JP2001290157A - Resin sheet, its manufacturing method and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin sheet comprising a thermoplastic or thermosetting resin which, used as substrates of a liquid crystal cell, makes a cell gap uniform and makes excellent display quality without color irregularity or the like obtainable, to provide its manufacturing method and to provide a liquid crystal display device using the sheet. SOLUTION: The substrate is composed of the resin sheet comprising the thermoplastic or thermosetting resin. Spacers used to control the distance between the two substrates placed opposite to each other via a liquid crystal layer are integrated with the substrates without using any adhesive substance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid crystal display device in which a substrate is made of a thermoplastic or thermosetting resin, in order to control a cell gap, a spacer is provided on the substrate to make the cell gap uniform. The present invention relates to a resin sheet, a method for manufacturing the same, and a liquid crystal display device using the resin sheet.

[0002]

2. Description of the Related Art In recent years, liquid crystal display devices have been used for various purposes, but their manufacture is made through various materials and numerous manufacturing steps. Reduction and high accuracy are important issues. Above all, the liquid crystal cell, which is the center of the liquid crystal display device, is a collection of fine technologies, and the distance between two electrode substrates, the so-called cell gap, is the response speed, contrast,
It is a characteristic factor that greatly affects display quality such as visual characteristics and display unevenness, and control of the cell gap is an extremely important issue in manufacturing a liquid crystal cell. In the case of using a substrate made of a thermoplastic or thermosetting resin in a liquid crystal display device, the cell gap adjustment is usually performed in the same manner as a conventional glass substrate.
A spacer for adjusting the cell gap of about μm is scattered on one substrate, and the other substrate is bonded via a sealant. However, since a substrate made of a plastic material is more flexible and less rigid than glass, the cell gap is likely to fluctuate due to the substrate being bent or deformed, and it is difficult to fix the spacer.

[0003] As a result, there have been problems in that the spacers move to cause color unevenness (cell gap unevenness), and when the spacers move, the alignment film is damaged, causing display unevenness.

In order to solve such a problem, there has been proposed a method of bonding and fixing a spacer on a substrate. As a specific method, a method of fixing in an alignment film, a method of fixing in an insulating film, a method of fixing using a thermoplastic resin, a method of fixing using a thermosetting resin, and the like have already been proposed. However, among them, a spacer is coated with a thermoplastic resin, and after dispersing and dispersing the spacer, the spacer is heated by using a hot air or an IR furnace as disclosed in JP-A-6-95127. A method of bonding and fixing the spacer to the substrate is generally used.

However, when the spacers are coated with a thermoplastic resin and dispersed and dispersed, and the spacers are adhered and fixed to the substrate, the spacer surfaces are adhered to each other to form a block, so that it is difficult to uniformly disperse the spacers. However, there is a problem that the toner tends to be uneven.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a resin which has a uniform cell gap in a liquid crystal cell using a sheet made of a thermoplastic or thermosetting resin as a substrate and which can provide good display quality without color unevenness. Sheet and its manufacturing method,
And to provide a liquid crystal display device using the resin sheet.

[0007]

According to the present invention, a substrate is made of a thermoplastic or thermosetting resin, and a spacer used for controlling a distance between two substrates disposed opposite to each other with a liquid crystal layer interposed therebetween has an adhesive property. An object of the present invention is to provide a resin sheet integrated with a substrate without using a substance, a method of manufacturing the same, and a liquid crystal display device using the resin sheet.

In this case, before the thermoplastic or thermosetting resin is cured, a spacer is sprayed on the resin layer, and then the resin is cured to integrate the spacer with the substrate. At this time, the lower portion of each spacer is covered with the resin, and the spacer is fixed by the adhesive force of the resin.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The substrate according to the present invention is disposed opposite to a liquid crystal display device via a liquid crystal layer, and is made of a thermoplastic or thermosetting resin. In the resin sheet of the present invention, the spacer used for controlling the substrate interval on the substrate is integrated with the substrate without using an adhesive substance. The shape of the spacer is substantially spherical before being integrated, and after being integrated with the substrate, a part of the spacer is coated with resin and becomes substantially hemispherical. The density of the spacer is 10 pieces / mm ^{2 to} 1000
Is preferably 0 / mm ^2, more preferably it is 50 / mm ² to 1500 pieces / mm ^2. If the spacer density is less than 10 / mm ^2, it is difficult to control the cell gap, and the spacer density is 1 / mm ^2.
If it is larger than 0000 / mm ^{2, the} spacers will be in a lump and the cell gap accuracy will be poor. Further, since the ratio of the spacer to the liquid crystal in the liquid crystal cell is increased, the display quality is reduced.

