JP4471913B2 - Pigment dispersion composition for color resist ink - Google Patents

Description

The present invention relates to a novel pigment dispersion composition for color resist ink in which a pigment is finely dispersed.

  Conventionally, as a pigment dispersion composition in which a finely dispersed component is blended in order to improve the dispersion stability of the pigment, for example, a terminal carboxyl group of poly (12-hydroxystearic acid), 3-dimethylaminopropylamine, In contrast to quinacridone, which is one of the organic pigment compounds, which uses a cationic polymer that is an amidation reaction product of quinacridone alone as a finely dispersed component (for example, Patent Document 1), a sulfone that is an acidic derivative thereof A compound in which a compound salt is mixed alone as a finely dispersed component (for example, Patent Document 2) is known.

  In addition, as a color resist ink using a pigment dispersion composition in which a finely dispersed component is blended, for example, an acrylic resin, an ethylcellulose resin, or a maleic acid resin is used as a finely dispersed component (for example, patent literature) 3) etc. are known.

Japanese Patent Publication No.57-25251 Japanese Patent Publication No. 50-4019 Japanese Examined Patent Publication No. 6-95211

  However, it is difficult to say that these conventional pigment dispersion compositions have sufficient degree of fine dispersion and dispersion stability, and color resist inks prepared using these have problems to be solved with respect to fluidity and light transmittance. For example, when applied to an ink for a color filter for liquid crystal display (hereinafter abbreviated as “CF”), uneven coating occurs during spin coating on a glass substrate, and CF due to insufficient light transmittance after pixel formation. The current situation is that it still has drawbacks such as lack of brightness and contrast.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have formulated and dispersed an acidic derivative of an organic pigment and a cationic comb graft polymer as a finely dispersed component in a pigment dispersion composition. A high degree of fine dispersion and dispersion stability are achieved. Therefore, a color resist ink prepared by blending a photosensitive resin composition with the pigment dispersion composition also exhibits excellent light transmission and stable Newtonian fluidity. When this was applied to CF ink, it was found that there was no coating unevenness during spin coating, and pixels with excellent brightness and contrast could be produced after curing and development, and the present invention was completed.

That is, the present invention relates to (1) a pigment dispersion composition comprising an organic pigment, an organic solvent and a finely dispersed component, wherein the finely dispersed component is an acidic derivative of the organic pigment and a cationic functional group having a cationic functional group in the trunk polymer portion. Composed of a comb-shaped graft polymer, the cationic comb-shaped graft polymer is a polymer composed of a trunk polymer portion having an amino group and a branch polymer portion soluble in an organic solvent, and two or more branch polymers are grafted to one molecule of the trunk polymer. A pigment dispersion composition for a color resist ink, wherein the viscosity ratio is 1.51 or less and the average particle size is 94 nm or less ,
(2) The pigment dispersion composition for a color resist ink as described in 1 above, wherein the organic solvent is an ether, ester, ketone, polyhydric alcohol derivative, or nitrogen-containing solvent.

  In the pigment dispersion composition of the present invention, the pigment is finely dispersed well and has excellent light transmittance. For this reason, the color resist ink prepared by blending the photosensitive resin composition with the composition makes it possible to produce a color filter for a liquid crystal display excellent in lightness-chroma and contrast. The pigment dispersion composition of the present invention is also useful as a raw material for inks other than for high gloss paints and highly transparent color filters.

  The first of the finely dispersed components used in the pigment dispersion composition of the present invention is an acidic derivative of an organic pigment. The acidic derivative of the organic pigment can be represented, for example, by the following formula (1).

  Examples of the acidic group represented by X in the formula (1) include a sulfonic acid group and a terephthalic acid monoamidomethyl group. Sulfonic acid groups can be introduced by allowing sulfuric acid to act on organic pigments, and terephthalic acid monoamidomethyl groups can be chloromethylated and then aminomethylated with primary amines and then monoamidated with terephthalic acid. Can be introduced.

