JP2006208580A - Color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color filter free from disturbance in the alignment of a liquid crystal or shift in a switching threshold caused by singular electric characteristics of a liquid crystal display device of a lateral electric field system, that is, a color filter giving no adverse influence on display performance, even when an overcoat layer is not formed on a filter segment. <P>SOLUTION: The color filter comprises at least one red filter segment, at least one blue filter segment and at least one green filter segment, wherein at least one green filter segment is made of a green color composition which contains a pigment carrier comprising a transparent resin or its precursor or a mixture of them, and a halogenated phthalocyanine-based pigment treated with a higher fatty acid, preferably oleic acid. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a color filter for a liquid crystal display device. More specifically, the present invention relates to a color filter in which the electrical properties of the filter segment constituting the color filter do not adversely affect the switching performance of the liquid crystal without providing an overcoat layer on the filter segment.

Liquid crystal display devices are rapidly spreading mainly in computer terminal display devices and television image display devices. The color filter is an important component indispensable for color display of a liquid crystal display device. In recent years, this liquid crystal display device has a high demand for high image quality, and various new types of liquid crystal display devices having a high viewing angle and high-speed response have appeared.
Among these, the horizontal electric field method (In Plane Switching = IPS method) is a method that is widely used because it has excellent display quality such as viewing angle and contrast ratio.

However, the liquid crystal used in the IPS liquid crystal display device has excellent characteristics such as being capable of being driven at a low voltage, but it is electrically connected to members such as a color filter that are inherent in the liquid crystal display device. There is a problem that the performance tends to deteriorate due to the characteristics. Actually, in a liquid crystal display device using a conventional color filter, various display defects have occurred due to liquid crystal orientation disorder and switching threshold deviation caused by unique electrical characteristics of the color filter. The unique electrical characteristics of this color filter are mainly due to the nature of the pigment contained in the filter segment. In conventional color filters, an overcoat layer made of a transparent resin was provided on the filter segment to control the electrical characteristics. . However, since the process for forming the overcoat layer requires equipment and time, it is necessary to put a cost on the color filter, resulting in a disadvantage that the price of the liquid crystal display device increases. Further, when the resistance of the overcoat layer itself is taken into consideration, it is considered preferable that there is no overcoat layer.
JP 2004-117537 A

  The present invention eliminates the liquid crystal alignment disorder and the switching threshold shift caused by the specific electrical characteristics in the horizontal electric field type liquid crystal display device without providing the overcoat layer on the filter segment, that is, the display performance. It is an object to provide a color filter that does not adversely affect the color filter.

The color filter of the present invention includes at least one red filter segment, at least one blue filter segment, and at least one green filter segment, and the at least one green filter segment is a transparent resin, a precursor thereof, or their It is formed from a green coloring composition containing a pigment carrier comprising a mixture and a halogenated phthalocyanine pigment treated with a higher fatty acid.
In the color filter of the present invention, the higher fatty acid used for the treatment of the halogenated phthalocyanine pigment is preferably oleic acid. Moreover, it is preferable that content of the halogenated phthalocyanine-type processed pigment processed with the higher fatty acid in 100 weight part of non volatile matters of a green coloring composition is 30-70 weight part.

  Since the halogenated phthalocyanine pigment contained in the color filter of the present invention is treated with a higher fatty acid, the color filter of the present invention does not release halogen ions that adversely affect the electrical characteristics. For this reason, the color filter of the present invention does not have an overcoat layer on the filter segment, and the liquid crystal display device of the horizontal electric field type has a liquid crystal orientation disorder caused by unique electrical characteristics and a switching threshold shift. And does not adversely affect display performance.

Below, the color filter of this invention is demonstrated in detail based on the embodiment.
The color filter of the present invention includes at least one red filter segment, at least one blue filter segment, and at least one green filter segment, and the at least one green filter segment is a transparent resin, a precursor thereof, or their It is formed from a green coloring composition containing a pigment carrier made of a mixture and a halogenated phthalocyanine pigment treated with a higher fatty acid (hereinafter referred to as “treated pigment”).

First, the green coloring composition used for formation of a green filter segment is demonstrated.
The green colored composition contains a pigment carrier and a treated pigment, and the treated pigment is preferably 30 to 70 in 100 parts by weight of the non-volatile content of the green colored composition (components other than the solvent contained in the green colored composition). It is contained in the green coloring composition in an amount of parts by weight, more preferably 40 to 55 parts by weight.
The treated pigment is obtained by kneading a halogenated phthalocyanine pigment together with a higher fatty acid and coating the surface of the halogenated phthalocyanine pigment with the higher fatty acid. Higher fatty acids are not adsorbed on the surface of the halogenated phthalocyanine pigment and are not coated on the surface of the halogenated phthalocyanine pigment simply by mixing with the halogenated phthalocyanine pigment. The improvement effect of the electrical property is exhibited only after kneading with the halogenated phthalocyanine pigment and coating the surface of the halogenated phthalocyanine pigment with a higher fatty acid without exhibiting the improvement effect of the electrical property which causes it.

