JPH05309794A - Optical laminated sheet and production thereof - Google Patents

Abstract

PURPOSE:To enhance adhesiveness and surface smoothness by laminating a resin layer cured by a specific active energy beam on a photo-isotropic sheet and respectively specifying the surface roughness of the resin cured layer, the retardation value of the whole of a laminated sheet and visible light transmissivity. CONSTITUTION:An optical laminated sheet is constituted by laminating a resin layer containing a polyisocyanate compd. cured by an active energy beam on a single-layer or double-layer photo-isotropic sheet 1. The surface roughness of the free surface of the resin layer 2 is set to 0.5mum or less. The retardation value of the whole of a laminated sheet is set to 60mm or less and the visible light transmissivity of the laminated sheet is set to 60% or more. At the time of production, a resin solution curable by an active energy beam is supplied to the gap between the photo-isotropic sheet 1 and a smoothing casting material 3 and subsequently cured by the irradiation with an active energy beam to form the active energy beam curable resin cured layer 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical laminated sheet having extremely excellent surface smoothness, and more particularly to an optical laminated sheet suitable for an electrode substrate for manufacturing a liquid crystal display panel. It also relates to a method for industrially producing such an optical laminated sheet.

[0002]

2. Description of the Related Art Conventionally, glass has been used as a substrate for liquid crystal display transparent electrodes, but it cannot be made thin.
Due to problems such as inferior impact resistance and difficulty in mass production, plastic substrates have recently been used more frequently, and the applicant has also filed several applications as described below. There is.

For example, in Japanese Patent Laid-Open No. 63-71829, an aqueous anchor coat layer is provided on at least one surface of a base material layer made of a sheet of polycarbonate resin or the like and having a retardation value of 30 nm or less. There is shown an electrode substrate for a liquid crystal display panel, in which a single-layer or multi-layer protective layer made of a cured product of an air-permeable resin and / or a crosslinkable resin is provided thereon.

In JP-A-64-50021, a laminate of a gas-permeable synthetic resin film layer and a cured crosslinkable resin layer is adhered to each other with their gas-permeable synthetic resin film layer surfaces facing each other. An electrode substrate for a liquid crystal display panel is shown which has a structure in which it is laminated and integrated via an agent layer.

In JP-A-64-50022, a cross-linking agent capable of reacting with the gas-permeable synthetic resin film layer is used on both sides of the gas-permeable synthetic resin film layer formed by a casting method. There is disclosed a method for producing an electrode substrate for a liquid crystal display panel, in which the cured crosslinkable resin layer is directly formed by a casting method.

Japanese Patent Laid-Open No. 2-137922 discloses a retardation value of 30 having a resin layer having no solvent resistance.
For the production of liquid crystal display panels in which an alcohol-soluble UV-curable adhesive layer or a water-based thermosetting adhesive layer is laminated on the resin layer side of a substrate sheet having a thickness of nm or less, and a release sheet is further laminated on the adhesive layer. Is shown as an example of a base sheet, and a sheet having a layer structure of a resin sheet such as polycarbonate / anchor coating layer / air-permeable synthetic resin layer / phenoxyether-based crosslinked polymer layer is shown as an example of the base sheet. I have been given.

In Japanese Patent Application Laid-Open No. 2-149819, the electrode support film side of an electrode support film with a transparent electrode having a structure in which a transparent electrode is provided on one surface of an electrode support film that can be wound into a roll is referred to as a retardation value. Shows a liquid crystal cell substrate with a transparent electrode laminated and integrated on a base material having a light transmittance of 80 nm or less and a light transmittance of 60% or more. As an example of an electrode supporting film, a resin film layer / anchor coating layer / crosslinking is shown. Cured resin layer, resin film layer / anchor coating layer / air permeable synthetic resin film layer / crosslinkable resin cured product layer, crosslinkable resin cured product layer / air permeable synthetic resin film layer / anchor coating layer / resin film Layer / anchor coating layer / air-permeable synthetic resin film layer / crosslinkable resin cured material layer, crosslinkable resin cured material layer / air-permeable synthetic resin layer Film having a layer structure such as a film layer / adhesive layer / penetration resistance temper synthetic resin film layer / crosslinkable resin cured material layer is raised.

