JP2009300564A - Photosensitive colored composition, and color filter and liquid crystal display device using this - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition for a colored layer that has high adhesiveness with thermosetting overcoat layer and is applied in order to flatten the surface of a color filter having coloring pixels of at least three colors of red (R), green (G), and blue (B) on a transparent substrate, to provide the color filter, and also to provide a liquid crystal display device causing no liquid crystal orientation turbulence and having high display characteristics. <P>SOLUTION: This photosensitive resin composition for the color filter contains (1) photopolymerization monomer, (2) non-photosensitive resin and/or photosensitive resin, (3) a photopolymerization initiator, (4) a coloring agent, and (5) a solvent. The mass content ratio (monomer/resin) between (1) photopolymerization monomer and (2) non-photosensitive resin and/or photosensitive resin is between 0.75 and 2.0, and the pure water contact angle of an applied film after curing by optical irradiation and/or firing is between 75° and 100°. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a photosensitive coloring composition for a color filter coloring layer, a color filter using the same, and a liquid crystal display device including the same.

  A color liquid crystal display device is generally configured by sealing liquid crystal between a color filter and a TFT array substrate. The color filter includes a transparent substrate as a structural support, and a polarizing film is laminated on the screen observer side. The opposite side (back side) is divided into a large number of pixel regions. A black matrix in which a black color material is dispersed in an organic resin is provided at a portion between pixels located at the boundary between the pixel region and a colored pixel is disposed in each pixel region. The black matrix is disposed between the colored pixels for the purpose of improving contrast. The colored pixels color the transmitted light for each pixel, and generally, three colored pixels of red (R), green (G), and blue (B) corresponding to the three primary colors of light are arranged. Note that the black matrix prevents color mixing of transmitted light colored in these colors.

  In the color filter manufacturing process, after a black matrix pattern is formed on a transparent substrate, colored pixels are colored in the order of red, green, and blue. A step (horn step) with the part occurs. If a color filter with a deteriorated surface flatness is used in a liquid crystal display device, the alignment of liquid crystal molecules is disturbed by the influence of protrusions, causing light leakage and degrading the display quality of the liquid crystal display device.

In order to deal with such a problem, Patent Document 1 discloses that even if a color filter having colored protrusions is formed on a color filter having a thick projection using a thick positive photosensitive resin, A technique for forming an overcoat layer having excellent smoothness is disclosed. That is, it is a technique for forming a transparent resin layer on a colored pixel formed of a photosensitive coloring composition and flattening a step on the surface of the color filter. However, the color pixel swells in the solvent of the overcoat agent, or conversely, the adhesion between the overcoat layer and the color pixel is poor, and there is a problem that peeling occurs when a peel test is performed. Such swelling and peeling should not be present in liquid crystal display devices that require higher quality and higher reliability, and improvements in solvent resistance and adhesion are required.
JP 2002-228826 A

  The present invention has been made in view of the above circumstances, and planarizes the surface of a color filter having at least three colored pixels of red (R), green (G), and blue (B) on a transparent substrate. It is an object to provide a photosensitive resin composition for a color filter colored layer and a color filter, which have good adhesion to a thermosetting overcoat layer, which is applied, and does not peel at all by a peel test In addition, it is an object of the present invention to provide a liquid crystal display device having good display characteristics free from liquid crystal alignment disorder.

  As a result of intensive studies, the present inventors have found that the content mass ratio (monomer / resin) of the photopolymerizable monomer and the non-photosensitive resin and / or the photosensitive resin is 0.75 or more and 2.0 or less, and light The present invention has found that the above-mentioned problems can be solved by using a photosensitive coloring composition having a pure water contact angle of 75 ° C. or more and 100 ° or less after being cured by irradiation and / or baking. Was completed.

  The invention according to claim 1 of the present invention comprises (a) a photopolymerizable monomer, (b) a non-photosensitive resin and / or a photosensitive resin, (c) a photopolymerization initiator, (d) a colorant, and (e) In the photosensitive coloring composition for a color filter comprising a solvent, the content mass ratio (monomer / resin) of (a) a photopolymerizable monomer and (b) a non-photosensitive resin and / or a photosensitive resin. ) Is 0.75 or more and 2.0 or less, it is the photosensitive coloring composition for color filters characterized by the above-mentioned.

