JPH01282504A - Formation of color filter - Google Patents

Abstract

PURPOSE:To execute dyeing to a high density by forming patterns on a substrate by using a photosensitive material prepd. by adding a specific diazonium salt to a specific copolymer soln. having 30,000-300,000 average mol.wt., then by dyeing the patterns with water soluble dyes. CONSTITUTION:The patterns are formed on the substrate by using the photosensitive agent prepd. by adding 10-30wt.% diazonium salt to the soln. of the copolymer which is obtd. by copolymerizing acrylamide at the ratio higher by 4mol or over per 1mol N-(1,1-dimethyl-3-oxobutyl)acrylamide and has 30,000-300,000 average mol.wt. The patterns are thereafter dyed by the water soluble dyes. The dyeing to the high density is executed by the dyes according to this method; in addition, the color filters have heat resistance and the adhesiveness thereof to the substrates consisting of glass, resins such as acryl and silicon wafers is improved. Exfoliation of the patterns is substantially obviated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to color displays, color image sensors, etc.
The present invention relates to a method for creating color filters for color separation, which are used in processing such as transferring and analyzing color images.

[Conventional technology]

Currently, methods for producing color filters used in liquid crystal displays, color image sensors, etc. include dyeing methods, printing methods, electrodeposition methods, interference film methods, and dye vapor deposition methods. Among them, the dyeing method is generally put into practical use as the simplest and most reliable method.

To create a color filter using the dyeing method, first, glass,
A water-soluble polymer to be colored is dissolved in water and a photosensitive solution containing a photo-crosslinking agent is applied to a substrate such as a transparent resin such as acrylic or a silicon wafer to a predetermined thickness, and then heated and dried to form a film. form. Next, this film is irradiated with ultraviolet rays through a mask and developed to form a fine pattern in the form of stripes or mosaics. Then, it is dyed with a predetermined dye to form a colored pattern.

Next, a curable resin such as a photocurable or thermosetting acrylic resin, urethane resin, or epoxy resin is provided as an intermediate layer on the colored pattern, and the second and third layers are formed in the same manner, and the top layer is A color filter is created by providing a protective film on the

The material to be colored as a coloring pattern used to create a color filter is a water-soluble polymer compound that can be dyed with a water-soluble dye, such as gelatin or casein. Dichromate is added to these weakly alkaline colloidal solutions to form a photosensitive solution, thereby obtaining colored patterns.

[Problem to be solved by the invention]

However, since gelatin, casein, etc. are natural proteins, they have several problems as described below.

(1) Since the composition of the polymer compound obtained varies depending on the type of raw material, season, and location, it is important to obtain a certain level of stainability, sensitivity, resolution, and smoothness when applied to the film. Have difficulty.

(2) Since it is a protein, it is easily decomposed by microorganisms such as bacteria, and it is also easily deteriorated by the proteolytic enzymes or waste products of microorganisms. Furthermore, weakly alkaline colloid solutions such as gelatin and casein are unstable because colloids tend to aggregate during storage, and storage stability is poor.

(3) Films such as gelatin and casein have poor adhesion to plastic substrates such as glass and acrylic and are easily peeled off.

(4) Natural proteins such as gelatin and casein contain sodium, potassium, calcium, magnesium,
It is very difficult to remove metals such as iron and copper, and if used in a color filter without removing them, these metals may be contained in the liquid crystal when used in a liquid crystal display. may spread, causing malfunctions and failures.

(5) If heat resistance is poor and peels off during the heating drying process,
There is.

(6) Some dyes hardly dye;
Also, if you leave the dye uneven, the dyeing properties will be poor.

By the way, in JP-A-57-168248, acrylamide and diacetone acrylamide (for example, N-(1
, 1-dimethyl-3-oxobutyl)acrylamide)
A photosensitive liquid is disclosed in which a diazo resin is added in an amount of 2 to 10% by weight to a copolymer. However, since this photosensitive liquid was developed for use in the fields of plate making, printing, and drawing, it is not suitable for producing color filters that require high resolution of at least 10 μm or less and high sensitivity. Another problem is that depending on the type of dye, it may not be possible to dye at a high concentration.

