JPH06235813A - Production of color filter - Google Patents

Abstract

PURPOSE:To easily and stably obtain desired low-density spectral characteristics by exposing and developing a color filter pattern, heating the resin remaining, and then dyeing. CONSTITUTION:A photosensitive resin which can be dyed with a dye is applied on a substrate, exposed and developed to obtain a color filter pattern, and then the resin remaining is dyed with a dye to produce a color filter. In this method, the remaining resin after exposure and development to form the color filter pattern is heat treated and then dyed. Namely, the photosensitive resin layer after formed is exposed through a mask so that only the area for the color filter pattern of the first color is hardened with light. Then the resin is developed to remove the photosensitive resin except for the first color pattern. Then prior to dyeing, the resin is heat treated. By this method, the dyeing rate in the successive dyeing process can be decreased so that the dyeing time can be controlled. Thus, desired spectral characteristics shown as figure can be stably obtd. The dyeing temp. is generally about 50-70 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dyeing type color filter used in a color image pickup device such as an image pickup tube or a CCD, or a color liquid crystal display device. In addition, the present invention relates to a method for producing a color filter which can be stably obtained.

[0002]

2. Description of the Related Art A conventional color filter is a photosensitive film formed by coating a glass substrate with a sensitizing liquid such as gelatin, which is dried, and exposing it to a color filter pattern to develop it. It is manufactured by repeating the steps of dyeing with, and then performing post-treatments such as washing with water, fixing and fixing, for the number of colors.

[0003]

In such a dyeing type color filter, a dye which is bright and has a strong light absorbing property is generally selectively used. When dyed with such a dye, it takes a relatively short time. A saturated dyeing state is reached in the dyeing time.

However, recently, in addition to the conventional transmissive color liquid crystal display device, a reflective liquid crystal display device has been widely used. In this case, it is particularly desired that the desired spectral characteristics be dyed lightly and stably.

Conventionally, in the case of dyeing a lightly set dyeing density, the dyeing time is usually shortened,
Alternatively, a method such as lowering the dyeing temperature may be used, but it has a drawback that it becomes unstable in the process and it is difficult to stably obtain desired spectral characteristics.

As another method for lightly dyeing, there is also a method in which the film thickness of the photosensitive film is greatly reduced or the dye concentration of the dyeing solution used is greatly reduced, but the former has a problem in yield. However, there is a drawback that the productivity is lowered, and the latter has a drawback that the dyeability is easily changed due to the change of the dye concentration, and the maintenance of the dyeing bath is extremely difficult.

Further, when lightly dyed by such a conventional method, there is a problem that a change in spectral characteristics due to decolorization in a post-treatment step becomes large.

The present invention has been made in view of the above conventional problems, and an object thereof is to provide a method of manufacturing a color filter which can easily and stably obtain a desired low-density spectral characteristic.

[0009]

In order to achieve the above object, the present invention provides the above resin which remains after a photosensitive resin dyeable by a dye is applied on a substrate, exposed to a color filter pattern and developed. In the method for producing a color filter obtained by dyeing with a dye, the resin remaining after exposing and developing the color filter pattern is heat-treated and then dyed.

The structure of the present invention will be described in more detail below.

FIG. 1 is a sectional view showing an example of a reflection type color liquid crystal display device. According to this, an Al layer 2, a liquid crystal layer 3 and a transparent electrode ITO 4 are provided between two glass plates 1 and 6.
Also, the color filter layer 5 is incorporated.

Since the color filter manufactured by the present invention can stably obtain desired low-density spectral characteristics, it is particularly suitable for use as a color filter incorporated in the above reflective color liquid crystal display device.

The method for producing a color filter of the present invention comprises:
Basically, coating / drying (pre-baking) of photosensitive resin
It consists of repeating a series of processes consisting of exposure, development, heat treatment, dyeing, and post-treatment for the number of colors.

As the photosensitive resin, for example, polyvinyl alcohol, glue, gelatin or the like to which photosensitivity is imparted is used. This photosensitive resin is uniformly applied onto a glass substrate that has been optically polished by a method such as whiler, roller coating, or dipping. The coating thickness of the photosensitive resin is generally about 0.5 to 2.0 μm.

The photosensitive resin coated on the glass substrate is prebaked and dried at a temperature that does not affect the photosensitivity.