  The organic pigment compound that is the base of the acidic derivative of the organic pigment is not particularly limited as long as the acidic derivative can be obtained. For example, in red / orange systems, anthraquinonyl red, anthanthrone red, tetrachlorothioindigo, perylene red, perylene slow red, perylene maroon, quinacridone red, quinacridone magenta, diketopyrrolopyrrole red BO Permanent Red R, Dinitroaniline Orange, Brilliant Carmine FB, Permanent Red F5RK, Pyrazolone Orange, Pyrazolone Red, Permanent Red 2B, Lake Red R, Bordeaux 10B, Bon Maroon Medium, Bon Maroon belonging to Soluble Azo Light etc. are mentioned. In the yellow series, the first yellow G belonging to the monoazo series, the benzimidazolone yellow HG, the permanent yellow belonging to the disazo series, the anthrapyrimidine yellow belonging to the slen series, the flavantron yellow, the azomethine series copper complex yellow belonging to the metal complex series, the nitroso nickel Examples thereof include complex yellow, nickel azo yellow, and quinophthalone yellow belonging to the quinophthalone series. Examples of the green type include chlorinated phthalocyanine green and odor chlorinated phthalocyanine green. Examples of the blue type include phthalocyanine blue, copper phthalocyanine blue, and indanthrene blue. In the purple type, dioxazine violet, quinacridone violet and the like can be mentioned.

  The second of the finely dispersed components used in the pigment dispersion composition of the present invention is a comb-shaped graft polymer having a cationic functional group in the trunk polymer portion. The cationic comb graft polymer is a polymer having a structure in which a branch polymer portion is graft-bonded to a trunk polymer portion having a plurality of basic groups, and the surface of the organic pigment and its acidic derivative using the basic group of the trunk polymer portion as an anchor. Therefore, the steric repulsion effect of the branched polymer part acts effectively, and the function of promoting fine dispersion is developed. The basic group of the trunk polymer part is preferably an amino group from the viewpoint of excellent adsorption characteristics, and the branched polymer part is preferably organic solvent-soluble from the viewpoint of excellent steric repulsion effect. Further, it preferably has a molecular structure in which two or more branch polymers are grafted to one molecule of the trunk polymer. Such a cationic comb-shaped graft polymer can be represented, for example, by the following formula (2).

  In the formula (2), the backbone polymer represented by AA ... AA is preferably one having an amino group. Specific examples thereof include polyethyleneimine, polyethylenepolyamine, polyxylylenepoly (hydroxypropylene) polyamine, polyamine. (Aminomethylated) epoxy resin, amine-added glycidyl (meth) acrylate- (meth) acrylic acid esterified glycidyl (meth) acrylate copolymer, and the like. 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 resins are chlormethylated and aminated after aromatic rings such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolak type epoxy resin, naphthol novolak type epoxy resin, etc. 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 described 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.

  In the formula (2), the branched polymer represented by BB ... BB is preferably an organic solvent-soluble polymer. Specific examples thereof include a carboxylic acid at the polymer terminal, and the amino group in the trunk polymer as described above. Examples thereof include ring-opening polymers such as poly (12-hydroxystearic acid), polyricinoleic acid, and ε-caprolactone, which are polymers capable of forming a graft bond by amidation reaction with a group. 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 exemplified as the branched polymer portion. 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.

  As the organic pigment used in the pigment dispersion composition of the present invention, the same organic pigment as exemplified in the description of the organic pigment acidic derivative can be used as appropriate, and the organic pigment used as the raw material of the organic pigment acidic derivative. The compound may be the same as or different from the compound, and the combination is appropriately selected so as to obtain a desired color.

The blending ratio of the pigment dispersion composition of the present invention is preferably in the following range from the viewpoint of fine dispersibility, that is, lightness and color saturation.
First, the blending ratio of the organic pigment and its acidic derivative is preferably selected so that the amount of acidic groups of the blend is in the range of 10 ⁻⁵ to 10 ⁻⁶ mol / g, although the weight part varies depending on the type. . Next, the blending ratio of the organic pigment and its acidic derivative / cationic comb-shaped graft polymer / organic solvent is appropriately selected so as to obtain the desired brightness and saturation, but generally 100 parts by weight. The range of / 5/495 to 100/50/450 is preferred.

  To the pigment dispersion composition of the present invention, a thixotropy imparting agent, a leveling agent, and the like can be appropriately added as other components in order to improve suitability according to the coating method. Examples of the thixotropic agent include colloidal silica, bentonite, and polyamide wax, and examples of the leveling agent include various silicone oils.

