JP2011112691A - Color filter and photosensitive colored resin composition used for the same - Google Patents

Abstract

To provide a color filter having excellent flatness without providing a protective layer and without polishing.
A colored photosensitive composition having a different blending ratio for each color is used, and a horn level difference 6 formed by overlapping a black matrix 3 and a colored layer 4 is set to 0.1 μm to 0.4 μm. For example, in the red photosensitive composition, the ratio of the resin and the compound having an unsaturated double bond (compound / resin having an unsaturated double bond) is 0.3 or more and 0.4 or less, and the unsaturated double bond is The ratio of the compound having a bond to the photopolymerization initiator (photopolymerization initiator / compound having an unsaturated double bond) is 0.15 or more.
[Selection] Figure 2

Description

  The present invention relates to a color filter excellent in flatness and a photosensitive colored resin composition used therefor. The color filter of the present invention can be applied to, for example, a liquid crystal display panel.

  Color liquid crystal display panels are rapidly spreading mainly in computer terminal display devices and television image display devices. The color filter is an indispensable important component for color display of a liquid crystal display panel. In recent years, this liquid crystal display panel has a high demand for high image quality, and various new types of liquid crystal display panels having a high viewing angle and high-speed response have appeared. Among them, a liquid crystal display panel in which a liquid crystal and a polymerizable composition are sealed between two substrates, and the alignment is fixed by irradiating the liquid crystal display panel containing the liquid crystal and the polymerizable composition with light. The liquid crystal display [PSA (polymer-stained alignment: polymer maintaining alignment)] defines the pretilt direction without the need for rubbing treatment, and therefore has excellent alignment stability and high-speed response of the liquid crystal molecules. Since it is simplified, the contrast becomes very good. Therefore, it is a method that is widely used because of its excellent display quality.

  A color filter, which is one of the members used for a liquid crystal display panel, includes a transparent substrate, a black matrix having an opening provided on the transparent substrate, and a colored layer constituting a color pixel provided in the opening. And have. In order to prevent light leakage from the gap between the colored layer and the black matrix when misalignment occurs during the formation of the colored layer, the end portion of the colored layer overlaps the black matrix. However, when the end of the colored layer is formed so as to overlap the black matrix, a film bulge called a horn step occurs in the colored portion overlapping the black matrix. Usually, when the horn step is large, display defects such as disordered alignment of the liquid crystal are remarkably brought. In particular, since a liquid crystal display panel using the PSA method does not require rubbing, it is considered that the horn step of the color filter significantly affects the display quality.

  In addition, along with the improvement in image quality of liquid crystal display panels, pixel dots are becoming finer in color filters, such as improvements in aperture ratio, mobile terminal use, and higher definition. As a result, the black matrix is becoming thinner. Yes. For this reason, when the amount of overlap increases, color overlap of the colored filter layer occurs, and the horn step further increases. For this reason, there is a demand for a color filter having a low step difference even when a high-definition black matrix is used.

  Conventionally, as a method of reducing the horn step, it has been common to provide a protective layer (overcoat layer) made of a transparent resin on the colored layer to flatten the step between adjacent pixels or the step between the black matrix and the colored layer. (FIG. 1).

  However, with the recent widespread use of liquid crystal display panels, there is an urgent need to reduce the cost of color filters. Therefore, as one of the cost reductions of the color filter, a color filter having a configuration without a protective layer is desired.

  At present, as a method for flattening a step between a black matrix and a pixel without providing a protective layer, the surface of a color filter substrate is polished as in Patent Document 1.

However, the color layer of the color filter substrate is very soft because it is formed of pigments or dyes. Therefore, when such polishing is performed, many scratches are generated by the polishing, and the display quality may be greatly impaired. In addition, the polishing increases the number of new manufacturing steps and increases the cost. Therefore, it is important to flatten the surface of the color filter substrate without polishing.

  As a method of reducing this horn step without polishing, a method disclosed in Patent Documents 2 to 3 as an approach from the black matrix side (a method by improving the shape of the black matrix or a method of reducing the thickness thereof) There is. However, the shape of the black matrix as in Patent Documents 2 to 3 is difficult to make a thin line and cannot be used for high-definition display. Further, as an approach from the coloring composition side, Patent Document 4 discloses a method of setting the molecular weight and glass transition temperature (Tg) of a resin contained in the coloring composition within a certain range. However, the method disclosed in Patent Document 3 greatly changes the material and characteristics, leading to an increase in cost. Therefore, a method for making the horn step as low as possible with simpler adjustment is desired.

