JPH11174671A - Shading photosensitive composition and color filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately manufacture a resin black matrix at a low cost while easily forming a pattern of a thin film having high shading performance by setting a reflectance of a specified wavelength at a specified value, and setting an optical density OD550 in a specified range. SOLUTION: Reflectance at 550 nm is set at 4% or less, and optical density OP 550 is set at 3/μm-5/μm. As a photosensitive material to be a base, a well- known photosensitive resin such as a photo-polymerizing group obtained by combining acrylic monomer with a photo-polymerization initiator, a chemical amplifying group obtained by combining a photo acid generator couple with a cross-linking agent, a photosensitive resin using azide or diazo resin as a photosensitive material, optical dimerization type photosensitive material such as cinnamic acid or chalcone, and a photosensitive resin obtained by combining naptho quinone diazide with an alkaline soluble resin is used. A shading material, desirably, carbon black-containing ink is blended in the photosensitive resin by controlling the dispersion state thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-shielding photosensitive composition useful in the production of a black matrix of an optical color filter used for a color television, a liquid crystal display, a solid-state imaging device, a camera, etc. The present invention relates to a color filter having a formed black matrix.
More specifically, the present invention relates to a light-shielding photosensitive composition suitable for producing a black matrix having high image-forming properties while having high light-shielding properties, and a color filter having a high-precision, high light-shielding resin black matrix.

[0002]

2. Description of the Related Art Generally, a color filter forms a black matrix on the surface of a transparent substrate such as a glass or plastic sheet, and then sequentially forms three or more different hues, such as red, green and blue, in a stripe form. Alternatively, it is formed in a color pattern such as a mosaic shape. The pattern size varies depending on the use of the color filter and each color, but is about 5 to 700 μm. Further, the positional accuracy of the superposition is several μ to several tens μ, and it is manufactured by a fine processing technology with high dimensional accuracy.

[0003] Typical production methods of color filters include a dyeing method, a printing method, a pigment dispersion method, and an electrodeposition method.
Among these, in particular, a pigment dispersion method of forming a color filter image by coating a photopolymerizable composition containing a color material on a transparent substrate, repeating image exposure, development, and curing as necessary is a color filter. It is widely used because it has high accuracy such as pixel position and film thickness, has excellent durability such as light resistance and heat resistance, and has few defects such as pinholes.

The black matrix is generally arranged in a lattice, stripe, or mosaic pattern between red, green, and blue color patterns. Improving contrast by suppressing color mixture between the colors or malfunctioning of the TFT due to light leakage. Plays a role in preventing. For this reason, a high light-shielding property is required for the black matrix. Conventionally, a method of forming a black matrix with a metal film such as chromium has been generally used. In this method, a metal such as chromium is vapor-deposited on a transparent substrate and the chromium layer is etched through a photolithography process. Therefore, a high light-shielding property with a small thickness can be obtained with high accuracy. On the other hand, the method has a long manufacturing process and a low productivity, and has problems such as high cost and environmental problems due to waste liquid of the etching process.

For this reason, a method of forming a low-cost, pollution-free black matrix (resin black matrix) using a photosensitive resin in which a light-shielding pigment or dye is dispersed has been energetically studied. However, at present, the resin black matrix has not been put to practical use yet because of the problems described below. In order to achieve the same light-shielding properties (optical density) as a black matrix made of a metal film such as chromium in a resin black matrix, it is necessary to increase the content of a light-shielding pigment or dye or increase the film thickness. There is.

In the method of increasing the thickness, the flatness of the RGB colored pixels formed thereon is affected by the unevenness of the black matrix matrix. For this reason, the liquid crystal cell gap becomes non-uniform or the alignment of the liquid crystal is disturbed, thereby deteriorating the display capability. In addition, a problem such as disconnection of the transparent electrode ITO film provided on the color filter occurs. In addition, in the method of increasing the content of the light-shielding pigment and the dye, there is a problem that the sensitivity, developability, resolution, and adhesion of the photosensitive resin (black resist) are deteriorated. It is difficult to obtain the accuracy and reliability required for color filters.

