JPH09171261A - Alkali developer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent incomplete development and surface stain and to form a colored pattern in a high yield from a colored photosensitive compsn. prepd. by dispersing an org. pigment and/or an inorg. pigment without causing the surface roughening of a colored pattern remaining after development by specifying the amt. of a nonionic surfactant based on the amt. of basic substances. SOLUTION: An aq. buffer soln. contg. a combination of a strong basic substance with a weak basic substance is blended with 25-1,000 pts.wt. nonionic surfactant based on 100 pts.wt. of the basic substances to obtain the objective alkaline developer not causing incomplete development and excellent in surface stain preventing effect. When org. ammonium hydroxide or a combination of it with other strong basic substance is used as the strong basic substance, the surface roughening of a colored pattern remaining after development is also prevented, thus obtaining an excellent alkaline developer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the production of a color filter, which is a component of a color liquid crystal display, by using a negative colored photosensitive composition containing an organic pigment and / or an inorganic pigment dispersed therein to form a colored pattern. The present invention relates to an alkaline developing solution used in the process.

[0002]

2. Description of the Related Art Many proposals have been made for a method of manufacturing a color liquid crystal display (LCD), but recently, indium has been formed on a color filter having RGB pixels and a black matrix formed on a transparent substrate such as glass. A method of forming a transparent electrode by sputtering a transparent conductive film such as tin oxide (ITO), further forming an alignment film on the transparent electrode, and disposing a liquid crystal is becoming common.

There are various methods for producing the color filter used here, and a pigment dispersion method, a dyeing method, a printing method and a method of laminating like a dry film are known. At present, the pigment dispersion method is predominant among these methods. The pigment dispersion method is a method for producing a color filter by applying a negative type colored photosensitive composition in which an organic pigment and / or an inorganic pigment are dispersed by a spin coater or the like to form a predetermined coloring pattern. .

Conventionally, only the RGB color layers have been used, but recently, a light-shielding layer serving as a black matrix has also been formed from a photosensitive composition in which a pigment such as carbon black is dispersed. The negative colored photosensitive composition (hereinafter simply referred to as "colored photosensitive material") can be cured with an organic pigment and / or an inorganic pigment for coloring or light shielding, ultraviolet rays, etc., and alkali development. A liquid-soluble resin component is contained as an essential component. These pigments and resin components are required to be promptly dissolved or dispersed in the alkali developing solution when removing unnecessary portions in the developing step with the alkali developing solution.

However, there is a problem that a colored photosensitive composition that should be completely removed during development remains (development residue), and it is once removed from the glass substrate and dissolved in an alkali developing solution.
The pigment and resin components that were dispersed redeposit on the glass substrate, black matrix or cured colored layer (background stain).
Problems often arise. Such a residue causes unevenness in color of the color filter and causes a problem such as poor adhesion in a subsequent process. Therefore, an alkaline developer that can sufficiently dissolve, disperse and remove the pigment and the resin component contained in the colored photosensitive composition at the development stage causes surface roughness especially to the coloring pattern remaining after the development processing. There has been a demand for an alkaline developing solution that does not cause it.

As a developing solution for solving the above problems, an aqueous solution containing an alkaline compound and a nonionic surfactant having a pH of 9 to 13 and containing 0.01 to 1. There has been proposed an alkaline developer for a radiation-sensitive composition, characterized in that it is contained in an amount of 0% by weight (JP-A-7-120935).

However, among the above-mentioned developing solutions, the non-buffering type developing solution using a strong base as an alkaline compound has high basicity, so that the pattern portion cured by exposure is liable to be roughened, swollen or peeled off. Absent. Further, if the basicity is high, the pigment or the resin component becomes difficult to dissolve and disperse, which may cause undeveloped residue or background stain.

In this non-buffer type developer, if the aqueous solution concentration of the strong base component is diluted to less than 0.05% by weight, the surface roughness will be reduced. However, since the absolute amount of the base component is insufficient, it is necessary to use a large amount of the developer, or the developer is deteriorated due to the dissolution and dispersion of the pigment and the resin component and the absorption of acidic gas such as carbon dioxide gas in the atmosphere. Get faster That is, since it causes the undeveloped residue and the occurrence of background stains,
Workability in the developing process and repeated use become difficult.

On the other hand, in a non-buffer type developing solution using a weak base as an alkaline compound, it becomes difficult for the pigment or resin component to dissolve and disperse, resulting in development residue and scumming.

[0010]

SUMMARY OF THE INVENTION The present invention prevents the undevelopment of undeveloped materials and background stains, which are the drawbacks of the conventional materials described above,
Alkaline developer capable of forming a colored pattern from a colored photosensitive composition having an organic pigment and / or an inorganic pigment dispersed therein at an excellent yield without causing surface roughness to the colored pattern remaining after the development treatment. Is provided.