JP 2006-334737 A JP-A-6-331815 JP 2008-58729 A JP 2006-284660 A

  An object of the present invention is to provide a color filter having excellent flatness without providing a protective layer and without polishing. In addition, another object is to provide a photosensitive colored resin composition capable of producing the color filter. This color filter can be suitably applied to a PSA liquid crystal display panel.

That is, the invention according to claim 1 is a liquid crystal display panel in which a liquid crystal and a polymerizable composition are sealed between two substrates, and the liquid crystal display panel including the liquid crystal and the polymerizable composition is irradiated with light. In the color filter used for the liquid crystal display panel that fixes the orientation,
The color filter is characterized in that the step formed by the overlap of the black matrix and the colored layer in the display area of the color filter is in the range of 0.1 to 0.4 μm.

  Also in the PSA type liquid crystal display panel, if the step is 0.4 μm, the alignment of the liquid crystal is not disturbed and the display quality is not impaired.

  Next, the invention according to claim 2 is the color filter according to claim 1, wherein the colored layer is composed of filter segments of three colors of red, green and blue.

  The invention according to claim 3 is the color filter according to claim 1 or 2, wherein the thickness of the colored layer is in the range of 1.0 μm to 3.0 μm.

  The invention according to claim 4 is the color filter according to any one of claims 1 to 3, wherein the film thickness of the black matrix is in the range of 0.8 μm to 1.5 μm.

Next, the invention described in claims 5 to 7 relates to a photosensitive composition of each color applied when the color filter described in claims 1 to 4 is manufactured, on a substrate provided with the black matrix. The photosensitive composition of each color can be coated, exposed and developed, and then heat-cured to form a colored layer of each color.

The invention according to claim 5 relates to a red photosensitive composition, comprising a resin, a compound having an unsaturated double bond, a photopolymerization initiator, a red colorant and a solvent,
The ratio of the resin and the compound having an unsaturated double bond (compound having an unsaturated double bond / resin) is in the range of 0.3 to 0.4,
And the ratio of the compound having an unsaturated double bond and the photopolymerization initiator (photopolymerization initiator / compound having an unsaturated double bond) is in the range of 0.15 or more.
It is a red photosensitive composition characterized by the above-mentioned.

The invention according to claim 6 relates to a green photosensitive composition, comprising a resin, a compound having an unsaturated double bond, a photopolymerization initiator, a green colorant and a solvent,
The ratio of the resin and the compound having an unsaturated double bond (compound / resin having an unsaturated double bond) is in the range of 0.4 to 0.6,
And the ratio of the compound having an unsaturated double bond and the photopolymerization initiator (photopolymerization initiator / compound having an unsaturated double bond) is in the range of 0.15 or more.
It is the green photosensitive composition characterized by the above-mentioned.

The invention according to claim 7 relates to a blue photosensitive composition, comprising a resin, a compound having an unsaturated double bond, a photopolymerization initiator, a blue colorant and a solvent,
The ratio of the resin and the compound having an unsaturated double bond (compound / resin having an unsaturated double bond) is in the range of 0.6 to 1.4,
And the ratio of the compound having an unsaturated double bond and the photopolymerization initiator (photopolymerization initiator / compound having an unsaturated double bond) is in the range of 0.33 or more.
It is a blue photosensitive composition characterized by the above-mentioned.

  Next, an invention according to an eighth aspect is a liquid crystal display panel using the color filter according to any one of the first to fourth aspects.

  According to the present invention, since the step formed by the overlap of the black matrix and the colored layer is 0.1 μm to 0.4 μm, a color filter having excellent flatness without providing a protective layer and without polishing. Obtainable. This color filter is suitable for the aforementioned PSA liquid crystal display panel.

Cross-sectional explanatory drawing showing the structure of the color filter Cross-sectional explanatory drawing showing a horn step when a color filter is formed

  FIG. 2 is a schematic cross-sectional explanatory diagram in which a portion where the end portion of the colored layer overlaps the black matrix is enlarged.

