JPH06347774A - Electrode film for liquid crystal display panel - Google Patents

Abstract

PURPOSE:To provide an electrode film for a liquid crystal display panel excellent in chemical resistance. CONSTITUTION:This electrode film for a liquid crystal display panel consists of a protective layer, base film (except acetylcellulose resin), protective layer, and transparent conductive layer. At least one of protective layers is an org. resin layer containing a resin layer having urethane bonds. The other protective layer may be another org. resin layer or inorg. protective layer.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an electrode film for a liquid crystal display panel, and more particularly to an electrode film for a liquid crystal display panel using an organic film as a base film.

[0002]

2. Description of the Related Art An electrode used in a liquid crystal display panel is well known in which a layer of an In ₂ O ₃ -SnO ₂ compound (hereinafter referred to as ITO) is provided on a glass substrate. . However, an electrode using such a glass substrate has problems of weak impact resistance during transport and weight increase due to an increase in size of a display panel, and thus improvement has been demanded. Therefore, an organic film substrate (base film) is used as a substitute for the glass substrate, and a substrate on which an ITO film is formed has been proposed.

However, such a base film does not have the transparency and polarization characteristics of glass, and I
Properties such as chemical resistance associated with TO patterning are required, but a base film that can sufficiently satisfy these required properties has not yet been known.

Therefore, an object of the present invention is to provide an electrode film for a liquid crystal display panel which is excellent in protection characteristics, particularly chemical resistance.

[0005]

The present invention provides an electrode film for a liquid crystal display panel in which at least a transparent conductive layer is provided on an optically isotropic transparent base film, the base film being an organic film excluding acetyl cellulose resin. A resin film, and a protective layer is provided on both sides of the base film, at least one of the protective layers is an organic resin layer containing a resin layer having a urethane bond, and one side of the protective layer is further provided. The present invention provides an electrode film having a transparent conductive layer provided thereon.

The optically isotropic transparent base film used in the present invention is an organic resin film excluding acetyl cellulose resin, and examples thereof include films of polycarbonate, polyarylate, amorphous polyolefin, polyether sulfone and polysulfone. These may be used alone or in combination of two or more. The thickness of the film is preferably 55 to 5000 μm.

In the present invention, protective layers are provided on both sides of the base film, and at least one side of the protective layer is an organic resin layer containing a resin layer having a urethane bond. By using such a protective layer, an excellent chemical resistance effect could be obtained. Here, the resin having a urethane bond means a resin obtained by reacting one or more compounds having an isocyanate group with a polyol compound. Examples of the compound having an isocyanate group include diisocyanate compounds such as toluene diisocyanate, diphenylmethane diisocyanate, and dimethyldiphenyl diisocyanate, and modified isocyanate compounds obtained by chemically modifying these compounds. As the polyol compound, for example, ethylene glycol, propylene glycol, glycerin, pentaerythritol, low molecular weight polyols such as sorbitol and high molecular weight polyols starting from these polyols, for example, polyether-based polyols, polyester-based polyols, Polyether ester-based polyols and modified products thereof such as acrylic acid-modified polyols and epoxy-modified polyols may be used, and are not particularly limited.

The organic resin layer may be a mixture of the above-mentioned resin having a urethane bond with other resins, and may have a multi-layer structure. Examples of such other resins include epoxy resins, acrylic resins, polyester resins, polyamide resins, phenol resins, silicone resins, ethylene-vinyl alcohol copolymers, acrylonitrile-butadiene resins (for example, ABS resin), vinyl chloride-vinyl acetate copolymer, and the like. These can be used alone or in combination of two or more.

When the protective layer is not an organic resin layer containing the above-mentioned resin layer having a urethane bond, the protective layer may be another organic resin layer or an inorganic protective layer. In the case of another organic resin layer, one or more of the above resins can be used.

When the protective layer is an organic resin layer, the thickness of the protective layer is preferably in the range of 1 to 20 μm. The organic resin layer can be provided by a conventional means such as gravure coating. In the case of an organic resin layer including a resin layer having a urethane bond, for example, a raw material, that is, a mixture of a compound having an isocyanate group and a polyol can be applied by gravure coating or the like.