In the method for continuously producing a resin sheet according to the present invention, a thermoplastic or thermosetting resin layer (B) is spread on a support coated with an easily peelable resin layer (A) by a casting method. Before the resin layer (B) is cured, for example, in a semi-cured state, after the spacers are sprayed, the resin layer (B) is cured, and the resin layer (A) is peeled off from the support to form an adhesive substance. Thus, a resin sheet integrated with the substrate can be obtained without using the resin sheet. In the present invention, since no sticky substance is used to fix the spacer, there is no need to cover the spacer with a thermoplastic or thermosetting resin or to coat the substrate surface with the resin.
In the semi-cured state, the viscosity of the entire resin layer (B) or the surface layer is preferably 50 Pa · s to 500 Pa · s. Examples of the material of the spacer include resin, silica and glass fiber. Examples of the resin system include a melamine resin, a urea resin, a benzoguanamine resin, a polystyrene resin, and the like, and these may be colored in black or the like. The lower part of each integrated spacer is coated with a thermoplastic or thermosetting resin forming the substrate, and the spacer is fixed by the adhesive force of the resin.
The cell gap can be adjusted by changing the viscosity in a state before the thermoplastic or thermosetting resin layer is cured, for example, in a semi-cured state. For example, when the viscosity of the resin melt layer before curing, for example, in a semi-cured state, is low, the ratio of the portion of each spacer that is covered with the resin increases, and the cell gap decreases. On the other hand, when the viscosity is high, the proportion of the portion of each spacer that is covered with the resin decreases, and therefore the cell gap increases.

The support is usually in the form of a belt, and specific examples include an endless belt for casting. Examples of the material thereof include glass, plastic, and the like in addition to metals such as stainless steel, body, and aluminum, and stainless steel is most preferably used. The surface roughness of the support is preferably 0.02 μm or less. Surface roughness 0.02μm
If it is larger than this, a mirror-surfaced resin sheet cannot be obtained.

An easily peelable resin layer (A) for coating a support.
For the formation of the resin, any suitable resin which does not adhere to the support or has a weak adhesive force even when adhered and can be easily peeled off from the support can be used, and is not particularly limited. Incidentally, examples of the resin according to, urethane resin and acrylic resin, polyester resin and polyvinyl alcohol,
Examples thereof include a polyvinyl alcohol resin such as an ethylene vinyl alcohol copolymer, a vinyl chloride resin, and a vinylidene chloride resin.

Further, polyarylate resin, sulfone resin, amide resin, imide resin, polyether sulfone resin, polyetherimide resin, polycarbonate resin, silicone resin, fluorine resin, polyolefin resin, Styrene-based resins, vinylpyrrolidone-based resins, cellulose-based resins, acrylonitrile-based resins, and the like can also be used for forming the resin layer. In forming the resin layer, a blend of two or more kinds of appropriate resins may be used.

When stainless steel is used as the support,
Particularly, a urethane-based resin is preferable from the viewpoint of release characteristics, and a resin represented by the following structural formula is particularly preferably used.

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Further, since the easily peelable resin layer (A) can function as a surface coat layer, for example, chemical resistance, surface hardness, optical anisotropy, low water absorption, low moisture permeability, low oxygen permeability. The material can also be selected for the purpose of imparting functions such as gas barrier properties such as properties.

Therefore, the easily peelable resin layer (A) is formed by, for example, superposing a polyvinyl alcohol-based resin layer for providing gas barrier properties on a urethane-based resin layer for providing easy peelability. Like a layer, it may be formed as a multi-layered material in addition to a single-layered material for the purpose of imparting other functions in addition to easy peelability.