  As shown in FIG. 2, the colored layer is overlapped with the black matrix at the ends. The step formed by the overlap between the black matrix and the colored layer generated on the edge is 0.1 μm to 0.4 μm or less. When the horn step is larger than 0.4 μm, display defects such as liquid crystal alignment disorder occur.

  Next, the black matrix of the present invention will be described.

  The film thickness of the black matrix of the present invention is in the range of 0.8 μm to 1.5 μm. When the film thickness is less than 0.8 μm, a sufficient concentration for light shielding cannot be obtained, and when it is more than 3.0 μm, the coatability of the photosensitive composition is deteriorated when the colored layer is formed.

  Next, the colored layer of the present invention will be described.

  The colored layer of the present invention is composed of filter segments of three colors of red, green, and blue, and the thickness of the colored layer is in the range of 1.0 μm to 3.0 μm. When the colored layer is 1.0 μm or less, it is necessary to increase the pigment concentration in the solid content of the photosensitive composition, thereby increasing the viscosity of the photosensitive composition and forming a uniform pattern. It becomes difficult. When the thickness of the colored layer is 3.0 μm or more, it may be difficult to adjust the cell gap in the bonding process between the color filter substrate and the counter substrate in the manufacturing process of the liquid crystal display panel.

  Next, the photosensitive coloring composition of each color used for forming these three color filter segments will be described. Each photosensitive coloring composition is composed of a resin, a compound having an unsaturated double bond, a photopolymerization initiator, a coloring material for each color, a solvent, and a surfactant. The color of these photosensitive coloring compositions is determined by the color material to be blended.

Examples of the color material blended in the red coloring composition include C.I. I. Pigment Red
7, 14, 41, 48: 2, 48: 3, 48: 4, 81: 1, 81: 2, 81: 3, 81: 4, 146, 168, 177, 178, 179, 184, 185, 187, Red pigments such as 200, 202, 208, 210, 246, 254, 255, 264, 270, 272, and 279 can be used, and a yellow pigment can also be used in combination.

  Examples of yellow pigments include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 10, 12, 13, 14, 15, 16, 17, 18, 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, 93, 94, 95, 97, 98, 100, 101, 104, 106, 108, 109, 110, 113, 114, 115, 116, 117, 118, 119, 120, 123, 126, 127, 128, 129, 147, 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, 187 188, 193, 194, 199, 198, 213, 214 and the like.

  Examples of the color material blended in the green coloring composition include C.I. I. Green pigments such as Pigment Green 7, 10, 36, 37, and 58 can be used, and a yellow pigment can be used in combination. As this yellow pigment, the same pigments as those described in the description of the red coloring composition can be used.

  Examples of the color material blended in the blue coloring composition include C.I. I. Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 22, 60, 64, and the like can be used, and a purple pigment can be used in combination. Examples of purple pigments used in combination include C.I. I. Pigment Violet 1, 19, 23, 27, 29, 30, 32, 37, 40, 42, 50 and the like.

In combination with the organic pigment, an inorganic pigment may be used in combination in order to ensure good coatability, sensitivity, developability and the like while balancing saturation and lightness. Examples of the inorganic pigment include metal oxide powders such as ultramarine blue, bitumen, chromium oxide green, and cobalt green, metal sulfide powder, and metal powder. Furthermore, for color matching, a dye can be contained within a range that does not lower the heat resistance.

  Examples of compounds having an unsaturated double bond (photopolymerizable monomer) include tricyclodecane dimethylol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and pentaerythritol tri (meth). Acrylate, ethylene oxide modified trimethylolpropane tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate , Ethylene oxide modified trimethylolpropane tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate Various acrylic acid esters and methacrylic acid esters, such as rate and the like Representative examples.

As photopolymerization initiators, acetophenone compounds, benzoin compounds, benzophenone compounds, thioxanthone compounds, triazine compounds, oxime ester compounds, phosphine compounds, quinone compounds, borate compounds, carbazole compounds, imidazole compounds Examples of the acetophenone compound include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methyl Examples include propan-1-one, 1-hydroxycyclohexyl phenyl ketone, and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one.

