JP5162565B2 - Photosensitive coloring composition and color filter - Google Patents

Description

  The present invention relates to a photosensitive coloring composition used for manufacturing a color filter used for a color liquid crystal display device, a color image pickup tube element, and the like, and a color filter including a filter segment formed from the photosensitive coloring composition.

  The color filters that make up a liquid crystal display (LCD) are made by arranging two or more kinds of fine band (striped) filter segments of different hues in parallel or intersecting on the surface of a transparent substrate such as glass or the like. The filter segments are arranged in a constant arrangement. The filter segments are as fine as several microns to several hundreds of microns, and are regularly arranged in a predetermined arrangement for each hue.

In recent years, color liquid crystal display devices have formed a large market for liquid crystal color televisions, car navigation and liquid crystal display integrated laptops, and monitors and televisions for desktop computers that take advantage of energy and space saving features. As it has begun to spread. Although attention is paid to a display device that replaces a conventional CRT, the color reproduction characteristic of a liquid crystal display device is inferior to that of a CRT at present.
Therefore, there is an increasing demand for high color reproducibility in color filters in which filter segments for each color are arranged.

  In order to improve contrast, a black matrix is generally arranged between the filter segments of each color of the color filter. However, the material for forming this black matrix has recently become an environmental problem, low reflection, and low cost. In view of the above, attention is focused on a resin black matrix in which a light-shielding pigment is dispersed in a resin instead of a metal chromium black matrix. However, the resin black matrix has a problem that the light shielding property (optical density) is lower than that of the metal chromium black matrix.

In order to improve the color reproduction characteristics of the color filter and to improve the light shielding property of the black matrix, it is necessary to increase the content of the dye in the photosensitive coloring composition or to increase the film thickness. However, in the method of increasing the content of the dye, problems such as a decrease in sensitivity, developability and resolution are generated. In the method of increasing the film thickness, there is a problem that the exposure light does not reach the bottom of the film and the pattern shape becomes defective.
In order to solve such a problem, it is necessary to increase the sensitivity of the photosensitive coloring composition. Generally, (1) imparting a reactive double bond to the resin, (2) a photopolymerization initiator, A sensitizer is selected or increased, and (3) a monomer is selected or increased.

JP 2001-233842 A JP 2001-264530 A JP 2003-156842 A

However, improvement in sensitivity is limited only by the addition of a double bond to the resin and the selection of a photopolymerization initiator, a sensitizer, and a monomer. In particular, when the amount of the photopolymerization initiator is increased, coloring due to a color unique to the photopolymerization initiator, a decrease in heat resistance, a decrease in light transmittance, a decrease in resolution, and the like occur. Further, when the amount of the monomer is increased, problems such as tackiness occur.
Accordingly, an object of the present invention is to provide a photosensitive coloring composition having high sensitivity and excellent pattern shape even when the pigment content is high or the film thickness is large, and a color filter using the same. .

（式中、Ｒ₁〜Ｒ₄は、水素原子、Ｃ₁〜Ｃ₆のアルキル基、または置換基を有しても良いフェニル基を示す。） The photosensitive coloring composition of the present invention is characterized by using a photopolymerization initiator represented by the following formula (1) in order to obtain a high sensitivity and an excellent pattern shape. .
That is, a photosensitive coloring composition comprising a transparent resin and a dye carrier composed of a precursor thereof, a dye (excluding carbon black), a photopolymerization initiator represented by the following formula (1), and a sensitizer. The photosensitive coloring composition is characterized in that the sensitizer is 0.5 to 60% by weight based on the total amount of the photopolymerization initiator and the sensitizer.
Moreover, the color filter of this invention is a color filter which comprises the filter segment formed from the said photosensitive coloring composition.

(Wherein, R ₁ to R ₄ is a hydrogen atom, an alkyl group or an optionally substituted phenyl group, the C ₁ ~C _6.)

The photosensitive coloring composition of the present invention is a highly sensitive and excellent color filter by using a specific compound as a photopolymerization initiator, even if the pigment content is high or the thickness of each color filter segment is large. A segment can be formed.
Therefore, a high quality color filter can be obtained by using the photosensitive coloring composition of the present invention.