  As the organic solvent used in the pigment dispersion composition of the present invention, ethers, esters, ketones, polyhydric alcohol derivatives, nitrogen-containing solvents, etc. are used from the viewpoint of excellent pigment dispersibility and resin solubility as a dispersion medium. Is preferred. Specific examples of the ketones include cyclohexanone and ethyl butyl ketone, examples of the polyhydric alcohol derivative include ethylene glycol monoethyl ether acetate and propylene glycol monomethyl ether acetate, and examples of the nitrogen-containing solvent include dimethylformamide. .

  Various dispersion machines such as a roll mill, a ball mill, a bead mill, a sand mill, a homomixer, and a homogenizer can be used for the production of the pigment dispersion composition of the present invention. preferable.

A color resist ink can be prepared by blending the photosensitive resin composition with the pigment dispersion composition of the present invention.
The photosensitive resin composition here contains a photopolymerizable monomer or oligomer, a photopolymerization initiator, a photosensitizer and a solvent as main components.

  The blending ratio of the pigment dispersion composition and the photosensitive resin composition is appropriately selected according to the required degree of color characteristics, exposure sensitivity, and developability, but in general, the pigment dispersion / The photosensitive resin is preferably in the range of 5/95 to 30/70.

  Examples of photopolymerizable monomers or oligomers include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) Acrylate, triethylene glycol (meth) acrylate, tetraethylene glycol di (meth) acrylate, tetramethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, pentaerythritol di ( (Meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) (Meth) acrylic acid such as acrylate, dipentaerythritol hexa (meth) acrylate, glycerol (meth) acrylate, bisphenol A type epoxy di (meth) acrylate, bisphenol F type epoxy di (meth) acrylate, bisphenolfluorene type epoxy di (meth) acrylate One type or a combination of two or more types of esters can be exemplified.

  Examples of photopolymerization initiators include acetophenones such as acetophenone, 2,2′-diethoxyacetophenone, p-dimethylacetophenone, p-tert-butylacetophenone, benzophenone, 2-chlorobenzophenone, p, p′-bisdimethyl. Benzophenones such as aminobenzophenone, benzoin ethers such as benzoin methyl ether, benzoin isopropyl ether and benzoin isobutyl ether, 2-methyl-1- [4- (methylthio) phenyl] -2-monfolinopropanone-1,2 Α-aminoalkylphenones such as benzyl-2-dimethylamino-1- (4-morpholiophenyl) -butanone-1, benzyldimethyl ketal, thioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxa Sulfur compounds such as Son a can be mentioned a combination of one or two or more.

  Examples of photosensitizers include p-dimethylaminobenzoic acid isoamyl ester, p-dimethylaminobenzoic acid ethyl ester, 4,4′-bis (dimethylamino) benzophenone, or a combination of one or more. Can be mentioned.

  Examples of the solvent include one or a combination of two or more types of ketones such as methyl isobutyl ketone, diisobutyl ketone and cyclohexanone, and cellosolves such as methyl cellosolve, ethyl cellosolve and ethyl cellosolve acetate.

  In the present invention, a pigment fine dispersion composition having a small average particle size can be obtained by combining a cationic comb-shaped graft polymer and an acidic derivative of an organic pigment as a fine dispersion component. This is presumed to be due to the following reason.

  That is, an acidic derivative of an organic pigment blended in the pigment dispersion composition covers the surface of the pigment particle, and the interface potential on the pigment particle side of the pigment-dispersion medium interfacial electric double layer is caused by the action of the acidic group of the derivative. It increases to the minus side, and the interface potential of the electric double layer increases. On the other hand, the backbone polymer part of the cationic comb graft polymer blended in the pigment dispersion composition together with the acidic derivative of the organic pigment has a positively charged cationic functional group, and has a negative potential increased by the above mechanism. The backbone polymer portion of the cationic comb graft polymer is strongly adsorbed by electrostatic attraction at the interface on the pigment particle side of the electric double layer, and the desorption of the cationic comb graft polymer from the pigment particles is reduced. The branched polymer portion grafted to the portion effectively exhibits a steric repulsion effect. Therefore, it is considered that the electrostatic repulsive force between the pigment particles and the steric repulsion effect of the branch polymer part work synergistically to promote fine dispersion and dispersion stability of the pigment particles.

