JP3374706B2 - Black photosensitive resin composition, color filter using the same, and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material for producing a color filter used for a liquid crystal display or the like, and more particularly to a method for forming a black matrix and a black photosensitive resin composition used therefor.

[0002]

2. Description of the Related Art Conventionally, color filters have been widely used in the field of liquid crystal display devices. This color filter usually has a plurality of color pixels of red, green, blue, etc. arranged on a transparent substrate. To obtain an image with better contrast, a black black matrix is formed between these pixels. In addition, TFT
It is also used for the purpose of preventing malfunction of the transistors used in the driving type liquid crystal display.

The black matrix described above is usually formed on a glass substrate by a metal thin film having a fine pattern in many cases. As a specific example, a method in which a metal or metal compound such as chromium or nickel is formed into a thin film by a vacuum film forming method such as a vapor deposition method or a sputtering method, and a fine pattern is formed by a photolithography method is generally used. Is.
Specifically, apply a photoresist on a thin film such as metal,
A resist pattern is formed by drying, irradiating ultraviolet rays through a photomask, and developing. Then, a black matrix is formed through an etching process and a resist stripping process. However, the black matrix manufactured in the above process has a problem that the manufacturing cost is very high due to the complexity of the process, and the cost of the color filter using the black matrix is also high.

When a color filter using this metal thin film is mounted on a transmissive liquid crystal display, the reflectance of the metal surface generally used as the metal thin film is high,
When strong external light enters the color filter, for example, in the case of a chrome thin film, there is a problem that the reflected light is strong and the display quality is remarkably deteriorated. On the other hand, various methods have been studied in order to improve the problems of the black matrix using the metal thin film as described above. For example, a method has been proposed in which carbon black and, if necessary, an organic pigment are dispersed in a photosensitive resin composition, and a black matrix is formed using this. However, in order to obtain sufficient light shielding properties with carbon black,
A film thickness of about 1 μm is required. For this reason, the overlapping portion with the pixels of a plurality of colors, which is the alignment margin, becomes a single protrusion, which causes display unevenness.

In Japanese Patent Application Laid-Open No. 6-59119, after a black photosensitive resin layer is provided on and between pixels of a plurality of colors,
A method and material have been proposed in which a black-black matrix is selectively provided only in gaps between pixels of a plurality of colors by exposing the entire surface from the substrate side using the pixels of a plurality of colors as a mask. When this so-called back exposure method is used, the black matrix and the colored pixels do not overlap each other, and a color filter having high flatness can be obtained. However, in order to obtain a sufficient thickness of the black-black matrix and prevent the black layer on the multi-color pixels from being completely removed by the developing solution or the like, the black photosensitive resin composition of the multi-color pixels should be formed. The light-shielding property in the photosensitive wavelength range had to be sufficiently high.

Particularly in the radical polymerization type photosensitive resin which is generally used, since the photosensitive characteristic curve is comparatively gentle and the γ value is small, a very high ultraviolet ray shielding ability is required in the colored pixel. . Therefore, it has been necessary to add an ultraviolet absorber such as titanium oxide, zinc oxide, a benzotriazole-based compound, or a coumarin-based compound to the colored pixels serving as a mask. As a result, there is a problem that the optical characteristics of the color filter, that is, the transparency and the contrast ratio are significantly impaired. further,
Carbon black has a property of capturing radicals generated from the photopolymerization initiator used in the photopolymerization photosensitive resin by irradiation of ultraviolet rays, and thus inhibits radical polymerization,
It was difficult to form sufficient pixels at an economical exposure amount, and there was a problem that the pattern peeled off during development.

Japanese Unexamined Patent Publication (Kokai) No. 4-177202 discloses a material for a black matrix comprising a binder polymer, a photo-acid generator, a cross-linking agent and a black pigment. This reaction system uses a conventional radical polymerization reaction. Unlike the above, it utilizes an acid-catalyzed reaction, and has the advantages of high sensitivity and high γ value. Therefore, the colored pixel does not need to have a high light-shielding property, an additive for an ultraviolet absorber is not necessary, and the sensitivity is high, so that the productivity is improved. However, when this resist reaction system is applied to the back exposure method, although sufficient sensitivity and film thickness can be obtained, just dispersing ordinary carbon causes the resin component to develop near the surface of the formed black matrix during development. Since it was eluted, the film strength was very weak, and there was the problem that almost no adhesion was obtained. However, by using the carbon black grafted with the polymer compound, the elution of the binder resin is suppressed and the adhesiveness is significantly improved.
However, in the moisture resistance test with the pressure cooker, sufficient adhesion could not be obtained. Further, when a polyhydroxystyrene homopolymer or a copolymer of polyhydroxystyrene / (meth) acrylic acid ester is used as a base resin for the binder resin, the solubility in an alkali developing solution is not sufficient, so that the colored pixel There was a problem that it remained on top.