That is, a photosensitive material excellent in image forming ability under a condition of a thin film and high light-shielding property has not been realized, which hinders the practical use of a resin black matrix.

[0008]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems and to provide a resist material having a sufficient image forming ability capable of easily forming a thin film and a pattern having a high light-shielding property by a photolithography method. This makes it possible to manufacture a resin black matrix of a color filter with high accuracy and at low cost. In addition, by using a black matrix as a resin, high quality color filters can be achieved,
It aims to eliminate pollution.

[0009]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that in a photosensitive composition containing a light-shielding material, the reflectance in the visible light region and the optical density OD are controlled within certain ranges. Has solved the above-mentioned object, and found that the resolution is particularly good, and that the image characteristics are good without generating fringes, and the present invention has been completed. That is, the present invention has a reflectivity at 550 nm of 4% or less, and
It is present in the light-shielding photosensitive composition having an optical density OD550 in the range of 3 / μm to 5 / μm. Further, the present invention relates to a color filter having a black matrix formed of a light-shielding photosensitive composition on a transparent substrate.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The photosensitive resin that forms the base of the light-shielding photosensitive composition includes a photopolymerization system combining an acrylic monomer and a photopolymerization initiator, a chemical amplification system combining a photoacid generator and a crosslinking agent, and azide or diazo as a photosensitive material. Known photosensitive resins such as a photosensitive resin using a resin, a photodimerizing photosensitive resin such as cinnamic acid or chalcone, and a photosensitive resin combining naphthoquinonediazide and an alkali-soluble resin can be used. The desired light-shielding photosensitive resin composition can be obtained by adding a light-shielding material whose dispersion state is controlled, preferably a carbon black-containing ink, to these various photosensitive resins.

The photopolymerizable photosensitive resin will be described in more detail, for example, a composition containing a binder resin, an acrylic monomer and a photopolymerization initiator. Examples of the binder resin include styrene monomers such as styrene, α-methyl-styrene, and vinyl toluene; unsaturated group-containing carboxylic acids such as acrylic acid, methacrylic acid, cinnamic acid, maleic acid, fumaric acid, maleic anhydride, and itaconic acid. Acid; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, allyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl ( Monomers such as (meth) acrylic acid esters such as meth) acrylate, benzyl (meth) acrylate, hydroxyphenyl (meth) acrylate, and methoxyphenyl (meth) acrylate Acrylic resins that. The binder resin preferably has a resin acid value in the range of 5 to 200 KOH · mg / g in terms of alkali developability, and from the viewpoint of coating properties, has a molecular weight of about 1,000 to 500,000 in terms of GPC in terms of polystyrene. Is preferably used.

As the acrylic monomer, for example, 1,
4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, neopentyl glycol diacrylate,
Tetraethylene glycol diacrylate, tripropylene glycol diacrylate, propylene glycol diacrylate, glycerin methacrylate acrylate, bisphenol A, ethylene oxide adduct diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, trimethylolpropane Compounds having two or more acryloyl groups in the molecule such as ethylene oxide-added triacrylate, glycerin propylene oxide-added triacrylate, trisacryloyloxyethylene phosphate, dipentaerythritol hexaacrylate, and the like can be given.
From the viewpoint of crosslinking efficiency, a compound having three or more acryloyl groups in a molecule is particularly preferably used.