When an inorganic protective layer is used as the protective layer, the inorganic material used in such an inorganic protective layer is at least one compound selected from silicon compounds, titanium compounds and aluminum compounds. Is preferred. As the silicon compound, for example, SiO
_x (x = 1.3 to 2.0 is preferred), silicon oxide represented by, for example, SiN _x, silicon nitride represented by (x = 1.1 to 1.5 is preferred), silicon nitride oxide (e.g., SiN
_x O _y (x = 1.0 to 1.4, y = 1.1 to 1.9 are preferred)
Etc.), silicon carbide (SiC), and the like. Examples of titanium compounds include TiO ₂ and TiC. As the aluminum compound, for example, AlO
_x (preferably x = 1.1 to 1.8), AlN _x (x = 0.8
To 1.6) are preferable. The inorganic protective layer is
It can be provided by a known film forming method, for example, a vapor deposition method, a sputtering method, an ion plating method, a CVD method, a spray method or the like. The layer thickness of the inorganic protective layer is 200 to 4000.
The Angstrom range is preferred. The inorganic protective layer does not necessarily have to be a single layer, and may be a laminated body of two or more layers.

The transparent conductive layer is provided on the above-mentioned protective layer (on one side). As the transparent conductive layer, a conventional transparent conductive layer material, for example, a metal oxide can be used.
Specifically, for example, SnO ₂ , CdO, ZnO, CTO system (CdSnO ₃ , Cd ₂ SnO ₄ , CdSnO ₄ ), I
Examples include n ₂ O ₃ and CdIn ₂ O ₄ . It is preferably a composite (doped) phase in which one or more selected from Sn, Sb, F and Al are added to the above metal oxide. Among them, the preferable one is Sn-added I
Examples include n ₂ O ₃ (ITO), Sb-added SnO ₂ , F-added SnO _{2, and the} like. As the transparent conductive layer, these layers can be used as a single layer or multiple layers. Although the layer thickness varies depending on the material, for example, the ITO layer has a thickness of 200 to 3500.
Angstrom is preferable, and 300 to 300 is particularly preferable.
It is 3100 angstroms. The sheet resistance of the transparent conductive layer is not particularly limited as long as it is 400Ω / □ or less.
The transparent conductive layer can be provided by a known film forming method, for example, a vapor deposition method, a sputtering method, an ion plating method, a CVD method, a spray method or the like.

The electrode film of the present invention has a constitution of protective layer / base film / protective layer / transparent conductive layer. The protective layer does not have to be one layer, and another protective layer can be provided as a base layer for one protective layer. Also,
The organic resin layer and the inorganic protective layer may be used in combination. That is, the electrode film of the present invention can have, for example, the following constitutions: organic resin layer / base film / inorganic protective layer / transparent conductive layer, organic resin layer / inorganic protective layer / base film / inorganic protective layer. / Transparent conductive layer,
Inorganic protective layer / organic resin layer / base film / inorganic protective layer / transparent conductive layer, inorganic protective layer / base film / organic resin layer / transparent conductive layer, inorganic protective layer / base film / inorganic protective layer / organic resin layer / transparent Conductive layer, inorganic protective layer / base film / organic resin layer / inorganic protective layer / transparent conductive layer, organic resin layer / inorganic protective layer / base film /
Organic resin layer / transparent conductive layer, organic resin layer / base film / inorganic protective layer / organic resin layer / transparent conductive layer, organic resin layer / base film / organic resin layer / inorganic protective layer / transparent conductive layer, inorganic protective layer / Organic resin layer / base film / organic resin layer / transparent conductive layer, inorganic protective layer / organic resin layer / base film / organic resin layer / inorganic protective layer / transparent conductive layer, organic resin layer / inorganic protective layer / base film / inorganic material Protective layer / organic resin layer / transparent conductive layer.

In the above embodiment, at least one of the organic resin layers is a layer containing a resin having a urethane bond. When there are two or more organic resin layers or inorganic protective layers, they may be the same or different.