［式中、Ｘ₁〜Ｘ₁₆は、それぞれ独立に、Ｈ、Ｆ、Ｃｌ、Ｂｒ、またはＩを表し、少なくとも１つはハロゲン元素である。Ｚ（中心金属）は、元素周期表の第４族〜第１４族の元素を表す。］ The halogenated phthalocyanine pigment is a pigment represented by the following general formula (1), and examples thereof include CI Pigment Green 7, 36, and 37.

[Wherein, X _{1 to} X ₁₆ each independently represent H, F, Cl, Br, or I, and at least one is a halogen element. Z (central metal) represents an element of Group 4 to Group 14 of the periodic table. ]

Examples of the central metal Z of the halogenated phthalocyanine pigment include Cu, Al, Co, Ni, Ti, and Zn.
As the halogenated phthalocyanine pigment, for example, crude phthalocyanine blue is halogenated by a known method and then refined (pigmented) to an appropriate particle size (0.05 to 0.5 μm). Can do.
Although the central metal of crude phthalocyanine blue is copper, halogenation of crude phthalocyanine other than copper as the central metal can also be performed using the same method as for crude phthalocyanine blue.

As the higher fatty acid, a linear (non-branched) monovalent carboxylic acid having a large molecular weight is preferable, and either an unsaturated higher fatty acid or a saturated higher fatty acid can be used. Examples of unsaturated higher fatty acids include oleic acid, linoleic acid, linolenic acid, and the like. Examples of saturated fatty acids include palmitic acid and stearic acid. Among these, oleic acid is preferably used because it has good compatibility with the pigment carrier. The higher fatty acids can be used alone or in admixture of two or more.
The amount of treatment with the higher fatty acid is preferably 2 to 15 parts by weight, more preferably 3 to 10 parts by weight with respect to 100 parts by weight of the halogenated phthalocyanine pigment. When the amount of treatment with the higher fatty acid is less than 2 parts by weight, a sufficient effect of improving electrical characteristics is not recognized. Moreover, when more than 15 weight part, coating-film adhesiveness worsens.

  The higher fatty acid treatment of the halogenated phthalocyanine pigment can be carried out by kneading a mixture of the halogenated phthalocyanine pigment and the higher fatty acid by a method such as salt milling or dry milling. By kneading the mixture of the halogenated phthalocyanine pigment and the higher fatty acid, most of the higher fatty acid is adsorbed on the surface of the halogenated phthalocyanine pigment.

  Specifically, the salt milling treatment is performed by kneading a mixture of a halogenated phthalocyanine pigment, a higher fatty acid, a water-soluble inorganic salt, and a water-soluble organic solvent using a kneader such as a kneader, followed by washing with water. Is a treatment for removing the water-soluble inorganic salt and the water-soluble organic solvent. The water-soluble inorganic salt works as a crushing aid, and the pigment is sized using the high hardness of the inorganic salt during the salt milling process. Adsorb higher fatty acids. When the pigment is subjected to a salt milling treatment, the heating temperature is preferably 70 to 150 ° C., since the coating efficiency is improved by promoting the sizing of the pigment by heating. When the heating temperature deviates from 70 to 150 ° C., it is not preferable because the sizing efficiency of the pigment is poor, that is, it takes too much time to coat the pigment surface with higher fatty acids.

As the water-soluble inorganic salt, sodium chloride, barium chloride, potassium chloride, sodium sulfate and the like can be used, but sodium chloride (salt) is preferably used from the viewpoint of cost. The amount of the inorganic salt used in the salt milling treatment is 0.5 to 20 times by weight, particularly 1 to 10 times by weight of the pigment, in terms of the treatment efficiency, that is, the coating efficiency of the pigment surface with higher fatty acids and the production efficiency. It is preferable.
The water-soluble organic solvent functions to wet the pigment and the water-soluble inorganic salt, and is not particularly limited as long as it dissolves (mixes) in water and does not substantially dissolve the inorganic salt to be used. However, a high boiling point solvent having a boiling point of 120 ° C. or higher is preferable from the viewpoint of safety because the temperature rises during the salt milling process and the solvent is easily evaporated.

  Examples of the water-soluble organic solvent include 2-methoxyethanol, 2-butoxyethanol, 2- (isopentyloxy) ethanol, 2- (hexyloxy) ethanol, diethylene glycol, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol. , Triethylene glycol monomethyl ether, liquid polyethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, liquid polypropylene glycol, etc. Is used.