  The pigment dispersion composition thus obtained is useful not only for color resist inks but also for ink jet printers that require high definition and automotive paints that require high gloss. It is. The color resist ink comprising the pigment dispersion composition and the photosensitive resin composition is also useful as an ultraviolet curable printing ink. For example, it can be used as a UV curable printing ink for paper containers, metal plates, and plastics utilizing high glossiness.

  Next, the present invention will be specifically described with reference to examples. Examples 1 to 9 and Comparative Examples 1 to 3 are examples related to the pigment dispersion composition, and Examples 10 to 12 and Comparative Examples 4 to 6 are related to the color resist ink.

Example 1
580 g of anthraquinonyl red as an organic pigment and 20 g of sulfonated quinacridone red as an acidic derivative of the organic pigment were dry blended to obtain a mixture having an acidic group content of 5.1 × 10 ⁻⁵ mol / g. Here, the amount of the acidic group was determined by accurately weighing 2 g of the above mixture in a 50 ml Erlenmeyer flask and adding 30 ml of 10 ⁻² mol / l tetrabutylammonium hydroxide-methylisobutylketone / benzene / methanol solution in an ultrasonic dispersing machine. after 1 hour adsorption reaction, and centrifuged, the resulting tetrabutylammonium hydroxide and 10 ^-2 mol / l perchloric acid remaining in supernatant - methyl isobutyl ketone, dioxane potentiometrically And measured.

  Next, 300 g of the above mixture, and 50 wt.% Of a cationic comb graft polymer having a basic group equivalent of 1350 g / eq consisting of polyethyleneimine in the trunk polymer part and poly (12-hydroxystearic acid) in the branch polymer part as the cationic comb graft polymer. % Propylene glycol monomethyl ether acetate solution 120 g (solid content of cationic comb-shaped graft polymer is 20 parts by weight with respect to 100 parts by weight of organic pigment-organic pigment acidic derivative mixture) and propylene glycol monomethyl ether acetate as an organic solvent serving as a dispersion medium 1080 g was blended in a 2 liter poly wide mouth bottle, sealed, and then manually shaken and mixed 4-5 times to prepare a raw material charged into the disperser.

Next, the charged raw material was charged into a continuous bead mill type disperser having a volume of 0.6 liter to disperse the pigment. The dispersion conditions are as follows.
<Distribution conditions>
・ Bead diameter: 0.3mmφ
・ Bead filling amount: 480 ml
・ Bead separator clearance: 0.1mm
Disk peripheral speed: 10.5m / s
・ Loading pressure: 0.1 bar
・ Number of charging passes: 3 passes

  The red pigment dispersion composition thus obtained had an average particle size of 94 nm as measured by a laser Doppler method, and excellent fine dispersion was achieved. Moreover, the viscosity in 25 degreeC measured by rotor rotation speed 6rpm and 60rpm using the B type viscometer was 220cp and 146cp, respectively. Accordingly, the viscosity ratio (Newtonian fluidity increases as the ratio of 6 rpm / 60 rpm is closer to 1) as a measure of Newtonian fluidity is 1.51, and Newtonian fluidity is large.

Example 2
519 g of copper-phthalocyanine blue as an organic pigment and 21 g of sulfonated phthalocyanine blue as an acidic derivative of an organic pigment were dry blended to obtain a mixture. When the acidic group amount of the obtained mixture was measured by the same method as in Example 1, it was 8.8 × 10 ⁻⁵ mol / g.

  Next, after blending 300 g of the above mixture, 120 g of the same cationic comb-shaped graft polymer solution used in Example 1 and 1080 g of the organic solvent, a blue pigment dispersion composition was prepared in the same procedure and conditions as in Example 1. Obtained.

  The average particle diameter measured by the laser Doppler method of the obtained pigment dispersion composition was 102 nm, and good fine dispersion was achieved. Further, the viscosity ratio measured in the same manner as in Example 1 was 2.16, and the Newtonian fluidity was large as the phthalocyanine blue pigment dispersion composition.