  Examples of benzoin compounds include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzyl dimethyl ketal.

  Examples of the benzophenone compounds include benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, and the like.

  Examples of the thioxanthone compound include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2.4-diisopropylthioxanthone.

  Examples of triazine compounds include 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, and 2- (p-methoxyphenyl) -4,6-bis. (Trichloromethyl) -s-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2-pienyl-4,6-bis (trichloromethyl) -s-triazine, 2 , 4-Bis (trichloromethyl) -6-styryl-s-triazine, 2- (naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-methoxy-naphtho-) 1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, 2,4-trichloromethyl (4′- Tokishisuchiriru) -6-triazine and the like.

  Examples of oxime ester compounds include 1,2-octanedione, 1- [4- (phenylthio) -2- (o-benzoyloxime)], o- (acetyl) -N- (1-phenyl-2-oxo- Examples include 2- (4′-methoxy-naphthyl) ethylidene) hydroxylamine and the like.

  Examples of the phosphine compound include bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide.

  Examples of the quinone compound include 9,10-phenanthrenequinone, camphorquinone, and ethylanthraquino.

  As sensitizers, α-acyloxy esters, acylphosphine oxides, methylphenylglyoxylate, benzyl, 9,10-phenanthrenequinone, camphorquinone, ethylanthraquinone, 4,4′-diethylisophthalophenone 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, 4,4′-diethylaminobenzophenone, and the like can also be used in combination.

  As the resin, a transparent resin having a transmittance of 80% or more in the entire wavelength region of 400 to 700 nm in the visible light region can be used. More preferably, the transparent resin is 95% or more. The transparent resin includes a thermoplastic resin, a thermosetting resin, and a photosensitive resin, and these can be used alone or in combination 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 resins, polyamide resins, rubber resins, cyclized rubber resins, celluloses, polyethylene, polypropylene, 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.

  As the photosensitive resin, a (meth) acrylic compound having a reactive substituent such as an isocyanate group, an aldehyde group or 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 cinnamic acid and introducing a photocrosslinkable group such as a (meth) acryloyl group or a styryl group into the linear polymer is used. In addition, 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.

  Examples of the solvent include cyclohexanone, ethyl cellosolve acetate, butyl cellosolve acetate, 1-methoxy-2-propyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, ethylbenzene, ethylene glycol diethyl ether, xylene, ethyl cellosolve, methyl-n-amyl ketone, Examples include propylene glycol monomethyl ether toluene, methyl ethyl ketone, ethyl acetate, methanol, ethanol, isopropyl alcohol, butanol, isobutyl ketone, petroleum solvents, and the like, which are used alone or in combination.

  A surfactant or the like may be added to the colored photosensitive composition of the present invention. As the surfactant, surfactants such as fluorine surfactants, anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, and silicone surfactants can be used. Examples of the fluorosurfactant include perfluoroalkyl phosphate esters and perfluoroalkyl carboxylates. Examples of anionic surfactants include higher fatty acid alkali salts, alkyl sulfonates, and alkyl sulfates. Examples of the cationic surfactant include higher amine halogenates and quaternary ammonium salts. Examples of the nonionic surfactant include polyethylene glycol alkyl ether, polyethylene glycol fatty acid ester, sorbitan fatty acid ester, fatty acid monoglyceride and the like.

  Also, if necessary, conventional additives such as thermal polymerization inhibitors such as anisole, hydroquinone, pyrocatechol, tert-butylcatechol, phenothiazine, plasticizers, adhesion promoters, fillers, antifoaming agents, leveling agents, etc. Can be added.

  In the present invention, the numerical range of the ratio of the resin and the compound having an unsaturated double bond (compound having an unsaturated double bond / resin = M / P) needs to be different for each color. Further, the ratio of the compound having an unsaturated double bond and the photopolymerization initiator (photopolymerization initiator / compound having an unsaturated double bond = I / M) also varies depending on each color.

  In a red photosensitive composition, M / P needs to exist in the range of 0.3 or more and 0.4 or less, and I / M needs to exist in the range of 0.15 or more. As can be understood from the examples and comparative examples described later, outside this range, the cross-sectional shape and sensitivity of the pattern deteriorate, the flatness deteriorates due to the thin film thickness of the pixel near the black matrix, and the horn step is 0.4 μm. Become bigger.