  The dry milling process is a process of dry pulverizing a halogenated phthalocyanine pigment and a higher fatty acid using a dry grinding apparatus incorporating a grinding media such as beads, for example, a ball mill, an attritor, a vibration mill, or the like. . The pigment is sized through collision and friction between the pulverizing media, and a higher fatty acid is adsorbed on the pigment surface using the cohesive energy of the pigment generated during the sizing. The dry milling process may be performed by depressurizing the inside of the pulverizer or filling an inert gas such as nitrogen gas as necessary. Although there is no restriction | limiting in particular about the operating conditions of a dry-type grinding | pulverization apparatus, In order to advance coating | cover of the pigment surface by a higher fatty acid effectively, the following conditions are especially preferable.

When the dry pulverization apparatus is an attritor, the rotation speed of the apparatus is preferably 100 to 500 rpm, the dry pulverization time is preferably 0.5 to 8 hours, and the internal temperature of the apparatus is preferably 50 to 150 ° C. The grinding media is preferably spherical with a diameter of 4 to 30 mm, and the amount of media used is preferably 5 to 50 times the weight of the pigment to be treated.
When the dry pulverization apparatus is a ball mill, the rotation speed of the apparatus is preferably 50 to 200 rpm, the dry pulverization time is preferably 1 to 12 hours, and the internal temperature of the apparatus is preferably 30 to 100 ° C. The grinding media is preferably spherical with a diameter of 10 to 50 mm, and the amount of media used is preferably 5 to 50 times the weight of the pigment to be treated.

  In order to obtain the desired spectral characteristics, the green coloring composition contains 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, 185, 187, 188, 193, 194, 198, 199, 213, 214, 217, and the like.

The pigment carrier is for dispersing the treated pigment, and, as described above, is composed of a transparent resin, a precursor thereof, or a mixture thereof. The transparent resin is a resin having a transmittance of preferably 80% or more, more preferably 95% or more in the entire wavelength region of 400 to 700 nm in the visible light region. Examples of the transparent resin include a thermoplastic resin, a thermosetting resin, and a photosensitive resin. Examples of the precursor include a monomer or an oligomer that is cured by radiation irradiation to form a transparent resin. A mixture of more than one species can be used.
The pigment carrier can be used in an amount of 25 to 300 parts by weight, preferably 50 to 200 parts by weight, based on 100 parts by weight of the halogenated phthalocyanine pigment in the treated pigment.

  Examples of thermoplastic resins 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, styrene resins, polyamide resins, rubber resins, cyclized rubber resins, celluloses, polybutadiene, polyimide resins, and the like. Moreover, as a thermosetting resin, an epoxy resin, a benzoguanamine resin, a melamine resin, a urea resin, a phenol resin etc. are mentioned, for example.

  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 in which a photocrosslinkable group such as a (meth) acryloyl group or a styryl group is introduced by reacting cinnamic acid 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.

  Monomers and oligomers that are precursors of transparent resins include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, cyclohexyl (meth) acrylate, polyethylene glycol di (meth) acrylate, pentaerythritol tri (meth) ) Acrylate, dipentaerythritol hexa (meth) acrylate, tricyclodecanyl (meth) acrylate, melamine (meth) acrylate, epoxy (meth) acrylate, and other acrylic and methacrylic esters, (meth) acrylic acid, styrene , Vinyl acetate, (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, acrylonitrile and the like.

When the composition is cured by irradiation with light such as ultraviolet rays, a photopolymerization initiator or the like is added to the green coloring composition.
As photopolymerization initiators, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1-hydroxy Acetophenone photopolymerization initiators such as cyclohexyl phenyl ketone and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether Benzoin photopolymerization initiators such as benzyldimethyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-ben Benzophenone photopolymerization initiators such as yl-4'-methyldiphenyl sulfide, thioxanthone light such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone Polymerization initiator, 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxyphenyl) -4,6-bis (trichloro) Methyl) -s-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2-piperonyl-4,6-bis (trichloromethyl) -s-triazine, 2,4 -Bis (trichloromethyl) -6-styryl-s-triazine, 2- (naphth-1-yl) -4,6-bis (to Chloromethyl) -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 and other triazine photopolymerization initiators, borate photopolymerization initiators, carbazole photopolymerization initiators, imidazole photopolymerization initiators and the like are used. It is done.
The photopolymerization initiator can be used in an amount of 1 to 100 parts by weight, preferably 10 to 50 parts by weight, based on 100 parts by weight of the halogenated phthalocyanine pigment in the treated pigment.