Example 3
566 g of salt brominated phthalocyanine green as an organic pigment and 34 g of sulfonated chlorinated phthalocyanine green as an acidic derivative of an organic pigment were dry blended to obtain a mixture. The amount of acidic groups of the obtained mixture was measured by the same method as in Example 1. As a result, it was 9.9 × 10 ⁻⁵ mol / g.

  Next, after blending 300 g of the above mixture, 120 g of the same cationic comb-shaped graft polymer solution and 1080 g of the organic solvent used in Example 1, a green pigment dispersion composition was prepared under the same procedure and conditions as in Example 1. Obtained.

  The average particle diameter measured by the laser Doppler method of the obtained pigment dispersion composition was 111 nm, and good fine dispersion was achieved. The viscosity ratio measured in the same manner as in Example 1 was 3.88, and the Newtonian fluidity was large as a phthalocyanine green pigment dispersion composition.

Example 4
575 g of the same organic pigment as in Example 1 was dry-blended with 25 g of terephthalic acid monoamidomethylated quinacridone red as an acidic derivative of the organic pigment to obtain a mixture. When the acidic group amount of the obtained mixture was measured in the same manner as in Example 1, it was 4.6 × 10 ⁻⁵ mol / g.

  Next, after blending 300 g of the above mixture, 120 g of the same cationic comb graft polymer solution and 1080 g of the organic solvent as in Example 1, a red pigment dispersion composition was obtained in the same procedure and conditions as in Example 1.

  The obtained pigment dispersion composition had an average particle size of 102 nm measured by the laser Doppler method, and the viscosity ratio measured in the same manner as in Example 1 was 1.57. Both sexes were excellent.

Example 5
300 g of a mixture of an organic pigment and an acidic derivative of an organic pigment similar to those in Example 1, and a basic group equivalent consisting of a poly (12-hydroxystearic acid) as a cationic polymer graft polymer, the trunk polymer part of which is polyethylene polyamine and the branched polymer part Was mixed with 120 g of a 50 wt% propylene glycol monomethyl ether acetate solution of a cationic comb-shaped graft polymer of 1470 g / eq and 1080 g of an organic solvent similar to that of Example 1, and then the red pigment dispersion was carried out in the same procedure and conditions as in Example 1. A body composition was obtained.

  The obtained pigment dispersion composition had an average particle diameter measured by laser Doppler method of 111 nm, and the viscosity ratio measured in the same manner as in Example 1 was 1.55. Fine dispersibility and Newtonian flow Both sexes were excellent.

Example 6
300 g of a mixture of an organic pigment and an acidic derivative of an organic pigment similar to Example 1, a cationic comb-shaped graft polymer having a trunk polymer portion of polyxylylene poly (2-hydroxypropylene) polyamine and a branch polymer portion of ε-caprolactone. After blending 120 g of a 50 wt% propylene glycol monomethyl ether acetate solution of a cationic comb-shaped graft polymer having a basic group equivalent weight of 1620 g / eq made of a ring polymer and 1080 g of an organic solvent similar to Example 1, the same as in Example 1 A red pigment dispersion composition was obtained under the procedures and conditions described above.

  The obtained pigment dispersion composition had an average particle diameter of 108 nm measured by a laser Doppler method, and the viscosity ratio measured in the same manner as in Example 1 was 1.43. Both sexes were excellent.

Example 7
300 g of a mixture of an organic pigment and an acidic derivative of an organic pigment similar to Example 1, a poly (aminomethylated) bisphenol A type epoxy resin as a cationic comb-shaped graft polymer, and an opening of a ε-cabrolactone as a branched polymer. Example 1 After blending 120 g of a 50 wt% propylene glycol monomethyl ether acetate solution of a cationic comb-shaped graft polymer having a basic group equivalent weight of 1250 g / eq made of a ring polymer and 1080 g of an organic solvent similar to Example 1, Example 1 A red pigment dispersion composition was obtained using the same procedure and conditions as in Example 1.

  The obtained pigment dispersion composition had an average particle diameter of 121 nm measured by a laser Doppler method, and a viscosity ratio measured in the same manner as in Example 1 was 1.61, and the fine dispersion property and Newtonian flow Both sexes were excellent.

