to 1000 and a softening point of 120 ° C. or less. It is.
[0025]
Furthermore, from the point of obtaining an epoxy-based resin coating solution that is excellent in coating property and developability to a sheet shape, etc., a two-component mixed type that shows a liquid state at a temperature below the coating temperature, in particular, at room temperature. It can be preferably used. In that case, a solid epoxy resin can be used in combination for the purpose of improving viscosity, improving strength, heat resistance, and the like.
[0026]
On the other hand, a curing agent is usually blended in the epoxy resin coating liquid. The curing agent to be used is not particularly limited, and one or more suitable curing agents according to the combined thermosetting epoxy resin can be used. Incidentally, examples thereof include organic acid compounds such as tetrahydrophthalic acid, methyltetrahydrophthalic acid, hexahydrophthalic acid and methylhexahydrophthalic acid.
[0027]
Also, ethylenediamine, propylenediamine, diethylenetriamine, triethylenetetramine, their amine adducts, metaphenylenediamine, amine compounds such as diaminodiphenylmethane and diaminodiphenylsulfone, amide compounds such as dicyandiamide and polyamide, and hydrazide compounds such as dihydragit. Are also examples of the curing agent.
[0028]
Further imidazole compounds such as methylimidazole, 2-ethyl-4-methylimidazole, ethylimidazole, isopropylimidazole, 2,4-dimethylimidazole, phenylimidazole, undecylimidazole, heptadecylimidazole, 2-phenyl-4-methylimidazole. Are also examples of the curing agent.
[0029]
Furthermore, imidazolines such as 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. Other examples of the curing agent include compounds, other phenolic compounds, urea compounds, and polysulfide compounds.
[0030]
In addition, acid anhydride compounds and the like are also examples of the curing agent. From the point of high temperature durability, discoloration prevention, etc. due to improved work environment due to low irritation and heat resistance improvement of the resulting epoxy resin sheet. Such an acid anhydride curing agent can be preferably used. Examples include phthalic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic anhydride, nadic anhydride, glutaric anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, and methylhexahydroanhydride. Examples thereof include phthalic acid, methyl nadic anhydride, dodecenyl succinic anhydride, dichlorosuccinic anhydride, benzophenone tetracarboxylic anhydride, and chlorendic anhydride.
[0031]
In particular, in view of the above-mentioned discoloration prevention property, it is colorless or pale yellow like phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride or methylhexahydrophthalic anhydride, and has a molecular weight of about 140 to about 200. An acid anhydride curing agent can be preferably used.
[0032]
The amount of the curing agent used can be determined as appropriate according to the type of the curing agent and the epoxy equivalent of the epoxy resin, and can be based on the usual epoxy resin curing. Generally, 0.5 to 1.5 equivalents, especially 0.6 to 1.4 equivalents, especially 0 to 1.4 equivalents with respect to 1 equivalent of the epoxy group from the viewpoint of preventing the hue and moisture resistance of the resulting epoxy resin sheet from decreasing. It is preferable to use a curing agent in a ratio of 7 to 1.2 equivalents.
[0033]
In preparing the epoxy resin coating liquid, appropriate additives such as a curing accelerator and a leveling agent can be blended as necessary. The curing accelerator is blended for the purpose of shortening the necessary curing treatment time by promoting the curing rate, and the blending can shorten the required length of the support to about a fraction of that in the case of not blending. Accordingly, it is preferable to add a curing accelerator from the viewpoint of improving mass productivity and reducing the size of a continuous production facility.
[0034]
There is no particular limitation on the curing accelerator to be used, and for example, tertiary amines, imidazoles, quaternary ammonium salts, organometallic salts, phosphorus compounds, urea based on the type of epoxy resin or curing agent. One or more suitable compounds such as compounds can be used. The amount of the curing accelerator used can be appropriately determined according to the accelerating effect and the like, but generally 0.05 to 7 parts by weight per 100 parts by weight of the epoxy resin from the viewpoint of discoloration prevention, etc. 1 to 5 parts by weight, particularly 0.2 to 3 parts by weight is preferred.
[0035]
On the other hand, the leveling agent prevents the surface of the epoxy resin coating liquid from becoming a satin-like surface due to variations in surface tension due to scattering of the curing agent, etc., when it is cured in contact with air. For the purpose of forming a smooth and smooth surface, for example, one or two types of suitable ones that can reduce the surface tension of various surfactants such as silicone, acrylic and fluorine The above can be used.
[0036]
In addition, for example, phenol-based, amine-based, organic sulfur-based, phosphine-based anti-aging agents, glycols, silicones, alcohols and other modifiers, anti-foaming agents and hydroxyl group-containing compounds, dyes and discoloration inhibitors, UV absorption Additives such as agents can also be blended. The antifoaming agent is added for the purpose of preventing air bubbles that cause a decrease in optical properties from being mixed into the resulting epoxy resin sheet, and polyhydric alcohols such as glycerin can be preferably used.