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, ethylanthraquinone, 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 used in an amount of 0.1 to 30 parts by weight with respect to 100 parts by weight of the photopolymerization initiator.

In the green coloring composition, the treated pigment is finely dispersed in the pigment carrier together with the photopolymerization initiator as necessary using various dispersing means such as a three-roll mill, a two-roll mill, a sand mill, and a kneader. Can be manufactured.
When the treated pigment is dispersed in the pigment carrier, a dispersion aid such as a resin-type dispersant, a surfactant, and a dye derivative can be appropriately contained. Since the dispersion aid is excellent in dispersion of the treated pigment and has a large effect of preventing re-aggregation of the treated pigment after dispersion, when the treated pigment is dispersed in the pigment carrier using the dispersion aid, dispersibility, In particular, a colored composition excellent in storage stability and low thixotropy can be obtained. The dispersing aid can be used in an amount of 3 to 20 parts by weight, preferably 5 to 15 parts by weight, based on 100 parts by weight of the halogenated phthalocyanine pigment in the treated pigment.
Among the dispersion aids, a dye derivative having a basic group, or a dye derivative having an acidic group or a salt thereof is preferably used because the dispersion effect of the treated pigment is large.

  Since the resin-type dispersant used in the green coloring composition is adsorbed on the surface of the treated pigment using an acidic group or a basic group as an anchor, the repulsive effect of the polymer acts effectively and expresses dispersion stability retention. A polymer having an acidic group or a basic group is preferred. The acidic group is preferably a sulfone group from the viewpoint of excellent adsorption characteristics, and the basic group is preferably an amino group from the viewpoint of excellent adsorption characteristics. In addition, combined use of a derivative having an acidic group and a resin-type dispersant having a basic group, or a combination of a derivative having a basic group and a resin-type dispersant having an acidic group is compatible with the pigment carrier. preferable.

As a resin type dispersant having an acidic group or a basic group, a comb polymer having a structure in which a branch polymer part is graft-bonded to a trunk polymer part having an acidic group or a basic group has an excellent steric repulsion effect of the branch polymer part. It is preferable because it is more soluble in organic solvents. Furthermore, a comb polymer having a molecular structure in which two or more branch polymers are grafted to one molecule of the trunk polymer is more preferable for the above reason.
Specific examples of the trunk polymer constituting the basic resin type dispersant include polyethyleneimine, polyethylene polyamine, polyxylylene poly (hydroxypropylene) polyamine, poly (aminomethylated) epoxy resin, amine-added glycidyl (meth) acrylate Examples include (meth) acrylic esterified glycidyl (meth) acrylate copolymers. These synthesis methods are as follows, for example.

Polyethyleneimine is obtained by ring-opening polymerization of ethyleneimine in the presence of an acid catalyst.
Polyethylene polyamine can be obtained by polycondensation of ethylene dichloride and ammonia in the presence of an alkali catalyst.
Poly (aminomethylated) epoxy resin aminates aromatic rings such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, naphthol novolak type epoxy resin after chloromethylation And is also called Mannich base. Specific examples of the amine used in the amination include monomethylamine, monoethylamine, monomethanolamine, monoethanolamine, dimethylamine, diethylamine, dimethanolamine, diethanolamine and the like.

  The amine-added glycidyl (meth) acrylate- (meth) acrylic esterified glycidyl (meth) acrylate copolymer is polymerized by radical polymerization of glycidyl (meth) acrylate, and then a part of the epoxy group in the polymer. An amine similar to that exemplified above is added to obtain poly [amine-added glycidyl (meth) acrylate], and then the remaining epoxy group is obtained by esterification with a carboxylic acid of (meth) acrylic acid.

  The branched polymer is preferably an organic solvent-soluble polymer. Specific examples thereof include a polymer having a carboxylic acid at the polymer terminal and capable of forming a graft bond by amidation with the amino group of the trunk polymer as described above. And ring-opening polymers such as poly (12-hydroxystearic acid), polyricinoleic acid, and ε-caprolactone. Further, when the backbone polymer has a vinyl group such as the above-mentioned amine-added glycidyl (meth) acrylate- (meth) acrylate esterified glycidyl (meth) acrylate copolymer, a polypolymer that can be graft-polymerized to the vinyl group. [Methyl (meth) acrylate], poly [(meth) ethyl acrylate] and the like can be listed as the branch polymer. These synthesis methods are as follows, for example.

Poly (12-hydroxystearic acid) is obtained by a dehydration polycondensation polyesterification reaction of 12-hydroxystearic acid.
Polyricinoleic acid is similarly obtained by a dehydration polycondensation polyesterification reaction of ricinoleic acid.
A ring-opening polymer of ε-caprolactone is obtained by adding n-caproic acid, which is an aliphatic monocarboxylic acid, to ε-caprolactone to initiate ring-opening polymerization.