Example 8
300 g of a mixture of an organic pigment and an acidic derivative of an organic pigment similar to those in Example 1, a dimethylaminomethylated glycidyl methacrylate-methacrylic acid esterified glycidyl methacrylate copolymer as a cationic comb-shaped graft polymer, a branch After blending 120 g of a 50 wt% propylene glycol monomethyl ether acetate solution of a cationic comb-shaped graft polymer having a polymer group consisting of methyl polymethacrylate having a basic group equivalent weight of 1180 g / eq, and 1080 g of an organic solvent similar to Example 1, A red pigment dispersion composition was obtained in the same procedure and conditions as in Example 1.

  The obtained pigment dispersion composition had an average particle size of 93 nm as measured by the laser Doppler method, and the viscosity ratio measured in the same manner as in Example 1 was 1.08. Both sexes were excellent.

Example 9
300 g of a mixture of an organic pigment and an acidic derivative of an organic pigment similar to those in Example 1, a dimethylaminoethyl methacrylate-methacrylic acid esterified glycidyl methacrylate copolymer, a branched polymer part as a cationic comb-shaped graft polymer Example 1 After blending 120 g of a 50 wt% propylene glycol monomethyl ether acetate solution of a cationic comb-shaped graft polymer having a basic group equivalent weight of 1270 g / eq consisting of methyl polymethacrylate and 1080 g of a dispersion medium similar to Example 1. A red pigment dispersion composition was obtained in the same procedure and conditions as in 1.

  The obtained pigment dispersion composition had an average particle size of 95 nm measured by the laser Doppler method, and the viscosity ratio measured in the same manner as in Example 1 was 1.10. Both sexes were excellent.

Comparative Example 1
A red pigment dispersion composition was obtained according to the procedure and conditions of Example 1 except that sulfonated quinacridone red as an acidic derivative of the organic pigment was not blended.

  The obtained pigment dispersion composition had an average particle size of 320 nm measured by the laser Doppler method, and the viscosity ratio measured in the same manner as in Example 1 was 6.95. Both sexes were inferior.

Comparative Example 2
Example 2 except that a cationic tail polymer obtained by amidation reaction of a terminal carboxylic acid of poly (12-hydroxystearic acid) and an amino group of 3-diaminopropylamine was used instead of the cationic comb-shaped graft polymer. A blue pigment dispersion composition was obtained by the same procedure and conditions as in Example 1.

  The obtained pigment dispersion composition had an average particle diameter measured by laser Doppler method of 1182 nm, and the viscosity ratio measured in the same manner as in Example 1 was 10 or more (greater than the upper limit of measurement), and the fine dispersion Both conversion and Newtonian liquidity were inferior.

Comparative Example 3
A green pigment dispersion composition was obtained by the same procedure and conditions as in Example 3 except that sulfonated chlorinated phthalocyanine green as an acidic derivative of an organic pigment was not blended.

  The obtained pigment dispersion composition had an average particle diameter measured by laser Doppler method of 632 nm, and the viscosity ratio measured in the same manner as in Example 1 was 10 or more. Both fine dispersibility and Newtonian fluidity were obtained. It was inferior.

Example 10
8 g of the red pigment dispersion composition prepared in Example 1, 15 g of the photosensitive resin composition having the following composition and 77 g of propylene glycol monomethyl ether acetate as an additional organic solvent were blended in a 300 ml beaker, and then stirred and mixed with a motor blade. A red color resist ink was prepared.

<Photosensitive resin composition>
・ Bisphenol fluorene type epoxy acrylate resin
20.9 parts by weight Dipentaerythritol hexaacrylate resin 9.0 parts by weight 4,4'-bis (dimethylamino) benzophenone 0.2 Parts by weight 2-methyl-1- {4- (methylthio) phenyl}
-2-Monfolinopropane-1 ... 1.2 parts by weight Propylene glycol monomethyl ether acetate ... 68.7 parts by weight

  When the above color resist ink was applied on a glass substrate on which a black matrix had been formed in advance using a spin coater under the conditions of rotational speed × time = 800 rpm × 10 seconds, a beautiful coating film with no coating unevenness was obtained. . Next, an ultraviolet mercury lamp was irradiated to an exposure dose of 100 mj / m 2 to photo-cure the coating film, followed by pre-baking treatment at 80 ° C. for 5 minutes, followed by alkali development with 0.4 wt% sodium carbonate aqueous solution. And a post-baking treatment at 200 ° C. for 1 hour was performed to prepare a red color filter having a film thickness of 1.5 μm.