  The invention according to claim 2 of the present invention is the photosensitive coloring composition for color filters according to claim 1, wherein the (d) colorant is a red pigment.

Next, the invention according to claim 3 of the present invention is the color filter having at least a black matrix and a plurality of colored pixels on a transparent substrate, and photosensitive coloring for a color filter according to claim 1 or 2. The color filter is characterized in that the contact angle of the colored pixels formed by the composition is 75 degrees or more and 100 degrees or less.
Here, the contact angle is a contact angle at room temperature with respect to pure water, which is determined by a sessile drop method defined in 6 of JIS R3257.

  The invention according to claim 4 of the present invention is the color filter according to claim 3, wherein one color of the colored pixels of the plurality of colors is a red pixel.

  According to a fifth aspect of the present invention, there is provided a liquid crystal display device comprising the color filter according to the third or fourth aspect.

  It is generally known that when the photosensitive coloring composition applied on the transparent substrate is cured by light irradiation, the surface curing is hindered by oxygen contained in the atmosphere. According to the invention, since the photosensitive coloring composition having a high photopolymerizable monomer content is used, oxygen inhibition is alleviated and surface hardening can be promoted. By sufficiently curing the surface, the solvent resistance is improved, and the disturbance of the interface between the overcoat material and the colored pixels is eliminated, resulting in good adhesion. Here, when the monomer / resin ratio is less than 0.75, the adhesiveness with the overcoat layer is lowered, and when it exceeds 2.0, for example, 2.1 or more, the developability of the photosensitive coloring composition is lowered. Alternatively, when the pattern is formed, the shape may be loose or overhang, which is not preferable. The present invention is highly effective in improving the adhesion between the red colored pixel and the overcoat layer.

  Further, as the surface hardening progresses, the surface becomes more hydrophobic and the contact angle becomes higher, that is, the surface becomes hydrophobic, so that it becomes easy to become familiar with an organic overcoat material, and the contact angle of the colored pixel is 75 degrees. The adhesiveness is improved as described above. When the contact angle exceeds 100 degrees, for example, 110 degrees or more, there is a tendency that repellence starts to occur when the overcoat material is applied and formed.

  By using the photosensitive coloring composition of the present invention, the adhesiveness with the overcoat layer applied in order to relieve the step (horn step) from the pixel center caused by the overlapping of the colored pixel ends is good. Colored pixels that do not peel off can be formed, and a liquid crystal display device free from light leakage can be provided. In other words, a higher image quality and higher reliability of the liquid crystal display device can be provided by improving the adhesion between the colored pixel and the overcoat layer.

  Furthermore, the present invention provides adhesion between a spacer formed directly on a color filter and a colored pixel for a color filter having a structure in which an overcoat layer and a transparent electrode called ITO are not laminated, for example, a lateral electric field method (IPS method). It is also effective for improving.

  The photosensitive coloring composition of this invention, a color filter using the same, and a liquid crystal display device are demonstrated in detail below based on one Embodiment. First, the material constituting the photosensitive coloring composition for a color filter will be described.

(Photopolymerizable monomer)
Examples of photopolymerizable monomers include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, cyclohexyl (meth) acrylate, polyethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylol Various acrylic and methacrylic acid esters such as propane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tricyclodecanyl (meth) acrylate, melamine (meth) acrylate, epoxy (meth) acrylate, (meth) Examples include acrylic acid, styrene, vinyl acetate, (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, and acrylonitrile. Moreover, it is preferable to use the polyfunctional urethane acrylate which has the (meth) acryloyl group obtained by making polyfunctional isocyanate react with the (meth) acrylate which has a hydroxyl group. The combination of the (meth) acrylate having a hydroxyl group and the polyfunctional isocyanate is arbitrary and is not particularly limited. Moreover, one type of polyfunctional urethane acrylate may be used alone, or two or more types may be used in combination.

(Non-photosensitive resin and / or photosensitive resin)
As the non-photosensitive resin and / or the photosensitive resin used for the constituent material of the photosensitive coloring composition of the present invention, the transmittance is preferably 80% or more, more preferably in the entire wavelength region of 400 to 700 nm in the visible light region. 95% or more of a thermoplastic resin, a thermosetting resin, and a photosensitive resin can be used. For the non-photosensitive resin and / or the photosensitive resin, if necessary, a precursor or a monomer or oligomer that is cured by radiation irradiation to form a resin is used alone or in combination of two or more. Can do.