First, the photosensitive coloring composition in this invention is demonstrated concretely.
The photosensitive coloring composition of this invention contains the photoinitiator represented by the pigment | dye carrier which consists of transparent resin and its precursor, a pigment | dye, and said Formula (1).
The photopolymerization initiator represented by the above formula (1) has high sensitivity, and an excellent pattern-shaped filter segment can be formed by using a photosensitive coloring composition containing the photopolymerization initiator. Can do. In particular, the photopolymerization initiator is preferably a compound represented by the following formula (2).

In the photosensitive coloring composition of the present invention, other photopolymerization initiators can be used in combination with the compound represented by the above formula (1).
Other photopolymerization initiators include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, Acetophenone compounds such as 1-hydroxycyclohexyl phenyl ketone and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether Benzoin compounds such as benzyldimethyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl Benzophenone compounds such as 4′-methyldiphenyl sulfide, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2, Thioxanthone compounds such as 4-diisopropylthioxanthone and 2,4-diethylthioxanthone, 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2- ( p-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2-piperonyl-4,6- Bis (trichloromethyl) -s-triazine, 2,4-bis (tri (Loromethyl) -6-styryl-s-triazine, 2- (naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-methoxy-naphth-1-yl) -4 , 6-Bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, 2,4-trichloromethyl (4′-methoxystyryl) -6-triazine 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], O- (acetyl) -N- (1-phenyl-2-oxo-2- (4 ′ Oxime ester compounds such as -methoxy-naphthyl) ethylidene) hydroxylamine, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, 2,4,6 Phosphine compounds such as trimethylbenzoyldiphenylphosphine oxide, quinone compounds such as 9,10-phenanthrenequinone, camphorquinone, and ethylanthraquinone, borate compounds, carbazole compounds, imidazole compounds, titanocene compounds, and the like are used. . These photopolymerization initiators can be used alone or in combination.
The amount of the photopolymerization initiator used is preferably 0.5 to 50% by weight, more preferably 3 to 30% by weight, based on the total solid content of the photosensitive coloring composition.

Further, as sensitizers, triethanolamine, methyldiethanolamine, triisopropanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 2-dimethylaminoethyl benzoate, 2-Ethylhexyl 4-dimethylaminobenzoate, N, N-dimethylparatoluidine, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone, 4,4′-bis (ethylmethyl) Amine-based compounds such as amino) benzophenone can also be used in combination. These sensitizers can be used alone or in combination.
Among the sensitizers, 4,4′-bis (dimethylamino) benzophenone and 4,4′-bis (diethylamino) benzophenone are preferable, and 4,4′-bis (diethylamino) benzophenone is more preferable.
The amount of the sensitizer used is preferably 0.5 to 60% by weight, more preferably 3 to 40% by weight based on the total amount of the photopolymerization initiator and the sensitizer.

Further, the photosensitive coloring composition of the present invention can contain a polyfunctional thiol that functions as a chain transfer agent.
The polyfunctional thiol may be a compound having two or more thiol groups. For example, hexanedithiol, decanedithiol, 1,4-butanediol bisthiopropionate, 1,4-butanediol bisthioglycolate, ethylene Glycol bisthioglycolate, ethylene glycol bisthiopropionate, trimethylolpropane tristhioglycolate, trimethylolpropane tristhiopropionate, trimethylolpropane tris (3-mercaptobutyrate), pentaerythritol tetrakisthioglycolate, Pentaerythritol tetrakisthiopropionate, tris (2-hydroxyethyl) isocyanurate, trimercaptopropionic acid, 1,4-dimethylmercaptobenzene, 2,4,6-trimerca DOO -s- triazine, 2- (N, N- dibutylamino) -4,6-dimercapto -s- triazine. These polyfunctional thiols can be used alone or in combination.