  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.

  A dye derivative is a compound in which a basic or acidic substituent is introduced into an organic dye. Organic dyes include light yellow aromatic polycyclic compounds that are not generally called dyes, such as naphthalene, anthraquinone, and acridone. Examples of the dye derivative include JP-A-63-305173, JP-B-57-15620, JP-B-59-40172, JP-B-63-17102, JP-B-5-9469, JP-A-9- 176511 gazette etc. can be used, and these can be used individually or in mixture of 2 or more types.

In the green coloring composition, the treated pigment is sufficiently dispersed in the pigment carrier, and it is easy to form by coating on a transparent substrate such as a glass substrate so that the dry film thickness is 0.2 to 5 μm. Therefore, a solvent can be contained. Examples of the solvent include cyclohexanone, ethyl cellosolve acetate, butyl cellosolve acetate, 1-methoxy-2-propyl acetate, diethylene glycol dimethyl ether, ethylbenzene, ethylene glycol diethyl ether, xylene, ethyl cellosolve, methyl-n amyl ketone, propylene glycol monomethyl ether toluene, methyl ethyl ketone. , Ethyl acetate, methanol, ethanol, isopropyl alcohol, butanol, isobutyl ketone, petroleum solvent and the like, and these are used alone or in combination.
The solvent can be used in an amount of 400 to 5000 parts by weight, preferably 500 to 2000 parts by weight with respect to 100 parts by weight of the halogenated phthalocyanine pigment in the treated pigment.

Next, a method for manufacturing the color filter of the present invention will be described.
The color filter of the present invention is produced by forming filter segments of each color on a substrate using a red, green, and blue coloring composition by a known inkjet method, printing method, photoresist method, etching method, or the like. be able to. In particular, considering high definition, controllability and reproducibility of spectral characteristics, each color coloring composition (colored resist material) in which a pigment is dispersed in a composition containing a transparent resin, a monomer, and a photopolymerization initiator Preferably, a photoresist method is used in which a color filter is produced by repeating the process of forming a single color filter segment by pattern exposure and development after coating a film on a substrate.

As the substrate, a glass plate having a high transmittance with respect to visible light, or a resin plate such as polycarbonate, polymethyl methacrylate, or polyethylene terephthalate is used. A pattern made of a light shielding resin may be formed on the substrate in advance.
For the formation of the red filter segment and the blue filter segment, a red coloring composition prepared by using the following red pigment or blue pigment instead of the higher fatty acid halogenated phthalocyanine pigment of the green coloring composition described above. And blue colored compositions are used.

Examples of the red coloring composition include C.I. I. Pigment Red 7, 14, 41, 48: 1, 48: 2, 48: 3, 48: 4, 81: 1, 81: 2, 81: 3, 81: 4, 146, 168, 177, 178, 184, Red pigments such as 185, 187, 200, 202, 208, 210, 246, 254, 255, 264, 270, 272, and 279 are used. The red coloring composition includes C.I. I. An orange pigment such as Pigment Orange 43, 71, 73, or a yellow pigment exemplified in the description of the green coloring composition can be used in combination.
Examples of the blue coloring composition include C.I. I. Blue pigments such as Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 22, 60, and 64 can be used. Blue coloring compositions include C.I. I. Pigment Violet 1, 19, 23, 27, 29, 30, 32, 37, 40, 42, 50, and other purple pigments can be used in combination.

Hereinafter, a method for producing a color filter by a photoresist method will be specifically described.
A colored composition of the first color prepared as a colored resist material is applied on a transparent substrate and prebaked. The coloring composition can be applied by spin coating, dip coating, die coating, or the like, but is not limited to these methods as long as it can be applied on the transparent substrate with a uniform film thickness. Prebaking is preferably performed at 50 to 120 ° C. for about 10 to 20 minutes. The coating film thickness is arbitrary, but considering the spectral transmittance and the like, the film thickness after pre-baking is usually about 2 μm. The transparent substrate coated with the coloring composition is exposed through a pattern mask. A normal high-pressure mercury lamp or the like may be used as the light source.

Subsequently, development is performed. As the developer, an alkaline aqueous solution is preferably used. Examples of the alkaline aqueous solution include a sodium carbonate aqueous solution, a sodium hydrogen carbonate aqueous solution, a mixed aqueous solution of the two, or a mixture obtained by adding an appropriate surfactant to them. After the development, the filter segment of the first color is obtained by washing with water and drying.
By repeating the above-described series of steps by changing the pattern using the remaining two-color coloring composition, at least one red filter segment, at least one blue filter segment, and at least one green filter segment are provided. A color filter can be obtained.