[0011]

Means for Solving the Problems The inventors of the present invention have made extensive studies as to an alkaline developing solution suitable for a colored photosensitive composition in which an organic pigment and / or an inorganic pigment are dispersed, and as a result, found that a strong basic substance was obtained. A buffered aqueous solution in which a weakly basic substance is combined with a nonionic surfactant, and the amount of the nonionic surfactant is 25 parts by weight or more and 1000 parts by weight or less based on 100 parts by weight of the basic substance. By making the composition, it is possible to obtain an alkaline developer having no development residue and excellent in the prevention of background stains. Furthermore, as a strongly basic substance, organic ammonium hydroxide alone or in combination with another strongly basic substance can be used. It was found that an excellent alkaline developer which prevents the occurrence of surface roughness on the colored pattern remaining after the development can be obtained by the selection, and the present invention has been completed. This has led to the.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Examples of the material constituting the above colored photosensitive composition include, for example, "Photopolymer Handbook", edited by Photopolymer Society (published by Industrial Research Institute)
The alkali-soluble resin such as the epoxy acrylate-based, polyester acrylate-based or (meth) acrylate polymer-based described in (1) is blended with a photopolymerizable monofunctional or polyfunctional monomer, and a benzophenone-based or thioxanthone-based photopolymerization initiator. Specific examples of the composition and the like are disclosed in JP-A-7-13016 and JP-A-7-13331.
And colored photosensitive compositions described in JP-A-4-26801 and the like.

These colored photosensitive compositions are generally coated on a glass substrate by using a coating device such as a spin coater, a roll coater and a curtain coater, dried and then exposed to an active energy ray such as ultraviolet rays through a predetermined mask. A colored pattern is formed by exposing and then removing the unexposed portion by development.

Next, the details of each component contained in the alkaline developer for a colored photosensitive composition according to the present invention will be described. Inorganic strong basic substances include lithium hydroxide,
Examples of alkali metal and alkaline earth metal hydroxides such as sodium hydroxide and potassium hydroxide and inorganic weak basic substances include alkali metal or alkaline earth metal carbonates such as lithium carbonate, sodium carbonate and potassium carbonate. Salts and hydrogen carbonates are mentioned.

Examples of the organic strongly basic substance include organic ammonium hydroxide, and specific examples thereof include tetramethylammonium hydroxide and trimethyl (2-hydroxyethyl) ammonium hydroxide (choline). To be

In the present invention, a buffering aqueous solution is prepared by combining a strongly basic substance and a weakly basic substance. By using the buffered aqueous solution, an appropriate pH can be obtained.
In the region, the effect of keeping the aqueous solution of the basic substance at a high concentration becomes large, and the pH value is easily stabilized even if the pigment and the resin component are dissolved and dispersed. Further, as compared with the developing solution in which the weak base alone is selected as the alkaline compound and the developing solution in which the strong base alone is selected, the undeveloped residue and the background stain are significantly improved.

Preferred combinations include alkali metal hydroxide and carbonate (hydrogen) salt, organic ammonium hydroxide and alkali metal carbonate (hydrogen) salt, and organic ammonium hydroxide, alkali metal hydroxide and alkali metal. Consisting of carbonic acid (hydrogen) salt of
The original system is mentioned. Among these, by selecting organic ammonium hydroxide alone or a combination with an alkali metal hydroxide as the strongly basic substance, an excellent alkaline developer that prevents the occurrence of surface roughness for the colored pattern remaining after the development treatment can be obtained. It is more preferable because it can be obtained.

Specifically, sodium hydroxide and sodium carbonate and / or potassium carbonate; potassium hydroxide and sodium carbonate and / or potassium carbonate;
Tetramethylammonium hydroxide and sodium carbonate and / or potassium carbonate; tetramethylammonium hydroxide, sodium hydroxide and sodium carbonate and / or potassium carbonate; tetramethylammonium hydroxide, potassium hydroxide and sodium carbonate and / or potassium carbonate Combinations can be mentioned. A system in which an organic ammonium hydroxide which is a strong base is added to a combination of a carbonate and a hydrogen carbonate may be used. It should be noted that the combination of carbonate and hydrogen carbonate is not preferable because development residue is likely to occur.