[0037]
The epoxy resin coating liquid can be prepared by bringing the blending components into a state that can be fluidly developed by using a solvent together as necessary. The viscosity of the coating solution can be determined as appropriate, but is generally 100 poises or more, particularly 120 to 500 poises, particularly 150 to 150 poises from the viewpoints of improvement in thickness accuracy by suppressing thickness unevenness and coating efficiency. The viscosity is preferably 300 poise. In addition, it is preferable to maintain the support body which supports the expansion | deployment layer of an epoxy resin coating liquid as horizontal as possible from points, such as suppression of thickness nonuniformity.
[0038]
The curing process of the development layer of the epoxy resin coating liquid is performed by a curing method by heating. Thereby, the cured sheet excellent in heat resistance can be obtained. As the heating means, one or more appropriate means such as hot air or an infrared heater can be used. The heating temperature is preferably 250 ° C. or lower, more preferably 220 ° C. or lower, and particularly preferably 120 to 180 ° C. from the viewpoint of the heat resistance and optical characteristics of the resulting cured sheet.
[0039]
The heating time is generally 5 to 60 minutes, especially 10 to 40 minutes, particularly 15 to 30 minutes, but is not limited thereto. In general, a relatively short heating time such as 15 to 30 minutes is preferable from the viewpoint of improving optical characteristics. From the viewpoint of improving the thickness accuracy, it is preferable to prevent the temperature variation in the width direction of the development layer as much as possible.
[0040]
The thickness of the epoxy resin sheet can be appropriately determined according to the purpose of use of the cell substrate and the like. In general, the thickness is 1 mm or less, especially 100 to 800 μm, especially 200 to 500 μm, from the viewpoints of rigidity such as bending strength, flexibility, surface smoothness, low phase difference and thin and light weight. In the case of optical applications, the thickness accuracy is preferably ± 20% or less, more preferably ± 15% or less, and particularly preferably ± 10% or less.
[0041]
In the continuous production method according to the present invention, the separation and recovery of the formed epoxy resin sheet from the support is 10 to 80 than the processing temperature when the development layer of the epoxy resin coating liquid is heated to form a cured sheet. Cool to a lower temperature. Thereby, it can peel smoothly from a support body, preventing generation | occurrence | production of a crack and a residual distortion. This is because a stress that is advantageous for peeling based on the difference in linear expansion coefficient is generated at the interface between the epoxy resin sheet and the support due to cooling.
[0042]
When the temperature difference from the thermosetting temperature by cooling at the time of peeling described above is less than 10 ° C, permanent deformation such as plastic deformation and residual strain is likely to occur, and when it exceeds 80 ° C, cracks and cracks are likely to occur. . The temperature is preferably 15 to 75 ° C., and more preferably 20 to 70 ° C., lower than the points such as balanced flexibility capable of preventing the occurrence of permanent deformation and cracking, and the generation of stress advantageous for peeling by cooling. It is.
[0043]
Although the cooling treatment is performed on the peeling portion from the support of the epoxy resin sheet or in the vicinity thereof as shown in the figure, the cooling means is not particularly limited and an appropriate method can be adopted. As an example, there are a system using a cooling roll 7 as shown by a temporary wire in the figure, and a system 8 in which a liquid coolant such as a cooling gas or ethyl cellosolve is sprayed. A rapid cooling system that cools the cured sheet as quickly as possible is preferable from the viewpoint of shortening the production line.
[0044]
In collecting the epoxy resin sheet from the above support, a peeling means can be used as necessary. By the way, after forming the hard coat layer or the overlapping layer as necessary, heat-resistant tape is adhered to the edges, etc., and a cured sheet of epoxy resin is formed on it. Thus, the epoxy resin sheet can be efficiently peeled and recovered from the support.
[0045]
The formed epoxy resin sheet continuum can be recovered by cutting to an appropriate size via an appropriate cutting means such as a laser beam, an ultrasonic cutter, dicing, or a water jet, if necessary.
[0046]
The epoxy resin sheet according to the present invention can be preferably used for a cell substrate in various cells such as a liquid crystal cell. Especially for cell substrates for optical applications, such as liquid crystal cell substrates that are required to have excellent heat resistance, optical properties, surface smoothness, etc., withstand high-temperature processing, excellent bending strength, small phase difference, and excellent lightness. It can be preferably used.
[0047]
The liquid crystal cell substrate is an epoxy resin sheet having a glass transition temperature of 120 ° C. or higher, particularly 130 ° C. or higher, particularly 140 ° C. or higher, because it can withstand a high temperature atmosphere in the manufacturing process of the liquid crystal cell. preferable. The glass transition temperature can be measured in a tensile mode by TMA (thermomechanical analysis method) under conditions of a heating rate of 2 ° C./min.