[0008]

When the above-mentioned sheet-like substrate is used as an electrode substrate for manufacturing a liquid crystal display panel, a transparent electrode such as ITO is formed on the cured crosslinkable resin layer, and further thereon. After the alignment film is provided on, the liquid crystal cell is assembled. In this case, the liquid crystal that can be contained between the substrates is TN.
In the case of (twisted nematic) liquid crystal, some irregularities on the substrate surface on the transparent electrode formation side have almost no effect on product quality. This is because a liquid crystal display panel assembled from a liquid crystal cell using TN liquid crystal has an achromatic color, and if the light and shade are clear, the panel is acceptable.

However, when the liquid crystal contained between the substrates is STN (super twisted nematic) liquid crystal, the STN liquid crystal has a gap of, for example, about 270 ° although the gap between the substrates is only about 5 to 6 μm. Due to the twisting, even if there is a slight unevenness on the substrate surface on the transparent electrode formation side, the display may be colored purple, green, etc. and the screen may be very difficult to see. It was the biggest weakness of the LCD panel. The electrode substrate according to the applicant's application cited above has not sufficiently solved this problem.

Under such a background, the present invention provides an optical laminated sheet having an extremely excellent surface smoothness, particularly an optical laminated sheet suitable for an electrode substrate for manufacturing a liquid crystal display panel, and the same. It is an object of the present invention to provide a method for industrially producing such an optical laminated sheet.

[0011]

The optical laminated sheet of the present invention comprises a single-layer or multi-layered optically isotropic sheet (1), and an active energy ray-curable resin cured layer (a cured layer containing a polyisocyanate compound). 2) is provided, and the surface roughness of the free surface of the active energy ray-curable resin cured layer (2) is 0.5 μm or less, the retardation value of the entire laminated sheet is 60 nm or less, and the visible light transmission. The rate is 60% or more. In this case, it is preferable to use the optically isotropic sheet (1) in which at least the surface layer is a gas permeation resistant resin layer.

Further, the method for producing an optical laminated sheet of the present invention comprises a polyisocyanate compound in the gap between the single-layer or multi-layer optically isotropic sheet (1) and the smoothing template material (3) having a smooth surface. The resin liquid (2a) of the active energy ray-curable resin composition containing (2a) is supplied so that the resin liquid (2a) is sandwiched between the two layers, and then the sandwiching layer ((a) is irradiated by irradiation with active energy rays. 2b) is cured to form an active energy ray curable resin cured layer (2).

The present invention will be described in detail below. The terms "sheet", "film", and "layer" all mean thin layers, and do not limit the thickness.

The optically isotropic sheet (1) is preferably a single-layer or multiple-layer optically isotropic sheet in which at least the surface layer is a gas-proof resin layer.

The air-permeable resin constituting the air-resistant resin layer includes, for example, a layer formed from a polymer containing 50 mol% or more of an acrylonitrile component, a vinyl alcohol component or a vinylidene halide component. Polymers having a hydroxyl group such as polyvinyl alcohol or copolymer modified products or graft products thereof, and ethylene-vinyl alcohol copolymer having an ethylene content of 15 to 50 mol% are important.

The air-permeable resin layer is usually formed by a casting method, and its oxygen permeability (measured according to ASTM D-1434-75) is 30 cc / 24 hr · m ² · atm or less, especially 20 cc / 24 hr · m ² ·
Atm or less, more preferably 10 cc / 24 hr · m ² · atm or less. The air-permeable resin layer has a thickness of 1 to 50 μm
In particular, it is suitable to set in the range of 2 to 20 μm.

Examples of layers other than the air-permeable resin layer constituting the optically isotropic sheet (1) include a base material layer and a cured crosslinkable resin layer. An example of the layer structure of the optically isotropic sheet (1) is
Air-permeable resin layer, air-permeable resin layer / air-permeable resin layer, air-permeable resin layer / base material layer, air-permeable resin layer / base material layer / air-permeable resin layer, air-permeable resin layer / Substrate layer / air-proof resin layer / crosslinkable resin cured material layer and the like. In the case of a laminated structure, an anchor coating layer or an adhesive layer can be provided between the layers, if necessary.