Next, the formed photosensitive resin layer is subjected to mask exposure to photo-cure only the color filter pattern portion of the first color, and this is developed to remove the photosensitive resin other than the pattern portion of the first color.

Next, according to the present invention, heat treatment is carried out before starting the dyeing step. By performing the heat treatment before the dyeing step, the dyeing speed in the next dyeing step can be slowed down. The heat treatment temperature is optional, but if you want to obtain a slightly faint spectral characteristic in the next dyeing process, 140 ℃ to 170 ℃
A temperature range of about ℃ is desirable, while a temperature range of about 180 ℃ to 220 ℃ is desirable for obtaining fairly light spectral characteristics. Also, although the heat treatment time is arbitrary,
It is preferably 30 to 120 minutes. As the heat treatment means,
For example, it is easy to use a hot oven or a hot plate.

After the above heat treatment, the dyeing step is started. The remaining resin is dyed with a dye having a predetermined spectral characteristic. In the present invention, as described above, by performing the heat treatment before the dyeing step, the dyeing speed can be moderated and the time scale until the saturated dyeing state can be set to be relatively long, so that the dyeing time is adjusted. By doing so, desired spectral characteristics can be stably obtained. The composition of the dyeing solution to be used, the dye concentration and the like are the same as those conventionally used and there is no particular limitation. The dyeing temperature is generally about 50 to 70 ° C.

After the dyeing, post-treatments such as washing with water, fixing and fixing are carried out. In this way, the first color filter section is completed.

For example, in the case of a three-color filter, by repeating the same steps as above,
The filter parts for the third and third colors are sequentially formed. In the present invention, the number of colors of filters is not limited, and filters of any colors can be manufactured. In addition, an intermediate layer or a top coat made of a material that is optically transparent and does not affect the spectral characteristics of the filter so as to prevent the filter portion of the already formed hue from being dyed when dyeing the second and subsequent colors. You may make it provide a layer. Further, in order to improve the display quality of the liquid crystal display device, a light-shielding black matrix pattern may be provided at the boundary between the filter patterns of each color. This black matrix pattern can also be formed by forming a relief pattern in the same manner as other color filter parts and dyeing it with a black dye, or by providing an opaque metal pattern.

[0021]

According to the present invention, after the photosensitive resin layer coated on the glass substrate is exposed and developed into a color filter pattern, the remaining resin is heat treated and then dyed. In this way, by performing the heat treatment before the dyeing process, the dyeing speed in the next dyeing process is made gentle, and the desired spectral characteristics are dyed lightly and stably, so that the desired low-density spectral characteristics are obtained. can get.

[0022]

EXAMPLES The present invention will be described in more detail below with reference to examples.

On a glass substrate that has been subjected to optical polishing, a photosensitive liquid that imparts sensitivity to gelatin is uniformly applied by roller coating and dried to form a gelatin photosensitive film, and then a first color red stripe pattern is formed by a mask exposure method. Expose the
Developed. After development, heat treatment was carried out by leaving it in an oven at 200 ° C for 1 hour, and then the remaining stripe pattern gelatin film was dyed at 65 ° C with the following red dyeing solution and then washed with water, each at 70 ° C. The dye was fixed and fixed by immersing it in the tannic acid aqueous solution and the tartaric acid aqueous solution for 1 minute each.

Next, in the same manner, the above-mentioned gelatin photosensitive solution was uniformly applied again to form a photosensitive film, which was then exposed by a mask exposure method and developed to form a second color green stripe pattern. After heat treatment at 200 ° C. for 1 hour in the same manner as described above, the second color stripe pattern portion was dyed with the following green dyeing solution at 65 ° C., and then washed with water and the fixing / fixing treatment was performed. .

Further, in the same manner, the above-mentioned gelatin photosensitive solution is applied again and again to form a photosensitive film, which is then exposed by a mask exposure method and developed to form a blue stripe pattern of the third color, and 200 ° C. for 1 hour. After the heat treatment of 1., the stripe pattern portion of the third color was dyed with the following blue dyeing solution at 65 ° C. Then, washing with water and the fixing / fixing treatment were performed to form a thermosetting acrylic resin layer as a top coat layer to obtain three color filters of red, green and blue.