  Examples of the plastic resin include butyral resin, styrene-maleic acid copolymer, chlorinated polyethylene, chlorinated polypropylene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyurethane resin, polyester resin, Examples include 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.

(Coloring agent)
The colorant is for coloring the display light of the liquid crystal display device by coloring the transparent non-photosensitive resin and / or the photosensitive resin film, and using a pigment or a dye, respectively, or using them together. However, it is desirable to use a pigment because of its excellent durability. The pigment may be either an organic pigment or an inorganic pigment, but an organic pigment can be preferably used. Moreover, although the compounding quantity is not specifically limited, It is preferable that it is about 5-70 mass% with respect to 100 mass% of total amounts of a composition, and it is more preferable that it is about 5-50 mass%. More preferably, the amount is about 20 to 50% by mass, and the remainder substantially consists of a non-photosensitive resin and / or a photosensitive resin provided by the pigment carrier. Also, a plurality of pigments can be used in combination for spectral adjustment of the color filter.

Specific examples of the organic pigment for the colored layer that can be used in combination with the non-photosensitive resin and / or the photosensitive resin used as the constituent material of the photosensitive coloring composition of the present invention are shown by color index (CI) numbers. .
Pigment Red: <C. I> 1, 2, 3, 4, 5, 6, 7, 9, 10, 14, 17, 22, 23, 31, 38, 41, 48: 1, 48: 2, 48: 3, 48: 4 49, 49: 1, 49: 2, 52: 1, 52: 2, 53: 1, 57: 1, 60: 1, 63: 1, 66, 67, 81: 1, 81: 3, 81: x, 83, 88, 90, 97, 112, 119, 122, 123, 144, 146, 149, 166, 168, 169, 170, 171, 172, 175, 176, 177, 178, 179, 180, 184, 185 187,188,190,192,200,202,206,207,208,209,210,215,216,217,220,223,224,226,227,228,240,246,254,255,264 272, 279
Further, in combination with the organic pigment, an inorganic pigment can be used in combination in order to ensure good coatability, sensitivity, developability, and the like while balancing saturation and lightness. Inorganic pigments include yellow lead, zinc yellow, red bean (red iron oxide (III)), cadmium red, ultramarine, bitumen, chromium oxide green, cobalt green and other metal oxide powders, metal sulfide powders, metal powders, etc. Can be mentioned. Furthermore, for color matching, it is also possible to add a dye within a range that does not lower the heat resistance.

(Dispersant)
When the pigment is dispersed in the pigment carrier and the organic solvent, it is necessary to contain a dispersant for dispersing the pigment and a surfactant. Surfactants, pigment intermediates, dye intermediates, Solsperse, and the like are used as the dispersant, and have a pigment affinity part having a property of adsorbing to the pigment and a part compatible with the pigment carrier. It functions to adsorb to the pigment and stabilize the dispersion of the pigment on the pigment carrier. Specifically, polycarboxylic acid esters such as polyurethane and polyacrylate, unsaturated polyamide, polycarboxylic acid, polycarboxylic acid (partial) amine salt, polycarboxylic acid ammonium salt, polycarboxylic acid alkylamine salt, polysiloxane, long Oil-based dispersants such as chain polyaminoamide phosphates, hydroxyl group-containing polycarboxylic acid esters, their modified products, amides formed by the reaction of poly (lower alkyleneimines) and polyesters having free carboxyl groups, and salts thereof , (Meth) acrylic acid-styrene copolymer, (meth) acrylic acid- (meth) acrylic acid ester copolymer, styrene-maleic acid copolymer, polyvinyl alcohol, polyvinylpyrrolidone, and other water-soluble resins Molecular compound, 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. Although the addition amount of a dispersing agent is not specifically limited, It is preferable to set it as 1-10 mass% with respect to 100 mass% of compounding quantities of a pigment. Further, the coloring composition may be obtained by means of centrifugal separation, a sintered filter, a membrane filter, or the like, with 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.