The electrode film for a liquid crystal display panel of the present invention thus obtained has an overall visible light transmittance of 80.
% Or more, and the deterioration of the transmittance due to layer formation may be 8% or less as compared with the base film.

[0016]

The present invention will be described in more detail by the following examples. Example 1 On both sides of a polyarylate film having a thickness of 100 μm,
6 parts by weight of an ethyl acetate solution containing 75% by volume of toluene diisocyanate (TDI) and an acrylic acid-modified polyol solution containing nitrified cotton (acrylic acid-modified polyol 3
1% by volume content, trade name: UM-AL medium, manufactured by Dainichiseika Co., Ltd.) 100 parts by weight of a coating solution was mixed by gravure coating to a thickness of 5 μm. Next, an ITO layer having a thickness of 1000 angstrom was formed on this one surface by a sputtering method. That is, a powder sintered body of In ₂ O ₃ and SnO ₂ (weight ratio 90:10) is used as a target, and a mixed gas of argon and oxygen (Ar / O ₂ = 90/10; volume ratio) is used as a reaction gas. did.

Thus, the organic resin layer / base film /
An electrode film having a structure of organic resin layer / ITO layer was obtained. With respect to this, the following chemical resistance test was conducted.
The test results are shown in Table 1. (1) Acid resistance test: It was immersed in a 50 ° C.-10% HCl aqueous solution for 30 minutes and then dried with hot air. (2) Solvent resistance test: Dipped in acetone for 30 minutes and dried with hot air. (3) Alkali resistance test: 50 ° C-20% NaOH aqueous solution was immersed for 30 minutes and then dried with hot air. Example 2 On one side of a polyarylate film having a thickness of 100 μm,
15 parts by weight of an ethyl acetate solution containing 75% by volume of TDI used in Example 1 was mixed with an epoxy-modified polyol (trade name:
EP-6027, manufactured by Asahi Denka Co., Ltd.) 100 parts by weight of a mixed solution of 25% by volume, 50% by volume of ethyl acetate, 15% by volume of toluene and 10% by volume of methyl ethyl ketone was added and mixed to obtain a coating solution having a thickness of 4 μm by gravure coating. It was applied so that Next, the surface of the base film opposite to the organic resin layer was applied with an ion plating method to form 12
The SiO ₂ layer was formed to a thickness of 00 Å. An ITO layer having a thickness of 1000 Å was continuously formed on this SiO ₂ layer by a sputtering method. The sputtering conditions were the same as in Example 1.

About the obtained electrode film (organic resin layer / base film / SiO ₂ layer / ITO layer) Example 1
A chemical resistance test was conducted under the same conditions as above. The results are shown in Table 1. Comparative Example 1 On one side of a polyarylate film having a thickness of 100 μm,
Organic resin A resin layer is not provided, and the sputtering method is directly applied to Example 1.
ITO with a thickness of 1000 angstrom
Layers were formed.

The resulting electrode film (base film /
A chemical resistance test was performed on the ITO layer) under the same conditions as in Example 1. The results are shown in Table 1.

[0020]

[Table 1] Table 1 ----------------------------------- Chemical resistance test Example 1 Example 2 Comparative Example 1 --- −−−−−−−−−−−−−−−−−−−−−−−−−−− Acid resistance test No change No change No change Solvent resistance test No change No change White turbidity alkali test No change No change Some White turbidity ------------------------------------- When the above-mentioned electrode film was incorporated into a liquid crystal display panel, it was found that the action as an electrode film There was no problem.

[0021]

The electrode film for a liquid crystal display panel of the present invention is excellent in chemical resistance, has a long panel life and is industrially useful.

Claims (1)

[Claims] 1. An electrode film for a liquid crystal display panel, wherein at least a transparent conductive layer is provided on an optically isotropic transparent base film, wherein the base film is an organic resin film excluding acetyl cellulose resin, and A protective layer is provided on both surfaces of the film, at least one of the protective layers is an organic resin layer containing a resin layer having a urethane bond, and a transparent conductive layer is further provided on one surface of the protective layer. An electrode film characterized in that