[0048]
When forming a liquid crystal cell using the epoxy resin sheet according to the present invention, various functional layers such as a transparent conductive film, an alignment film, a polarizing plate and a retardation plate can be superposed as necessary in accordance with conventional methods. The liquid crystal cell to be formed is arbitrary, such as a TN type, STN type, TFT type, or ferroelectric liquid crystal type.
[0049]
【Example】
Example 1
3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate 100 parts (parts by weight, the same applies hereinafter), methylhexahydrophthalic anhydride 125 parts, tetra-n-butylphosphonium o, o-diethyl phosphorodithio 3.75 parts of ate, 2.25 parts of glycerin and 0.07 part of a silicone-based surfactant (leveling agent, manufactured by Enomoto Kasei Co., Ltd., Disparon LS-009) are mixed with stirring and aged at 49 ° C. for 90 minutes to heat. A curable epoxy resin coating solution was prepared.
[0050]
Next, a 17 wt% toluene solution of urethane-based ultraviolet curable resin (manufactured by Shin-Nakamura Chemical Co., Ltd., NK Oligo UN-01) is discharged from the die by the casting method illustrated in FIG. It is cast on a stainless steel endless belt that rotates at a constant speed. After toluene is evaporated and dried, it is cured through an ultraviolet irradiation device (center wavelength 254 nm, integrated light quantity 2000 mJ / cm ² ), width 500 mm, thickness 2 μm. A hard coat layer was formed.
[0051]
Next, while continuing the above operation, the above epoxy resin coating solution was continuously discharged from the die at a rate of 100 g / min onto the hard coat layer which was hardened and cast and developed into a sheet shape. After a thermosetting treatment at 140 ° C. for 25 minutes through a heating device to obtain a cured sheet, a cooling roll 7 having a temperature controlled at 80 ° C. disposed on the upper surface of the sheet as shown in the figure on a driven drum temperature-controlled at 130 ° C. The peeled portion is rapidly cooled, and the cured sheet is peeled and collected from the endless belt together with the hard coat layer adhered thereto, and is cut at intervals of 490 mm in the flow direction to have a width of 450 mm, an average thickness of 400 μm, and a thickness accuracy of ± An epoxy resin sheet having a smooth surface and excellent optical property uniformity of 50 μm or less was continuously obtained.
[0052]
Example 2
Instead of the cooling roll, the air knife 8 disposed on the lower side of the sheet is blown with air at 30 ° C. to the peeling portion, and rapidly cooled while controlling the spraying amount so that the temperature of the peeling portion does not become 60 ° C. or less. An epoxy resin sheet was continuously obtained in the same manner as in Example 1 except for the above.
[0053]
Example 3
The development layer of the epoxy resin coating solution developed on the hard coat layer is thermally cured at 120 ° C. for 25 minutes to obtain a cured sheet, and then on the driven drum adjusted to 110 ° C. under the sheet as shown in the figure. The surface is smooth with a width of 450 mm, an average thickness of 400 μm, and a thickness accuracy of ± 50 μm or less in the same manner as in Example 1 except that 100 ° C. ethyl cellosolve was sprayed onto the peeled portion from the outlet 8 arranged on the side. An epoxy resin sheet having excellent optical property uniformity was obtained continuously.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a manufacturing process example.
1: Hard coat layer 2: Overlapping layer (gas barrier layer)
3: Heat-cured sheet of epoxy resin 11, 21, 31: Die 12, 22, 32: Expanded layer 13, 23, 33: Curing device 4: Support (endless belt)
7: Cooling roll 8: Blowing device for cooling gas or liquid coolant

Claims (3)

A hard coat resin coating solution is spread on a support in the form of a sheet, the spread layer is cured to form a hard coat layer, and heat is applied directly on the hard coat layer or via a separate superimposed layer. A coating liquid of a curable epoxy resin is spread in a sheet shape, and the spread layer is heat-cured to form a cured sheet that is in close contact with the hard coat layer directly or via a separate superimposed layer, and then cured. A continuous production method of an epoxy resin sheet, wherein the sheet is cooled to a temperature lower by 10 to 80 ° C. than the thermosetting temperature, and peeled and collected together with the hard coat layer from the support. The continuous production method of an epoxy resin sheet according to claim 1, wherein a gas barrier layer is formed on the hard coat layer, and a cured sheet of the epoxy resin is formed thereon at a heat curing temperature of 120 to 180 ° C. 3. The method for continuously producing an epoxy resin sheet according to claim 1 or 2, wherein the cured sheet is cooled using a cooling roll, a cooling gas, or a liquid coolant.

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