As a method of applying the easily peelable resin layer (A) to the surface of the support, a solution in which the above resin is dissolved in an appropriate organic solvent or water is applied to the support, dried, and then dried. Curing by heating or light irradiation. Examples of the coating method include roll coating, spin coating, wire bar coating, extrusion coating, curtain coating, spray coating, dip coating, and the like. Extrusion coating is particularly preferred from the viewpoint of coating efficiency and the like.

In this case, the viscosity of the easily peelable resin solution is preferably 100 mPa · s or less. If the viscosity of the resin solution is larger than 100 mPa · s, the operability is deteriorated.
In the case of an extrusion coat, it is particularly 1 to 10 m.
Pa · s is preferred.

When the resin layer (A) is cured by the light irradiation, a high-pressure UV lamp (center wavelength: 365 nm),
A low-pressure UV lamp (center wavelength: 254 nm) is preferably used.

In the present invention, the thickness of the easily peelable resin layer (A) is preferably from 1 to 10 μm, more preferably from 2 to 10 μm.
5 μm is preferred. This is because if it is 1 μm or less, the releasability from the support is deteriorated, and if it is 10 μm or more, cracks occur in the resin layer (A).

In the present invention, the resin developed as the thermoplastic or thermosetting resin layer (B) includes polycarbonate, polyarylate, polyether sulfone,
Examples thereof include thermoplastic resins such as polysulfone, polyester, polymethyl methacrylate, polyetherimide, and polyamide, and thermosetting resins such as epoxy resin, unsaturated polyester, polydiallyl phthalate, and polyisobonyl methacrylate. One or more of these resins can be used, and they can be used as a copolymer or a mixture with other components.

Among them, epoxy resins are particularly preferably used. Examples of the epoxy resins include bisphenol A type and bisphenol F.
Type, bisphenol S type and bisphenol type such as water addition, novolak type such as phenol novolak type and cresol novolak type, nitrogen-containing ring type such as triglycidyl isocyanurate type and hydantoin type, alicyclic type and aliphatic type Aromatic type such as naphthalene type, glycidyl ether type, low water absorption type such as biphenyl type, dicyclo type, ester type and ether ester type, and modified forms thereof. These may be used alone or in combination. Among the above various epoxy resins, it is preferable to use a bisphenol A type epoxy resin, an alicyclic epoxy resin, or a triglycidyl isocyanurate type from the viewpoint of anti-discoloration properties.

As such an epoxy resin, those having an epoxy equivalent of 100 to 1000 and a softening point of 120 ° C. or lower are preferably used from the viewpoint of physical properties such as flexibility and strength of the obtained resin sheet. From the viewpoint of obtaining an epoxy resin-containing liquid having excellent coating properties and spreadability into a sheet, etc., a two-liquid mixed type liquid which shows a liquid state at a temperature lower than the temperature at the time of coating, particularly at room temperature, can be preferably used.

The epoxy resin includes a curing agent, a curing accelerator, and if necessary, an antioxidant, a denaturant, a surfactant, a dye, a pigment, a discoloration inhibitor,
Various conventionally known additives such as an ultraviolet absorber can be appropriately compounded.

The curing agent is not particularly limited.
One or more appropriate curing agents depending on the epoxy resin can be used. Incidentally, examples thereof include organic compounds such as tetrahydrophthalic acid and methyltetrahydrophthalic acid, hexahydrophthalic acid and methylhexahydrophthalic acid, ethylenediamine and propylenediamine, diethylenetriamine and triethylenetetramine, and their amine adducts and meta 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 and isopropylimidazole, 2,4-dimethylimidazole and phenylimidazole; Imidazole compounds such as undecyl imidazole, heptadecyl imidazole, and 2-phenyl-4-methylimidazole are also examples of the curing agent.

Further, methylimidazoline, 2-ethyl-4-methylimidazoline, ethylimidazoline and isopropylimidazoline, 2,4-dimethylimidazoline and phenylimidazoline, undecylimidazoline and heptadecylimidazoline, and 2-phenyl-4-methylimidazoline Examples of the curing agent include imidazoline compounds, phenol compounds, urea compounds, and polysulfide compounds.

