JP2013097235A - Photosensitive coloring composition and color filter substrate using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive coloring composition applied to a color filter substrate having a laminated photospacer, which allows controlling the laminate height to a desired height without causing deterioration of peeling development and storage stability, even in a photosensitive coloring composition containing an extender pigment for controlling the height of the laminated photospacer; and a color filter substrate using it.SOLUTION: In a photosensitive coloring composition used for a color filter substrate having a laminated photospacer formed by lamination of photosensitive coloring compositions with one or more colors, comprising a black matrix on a substrate, colored pixels having a plurality of colors, and the colored pixels on the black matrix, 1 to 10 mass% of a transparent extender pigment is contained in the total solid of the photosensitive coloring composition and the molecular weight of the photopolymerizable monomer is in the range of 1000 to 1500.

Description

  The present invention relates to a photosensitive coloring composition for a color filter used for producing a color filter used in a color liquid crystal display device and the like, and a color filter formed using the same.

  Liquid crystal display devices are widely used in various display devices because they are small, thin, lightweight, and have low power consumption. In such a liquid crystal display device, a spacer for maintaining a predetermined thickness (cell gap) of the liquid crystal layer is disposed between the color filter substrate and the thin film transistor (TFT) substrate.

  If this cell gap is not accurately maintained, the thickness of the liquid crystal layer will be different and coloring due to the difference in the optical rotation characteristics of the liquid crystal or partial color unevenness will be adversely affected. For example, a method of forming a columnar resin spacer at a desired position, for example, on a black matrix in a lattice pattern at the boundary between pixels, has become a mainstream by photolithography [Patent Documents 1 to 3]. 4]. Such a spacer is hereinafter referred to as a photo spacer.

  In recent years, a method has also been proposed in which a photo spacer is formed by three-dimensionally laminating a plurality of colored layers two-dimensionally [Patent Documents 5 to 7]. Since it is not necessary to add a process for arranging the photo spacer, the color filter can be manufactured at low cost. However, the formation of spacers (laminated photo spacers) by laminating colored layers is a repelling phenomenon caused by poor wettability to the colored composition hard film formed up to the previous step, and flow in the firing step. When priority is given to the thickness of the colored pixels in order to obtain a desired hue, it is difficult to control the height to a desired height. In addition, since the thickness of the colored composition formed on the black matrix portion is likely to be thinner than the pixel thickness, the colored layer thickness should be increased when it is desired to increase the height of the laminated photo spacer to be formed. Therefore, it is necessary to increase the thickness of the black matrix, and to increase the load on the process and to reduce the degree of freedom in design.

  As a method for controlling the height of the laminated photo spacer as described above, a method by adding a colorless and transparent transparent extender pigment has been proposed [Patent Documents 8 and 9]. However, in the photosensitive coloring composition containing the above-mentioned transparent extender pigment, there are problems such as development stains due to peeling development in the development process at the time of pattern formation, and poor storage stability. Moreover, even if the film thickness of the laminated photospacer could be controlled, it could not be said that it was suitable for production.

JP 9-258192 A Japanese Patent Laid-Open No. 11-248921 JP 2001-201750 A Japanese Patent Laid-Open No. 2001-108813 JP-A-4-93924 JP-A-4-184423 JP 2007-212826 A JP 2011-137913 A JP 2011-158537 A

  The present invention has been made in view of the above-described problems, and even in a photosensitive coloring composition containing a transparent extender pigment for controlling the height of a laminated photospacer, deterioration of peeling development and storage stability is deteriorated. It is an object of the present invention to provide a photosensitive coloring composition capable of controlling the stacking height to a desired height without causing such problems, and a color filter substrate formed using the same.

  As a result of investigations to solve the above-mentioned problems, the present inventors have found that the photosensitive coloring composition contains a variation in the laminated film thickness, peeling development, and deterioration in storage stability in the photosensitive coloring composition containing the transparent extender pigment. Clarified that it is caused by the amount of transparent extender pigment in the product and the type of photopolymerizable monomer, and found the condition that the stacking height can be controlled to the desired height without any problem of elimination of release development and storage stability. .

  That is, in the invention according to claim 1 of the present invention, a plurality of colored pixels made of a black matrix and a photosensitive coloring composition are laminated on a transparent substrate, and one or more colors of the photosensitive coloring composition are laminated on the black matrix. A photosensitive coloring composition for a color filter substrate comprising a laminated photo spacer formed in the above-described manner, wherein the photosensitive coloring composition is at least a colorant, a transparent extender pigment, a transparent resin, a photopolymerizable monomer, light It contains a polymerization initiator, contains 1 to 10% by mass of a transparent extender pigment in the total solid content of the photosensitive coloring composition, and the molecular weight of the photopolymerizable monomer is in the range of 1000 to 1500. It is the photosensitive coloring composition characterized.