[0008]

SUMMARY OF THE INVENTION The present invention solves the above problems of the prior art. The problem is to improve the adhesiveness after a moisture resistance test and to improve the adhesion of colored pixels on a developing pixel. It was made to reduce the residue, and it has a sufficient density to block light, can form a black matrix with low reflectance, and has high smoothness and high film strength. A black photosensitive resin composition that can be used, a color filter using the same, and a method for producing the same.

In order to achieve the above object in the present invention, first, in the invention of claim 1, the copolymer containing hydroxystyrene as a main component, the cross-linking agent, the photo-acid generator and the carbon black are made of a polymer compound. In the black photosensitive resin composition composed of grafted carbon which is grafted, the copolymer containing hydroxystyrene as a main component has a unit represented by the general formula 1 as a structural unit. Fifty
Mol% or more, 5 to 3 units represented by the general formula 2
Ri copolymer der containing 0 mol%, the addition amount of the crosslinking agent
Is 10 to 80% by weight with respect to the copolymer,
The addition amount of the agent is 1 with respect to the total amount of the copolymer and the crosslinking agent.
To 30% by weight in the range of black photosensitivity
It is a resin composition .

Further, in the invention of claim 2, in the grafted carbon black in which the carbon black is grafted with a polymer compound, the polymer compound is an aziridine group, an oxazoline group or an N-hydroxyalkyl group. An amide group, an epoxy group, a thioepoxy group, an isocyanate group, a vinyl group, an acrylic group, a methacrylic group, a silicon-based hydrolyzable group, a group having one or more groups selected from the amino group in the molecule , the amount thereof Is the carbo
The black photosensitive resin composition according to claim 1, wherein the content of the black photosensitive resin composition is in the range of 10 to 100% by weight .

Further, in the invention of claim 3, the carbon black has a pH of 7 or less, and the black photosensitive resin composition for a color filter according to the invention of claim 1 or 2.

According to a fourth aspect of the invention, there is provided a black matrix comprising the black photosensitive resin composition according to the first, second or third invention, and the black matrix and a plurality of colored pixels are provided. The color filter has no protrusions due to overlap.

Further, in the invention of claim 5, at least 1) a step of providing pixels of a plurality of colors on a transparent substrate, and 2) a pixel of the black photosensitive resin composition according to claim 1, 2 or 3 is a pixel of a plurality of colors. Steps provided above and between, 3) Step of exposing from transparent substrate side, 4) Step of heating, 5) Contact of liquid capable of dissolving black photosensitive resin composition on colored pixels with black photosensitive resin composition The method for producing a color filter according to claim 4, further comprising a step of dissolving and removing the black photosensitive resin composition on the pixels of a plurality of colors by performing the above.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. As the black photosensitive resin composition which becomes the black matrix, which is the black matrix, a black photosensitive resin composition comprising a resin material, a cross-linking agent, a photo-acid generator and polymer-grafted carbon black is used. The hydroxystyrene / acrylic acid or hydroxystyrene / methacrylic acid-based copolymer used in the present invention is a hydroxystyrene or hydroxystyrene derivative represented by the general formula 3 and an acrylic acid represented by the general formula 4. Alternatively, it can be obtained by copolymerizing with methacrylic acid. The copolymer of the present invention can be easily produced by an ordinary radical polymerization method. The content of the hydroxystyrene or hydroxystyrene derivative of Chemical formula 3 in the copolymer composition is preferably 50 mol% or more, and if it is less than 50%, sufficient sensitivity cannot be obtained. Further, the content of acrylic acid or methacrylic acid in Chemical formula 4 is 5 to 3
0 mol% is preferable, and if it is less than 5 mol%, the adhesion after the moisture resistance test is not sufficient. On the contrary, if it is more than 30%, the solubility is too high and peeling occurs during development. .