  The amount of the polyfunctional thiol used is preferably 0.1 to 30% by weight, more preferably 1 to 20% by weight, based on the total solid content of the photosensitive coloring composition. If it is less than 0.1% by mass, the effect of adding a polyfunctional thiol is insufficient, and if it exceeds 30% by mass, the sensitivity is too high and the resolution is lowered.

  As described above, the dye carrier is composed of a transparent resin and a precursor thereof. The transparent resin is a resin having a transmittance of preferably 80% or more, more preferably 95% or more in the entire wavelength region of 400 to 700 nm in the visible light region. The transparent resin includes a thermoplastic resin, a thermosetting resin, and a photosensitive resin, and its precursor includes a monomer or an oligomer that is cured by irradiation with radiation to form a transparent resin. Or a mixture of two or more.

  Examples of the thermoplastic resin include butyral resin, styrene-maleic acid copolymer, chlorinated polyethylene, chlorinated polypropylene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyurethane resin, and polyester resin. , Acrylic resins, alkyd resins, polystyrene, polyamide resins, rubber resins, cyclized rubber resins, celluloses, polyethylene, polybutadiene, polyimide resins, and the like. Examples of the thermosetting resin include epoxy resins, benzoguanamine resins, rosin-modified maleic acid resins, rosin-modified fumaric acid resins, melamine resins, urea resins, and phenol resins.

  Examples of the photosensitive resin include (meth) acrylic compounds having a reactive substituent such as an isocyanate group, an aldehyde group, and an epoxy group on a linear polymer having a reactive substituent such as a hydroxyl group, a carboxyl group, or an amino group, A resin obtained by reacting an acid and introducing a photocrosslinkable group such as a (meth) acryloyl group or a styryl group into the linear polymer is used. Further, a linear polymer containing an acid anhydride such as a styrene-maleic anhydride copolymer or an α-olefin-maleic anhydride copolymer is converted into a (meth) acrylic compound having a hydroxyl group such as hydroxyalkyl (meth) acrylate. Half-esterified products are also used.

  Monomers and oligomers include methyl (meth) acrylate, ethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, cyclohexyl (meth) acrylate, β-carboxyethyl (meth) acrylate , Polyethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, triethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol Tri (meth) acrylate, 1,6-hexanediol diglycidyl ether di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, neo Pentyl glycol diglycidyl ether di (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tricyclodecanyl (meth) acrylate, ester acrylate, methylolated melamine (meth) acrylate, epoxy (meth) acrylate, urethane Various acrylates and methacrylates such as acrylates, (meth) acrylic acid, styrene, vinyl acetate, hydroxyethyl vinyl ether, ethylene glycol divinyl ether, pentaerythritol trivinyl ether, (meth) acrylamide, N-hydroxymethyl (meth) acrylamide , N-vinylformamide, acrylonitrile and the like. These can be used alone or in admixture of two or more.

  In the photosensitive coloring composition, the ratio M / P between the weight (P) of the transparent resin and the weight (M) of the precursor is preferably 0.10 to 1.20, and 0.15 to 1. 00 is more preferable, and 0.20 to 0.98 is particularly preferable. When the M / P is less than 0.10, the sensitivity is low, and when the M / P exceeds 1.20, a pattern-shaped linearity defect or tack is caused.

The ratio I _a / M of the weight (I _a ) of the photopolymerization initiator and the weight (M) of the precursor of the transparent resin is preferably 0.20 to 1.50, preferably 0.25 to 1 .40 is more preferable, and 0.30 to 1.30 is particularly preferable.

Further, when the photosensitive coloring composition contains a sensitizer, the ratio of the total weight (I _b ) of the photopolymerization initiator and the sensitizer to the weight (M) of the precursor of the transparent resin I _b / M is preferably 0.20 to 1.50, more preferably 0.25 to 1.40, and particularly preferably 0.30 to 1.30.
When I _a / M and I _b / M are less than 0.20, the sensitivity is low, and when I _a / M and I _b / M exceeds 1.50, a pattern-shaped linearity defect occurs.