(Surfactant)
Surfactants include polyoxyethylene alkyl ether sulfate, sodium dodecylbenzenesulfonate, alkali salt of styrene-acrylic acid copolymer, sodium alkylnaphthalenesulfonate, sodium alkyldiphenyletherdisulfonate, lauryl sulfate monoethanolamine, lauryl Anionic surfactants such as triethanolamine sulfate, ammonium lauryl sulfate, monoethanolamine stearate, sodium stearate, sodium lauryl sulfate, monoethanolamine of styrene-acrylic acid copolymer, polyoxyethylene alkyl ether phosphate; Polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene Nonionic surfactants such as alkyl ether phosphates, polyoxyethylene sorbitan monostearate, and polyethylene glycol monolaurate; chaotic surfactants such as alkyl quaternary ammonium salts and their ethylene oxide adducts; alkyldimethylamino Examples include amphoteric surfactants such as alkylbetaines such as betaine acetate and alkylimidazolines, and these can be used alone or in admixture of two or more.

(Photopolymerization initiator)
Examples of the photopolymerization initiator include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- Acetophenone compounds such as hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl Benzoin compounds such as dimethyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4 ' -Benzophenone compounds such as methyldiphenyl sulfide, thioxanthone compounds such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, 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-pienyl-4,6-bis (trichloromethyl) -s-triazine, 2,4-bis (trichloromethyl) -6-styryl s-triazine, 2- (naphth-1-yl) -4,6-bis (trichloromethyl) -s-tri Gin, 2- (4-methoxy-naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, 2,4-trichloro Triazine compounds such as methyl (4′-methoxystyryl) -6-triazine, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], O- (acetyl) Oxime ester compounds such as -N- (1-phenyl-2-oxo-2- (4'-methoxy-naphthyl) ethylidene) hydroxylamine, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, 2, Phosphine compounds such as 4,6-trimethylbenzoyldiphenylphosphine oxide, 9,10-phenanthrenequinone, camphor Quinones, quinone-based compounds such as ethyl anthraquinone, borate compounds, carbazole compounds, imidazole compounds, titanocene compounds, and the like. These can be used singly or in combination of two or more.

(Photosensitizer)
Moreover, it is preferable to use a photoinitiator and a photosensitizer together. As photosensitizer, α-acyloxy ester, acylphosphine oxide, 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. The photosensitizer can be contained in an amount of 0.1 to 60 parts by mass with respect to 100 parts by mass of the photopolymerization initiator.

(Multifunctional thiol)
Furthermore, the photosensitive coloring composition 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, trimercaptopropionic acid tris (2-hydroxyethyl) isocyanurate, 1,4-dimethylmercaptobenzene, 2,4,6-trimercap -s- triazine, 2- (N, N- dibutylamino) -4,6-dimercapto -s- triazine. These polyfunctional thiols can be used alone or in combination. The polyfunctional thiol can be used in an amount of 0.2 to 150 parts by mass, preferably 0.2 to 100 parts by mass with respect to 100 parts by mass of the pigment in the photosensitive coloring composition.

(Storage stabilizer)
The photosensitive coloring composition can contain a storage stabilizer in order to stabilize the viscosity with time of the composition. Examples of the storage stabilizer 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, triethylphosphine, and triphenylphosphine. Examples thereof include phosphine and phosphite. The storage stabilizer can be contained in an amount of 0.1 to 10 parts by mass with respect to 100 parts by mass of the pigment in the photosensitive coloring composition.

(Adhesion improver)
Moreover, in order to improve the adhesiveness with a board | substrate, the photosensitive coloring composition can also contain adhesion | attachment improvement agents, such as a silane coupling agent. 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 silane coupling agent can be contained in an amount of 0.01 to 100 parts by mass with respect to 100 parts by mass of the pigment in the photosensitive coloring composition.

(solvent)
The photosensitive coloring composition is mixed with a solvent such as water or an organic solvent in order to enable uniform coating on the substrate. Moreover, when the photosensitive coloring composition of this invention is a colored layer of a color filter, a solvent also has the function to disperse | distribute a pigment uniformly. 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 A solvent etc. are mentioned, These are used individually or in mixture. The solvent can be used in an amount of 800 to 4000 parts by mass, preferably 1000 to 2500 parts by mass with respect to 100 parts by mass of the pigment in the coloring composition.