  In a green photosensitive composition, M / P needs to exist in the range of 0.4 or more and 0.6 or less, and I / M needs to exist in the range of 0.15 or more. As can be understood from the examples and comparative examples described later, outside this range, the cross-sectional shape and sensitivity of the pattern deteriorate, the flatness deteriorates due to the thin film thickness of the pixel near the black matrix, and the horn step is 0.4 μm. Become bigger.

  In the blue photosensitive composition, it is preferable that M / P is in the range of 0.6 or more and 1.4 or less and I / M is in the range of 0.33 or more. As can be understood from the examples and comparative examples described later, outside this range, the cross-sectional shape and sensitivity of the pattern deteriorate, the flatness deteriorates due to the thin film thickness of the pixel near the black matrix, and the horn step is 0.4 μm. Become bigger.

  The color filter of the present invention can be produced by forming a colored layer of each color on a transparent substrate using the colored composition of the present invention by a printing method or a photolithography method. For example, a colored layer can be formed by coating a photosensitive composition of each color on a substrate provided with a black matrix, exposing and developing, and then heat-curing. This colored layer forming step can be repeated for three colors of red, green, and blue to produce a color filter.

  The transparent substrate may be transparent and have a certain degree of rigidity, and films or thin plates such as glass, polyester, polycarbonate, polymethyl methacrylate, polyethylene terephthalate, and acrylic resin can be used.

  In the development, an aqueous solution such as sodium carbonate or sodium hydroxide can be used as an alkaline developer. Moreover, organic alkalis, such as a dimethyl benzylamine and a triethanolamine, can also be used. Moreover, an antifoamer and surfactant can also be added to a developing solution. In order to increase the UV exposure sensitivity, after coating and drying the colored resist material, a water-soluble or alkali-soluble resin such as polyvinyl alcohol or a water-soluble acrylic resin is applied and dried to form a film that prevents polymerization inhibition by oxygen. Thereafter, ultraviolet exposure can also be performed.

  Hereinafter, the present invention will be described based on examples, but the present invention is not limited thereto. In the examples and comparative examples, “parts” means “parts by weight”.

[Adjustment of binder resin]
(Binder resin synthesis example)
70 parts of cyclohexanone is placed in a reaction vessel, heated to 80 ° C. while injecting nitrogen gas into the vessel, and at the same temperature, 25 parts of benzyl methacrylate, 15 parts of 2-hydroxyethyl methacrylate, 20 parts of methacrylic acid, paracumylphenol ethylene oxide A mixture of 30 parts of modified acrylate (“Aronix M110” manufactured by Toagosei Co., Ltd.) and 10 parts of methyl methacrylate was added dropwise over 2 hours to carry out a polymerization reaction. After completion of the dropwise addition, the mixture was further reacted at 80 ° C. for 3 hours, then 0.2 parts of azobisisobutyronitrile dissolved in 10 parts of cyclohexanone was added, and the reaction was further continued at 80 ° C. for 1 hour. A photosensitive transparent resin copolymer solution was obtained. After cooling to room temperature, about 2 g of the non-photosensitive transparent resin solution was sampled and heated and dried at 180 ° C. for 20 minutes to measure the non-volatile content. The non-photosensitive transparent resin solution synthesized earlier had a non-volatile content of 20% by weight. Cyclohexanone was added so that a non-photosensitive resin solution was prepared. The weight average molecular weight Mw of the obtained transparent resin 1 was 9300.