[Means to solve the problem]

As a result of extensive research to solve these problems, the present inventors found that acrylamide and N-(1,1-dimethyl-
A diazonium salt having a molecular weight of 10 to 30 or 20 to 4 to a copolymer having a specific average molecular weight obtained by copolymerizing 3-oxobutyl acrylamide at a specific molar ratio.
After forming a pattern on the substrate using a photosensitive agent containing 0% by weight of dichromate, dyeing it with a water-soluble dye, or if necessary, treating it with an aqueous chromic acid anhydride solution and then dyeing it, The present invention was completed based on the knowledge that the problems could be solved.

That is, the present invention is based on copolymerization of more than 1 mol of acrylamide per 1 mol of N-(1,1-dimethyl-3=oxobutyl)acrylamide, with an average molecular weight of 3
0.000 to 300.000 copolymer solution, 10 to 30% by weight of diazonium salt or 20% by weight based on the copolymer
It is characterized by forming a pattern on a substrate using a photosensitive agent containing ~40% by weight of dichromate, then treating it with an aqueous chromic acid anhydride solution if necessary, and then dyeing it with a water-soluble dye. This is a method of creating a color filter.

When trying to use a copolymer made of a combination of two or more monomers in place of conventionally used gelatin, casein, etc., various combinations of monomers can be considered. However, when used in the color filter of the present invention, it is desirable to be water-soluble, and also requires good adhesion to resins such as glass and acrylic, and substrates such as silicon wafers.

The most preferred combination of monomers that meets these conditions is a combination of acrylamide and N-(1,1-dimethyl-3-oxobutyl)acrylamide. Acrylamide is water-soluble, and when a polymer of N-(1,1-dimethyl-3-oxobutyl)acrylamide is formed into a film, it has excellent adhesion to resin substrates such as acrylic. These copolymers have both properties. Also, acrylamide and N-(1,1-
Copolymers of dimethyl-3-oxobutyl)acrylamide are also excellent in terms of economy and ease of handling.

The higher the acrylamide content of a copolymer of acrylamide and N-(1,1-dimethyl-3-oxobutyl)acrylamide, the better the solubility in water, but the lower the adhesion to resin substrates such as acrylic. Also N
The higher the content of -(1,1-dimethyl-3-oxobutyl)acrylamide, the better the adhesion to resin substrates such as acrylic, and the higher the resolution when used as a photosensitive liquid, but the water solubility is lower. From these points of view, the blending ratio of acrylamide and N-(1,1-dimethyl-3-oxobutyl)acrylamide is preferably 1 mole of N-(1,1-dimethyl-3-oxobutyl)acrylamide to 4 mols of acrylamide. The amount is more than 1 mole, more preferably 10 moles or less.

If the amount of acrylamide exceeds 10 moles, wrinkles may occur in the resulting pattern.

In addition, the average molecular weight of the copolymer is 30,000 to 3.
A range of 00.000 is preferred, particularly preferably 30.000.
The range is from 000 to 200.000. If it is smaller than this range, the strength when formed into a film will be reduced, and if it is larger than this range, the resolution will be reduced when used as a photosensitive liquid, making it impractical.

The above-mentioned copolymer is made into an aqueous solution, and then a photosensitive liquid is prepared by adding a photocrosslinking agent and a crosslinking agent. Conventionally known photocrosslinking agents can be used, but typical ones include dichromates such as ammonium dichromate and potassium dichromate, p-diazonium diphenyl sulfate or chloride, and pyridine sulfonate. , zinc chloride double salt, and formalin condensates of these salts, and dichromic acid and diazonium salts are particularly preferred since the resulting coating pattern is hardly colored. However, diazonium salts have higher sensitivity and better resolution than dichromate salts, making it possible to obtain finer patterns. Dichromate has the advantage of being inexpensive and having excellent storage stability.