As the photopolymerization initiator, a compound capable of generating a radical by actinic rays, for example, 2-
(4-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-methoxynaphthyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-ethoxy Halomethylated triazine derivatives such as naphthyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-ethoxycarbonylnaphthyl) -4,6-bis (trichloromethyl) -s-triazine, and halomethylated Oxadiazole derivatives, 2
-(2'-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (2'-chlorophenyl) -4,
5-bis (3'-methoxyphenyl) imidazole dimer, 2- (2'-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (2'-methoxyphenyl) -4,5-diphenyl Imidazole dimer, (4 ′
-Methoxyphenyl) -4,5-diphenylimidazole dimer and other imidazole derivatives, benzoin methyl ether, benzoin phenyl ether, benzoin isobutyl ether, benzoin isopropyl ether and other benzoins, benzoin alkyl ethers, 2-methylanthraquinone, 2-methylanthraquinone Ethyl anthraquinone, 2-t
-Anthraquinone derivatives such as -butylanthraquinone and 1-chloroanthraquinone, benzuanthrone derivatives, benzophenone, Michler's ketone, 2-methylbenzophenone, 3-methylbenzophenone, 4-methylbenzophenone, 2-chlorobenzophenone, 4-bromobenzophenone and 2-carboxybenzophenone Benzophenone derivatives such as 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 1-
Hydroxycyclohexylphenyl ketone, α-hydroxy-2-methylphenylpropanone, 1-hydroxy-1-methylethyl- (p-isopropylphenyl) ketone, 1-hydroxy-1- (p-dodecylphenyl)
Ketone, 2-methyl- (4 '-(methylthio) phenyl) -2-morpholino-1-propanone, 1,1,1-
Acetophenone derivatives such as trichloromethyl- (p-butylphenyl) ketone, thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2-
Thioxanthone derivatives such as chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone and 2,4-diisopropylthioxanthone;
Benzoic acid ester derivatives such as ethyl-dimethylaminobenzoate and ethyl p-diethylaminobenzoate; acridine derivatives such as 9-phenylacridine and 9- (p-methoxyphenyl) acridine; and phenazine derivatives such as 9,10-dimethylbenzphenazine. , Di-cyclopentadienyl-Ti-di-chloride, di-cyclopentadienyl-Ti-bis-phenyl, di-cyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluoro Phenyl-1-yl, di-cyclopentadienyl-Ti-
Bis-2,3,5,6-tetrafluorophenyl-1-yl, di-cyclopentadienyl-Ti-bis-2,4,
6-trifluorophenyl-1-yl, di-cyclopentadienyl-Ti-2,6-difluorophenyl-1-yl, di-cyclopentadienyl-Ti-2,4-di-fluorophenyl 1-yl, di-methylcyclopentadienyl-Ti-bis-2,3,4,5,6-pentafluorophenyl-1-yl, di-methylcyclopentadienyl-Ti-bis-2,6- Examples include titanocene derivatives such as di-fluorophenyl-1-yl and di-cyclopentadienyl-Ti-2,6-di-fluoro-3- (pyr-1-yl) -phenyl-1-yl.

In the case of a photopolymerizable photosensitive resin, an acrylic monomer is used in an amount of 10 to 2 with respect to 100 parts by weight of a binder resin.
Those in which the amount of the photopolymerization initiator is adjusted in the range of 0.5 to 20 parts by weight and the amount of the photopolymerization initiator in the range of 0.5 to 20 parts by weight are particularly preferably used.

The light-shielding photosensitive composition of the present invention can be obtained by blending a light-shielding material, preferably carbon black, with the above-described photosensitive resin. More specifically, a dispersant and a solvent are added to carbon black. In addition, for example, it can be obtained by blending a carbon black ink obtained by processing with a disperser such as a paint conditioner, a sand grinder, a ball mill, a roll mill, a stone mill, a jet mill, and a homogenizer.