[0015]

[Chemical 3] (In the formula, R represents a methyl group or hydrogen)

[0016]

[Chemical 4] (In the formula, R'represents a methyl group or hydrogen)

Specific examples of the monomer represented by the above general formula 3 are p-hydroxystyrene and m-.
Examples thereof include hydroxystyrene, o-hydroxystyrene, α-methyl-4-hydroxystyrene and the like.

It is also possible to copolymerize another monomer as the third component. Specific examples of the third component monomer include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate. , N-pentyl methacrylate, isopentyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate, phenyl methacrylate,
Benzyl methacrylate, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate,
Sec-Butyl acrylate, t-butyl acrylate, n-pentyl acrylate, isopentyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, phenyl acrylate, acrylic Examples thereof include benzyl acid salt, 2-hydroxyethyl acrylate, and styrene.

As the cross-linking agent in the present invention, an N-alkoxymethyl compound can be used, and specifically, N-methoxymethylurea, N-butoxymethylurea, N-methoxymethylmelamine, N-butoxymethylmelamine, N- Methoxymethylguanamine, N-butoxymethylguanamine and the like can be mentioned. From the viewpoint of resolution and stability, it is preferable that the introduction rate of N-alkoxymethyl is as high as possible. Further, the addition amount of the crosslinking agent is preferably 10 to 80% by weight with respect to the resin. If the addition amount is less than 10% by weight, sufficient sensitivity cannot be obtained due to insufficient crosslinking, and if it is more than 80% by weight, a large amount of unreacted crosslinking agent remains, so that the solubility of the exposed area becomes poor. It is high, the sensitivity is also lowered, and the proportion other than carbon is increased, so that sufficient light shielding properties cannot be obtained.

As the photo-acid generator in the present invention, 40
Those having an absorption wavelength range of 0 nm or less are preferable, and 40
Those having a photosensitive region of 0 nm or more are not suitable for the present invention because the black resin remains on the colored pixels. Examples of the photoacid generator include trihalomethyl group-containing triazine derivatives and onium salts, and specific examples of trihalomethyl group-containing triazine derivatives include 2,4,6-tris (trichloromethyl) -s-triazine and 2- (P-Methoxystyryl) -4,6-bis (trichloromethyl) -s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxyphenyl)
-4,6-bis (trichloromethyl) -s-triazine, 2- (p-chlorophenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4'-methoxy-1'-naphthyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (p-methylthiophenyl) -4,6-bis (trichloromethyl) -s-triazine and the like can be used. As the onium salt, BF4-, PF6-, SbF6-, CF3SO of diaryliodonium or triarylsulfonium is used.
3-salt etc. are mentioned. These photoacid generators may be used alone or as a mixture, and the addition amount thereof is preferably 1 to 30% by weight based on the total amount of the resin and the crosslinking agent. This is because, if added in excess of 30% by weight, the amount of acid generated is too large and the acid diffuses into the unexposed area due to heating after the pattern exposure to cause a crosslinking reaction, resulting in a decrease in resolution. On the other hand, if the amount added is less than 1% by weight, the amount of acid generated is poor, the crosslinking reaction does not proceed sufficiently, and a pattern cannot be formed.

The polymer compound used for grafting the carbon black in the present invention has a group capable of easily reacting with a functional group present on the surface of carbon black. Specific examples of this group include an aziridine group, an oxazoline group, an N-hydroxyalkylamide group, an epoxy group, a thioepoxy group, an isocyanate group, a vinyl group, an acryl group, a methacryl group, a silicon-based hydrolyzable group, and an amino group. Examples of the polymer compound include
It is necessary that these groups have one kind or two or more kinds in the molecule. Particularly, in terms of reactivity with the functional group on the surface of carbon black, it is preferable to have one or more kinds of groups selected from aziridine group, oxazoline group, N-hydroxyalkylamide group, epoxy group, thioepoxy group and isocyanate group. Molecular compounds are preferred. More preferred is a polymer compound having one or more groups selected from an aziridine group, an oxazoline group and an N-hydroxyalkylamide group. When carbon black is reacted with a polymer compound, substances other than the polymer compound, such as polymer components, monomers and organic solvents, may be present in the reaction system as long as the reaction is not hindered. The polymer compound is 10 to 100% by weight of carbon black, preferably 20 to 60.
It is necessary to contain it by weight%. If it is less than 10% by weight, the effect of grafting, that is, the improvement of the film strength does not occur.
In the above case, the photosensitivity is impaired and the optical density is insufficient.