  Next, in the invention according to claim 2 of the present invention, the transparent extender pigment is at least one selected from the group consisting of silicon oxide, barium sulfate, titanium oxide, zinc oxide, aluminum oxide, magnesium oxide, calcium carbonate, and magnesium carbonate. It is a photosensitive coloring composition of Claim 1 characterized by the above-mentioned.

  According to a third aspect of the present invention, there is provided a color filter substrate comprising a colored pixel and a laminated photospacer formed using the photosensitive coloring composition according to the first or second aspect. It is.

  According to the photosensitive coloring composition of the present invention, the photosensitive coloring composition forming the pixel and the laminated photospacer contains 1 to 10% of a transparent extender pigment in its solid content, and is photopolymerizable. A photosensitive coloring composition having excellent storage stability without peeling development, while obtaining an effect of increasing the laminated film thickness due to the inclusion of the transparent extender pigment, because the monomer has a molecular weight in the range of 1000 to 1500. Therefore, it is possible to form a laminated photospacer having a high rise rate compared to the pixel film thickness without causing deterioration in process yield. That is, in the color filter substrate formed using the photosensitive coloring composition of the present invention, the colored pixels can be formed with a thinner film, so that the burden on the process and the amount of the coloring composition used can be reduced. It becomes possible.

1 is a schematic cross-sectional view illustrating an embodiment of a color filter substrate according to the present invention. It is a cross-sectional schematic diagram which shows one Embodiment of the lamination | stacking photospacer mounted on the black matrix which concerns on this invention.

  The photosensitive coloring composition of the present invention and a color filter substrate using the same will be described in detail below based on one embodiment.

  The photosensitive coloring composition according to the present invention is a photosensitive coloring composition containing at least a colorant, a transparent extender pigment, a transparent resin, a photopolymerizable monomer, and a photopolymerization initiator, 1 to 10% by mass of a transparent extender pigment is contained in the total solid content, and the molecular weight of the photopolymerizable monomer is in the range of 1000 to 1500.

  The transparent extender pigment contained in the photosensitive coloring composition of the present invention uses at least one selected from the group consisting of silicon oxide, barium sulfate, titanium oxide, zinc oxide, aluminum oxide, magnesium oxide, calcium carbonate, and magnesium carbonate. Can do. Moreover, it is preferable that the average particle diameter of a transparent extender pigment is 500 nm or less from a transparency point. In particular, fine powder silica gel having a refractive index close to that of a binder resin, excellent dispersibility in the resin, and exhibiting thickening can be more preferably used.

  In the photosensitive coloring composition which concerns on this invention, 1-10 mass% with respect to the total solid of a photosensitive coloring composition, Preferably it contains 2-5 mass% transparent extender pigment. If the amount of the transparent extender pigment contained in the total solid content of the photosensitive coloring composition is less than 1% by mass, the thickening effect is not exhibited, and the increase in the laminated film thickness by controlling the fluidity is not achieved. If it exceeds 10% by mass, the developing effect and the storage stability are deteriorated due to the thickening effect. Moreover, if it is in the said range, the influence on the contrast when it is set as a color filter will also be satisfactory.

  Furthermore, in the photosensitive coloring composition which concerns on this invention, the molecular weight of a photopolymerizable monomer exists in the range of 1000-1500, It is characterized by the above-mentioned. This occurs because the peeling development in the photosensitive coloring composition containing the transparent extender pigment is uneven in the portion where the monomer and the like are easily dissolved and the portion where the transparent extender pigment and the like are difficult to be dissolved. However, when the molecular weight is 1000 or less, the difference from the developability of the monomer is large, resulting in peeling development, fluidity during the coating process and baking process is large, and the laminated film thickness tends to be thin. If the molecular weight is 1500 or more, there will be no difference in developability, but the tact over and thickening effects due to the decrease in developability as a photosensitive coloring composition will be too great, and the storage stability will also be reduced. . When the molecular weight is in the range of 1000 to 1500, there is no peeling development due to non-uniformity of developability, and the laminated film thickness can be increased by the effect of fluidity control.

