JPS606904A - Color filter manufacturing method - Google Patents

Abstract

PURPOSE:To obtain a filter with superior dyeability while easily controlling the thickness by coating an aqueous photosensitive liq. contg. low molecular gelatin obtd. by decomposing high molecular gelatin on a substrate and by subjecting the resulting film to imagewise exposure, development, burning and coloring with an acid dye. CONSTITUTION:A photosensitive liq. is prepd. by adding a photopolymn. initiator such as ammonium dichromate and an auxiliary such as alcohol, chrome alum or balsamic tincture to an aqueous soln. of gelatin with 5,000-70,000 average mol. wt. obtd. by thermally decomposing acid-treated high molecular gelatin. The photosensitive liq. is coated on a glass substrate and prebaked. The resulting film is exposed to ultraviolet rays through a photomask, and it is devloped with cold water, burned at about 150 deg.C, and dyed with an acid dye. The development is finished within about 3min. Since the photosensitive liq. does not gel at room temp., the thickness of the film is easily controlled, and much residual NH2 in the gelatin facilitates the dyeing of the film, so a color filter giving a fine pattern with high reproducibility is obtd. with high productivity.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a color filter.

Conventionally, water-soluble photosensitive substances for coloring base materials in the production of color fills include hydrophilic resins such as egg white, glycou, casein, polyvinyl alcohol, and gelatin, as well as photosensitive agents (
As a photopolymerization initiator, dichromate, chromate, or diazo compound is added, and all of them are negative type.

The following process (Japanese Patent Publication No. 62-17376, Japanese Patent Publication No. 52-17376 Mei #1, etc.) is used as a method for producing color fill.

Namely, ■ Adjustment of photosensitive liquid base, ■ Addition of photosensitive main agent, ■ Coating onto substrate, ■ Prebaking, ■ Mask exposure, ■ Hot or cold water phenomenon, ■ Burning, ■
Each step of dyeing (usually with acid dyes) is carried out in sequence.

Note that since the pot life of the photosensitive solution is short, the photosensitive main agent is generally added immediately before use.

However, in the conventional gelatin photosensitive solution for producing color fill, the main ingredient gelatin is polymeric gelatin with a molecular weight of 150,000 to 250,000 (for photographic use) obtained by treating cow bones with lime and then extracting them with hot water. gelatin, general industrial gelatin, edible gelatin, etc.), most of the amides in gelatin are converted to carboxy) V groups during the lime treatment process, etc. LL score was low. In other words, in conventional photosensitive solutions using lime-treated gelatin, there are few staining sites (i.e., amino groups) caused by acid dyes, and therefore, in order to obtain the dyeing density necessary for a color filter, a coating film of about 2 to 3 μm is required. It needs thickness. However, in recent years, with the increasing precision of color mosaic filters for solid-state image sensors,
There has been a demand for manufacturing a mosaic filter with a pattern size of about 6 μm, but sufficient pattern accuracy could not be obtained with a coating film thickness of 2 to 3 μm.

On the other hand, since the molecular weight of seratin is as high as 150,000 to 260,000, when the gelatin concentration is 10 to 20%, it almost gels at 30 to 4°C. It does not gel at about 25°C ± 5°C.)

Therefore, if the gelatin photosensitive solution is applied at 25±5°C, so-called room temperature, gelation may occur during coating, even if the photosensitive solution is preheated to 25°C, making it impossible to apply the film smoothly or making the film thicker. It was also very difficult to control. Therefore, coating work is generally carried out at a constant temperature of 40 to 45 degrees Celsius, but considering the operation of a constant temperature room of 40 to 45 degrees Celsius and the rationalization of the coating process, ceratin, which does not gel even near room temperature, has been developed. A method using a photosensitive liquid based on photosensitive materials has been eagerly awaited.

The present invention has been made in view of the above-mentioned drawbacks of color fill production using gelatin-based photosensitive liquids, and its purpose is to provide gelatin-based photosensitive liquids that are easy to dye.
In other words, there are many amino groups in the molecule, and the temperature at room temperature (25±
The purpose of the present invention is to provide a method for producing a color filter using a photosensitive material for producing a color filter that does not gel even at 5°C.1.The process shown in Fig. 1 is known as a process for producing gelatin. However, the major difference between acid-treated gelatin and lime-treated gelatin is that the resulting products have different isoelectric points. In other words, acid-treated gelatin has a pH of 7.
~9, and contains many amino groups, whereas
Lime-treated gelatin (d Because most of the amino groups change to carboxyl in the lime treatment process, the isoelectric point pH 4.8-5
．． It is about 1. Therefore, acid-treated gelatin has more dyeing positions (that is, amine groups) for acidic dyes and has the property of being easily dyed.