  As a pigment | dye contained in the photosensitive coloring composition of this invention, an organic or inorganic pigment can be used individually or in mixture of 2 or more types. Among the pigments, pigments having high color developability and high heat resistance, particularly pigments having high heat decomposition resistance are preferable, and organic pigments are usually used.

Below, the specific example of the organic pigment which can be used for the photosensitive coloring composition of this invention is shown with a color index number.

  Examples of the red photosensitive coloring composition for forming the red filter segment include CI Pigment Red 7, 9, 14, 41, 48: 1, 48: 2, 48: 3, 48: 4, 81: 1, 81. : 2, 81: 3, 97, 122, 123, 146, 149, 168, 177, 178, 179, 180, 184, 185, 187, 192, 200, 202, 208, 210, 215, 216, 217, 220 Red pigments such as 223, 224, 226, 227, 228, 240, 246, 254, 255, 264, 272, and 279 can be used. A yellow pigment and an orange pigment can be used in combination with the red photosensitive coloring composition.

  For example, CI Pigment Yellow 1, 2, 3, 4, 5, 6, 10, 12, 13, 14, 15, 16, 17, 18 may be used as the yellow photosensitive coloring composition for forming the yellow filter segment. 20, 24, 31, 32, 34, 35, 35: 1, 36, 36: 1, 37, 37: 1, 40, 42, 43, 53, 55, 60, 61, 62, 63, 65, 73 74, 77, 81, 83, 86, 93, 94, 95, 97, 98, 100, 101, 104, 106, 108, 109, 110, 113, 114, 115, 116, 117, 118, 119, 120 123, 125, 126, 127, 128, 129, 137, 138, 139, 147, 148, 150, 151, 152, 153, 154, 155, 156, 161, 162, 164, 166 167,168,169,170,171,172,173,174,175,176,177,179,180,181,182,185,187,188,193,194,199,213,214, etc. Can be used.

Orange pigments such as CI Pigment orange 36, 43, 51, 55, 59, 61, 71, 73 can be used for the orange photosensitive coloring composition for forming the orange filter segment.
As the green photosensitive coloring composition for forming the green filter segment, for example, a green pigment such as CI Pigment Green 7, 10, 36, 37 can be used. A yellow pigment can be used in combination with the green photosensitive coloring composition.

  Blue photosensitive coloring compositions for forming blue filter segments include, for example, CI Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 22, 60, 64. , 80 and the like can be used. Purple pigments such as C.I. Pigment Violet 1, 19, 23, 27, 29, 30, 32, 37, 40, 42, and 50 can be used in combination with the blue photosensitive coloring composition.

For example, CI Pigment Blue 15: 1, 15: 2, 15: 4, 15: 3, 15: 6, 16, 81 or the like is used as a cyan photosensitive coloring composition for forming a cyan filter segment. Can be used.
For the magenta color photosensitive coloring composition for forming the magenta color filter segment, purple pigments and red pigments such as CI Pigment Violet 1, 19, CI Pigment Red 144, 146, 177, 169, 81 can be used. . A yellow pigment can be used in combination with the magenta photosensitive coloring composition.

Also, inorganic pigments include barium sulfate, zinc white, lead sulfate, yellow lead, zinc yellow, red bean (red iron (III) oxide), cadmium red, ultramarine, bitumen, chromium oxide green, cobalt green, amber, titanium black. Examples thereof include metal oxide powders such as synthetic iron black, titanium oxide, and iron tetroxide, metal sulfide powders, and metal powders. Inorganic pigments are used in combination with organic pigments in order to ensure good coatability, sensitivity, developability and the like while maintaining a balance between saturation and lightness.
The photosensitive coloring composition of the present invention may contain a dye within a range that does not reduce heat resistance for color matching.

  In the photosensitive coloring composition, the dye is sufficiently dispersed in the dye carrier, and is applied to a transparent substrate such as a glass substrate so that the dry film thickness is 0.2 to 5 μm to form a filter segment. A solvent can be included for ease. Examples of the solvent include cyclohexanone, ethyl cellosolve acetate, butyl cellosolve acetate, 1-methoxy-2-propyl acetate, diethylene glycol dimethyl ether, ethylbenzene, ethylene glycol diethyl ether, xylene, ethyl cellosolve, methyl-n amyl ketone, propylene glycol monomethyl ether toluene, methyl ethyl ketone. , Ethyl acetate, methanol, ethanol, isopropyl alcohol, butanol, isobutyl ketone, petroleum solvent and the like, and these are used alone or in combination.