  In the present invention, a polyfunctional urethane acrylate having a (meth) acryloyl group obtained by reacting a polyfunctional isocyanate with a (meth) acrylate having a hydroxyl group can be suitably used as the photopolymerizable monomer as described above. If it is in the said molecular weight range, the combination of the (meth) acrylate and polyfunctional isocyanate which has a hydroxyl group is arbitrary, and it does not specifically limit. Moreover, one type of polyfunctional urethane acrylate may be used alone, or two or more types may be used in combination.

  Here, as the (meth) acrylate having a hydroxyl group, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol tri (meth) acrylate, ditrimethylol Propane tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol ethylene oxide modified penta (meth) acrylate, dipentaerythritol propylene oxide modified penta (meth) acrylate, dipentaerythritol caprocalactone modified penta (meth) ) Acrylate, glycerol acrylate methacrylate, glycerol dimethacrylate, 2-hydroxy-3-acryloylpropyl methacrylate , Epoxy group-containing compound and the carboxy (meth) reaction product of acrylate, hydroxyl group-containing polyol polyacrylate, and the like. Examples of the polyfunctional isocyanate include tolylene diisocyanate, hexamethylene diisocyanate, diphenylmethylene diisocyanate, isophorone diisocyanate, and polyisocyanate.

  As the colorant contained in the photosensitive coloring composition according to the present invention, commercially available organic pigments can be used. Moreover, you may use together a dye, a natural pigment | dye, and an inorganic pigment. As the organic pigment, those having high color developability and heat resistance, particularly high heat decomposition resistance are preferably used. An organic pigment can be used individually by 1 type or in mixture of 2 or more types. Further, the organic pigment may be refined by salt milling, acid pasting or the like.

  Below, the specific example of the organic pigment which can be used for the photosensitive coloring composition which concerns on this invention is shown by a color index (CI) number. For the red pixel, for example, 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, Red pigments such as 187, 200, 202, 208, 210, 246, 254, 255, 264, 270, 272, and 279 can be used, and a yellow pigment and an orange 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, 138, 139, 147, 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, 187, 188, 193, 194, 199, 198, 213, 214 and the like. Examples of the orange pigment include C.I. I. Pigment Orange 36, 43, 51, 55, 59, 61, 71, 73 and the like.

  For example, 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 the yellow pigment, the same pigments as those used for the red pixel can be used.

  Examples of blue pixels 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 include C.I. I. Pigment Violet 1, 19, 23, 27, 29, 30, 32, 37, 40, 42, 50 and the like. In the above, as the blue pigment, C.I. I. Pigment Blue 15: 6, and violet pigments include C.I. I. Pigment Violet 23 is preferable in terms of excellent light resistance, heat resistance, transparency, coloring power, and the like.

  The transparent resin that can be used in the photosensitive resin composition of the present invention is a transparent 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, Non-photosensitive resins such as thermoplastic resins and thermosetting resins, and photosensitive resins are included. Furthermore, if necessary, a monomer or an oligomer that is a precursor thereof and is cured by irradiation with radiation to form a transparent resin can be used alone or in combination of two or more.

  The non-photosensitive resin is a resin having no ethylenically unsaturated double bond, and examples of the thermoplastic resin include butyral resin, styrene-maleic acid copolymer, chlorinated polyethylene, chlorinated polypropylene, and polychlorinated resin. Vinyl, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyurethane resin, polyester resin, acrylic resin, alkyd resin, styrene resin, polyamide resin, rubber resin, cyclized rubber resin, celluloses, polybutadiene, A polyimide resin etc. are mentioned. Examples of the thermosetting resin include an epoxy resin, a benzoguanamine resin, a rosin-modified maleic acid resin, a rosin-modified fumaric acid resin, a phenol resin, a melamine resin, and a urea resin. However, these resins do not exhibit alkali solubility.

  At present, as the developer, an alkaline developer having a small influence on the environment is often used. For this reason, it is desirable to use an alkali-soluble resin as the resin binder. The alkali-soluble type non-photosensitive transparent resin is a transparent resin having a property of being dissolved in an alkaline aqueous solution and having no ethylenically unsaturated double bond. As such an alkali-soluble type non-photosensitive resin, Specifically, an acrylic resin having an acidic functional group, an α-olefin- (anhydrous) maleic acid copolymer, a styrene- (anhydrous) maleic acid copolymer, a styrene-styrene sulfonic acid copolymer, ethylene (meth) An acrylic acid copolymer, an isobutylene- (anhydrous) maleic acid copolymer, etc. are mentioned. Among them, at least one kind selected from an acrylic resin having an acidic functional group, an α-olefin- (anhydrous) maleic acid copolymer, a styrene- (anhydride) maleic acid copolymer, and a styrene-styrene sulfonic acid copolymer. Resins are preferably used.

