JPH0519467A - Coloring paste for color filters - Google Patents

Abstract

PURPOSE:To obtain colored paste having very excellent developability, capable of sharp patterning and forming an excellent color filter. CONSTITUTION:This colored paste for a color filter is made of a photosensitive compsn. contg. an acrylic copolymer having an ethylenic unsatd. group and a carboxyl group in the side chain as the principal binder component, a coloring component, a multifunctional monomer and a photopolymn. initiator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter color paste suitable for color liquid crystal display devices such as color liquid crystal televisions and color liquid crystal displays for computers, which is composed of an acrylic photosensitive composition containing a coloring component. .

[0002]

2. Description of the Related Art Conventionally, various methods for producing a color filter using an acrylic photosensitive composition have been proposed. They mainly contain a mixture of an acrylic acid polymer and a compound having an ethylenically unsaturated group, and the main component acrylic acid polymer does not participate in the crosslinking reaction by light. Therefore, the difference in solubility between the exposed and unexposed areas in the developing solution during development is small, resulting in poor developability and unclear pattern edges.

[0003]

SUMMARY OF THE INVENTION The present invention was devised in view of the above-mentioned drawbacks of the prior art. The object of the present invention is a color which has good developability and is capable of forming a sharp edge pattern. It is to provide a colored paste for a filter.

[0004]

The object of the present invention is as follows.
A color characterized by a photosensitive composition containing a main component of an acrylic copolymer having a carboxyl group and an ethylenically unsaturated group in the side chain as a binder component, a coloring component, a polyfunctional monomer, and a photoinitiator. This is achieved with a colored paste for filters.

As the acrylic copolymer having a carboxyl group and an ethylenically unsaturated group in the side chain, an ethylenically unsaturated group is added to a polymer obtained by copolymerizing an unsaturated carboxylic acid and an ethylenically unsaturated compound. The thing added as a pendant is mentioned.

Examples of the unsaturated carboxylic acid used in the present invention include, but are not limited to, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, vinylacetic acid and acid anhydride. .

As the ethylenically unsaturated compound,
Methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate,
Isopropyl acrylate, n-propyl methacrylate,
Isopropyl methacrylate, n-butyl acrylate, n-butyl methacrylate, sec-butyl acrylate, sec-butyl methacrylate, iso-butyl acrylate,
Examples include iso-butyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, n-pentyl acrylate, n-pentyl methacrylate, styrene, p-methylstyrene, o-methylstyrene and m-methylstyrene. However, it is not limited to these.

Of these ethylenically unsaturated compounds, it is particularly preferable to use methyl methacrylate and styrene, and by incorporating these components as a copolymerization component of the acrylic copolymer, polymerization with good reproducibility is carried out. In addition, the coating film hardness can be increased.

Examples of the pendant having an ethylenically unsaturated group include vinyl group, allyl group, acryl group and methacryl group. As a method for adding such a pendant to a copolymer obtained by copolymerizing an unsaturated carboxylic acid and an ethylenically unsaturated compound, an ethylenically unsaturated compound having a glycidyl group in the carboxyl group or hydroxyl group side chain of the copolymer is used. A method of making a compound or an acrylic acid chloride by an addition reaction is general. In addition, a compound having an ethylenically unsaturated group can be added using isocyanate. Examples of the ethylenically unsaturated compound having a glycidyl group and acrylic acid chloride as referred to herein include glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, α-ethyl glycidyl acrylate,
Examples include crotonyl glycidyl ether, crotonic acid glycidyl ether, isocrotonic acid glycidyl ether, acrylic acid chloride methacrylic acid chloride, allyl chloride and methallyl chloride.