  When the spectral transmittance of the obtained color filter was measured, the maximum value showed a high value of 93% and was excellent in lightness-saturation. Further, the amount of light when the two polarizing plates sandwiching the color filter were parallel and the amount of light when crossed were measured, and the contrast ratio was calculated. As a result, the parallel light quantity was 68.23, the cross light quantity was 0.106, and the contrast ratio was as high as 645.

Example 11
A blue color resist ink is prepared according to the same conditions and procedures as in Example 10 except that the blue pigment dispersion composition prepared in Example 2 is used as the pigment dispersion composition, and a coating film is formed on the glass substrate. As a result, a beautiful coating film without unevenness was formed. Subsequently, photocuring, pre-baking, alkali development, and post-baking were performed under the same conditions and procedures as in Example 10 to obtain a blue color filter. The maximum value of the spectral transmittance of the obtained color filter was 81%, The contrast ratio calculated in the same manner as in Example 10 was 989, and both values were high for blue.

Example 12
A green color resist ink was prepared according to the same conditions and procedures as in Example 10 except that the green pigment dispersion composition prepared in Example 3 was used as the pigment dispersion composition, and a coating film was formed on the glass substrate. As a result, a beautiful coating film without unevenness was formed. Subsequently, photocuring, pre-baking, alkali development, and post-baking were performed under the same conditions and procedures as in Example 10 to obtain a green color filter. The maximum value of the spectral transmittance of the obtained color filter was 80%, The contrast ratio calculated in the same manner as in Example 10 was 605, and both values were high as green.

Comparative Example 4
A red color resist ink was prepared according to the same conditions and procedures as in Example 10 except that the red pigment dispersion composition prepared in Comparative Example 1 was used as the pigment dispersion composition, and a coating film was formed on the glass substrate. However, color unevenness was observed in the obtained coating film. Further, photocuring, pre-baking, alkali development, and post-baking were each performed under the same conditions and procedures as in Example 10 to obtain a red color filter. The maximum value of the spectral transmittance of the obtained color filter was 88. %, The contrast ratio calculated in the same manner as in Example 10 was 131, and both values were low.

Comparative Example 5
A blue color resist ink was prepared according to the same conditions and procedures as in Example 10 except that the blue pigment dispersion composition prepared in Comparative Example 2 was used as the pigment dispersion composition, and a coating film was formed on the glass substrate. However, remarkable color unevenness was recognized in the obtained coating film. Further, photocuring, pre-baking, alkali development and post-baking were carried out under the same conditions and procedures as in Example 10 to obtain a blue color filter. The maximum value of the spectral transmittance of the obtained color filter was 71. %, The contrast ratio calculated in the same manner as in Example 10 was 96, and both values were low and inferior.

Comparative Example 6
A green color resist ink was prepared according to the same conditions and procedures as in Example 10 except that the green pigment dispersion composition prepared in Comparative Example 3 was used as the pigment dispersion composition, and a coating film was formed on the glass substrate. However, remarkable color unevenness was recognized in the obtained coating film. Further, photocuring, pre-baking, alkali development, and post-baking were carried out under the same conditions and procedures as in Example 6 to obtain a green color filter. The maximum value of the spectral transmittance of the obtained color filter was 70. %, The contrast ratio calculated in the same manner as in Example 10 was 111, and both values were low and inferior.

Claims (2)

In the pigment dispersion composition comprising an organic pigment, an organic solvent, and a finely dispersed component, the finely dispersed component comprises an acidic derivative of the organic pigment and a cationic comb graft polymer having a cationic functional group in the trunk polymer portion,
The cationic comb graft polymer is a polymer composed of a trunk polymer part having an amino group and a branch polymer part soluble in an organic solvent, and is a polymer formed by grafting two or more branch polymers to one molecule of the trunk polymer,
A pigment dispersion composition for a color resist ink , having a viscosity ratio of 1.51 or less and an average particle size of 94 nm or less .   The pigment dispersion composition for a color resist ink according to claim 1, wherein the organic solvent is an ether, ester, ketone, polyhydric alcohol derivative, or nitrogen-containing solvent.