Further, as the above carbon black, p
H is 7 or less, and preferably 5 or less. If the pH is 7 or more, the effect of grafting, that is, the improvement of the film strength is not recognized.

The above materials are kneaded using a disperser such as a two-roll mill, a three-roll mill, a sand mill and a paint conditioner to obtain a black photosensitive resin composition. Further as a diluting solvent to improve workability during dispersion, ethyl cellosolve, ethyl cellosolve acetate, butyl cellosolve, butyl cellosolve acetate, ethyl carbitol, ethyl carbitol acetate, diglyme, cyclohexanone, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, You may use organic solvents, such as a lactate ester.

A color filter of the present invention using the above black photosensitive resin composition and a method for producing the same will be described below with reference to FIG.
It demonstrates based on an example of the process shown to (a)-(e). As shown in FIG. 1 (a), a plurality of colored pixels (2) are provided on a transparent substrate (1), and as shown in FIG. 1 (b), the black photosensitive resin composition of the present invention is provided therebetween. The product is uniformly applied onto the plurality of colored pixels (2) by a spinner method, a bar coating method, a roll coating method, a curtain coating method or the like to form a black resin layer (3).

As the method of forming the plurality of colored pixels (2), any of the currently practiced methods such as the conventional dyeing method, pigment dispersion method, printing method and electrodeposition method may be used. good.

Next, as shown in FIG. 1 (c), the back surface of the transparent substrate (1) is irradiated with ultraviolet light (4) for exposure to expose the black resin layer (3) in the gaps between the plural colored pixels (2). ) Only generate acid. As a light source used for this exposure, a high pressure mercury lamp, an ultra high pressure mercury lamp, or the like is used. When the photosensitive wavelength range of the black photosensitive resin composition extends to 400 nm or more,
It is preferable to expose through a visible light cut filter.

Next, as shown in FIG. 1D, the transparent substrate (1) containing the plurality of colored pixels (2) and the black resin layer (3) obtained above is heated at a temperature of 70 ° C to 130 ° C. By heating, the catalyst reaction of acid is used to cause a crosslinking reaction only in the gaps between the colored pixels (2) of the black resin layer (3). Temperature is 70
If the temperature is lower than ° C, the reaction does not proceed and sufficient sensitivity cannot be obtained. On the contrary, at 130 ° C or higher, the black resin layer (3) on the colored pixel (2) is also cured.

Next, as shown in FIG. 1 (d), the black resin layer (3) in the uncrosslinked portion on the colored pixel (2) is removed by using an alkaline developer, and the colored pixel (2) is removed. A color filter (A) having a black matrix between them is obtained. As the alkaline developer, an inorganic alkali such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium hydrogen carbonate or the like, or an organic alkali such as triethylamine, triethanolamine or tetramethylammonium hydroxide can be used. Further, in the alkaline developer, if necessary, other additives, for example,
You may add surfactant, a wetting agent, an organic solvent, etc.

[0029]

EXAMPLES The present invention will be specifically described below with reference to examples. <Example 1> [Synthesis of binder resin] p-hydroxystyrene 9
0.0 g (0.749 mol), acrylic acid 10.0 g
(0.139 mol) was dissolved in 100 ml of toluene and 250 ml of dioxane to prepare azoisobutyronitrile (0.1 ml).
After adding 5 g and reacting at 70 ° C. for 3 hours, the reaction solution was poured into hexane, and the obtained precipitate was dried under reduced pressure to 8
0.2 g of solid was obtained. From the result of NMR analysis, the copolymerization ratio of this resin was p-hydroxystyrene / acrylic acid = 79/21. In addition, the molecular weight is 10200 in terms of polystyrene and 4400 in number average molecular weight in terms of polystyrene by gel permeation chromatography analysis.
Met.