[Method for preparing photosensitive coloring composition]
The photosensitive coloring composition can be prepared by a known method. For example, (1) a pigment composition prepared by previously mixing a pigment and a dispersant is added to a solution in which a photopolymerizable monomer is dissolved in a solvent and dispersed, and the remaining components are added. (2) A pigment and a dispersant are separately added and dispersed in a solution in which a photopolymerizable monomer is dissolved in a solvent, and then the remaining components are added. (3) A pigment is dispersed in a solution in which a photopolymerizable monomer is dissolved in a solvent, a pigment dispersant is added, and the remaining components are added. (4) There is a method in which a pigment and a dispersant are separately dispersed in advance, and then mixed with a solution in which a photopolymerizable monomer is dissolved in a solvent, and the remaining components are added. One of the pigment and the dispersant may be dispersed only in the solvent.

  Here, dispersion of pigments and dispersants in a solution in which a photopolymerizable monomer is dissolved in a solvent is various dispersions such as a three roll mill, a two roll mill, a sand mill, a kneader, a dissolver, a high speed mixer, a homomixer, and an attritor. This can be done using an apparatus. Moreover, in order to perform dispersion | distribution favorably, you may add and disperse | distribute various surfactants. In addition, when preparing a pigment composition by previously mixing a pigment and a dispersant, the powder pigment and the powder dispersant may be simply mixed, but (a) a kneader, a roll, an attritor, a super mill, etc. Mix mechanically with various pulverizers, (b) Disperse the pigment in the solvent, add a solution containing the dispersant, and adsorb the dispersant on the pigment surface. (C) Strong dissolving power such as sulfuric acid It is preferable to employ a mixing method in which the pigment and the dispersant are co-dissolved in the solvent that is held and then co-precipitated using a poor solvent such as water.

[Color filter]
Hereinafter, a method for forming a color filter color layer (color pixel) will be described. Note that a counter substrate support layer (spacer) for uniformizing the cell gap of the liquid crystal display device, a raised layer for controlling the cell gap, and a position formed on the surface of the substrate on which the colored layer (colored pixel) is provided. A similar forming method can be applied to the phase difference layer.

  Fig.1 (a) is a schematic sectional drawing of an example of the color filter of this invention. A black matrix 2 formed by patterning a metal such as chromium or a photosensitive black resin composition is formed on the substrate 1 by a known method. As the substrate 1 to be used, a transparent substrate is preferable, and specifically, a glass substrate, a resin substrate such as polycarbonate, polymethyl methacrylate, polyethylene phthalate is preferably used. In addition, a transparent electrode made of a combination of metal oxides such as indium oxide, tin oxide, zinc oxide and antimony oxide is formed on the surface of the glass plate or resin plate for driving the liquid crystal after the liquid crystal panel is formed. Also good.

First, the photosensitive coloring composition of the present invention is uniformly applied on the substrate 1 by a spray coating method, a spin coating method, a roll coating or the like and dried. The layer formed in this step is referred to as “photosensitive composition layer”. Next, the formed photosensitive composition layer is patterned by photolithography. That is, exposure is performed by irradiating active energy rays such as ultraviolet rays and electron beams through a photomask having a desired light-shielding pattern, and then development is performed using a developer such as an organic solvent or an alkaline aqueous solution. Here, in the exposure step, the photopolymerizable monomer in the portion irradiated with the active energy ray is polymerized and cured. Further, when a photosensitive resin is contained, the resin is also crosslinked and cured.

  In order to improve exposure sensitivity, after forming a photosensitive composition layer, a solution of water-soluble or alkaline water-soluble resin (for example, polyvinyl alcohol, water-soluble acrylic resin, etc.) is applied and dried. Exposure may be performed after forming a film that suppresses polymerization inhibition.

  Then, in the development process, a desired pattern is formed by washing away a portion that has not been irradiated with the active energy ray with a developer. 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. As the developer, an alkaline developer such as an aqueous solution such as sodium carbonate or caustic soda, or an organic alkali solution such as dimethylbenzylamine or triethanolamine is mainly used. Moreover, as a developing solution, what added the antifoamer and surfactant was used as needed.