The composition of the dyeing solution used and the dyeing time are shown below. (A) Compounded red diaside fast rubinol 3G (manufactured by Mitsubishi Kasei Co., Ltd.) 5 g Kayanol orange G (manufactured by Nippon Kayaku Co., Ltd.) 3 g Acetic acid 5 cc Water 1000 cc Green patent green (manufactured by Tokyo Kasei KK) ) 3 g Chrysophenone (Tokyo Kasei Co., Ltd.) 5 g Kayanor Milling Yellow 5 GW (Nippon Kayaku Co., Ltd.) 2 g Acetic acid 5 cc Water 1000 cc Blue Solophenol Turkis Blue BRL (Ciba Geigy) 10 g Kaya Nolusianin G (manufactured by Nippon Kayaku Co., Ltd.) 1 g Acetic acid 2cc Water 1000cc (b) Dyeing time Red 1-8 minutes Green 1-8 minutes Blue 0.5-5 minutes

On the other hand, in the production of the above color filter, a color filter produced in exactly the same manner except that the heat treatment before the dyeing step was not performed was compared.

FIG. 2 shows the spectral characteristics of each color when the dyeing time was changed for each of the color filter obtained by the manufacturing method of the present invention and the color filter for comparison.
(Red, Red), FIG. 3 (Green, Green) and FIG. 4 (Blue, Blue). In each figure, (a) shows a color filter obtained by the present invention in which heat treatment is performed before dyeing, and (b) shows a color filter for comparison obtained by a conventional method in which heat treatment before dyeing is not performed. .

FIG. 5 shows how the transmittance at the maximum absorption wavelength of each color changes with the dyeing time when the heat treatment temperature before dyeing is changed in the present invention.

As is clear from the results shown in FIGS. 2 to 4 and 5, it is understood that according to the present invention, a desired light low concentration spectral characteristic can be obtained.

FIG. 6 shows the decolorizing properties before and after fixing / fixing. By performing heat treatment before dyeing, even if dyeing lightly, decolorization of the dye after washing and fixing / fixing treatment after dyeing. Can be prevented. The effect is particularly high when the heat treatment temperature is 140 ° C or higher.

Further, FIG. 7 shows the result of the heat resistance test at 200 ° C. for 1 hour, and it is understood that the heat resistance of the color filter thus produced is improved by performing the heat treatment before dyeing. The effect is particularly high when the heat treatment temperature is 140 ° C or higher.

[0033]

As described in detail above, according to the present invention, after the photosensitive resin layer coated on the glass substrate is exposed and developed into a color filter pattern, the remaining resin is heat treated and then dyed. Since it is carried out, there is an excellent effect that the desired lightly dyed low-density spectral characteristic can be easily and stably obtained.

Further, according to the present invention, it is possible to prevent the decolorization of the dye in the post-treatment step after dyeing, and further improve the heat resistance of the color filter thus formed.

Further, the present invention is an extremely economical and simple method since it can be carried out by using conventional equipment as it is by simply adding a heating means such as an oven.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a reflective color liquid crystal display device.

FIG. 2 is a diagram showing spectral characteristics of a red portion of a color filter manufactured by the method of the present invention and the conventional method.

FIG. 3 is a diagram showing spectral characteristics of a green portion of a color filter manufactured by the method of the present invention and the conventional method.

FIG. 4 is a diagram showing spectral characteristics of a blue portion of a color filter manufactured by the method of the present invention and the conventional method.

FIG. 5 is a diagram showing changes in transmittance at the maximum absorption wavelength of each color when the heat treatment temperature before dyeing is changed.

FIG. 6 is a diagram showing results of decolorizing properties before and after fixing and fixing.

FIG. 7 is a diagram showing a result of a heat resistance test.

[Explanation of symbols]

 1 glass plate 2 Al layer 3 liquid crystal layer 4 transparent electrode ITO 5 color filter layer 6 glass plate

Claims (1)

[Claims] 1. A method for producing a color filter, comprising the steps of applying a photosensitive resin dyeable with a dye onto a substrate, exposing the resin to a color filter pattern, developing the resin, and dyeing the remaining resin with the dye. A method for producing a color filter, which comprises subjecting a resin remaining after exposure and development to a filter pattern to heat treatment, and then dyeing.