[Synthesis of Grafted Carbon] To a separable flask equipped with a stirring blade, an inert gas introduction tube, a reflux condenser, a thermometer, and a dropping funnel, 80 g of toluene and 20 g of methyl ethyl ketone were charged as a solvent, and methyl methacrylate (MMA) was added. ) 85 g, 2-hydrochiethylethyl methacrylate (HEMA) 15 g, thioglycolic acid 4.3 g, azobisisobutyronitrile (AIBN)
Polymerization was carried out by continuously dropping 2 g of the mixed solution over 4 hours. After heating at the same temperature for 3 hours, aging was carried out at 95 ° C. for 2 hours to complete the polymerization. Glycidyl methacrylate (G
MA) 8.5 g (1.3 times equivalent / COOH) as a catalyst, 1.3 g of tetrabutylammonium bromide, and as a polymerization inhibitor, hydroquinone monomethyl ether 0.1.
04g was added and it was made to react at reaction temperature 85-90 degreeC for 10 hours. This was reprecipitated in n-hexane, dried under reduced pressure at 50 ° C. for 2 days, and then one-end methacrylate type MMA-HE was used.
An MA copolymer macromonomer was obtained. 50 g of the macromonomer obtained here, 25 g of styrene (St), HEM
A 20 g, isopropenyl oxazoline (IPO) 5
g, AIBN 3 g as an initiator, and propylene glycol monomethyl ether acetate (PGM-
Ac) was dissolved in 100 g to obtain a polymerizable monomer composition. Further, 50 g of PGM-Ac was charged and the temperature was raised to 80 ° C. The above polymerizable monomer composition was charged into the dropping funnel and added dropwise for 3 hours while maintaining the temperature at 80 ° C., and then the polymerization reaction was continued at the same temperature for 2 hours. Then, the temperature was raised to 110 ° C. and the aging reaction was performed for 2 hours to obtain a solution of a polymer compound (nonvolatile content 40%) having an oxazoline group as a reactive group. 22.5 g of the polymer solution obtained here, 30 g of carbon black having a pH of 3, P
GM-Ac 97.5g and zirconia beads 800
3g at 100 ° C with stirring at 600 rpm.
Reacted for hours. After cooling, it was separated from the beads to obtain a carbon black graft polymer (GCB) dispersion having a carbon black content of 20%. G obtained here
To 150 g of CB dispersion, trimellitic anhydride (M
w192.13) 3.59 g, 1,8-diazabicyclo [5,4,0] -undecene (DBU) 0.
09 g, and reacted at a temperature of 80 ° C. for 1 hour,
A GCB dispersion containing carboxyl groups was obtained.

[Preparation of Black Photosensitive Resin Composition ] 300 g of GCB dispersion, p-hydroxystyrene / methacrylic acid copolymer as a binder resin (copolymerization ratio 7
9/21), 5 g of hexa (N-methoxymethyl) -melamine (manufactured by Sanwa Chemical Co., Ltd .: Nikkalac MW-30M) as a cross-linking agent, and 5 g of TAZ-104 manufactured by Midori Kagaku Co. as a photoacid generator. , PGM-Ac as solvent
172 g and 500 g of glass beads were put in a glass bottle and dispersed for 2 hours by a paint shaker to prepare a black photosensitive resin dispersion liquid.

[Formation of Black Resin Layer] As a transparent substrate (1) shown in FIG. 1 (a), Corning's "7059" is used as a substrate, and Fuji Hunt's "Color Mosaic CRY7000, CGY7000, CBV7000" is provided thereon. Was used to form RGB color patterns by a conventional method. The film thickness of these plural colored pixels (2) was 1.5 μm. This black photosensitive resin dispersion liquid was applied onto an RGB colored pattern obtained by forming a plurality of colored pixels (2) by a spinner at 760 rpm for 5 seconds and dried,
A black resin layer (3) as shown in (b) was formed. Subsequently, as shown in FIG. 1 (c), the entire surface was exposed from the transparent substrate (1) side with a 3 kW ultra-high pressure mercury lamp at an exposure dose of 160 mJ / cm ^{2 using} the plurality of colored pixels (2) as a mask. After exposure, it was heated at 90 ° C. for 1 minute using a hot plate. Using a 1.25% aqueous sodium hydroxide solution,
Development was performed for 30 seconds by a method of spraying a shower while rotating the substrate, and the black resin layer (3) in the non-exposed portion on the RGB colored pattern was removed. Finally 230 ° C in the oven
Then, as shown in FIG. 1 (e), a color filter (A) having a black resin layer (3) as a black matrix between the colored pixels (2) of RGB was obtained.

In the color filter (A) thus produced, no black resin layer (3) remained on the RGB colored pixel (2) pattern, and the black resin layer (black matrix ( 3) and the colored pixel (2) of RGB did not have a protrusion. Also, this color filter (A) was put in a pressure cooker tester, left for 50 hours under the conditions of 120 ° C, 100% RH and 2 atm, and then adhered by the cross-cut adhesion test method described in "JIS K 5400". As a result of evaluating the properties, the number of peeled black resin layers (3) was 0/100, and there was no problem in adhesion.