  Finally, baking is performed, and the same operation is repeated for other colors to produce a color filter. That is, the colored layer 3 on the substrate and / or the counter substrate carrying layer (spacer) 4 formed on the surface of the substrate on which the colored layer is provided to make the cell gap of the liquid crystal display device uniform is formed. be able to. FIG. 1B is a schematic cross-sectional view of another example of the color filter of the present invention. Here, an overcoat layer 6 laminated on the substrate surface provided with the colored layer 3 and a spacer 4 for making the cell gap of the liquid crystal display device uniform are shown.

[Overcoat material]
The overcoat material applicable to the color filter of the present invention may be an organic material that can withstand the liquid crystal panel process and has reliability such as transparency and heat resistance. Commercially available representative overcoat materials such as Optomer SS manufactured by JSR, NOFCURE OP manufactured by Nippon Oil & Fats, V-259PA manufactured by Nippon Steel Chemical Co., Ltd., KAYADAD manufactured by Nippon Kayaku Co., Ltd. and the like can be applied.

  Next, a liquid crystal display device provided with the color filter of the present invention will be described.

  FIG. 2 shows a schematic sectional view of an example of the liquid crystal display device 7 provided with the color filter of the present invention. The liquid crystal display device 7 is a typical example of a TFT drive type liquid crystal display device for a notebook personal computer, and includes a pair of transparent substrates 8 and 9 disposed so as to be opposed to each other. LC) 5 is enclosed.

  The present invention includes TN (Twisted Nematic), STN (Super Twisted Nematic), IPS (In-Plane Switching), VA (Vertical Alignment B), OCB (Optically Compensated B), A liquid crystal of a liquid crystal alignment mode such as a method can be applied.

  A TFT (thin film transistor) array 10 is formed on the inner surface of the first transparent substrate 8, and a transparent electrode layer 11 made of, for example, ITO is formed thereon. An alignment layer 12 is provided on the transparent electrode layer 11. A polarizing plate 13 including a retardation film is formed on the outer surface of the transparent substrate 8.

On the other hand, the color filter 14 of the present invention is formed on the inner surface of the second transparent substrate 9. The red, green and blue filter segments constituting the color filter 14 are separated by a black matrix (not shown). A transparent protective film (not shown) is formed so as to cover the color filter 14 and further, a transparent electrode layer 15 made of, for example, ITO is formed thereon, and the alignment layer 16 is covered so as to cover the transparent electrode layer 15. Is provided. A polarizing plate 17 is formed on the outer surface of the transparent substrate 9. A backlight unit 19 having a three-wavelength lamp 18 is provided below the polarizing plate 13.

  Examples of the present invention and comparative examples will be described below. In addition, this invention is not limited to this in the range which does not deviate from the meaning of this invention. In addition, since the material used in the present invention is extremely sensitive to light, it is necessary to prevent exposure to unnecessary light such as natural light, and it goes without saying that the following operations are performed under a yellow or red light.

<Example 1>
The coloring composition used for color filter preparation was prepared in the following way.
(Production of red pigment dispersion)
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 red pigment dispersion.
-Red pigment: C.I. I. Pigment Red 254 19.5 parts by mass (“Ilgar Four Red B-CF” manufactured by Ciba Specialty Chemicals)
-Red pigment: C.I. I. Pigment Red 177 2.0 parts by mass (“Chromophthal Red A2B” manufactured by Ciba Specialty Chemicals)
・ 2.0 parts by weight of dispersant (“Ajisper PB821” manufactured by Ajinomoto Fine Techno Co., Ltd.)
Acrylic varnish (solid content 20%) 76.5 parts by mass [Preparation of red coloring composition 1]
Thereafter, a mixture having the following composition was stirred and mixed so as to be uniform, and then filtered through a 5 μm filter to obtain a red colored composition 1.
-Red pigment dispersion 48.0 parts-Photopolymerizable monomer 17.5 parts-Acrylic resin 12.5 parts-Photopolymerization initiator 2.8 parts by weight ("Irgacure-369" manufactured by Ciba Geigy) )
・ Photosensitizer 0.2 parts by mass (“EAB-F” manufactured by Hodogaya Chemical Co., Ltd.)
Cyclohexanone 19.0 parts by mass <Examples 2 to 5 and Comparative Examples 1 to 3>
Red colored compositions 2 to 8 were obtained in the same manner as in Example 1 except that the content ratio of each red colored composition was changed to the content ratio shown in Table 1.