  In addition, as the photosensitive resin, a linear polymer having a reactive functional group is reacted with a (meth) acrylic compound having a substituent capable of reacting with the reactive functional group, cinnamic acid, or the like, so that the ethylene resin does not react. Examples thereof include a resin in which a saturated double bond is introduced into the linear polymer. In addition, a linear polymer having a substituent capable of reacting with the reactive functional group is reacted with a (meth) acrylic compound having a reactive functional group, cinnamic acid, or the like, to thereby form an ethylenically unsaturated double bond. Resin introduced into the polymer. Examples of the reactive functional group include a hydroxyl group, a carboxyl group, and an amino group, and examples of the substituent capable of reacting with the reactive functional group include an isocyanate group, an aldehyde group, and an epoxy group.

  In addition, a linear polymer containing an acid anhydride such as a styrene-maleic anhydride copolymer or an α-olefin-maleic anhydride copolymer is a (meth) acrylic compound having a hydroxyl group such as hydroxyalkyl (meth) acrylate. Those half-esterified with can be used as the photosensitive resin.

  Examples of the photopolymerization initiator include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- Hydroxycyclohexyl phenyl ketone, 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane- Acetophenone photopolymerization initiators such as 1-one, benzoin photopolymerization initiators such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzyldimethyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4 − Benzophenone photopolymerization initiators such as phenyl benzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone Thioxanthone photopolymerization initiators such as 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 (trichloro (Romethyl) -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, etc. A polymerization initiator, a borate photopolymerization initiator, a carbazole photopolymerization initiator, an imidazole photopolymerization initiator, or the like is used. The amount of the photopolymerization initiator used is desirably 5 to 50% by mass of the photopolymerizable monomer, more preferably 10 to 30% by mass.

  The above photopolymerization initiators are used alone or in combination of two or more. As sensitizers, α-acyloxy ester, acylphosphine oxide, methylphenylglyoxylate, benzyl, 9,10-phenanthrenequinone. , Camphorquinone, ethyl anthraquinone, 4,4′-diethylisophthalophenone, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, 4,4′-diethylaminobenzophenone, etc. It can also be used together. The sensitizer can be contained in an amount of 0.1 to 60 parts by weight with respect to 100 parts by weight of the photopolymerization initiator.

  In addition, the photosensitive coloring composition according to the present invention is blended with a solvent such as an organic solvent in order to enable uniform coating on the substrate. It also has a function of uniformly dispersing the pigment. Suitable organic solvents to be used include, for example, 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. Examples thereof include monomethyl ether toluene, methyl ethyl ketone, ethyl acetate, methanol, ethanol, isopropyl alcohol, butanol, isobutyl ketone, petroleum solvent, etc., and these are used alone or in combination.

  When dispersing the pigment in the resin, a dispersant such as a surfactant, a resin-type pigment dispersant, and a dye derivative can be appropriately used. Further, additives such as a chain transfer agent, a surfactant, and a silane coupling agent may be added for the purpose of improving applicability, improving sensitivity, and improving adhesion.

  The photosensitive coloring composition of the present invention is produced by mixing each component and finely dispersing it using various dispersing means such as a shaker, a desper, a three-roll mill, a two-roll mill, a sand mill, a kneader, and an attritor. I can do it. The photosensitive coloring composition of the present invention is a coarse particle having a size of 5 μm or more, preferably a coarse particle having a size of 1 μm or more, more preferably a coarse particle having a size of 0.5 μm or more. It is preferable to remove the mixed dust.

  As shown in FIG. 1, the color filter substrate of the present invention is a photosensitive coloring composition comprising a black matrix (2), a plurality of colored pixels (3) on a transparent substrate (1), and a colored pixel on the black matrix. It has a laminated photospacer (4) formed by laminating one or more objects. In a general color filter substrate, the black matrix layer has a thickness of 0.5 to 3 μm and a width of 3 to 30 μm. Moreover, each film thickness of a red pixel, a green pixel, and a blue pixel is 0.5-3 micrometers. This film thickness largely depends on the composition of the photosensitive coloring composition and the coating method, but when the film thickness of each pixel is formed at about 1.8 μm using a conventional photosensitive coloring composition, for example, The thickness of the red layer (4R) that rides on and forms on the black matrix (2) is about 1.40 μm, and the thickness of the green layer (4G) that rides on and forms on it is about 0.95 μm. The thickness of the blue layer (4B) that rides on and is formed tends to be as thin as about 0.88 μm.