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”.
First, resin solutions and treated pigments used in Examples and Comparative Examples will be described.

(Preparation of acrylic resin solution)
A reaction vessel equipped with a separable four-necked flask equipped with a thermometer, a cooling tube, a nitrogen gas introduction tube, and a stirrer was charged with 70.0 parts of cyclohexanone, heated to 80 ° C., and the inside of the reaction vessel was purged with nitrogen. 13.3 parts of n-butyl methacrylate, 4.6 parts of 2-hydroxyethyl methacrylate, 4.3 parts of methacrylic acid, 7.4 parts of paracumylphenol ethylene oxide modified acrylate (“Aronix M110” manufactured by Toagosei Co., Ltd.), A mixture of 0.4 part of 2,2′-azobisisobutyronitrile was added dropwise over 2 hours. After completion of the dropping, the reaction was further continued for 3 hours to obtain an acrylic resin solution which was a transparent resin having a weight average molecular weight of 26000. After cooling to room temperature, about 2 g of the resin solution is sampled and heated and dried at 180 ° C. for 20 minutes to measure the non-volatile content, and then dried under reduced pressure so that the non-volatile content becomes 20% by weight in the previously synthesized resin solution, or Cyclohexanone was added to prepare an acrylic resin solution serving as a pigment carrier.

(Preparation of phthalocyanine-based green-treated pigment 1)
As a halogenated phthalocyanine pigment, 500 parts of CI Pigment Green 36 (“Lionol Green 6YK” manufactured by Toyo Ink Mfg. Co., Ltd.), 500 parts of sodium chloride, 250 parts of diethylene glycol, and 50 parts of oleic acid, 1 gallon kneader made of stainless steel (manufactured by Inoue Seisakusho) And kneaded at 120 ° C. for 2 hours. Next, the kneaded product is poured into 5 liters of warm water, stirred for 1 hour while heating to 70 ° C. to form a slurry, filtered and washed repeatedly to remove sodium chloride and diethylene glycol, and then dried at 80 ° C. overnight. As a result, a phthalocyanine-based green-treated pigment 1 was obtained.

(Preparation of Phthalocyanine Green Treatment Pigment 2)
A phthalocyanine-based green-treated pigment 2 was obtained in the same manner as the phthalocyanine-based green-treated pigment 1 except that the amount of oleic acid used was changed from 50 parts to 15 parts.
(Preparation of phthalocyanine-based green-treated pigment 3)
A phthalocyanine green treated pigment 3 was obtained in the same manner as the phthalocyanine green treated pigment 1 except that the amount of oleic acid used was changed from 50 parts to 75 parts.
(Preparation of phthalocyanine-based green-treated pigment 4)
A phthalocyanine-based green-treated pigment 4 was obtained in the same manner as the phthalocyanine-based green-treated pigment 1 except that the amount of oleic acid used was changed from 50 parts to 5 parts.
(Preparation of phthalocyanine-based green-treated pigment 5)
A phthalocyanine green treated pigment 5 was obtained in the same manner as the phthalocyanine green treated pigment 1 except that the amount of oleic acid used was changed from 50 parts to 100 parts.

[Example 1]
A mixture having the following composition was uniformly stirred and mixed, and then dispersed with an Eiger mill for 5 hours using zirconia beads having a diameter of 0.5 mm, followed by filtration with a 5 μm filter to prepare a green pigment dispersion.
Phthalocyanine green pigment 1 8.6 parts Azo yellow pigment (“E4GN-GT” manufactured by Bayer) 4.9 parts Dispersant (“Solspers 5000” manufactured by Avicia) 1.5 parts Acrylic resin solution 40.0 parts 7.0 parts of trimethylolpropane triacrylate (“NK ESTER ATMPT” manufactured by Shin-Nakamura Chemical Co., Ltd.)
38.0 parts of cyclohexanone Subsequently, a mixture having the following composition was stirred and mixed so as to be uniform, and then filtered through a 1 μm filter to obtain a green colored composition.
Green pigment dispersion 53.33 parts Acrylic resin solution 7.75 parts Photopolymerization initiator ("Irgacure 907" manufactured by Ciba) 2.24 parts Surfactant ("BYK-323" manufactured by BYK Chemie) 0.03 parts Storage stabilizer (“TPP” manufactured by Hokuko Chemical Co., Ltd.) 0.20 parts Cyclohexanone 36.45 parts

[Example 2]
Phthalocyanine green treated pigment 1: 8.6 parts is changed to phthalocyanine green treated pigment 2: 7.9 parts, the amount of acrylic resin solution used is changed from 40.0 parts to 43.5 parts, and the amount of cyclohexanone used is changed. A pigment dispersion was prepared in the same manner as in Example 1 except that the amount was changed from 38.0 parts to 35.8 parts to obtain a green coloring composition.
[Example 3]
Phthalocyanine green treated pigment 1: 8.6 parts are changed to phthalocyanine green treated pigment 3: 9.11 parts, the amount of acrylic resin solution used is changed from 40.0 parts to 37.45 parts, and the amount of cyclohexanone used is changed. A pigment dispersion was prepared in the same manner as in Example 1 except that the amount was changed from 38.0 parts to 40.04 parts to obtain a green coloring composition.