Commercially available carbon black can be used as the light-shielding material. For example, the following grades can be used. Mitsubishi Chemical Corporation: MA7, MA8, MA11, MA1
00, MA220, MA230, # 52, # 50, # 4
7, # 45, # 2700, # 2650, # 2200, #
1000, # 990, # 900 manufactured by Degussa: Printex95, Printex 9
0, Printex85, Printex75, Pri
ntex55, Printex45, Printex4
0, Printex30, Printex3, Prin
texA, PrintexG, SpecialBlac
k550, SpecialBlack350, Spec
ialBlack250, SpecialBlack1
00

Manufactured by Cabot: Monarch 460,
Monarch 430, Monarch 280, Mon
arch120, Monarch800, Monarc
h4630, REGAL99, REGAL99R, RE
GAL415, REGAL415R, REGAL25
0, REGAL250R, REGAL330, BRAC
K PEARLS480, PEARLS130

Raven, manufactured by Colombian Carbon
11, RAVE15, RAVE30, RAVE3
5, RAVEN40, RAVEN410, RAVEN4
20, RAVE450, RAVE500, RAVE
N780, RAVEN850, RAVE890H, R
AVEN1000, RAVEN1020, RAVEN1
040 Among these carbon blacks, the average primary particle size is 150
nm or less, more preferably 120 nm or less is preferred because the desired reflectance is easily obtained. Further, the DBP oil absorption of carbon black is preferably from 10 to 100.
H is preferably 2 to 5.

As the dispersing agent, a surfactant having an affinity for carbon black, a pigment derivative, a polymer compound, or the like can be used. Among them, it is preferable to use a polymer compound as a dispersant since a desired reflectance can be easily obtained.

The solvent is not particularly limited as long as it can dissolve the photosensitive resin.
Organic solvents in the range of 0 ° C., for example, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether acetate, propylene glycol monoethyl ether, and the like are preferable because dispersion is easily controlled and a target reflectance is easily obtained. .

As the dispersion treatment, a treatment method suitable for fine dispersion using a sand mill or a paint shaker is preferable. As beads, glass beads or zirconia beads can be used, and the smaller the diameter of beads, the finer the particles can be dispersed. By keeping the temperature control at the time of dispersion constant, a result with good reproducibility can be obtained. The temperature at the time of dispersion is desirably set to 100 ° C. or less in order to prevent deterioration of the ink.

The reflectance can be controlled within the range of 4% or less by the above-described carbon black dispersion treatment.

The light-shielding photosensitive composition of the present invention contains carbon black as a light-shielding material in an amount of 35-70 wt%, preferably 35-70 wt%, based on the solid content of the light-shielding photosensitive resin, in order to achieve both high optical density and image characteristics. It is preferable that the content be in the range of 40 to 65% by weight.

It is preferable to mix a pigment or a dye other than carbon black as a light-shielding material from the viewpoint of obtaining a high OD, and it is preferable that the light-shielding material is substantially composed of carbon black. It is permissible to use an organic pigment such as a phthalocyanine derivative as long as the performance of the present invention is not impaired.

Next, the light-shielding photosensitive composition of the present invention will be described together with a method of applying the composition to a color filter. First,
The light-shielding photosensitive composition of the present invention is applied on a transparent substrate by a coating device such as a spinner, a wire bar, a flow coater, a die coater, a roll coater, a spray and the like, and dried. Then, a light-shielding black matrix image is formed by image exposure, development and, if necessary, heat curing or light curing through the photomask, and this operation is repeated for each of the three colored RGB photosensitive compositions to obtain a color filter. An image is formed. The transparent substrate used here is a transparent substrate for a color filter, and its material is not particularly limited.For example, polyester such as polyethylene terephthalate or polypropylene, polyolefin such as polyethylene, polycarbonate, polymethyl methacrylate, Examples include a thermoplastic plastic sheet of polysulfone, a thermosetting plastic sheet such as an epoxy resin, a polyester resin, and a poly (meth) acrylic resin, and various glass plates. Particularly, a glass plate and a heat-resistant plastic are preferably used from the viewpoint of heat resistance.

Such a transparent substrate is subjected to corona discharge treatment, ozone treatment, thin film treatment of various polymers such as a silane coupling agent or a urethane polymer in advance in order to improve physical properties such as surface adhesiveness. You can also. The coating method is not particularly limited, but the light-shielding photosensitive composition after coating and drying forms a resin black matrix, so that the film thickness is 0.1 to 2 μm, preferably 0.1 to 2 μm.
It is good to set it to 1.5 μ, more preferably 0.1 to 1 μ.

