JPS6169004A - Color filter - Google Patents

Abstract

PURPOSE:To obtain a color filter having superior performance such as heat and water resistances, a clear pattern edge and a smooth surface by forming an active film on a transparent substrate and filling a dye into micropores in the active film to carry out coloring or pattern formation. CONSTITUTION:An active film 2 of activated alumina and/or activated silica is formed on a transparent substrate 1, and a dye 4 is filled into micropores 3 in the active film 2 to carry out coloring or pattern formation. An overcoat layer 5 is then formed on the active film 2 to seal the micropores 3.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a color filter for various display devices, and more specifically, it enables color display by applying it to various display devices. The invention relates to color filters.

[Prior art and its problems]

There are various types of color filters for display devices.
A color filter for a liquid crystal display device will be explained below as a representative example.

Liquid crystal display devices are used for digital display of calculators and electronic clocks,
It is widely used for analog display of measuring and instrumentation equipment, home appliances, and audio equipment.

Recently, there has been an increasing demand for color display of liquid crystal display devices, mainly for peripheral terminal displays of various devices, in-vehicle displays, telephone displays, and television image displays. In order to meet this demand, various color liquid crystal display devices have been proposed, some of which are already being put into practical use. However, none of the currently proposed color display systems for liquid crystal display devices fully satisfies the needs of those who use them.

Conventionally, color filters applied to liquid crystal display devices capable of color display include: 1. A gelatin layer is formed on the inner surface of a transparent substrate, and this gelatin layer is dyed. There are products in which a resin layer that can be dyed is formed on the resin layer, and this resin layer is dyed.

However, all of these have the following drawbacks. That is, the color filter (2) has no heat resistance (Al).Therefore, it has the disadvantage that the color filter cracks due to heating when forming a transparent conductive film on the color filter using the thin coating method. In order to avoid this, when vapor deposition is carried out at a low temperature, the resistance value of the transparent 4-electrode film becomes large and the light transmittance becomes low.

(b) No water resistance. Therefore, cleaning with an aqueous solution is difficult, and the display quality of the liquid crystal is degraded due to dirt.

The color filter (a) has no heat resistance. Therefore, there are the same drawbacks as shown in ■-(al).Furthermore, if the heating temperature when forming the transparent conductive film is too high, there are problems such as decomposition, coloring, and melting of the resin. Even within the temperature range, the dye that has been dyed in a specific pattern is transferred to unnecessary areas due to heat, resulting in color mixing, which is the so-called bleed problem.

[Object of the present invention]

An object of the present invention is to provide a color filter that has excellent properties such as heat resistance and water resistance, and has clear pattern edges.

[Structure of the invention]

In view of the various drawbacks mentioned above, the inventors of the present invention attempted to obtain a color filter that could eliminate all of the above-mentioned drawbacks, and as a result of intensive research and experiments, they completed the seventh invention. . That is, in the present invention, an active film layer made of at least one of activated alumina or activated silica is formed on a transparent substrate, and a dye is dyed into the fine pores of the active film layer to form a color or a pattern. is formed,
The color filter is further characterized in that a coating layer for sealing the micropores is formed above the micropores of the active film layer.

Hereinafter, the color filter of the present invention will be explained in detail based on the drawings.

The transparent substrate used in the present invention may be one commonly used in liquid crystal display devices, and it is usually preferable to use a glass substrate.

On this transparent substrate, an active film layer consisting of one or more layers of activated alumina or activated silica is formed.

To form this active film layer, first, colloidal alumina, colloidal silica, or a mixture of both is coated on the surface of a transparent substrate, and after drying, for example, 1
What is necessary is just to bake for 0 minutes - 180 minutes. The active membrane layer obtained in this way is transparent and has many fine pores formed therein, and becomes a dyed layer. Note that the active film layer has a thickness of 1 μm to 1 μm, considering its transparency, surface hardness, dye receptivity, etc.
Layer thicknesses of 0 μm, preferably 2 μm to 5 μm are desirable. This is because when the active film layer becomes thick, it tends to whiten and become opaque, and on the other hand, when the active film layer becomes thin, the dyeing density cannot be obtained.

The active membrane layer is colored or patterned by dyeing the fine pores of the active membrane layer. Dyes that can be used in the present invention include sublimable dyes and/or
There are also dyes that melt and vaporize under heat. Specifically, the Kayaset series (manufactured by Nippon Kayaku Co., Ltd.), the oil color series (manufactured by Orient Chemical Co., Ltd.), and the oleosol series (manufactured by Sumitomo Chemical Co., Ltd.)
, etc.

