JP2008304521A - Colored composition for color filter, method for manufacturing color filter, and color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a colored composition for color filters excellent in display color properties such as luminance and contrast. <P>SOLUTION: The colored composition for color filters includes a pigment and a resin varnish, wherein the pigment is a mixed pigment of two or more pigments having the same hue or similar hues. The mixed pigment is prepared by independently grinding two or more such crude pigments with a water-soluble inorganic salt, mixing the ground products in a predetermined ratio, and removing the water-soluble inorganic salt from the mixture. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a coloring composition for a color filter used in the production of a liquid crystal color display, an imaging device, and the like, and a color filter using the same. More specifically, the present invention relates to a coloring composition that gives a color filter excellent in display color characteristics such as luminance and contrast, and a color filter using the same.

  Color filters used in liquid crystal displays, etc. are currently applied to a substrate by a spin coating method, slit coating method, electrodeposition method, or transfer method using a coloring composition in which a pigment is dispersed in a photoresist, and then passed through a photomask. It is mainly produced using a pigment dispersion method in which a colored pattern is formed through exposure and then development.

  Conventional color filters were mainly used for personal computer displays, car navigation systems, and mobile phone displays. However, with the increase in the size of the panel manufacturing substrate, large LCD panels of 32 inches or more can now be manufactured at low cost. Applications are expanding rapidly. Along with this, the improvement in color reproducibility and contrast, which was inferior in the liquid crystal display compared with the display quality of CRT and PDP, has been demanded.

  The color filter of the first generation of the liquid crystal display was manufactured by creating a pattern with a transparent photoresist, immersing it in a dye bath, and dyeing the pattern. In a color filter using a dye, since the dye is present in a molecular pattern in the coloring pattern, light scattering by the pigment particles does not occur, and the polarization of light is not disturbed at all. Therefore, the contrast of the color filter using the dye shows a very high value.

  Thereafter, a pigment dispersion method using a pigment dispersion in which a pigment covering heat resistance and light resistance, which are weak points of dyes, was finely dispersed in a photoresist was developed and replaced by a dyeing method. However, in the pigment dispersion method, no matter how fine the pigment is, the polarization is disturbed due to light scattering, interference, reflection, etc. on the pigment particle surface due to the particle properties of the pigment, and a slight orthogonal component to the polarization plane is generated.

  In a liquid crystal display, when the liquid crystal molecules of the panel are shut, the light leakage theoretically becomes zero, but the light leaks due to this slight orthogonal component, and the contrast, which is the ratio of the parallel luminance and the orthogonal luminance, is low. End up. Therefore, liquid crystal panels using color filters based on the pigment dispersion method are considered to be inferior in display quality to CRT, etc., because the gradation is narrow so that black, which should originally be jet black, becomes dark gray. It was.

  A color filter that uses a dye that selectively absorbs and transmits light is used when a pigment is used instead of a dye because the dye is present in a molecular pattern in the coloring pattern and the contrast is very high. It has been proposed that if the primary particles of the particles are made smaller and close to the dye molecules, light scattering caused by the pigment particles can be suppressed and the contrast of the color filter can be increased. For example, Patent Document 1 and Patent Document 2 propose that there is an effect of improving contrast when a pigment is refined by salt milling to reduce the particle diameter and used in a color filter.

  Salt milling involves kneading pigments, organic solvents and water-soluble inorganic salts with a kneader, etc., pouring the kneaded material into a large amount of water, stirring at high speed, washing with filtered water, drying and grinding, and fine pigment. How to get.

  Further, in Patent Document 3, the dispersibility and transparency are improved by a method in which a phthalocyanine green pigment as a main pigment and a yellow organic pigment as a complementary color pigment are ground together (hereinafter sometimes referred to as “co-grinding”). It has been proposed that pigments with a high Y value) and coloring power can be obtained.

JP-A-8-179111 Japanese Patent Laid-Open No. 2003-227921 JP 2003-183535 A

  Liquid crystal panel manufacturers are demanding a dramatic increase in the contrast of current color filters in order to achieve image quality levels comparable to CRT and PDP quality displays. However, by using the above-described salt milling method and co-grinding method of the pigment, it is difficult to drastically improve the contrast by making the pigment finer, and further drastic improvement of these is demanded.

  As a result of diligent research to solve the above-described problems in pigment miniaturization and to develop a pigment miniaturization method capable of improving the contrast of a color filter, the present inventors have obtained a mixed pigment composed of two or more types of pigments. The present invention has been found to produce a mixed pigment useful as a color filter colorant that is effective in preventing secondary aggregation of fine pigments, is easily dispersed, and has excellent contrast by producing in a specific process. It came to complete.