The amount of photocrosslinking agent added varies depending on the type of photocrosslinking agent used, but for example, when using dichromate, it is preferably in the range of 20 to 40% by weight based on the solid content of the photosensitive liquid, and in the case of diazonium salts. is 10% based on the solid content of the photosensitive liquid.
A range of 30% by weight is preferred.

There are various types of water-soluble dyes used to create color filters, and depending on the type of dye, the color depth of the pattern differs even when dyed with the same color. Also, some colors are difficult to dye, especially cyan,
Colors such as green are difficult to dye. If it is necessary to dye a color that is difficult to dye, such as cyan or green, at a high concentration, the film formed on the substrate can be immersed in an aqueous solution of chromic anhydride before the dyeing process. Can be dyed.

An aqueous solution of chromic acid anhydride has the effect that by immersing a substrate on which a pattern has been formed in the aqueous solution, chromium permeates into the pattern coating and improves the colorability of the dye.

It is preferable to use the aqueous chromic acid anhydride solution at a concentration in the range of 1 to 20 parts by weight, and sufficient effects can be obtained with an immersion time of about 10 to 60 seconds.

A general processing method is to apply the photosensitive liquid onto a substrate, heat and dry it, then expose it to light through a mask, develop it, and dry it to obtain a film in which a pattern is formed. Next, the film is immersed in a chromic anhydride aqueous solution for several tens of seconds to allow the chromic anhydride aqueous solution to penetrate into the film, and then dried and dyed.

〔Example〕

Next, examples of the present invention will be shown to explain the present invention in more detail.

Example 1 Acrylamide 677 in water 90009, N-(1,1
-dimethyl-3-okinobutyl)acrylamide 32:
M (molar ratio 5:1) was dissolved, filtered, transferred to a three-ring flask, heated while stirring, and when the temperature reached 50°C, azobis-based polymerization initiator VA-044 (manufactured by Wako Tsumugi Yakuhin Co., Ltd.) 302 was added. A solution prepared by dissolving 1002 in water was added, the temperature was raised to 66°C, and a polymerization reaction was carried out for 2 hours. The mixture was returned to room temperature and further diluted with water to obtain a resin solution having a resin concentration of 3.8% by weight. This was filtered to obtain a colorless and transparent water-soluble polymer compound solution. The viscosity at this time is 5QcP (25
℃), and the average molecular weight was 150,000 as determined by liquid chromatography.

A photosensitive solution was prepared by adding a 1O heavy weight type ammonium chromate aqueous solution 209 to the above water-soluble polymer compound solution 1001.

This was spin-coated onto a 1- and 2-inch thick glass plate and a 2-meter thick acrylic plate that had been degreased and cleaned to obtain a 1-μm-thick dry film. Next, the film was irradiated with ultraviolet rays having a wavelength of 330 nm and an intensity of 100 mJ through a mask, followed by shower development with pure water for 10 seconds and drying to form a pattern.

Cyan 2F, magenta 10P1 yellow 2 as dyes
P, Red 14P1 Green IP.

Acetic acid was added to a 0.5% by weight aqueous solution of Blue 5P (all trade names manufactured by Nippon Kayaku Co., Ltd.) to give a staining solution of 0.2% by weight.

The substrate on which a pattern was previously formed in this dyeing solution was left to rest for 1 minute, then washed with water and dried. The dyed patterns were observed, but no peeling of the patterns was observed on either the glass plate or the acrylic plate. The staining results are shown in Table 1. As is clear from Table 1, all except Cyan 2P and Green IP exhibited good dyeing properties.

Separately, prepare a glass plate and an acrylic plate with patterns formed in the same manner as above, immerse them in a 10% weight chromic acid anhydride aqueous solution for 30 seconds, wash with water, dry, and then stain in the same manner using Cyan 2P and Green IP. As a result, it showed good dyeability.

Comparative Example 1 A 10 weight type ammonium chromate aqueous solution 52 was added to a 3.8 weight type aqueous solution 1001 of casein to prepare a photosensitive solution. Using this, pattern formation was performed in the same manner as in Example 1.
When dyeing was performed, the pattern formed on the acrylic plate showed some lifting. The staining results are shown in Table 1.