  The transparent substrate used in the color filter of the present invention preferably has a certain transmittance with respect to visible light, and more preferably has a transmittance of 80% or more. Generally, it may be one used in a liquid crystal display device, and examples thereof include a plastic substrate such as PET and glass, but a glass substrate is usually used.

  The black matrix layer is a thin light-shielding pattern formed between each pixel for increasing the contrast of a liquid crystal display device formed using a black resin. As a method for forming the black matrix layer, a protective resist is formed by a photolithography method using a black non-photosensitive resin and formed into a matrix by etching, or a matrix is formed by a photolithography method using a black photosensitive resin. There is a method of forming. As the black color material, carbon black, titanium oxide, or a plurality of organic pigments can be used.

  As a method for forming colored pixels and a black matrix on a transparent substrate, a pigment dispersion method has become the mainstream. In the pigment dispersion method, a color filter is formed of a plurality of colored layers (red, green, blue, etc.) by patterning a coating layer of a photosensitive coloring composition in which a coloring material such as an organic pigment is dispersed by a known photolithography method. This is a method of forming a pixel. Although the order of coloration of the plurality of colored layers is not limited, the colored pixels (red pixels, Green pixels, blue pixels, etc.) are formed in sequence, and a laminated photo spacer having a desired height is formed simultaneously with the pixel formation.

  In the case where a colored layer is used as a spacer, the stacked portion is formed by stacking one or more colored layers on the black matrix layer. The number of colors to be superimposed is defined by the cell gap necessary for the liquid crystal display device, but preferably two to three colors. In the case of stacking two colors, when the red and blue colored layers are stacked, the color becomes close to black, which prevents color mixture in the pixel portion when color misregistration occurs. Alternatively, by using two types of laminated portions of two colors and three colors, the lower laminated portion can be used as a sub-spacer. The sub-spacer serves as a spacer for preventing cell destruction when a large pressure is applied to the liquid crystal panel during use as a display device. The formation ratio of the spacer and the sub-spacer is not limited, but about 1: 2 (the latter is the sub-spacer) is practical. Alternatively, for example, it is possible to form a laminated portion of two colors and use it as a spacer or a sub-spacer depending on whether or not a protrusion is further formed on the laminated portion.

  In the color filter substrate according to the present invention, a transparent protective layer may be formed on the colored pixels and the laminated photospacer portion. For liquid crystals that require electric field driving in the thickness direction of the liquid crystal cell gap by transparent electrodes, such as vertically aligned liquid crystal, liquid crystal called OCB (Optically Compensated Birefringence), ferroelectric liquid crystal, and liquid crystal called ECB (Electrically Controlled Birefringence) A step of forming a transparent conductive film can be added after the step of forming the pixel and the laminated photospacer and the step of forming the transparent protective layer. In this case, an insulating layer is formed on the transparent electrode on the laminated layer or at a site where the spacer of the counter substrate contacts. This insulating layer may be formed at the same time as the alignment regulating protrusion for the purpose of regulating liquid crystal alignment (alignment control) such as viewing angle and responsiveness improvement. For example, in the case of an IPS (lateral electric field) type liquid crystal display device which does not require the formation of a transparent conductive film as a color filter substrate, the insulating layer can be omitted.

The transparent conductive film is provided on the color filter layer and is made of a transparent and conductive material that can be formed into a thin film. Usually, an ITO (complex oxide of indium and tin) film is used, and the other is IZO (indium). And a composite oxide of zinc and SnO ₂ (tin dioxide) are selected, and can be formed by a general film forming method such as a sputtering method, a PVD method such as a vacuum evaporation method, or a CVD method.

  An embodiment according to the present invention will be described below with reference to FIG. In addition, this invention is not limited to a following example, unless the summary is exceeded. In Examples and Comparative Examples, “parts” and “%” mean “parts by mass” and “% by mass”, respectively.

  A black matrix, red (R), green (G), and blue (B) colored pixels were provided on a 0.7 mm thick glass substrate. In the following examples and comparative examples, in order to clarify the effects of the present invention, only the blue colored composition is applied, and the color filter has a laminated portion in which the blue colored composition is laminated on a black matrix. Was made.

  First, the preparation of the photosensitive coloring composition used in Examples and Comparative Examples will be specifically described. The present invention is not limited to these examples, and various modifications can be made without departing from the spirit of the present invention.