表１に示した各赤色着色祖生物（感光性着色組成物）について、耐溶剤性、純水接触角及び密着性を以下のようにして評価した。

About each red coloring progeny (photosensitive coloring composition) shown in Table 1, solvent resistance, a pure water contact angle, and adhesiveness were evaluated as follows.

(Solvent resistance evaluation)
Red coloring compositions 1 to 8 were each applied on a glass substrate by spin coating, and prebaked at 70 ° C. for 15 minutes to form a coating film having a thickness of 2.3 μm. Next, ultraviolet exposure was performed through a photomask having a stripe pattern with a line width of 20 μm by a proximity exposure method using ultraviolet rays as an exposure light source.

Next, it was washed with water after shower development using a 1.25% by mass sodium carbonate solution. The development time was set to an appropriate time for washing away the unexposed coating film. Next, 230
The substrate for heat resistance evaluation of Examples 1-5 and Comparative Examples 1-3 was produced by heat-processing at 60 degreeC for 60 minutes. Then, it was immersed in 50 degreeC diethylene glycol dimethyl ether for 2 minutes, and the film thickness before and behind that was measured. From the obtained film thickness, the swelling ratio was calculated from the following formula 1, and the case where the swelling ratio was less than 102% was evaluated as ◯, and the case where it exceeded 102% was evaluated as ×. The results are shown in Table 2. (Formula 1) Swelling rate (%) = film thickness after immersion (μm) / film thickness before immersion (μm) × 100
(Evaluation of pure water contact angle)
Red coloring compositions 1 to 8 were each applied on a glass substrate by spin coating, and prebaked at 70 ° C. for 15 minutes to form a coating film having a thickness of 2.3 μm. Next, the entire surface was exposed to ultraviolet rays by a proximity exposure method using ultraviolet rays as an exposure light source.

  Next, it was washed with water after shower development using a 1.25% by mass sodium carbonate solution. The development time was set to an appropriate time for washing away the unexposed coating film. Next, the substrate was subjected to heat treatment at 230 ° C. for 60 minutes to produce pure water contact angle evaluation substrates of Examples 1 to 5 and Comparative Examples 1 to 3. Next, the pure water contact angle of the prepared evaluation substrate at room temperature was measured with a contact angle measuring device CA-VE manufactured by Kyowa Interface Science Co., Ltd. The measurement was performed by a sessile drop method defined in 6 of JIS R3257. As the evaluation criteria, a case where it is 75 degrees or more and 100 degrees or less is indicated by ◯, and a case where it is less than 75 degrees is indicated by x. The results are shown in Table 2.

(Adhesion evaluation)
The adhesion between the overcoat material and the colored film formed from each red coloring composition shown in Table 1 was evaluated as follows. First, the coating films of each of the red colored compositions of Examples 1 to 5 and Comparative Examples 1 to 3 prepared in the same manner as in the pure water contact angle evaluation were washed with ultraviolet rays at an exposure amount of 1000 mJ. Next, a commercially available thermosetting overcoat material JSS-727-S2 manufactured by JSR Corporation is applied by a spin coating method, prebaked at 90 ° C. for 5 minutes, and a film thickness of 1.8 μm is applied. After the film was formed, a heat treatment was performed at 240 ° C. for 30 minutes to produce substrates for evaluating adhesion of Examples 1 to 5 and Comparative Examples 1 to 3.

  The adhesion evaluation was performed by a method called a cross cut peel test (JIS-5400). The surface of each evaluation substrate was cut with 1 mm intervals in a grid pattern with a cutter knife, and the commercially available cellophane tape attached without gaps was peeled off, and then observed with an optical microscope. As the evaluation criteria, a case where there was no peeling of the overcoat layer was marked with ◯, and a case where even a slight peeling was seen was marked with x. The results are shown in Table 2.