For drying, a hot plate, an IR oven, a convection oven, or the like can be used.
Preferred drying conditions are 40 to 150 ° C., and the drying time is 10 seconds to 60 minutes. In the present invention, the coating film formed from the light-shielding photosensitive composition thus obtained has a thickness of 550 nm.
Is required to be 4% or less, and the optical density (OD550) at 550 nm must be in the range of 3 to 5 per 1 μm of film thickness. When the reflectance exceeds 4%, the resolution is poor, and fringes are generated around the pattern, resulting in poor developability. The light source used for exposure for forming a resin black matrix or a colored pixel is, for example, a lamp light source such as a xenon lamp, a halogen lamp, a tungsten lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, a medium-pressure mercury lamp, and a low-pressure mercury lamp. And a laser light source such as an argon ion laser, a YAG laser, an excimer laser, and a nitrogen laser.

When only a specific wavelength of irradiation light is used, an optical filter can be used. The development process is not particularly limited as long as it is a solvent capable of dissolving the unexposed portion of the photosensitive composition film. For example, organic solvents such as acetone, methylene chloride, trichlene, and cyclohexanone can be used. However, many organic solvents have environmental pollution, harm to the human body, and danger of fire. Therefore, it is preferable to use an alkali developing solution having no such danger. Examples of such an alkaline developer include inorganic alkali agents such as sodium carbonate, potassium carbonate, sodium silicate, potassium silicate, sodium hydroxide, and potassium hydroxide, or diethanolamine, triethanolamine, and tetraalkylammonium hydroxide salts. And an aqueous solution containing an organic alkaline agent.

If necessary, the alkaline developer may contain a surfactant, a water-soluble organic solvent, a low molecular compound having a hydroxyl group or a carboxylic acid group, or the like. Especially,
It is preferable to add a surfactant because many surfactants have an effect of improving developability, resolution, background contamination and the like. For example, as a surfactant for a developer, an anionic surfactant having a sodium naphthalenesulfonate group, a sodium benzenesulfonate group, a nonionic surfactant having a polyalkyleneoxy group, a cation having a tetraalkylammonium group Surfactants and the like. There is no particular limitation on the development processing method,
Usually, it is carried out by a method such as immersion development, spray development, brush development, or ultrasonic development at a development temperature of 10 to 50 ° C, preferably 15 to 45 ° C.

[0030]

The present invention will be described in more detail with reference to the following examples and comparative examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention.

Synthesis Example-1 32 g of trimer of tolylene diisocyanate (Mitec GP750A manufactured by Mitsubishi Chemical Corporation, resin solid content 50 wt%, butyl acetate solution) and 0.02 g of dibutyltin dilaurate as a catalyst were mixed with propylene glycol monomethyl ether. It was diluted and dissolved with 47 g of acetate. 14.4 g of polyethylene glycol (manufactured by NOF Corporation, UNIOX M-1000) having a number-average molecular weight of 1,000 with one end being a methoxy group under stirring and a number-average molecular weight of 1,000
Polypropylene glycol (manufactured by Sanyo Chemical Industry Co., Ltd.)
After adding 9.6 g of a mixture of (Sanix PP-1000) dropwise, the mixture was further reacted at 70 ° C. for 3 hours. Next, N,
1 g of N-dimethylamino-1,3-propanediamine was added, and the mixture was further reacted at 40 ° C. for 1 hour. The amine value of the solution containing the dispersion resin thus obtained was determined by neutralization titration to be 14 mgKOH / g.
The resin content was determined by a dry-up method (the hot plate solvent was removed at 150 ° C. for 30 minutes and the resin concentration was calculated from the change in weight) to find that the resin content was 40 wt.
%Met.