[Synthesis of photopolymerizable monomer]
(Photopolymerizable monomer 1)
623 g of dipentaerythritol hexaacrylate (manufactured by Toagosei Co., Ltd.) and 44 g of hexamethylene diisocyanate were charged into a 5-neck reaction vessel having an internal volume of 1 liter, and reacted at 60 ° C. for 8 hours to obtain a photopolymerizable monomer 1. It was confirmed by the IR analysis that no isocyanate group was present in the reaction product.

(Photopolymerizable monomer 2)
In a four-necked flask having an internal volume of 1 liter, 578 parts of dipentaerythritol hexaacrylate (manufactured by Toagosei Co., Ltd.), 20 parts of mercaptoacetic acid, 0.5 part of N, N-dimethylbenzylamine and 4-methoxyphenol. 6 parts were charged and reacted at a temperature of 50 to 60 ° C. for 6 hours to obtain a photopolymerizable monomer 2 containing a carboxyl group-containing polyfunctional monomer.

(Photopolymerizable monomer 3)
A five-necked reaction vessel with an internal volume of 1 liter was charged with 284 g of glycidyl methacrylate, 144 g of acrylic acid, 0.4 g of methoxyphenol, and 5 g of triphenylphosphine, and reacted at 80 ° C. for 12 hours to give 2-hydroxy-3-acryloyl Propyl methacrylate was obtained. Further, 168 g of hexamethylene diisocyanate was added thereto and reacted at 60 ° C. for 8 hours to obtain a photopolymerizable monomer 3. It was confirmed by the IR analysis that no isocyanate group was present in the reaction product.

[Preparation of acrylic resin solution]
Place 370 parts of cyclohexanone in a reaction vessel equipped with a thermometer, a cooling tube, a nitrogen gas inlet tube, and a stirrer in a separable four-necked flask, and heat to 80 ° C. while injecting nitrogen gas into the vessel. 23 parts of acid (MAA), 17 parts of 2-hydroxyethyl methacrylate (HEMA), 25 parts of n-butyl methacrylate (BMA), 22 parts of benzyl methacrylate (BzMA), paracumylphenol ethylene oxide modified acrylate (“Aronix” manufactured by Toagosei Co., Ltd.) M110 ") and 13 parts of 2,2'-azobisisobutyronitrile (12.0 parts) were added dropwise over 1 hour to conduct a polymerization reaction. After completion of the dropwise addition, the mixture was further reacted at 80 ° C. for 3 hours, and then a solution in which 3.0 parts of azobisisobutyronitrile was dissolved in 50 parts of cyclohexanone was added, and the reaction was further continued at 80 ° C. for 1 hour. A solution was obtained. 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 mass. An acrylic resin solution was prepared.

[Preparation of pigment dispersion]
・ Red pigment dispersion PR
A mixture having the following composition was stirred and mixed uniformly, then dispersed in a sand mill for 5 hours using glass beads having a diameter of 1 mm, and then filtered through a 5 μm filter to prepare a red pigment dispersion PR.
Red pigment: C.I. I. Pigment Red 254
(“Ilgar For Red B-CF” manufactured by Ciba Japan) 9 parts Red pigment: C.I. I. Pigment Red 177
(“Chromophthal Red A2B” manufactured by Ciba Japan Co., Ltd.) 1 part Dispersant (“Solsperse 20000” manufactured by Nippon Lubrizol) 2 parts Acrylic resin solution (solid content 20%) 40 parts 48 parts propylene glycol monomethyl ether acetate

・ Green pigment dispersion PG
A mixture of the following composition was uniformly stirred and mixed, then dispersed in a sand mill for 5 hours using glass beads having a diameter of 1 mm, and then filtered through a 5 μm filter to prepare a green pigment dispersion PG.
Green pigment: C.I. I. PigmentGreen 36
(“Lionol Green 6Y501” manufactured by Toyo Ink Co., Ltd.) 14 parts Dispersant (“Disperbyk-163” manufactured by Big Chemie) 2 parts Acrylic resin solution (solid content 20%) 20 parts Propylene glycol monomethyl ether acetate 64 parts

・ Yellow pigment dispersion PY
A mixture having the following composition was uniformly stirred and mixed, then dispersed in a sand mill for 5 hours using glass beads having a diameter of 1 mm, and then filtered through a 5 μm filter to prepare a yellow pigment dispersion PY.
Yellow pigment: C.I. I. Pigment Yellow 150
(“E4GN” manufactured by LANXESS) 10 parts Dispersant (“Disperbyk-163” manufactured by Big Chemie) 2 parts Acrylic resin solution (solid content 20%) 40 parts Propylene glycol monomethyl ether acetate 48 parts