  The photosensitive coloring composition is a three-roll mill, a two-roll mill, a sand mill, a kneader, an attritor, etc. in a dye carrier and a solvent together with the above-described photopolymerization initiator. It can be produced by finely dispersing using various dispersing means. Moreover, the photosensitive coloring composition containing 2 or more types of pigment | dyes can also mix and manufacture what each disperse | distributed finely in the pigment | dye carrier and a solvent separately. When the dye is dispersed in the dye carrier and the solvent, a dispersion aid such as a resin-type pigment dispersant, a surfactant, and a dye derivative can be appropriately contained. Since the dispersion aid is excellent in pigment dispersion and has a great effect of preventing re-aggregation of the pigment after dispersion, a photosensitive coloring composition obtained by dispersing the pigment in a dye carrier and a solvent using the dispersion aid is used. When used, a color filter excellent in transparency can be obtained.

  The resin-type pigment dispersant has a pigment-affinity part that has the property of adsorbing to the pigment and a part that is compatible with the dye carrier, and adsorbs to the pigment to stabilize the dispersion of the pigment on the dye carrier. It works. Specific examples of resin-type pigment dispersants include polycarboxylic acid esters such as polyurethane and polyacrylate, unsaturated polyamides, polycarboxylic acids, polycarboxylic acid (partial) amine salts, polycarboxylic acid ammonium salts, and polycarboxylic acid alkylamines. Salts, polysiloxanes, long-chain polyaminoamide phosphates, hydroxyl group-containing polycarboxylic acid esters, their modified products, amides formed by the reaction of poly (lower alkyleneimines) with polyesters having free carboxyl groups, and the like Water-based dispersants such as oily dispersants such as salts, (meth) acrylic acid-styrene copolymers, (meth) acrylic acid- (meth) acrylic acid ester copolymers, styrene-maleic acid copolymers, polyvinyl alcohol, polyvinylpyrrolidone Resin, water-soluble polymer, polyester Modified polyacrylate, ethylene oxide / propylene oxide addition compound, phosphate ester-based and the like are used, they can be used alone or in admixture of two or more.

  Surfactants include sodium lauryl sulfate, polyoxyethylene alkyl ether sulfate, sodium dodecylbenzene sulfonate, alkali salt of styrene-acrylic acid copolymer, sodium stearate, sodium alkyl naphthalene sulfonate, sodium alkyl diphenyl ether disulfonate. , Lauryl sulfate monoethanolamine, lauryl sulfate triethanolamine, ammonium lauryl sulfate, monoethanolamine stearate, sodium stearate, sodium lauryl sulfate, monoethanolamine of styrene-acrylic acid copolymer, polyoxyethylene alkyl ether phosphate Anionic surfactants such as: polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene Nonionic surfactants such as nylphenyl ether, polyoxyethylene alkyl ether phosphate ester, polyoxyethylene sorbitan monostearate, polyethylene glycol monolaurate; chaotic properties such as alkyl quaternary ammonium salts and their ethylene oxide adducts Surfactants: Examples include amphoteric surfactants such as alkylbetaines such as alkyldimethylaminoacetic acid betaine and alkylimidazolines, and these can be used alone or in admixture of two or more.

  The dye derivative is a compound in which a substituent is introduced into an organic dye, and the organic dye includes naphthalene-based and anthraquinone-based light yellow aromatic polycyclic compounds that are not generally called dyes. Examples of the dye derivatives are described in JP-A-63-305173, JP-B-57-15620, JP-B-59-40172, JP-B-63-17102, JP-B-5-9469, and the like. These can be used alone or in combination of two or more.