In addition, acid anhydride compounds and the like are also mentioned as examples of the curing agent, and from the viewpoint of preventing discoloration, such acid anhydride curing agents can be preferably used. Examples include phthalic anhydride and maleic anhydride, trimellitic anhydride and pyromellitic anhydride, nadic anhydride and glutaric anhydride, tetrahydrophthalic anhydride and methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride and Examples include methylhexahydrophthalic anhydride, methylnadic anhydride, dodecenylsuccinic anhydride, dichlorosuccinic anhydride, benzophenonetetracarboxylic anhydride, and chlorendic anhydride.

In particular, they are colorless or pale yellow, such as phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride and 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 mix so as to be 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 worse,
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 of use can be in accordance with the above-mentioned equivalent ratio.

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

The amount of the curing accelerator 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 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 antioxidant include conventionally known compounds such as phenol compounds, amine compounds, organic sulfur compounds and phosphine compounds.

Examples of the denaturing agent include conventionally known agents such as glycols, silicones and alcohols.

The surfactant is added to smooth the surface of the epoxy resin sheet when the epoxy resin sheet is formed by the casting method while exposing the epoxy resin to air. Examples of the surfactant include a silicone type, an acrylic type, and a fluorine type, and a silicone type is particularly preferable.

FIG. 1 shows an embodiment of a manufacturing process according to the present invention.
It was shown to. In the manufacturing process illustrated in FIG. 1, a resin sheet is continuously manufactured by a casting method using an endless belt as a support.

In the casting method illustrated in FIG. 1, the support made of the endless belt 1 is interposed between the driving drum 4 and the driven drum 5, for example, 0.1 to 50 m / min, preferably 0.2 to 5 m. / Min while running at a constant speed, applying a resin-containing liquid for coating the support through the dies 7 and 9 and drying or, if necessary, performing a curing treatment by heating or light irradiation or the like. , 11. In the illustrated example, the heating device 3 and the UV curing device 8 are arranged.

Next, a liquid containing a thermoplastic or thermosetting resin is applied onto the films 10 and 11 through the die 2 and developed into a sheet, which is then semi-cured by heating or light irradiation. Next, after the spacers are sprayed by the dry spacer spraying device 13, the thermoplastic or thermosetting resin-containing liquid is completely cured by heating or light irradiation, and the spacers are fixed to form the coating 6. In the illustrated example, a heating device 3 is provided, and the heating method is performed by hot air, an infrared heater, or the like, and these may be used in combination. Hot air speed is usually 0.1 ~
The heating speed is 5 m / sec, but in the case of heating a liquid containing a thermoplastic or thermosetting resin, the heating speed is preferably 0.2 to 1 m / sec.

The heating device 3 is preferably divided into 1 to 10 zones, more preferably 2 zones, in order to reduce the viscosity of the resin-containing liquid depending on the temperature and to control the viscosity change caused by the thickening due to the curing reaction. ~ 6 zones are good. In each zone, heating can be performed on the upper surface, the lower surface, or both surfaces of the endless belt. Heating temperature is 30
~ 250 ° C is preferred. Heating temperature accuracy is ± 0.5 ° C / c
m or less, more preferably ± 0.1 ° C./cm
The following is good. When the heating temperature is lower than 30 ° C., in the case of a thermoplastic resin, the solvent of the resin-containing liquid is difficult to volatilize, and it takes time to cure. In the case of a thermosetting resin, the resin hardly hardens. If the heating temperature exceeds 250 ° C., in the case of a thermoplastic resin, the solvent of the resin-containing liquid tends to bump, which is problematic in terms of operability. In the case of a thermosetting resin, the viscosity of the resin-containing liquid decreases, so that the accuracy of the thickness of the resin sheet deteriorates. If the heating temperature accuracy is more than ± 0.5 ° C./cm, the accuracy of the thickness of the resin sheet deteriorates, and the appearance is likely to be poor.