  Also, 70 parts of cyclohexanone was placed in a reaction vessel, heated to 80 ° C. while injecting nitrogen gas into the vessel, and 25 parts of benzyl methacrylate, 14 parts of 2-hydroxyethyl methacrylate, 13 parts of methacrylic acid, paracumylphenol at the same temperature. A mixture of 25 parts of ethylene oxide-modified acrylate (“Aronix M110” manufactured by Toa Gosei Co., Ltd.) and 23 parts of isobutyl methacrylate was added dropwise over 2 hours to carry out a polymerization reaction. After completion of the dropwise addition, the mixture was further reacted at 80 ° C. for 3 hours, then 0.2 parts of azobisisobutyronitrile dissolved in 10 parts of cyclohexanone was added, and the reaction was further continued at 80 ° C. for 1 hour. A photosensitive transparent resin copolymer solution was obtained. After cooling to room temperature, about 2 g of the non-photosensitive transparent resin solution was sampled and heated and dried at 180 ° C. for 20 minutes to measure the non-volatile content. The non-photosensitive transparent resin solution synthesized earlier had a non-volatile content of 20% by weight. Cyclohexanone was added so that a non-photosensitive resin solution was prepared. The obtained transparent resin 2 had a weight average molecular weight Mw of 33,000.

[Preparation of photosensitive composition]
After stirring and mixing the mixture of the composition of the following Table 1-Table 6 uniformly, it filtered with a 0.5 micrometer filter, and obtained the blue photosensitive compositions 1-10.

  In addition, “Aronix M402 (dipentaerythritol penta and hexaacrylate)” manufactured by Toagosei Co., Ltd. was used as a photopolymerizable monomer.

  Moreover, “Irg379” and “OXE-02” manufactured by Ciba Specialty Chemicals were used as photopolymerization initiators.

カラーフィルタ作製用感光性組成物として、赤色感光性組成物１〜４を実施例１〜４、赤色感光性組成物５〜１０を比較例１〜６とした。また、緑色感光性組成物１〜４を実施例５〜８、緑色感光性組成物５〜１０を比較例７〜１２とした。また、青色感光性組成物１〜４を実施例９〜１２、青色感光性組成物５〜１０を比較例１３〜１８とした。

As photosensitive compositions for producing color filters, red photosensitive compositions 1 to 4 were designated as Examples 1 to 4, and red photosensitive compositions 5 to 10 were designated as Comparative Examples 1 to 6. Moreover, the green photosensitive compositions 1-4 were made into Examples 5-8, and the green photosensitive compositions 5-10 were made into Comparative Examples 7-12. Moreover, the blue photosensitive compositions 1-4 were made into Examples 9-12, and the blue photosensitive compositions 5-10 were made into Comparative Examples 13-18.

[Evaluation item]
(Sensitivity evaluation)
About each blue photosensitive composition prepared by said each Example and comparative example, the sensitivity was evaluated as follows.

First, the film thickness after post-baking the red photosensitive compositions 1 to 10, the green photosensitive compositions 1 to 10, and the blue photosensitive compositions 1 to 10 obtained in the above examples and comparative examples on a glass substrate. Was applied by spin coating so as to be 2.4 μm, and then dried to form a blue photosensitive layer. Next, after prebaking at 70 ° C. for 20 minutes, UV exposure was performed through a photomask having a 50 μm fine line pattern by a proximity exposure method using a proximity aligner. The exposure amount was set to 11 levels of 10, 20, 30, 50, 80, 100, 150, ²⁰⁰ , 300, 400, and 500 mJ / cm ² .

Next, shower development was performed using a 1.25% by mass sodium carbonate solution, followed by washing with water to complete patterning. The film thickness of the obtained filter segment was divided by the film thickness of the unexposed / undeveloped portion to calculate the remaining film ratio. Then, the exposure sensitivity curve was plotted with the horizontal axis representing the common logarithm of the exposure dose and the vertical axis representing the remaining film ratio after development. From the obtained exposure sensitivity curve, the minimum exposure amount at which the post-development residual film ratio reaches 85% or more is defined as the saturation exposure amount, that is, the sensitivity of the blue photosensitive composition, and less than 300 mJ / cm ² is represented by ◯, and 300 mJ / was × determines cm ² or more.

(Pattern shape)
The film thickness after post-baking the red photosensitive compositions 1 to 10, the green photosensitive compositions 1 to 10, and the blue photosensitive compositions 1 to 10 obtained in the above examples and comparative examples on a glass substrate is 2. A blue photosensitive layer was formed by coating by spin coating to a thickness of 4 μm and then drying. Then, after pre-baking at 70 ° C. for 20 minutes, exposure was performed with a saturated exposure amount of each blue photosensitive composition by a proximity exposure method using a proximity aligner. Next, after developing by shower using a 1.25 mass% sodium carbonate solution, washing with water and completing patterning. The substrate for evaluation was obtained by baking at 230 ° C. for 20 minutes in a clean oven.