In the above, as the base material layer, polycarbonate, polymethylmethacrylate, polyethersulfone, polysulfone, polyarylate, amorphous polyolefin, polyparabanic acid resin, polyamide or the like is used.

The base layer preferably has a heat distortion temperature of 80 ° C. or higher. The base material layer is obtained by a casting method or an extrusion method,
The thickness is often about 30 μm to 3 mm.

Among the above, examples of the crosslinkable resin in the cured crosslinkable resin layer include a phenoxy ether type crosslinkable resin, an epoxy resin, an acrylic resin, an acrylic epoxy resin, a melamine resin, a phenol resin or a urethane resin.

Among the crosslinkable resins, a particularly preferable resin is a phenoxy ether type polymer represented by the following chemical formula 1.

[0022]

[Chemical 1]

(Wherein R ^{1 to} R ⁶ are each hydrogen, a lower alkyl group having 1 to 3 carbon atoms or Br, R ⁷ is a lower alkylene group having 2 to 4 carbon atoms, m is an integer of 0 to 3, n is 2
It means an integer of 0 to 300, respectively. )

A phenoxy ether type cross-linked polymer is obtained by subjecting the hydrogen portion of the hydroxyl group of this polymer to a cross-linking reaction with a polyfunctional compound as a cross-linking agent. As the cross-linking agent (polyfunctional compound) to be reacted to obtain a cross-linked polymer, a group having a high reaction activity with a hydroxyl group, for example, an isocyanate group,
A compound having two or more carboxyl groups, a reactive group in the carboxyl group (for example, a halide, an active amide, an active ester, an acid anhydride group, etc.), mercapto or the like is used, and polyisocyanate is particularly important. ..

Among the above, as the acrylic resin, at least 3 or more acryloyloxy groups or /
And a composition containing a polyfunctional unsaturated monomer containing a compound containing a methacryloyloxy group (hereinafter referred to as a compound containing a polyfunctional (meth) acryloyloxy group) as a main component and / or an initial radical reactant thereof as a main component I can give you things. Particularly preferred is a polyfunctional unsaturated monomer containing at least 3 or more (meth) acryloyloxy groups in the molecule, in an amount of 50% by weight or more, preferably 70% by weight, based on all unsaturated monomers. , Particularly preferably 90
It is a composition comprising an unsaturated monomer mixture or / and its initial radical reactant, which is contained in an amount of not less than wt%.

As the active energy ray-curable resin constituting the active energy ray-curable resin cured layer (2), a prepolymer or / and a monomer having photopolymerizability, and optionally other monofunctional or polyfunctional monomer, Various polymers,
A resin composition containing a photopolymerization initiator and a sensitizer is used.

Examples of the photopolymerizable prepolymer include polyester acrylate, polyester urethane acrylate, epoxy acrylate and polyol acrylate, and examples of the photopolymerizable monomer include monofunctional acrylate, bifunctional acrylate and trifunctional or higher functional acrylate. Are exemplified. Of these, epoxy acrylates, which have good physical properties after curing, are particularly useful, so it is desirable to use at least part of them.

As the photopolymerizable prepolymer or monomer, in addition to the above, a phosphazene resin represented by the following chemical formula 2 can be used.

[0029]

[Chemical 2]

When the active energy ray curable resin is an ultraviolet curable resin, a small amount of a photoinitiator or a sensitizer is usually used in combination, but depending on the kind of the resin, it is cured even if it is irradiated with ultraviolet rays without blending them. There are cases. As the photoinitiator, various photocuring agents such as acetophenones, benzophenones, Michler's ketone, benzyl, benzoin, benzoin ether, benzyl ketals and thioxanthones are used, and as sensitizers, amines and diethylaminoethyl methacrylate are used. Various sensitizers are used.