The temperature of the die 2 for discharging the liquid containing the thermoplastic or thermosetting resin is preferably from 10 to 40 ° C.
More preferably, the temperature is 20 to 30C. The temperature accuracy of the die is preferably ± 0.5 ° C. or less, more preferably ± 0.5 ° C.
0.1 ° C or less is preferable. When the temperature of the die is lower than 10 ° C., the viscosity of the resin-containing liquid increases in both the thermoplastic resin and the thermosetting resin, so that there is a problem in operability. If the temperature is higher than 40 ° C., in the case of a thermoplastic resin, the solvent of the resin-containing liquid tends to volatilize, and the resin adheres to the discharge port of the die. In the case of a thermosetting resin, application of the resin becomes difficult because the curing of the resin proceeds in the die. If the temperature accuracy of the die is larger than ± 0.5 ° C., the accuracy of the thickness of the resin sheet is deteriorated, and the appearance is likely to be poor.

The viscosity of the thermoplastic or thermosetting resin-containing liquid to be discharged is preferably from 0.1 Pa · s to 50 Pa · s, and 15 Pa · s when performing extrusion coating.
s to 30 Pa · s is preferred. When the viscosity of the resin-containing liquid is less than 0.1 Pa · s, the accuracy of the thickness of the resin sheet becomes poor. When the viscosity of the resin-containing liquid exceeds 50 Pa · s, the operability deteriorates.

As a method for applying the liquid containing a thermoplastic or thermosetting resin, a curtain coat, an extrusion coat, a roll coat and the like are preferable, and an extrusion coat is particularly preferable.

A guide roll is provided on the back surface of the endless belt of the heating device, and the horizontal level can be adjusted by a horizontal level sensor. The horizontal level of the support is preferably 1 mm / (5 × effective width) mm or less, more preferably 1 mm / (40 × effective width) mm or less. When the horizontal level is larger than 1 mm / (5 × effective width) mm, the accuracy of the thickness of the resin sheet becomes poor.

A weir for preventing liquid flow may be provided on both sides of the support with a heat-resistant resin. Specifically, polyethylene terephthalate and the like are preferably used.

In recovering the resin sheet from the support, a peeling means can be used if necessary. Further, it is preferable to perform such recovery in a high-temperature atmosphere at a temperature equal to or higher than the glass transition point from the viewpoint of preventing cracking. Further, the formed resin sheet in a continuous state can be collected by cutting into appropriate dimensions through appropriate cutting means such as a laser beam, an ultrasonic cutter, dicing, or a water jet. According to the casting method, the production speed can be easily controlled by adjusting the moving speed of the spreading layer through the support, and the thickness of the resin sheet obtained by adjusting the moving speed and the spreading amount can be easily controlled. can do.

The resin sheet according to the present invention can be preferably used for various applications, and is also preferably used as an optical sheet such as a liquid crystal cell substrate, an antireflection sheet, a prism sheet and a diffusion sheet.

A liquid crystal display device is generally formed by appropriately assembling components such as a polarizing plate, a liquid crystal cell, a reflector 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-described resin sheet is used as the substrate of the liquid crystal cell, and a liquid crystal display device can be formed according to the related art. Therefore, in forming a liquid crystal display device, for example, a light diffusing plate, an antiglare layer, an antireflection film, a protective layer, a protective plate provided on a polarizing plate on the viewing side, or a compensation device provided between the liquid crystal cell and the polarizing plate on the viewing side. An appropriate optical component such as a retardation plate can be combined with the resin sheet.

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

Example 1: 400 parts (parts by weight, the same applies hereinafter) of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate represented by the chemical formula (Chemical Formula 2) and the chemical formula (Chemical Formula 3) 500 parts of methylhexahydrophthalic anhydride, 15 parts of tetra-n-butylphosphonium o, o-diethylphosphorodithioate represented by the chemical formula, 9 parts of glycerin, and a silicone surfactant as a surfactant One part of the agent was stirred and mixed to prepare an epoxy resin-containing liquid.

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Next, a 17% by weight toluene solution of a urethane-based UV-curable resin is discharged from the die 7 by the casting method illustrated in FIG. 1 and the belt is run on a stainless steel endless belt 1 (surface roughness Ra = 10 nm). After casting and coating at a speed of 0.2 m / min, and volatilizing and drying the toluene at 60 ° C., a UV curing device 8 was used.
(Center wavelength 254 nm, integrated light amount 2000 mJ / c
m ² ) to form a urethane resin layer having a thickness of 2 μm and a width of 500 mm.