(Margins below) Table 1. However, △ indicates that it is difficult to dye, ○ indicates that it is normal, and ◎ indicates that it dyes well.

The numbers in parentheses show the results for those immersed in a 10% by weight chromic anhydride aqueous solution.

Examples 2 to 5 Acrylamide and N-(1,1-dimethyl-3-oxobutyl)acrylamide were dissolved in 9,000 ml of water at the mixing ratios shown in Table 2, and after filtering, the mixture was transferred to a three-lens flask and mixed with stirring. When heated to 35℃, 2-acetic acid,! = 200'- inopropyl alcohol is added, then 61 parts of ammonium persulfate is added to 30 parts of water. An aqueous solution dissolved in was added. Finally, ammonium sulfite 5
A polymerization reaction was started by adding an aqueous solution of 2 dissolved in water 302, and after reacting at 62°C for 2 hours, the mixture was returned to room temperature, filtered, and ion-exchanged to obtain four types of colorless and transparent water-soluble polymer compounds. Ta.

Table 2 ■ indicates acrylamide, ■ indicates N-(1,1-dimethyl-3
-Formalin condensate of amine sulfate was added to a water-soluble polymer compound in an amount of 10 parts by weight to make a photosensitive solution, and patterns were formed in the same manner as in Example 1. Good patterns were obtained in all cases. It was done.

Next, the results of dyeing using the same method as in Example 1 are shown in Table 3. Furthermore, even better results were obtained when the pattern was formed and then immersed in a 10% by weight chromic anhydride aqueous solution for 30 seconds and dyed with Cyan 2P and Green IP.

Table 3 However, △ indicates that it is difficult to dye, and ◎ indicates that it is well dyed.

The numbers in parentheses show the results for those immersed in a 10% by weight chromic anhydride aqueous solution.

Examples 6 to 9, Comparative Example 2 Aqueous solutions of water-soluble polymer compounds polymerized in the same manner as in Examples 2 to 5 were added by adding 5 weight of formalin condensate of p-diazonium diphenylamine sulfate to the water-soluble polymer compound. Examples 6 to 9 were prepared by adding photosensitive liquids in such amounts as 10% by weight, 20% by weight, and 30% by weight.

Furthermore, a photosensitive solution was similarly prepared using acrylamide 2952 and N-(1,1-dimethyl-3-oxobutyl)acrylamide 705F (molar ratio 1:l), and Comparative Example 2 was prepared.

Spin coat each photosensitive solution onto a silicon wafer,
It was dried by heating on a hot plate at 90° C. for 90 seconds to obtain a film with a thickness of 1 μm. Each was exposed through a mask using a reduction projection exposure device N5R-1505G4D (manufactured by Nippon Kogaku Kogyo Co., Ltd., NA=0.42), developed, and then examined for resolution. Table 4 shows the results. The molar ratio of diacrylamide and N-(1,1-dimethyl-3-oxobutyl)acrylamide is in the range of 4,2:1 to 20:1, and the amount of formalin condensation of p-diazonium diphenylamine sulfate added is It was confirmed that good resolution could be obtained in the range of 10 to 30 weight ratio. Furthermore, there was no peeling or lifting of the pattern.

In Table 4, the values in () are the minimum exposure times that can form a pattern, and the shorter the exposure time, the higher the sensitivity.

Examples 10 to 13, Comparative Example 3 A water-soluble polymer compound aqueous solution polymerized in the same manner as Examples 2 to 5 was prepared by adding ammonium dichromate to the water-soluble polymer compound in an amount of 10% by weight, 20% by weight, respectively. They were added in amounts of 30% by weight and 40% by weight, respectively, to form a photosensitive solution, which was used as Examples 10 to 13, respectively.

Furthermore, a photosensitive liquid was prepared in the same manner as in Comparative Example 2 using a water-soluble polymer compound in the same proportion as Comparative Example 3.