In the present invention, as the active energy ray-curable resin cured layer (2), a cured layer formed of an active energy ray-curable resin containing a polyisocyanate compound is used.

Examples of the polyisocyanate compound include tolylene diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate or modified products thereof, isophorone diisocyanate, tolidine diisocyanate, lysine diisocyanate, xylylene diisocyanate, naphthalene diisocyanate, tetramethyl xylene diisocyanate, p-phenylene. Examples thereof include various polyisocyanates including diisocyanate, adducts and prepolymers of these polyisocyanates, and derivatives of relatively long-chain aliphatic polyisocyanates such as hexamethylene diisocyanate are particularly preferable.

The compounding amount of the polyisocyanate compound is 3 to the whole active energy ray-curable resin cured layer (2).
It is preferable to occupy about 30% by weight, and when the blending amount is too small, the effect of improving the adhesiveness with the air-permeable resin layer is small, while when it exceeds the allowable range and is too large,
The hardness of the active energy ray-curable resin cured layer (2) is reduced, and the adhesiveness to the air-permeable resin layer is reduced, impairing its practicality.

The resin composition usually does not contain a solvent, but a small amount of solvent may be used together if necessary.

The thickness of the active energy ray-curable resin cured layer (2) can be set appropriately, but it is from 1 to 20 μm, particularly from 2-1.
It is often 0 μm.

The optical laminated sheet of the present invention is preferably produced by the following first method. That is, by supplying a resin liquid (2a) of an active energy ray-curable resin composition containing a polyisocyanate compound in the gap between the optically isotropic sheet (1) and the smoothing template material (3) made of a smooth film. The resin liquid (2a) is sandwiched between both layers. The optically isotropic sheet (1) is used as a film-forming roll (4a) on a smoothing template material (3).
Are previously supplied to the film-forming rolls (4b), and the gap between the film-forming rolls (4a) and (4b) is adjusted to a predetermined value. The film forming rolls (4a) and (4b) are configured so that they can be kept warm as necessary.

Then, the sandwiching layer (2b) is cured by irradiation with active energy rays to form an active energy ray-curable resin cured layer (2). Examples of active energy rays include ultraviolet rays and electron rays. The cumulative amount of light and dose during irradiation with active energy rays are set in the optimum range in consideration of the thickness of the active energy ray-curable resin cured layer (2), etc., and the smooth release property and activity of the smoothed template material (3) are set. The energy ray-curable resin cured layer (2) should have solvent resistance.

As a result, a laminate comprising the optically isotropic sheet (1) / active energy ray-curable resin cured layer (2) / smoothing template material (3) can be obtained, so that it can be obtained at any stage after that. The smoothing template material (3) is peeled off from the layered product to obtain a layered sheet comprising the optically isotropic sheet (1) / active energy ray curable resin cured layer (2).

As the smoothing template material (3) in the above,
Biaxially oriented polyester film such as biaxially oriented polyethylene terephthalate sheet, biaxially oriented polybutylene terephthalate sheet, biaxially oriented polyethylene naphthalate sheet, or biaxially oriented polypropylene film is used. Stretched polyethylene terephthalate film is of particular importance. In this case, if the surface is subjected to corona discharge or flame treatment, it will be difficult to peel the smoothing template material (3) in the subsequent steps, so be careful to use one that is not subjected to such treatment. ..

The surface roughness of these smooth films is
0.15 μm or less, preferably 0.1 μm or less, further 0.05
When the surface roughness is required to be not more than 0.1 μm and the surface roughness exceeds 0.15 μm, an optical laminated sheet having desired smoothness cannot be obtained. Among the above-mentioned biaxially stretched polyethylene terephthalate films, which do not contain a filler, the surface smoothness is remarkably improved by the biaxial stretching, so that the smoothness can be maximized.

Second Process for Producing Laminated Optical Sheet of the Present Invention
The method of casting the resin solution (2a) of the active energy ray-curable resin composition in which a polyisocyanate compound is mixed with one of the smoothing template material (3) consisting of the optically isotropic sheet (1) or the smooth film is cast. Then, while controlling the thickness of the sandwiching layer (2b) by the gap between the rolls while covering the casting layer with the smoothing template material (3) or the optically isotropic sheet (1), In this method, the sandwiching layer (2b) is cured by irradiation to form an active energy ray-curable resin cured layer (2).