  The shape of the obtained pattern was observed with an SEM.

(Tsuno step evaluation)
A red photosensitive composition 1-10, a green photosensitive composition 1-10, and a blue photosensitive sensitivity obtained in the above examples and comparative examples on a glass substrate provided with a stripe-shaped black matrix having a thickness of 1.1 μm. Compositions 1 to 10 were applied by spin coating so that the film thickness after post-baking was 2.4 μm and then dried to form a blue photosensitive layer. Then, after pre-baking at 70 ° C. for 20 minutes, exposure was performed with a saturated exposure amount of each blue photosensitive composition by a proximity exposure method using a proximity aligner. Next, after developing by shower using a 1.25 mass% sodium carbonate solution, washing with water and completing patterning. The substrate for evaluation was obtained by baking at 230 ° C. for 20 minutes in a clean oven.

  The obtained pattern shape was observed with an SEM, and the height of the horn step was 0.1 μm or more and 0.4 μm or less.

(Evaluation results)
The results of Examples 1 to 12 and Comparative Examples 1 to 18 are shown in Tables 7 to 12.

（考察）
（１）まず赤色感光性組成物について考察する。

(Discussion)
(1) First, the red photosensitive composition will be considered.

(A) In Comparative Example 1 where the ratio of the resin and the compound having an unsaturated double bond (M / P) is 0.20, the saturation exposure amount exceeds 300 mJ / cm ² , and the sensitivity is low, Unbearable for practical use. In Comparative Example 2 where M / P is 0.20, the sensitivity is good, but the horn step exceeds 0.4 μm. On the other hand, in Examples 1 and 2 where M / P is 0.30, the sensitivity is good and the horn step is small. From this, it is understood that M / P needs to be 0.3 or more in order to have a sensitivity that can withstand practical use and to reduce the horn step.

  (B) In Comparative Examples 3 and 4 where M / P is 0.50, the horn step exceeds 0.4 μm. On the other hand, in Examples 3 and 4 where M / P is 0.40, the sensitivity is also good and the horn step is small. From this, it can be seen that M / P needs to be 0.4 or less in order to have sensitivity that can withstand practical use and to reduce the horn step.

(C) Comparative Examples 5 and 6 in which the ratio (I / M) of the compound having an unsaturated double bond to the photopolymerization initiator is 0.10 even when M / P is between 0.30 and 0.40 Then, the saturation exposure amount exceeds 300 mJ / cm ² , the sensitivity thereof is low, and it cannot be put into practical use. On the other hand, in Examples 1 to 3 where the I / M is 0.15, the sensitivity is good and the step difference is small. Therefore, in order to have a sensitivity that can withstand practical use and to reduce the horn step, M / P is between 0.30 and 0.40, and I / M is 0.15 or more. I understand that it is necessary.

  (2) Next, the green photosensitive composition will be considered.

(A) In Comparative Examples 7 and 8 where M / P is 0.20, the saturation exposure amount exceeds 300 mJ / cm ² , the sensitivity thereof is low, and it cannot be put into practical use. On the other hand, in Examples 5 and 6 where M / P is 0.40, the sensitivity is good and the horn step is small. From this, it is understood that M / P needs to be 0.3 or more in order to have a sensitivity that can withstand practical use and to reduce the horn step.

  (B) In Comparative Examples 9 and 10 where M / P is 0.80, the horn step exceeds 0.4 μm. On the other hand, in Examples 7 and 8 where M / P is 0.60, the sensitivity is good and the horn step is small. From this, it can be seen that M / P needs to be 0.4 or less in order to have sensitivity that can withstand practical use and to reduce the horn step.

(C) In Comparative Examples 11 and 12 where I / M is 0.10 even when M / P is between 0.40 and 0.60, the saturation exposure amount exceeds 300 mJ / cm ² , and the sensitivity Is low and unbearable for practical use. On the other hand, in Examples 5 and 7 in which the I / M is 0.15, the sensitivity is good and the horn step is small. Therefore, in order to have a sensitivity that can withstand practical use and to reduce the horn step, M / P is between 0.30 and 0.40, and I / M is 0.15 or more. I understand that it is necessary.