  The photosensitive coloring composition can contain a storage stabilizer in order to stabilize the viscosity of the composition with time, and an adhesion improver such as a silane coupling agent in order to improve the adhesion to the transparent substrate. Can also be included. Examples of storage stabilizers include quaternary ammonium chlorides such as benzyltrimethyl chloride and diethylhydroxyamine, organic acids such as lactic acid and oxalic acid, and organic acids such as methyl ether, t-butylpyrocatechol, tetraethylphosphine, and tetraphenylphosphine. Examples thereof include phosphine and phosphite.

  Examples of the silane coupling agent include vinyl silanes such as vinyltris (β-methoxyethoxy) silane, vinylethoxysilane, and vinyltrimethoxysilane, (meth) acrylsilanes such as γ-methacryloxypropyltrimethoxysilane, β- (3 , 4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) methyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, β- (3,4-epoxycyclohexyl) ) Epoxysilanes such as methyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β ( Aminoethyl) γ-aminopro Lutriethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N Examples include aminosilanes such as -phenyl-γ-aminopropyltriethoxysilane, thiosilanes such as γ-mercaptopropyltrimethoxysilane, and γ-mercaptopropyltriethoxysilane.

The photosensitive coloring composition can be prepared in the form of a solvent developing type or alkali developing type colored resist material. The colored resist material is obtained by dispersing a pigment in a composition containing a thermoplastic resin, a thermosetting resin or a photosensitive resin, a monomer, a photopolymerization initiator, and a solvent.
The pigment is preferably contained in a proportion of 5 to 70% by weight based on the total solid content of the photosensitive coloring composition. More preferably, it is contained in a proportion of 20 to 50% by weight, and the remainder consists essentially of a resinous binder provided by a dye carrier.

  The photosensitive coloring composition is obtained by means of centrifugal separation, sintering filter, membrane filter or the like, coarse particles of 5 μm or more, preferably coarse particles of 1 μm or more, more preferably coarse particles of 0.5 μm or more and mixed dust. Is preferably removed.

Next, the color filter in the present invention will be described.
The color filter of the present invention is provided with a filter segment formed from the photosensitive coloring composition of the present invention on a transparent substrate, and a general color filter has at least one red filter segment and at least one green color. A filter segment and at least one blue filter segment, or at least one magenta filter segment, at least one cyan filter segment, and at least one yellow filter segment.

As the transparent substrate, glass plates such as soda lime glass, low alkali borosilicate glass and non-alkali alumino borosilicate glass, and resin plates such as polycarbonate, polymethyl methacrylate, and polyethylene terephthalate are used. In addition, a transparent electrode made of indium oxide, tin oxide, or the like may be formed on the surface of the glass plate or the resin plate in order to drive the liquid crystal after forming the panel.
The dry film thickness of the filter segment is preferably 0.2 to 10 μm, more preferably 0.2 to 5 μm. When drying the coating film, a vacuum dryer, a convection oven, an IR oven, a hot plate, or the like may be used.

  The formation of each color filter segment by photolithography is performed by the following method. That is, the photosensitive coloring composition prepared as a solvent developing type or alkali developing type colored resist material has a dry film thickness of 0. 0 on a transparent substrate by a coating method such as spray coating, spin coating, slit coating or roll coating. It apply | coats so that it may become 2-10 micrometers. If necessary, the dried film is exposed to ultraviolet light through a mask having a predetermined pattern provided in contact with or non-contact with the film. Thereafter, the filter segment can be formed by immersing in a solvent or an alkaline developer, or spraying the developer with a spray or the like to remove the uncured portion to form a desired pattern. Furthermore, in order to accelerate the polymerization of the colored resist material, heating can be performed as necessary. According to the photolithography method, a filter segment with higher accuracy than the printing method can be formed.