Third Process for Producing Laminated Optical Sheet of the Present Invention
In the method, a resin solution (2a) of an active energy ray-curable resin composition containing a polyisocyanate compound is cast on an optically isotropic sheet (1), and a smoothing template material is applied to the casting layer.
While controlling the thickness of the sandwiching layer (2b) while pressing the smoothed glass as (3), the sandwiching layer (2b) is cured by irradiation with active energy rays to cure the active energy ray-curable resin cured layer ( 2) and the method. In this way,
Reuse the glass used.

The surface roughness of the free surface of the active energy ray-curable resin cured layer (2) of the laminated sheet obtained by each of the above methods depends on the degree of surface smoothness of the smoothing template material (3) and the like. , 0.5 μm or less, preferably 0.2 μm or less, more preferably 0.1 μm or less. Generally, the surface roughness of melt-extruded film is 2-3μ for 100μm thick film.
m, the surface roughness of the cast film is 0.5 to 1 μm for a 100 μm thick film, so the surface roughness of the free surface of the active energy ray-curable resin cured layer (2) is so small that it can be said that it is not common knowledge. Is.

Further, the heat resistance and solvent resistance of the active energy ray-curable resin cured layer (2) of the laminated sheet are improved, and particularly the adhesiveness at the time of forming a transparent electrode is improved, and the air permeation resistance of the layer is improved. The adhesiveness to the resin layer (the surface layer of the optically isotropic sheet (1)) is also excellent.

The laminated sheet of the present invention has an overall retardation value of 6 in consideration of its use in optical applications.
0 nm or less, preferably 30 nm or less, visible light transmittance is 6
It is desired to be 0% or more, preferably 70% or more.

A transparent electrode is provided on the active energy ray-curable resin curable layer (2) of the laminated sheet having the layer structure composed of the optically isotropic sheet (1) / active energy ray curable resin curable layer (2) obtained above. A liquid crystal cell substrate can be manufactured by providing the above structure and further forming an alignment film on it.

For forming the transparent electrode, a vacuum deposition method, a sputtering method, an ion plating method, a metal spraying method, a metal plating method, a chemical vapor deposition method, a spray method or the like is adopted.
The sputtering method is particularly important. As a material of the transparent electrode, a metal such as Sn, In, Ti, Pb, Tb or an oxide thereof is mainly used, and the layer thickness of the transparent electrode is at least 100 angstrom, and further 20
It is usually 0 angstrom or more.

The optical laminated sheet obtained by the method of the present invention is particularly important as an electrode substrate for manufacturing a liquid crystal display panel, and is used for applications such as retardation plate members, polarizing plate members, optical disks and optical cards. Can also be applied.

[0049]

Since the general active energy ray-curable resin has poor adhesion to the air-permeable resin layer, an anchor coating must be applied on the air-permeable resin layer in advance when laminating the resin. In many cases, the adhesiveness is not always sufficient, and there is a disadvantage that usable anchor coating agents are significantly restricted.

However, in the present invention, since the polyisocyanate compound is mixed in the active energy ray-curable resin cured layer (2), the gas permeable resin layer (without the anchor coating layer is formed in advance). The adhesiveness to the surface layer of the optically isotropic sheet (1) is remarkably improved.

In the optical laminated sheet of the present invention, the free surface of the active energy ray-curable resin cured layer (2) located on the surface of the laminated sheet has extremely high surface smoothness. Even when it is used as an electrode substrate of a liquid crystal cell in which liquid crystal is sealed, there is no possibility that the display is colored with colors such as purple and green and the screen becomes very difficult to see.

[0052]

EXAMPLES The present invention will be further described with reference to examples. Hereinafter, “parts” means parts by weight.

Example 1 FIG. 1 is a process chart showing an example of a process for producing an optical laminated sheet of the present invention. FIG. 2 is a cross-sectional view of the optical laminated sheet obtained in Example 1.