＜比較結果＞
表２に示した結果より、本発明の感光性着色組成物を使用した実施例１〜５においては、光及び／又は熱による硬化が促進されることで耐溶剤性が向上し、且つ、オーバーコート層との親和性のバランスが適性となり、オーバーコート層との密着性が良好となる結果となった。それに比較して比較例１〜３では、いずれも密着性が不十分となる結果であった。

<Comparison result>
From the results shown in Table 2, in Examples 1 to 5 using the photosensitive coloring composition of the present invention, the solvent resistance is improved by curing by light and / or heat, and over The balance of the affinity with the coat layer became appropriate, and the adhesion with the overcoat layer was improved. Compared with it, in Comparative Examples 1-3, all were the results in which adhesiveness became inadequate.

  In the above-described adhesion evaluation, instead of the material of the overcoat layer, a photosensitive resin material that is a material of the spacer is applied, and the adhesion with the coating film of the photosensitive coloring composition of the example of the present invention is applied. In this case, good adhesion was shown.

  Since the color filter obtained from the above-described embodiment is excellent in adhesion with the overcoat layer for relaxing the step (horn step) with the pixel center portion that occurs when the pixel ends overlap each other, A liquid crystal display device free from light leakage caused by liquid crystal alignment disorder can be provided.

[Production of liquid crystal display devices]
A transparent electrode layer made of ITO was formed on the color filter obtained in the example described above, and a polyimide alignment layer was further formed thereon. A polarizing plate was formed on the other surface of this glass substrate. On the other hand, a TFT array and pixel electrodes were formed on the surface of a separately prepared (second) glass substrate to obtain a TFT substrate. The prepared color filter and the TFT substrate face each other so that the electrode layers face each other, and are aligned while maintaining a constant distance between the two substrates via a columnar spacer made of transparent resin, and an opening for injecting a liquid crystal composition The periphery was sealed with a sealant so as to leave Next, a liquid crystal composition was injected from the opening, and the opening was sealed to obtain a liquid crystal cell. Further, a polarizing plate was attached to both sides of the liquid crystal cell to obtain a liquid crystal panel. This liquid crystal panel was combined with a backlight unit to obtain a liquid crystal display device. Heating, cooling, pressurization, and decompression were carried out in a series of processes, but there was no defect due to poor adhesion between the colored layer and the overcoat layer as well as light leakage due to horn steps, and any liquid crystal display device Also showed good display quality.

  As described above, by using the photosensitive coloring composition of the present invention, a color filter having high adhesion to the overcoat layer can be obtained, and a liquid crystal display device having high display quality can be obtained.

1 is a schematic cross-sectional view of an embodiment of a color filter of the present invention. 1 is a schematic cross-sectional view of an example liquid crystal display device including a color filter of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Substrate (glass substrate) 2 ... Black matrix 3 ... Colored layer (colored pixel) 4 ... Spacer 5 ... Liquid crystal 6 ... Overcoat layer 7 ... Liquid crystal display device 8 , 9 ... Transparent substrate 10 ... TFT array 11, 15 ... Transparent electrode 12, 16 ... Alignment layer 13, 17 ... Polarizing plate 14 ... Color filter 18 ... Three-wavelength lamp 19 ... Backlight unit

Claims (5)

(B) For a color filter comprising a photopolymerizable monomer, (b) a non-photosensitive resin and / or a photosensitive resin, (c) a photopolymerization initiator, (d) a colorant, and (e) a solvent. In the photosensitive coloring composition,
(B) The content mass ratio (monomer / resin) of the photopolymerizable monomer and (b) the non-photosensitive resin and / or the photosensitive resin is 0.75 or more and 2.0 or less. A photosensitive coloring composition for a color filter.   (D) The photosensitive coloring composition for color filters according to claim 1, wherein the colorant is a red pigment. In a color filter configured to have at least a black matrix and a plurality of colored pixels on a transparent substrate,
A color filter, wherein a contact angle of a colored pixel formed from the photosensitive coloring composition for a color filter according to claim 1 or 2 is 75 degrees or more and 100 degrees or less.
Here, the contact angle is a contact angle at room temperature with respect to pure water, which is determined by a sessile drop method defined in 6 of JIS R3257.   4. The color filter according to claim 3, wherein one color of the plurality of colored pixels is a red pixel.    A liquid crystal display device comprising the color filter according to claim 3.

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