<Example 2> 95.0 g (0.791 mol) of p-hydroxystyrene and 5.0 g (0.0694 mol) of acrylic acid were dissolved in 100 ml of toluene and 250 ml of dioxane,
Add 0.5 g of azoisobutyronitrile and add 3 at 70 ℃
After reacting for a time, the reaction solution was poured into hexane, and the obtained precipitate was dried under reduced pressure to obtain 72.5 g of a solid. NM
From the result of R analysis, the copolymerization ratio of this resin was p-hydroxystyrene / acrylic acid = 88/12. Further, the molecular weight is 923 in terms of polystyrene by gel permeation chromatography analysis.
The number average molecular weight was 00 and the number average molecular weight was 4670. Using the thus synthesized p-hydroxystyrene / acrylic acid (copolymerization ratio 90/10) as a binder resin, GCB, a crosslinking agent, an acid generator and a solvent were mixed in the same manner as in Example 1. A black photosensitive resin composition was prepared. Further, it is applied on a glass substrate having an RGB pixel pattern, the entire surface is exposed from the back surface of the glass substrate, heated at 90 ° C. for 1 minute, developed, and finally heated at 230 ° C. for 1 hour, A color filter (A) having a black resin layer (3) as a black matrix between RGB colored pixels (2) was obtained.

In the color filter (A) thus obtained, no black resin layer (3) remains on the RGB colored pixels (2), and a black resin layer (black matrix) ( 3) and the colored pixel (2) of RGB did not have a protrusion. Further, in the evaluation of the adhesion of the color filter (A) by the pressure cooker tester, the number of peeled black resin layers (3) was 0.
It was / 100, and there was no problem in adhesion.

<Example 3> 80.0 g (0.666 mol) of p-hydroxystyrene and 20.0 g (0.232 mol) of methacrylic acid were added,
Dissolve in 100 ml of toluene and 250 ml of dioxane, add 0.5 g of azoisobutyronitrile, react at 70 ° C. for 3 hours, and then pour the reaction solution into hexane,
The obtained precipitate was dried under reduced pressure to obtain 76.7 g of solid. From the result of NMR analysis, the copolymerization ratio of this resin was p-
Hydroxystyrene / methacrylic acid = 75/25. The molecular weight was 8590 and the number average molecular weight was 4450 in terms of polystyrene by gel permeation chromatography analysis. Using the p-hydroxystyrene / methacrylic acid copolymer thus obtained as a binder resin, the same procedure as in Example 1 was repeated.
To prepare a black photosensitive resin composition, the black photosensitive resin sets
Using the product , a color filter (A) having a black resin layer (3) as a black matrix between the RGB colored pixels (2) was produced.

In the color filter thus obtained, no black resin layer (3) remained on the colored pixels (2) of RGB, and the black resin layer (3) forming the black matrix was obtained. There was no protrusion due to overlapping with the RGB colored pixel (2). Also in the evaluation of the adhesiveness of this color filter (A) using a pressure cooker tester, the number of peeled black resin layers (3) was 0/100, and there was no problem in the adhesiveness.

Example 4 p-Hydroxystyrene 70.0 g (0.583 mol), methacrylic acid 15.0 g (0.174 mol), n-butyl methacrylate 15.0 g (0.105 mol)
Was dissolved in 100 ml of toluene and 250 ml of dioxane, 0.5 g of azoisobutyronitrile was added, the mixture was reacted at 70 ° C. for 3 hours, and the reaction solution was poured into hexane.
The obtained precipitate was dried under reduced pressure to obtain 68.5 g of solid. From the result of NMR analysis, the copolymerization ratio of this resin was p-
Hydroxystyrene / acrylic acid / n-butyl methacrylate = 72/18/10. In addition, the molecular weight was 1800 in terms of polystyrene and 5100 in terms of number average molecular weight in terms of polystyrene by gel permeation chromatography analysis. The thus obtained p- hydroxystyrene / methacrylic acid copolymer used in the binder resin in the same manner as in Example 1, to prepare a black photosensitive resin composition <br/>, the black photosensitive resin Using the composition , RGB
A color filter (A) having a black resin layer (3) as a black matrix between the colored pixels (2) was prepared.