The mixing ratio of the alkali metal hydroxide and carbonate is preferably hydroxide / carbonate = 50/50 to 1/99 (parts by weight), more preferably 20/80 to 5/95.
(Parts by weight). The compounding ratio of organic ammonium hydroxide and alkali metal carbonate is 60/40 to 1
/ 99 (parts by weight) is preferable, and more preferably 40/6
It is 0 to 10/90 (parts by weight). The compounding ratio of the organic ammonium hydroxide, the hydroxide of alkali metal and the carbonate is 50/50 to 1 / strong base / carbonate.
99 (parts by weight) is preferable, and more preferably 20/80
˜5 / 95 (parts by weight).

The concentration of the basic substance in the aqueous solution must be changed depending on the colored photosensitive composition used, but is usually 3% by weight.
~ 0.05 wt% is preferred, more preferably 1 wt%
~ 0.1% by weight. If both the mixing ratio and the concentration of the alkali developer are too basic, the surface of the pattern portion cured during exposure tends to be rough, and if it is too low, undeveloped residue or scumming is likely to occur.

As the nonionic surfactant, polyoxyethylene (propylene) alkyl ether, polyoxyethylene (propylene) alkenyl ether, polyoxyethylene (propylene) alkyl (alkenyl) phenyl ether, polyoxyethylene (propylene) alkyl. Examples thereof include (alkenyl) naphthyl ether, sorbitan fatty acid ester, polyoxyethylene (propylene) fatty acid ester, polyoxyethylene (propylene) alkylamine, alkylalkanolamide and polyoxyethylene polyoxypropylene block polymer. Propylene) is preferable because it has a low foaming property and the pigment can be easily dispersed.

The polyoxyethylene (propylene) type surfactant has a cloud point of 40 ° C. to 100 ° C. and HL.
B having a range of 10 to 18 is preferable because it has a low foaming property.
Specific products within this range include Emulgen 10
8, 109P, 120, 220, 320P, 409P,
420, 709, 810, 911, 913, 920, A
-60, A-90, B-66, L-40, L-70, P
P-150 and PP-250 (all manufactured by Kao Corporation)
And the like.

The mixing ratio of the basic substance and the nonionic surfactant must be 25 parts by weight or more and 1000 parts by weight or less based on 100 parts by weight of the total basic substance. It is preferably not less than 500 parts by weight and not more than 500 parts by weight. If the blending ratio of the nonionic surfactant is too low, it has no effect on the development residual and background stain prevention, and if it is too high, foaming or roughening of the surface of the patterned portion upon exposure tends to occur. In addition, unnecessary surfactants cause a cost increase during waste liquid treatment. The alkaline developer for a colored photosensitive composition according to the present invention can be used usually in the range of 15 ° C. to 40 ° C., and can be used for general developing means such as dipping, spraying or ultrasonic irradiation.

[0024]

The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Preparation of Colored Photosensitive Composition Methacrylic acid, methyl methacrylate and n-butyl acrylate were copolymerized using azobisisobutyronitrile as a polymerization initiator and propylene glycol monomethyl ether acetate as a solvent, and then glycidyl methacrylate in the presence of triethylamine. Unsaturation equivalent 0.5 meq / g, acid value 0.9 meq / g,
An acrylic polymer having a weight average molecular weight of 13,000 was obtained.

To 80 parts by weight of this acrylic polymer (solid content), 20 parts by weight of trimethylolpropane triacrylate as a photopolymerizable polyfunctional monomer, and as a red pigment, a quinacridone pigment and a disazo yellow pigment (compounding ratio 80/20 ( 18% by weight, and Irgacure 90 as a benzophenone-based photopolymerization initiator.
5 parts by weight of 7 (manufactured by Ciba Geigy) was added, and the pigment was dispersed by kneading with a three-roll mill, and then diluted with a solvent propylene glycol monomethyl ether acetate to prepare a colored photosensitive composition.

Evaluation method of developing solution: To 100 parts of developing solution containing a basic substance and a surfactant,
Two parts of the above-mentioned red photosensitive composition was added, stirred well and allowed to stand, and the transparency and foamability were visually observed. The test was prepared so that the concentration of the basic substance in water was 1% by weight.
A developing solution at 5 ° C. was used. A sample with a high transparency was evaluated as 5, and a sample with a marked turbidity was evaluated as 1. It is shown that the highly transparent developer well dissolves or disperses the pigment and the resin component contained in the colored photosensitive composition. The foaming property is such that after the developer is put in a glass container and the lid is closed, the container is shaken violently and then the container is allowed to stand, and the time until foam disappears is less than 30 seconds, weaker than 30 seconds and less than 60 seconds. In, 6
Those exceeding 0 seconds were evaluated as strong. The surface roughness of the colored pattern was 500 mJ / c with the colored photosensitive composition spin-coated on a glass substrate so that the film thickness was 2 μm.
The film was exposed to light and cured at m 2, then immersed in a developing solution at 25 ° C. prepared so that the concentration of the basic substance in the aqueous solution was 0.3%, for 30 seconds, and then the appearance of the coating film surface was visually observed for evaluation. Those having no difference between the portion immersed in the developing solution and the untreated portion were judged to have no surface roughness, and those having fog in the immersed portion were judged to have surface roughness.