In order to dye using the dye, an ink containing the dye is used at a temperature such that the dye is thermally transferred into the micropores, although this differs depending on the type of dye.
For example, it may be heated at 100° C. to 250° C. for several seconds to 60 minutes.

Note that methods for forming the dye on the active layer include, for example, (1) metal mask method, (2) intaglio sublimation method, (3) sublimation transfer method, and (4) patterning of the active film layer. (5) A method of heating and dyeing only the necessary parts, (
6) Denoping method, (7) Spray method, (8) Direct printing method, (9) Coating method, (10) Hand-painting method, (11) Resist method, (12) Decolorization method, etc. Among these, in the case of uniform coloring on the entire surface, (6), (7), (9), and in the case of patterned coloring, (1), (2), (3), (5)
), etc. are suitable.

The pattern on which the dye is dyed may be designed as appropriate depending on the application, but the color filter according to the present invention can be easily formed even in a shape like a tondo pattern. In this case, the pattern formed by dyeing is a pattern consisting of two or more colors, and the transparent conductive film formed on the coating layer is composed of a pattern corresponding to the pattern of each of the above-mentioned colors, The pattern and the corresponding transparent conductive film pattern are formed at exactly the same position.

A coating layer for sealing the micropores is formed above the micropores of the active membrane layer dyed with the dye. This coating layer can be made of acrylic, melamine, epoxy,
It is obtained by applying a hard and transparent resin such as a silicone polymer or polyimide onto the micropores of the active film layer, and then heating the resin at a temperature that hardens the resin. In addition, it can also be obtained by coating and heating an inorganic material such as sodium silicate or lithium silicate. The reason for providing this coating layer is to prevent the dye molecules trapped in the micropores of the active membrane layer from being vaporized again and to prevent contamination by unnecessary substances.

In addition, when forming this coat layer, when covering the color filter obtained by the present invention with a transparent conductive film exhibiting a desired pattern in a post-process, the coat layer has excellent adhesion to the substance constituting the transparent conductive film. This is extremely suitable as it greatly contributes to improving the adhesion between the color filter and the transparent conductive film.

The color filter for liquid crystal display according to the present invention has the above-mentioned configuration, and in use, a transparent conductive film is provided on the color filter as appropriate, an alignment film is provided as necessary, and a corresponding transparent conductive film is provided on the color filter. It is preferable to have a structure in which liquid crystal is sealed between the substrate and the liquid crystal is further sandwiched between two polarizing plates. However, this structure is an example of a liquid crystal display device, and the structure is not limited to this.

〔Effect of the invention〕

Since the color filter according to the present invention has the above configuration, it has the following effects. In other words, since an active film layer made of activated alumina or activated silica is formed on a transparent substrate, it has extremely superior properties such as heat resistance and water resistance compared to conventional color filters. It also has excellent chemical resistance and solvent resistance. Further, since the dye for coloring or forming a pattern is dyed into each independent micropore of the active film layer, there is no problem such as bleeding.

Further, dyes that require relatively high temperatures and long periods of time to be colored can also be used, which widens the range of dye selections. Furthermore, a simple method can be used for patterning.

Therefore, the present invention has extremely high industrial utility value.

Claims (6)

[Claims] (1) An active film layer made of at least one of activated alumina or activated silica is formed on a transparent substrate, and a color or pattern is formed by dyeing the micropores of the active film layer. A color filter further comprising a coating layer formed above the micropores of the active film layer for sealing the micropores. (2) The color filter according to claim 1, wherein the active film layer has a thickness of 1 μm to 10 μm. (3) The dye in the micropores of the active membrane layer is a sublimable dye or/
The color filter according to claim 1, wherein the color filter is a dye that is thermally melted and vaporized. (4) The color filter according to claim 1, wherein the coating layer is covered with a transparent conductive film exhibiting a desired pattern. (5) The pattern formed by dyeing is a pattern consisting of two or more colors, and the transparent conductive film is composed of a pattern corresponding to the pattern of each color,
5. The color filter according to claim 4, wherein the patterns of each color and the corresponding transparent conductive film patterns are formed at exactly matching positions. (6) The color filter according to claim 4 or 5, wherein the coating layer is formed using a resin that has excellent adhesion to the substance constituting the transparent conductive film. .