・ Blue pigment dispersion PB
A mixture having the following composition was stirred and mixed uniformly, then dispersed in a sand mill for 5 hours using glass beads having a diameter of 1 mm, and then filtered through a 5 μm filter to prepare a blue pigment dispersion PB.
Blue pigment: C.I. I. PigmentBlue 15: 6
(“Lionol Blue ES” manufactured by Toyo Ink Co., Ltd.) 9.6 parts Purple pigment: C.I. I. PigmentViolet 23
(BASF "Paliogen Violet 5890") 0.4 parts Dispersant (Zeneca "Sols Birds 20000") 2 parts Acrylic resin solution (solid content 20%) 40 parts Propylene glycol monomethyl ether acetate 48 parts

[Production of photosensitive coloring composition]
-Red photosensitive coloring composition After stirring and mixing the mixture of the following composition uniformly, it filtered with a 1 micrometer filter, and obtained the red photosensitive coloring composition.
Red dispersion PR 57 parts Acrylic resin solution (solid content 20%) 18.3 parts Photopolymerizable monomer (“Aronix M402” manufactured by Toa Gosei Co., Ltd. 2.8 parts Photoinitiator (“Irgacure 379” manufactured by Ciba Japan) 0.8 parts Sensitizer ("EAB-F" manufactured by Hodogaya Chemical Co., Ltd.) 0.3 parts Cyclohexanone 20.7 parts

-Green photosensitive coloring composition After stirring and mixing the mixture of the following composition uniformly, it filtered with a 1 micrometer filter, and obtained the green photosensitive coloring composition.
Green pigment dispersion PG 43.4 parts Yellow pigment dispersion PY 15.2 parts Acrylic resin solution (solid content 20%) 20.4 parts Photopolymerizable monomer ("Aronix M402" manufactured by Toagosei Co., Ltd.) 2.5 parts Light Initiator ("Irgacure 379" manufactured by Ciba Japan) 0.6 parts 0.15 part of photoinitiator ("Irgacure OXE-02" manufactured by Ciba Japan)
Propylene glycol monomethyl ether acetate 20.25 parts

-Blue photosensitive coloring composition After stirring and mixing the mixture of composition (mass ratio) shown in Table 1 so that it might become uniform, it filtered with a 1 micrometer filter, and Examples 1-4 and Comparative Examples 1-4 were used. Each blue photosensitive coloring composition was prepared.

The specific contents of the composition in Table 1 are shown below.
-Pigment dispersion: Blue pigment dispersion PB prepared earlier
-Transparent extender: "Organosilica sol: PMA-ST" manufactured by Nissan Chemical Co., Ltd.
-Post-added resin: previously prepared acrylic resin solution (solid content 20%)
Photopolymerizable monomer: Photopolymerizable monomer 1 prepared previously (80% solid content)
: Photopolymerizable monomer 2 prepared previously (solid content: 70%)
: Photopolymerizable monomer 3 prepared in advance (solid content: 70%)
: "Aronix M402" manufactured by Toa Gosei Co., Ltd.
Photoinitiator: “Irgacure 379” manufactured by Ciba Japan
・ Sensitizer: “EAB-F” manufactured by Hodogaya Chemical Co., Ltd.
・ Sensitizer: “DAROCUR TPO” manufactured by Ciba Japan
・ Surfactant: BYK330 “BYK330” 2% cyclohexanone solution ・ Organic solvent: Propylene glycol monomethyl ether acetate (PGMAC)
Organic solvent: Ethyl-3-ethoxypropionate (EEP)
Organic solvent: cyclohexanone

[Colored pixels, spacer formation]
A colored pixel layer was formed using the obtained photosensitive coloring composition. A red photosensitive coloring composition is formed to 2.3 μm by spinless coating on a glass substrate on which a stripe-shaped resin black matrix in which only the laminated portion is partially widened is formed in advance with a film thickness of 1.9 μm. It applied so that it might become. After drying at 90 ° C. for 5 minutes, light from a high-pressure mercury lamp is irradiated through a striped photomask for forming red pixels at 300 mJ / cm ² and developed with an alkali developer for 60 seconds. Colored pixels were obtained. Then, it hardened | cured by processing for 30 minutes at 230 degreeC.

  Next, the green photosensitive coloring composition was similarly applied by spinless coating so that the finished film thickness was 2.3 μm. After drying at 90 ° C. for 5 minutes, green pixels were obtained by exposing and developing through a photomask so that a pattern was formed adjacent to the red pixels. Then, it hardened | cured by processing for 30 minutes at 230 degreeC.