In FIG. 1, (5) is a tank, (6) is a jacket, (7) is a lip-shaped discharge port, and (4a) and (4b) are a pair of film-forming rolls. (8) is an ultraviolet irradiation device. (9) is a nip roll, and (10) is a peeling roll for peeling the smoothing template material (3). (S) is an optical laminated sheet.

As an example of the substrate layer, a water-soluble quaternized ester urethane-based anchor coating agent is applied to one side of a polycarbonate sheet (thickness 110 μm, retardation value 12 nm) and dried to form an anchor coating layer 0.5 μm in thickness. After the provision, 20 parts of an ethylene-vinyl alcohol copolymer having an ethylene content of 32 mol%, 45 parts of water, and 5 parts of n-propanol are placed on the anchor coating layer.
A resin solution having a composition of 0 part and 4 parts of methylolated melamine (Sumitec M-3 manufactured by Sumitomo Chemical Co., Ltd.) was cast and passed through a drier at a temperature of 110 ° C. to be dried.
As a result, an air-permeable resin layer having a thickness of 8 μm was formed.

Similarly, an anchor coating layer having a thickness of 0.5 μm is provided on the other surface of the polycarbonate sheet which is the base layer, and the air-permeable resin layer having the same thickness as the above is provided on the anchor coating layer. Was established.

Then, from above the air-permeable resin layer on one side,
Phenoxyether resin (manufactured by Tohto Kasei Co., Ltd.) 40
Part, 40 parts of methyl ethyl ketone, 20 parts of cellosolve acetate, 40 parts of a 75% solution of an adduct of tolylene diisocyanate and trimethylolpropane (Coronate L manufactured by Nippon Polyurethane Co., Ltd.) 40 parts using a curable resin composition using an applicator. And apply it at 80 ℃
Dry for 4 minutes, then heat at 130 ° C for 20 minutes,
A phenoxyether resin-based crosslinkable resin cured product layer having a thickness of 10 μm was formed.

As a result, the optically isotropic sheet (1) having a layer structure of air-permeable resin layer / anchor coating layer / base material layer / anchor coating layer / air-permeable resin layer / crosslinked resin cured material layer is obtained. Was obtained.

Separately, as a smoothing template material (3), a thickness of 50
A biaxially stretched polyethylene terephthalate film (O type, manufactured by Teijin Limited) having a thickness of μm and a surface roughness of 0.04 μm and not subjected to corona discharge treatment was prepared.

100 parts of epoxy acrylic resin "V-2550P" manufactured by Nippon Steel Chemical Co., Ltd., "Coronate 2094" manufactured by Nippon Polyurethane Industry Co., Ltd.
10000cp / 25 ℃) 7 parts, and then benzophenone 0.1
Parts were added and mixed to prepare a resin liquid (2a) of the active energy ray-curable resin composition.

[0061]

[Chemical 3]

The resin liquid (2a) was charged into the tank (5), and a heating medium was sent to the jacket (6) to keep the contents at about 30 ° C. and degassed.

Then, pressure is applied to the upper space of the tank (5),
From the discharge port (7) into the gap between the film forming rolls (4a) and (4b), the resin liquid
(2a) was discharged.

The film-forming rolls (4a) and (4b) are previously supplied with the above-mentioned photoisotropic sheet (1) and smoothing template material (3), respectively, from the discharge port (7). Discharged resin liquid (2a)
Is sandwiched between the air-permeable resin layer surface of the optically isotropic sheet (1) (the surface opposite to the cured crosslinkable resin layer) and the smooth surface of the smoothing template material (3). 2b).

The sandwiching sheet after passing through the film forming rolls (4a) and (4b) was irradiated with ultraviolet rays by the ultraviolet irradiation device (8) under the following conditions, and then the smoothing template material (3) was peeled off. The sandwiching layer (2b) was cured by irradiation with ultraviolet rays to become an active energy ray-curable resin cured layer (2). As a result, an optical laminated sheet (S) having a layer structure of active energy ray-curable resin cured layer (2) / optical isotropic sheet (1) was obtained (see FIG. 2). The removal of the smoothing template material (3) by peeling may be performed once after being once wound on the winder, instead of immediately after the irradiation with ultraviolet rays.