In the color filter thus obtained, no black resin layer (3) remained on the colored pixels (2) of RGB, and the black resin layer (3) forming the black matrix was obtained. There was no protrusion due to overlapping with the RGB colored pixel (2). Also, in the evaluation of the adhesion of this color filter by the pressure cooker tester, the number of peeled black resin layers (3) was 0 /.
It was 100, and there was no problem in adhesion.

<Comparative Example 1> 100 g (0.832 mol) of p-hydroxystyrene
Was dissolved in 100 ml of toluene and 250 ml of dioxane, 0.5 g of azoisobutyronitrile was added, the mixture was reacted at 70 ° C. for 3 hours, and the reaction solution was poured into hexane.
The obtained precipitate was dried under reduced pressure to obtain 70.6 g of p-hydroxystyrene polymer. In addition, the molecular weight is 13100 in terms of polystyrene and 490 in number average in terms of polystyrene by gel permeation chromatography analysis.
It was 0. Using the p-hydroxystyrene polymer thus obtained as a binder resin, a black photosensitive resin composition was prepared in the same manner as in Example 1. Next, on the glass substrate having the RGB pixel pattern, the black photosensitive
The resin composition was applied, the entire surface was exposed from the back surface of the glass substrate, heated at 90 ° C. for 1 minute, developed, and finally heated at 230 ° C. for 1 hour to obtain a color filter.

However, in the color filter obtained here, the black resin layer (3) remained on the RGB colored pixel (2) pattern and could not be completely dissolved and removed. Therefore, there was a protrusion due to the overlapping of the black resin layer (3) serving as the black matrix and the RGB colored pixel (2). It is considered that this is because the composition of the binder resin is a p-hydroxystyrene homopolymer and therefore the alkali dissolution is insufficient. Also in the evaluation of adhesion with a pressure cooker tester,
The number of peeled black resin layers (3) was 8/100, and the adhesion was incomplete.

Comparative Example 2 p-Hydroxystyrene 70 g (0.583 mol), acrylic acid 30 g (0.278 mol) and toluene 100
ml, dissolved in 250 ml of dioxane, added with 0.5 g of azoisobutyronitrile, reacted at 70 ° C. for 3 hours, poured into hexane, and the obtained precipitate was dried under reduced pressure to 80 Obtained 0.2 g of solid. From the result of NMR analysis, the copolymerization ratio of this resin was p-hydroxystyrene /
Acrylic acid = 60/40. Also, the molecular weight is
By gel permeation chromatography analysis, the weight average molecular weight was 18,200 and the number average molecular weight was 7,400 in terms of polystyrene. The p-hydroxystyrene / acrylic acid copolymer thus obtained (copolymerization ratio 62
/ 38) was used as the binder resin to prepare a black photosensitive resin composition in the same manner as in Example 1. Next, on the glass substrate having the RGB pixel pattern, the black photosensitive resin
The resin composition was applied, the entire surface of the glass substrate was exposed to light from the back surface, heated at 90 ° C. for 1 minute, and then developed. However, since the alkali solubility was too high at this stage, the black resin layer (3) was peeled off during the development, and the black matrix could not be formed.

<Comparative Example 3> 40 g (0.333 mol) of p-hydroxystyrene, 20 g (0.232 mol) of methacrylic acid, and n of methacrylic acid.
-Butyl 40 g (0.281 mol), toluene 100
ml, dioxane (250 ml), azoisobutyronitrile (0.5 g) was added, and the mixture was reacted at 70 ° C. for 3 hours, poured into hexane, and the obtained precipitate was dried under reduced pressure to obtain 62 Obtained 0.8 g of solid. From the result of NMR analysis, the copolymerization ratio of this resin was p-hydroxystyrene /
Methacrylic acid / n-butyl methacrylate copolymer = 43
It was / 25/32. In addition, the molecular weight is 10700 in terms of polystyrene and 4500 in terms of number average molecular weight in terms of polystyrene by gel permeation chromatography analysis.
Met. Using the thus obtained p-hydroxystyrene / methacrylic acid / n-butyl methacrylate copolymer (copolymerization ratio 43/25/32) as the binder resin, black sensitivity was obtained in the same manner as in Example 1 . A resin composition was prepared. Next, this black photosensitive resin composition was applied onto a glass substrate having an RGB pixel pattern, the entire surface was exposed from the back surface of the glass substrate, and after heating at 90 ° C. for 1 minute,
Development processing was performed. However, the exposure dose is 150 mJ / cm2
However, since the content of p-hydroxystyrene, which is a photo-crosslinking component, was low, the crosslinking reaction did not sufficiently occur, and it was dissolved during development. Although the black matrix can be formed by increasing the exposure amount to 500 mJ / cm 2, there is a problem that the sensitivity is significantly lowered and the productivity is lowered.