In development, an aqueous solution such as sodium carbonate or sodium hydroxide is used as an alkali developer, and an organic alkali such as dimethylbenzylamine or triethanolamine can also be used. Moreover, an antifoamer and surfactant can also be added to a developing solution.
As a development processing method, a shower development method, a spray development method, a dip (immersion) development method, a paddle (liquid accumulation) development method, or the like can be applied.
In order to increase the UV exposure sensitivity, the colored resist material is applied and dried, and then a water-soluble or alkali-soluble resin such as polyvinyl alcohol or water-soluble acrylic resin is applied and dried to form a film that prevents polymerization inhibition by oxygen. Then, ultraviolet exposure can be performed.

Hereinafter, the present invention will be described more specifically by way of examples. However, the present invention is not limited to the following examples unless it exceeds the gist.
In the examples and comparative examples, “parts” means “parts by weight”.
First, preparation of acrylic resin solutions used in Examples and Comparative Examples will be described. The molecular weight of the resin is a weight average molecular weight in terms of polystyrene measured by GPC (gel permeation chromatography).

[Preparation of acrylic resin solution]
A reaction vessel was charged with 800 parts of cyclohexanone, heated to 100 ° C. while injecting nitrogen gas into the vessel, and a mixture of the following monomer and thermal polymerization initiator was added dropwise at the same temperature over 1 hour to carry out a polymerization reaction.
Styrene 60.0 parts Methacrylic acid 60.0 parts Methyl methacrylate 65.0 parts Butyl methacrylate 65.0 parts Azobisisobutyronitrile 10.0 parts After dropping and further reacting at 100 ° C. for 3 hours, azobisisobuty A solution prepared by dissolving 2.0 parts of nitrile in 50 parts of cyclohexanone was added, and the reaction was further continued at 100 ° C. for 1 hour to obtain an acrylic resin solution. The weight average molecular weight of the acrylic resin was about 40,000.
After cooling to room temperature, about 2 g of the resin solution was sampled, heated and dried at 180 ° C. for 20 minutes to measure the nonvolatile content, and cyclohexanone was added to the previously synthesized resin solution so that the nonvolatile content was 20% by weight. To prepare an acrylic resin solution.

[Adjustment of red pigment dispersion]
A mixture having the following composition was uniformly stirred and mixed, dispersed with a sand mill for 5 hours using glass beads having a diameter of 1 mm, and then filtered with a 5 μm filter to prepare a red pigment dispersion.
Diketopyrrolopyrrole pigment (CI Pigment Red 254) 10.0 parts ("Irga Four Red B-CF" manufactured by Ciba Geigy)
1.6 parts of anthraquinone pigment (CI Pigment Red 177) (“Chromophthal Red A2B” manufactured by Ciba Geigy)
0.4 parts of anthraquinone pigment (CI Pigment Yellow 199) (“Chromotal Yellow GT-AD” manufactured by Ciba Geigy)
Dispersant (“Solsperse 20000” manufactured by Zeneca) 2.4 parts acrylic resin solution 28.0 parts cyclohexanone 57.6 parts

[Adjustment of green pigment dispersion]
A green pigment dispersion was prepared in the same manner as the red pigment dispersion except that the pigment was changed to the following pigment.
7.0 parts of halogenated copper phthalocyanine pigment (CI Pigment Green 36) (“Lionol Green 6YK” manufactured by Toyo Ink Co., Ltd.)
Monoazo pigment (CI Pigment Yellow 150) 5.0 parts ("Funchon First Yellow Y-5688" manufactured by Bayer)

[Example 1 and Comparative Examples 1 and 2] (Preparation of photosensitive coloring composition)
With the blending composition shown in Table 1, the mixture was stirred and mixed to be uniform, and then filtered through a 1 μm filter to obtain each color resist material.