Ultraviolet irradiation conditions Ultraviolet irradiation device UVC-253 manufactured by USHIO INC.
/ 1MNLC3-AA08 lamp High pressure mercury lamp 120W / cm Irradiation distance 200mm Conveyor speed 3m / min

The conditions and results are shown in Table 1. The meanings of the evaluation items are as follows.・ Thickness (2) The thickness is the energy ray curable resin cured layer (2)
Thickness. -Peelability Smoothness of peeling of the biaxially stretched polyethylene terephthalate film as the smoothing template material (3). (○: good, ×: bad) ・ Roughness The surface smoothness of the free surface of the active energy ray-curable resin cured layer (2) was measured by a non-contact surface roughness meter using light interference. -R value The retardation value of the entire optical laminated sheet (S). -Transmittance The visible light transmittance of the optical laminated sheet (S) as a whole. -Hardness Pencil hardness-Solvent resistance The optical laminated sheet (S) was immersed in dimethylacetamide at 44 ± 1 ° C for 5 minutes, and the presence or absence of dissolution of the active energy ray-curable resin cured layer (2) was observed. (○: No abnormality,
X: Melting) -Adhesiveness: Measured based on JIS K5400 cross-cut tape method.

[0068]Table 1 Integrated light intensity (2) Thick peelability Roughness R value Transmittance Hardness Solvent resistance Adhesion  No. (mJ / cm ² ) (μm) (μm) (nm) (%) 1 354 3.8 ○ <0.1 16 88 3H ○ 100/100 2 354 4.3 ○ <0.1 16 88 3H ○ 100/100 3 538 7.0 ○ <0.1 16 87 4H ○ 100/100 4 675 8.0 ○ <0.1 17 87 4H ○ 100/100

Next, the active energy ray-curable resin cured layer of the optical laminated sheet (S) of No. 1 to No. 4 obtained above
A transparent electrode made of an ITO layer having a thickness of 500 Å was directly formed on the surface (2) by a sputtering method. Using this sheet as an electrode substrate, a liquid crystal display panel was produced by forming an alignment film, rubbing, assembling a liquid crystal cell, laminating a retardation plate and a polarizing plate according to a conventional method. The obtained liquid crystal display panel showed no coloring in the display and had a performance comparable to that of a liquid crystal display panel using glass as a substrate.

Example 2 As a base material layer, instead of a polycarbonate sheet, a polyarylate sheet (Kanefuchi Chemical Co., Ltd., thickness 100 μm) was used.
And a retardation value of 15 nm) were used to obtain an optically isotropic sheet (1) in the same manner as in Example 1.

100 parts of phosphazene type curable resin "Idemitsu PPZ" manufactured by Idemitsu Petrochemical Co., Ltd. and 7 parts of "Coronate HX" (mixture of hexamethylene diisocyanate having a polymerization degree of 1 to 3) manufactured by Nippon Polyurethane Industry Co., Ltd. (No. .
5) or 20 parts (No. 6) and 0.2 part of benzophenone were added and mixed to prepare a resin liquid (2a) of the active energy ray-curable resin composition.

The above-mentioned optically isotropic sheet (1) and the resin liquid (2
Example 1 was repeated except that a) was used. The conditions and results are shown in Table 2.

[0073]Table 2 Integrated light intensity (2) Thick peelability Roughness R value Transmittance Hardness Solvent resistance Adhesion No. (mJ / cm ² ) (μm) (μm) (nm) (%) 5 354 3.9 ○ <0.1 20 88 5H ○ ○6 538 6.7 ○ <0.1 19 87 6H ○ ○

Example 3 FIG. 3 is a sectional view of the optical laminated sheet obtained in Example 3.

According to Example 1, a gas-proof resin layer / anchor coating layer / base material layer / anchor coating layer /
An optically isotropic sheet (1) having a layer structure of a gas-proof resin layer was produced.