Comparative Examples 1 to 11 Developers were prepared by using various nonionic surfactants such that sodium carbonate and the surfactant were each 1% by weight, and the above-mentioned evaluation was carried out. The results are shown in Table 1. A nonionic surfactant having a cloud point of 40 ° C. to 100 ° C. and an HLB of 10 to 18 is preferable because it has a high transparency and weak foaming property.

[0029]

[Table 1]

Examples 1 to 13 and Comparative Examples 12 to 19 1% by weight of Emulgen A-90 as a nonionic surfactant, sodium carbonate as a weak base, and sodium hydroxide or potassium hydroxide as a strong base are selected. Comparative examples 1 to 1 by changing various combinations and concentrations of the basic substances.
The same evaluation as in 1 was performed. Table 2 shows the results. A buffer system in which sodium carbonate or a combination of potassium hydroxide and sodium carbonate gives a higher transparency and is preferable to the use of sodium carbonate alone. Comparative Example 1
In No. 9, strong surface roughness occurred.

[0031]

[Table 2]

Examples 14 to 21 and Comparative Examples 20 to 23 Emulgens A-90 and B-66 are used as surfactants.
5 to 10 parts per 100 parts of inorganic basic substance
Table 3 shows the evaluation results when the addition amount was changed up to 000 parts.
Shown in The types and compounding ratios of the weak base and the strong base used were sodium carbonate / sodium hydroxide = 80/20 (parts by weight). The foamability was evaluated even when the colored photosensitive composition was not added, that is, in the unused state. Generally, when a surfactant is added in a small amount, it dissolves pigments and resin components,
Poor dispersion and poor transparency. However, if a surfactant is added more than necessary, the foaming property becomes strong, and workability is deteriorated particularly in the case of performing spray development or circulating the developer, which is not preferable.

[0033]

[Table 3]

Comparative Examples 24 to 26 Sodium hydroxide, potassium hydroxide or tetramethylammonium hydroxide (referred to as "TMAH" in the table) as a strong base, and Emulgen A-90 as a surfactant were selected. An evaluation was performed. Table 4 shows the results. In both cases, the surface was significantly roughened and the transparency of the liquid was poor. Moreover, the amount of sediment was very large.

[0035]

[Table 4]

Examples 22 to 28 In a buffer solution system using inorganic sodium hydroxide or potassium hydroxide as a strong base and sodium carbonate as a weak base, Emulgen A-90 was selected as a surfactant, and the above-mentioned evaluation was conducted. I did. Table 5 shows the results. If the mixture ratio of strong basicity is high, surface roughness tends to occur, while
When the blending ratio is low, the transparency is also lowered, and the solubility and dispersibility of the pigment or resin component contained in the colored photosensitive composition in the developing solution is deteriorated.

[0037]

[Table 5]

Examples 29 to 35 A binary system using tetramethylammonium hydroxide (referred to as "TMAH" in the table) alone or tetramethylammonium hydroxide and sodium hydroxide as a strong base and sodium carbonate as a weak base or In the ternary buffer system, A- is used as a surfactant.
90 was selected and the above-mentioned evaluation was performed. Table 6 shows the results. By using tetramethylammonium hydroxide even if the blending ratio of the strong base is high, the surface of the colored pattern is not roughened, and on the other hand, the transparency is high and the pigment or resin component contained in the colored photosensitive composition is contained in the developer. Dissolution in
It can be seen that a developer having high dispersibility can be obtained.

[0039]

[Table 6]

[0040]

According to the present invention, in manufacturing a color filter which is a constituent member of a color liquid crystal display,
It is possible to provide an alkaline developer for a colored photosensitive composition, which is suitable for the production of a color filter having no color unevenness or poor adhesion and no surface roughness of a colored pattern, and is extremely useful in practice.

Claims (2)

[Claims] 1. A buffered aqueous solution containing a nonionic surfactant, which is a combination of a strongly basic substance and a weakly basic substance, and 25 parts by weight of the nonionic surfactant per 100 parts by weight of the basic substance. An alkali developing solution for a negative type colored photosensitive composition, in which an organic pigment and / or an inorganic pigment is dispersed, which is in the range of 1 part by weight to 1000 parts by weight. 2. The alkali developing solution according to claim 1, wherein an organic ammonium hydroxide is used alone or in combination with another strong basic substance as the strong basic substance.