[0044]

The present invention, having the above-mentioned constitution, has the following effects. That is, a copolymer containing hydroxystyrene as a main component and an addition amount of 10 to 8 with respect to the copolymer.
The cross-linking agent in the range of 0% by weight , and the cross-linking agent and the copolymer
The photo-acid generator in an amount of 1 to 30% by weight based on the total amount and carbon black having a pH of 7 or less are contained in this carbon.
The black photosensitive resin composition composed of grafted carbon grafted with a polymer compound in an amount of 10 to 100% by weight based on the amount of black and black.
It has a high value and has excellent performance as a black matrix material for back exposure of color filters. However, by using a binder resin in which a monomer having a carboxylic acid is copolymerized, the cross-linking structure becomes strong and after a moisture resistance test. Since the adhesiveness is improved and the alkali solubility is further increased, the development residue on the colored pixel can be significantly reduced.

Further, according to the color filter manufacturing method of the present invention, it is possible to form a color filter in which the colored pixels and the black matrix made of the black photosensitive resin composition of the present invention do not overlap each other. Therefore, it is possible to significantly improve the display quality of the liquid crystal display device.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a side cross section of a manufacturing process of a color filter showing an embodiment of the invention, and FIG. 1A is a side cross section showing a colored pixel forming process. (B) is a side section showing a black photosensitive composition coating step. (C) is a side cross section showing a back surface exposure step. (D) is a side cross section showing a heat treatment process. (E) is a side cross section showing a development processing step.

[Explanation of symbols]

A: Color filter 1 ... Transparent substrate 2 ... Colored pixels 3 ... Black resin layer 4 ... UV light

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI G02B 5/22 G02B 5/22 G03F 7/004 503 G03F 7/004 503Z 505 505 7/033 7/033 (56) References Kaihei 4-177202 (JP, A) JP 9-124954 (JP, A) JP 6-67421 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03F 7 / 038 G03F 7/004 G03F 7/033 C08F 212/14 C08L 25/18 C08L 51/10 G02B 5/20 101 G02B 5/22

Claims (5)

(57) [Claims] 1. A black photosensitive resin composition comprising a copolymer having hydroxystyrene as a main component, a cross-linking agent, a photo-acid generator, and grafted carbon in which carbon black is grafted with a polymer compound. A copolymer containing hydroxystyrene as a main component has a structure represented by the general formula: The unit represented by the formula (wherein R represents a methyl group or hydrogen) is 50 mol% or more, and a unit represented by the general formula: (Wherein R 'represents a methyl group or hydrogen) Ri copolymer der containing 5-30 mol% of units represented by the cross-linking agent
The addition amount of 10 to 80% by weight with respect to the copolymer,
The addition amount of the photo-acid generator is the total amount of the copolymer and the cross-linking agent.
To 1 to 30% by weight in the range of black
Color photosensitive resin composition . 2. A grafted carbon black obtained by grafting the carbon black with a polymer compound, wherein the polymer compound is an aziridine group, an oxazoline group, an N-hydroxyalkylamide group, an epoxy group, a thioepoxy group, an isocyanate group. , vinyl group, acryl group, methacryl group, a silicon-based hydrolyzable group, also have one or two or more groups selected from amino groups in the molecule
Therefore, the amount is 10 to 10 with respect to the carbon black.
The range of 0% by weight according to claim 1.
Black photosensitive resin composition . 3. The black photosensitive resin composition according to claim 1, wherein the carbon black has a pH of 7 or less. 4. A black matrix comprising the black photosensitive resin composition according to claim 1, 2 or 3, and having no protrusions due to overlapping of the black matrix and a plurality of colored pixels. Color filter. 5. At least 1) a step of providing pixels of a plurality of colors on a transparent substrate, 2) a step of providing the black photosensitive resin composition according to claim 1, 2 or 3 on and between the pixels of a plurality of colors. 3) a step of exposing from the transparent substrate side, 4) a step of heating, 5) a liquid capable of dissolving the black photosensitive resin composition on the colored pixels is brought into contact with the black photosensitive resin composition, and thus on the multi-color pixels. The method for producing a color filter according to claim 4, further comprising a step of dissolving and removing the black photosensitive resin composition.