The addition amount of these ethylenically unsaturated compounds is 0.0 with respect to the carboxyl group of the acrylic copolymer.
A range of 5 to 0.8 equivalents is preferable, and a range of 0.
It is 1 to 0.6 equivalent. If the addition amount of the ethylenically unsaturated compound is less than 0.05 equivalent, the development allowance is narrow and the edge of the pattern is liable to be deteriorated. If the addition amount is more than 0.8 equivalent, the unexposed area is developed. The solubility of the liquid tends to be low and the hardness of the coating film tends to be low, and it is difficult to obtain a practical color filter.

The proportion of the acrylic copolymer having a carboxyl group and an ethylenically unsaturated group in the side chain contained in the binder component is preferably at least 5% by weight, more preferably 20% by weight or more. When the content of the acrylic copolymer is less than 5% by weight, the effect of expanding the development allowable width is small, and the developability is liable to be lowered, which makes it difficult to form a sharp edge portion pattern, which is not preferable.

As the coloring component, in addition to conventional organic and inorganic pigments, dyes and the like can be used alone or in combination.

Examples of polyfunctional monomers include bisphenol A diglycidyl ether acrylate, polyacrylate carbamate, modified bisphenol A epoxy acrylate, adipic acid 1,6-hexanediol acrylic acid ester, phthalic anhydride propylene oxide acrylic acid ester, and trimellitic acid diethylene glycol. Oligomer such as acrylic acid ester, rosin modified epoxy diacrylate, alkyd modified acrylate, and tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, bisphenol A diglycidyl ether diacrylate, trimethylolpropane triacrylate and pentaerythritol. Triacrylate etc. are mentioned. These can be used alone or in combination, and the monofunctional monomers as described below can be used in combination. They are, for example, ethyl acrylate, ethyl methacrylate, 2 ethylhexyl methacrylate, hydroxyethyl methacrylate, 2-ethylhexyl acrylate, n-butyl methacrylate, glycidyl methacrylate, lauryl acrylate, lauryl methacrylate, stearyl methacrylate, stearyl acrylate, isobornyl methacrylate, isobornyl acrylate. , Mixtures of two or more of these, or mixtures with other compounds.

As the photopolymerization initiator, known ones can be used, for example, α-aminoacetophenone, anthraquinone, benzoin ether, benzyl, benzophenone,
4,4'-bisdimethylaminobenzophenone, 4,
4'-bistrichloromethylbenzophenone, dibutylphenylphosphine, α, α-diethoxyacetophenone, 2-ethylanthraquinone, benzoinbisphenyl, chlorobenzophenone, benzoin, benzoin methyl ether, benzoin isobruether, anthraquinone oxanthone, methyl Examples include but are not limited to orthobenzoylbenzoic acid and paradimethylaminoacetophenone.

Further, para-dimethylaminobenzoic acid ester or the like can be used as a sensitization aid. Examples of other additives include polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, mono-t-butyl hydroquinone, catechol and picric acid, lubricants such as paraffin wax, and extenders such as silica and calcium carbonate. You may add an organic aluminum compound, an organic titanate compound, an organic zinc compound, an organic calcium compound, etc.

[0016]

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

Example 1 100 g of isopropyl alcohol was charged into a 1000 cc four-necked flask, and this was kept at 80 ° C. in an oil bath with nitrogen sealing and stirring while stirring with methyl methacrylate 3
0 g, styrene 40 g, and methacrylic acid 30 g were added with N.O. N-
2 g of azobisisobutyronitrile was mixed and this was added dropwise with a dropping funnel over 30 minutes. After continuing the reaction for 4 hours, 1 g of hydroquinone monomethyl ether was added, and then the temperature was returned to room temperature to complete the polymerization. The polymer A thus obtained was used. Next, 100 g of isopropyl alcohol was added to this polymer A,
While maintaining the temperature at 5 ° C, add 40 g of glycidyl methacrylate and 3 g of triethylbenzylammonium chloride, and add 3
Reacted for hours. Polymer B is obtained in this way.
And Here, the reaction rate of glycidyl methacrylate was 70% as determined from the change in the polymer acid value before and after the reaction. Therefore, the added amount was 0.73 equivalent. Furthermore, a paste having the composition shown below was prepared.