Subsequently, a 5.5% by weight aqueous solution of a polyvinyl alcohol-based resin was discharged from the die 9 and cast onto the urethane-based resin layer at a running speed of 0.2 m / min.
For 10 minutes to form a polyvinyl alcohol-based resin layer having a thickness of 4 μm and a width of 450 mm.

Next, a heat-resistant polyethylene terephthalate base tape having a width of 40 mm (MT-3 manufactured by Nitto Denko Corporation) is provided on both sides of the urethane resin layer and the polyvinyl alcohol resin layer.
155) and apply the epoxy resin-containing liquid (20P
a · sat 25 ° C.) is discharged from the die 2 while controlling the die temperature to 25 ° C., and a coating width 430 is applied to the surface of the resin layer.
mm. Next, it was cured by a heating device at a running speed of 0.2 m / min. The heating device 3 is divided into five zones, and the length of one zone is 1 m. This time, Zone 1 is 90 ° C, Zone 2 is 120 ° C, Zones 3-5
Was controlled at 140 ° C. Next, by moving the epoxy resin-containing liquid from zone 1 to zone 5, 90 ° C.
Cured at × 5 minutes, 120 ° C. × 5 minutes, 140 ° C. × 15 minutes, peeled between the stainless steel endless belt and the urethane resin layer on the drum 5 controlled at 130 ° C., and obtained a 430 mm wide epoxy resin sheet. (A) was obtained. In this case, the horizontal level of the support in the heating unit is set to 200 μm / 100.
The support was heated with hot air from above and below, and the temperature accuracy was set to 0.4 ° C./cm.

The obtained resin sheet was 490 m long in the machine direction.
Cutting was performed at intervals of m to obtain a size of 490 mm × 490 mm. The average value of the thickness of the obtained epoxy resin sheet (a) was 400 μm, and the standard deviation was 7 μm. The average value and the standard deviation of the thickness are 480 mm × 480.
It was determined by measuring 60 points in the plane of mm. The surface roughness is Ra = 0.2 nm on the epoxy resin side (free surface side),
Ra = 10 nm on the urethane resin side (belt surface side). In addition, the surface roughness is an average value measured at 10 points in a plane of 480 mm × 480 mm.

Subsequently, the epoxy resin-containing liquid was poured from the die 2.
Until the ink is ejected, the same operation as above is performed, and
The epoxy resin-containing liquid is in a semi-cured state (300 Pa · s)
And a silica-based spherical spec
Laser (φ5μm) 1mm ^TwoSpray about 80 pieces per
And cured at 165 ° C for 0.5 hour.
(B) was obtained. The deviation of the spacer diameter is ±
Those having a thickness of 0.02 to 0.04 μm were used.

Next, the obtained resin sheet (b) was cut at intervals of 490 mm in the flow direction, and cut at 490 mm × 490 m
m. The obtained resin sheet (b) was provided with hemispherical projections (5.0 μm to 5.1 μm).
The thickness of the resin sheet (b) is 200 μm on average, excluding protrusions
m, standard deviation was 6 μm. The surface roughness is R on the epoxy resin side (the free surface side where there is no spacer).
a = 0.2 nm, R on the urethane resin side (belt surface side)
a = 10 nm. The surface roughness is 480 mm
It is an average value measured at 10 points in a plane of × 480 mm.

Using the obtained epoxy resin sheets (a) and (b), ITO (transparent electrode) was formed on the epoxy resin side.
Was sputtered, an aqueous solution of polyvinyl alcohol was dipped thereon to form an alignment film, and a rubbing treatment was performed to prepare a 240 ° twisted STN liquid crystal cell. A nematic liquid crystal and a chiral agent were used for the liquid crystal.

Next, a retardation film for compensating for a black state was laminated on the STN liquid crystal cell, and a polarizing plate was further laminated to obtain a liquid crystal display device. Next, a black display was performed by applying a voltage to the liquid crystal display device. Observation with a deflection microscope revealed that good black display was obtained without defective alignment. When the cell gap was measured, the average was 5 μm and the standard deviation was 0.025 μm.
m. The cell gap was measured at 300 mm x 3
This is an average value measured at 10 points in a plane of 00 mm.

Example 2 An STN liquid crystal cell was prepared in the same manner as in Example 1, except that the average thickness of the epoxy resin sheet (b) was 300 μm and the standard deviation was 8 μm.