Using this optically isotropic sheet (1), Example 1
Using the smoothing template material (3) in the same manner as in, but with a 4.0 μm thick active energy ray-curable resin cured layer on one side.
(2) is formed, and the thickness is 4.0μ on the other surface.
An active energy ray-curable resin cured layer (2) of m 2 was formed. However, active energy ray curable resin cured layer (2)
Is an epoxy acrylic resin "V
"2550P" 100 parts 6 parts of "Coronate DC-2977" (hexamethylene diisocyanate low viscosity (100 cp / 25 ° C) aliphatic polyisocyanate) manufactured by Nippon Polyurethane Industry Co., Ltd., which is an example of polyisocyanate compound, and benzophenone 0.2 It was formed by using the resin liquid (2a) of the active energy ray-curable resin composition in which parts were added and mixed.

The surface roughness of the active energy ray-curable resin cured layer (2) of the obtained optical laminated sheet (S) (see FIG. 3) was 0.1 μm or less on both sides, and the active energy ray-curable resin was used. The adhesion between the cured resin layer (2) and the air permeation resistant resin layer of the optically isotropic sheet (1) was also very good.

[0078]

In the optical laminated sheet of the present invention,
Despite the use of the active energy ray-curable resin, the adhesiveness to the air-permeable resin layer (the surface layer of the optically isotropic sheet (1)) is good even if the anchor coating layer is not provided.

In addition, since the optical laminated sheet of the present invention has extremely excellent surface smoothness, even when it is used as an electrode substrate of a liquid crystal cell enclosing STN liquid crystal, for example, a display is obtained. It does not cause a situation where the screen is very difficult to see due to colors such as purple and green.

As the liquid crystal display panel becomes larger year by year,
Although the spread of the STN liquid crystal system is remarkable, the present invention enables display characteristics to be comparable even if a plastics substrate is used instead of the glass substrate for the purpose.

Despite such excellent performance, it has an industrial advantage that its manufacturing process is simple.

[Brief description of drawings]

FIG. 1 is a process drawing showing an example of a manufacturing process of an optical laminated sheet of the present invention.

FIG. 2 is a cross-sectional view of an optical laminated sheet obtained in Example 1.

3 is a cross-sectional view of an optical laminated sheet obtained in Example 3. FIG.

[Explanation of symbols]

 (1) ... Optical isotropic sheet, (2) ... Active energy ray-curable resin cured layer, (2a) ... Resin liquid, (2b) ... Holding layer, (3) ... Smoothing template material, (4a), (4b) ... Film forming roll, (5) ... Tank, (6) ... Jacket, (7) ... Discharge port, (8) ... UV irradiation device, (9) ... Nip roll, (10) ... Peeling roll, (S) ... Laminated sheet for optics

Front page continuation (72) Inventor Tetsunosuke Kobayashi 1-4-6 Nihonbashi-Bakurocho, Chuo-ku, Tokyo Fujimori Industry Co., Ltd.

Claims (3)

[Claims] 1. A layer structure comprising an active energy ray curable resin cured layer (2) containing a polyisocyanate compound, which is provided on a single-layer or multi-layer optically isotropic sheet (1), and An optical laminated sheet having a surface roughness of 0.5 μm or less on the free surface of the active energy ray-curable resin cured layer (2), a retardation value of the entire laminated sheet of 60 nm or less, and a visible light transmittance of 60% or more. 2. An active energy ray-curable resin cured layer (2) containing a polyisocyanate compound on a single-layer or multi-layer optically isotropic sheet (1) having at least a surface layer of a gas-proof resin layer. The laminated sheet for optics according to claim 1, which has a layer structure provided with. 3. An active energy ray-curable resin composition containing a polyisocyanate compound in the gap between a single-layer or multi-layered optically isotropic sheet (1) and a smoothing template material (3) having a smooth surface. The resin liquid (2a) is supplied so that the resin liquid (2a) is sandwiched between the two layers, and then the sandwiching layer (2b) is cured by irradiation with active energy rays to cure the active energy ray. A method for producing an optical laminated sheet, which comprises forming a cured resin layer (2).