Polymer B 50% by weight Trimethylolpropane triacrylate 20% by weight α-aminoacetophenone 5% by weight Ethylene glycol monoethyl ether 200% by weight As a color pigment for this paste, red is Chromophtal red A2B + Seika Fast Yellow 2720 ( 7 /
3) 20% by weight, green is 18% by weight of green 2YN + Seika First Yellow 2720 (8/2), blue is 18% of cyanine blue E + violet RVS (7/3).
Weight% of each was added, and the pigment was dispersed by stirring for 30 minutes with a homomixer. The pigment paste thus obtained was pressure filtered with a 2μ filter and then applied to a glass plate with a spinner. After further prebaking at 80 ° C. for 10 minutes, pattern exposure was performed with a high pressure mercury lamp and development was performed with a 1% aqueous solution of sodium carbonate. Next, baking was performed at 200 ° C. for 30 minutes, and these steps were repeated three times to form a three-color mosaic pattern on the glass plate. As a result, with respect to developability, the unexposed area was dissolved in the developing solution in 5 seconds, and the exposed area was allowed to be dipped in the developing solution for 1 to 5 minutes to obtain a good pattern, and the edge portion of the pattern was sharp. It was

Example 2 100 g of isopropyl alcohol was charged into a 1000 cc four-necked flask, kept at 80 ° C. in an oil bath, sealed with nitrogen, and stirred with methyl methacrylate 1
0 g, styrene 60 g, and methacrylic acid 30 g have N.E. N-
2 g of azobisisobutyronitrile was mixed and this was added dropwise with a dropping funnel over 30 minutes. After continuing the reaction for 4 hours, 1 g of hydroquinone monomethyl ether was added, and then the temperature was returned to room temperature to complete the polymerization. The polymer C thus obtained was used. Next, after adding 100 g of isopropyl alcohol to this polymer C, add 7 g of this.
While maintaining the temperature at 5 ° C, add 40 g of glycidyl methacrylate and 3 g of triethylbenzylammonium chloride, and add 3
Reacted for hours. Polymer D is obtained in this way.
And Here, the reaction rate of glycidyl methacrylate was 70% as determined from the change in the polymer acid value before and after the reaction. Therefore, the added amount was 0.73 equivalent. The polymer thus obtained was made into a paste by the same method as in Example 1, and coating and patterning were evaluated. The unexposed area was dissolved in a developing solution in 5 seconds, and the exposed area was developed for 1 to 5 minutes. A good pattern was obtained even when immersed in the liquid, and the edge portion of the pattern was sharp.

Example 3 100 g of isopropyl alcohol was charged into a 1000 cc four-necked flask, and this was kept at 80 ° C. in an oil bath while nitrogen sealing and stirring were performed while methyl methacrylate 6 was added.
0 g, styrene 10 g, and methacrylic acid 30 g were added with N.E. N-
2 g of azobisisobutyronitrile was mixed and this was added dropwise with a dropping funnel over 30 minutes. After continuing the reaction for 4 hours, 1 g of hydroquinone monomethyl ether was added, and then the temperature was returned to room temperature to complete the polymerization. The polymer E was obtained as described above. Next, 100 g of isopropyl alcohol was added to this polymer E, and this was added to
While maintaining the temperature at 5 ° C, add 40 g of glycidyl methacrylate and 3 g of triethylbenzylammonium chloride, and add 3
Reacted for hours. Polymer F is obtained in this way.
And Here, the reaction rate of glycidyl methacrylate was 70% as determined from the change in the polymer acid value before and after the reaction. Therefore, the added amount was 0.73 equivalent. The polymer thus obtained was made into a paste by the same method as in Example 1, and coating and patterning were evaluated. The unexposed area was dissolved in a developing solution in 5 seconds, and the exposed area was developed for 1 to 5 minutes. A good pattern was obtained even when immersed in the liquid, and the edge portion of the pattern was sharp.