Monomer: Trimethylolpropane triacrylate (Shin Nakamura Chemical Co., Ltd. “NK ester ATMPT”)
Photopolymerization initiator A: Compound represented by the formula (2) Photopolymerization initiator B: 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime]
("Irgacure OXE01" manufactured by Ciba Specialty Chemicals)
Photopolymerization initiator C: 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1
("Irgacure 369" manufactured by Ciba Specialty Chemicals)
Sensitizer: 4,4′-bis (diethylamino) benzophenone (“EAB-F” manufactured by Hodogaya Chemical Co., Ltd.)
Multifunctional thiol: Trimethylolpropane tristhiopropionate Solvent: Cyclohexanone

[Filter segment pattern formation]
The obtained resist material was applied to a 10 cm × 10 cm glass substrate by spin coating so that the film thickness after post-baking was as shown in Table 2, and then pre-baked at 70 ° C. for 15 minutes in a clean oven. did. Next, after cooling the substrate to room temperature, ultraviolet rays were exposed through a photomask using an ultrahigh pressure mercury lamp. Thereafter, the substrate was spray-developed using a sodium carbonate aqueous solution at 23 ° C., washed with ion-exchanged water, and air-dried. Thereafter, post-baking was performed at 230 ° C. for 30 minutes in a clean oven to form striped filter segments on the substrate.

[Evaluation]
The sensitivity of the obtained resist material and the pattern shape of the filter segment formed by the above method were evaluated by the following methods. The results are shown in Table 2.
(sensitivity)
The sensitivity of the resist was determined by the irradiation exposure amount at which the pattern of the formed filter segment was finished according to the image size of the photomask. The rank of evaluation is as follows.
○: Less than 100 mJ / cm ² Δ: 100 mJ / cm ² or more and less than 300 mJ / cm ² ×: 300 mJ / cm ² or more

(Pattern shape)
The shape of the pattern of the formed filter segment was evaluated by (1) the linearity of the pattern and (2) the cross-sectional shape of the pattern.
(1) was evaluated by observing with an optical microscope. The rank of evaluation is as follows.
◯: Good linearity Δ: Partially good linearity x: Poor linearity (2) was evaluated by observing with a scanning electron microscope (SEM). The rank of evaluation is as follows.
○: Forward tapered shape.
Δ: Non-tapered shape.
X: Reverse taper shape.

  As shown in Table 2, Example 1 in which the compound represented by the formula (2) was used as a photopolymerization initiator had high sensitivity, and the obtained pattern had good linearity and cross-sectional shape. On the other hand, in Comparative Examples 1 and 2 using other photopolymerization initiators, any of sensitivity, pattern linearity, and cross-sectional shape is poor, and all of them are not good. It was.

Claims (7)

A photosensitive coloring composition comprising a dye carrier comprising a transparent resin and a precursor thereof, a dye (excluding carbon black), a photopolymerization initiator represented by the following formula (1), and a sensitizer, What 0.5-60 wt% der the total amount of the sensitizer is a photopolymerization initiator and a sensitizer as a reference, and the content of the dye, 20 to total solids of the photosensitive coloring composition based The photosensitive coloring composition characterized by being -50 wt% .

(Wherein, R ₁ to R ₄ is a hydrogen atom, an alkyl group or an optionally substituted phenyl group, the C ₁ ~C _6.)   Sensitizers are triethanolamine, methyldiethanolamine, triisopropanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 2-dimethylaminoethyl benzoate, 4- 2-ethylhexyl dimethylaminobenzoate, N, N-dimethylparatoluidine, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone, 4,4′-bis (ethylmethylamino) The photosensitive coloring composition according to claim 1, which is any one selected from the group consisting of benzophenone. The photosensitive coloring composition according to claim 1 or 2, wherein the photopolymerization initiator is a compound represented by the following formula (2).

The photosensitive coloring composition according to any one of claims 1 to 3, wherein the ratio between the weight (P) of the transparent resin and the weight (M) of the precursor is in the following relationship.
M / P = 0.10-1.20 The photosensitive coloring composition according to any one of claims 1 to 4, wherein the ratio of the weight (I _a ) of the photopolymerization initiator and the weight (M) of the precursor of the transparent resin has the following relationship: object.
I _a /M=0.20-1.50 5. The ratio of the total weight (I _b ) of the photopolymerization initiator and the sensitizer to the weight (M) of the precursor of the transparent resin is in the following relationship: 5. Photosensitive coloring composition.
I _b /M=0.20-1.50 A color filter comprising a filter segment formed from the photosensitive coloring composition according to any one of claims 1 to 6 on a transparent substrate.