[Example 4]
Phthalocyanine-based green treated pigment 1: 8.6 parts is changed to phthalocyanine-based green treated pigment 4: 7.82 parts, the amount of acrylic resin solution used is changed from 40.0 parts to 43.9 parts, and the amount of cyclohexanone used is increased. A pigment dispersion was prepared in the same manner as in Example 1 except that the amount was changed from 38.0 parts to 34.88 parts to obtain a green coloring composition.
[Example 5]
Phthalocyanine green treated pigment 1: 8.6 parts are changed to phthalocyanine green treated pigment 5: 9.68 parts, the amount of acrylic resin solution used is changed from 40.0 parts to 34.6 parts, and the amount of cyclohexanone used is changed. A pigment dispersion was prepared in the same manner as in Example 1 except that 38.0 parts was changed to 42.32 parts to obtain a green coloring composition.

[Comparative Example 1]
A green colored composition was obtained in the same manner as in Example 1 except that the phthalocyanine-based green-treated pigment 1 was changed to an untreated CI Pigment Green 36 pigment (“Lionol Green 6YK” manufactured by Toyo Ink Manufacturing Co., Ltd.).

Using the green colored compositions obtained in Examples 1 to 5 and Comparative Example 1, coating films were prepared by the following methods, and adhesion, dielectric loss tangent, and dielectric constant were evaluated. The results are shown in Table 1.
(1) Adhesiveness evaluation of coating film The green coloring composition was applied on a glass substrate having a thickness of 100 mm × 100 mm and a thickness of 1.1 mm using a spin coater at a rotation speed of 2.0 μm and dried under reduced pressure. Cellophane tape peel was performed on the formed coating film. The evaluation criteria are shown below.
◎ ---- No peeling with cellophane tape peel ○ ---- Some peeling with cellophane tape peel (peeling area less than 20%)
△ ---- Conspicuous peeling with cellophane tape peel (20% or more and less than 80% of peeled surface seat)
× ---- With cellophane tape peel, there is overall peeling (80% or more peeling surface seat)

(2) Evaluation of electrical characteristics (dielectric loss tangent, relative permittivity) of coating film 2. Using a spin coater on a 100 mm × 100 mm, 1.1 mm thick glass substrate on which a green coloring composition was vapor-deposited for an electrode. Coating was performed at a rotation speed of 0 μm thickness to obtain a coated substrate. Next, after drying under reduced pressure, ultraviolet exposure was performed using an ultra-high pressure mercury lamp with an integrated light amount of 300 mJ and an illuminance of 30 mW. After alkali development, the coated substrate is heated at 230 ° C. for 1 hour and allowed to cool, and aluminum for an electrode with an area of 3.464 × 10 ⁻⁴ m ² is vapor-deposited on the resulting cured coating film. A sample sandwiched between aluminum electrodes was prepared. The dielectric loss tangent of 10 Hz to 1 MHz of the obtained sample was measured at an applied voltage of 100 mV using an impedance analyzer (“1260 type” manufactured by Solartron), and the dielectric loss tangent and relative dielectric constant were measured.

As shown in the dielectric loss tangent evaluation results of the coating films in Table 1, the coating films formed from the green coloring compositions of Examples 1 to 5 using the treated pigment have low tan δ values of 10 Hz and 50 Hz, and the dielectric loss tangent Is good.
Moreover, as shown to the dielectric constant evaluation result of the coating film of Table 1, the coating film formed from the green coloring composition of Examples 1-5 using a process pigment is a value of the dielectric constant of 10 Hz and 50 Hz. It can be seen that a coating film with good electrical characteristics is formed by using the treated pigment.

Moreover, as shown in the adhesion evaluation results of the coating film in Table 1, Example 3 using more than 10 parts of the treated pigment more than the optimum upper limit of the higher fatty acid treatment amount with respect to 100 parts of the halogenated phthalocyanine pigment. And the coating film formed from the green coloring composition of Example 5 has low adhesiveness of a coating film. In particular, the coating film formed from the green coloring composition of Example 5 using 20 parts of the treated pigment having a higher higher fatty acid treatment amount than the preferred amount with respect to 100 parts of the halogenated phthalocyanine pigment was peeled off from the entire surface. The adhesion of the coating film is so low that it will end up.
In addition, the coating film formed from the green coloring composition of Example 4 using a treated pigment having less than 3 parts of the upper limit of the optimum amount of fatty acid to 100 parts of the halogenated phthalocyanine pigment is a higher fatty acid. Compared with the coating film formed from the green coloring composition of Example 1 and Example 2 which used the processing pigment in which the processing amount was in the range of the optimal amount, the dielectric loss tangent and relative dielectric constant were high and bad.