Example 4 A polymer was polymerized in the same manner as in Example 1 except that maleic acid was used instead of methacrylic acid in Example 1.
Similarly, when a color paste was prepared and evaluated, with respect to developability, the unexposed area was dissolved in the developing solution in 5 seconds, and the exposed area was in a developing solution for 1 to 5 minutes. Moreover, the edge portion of the pattern was sharp.

Example 5 A polymer was prepared in the same manner as in Example 1 except that glycidyl acrylate was used instead of glycidyl methacrylate, and a color paste was similarly prepared and evaluated. With regard to (1), the unexposed area was dissolved in the developing solution in 5 seconds, a good pattern was obtained even when the exposed area was immersed in the developing solution for 1 to 5 minutes, and the edge portion of the pattern was sharp.

Example 6 A polymer was prepared in the same manner as in Example 1 except that the amount of glycidyl methacrylate added in Example 1 was 20 g, and a color paste was similarly prepared and evaluated. With regard to (1), the unexposed area was dissolved in the developing solution in 5 seconds, a good pattern was obtained even when the exposed area was immersed in the developing solution for 1 to 5 minutes, and the edge portion of the pattern was sharp. At this time, the reaction rate of glycidyl methacrylate is 7
At 2%, the added amount was 0.38 equivalent.

Example 7 100 g of the polymer A of Example 1 was placed in a flask, which was sealed with nitrogen and agitated with methacrylic acid chloride 2 while stirring.
0 g is added dropwise in 30 minutes. At this time, the liquid temperature was kept at 15 ° C. by attaching it to a water bath filled with ice water so that the reaction temperature did not rise rapidly, and the reaction was carried out for 1 hour including the monomer dropping time. The polymer thus obtained was used in Example 1.
When a color paste was prepared and evaluated in the same manner as in 1., the unexposed area was dissolved in the developing solution in 5 seconds, and the exposed area was a pattern that could be left in the developing solution for 1 to 5 minutes. The edge of the pattern was sharp.

Comparative Example 1 A polymer was prepared and evaluated in the same manner as in Example 1 except that 100 g of the polymer A obtained in Example 1 was blended with 40 g of glycidyl methacrylate. The pattern flowed just by soaking for 30 seconds.

Comparative Example 2 A polymer was prepared and evaluated in the same manner as in Example 1 except that 1.95 g of glycidyl methacrylate was added and the addition reaction was carried out.
The coating film flowed just after soaking for 30 seconds. At this time, the reaction rate was 78% and the addition amount of glycidyl methacrylate was 0.0.
It was 4 equivalents.

[0027]

EFFECTS OF THE INVENTION By selecting an acrylic copolymer having an ethylenically unsaturated group and a carboxyl group in the side chain as a photosensitive polymer suitable for a color filter color paste, it is possible to obtain extremely excellent developability and sharp patterning. It was possible to make a good color filter as a result.

Claims (5)

[Claims] 1. A photosensitive composition comprising an acrylic copolymer having a carboxyl group and an ethylenically unsaturated group as a side chain as a main binder component, and a coloring component, a polyfunctional monomer and a photoinitiator. A colored paste for a color filter, characterized by: 2. The colored paste for a color filter according to claim 1, wherein the acrylic copolymer having a carboxyl group and an ethylenically unsaturated group contains at least styrene and methyl methacrylate as a copolymerization component. 3. The coloring for a color filter according to claim 1, wherein the amount of the ethylenically unsaturated group in the acrylic copolymer is 0.05 to 0.8 equivalent to the carboxyl group. paste. 4. A color paste for a color filter according to claim 1, wherein the binder component contains at least 5% by weight or more of an acrylic copolymer having a carboxyl group and an ethylenically unsaturated group in a side chain. . 5. The color filter according to claim 1, wherein the acrylic copolymer is obtained by adding an ethylenically unsaturated compound having a glycidyl group to an acrylic copolymer having a carboxyl group. Coloring paste.