  Further, in the same manner as red and green, the blue photosensitive coloring composition was similarly applied by spinless coating so that the finished film thickness was 2.6 μm. After drying at 90 ° C. for 5 minutes, the blue pixels and the black matrix are exposed and developed through a photomask so that a colored pattern is formed adjacent to the red and green colored pixels and a laminated pattern is formed on the black matrix. An upper dot-like laminate having a diameter of 52 μm was obtained. Then, it hardened | cured by processing for 30 minutes at 230 degreeC. Thus, a color filter having striped colored pixels of three colors of red, green, and blue on a transparent substrate and a laminated photo spacer made of a blue photosensitive coloring composition on a black matrix was obtained.

The alkaline developer has the following composition.
Sodium carbonate 1.5% by mass
Sodium bicarbonate 0.5% by mass
Anionic surfactant (Kao Perillex NBL) 8.0% by mass
90.0% by mass of water

[Evaluation]
The blue photosensitive coloring compositions of Examples 1 to 4 and Comparative Examples 1 to 4 were evaluated according to the following procedures.

<Measurement of ride rate>
About the color filter produced using the blue photosensitive coloring composition of Examples 1-4 and Comparative Examples 1-4, as shown in FIG. 2, the film thickness (a = 2.6 micrometer) of a blue pixel, and a black matrix The film thickness of the upper dot-shaped laminated portion = the amount of ride (b) was measured with a contact-type film thickness meter. Moreover, the boarding rate (b / a) was calculated.

<Peeling development>
The development process in pattern formation of the blue photosensitive coloring compositions of Examples 1 to 4 and Comparative Examples 1 to 4 was observed, and it was rated as ○ if it was uniformly dissolved, and x if it was peeled off.

<Storage stability>
For the blue photosensitive coloring compositions of Examples 1 to 4 and Comparative Examples 1 to 4, the viscosity before and after the accelerated aging test at 40 ° C. for 7 days was measured. X was also large. The evaluation results are shown in Table 2 below.

<Evaluation results>
From the results shown in Table 2, in the photosensitive coloring composition using a monomer having a molecular weight of 1000 or less, such as the commonly used monomer M402, in the comparative example, the transparent development pigment is contained so that the peeling development can be performed. Occurrence has been seen. By adjusting the molecular weight of the monomer to the range of 1000 to 1500, it is confirmed that the release development is eliminated and the running rate is improved. On the other hand, in the case of a monomer having a molecular weight of 1500 or more, an improvement in the running rate has been confirmed, but storage stability is deteriorated. In addition, as the amount of the transparent extender pigment increases, the running rate tends to increase. However, the storage stability and the tendency to exacerbate the peeling development are seen correspondingly, and when the amount exceeds 10% by mass, the molecular weight of the present invention is increased. Even if a monomer within the range is used, the peeling development occurs.

  From the above, in the color filter formed using the photosensitive coloring composition of the present invention, the film thickness of the blue photosensitive coloring composition formed and formed on the black matrix portion is not deteriorated without deterioration in peeling development and storage stability. Since the rise rate compared to the film thickness of the flat part of the pixel becomes large, it is possible to obtain the required laminated photo spacer height with a thin colored film or with a photosensitive colored composition with a small number of colors. Become.

DESCRIPTION OF SYMBOLS 1 ... Glass substrate 2 ... Black matrix 3R ... Red pixel 3G ... Green pixel 3B ... Blue pixel 4, 4R, 4G, 4B ... Laminated photo spacer 5 ... Transparent electrode (ITO film)

Claims (3)

  Color filter comprising a black matrix on a transparent substrate, a plurality of colored pixels made of a photosensitive coloring composition, and a laminated photo spacer formed by laminating one or more colors of the photosensitive coloring composition on the black matrix. A photosensitive coloring composition for a substrate, wherein the photosensitive coloring composition contains at least a colorant, a transparent extender pigment, a transparent resin, a photopolymerizable monomer, and a photopolymerization initiator. A photosensitive coloring composition containing 1 to 10% by mass of a transparent extender pigment in the total solid content, and having a molecular weight of 1000 to 1500 in the photopolymerizable monomer.   2. The photosensitive material according to claim 1, wherein the transparent extender pigment is at least one selected from the group consisting of silicon oxide, barium sulfate, titanium oxide, zinc oxide, aluminum oxide, magnesium oxide, calcium carbonate, and magnesium carbonate. Coloring composition.   A color filter substrate comprising a colored pixel and a laminated photospacer formed using the photosensitive coloring composition according to claim 1.