Next, in order to evaluate the panel reliability of a color filter including a red filter segment, a blue filter segment, and a green filter segment (High temperature High Bias Test), the red coloring composition and the blue coloring composition are subjected to the following method. It was prepared with.
(Red coloring composition)
A mixture having the following composition was stirred and mixed uniformly, then dispersed with an Eiger mill for 3 hours using zirconia beads having a diameter of 1 mm, and then filtered with a 5 μm filter to prepare a red dispersion. A red colored composition was obtained in the same manner as the green colored composition of Example 1 except that the obtained red pigment dispersion was used instead of the green pigment dispersion.
Red pigment (“Irgafore Red BT-CF” manufactured by Ciba) 10.0 parts Acrylic resin solution 50.0 parts Cyclohexanone 40.0 parts

(Blue coloring composition)
A mixture having the following composition was stirred and mixed uniformly, then dispersed with an Eiger mill for 3 hours using zirconia beads having a diameter of 1 mm, and then filtered with a 5 μm filter to prepare a blue dispersion. A blue colored composition was obtained in the same manner as the green colored composition of Example 1 except that the obtained blue pigment dispersion was used instead of the green pigment dispersion.
Blue pigment (“Lionol Blue ES” manufactured by Toyo Ink Manufacturing Co., Ltd.) 9.0 parts Dispersant (“Solspers 5000” manufactured by Avicia) 1.0 part Acrylic resin solution 50.0 parts Cyclohexanone 40.0 parts

The red coloring composition was applied to a glass substrate by spin coating so as to have a chromaticity of x = 0.603 and y = 0.328 with a C light source. After drying, striped pattern exposure was performed with an exposure machine and development was performed with an alkaline developer for 90 seconds to form a striped red filter segment. In addition, as an alkaline developer, sodium carbonate 1.5% sodium hydrogen carbonate 0.5% anionic surfactant ("PERILEX NBL" manufactured by Kao Corporation) 8.0% and water 90% are used. It was.
Next, the green coloring composition obtained in Examples 1 to 5 or Comparative Example 1 was applied with a C light source so as to have a chromaticity of x = 0.277 and y = 0.600. After drying, a striped pattern adjacent to the red filter segment was exposed with an exposure machine to form a striped green filter segment.
Further, a blue coloring composition is applied with a film thickness such that x = 0.136 and y = 0.142 with a C light source, and a red filter segment and a stripe-shaped blue filter adjacent to the green filter segment are applied. A segment was formed.

The shape of each color filter segment was good, and the resolution was also good. Finally, the obtained color filter is heated in an oven at 230 ° C. for 30 minutes to completely react the remaining polymerizable functional groups, and red, green and blue stripe-shaped filter segments are formed on the transparent substrate. An equipped color filter was obtained.
When the liquid crystal display device of each horizontal electric field system was created using the obtained color filter, in the liquid crystal display device using the color filter produced using the green coloring composition of Examples 1-5, a coating film Low dielectric loss tangent and relative dielectric constant of the liquid crystal drive signal causes the rising and falling shapes of the rectangular wave to be less likely to cause drive voltage threshold shifts. A liquid crystal display device was obtained. On the other hand, in the liquid crystal display device using the color filter manufactured using the green coloring composition of Comparative Example 1, the flickering of the pixels is conspicuous and the electric loss is large, so that the electric signal cannot be transmitted well. Therefore, a severe alignment failure was observed.
As shown by the above results, the color filter of the present invention is an excellent color filter having excellent electrical characteristics and particularly low electrical loss, so that there is no liquid crystal orientation disorder and no switching threshold deviation.

Claims (3)

  A pigment carrier comprising at least one red filter segment, at least one blue filter segment, and at least one green filter segment, the at least one green filter segment comprising a transparent resin, a precursor thereof, or a mixture thereof; A color filter comprising a green coloring composition containing a halogenated phthalocyanine pigment treated with a higher fatty acid.   The color filter according to claim 1, wherein the higher fatty acid is oleic acid.   3. The color filter according to claim 1, wherein the content of the phthalocyanine-treated pigment treated with a higher fatty acid in 100 parts by weight of the nonvolatile content of the green coloring composition is 30 to 70 parts by weight.