  (3) Next, the blue photosensitive composition will be considered.

  (A) In Comparative Examples 13 and 14 where M / P is 0.40, the horn step exceeds 0.4 μm. On the other hand, in Examples 9 and 10 in which M / P is 0.60, the sensitivity is also good and the horn step is small. From this, it is understood that M / P needs to be 0.3 or more in order to have a sensitivity that can withstand practical use and to reduce the horn step.

  (B) On the other hand, in Comparative Examples 15 and 16 in which M / P is 1.60, the horn step exceeds 0.4 μm. On the other hand, in Examples 11 and 12 where M / P is 1.40, the sensitivity is also good and the horn step is small. Therefore, if the M / P is too small or too large, the horn step becomes large, and in order to set the horn step to 0.4 μm and to have sensitivity to withstand practical use, the M / P is 0.60. It can be seen that it should be ˜1.40.

(C) Even if M / P is between 0.60 and 1.40, in Comparative Example 17 where I / M is 0.15, the saturation exposure amount exceeds 300 mJ / cm ² , and the sensitivity is low. Unbearable for practical use. Further, in Comparative Example 18 in which I / M is 0.15, the sensitivity is good, but the pattern shape is an overhang shape, which is not practical. On the other hand, in Examples 9 and 11 where the I / M is 0.33, the sensitivity is good, the step difference is small, and the cross-sectional shape of the pattern is a forward tapered shape. From this, in order to have a sensitivity that can withstand practical use, to reduce the horn step, and to form a forward taper, M / P is between 0.60 and 1.40, and I / M is It turns out that it needs to be 0.33 or more.

DESCRIPTION OF SYMBOLS 1 Color filter 2 Transparent substrate 3 Black matrix 4 Colored layer 4a Red colored layer 4b Green colored layer 4c Blue colored layer 5 Overcoat layer 6 Tsuno step

Claims (8)

A liquid crystal display panel in which a liquid crystal and a polymerizable composition are sealed between two substrates, and the alignment is fixed by irradiating the liquid crystal display panel containing the liquid crystal and the polymerizable composition with light. In the color filter used for the panel,
A color filter characterized in that a step formed by an overlap between a black matrix and a colored layer in a display area of the color filter is in a range of 0.1 to 0.4 μm.   The color filter according to claim 1, wherein the colored layer includes filter segments of three colors of red, green, and blue.   The color filter according to claim 1 or 2, wherein the color layer has a thickness in a range of 1.0 µm to 3.0 µm.   The color filter according to claim 1, wherein the black matrix has a thickness in a range of 0.8 μm to 1.5 μm. Consists of a resin, a compound having an unsaturated double bond, a photopolymerization initiator, a red colorant and a solvent,
The ratio of the resin and the compound having an unsaturated double bond (compound having an unsaturated double bond / resin) is in the range of 0.3 to 0.4,
And the ratio of the compound having an unsaturated double bond and the photopolymerization initiator (photopolymerization initiator / compound having an unsaturated double bond) is in the range of 0.15 or more.
The red photosensitive composition characterized by the above-mentioned. Consists of a resin, a compound having an unsaturated double bond, a photopolymerization initiator, a green colorant and a solvent,
The ratio of the resin and the compound having an unsaturated double bond (compound / resin having an unsaturated double bond) is in the range of 0.4 to 0.6,
And the ratio of the compound having an unsaturated double bond and the photopolymerization initiator (photopolymerization initiator / compound having an unsaturated double bond) is in the range of 0.15 or more.
The green photosensitive composition characterized by the above-mentioned. Consists of a resin, a compound having an unsaturated double bond, a photopolymerization initiator, a blue colorant and a solvent,
The ratio of the resin and the compound having an unsaturated double bond (compound / resin having an unsaturated double bond) is in the range of 0.6 to 1.4,
And the ratio of the compound having an unsaturated double bond and the photopolymerization initiator (photopolymerization initiator / compound having an unsaturated double bond) is in the range of 0.33 or more.
A blue photosensitive composition characterized by the above.   A liquid crystal display panel using the color filter according to claim 1.

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