On the other hand, it is known that the gelatin temperature decreases as the molecular weight of gelatin decreases. Therefore, in the present invention, collagen in skin and bones is desirably treated with hydrochloric acid in advance to remove unnecessary organic substances, and further decomposed and extracted with heat decomposition or proteolytic enzyme.
By producing acid-treated low-molecular-weight gelatin of about OOOO and adjusting the photosensitive solution, we have been able to prevent gelatinization during coating, and also have good dyeability, making the colored base film thinner.
The present invention is characterized by providing a method suitable for producing color fill.

This acid-treated low-molecular-weight gelatin has almost the same characteristics as general lime-treated high-molecular gelatin, except that it is easily dyed with acid dyes and has a low gelation temperature.
It is also possible to dissolve it in water at room temperature, that is, to develop it.

Description of Examples First, collagen in the skin and bones is treated with hydrochloric acid to remove unnecessary organic substances, and then acid or alkali is added to thermally decompose it, and desalination is performed with an ion exchange resin. Acid-treated low-molecular-weight gelatin having a molecular weight of 0 to 0,000 is prepared.

Next, water is added to a predetermined concentration, and a photopolymerization initiator (photosensitive main agent 2, such as ammonium dichromate) and an auxiliary agent (such as alcohol) are added.

Add chromium sulfur, benzoin tincture, etc.) and adjust the photosensitive solution. After that, after performing the above-mentioned process, i.e., removing air bubbles, it is applied to a specified glass substrate, pre-baked, exposed to ultraviolet light using a photomask, developed with cold water (3 minutes), and then burned at 150°C. After this, a color filter is manufactured by dyeing with an acid dye at 80° C. for about 10 minutes.

In addition, by forming a color fill cloth of multiple colors on the substrate, again applying a photosensitive liquid on the resist dyeing resin film, and repeating pattern formation and dyeing, it is easy to obtain multiple colors. You can create mosaic-like color fills.

Hereinafter, detailed examples of the photosensitive liquid used for manufacturing the color filter of the present invention will be described.

(Example 1) Each of the following substances: 0 water 100 OCC O acid-treated gelatin (molecular weight 5,000 to 20,000)
00JiLO Ammonium dichromate 401 0 Alcohol 60 CCO Benzoic tincture 50 QC O Chromium alum (0.2% aqueous FA solution) 20 cc was thoroughly mixed and dissolved (60-60°), then cooled to 20°C. The gelation did not occur and the viscosity was 14% at room temperature.
It was 00 pS. After coating on a glass substrate, UV exposure and cold water phenomenon (3 minutes) using a chrome mask with a test pattern formed, followed by Nippon Ciba Geigy Co., Ltd. Upon staining, the pattern shown in FIG. 2(a) was obtained. Note that the thickness of the photoresist film at this time was 0.68 μm.

(Example 2) In Example 1, the amount of ammonium dichromate, which is the main photosensitive agent, was changed to 40y-, and gelatin lime-treated low-molecular-weight gelatin (
When the gelation was carried out under the same conditions except that 300 particles with a molecular weight of 10-20,000) were used, gelation did not occur, the viscosity was about 210 cps, and a similar pattern was formed. 80℃ at Scarlet RE,
After staining for 10 minutes, the result was as shown in FIG. 2(b), and even though the thickness of the photosensitive film was 0' near μm as in Example 1, the dyeing was not as great as in Example 1. The visible spectral characteristics are shown in Figure 3. In the figure, (a) shows oxidized gelatin, and (b) shows lime-treated gelatin.

(Example 3) In Example 1, 1 of ammonium dichromate, which is the main photosensitive agent,
Juice 25y-, gelatin and lime f' (molecules ■100,000 ~
250,000) photographic gelatin 150? The experiment was conducted under the same conditions except that the gel was completely gelled even at a room temperature of 25°C! There was even . Therefore, after remelting at 60° C., coating, exposure, and development were carried out. Although the phenomenon was carried out in cold water for 10 minutes, a sharp pattern was not formed.

The results after staining are shown in Figure 4.