Next, a retardation film for compensating for a black state was laminated on the STN liquid crystal cell, and a polarizing plate was further laminated to obtain a liquid crystal display device. Next, a black display was performed by applying a voltage to the liquid crystal display device. Observation with a deflection microscope revealed that good black display was obtained without defective alignment. When the cell gap was measured, the average was 5 μm and the standard deviation was 0.025 μm.
m. The cell gap was measured at 300 mm x 3
This is an average value measured at 10 points in a plane of 00 mm.

Example 3 An STN liquid crystal cell was prepared in the same manner as in Example 1, except that the average thickness of the epoxy resin sheet (b) was 400 μm and the standard deviation was 11 μm.

Next, a retardation film for compensating for a black state was laminated on the STN liquid crystal cell, and a polarizing plate was further laminated thereon to obtain a liquid crystal display device. Next, a black display was performed by applying a voltage to the liquid crystal display device. Observation with a deflection microscope revealed that good black display was obtained without defective alignment. When the cell gap was measured, the average was 5 μm and the standard deviation was 0.025 μm.
m. The cell gap was measured at 300 mm x 3
This is an average value measured at 10 points in a plane of 00 mm.

Comparative Example 1: Two epoxy resin sheets (a) prepared in Example 1 were used, and a silica spacer (φ5 μm) was fixed to one epoxy resin sheet (a) for cell gap adjustment. A STN liquid crystal cell was prepared in the same manner as in Example 1, except that the mixture was sprayed without being applied and another epoxy resin sheet (a) was attached.

A retardation film for compensating for a black state was laminated on the prepared STN liquid crystal cell, and a polarizing plate was further laminated thereon to obtain a liquid crystal display device. Next, black was displayed by applying a voltage to the liquid crystal display device, and observation was performed with a deflection microscope. As a result, light leakage was observed due to deformation of the substrate due to displacement of the spacer during bonding.

[0063]

According to the present invention, troubles such as a displacement of a spacer in a cell gap adjusting step of a liquid crystal display device using a resin sheet made of a thermoplastic or thermosetting resin are eliminated, and the process is simplified. As a result, a good display quality without color unevenness can be obtained by making the cell gap uniform.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a production process by a casting method.

[Explanation of symbols]

 1: endless belt (support) 2: thermoplastic or thermosetting resin coating die 3: heating device 4: drive drum 5: driven drum 6: thermoplastic or thermosetting resin layer 7: first resin coating die 8: UV curing device 9: Second resin application die 10: Second resin layer 11: First resin layer 12: End reinforcing tape 13: Dry spacer spraying device

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kiichi Shimohira 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation (72) Inventor Yoshimasa Sakata 1-1-2 Shimohozumi, Ibaraki-shi, Osaka No. Nitto Denko Corporation (72) Inventor Minoru Miyatake 1-2-1, Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation F-term (reference) 2H089 LA20 NA05 QA14 TA01 TA11 TA15 TA18 2H090 JB03 LA05 LA09 LA16 4F205 AA29 AA36 AA39 AA42 AA44 AB17 AG03 AH42 GA07 GB01 GB26 GB29 GC07 GE06 GE11 GE25 GF02 GF24 GN13 GW06 GW23

Claims (4)

[Claims] A substrate is made of a thermoplastic or thermosetting resin, and a spacer used for controlling a distance between two substrates disposed opposite to each other with a liquid crystal layer interposed therebetween is used as a spacer without using an adhesive substance. Integrated resin sheet. 2. The method according to claim 1, wherein the density of the spacer is 10%.
Resin sheet characterized by having a number of pieces / mm ^{2 to} 10,000 pieces / mm ² . 3. A method for continuously manufacturing a resin sheet in which a spacer used for controlling a distance between two substrates disposed opposite to each other with a liquid crystal layer interposed therebetween is integrated with a substrate. A thermoplastic or thermosetting resin layer (B) is spread on the support coated with (A), and a resin layer (B)
A method for producing a resin sheet, comprising a step of curing a resin layer (B) after dispersing spacers on a substrate, and fixing the spacers without using an adhesive substance. 4. A liquid crystal display device using the resin sheet according to claim 1.