Spin coat each photosensitive solution onto a silicon wafer,
It was dried by heating in an oven at 70 mm for 20 minutes to obtain a film with a thickness of 1 μm. Each was exposed to light through a mask and developed, but there was no peeling or lifting of the pattern. Table 5 shows the results of examining the resolution for each. As shown in the table, the molar ratio was in the range of 1:4.2 to 1:20, and it was confirmed that good resolution was exhibited when the amount of ammonium dichromate added was in the range of 20 to 40% by weight.

(Margin below) Table 5 However, the value in parentheses is the minimum exposure time that can form a pattern, and the shorter the exposure time, the higher the sensitivity.

Examples 14-23 Acrylamide and N-(1,1-dimethyl-3-oxobutyl)acrylamide were dissolved in 900 f of water at the mixing ratios shown in Table 6, filtered, transferred to a three-ring flask, and heated with stirring. Then, when the temperature reached 35°C, 2-acetic acid and 200-propanol were added, and then an aqueous solution of ammonium persulfate and ammonium sulfite each adjusted in the range of 5 to 202 was added to prepare Examples 2 to 5. In the same manner as above, water-soluble polymer compounds having different molar ratios and average molecular weights were obtained.

Table 6 ■ indicates acrylamide, ■ indicates N-(1,1-dimethyl-3
-oxobutyl)acrylamide.

A formalin condensate of p-diazonium diphenylamine pyridine sulfonate was added to each of these solutions in an amount of 10.20.30% by weight, based on the water-soluble polymer compound, to prepare a photosensitive solution. When patterns were formed on silicon wafers using the same method as in Example 9, good patterns were obtained in all cases. Table 7 shows the results of examining the resolution of the obtained patterns. From the table, the molecular weight of the water-soluble polymer compound is 30,000 to 300,
It was confirmed that good resolution of 8 μm or less could be obtained in the range of 000.

Table 7 Table 7 Continued [Effects of the Invention] According to the method of the present invention, it is possible to dye with a dye at a high concentration, and it is heat resistant and can be used for resins such as glass and acrylic.
This color filter has good adhesion to substrates such as silicon wafers, so there is no pattern peeling, and since it does not use natural proteins such as gelatin or casein, it is storage stable and has no adverse effects from metal ions. can be created.

Patent applicant: Tokyo Ohka Kogyo Co., Ltd.

Claims (4)

[Claims] (1) The average molecular weight obtained by copolymerizing more than 4 mol of acrylamide per 1 mol of N-(1,1-dimethyl-3-oxobutyl)acrylamide is 30,000.
A pattern is formed on the substrate using a photosensitive agent made by adding 10 to 30% by weight of diazonium salt to the copolymer solution to ~300,000 ml of copolymer, and then dyed with a water-soluble dye. A method for creating a color filter characterized by the following. (2) The average molecular weight obtained by copolymerizing more than 4 mol of acrylamide per 1 mol of N-(1,1-dimethyl-3-oxobutyl)acrylamide is 30,000.
After forming a pattern on a substrate using a photosensitizer made by adding 20 to 40% by weight of dichromate based on the copolymer to a copolymer solution of ~300,000, a pattern is formed on a substrate using a water-soluble dye. A method of creating a color filter characterized by dyeing. (3) The average molecular weight obtained by copolymerizing more than 4 mol of acrylamide per 1 mol of N-(1,1-dimethyl-3-oxobutyl)acrylamide is 30,000.
A pattern was formed on the substrate using a photosensitizer made by adding 10 to 30% by weight of diazonium salt to the copolymer to a copolymer solution of ~300,000, and immersed it in an aqueous chromic acid anhydride solution. A method for creating color filters that is then dyed with a water-soluble dye. (4) The average molecular weight obtained by copolymerizing more than 4 mol of acrylamide per 1 mol of N-(1,1-dimethyl-3-oxobutyl)acrylamide is 30,000.
A pattern was formed on the substrate using a photosensitizer made by adding dichromate in an amount of 20 to 40% by weight based on the copolymer to a copolymer solution of ~300,000 chromic acid anhydride. A method for creating a color filter characterized by immersing it and then dyeing it with a water-soluble dye.