(Example 4) Each of the following substances, namely 0 water 10oOCc O acid-treated gelatin (molecular weight 30.Q○○ to 70.O○○
) 00f 0 Potassium dichromate 101 0 Ammonium dichromate 30y O Lead nitrate 2.51 0 Alcohol 30 After thoroughly mixing and dissolving CC (50 to 60°C), it was cooled to 20°C and left for one day. , no gelation occurred and the viscosity was 160
It was cps. Further, after coating on a glass substrate, UV exposure was performed using a chrome mask on which a test pattern was formed, and a pattern with a line width of about 3 μm could be formed. Moreover, when dyeing was carried out under the same conditions as in Example 1, the same level of dyeing as in Example 1 was achieved.

(Example 6) In Example 4, acid-treated gelatin (molecular weight 5.
○○○~20,000) Even when the same conditions were used except that 300y- was used, gelation did not occur, the viscosity was about 140 cps, and the same pattern and staining as in Example 4 were obtained.

(Example 6) In Example 4, if the experiment was carried out under the same conditions except that 150% of general industrial lime-treated gelatin (molecular weight 60,000 to 250,000) was used as the gelatin, In this case, gelation occurred at around 3Q°C, but gelation did not occur after addition of ammonium dichromate. On the other hand, pattern formation and dyeing density are as follows in Example 2.
It was equivalent to

In addition to the above examples, acid-treated low-molecular gelatin (molecular weight 5
, 000 to 20,000) and a small amount of acid-treated or lime-treated polymer Seratin (molecular weight 100,000 to 20,000) is mixed in to produce a product that does not gel at room temperature and has a high viscosity.
I was able to prepare a photosensitive solution that stained well with acid dyes.

(Example 7) In Example 1, acid-treated low-molecular-weight gelatin (molecular weight 5.00 to 20.ooo) and lime-treated high-molecular-weight gelatin (molecular weight 1Q0,000 to 200.0) were added to gelatin.
When the experiment was carried out under the same conditions except that a mixture of 0.00) and 40% was used, the same results as Example 1 were obtained, except that the viscosity at room temperature was 250 cps.

Although the photosensitive solution described above uses dichromate as a photopolymerization initiator, it is possible that the same effect can be obtained with a radical initiator, such as a diazo compound or a peroxide. it is obvious. Note that benzoin tincture, which is an auxiliary agent used in the example, has the effect of controlling gelatin stars and has a hardening effect, and alcohol has the effect of preventing foaming and improving spreadability.

As mentioned above, acid-treated low molecular weight gelatin (molecular weight 600
0A-300oo1 or 3000ON70000)
By adjusting the gelatin photosensitive solution whose main ingredient is
It has good stainability with acid dyes and does not gel even at room temperature. Therefore, by producing and utilizing a gelatin-based photosensitive liquid whose viscosity changes slowly, the process for producing color filters can be greatly simplified. In other words, by using this photosensitive liquid, it is easy to control the film thickness even if the coating process is performed at room temperature, and uniform coating is possible, which streamlines the coating process for substrates during color fill production. , the energy saving effect will be very large. Furthermore, the developing process can be performed using cold water, which is very advantageous.

Furthermore, the dyeing density per medium thickness can be increased by using acid-treated gelatin. That is,
Even if the coating film thickness is about 0.5 μm, a sufficient dyeing density that can be used as a color fill can be obtained, so it is easy to form a fine pattern of about 6 μm.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a general gelatin manufacturing process, FIG. 2(a) is an enlarged view of a pattern formed using acid-treated gelatin in Example 1 of the present invention, and FIG. 2(b) is an example. FIG. 3 is an enlarged view of a pattern formed using a lime-treated gelatin photosensitive solution for comparison with Example 1 of the present invention and a pattern formed using a photosensitive solution in Example 2 for comparison. Diagram showing visible spectral characteristics of dyed material, No. 4
The figure is an enlarged view of a pattern that was attempted to be formed using the photosensitive liquid of Example 3, but shows that pattern formation is not so easy with cold water development. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 (D+1/υpm

Claims (2)

[Claims] (1) A step of preparing a photosensitive solution containing decomposed low-molecular-weight gelatin and water as main components and adding a photopolymerization initiator and an auxiliary agent, a step of coating it on an arbitrary substrate, and a step of exposing it to light using a predetermined photomask. A method for producing a color fill material, which comprises a step of further development to form a required gelatin pattern, and a dyeing step with an acid dye after further burning. (2) Decomposed low-molecular-weight gelatin is made by thermally decomposing high-molecular acid-treated gelatin and has an average molecular weight of