Synthesis Example 2 20 g of a styrene-acrylic acid resin having an acid value of 200 and a weight average molecular weight of 5,000, 0.2 of p-methoxyphenol
g, dodecyltrimethylammonium chloride 0.2
g, propylene glycol monomethyl ether acetate (40 g) was charged into the flask, and (3,4-epoxycyclohexyl) methyl acrylate (7.6 g) was added dropwise.
The reaction was carried out at a temperature of 0 ° C. for 30 hours. The reaction solution was reprecipitated in water and dried to obtain a resin. When the neutralization titration with KOH was performed, the acid value of the resin was 80.

Examples 1-4 and Comparative Examples 1-2 Preparation of carbon black dispersed ink 50 parts by weight of carbon black described in Table 1, Synthesis Example
Propylene glycol monomethyl ether acetate was added at a ratio of 5 parts by weight of the dispersion resin shown in No. 1 to a solid content of 50 wt%. The weight of the dispersion was 50 g. This was well stirred by a stirrer to perform premixing. Next, dispersion treatment was performed for 6 hours at 25 to 45 ° C. using a paint shaker. As the beads, zirconia beads having a diameter of 0.5 mm were used, and the same weight as the dispersion was added. After the dispersion, the beads and the dispersion were separated by a filter.

Preparation of resist solution Using the above-described carbon black-dispersed ink, each component was added so that the solid content was as shown below, and the mixture was stirred and dissolved by a stirrer to prepare a black resist photosensitive solution.

[0035]

1) Composition of resist: Pigment carbon black (described in Table 1) 50 g Photopolymerization initiator system 2- (2-chlorophenyl) -4,5-diphenylimidazole dimer 2 g 4,4- ' Bis (diethylaminobenzophenone) 1 g Pentaerythritol tetrakisthiopropionate 2 g Binder resin (synthesized in Synthesis Example-2) 25 g Acrylic monomer: dipentaerythritol hexaacrylate 15 g Solvent Propylene glycol monomethyl ether acetate 300 g Polymer dispersant ( Synthesis Example-1) 5 g

2) Evaluation of resist A black resist photosensitive solution was applied to a glass substrate (7059, manufactured by Corning) using a spin coater, and dried on a hot plate at 80 ° C. for 1 minute. The thickness of the dried resist was measured by a stylus-type film thickness meter (α-step, manufactured by Tencor Corporation) and found to be 1 μm. The visible light reflectance of this sample was measured with a spectrophotometer (U-3500, manufactured by Hitachi, Ltd.). The reflectance was a numerical value at 550 nm. The OD was measured with a Macbeth densitometer (manufactured by Colmorgen). Next, this sample was exposed with a high-pressure mercury lamp at an exposure amount of 150 mj / cm ² through a resolution evaluation mask. It was immersed and developed in a potassium hydroxide aqueous solution having a temperature of 25 ° C. and a concentration of 0.05% for 1 minute. The minimum pattern obtained is 40
Observation was performed with an optical microscope of 0 magnification to evaluate the resolving power. At the same time, the presence or absence of fringes around the pattern was checked to determine the quality of the image characteristics.

[0037]

[Table 2]

[0038]

The light-shielding photosensitive composition of the present invention is a low-cost, high-quality resin black because it has high light-shielding properties in a thin film, but has good resolution, no fringe is generated in the pattern, and excellent image characteristics. A matrix can be formed. Since the color filter using the resin black matrix of the present invention is excellent in accuracy, flatness and durability, the display quality of the liquid crystal element can be improved more than before. Further, since the manufacturing process and the color filter itself do not contain harmful substances, the danger to the human body is reduced and the environmental safety is improved.

Claims (3)

[Claims] 1. A light-shielding photosensitive composition having a reflectance at 550 nm of 4% or less and an optical density OD550 in the range of 3 / μm to 5 / μm. 2. The light-shielding photosensitive composition according to claim 1, wherein the light-shielding material contained in the light-shielding photosensitive composition is substantially composed of carbon black. 3. A color filter having a black matrix formed of the light-shielding photosensitive composition according to claim 1 on a transparent substrate.