  The above object is achieved by the present invention described below. That is, the present invention provides a color filter coloring composition comprising a pigment and a resin varnish, wherein the pigment is a mixed pigment of two or more of the same hue or a similar hue, and the mixed pigment is the two or more of the above Each of the crude pigments is pulverized with a water-soluble inorganic salt alone and mixed at a predetermined ratio, and the water-soluble inorganic salt is removed from the mixture (hereinafter sometimes referred to as “co-demineralization”). A colored composition for a color filter is provided.

  In the coloring composition for a color filter, the content of one of the pigments constituting the mixed pigment is at least 3% by mass of the mixed pigment; the combination of the two or more pigments is as follows: C. I. A combination of at least two selected from Pigment Red (PR) 254, PR177, and PR242; I. A combination of Pigment Green (PG) 36 and PG7, C.I. I. A combination of at least two selected from pigment yellow (PY) 138, PY139, PY150, and PY185, or C.I. I. Pigment Blue (PB) 15: 6 and C.I. I. It is preferably a combination with Pigment Violet (PV) 23. The pigment particles of the mixed pigment are preferably coated with a resin.

  Further, the present invention is characterized in that, in the method for producing a color filter including a step of forming a color pattern on the color filter substrate, the color pattern is formed using the color filter color composition of the present invention. And a color filter obtained by the method.

  In the present invention, the pigment before grinding treatment is sometimes referred to as “crude pigment”, while the pigment after grinding treatment is sometimes referred to as “ground pigment” or simply “pigment”.

  The pigment used in the coloring composition for color filters of the present invention is obtained by grinding two or more kinds of crude pigments having the same hue or similar hues, respectively, and mixing both of the ground pigments for co-desalting. Thus, the mutual affinity between the ground pigments is remarkably improved. On the other hand, in co-grinding of pigments, the hardness of two or more kinds of crude pigments is different, and if the grinding of one crude pigment proceeds, the grinding of the other coarse pigment may not proceed, In some cases, the crystal structure of the ground pigment was destroyed due to excessive progress. For example, when co-grinding PR177 and PR254 mainly used for television, the refinement of PR177 proceeds excessively, and the cohesive strength of the PR177 pigment particles after dry grinding becomes strong. Even if such a pigment is dispersed, it cannot be dispersed to the level of primary particles, and even if a color filter is formed using the pigment dispersion, the contrast does not increase.

  In the present invention, two or more kinds of coarse pigments having the same hue or similar hues are pulverized independently, whereby each coarse pigment can be ground and refined under optimum conditions, and the optimum primary particle size and shape can be obtained. Is obtained. The mixed pigments obtained by co-desalting each of the ground materials obtained in this way after mixing at a predetermined ratio, when used as a color pattern forming pigment for a color filter, give a color pattern with excellent contrast. The contrast is remarkably superior to the contrast of a color filter obtained when a pigment mixture obtained by co-dispersion or co-grinding of pigment is used.

  The reason why the contrast is improved is not clear, but two or more kinds of optimally ground two or more pigment grinds are mixed at a predetermined ratio, and stirred at high speed in water for co-desalting. This is probably because the primary particles of the pigments do not agglomerate with each other even after dry pulverization, and in the micro state, two or more types of pigment particles exist in a uniform mixed state. A color resist (color filter coloring composition) in which this mixed pigment is dispersed has two or more types of pigments refined at an optimum level even if a colored pattern of the color filter is formed through the coating and patterning steps. In addition, since it is uniformly mixed at the primary particle level, the contrast of the obtained color filter is considered to be high.

  On the other hand, when two or more kinds of pigments are mixed after dry pulverization, the respective pigments cause secondary agglomeration, and it is difficult to disperse to primary particles in a normal dispersion process. Therefore, it is estimated that the contrast of the color filter is lowered because it is present in the colored pattern film of the color filter.

  Further, the mixed pigment of the present invention is prevented from secondary aggregation of the pigment particles during dry pulverization by applying a resin treatment after grinding or co-desalting or after completion of co-desalting with the pigment alone. Can easily disperse to near the primary particle level.

Next, the present invention will be described in more detail with reference to preferred embodiments.
The pigment used in the present invention is a pigment mainly used for forming a color pattern of each color of a color filter, and examples of the red pigment include a color index (CI) PR56, 58, 122, 166. 168, 176, 177, 178, 224, 242, 254, green pigments include PG7, 36, and blue pigments include PB15: 1, 15: 3, 15: 6, 60, 80. Etc.

  Examples of yellow pigments include PY12, 13, 14, 17, 24, 55, 60, 74, 83, 90, 93, 126, 128, 138, 139, 150, 154, 155, 180, 185, 216, 219, Examples of purple pigments include PV19 and 23. In the present invention, the blue pigment and the violet pigment are referred to as pigments having similar hues.

  The combination of the above pigments is not particularly limited, but the two or more pigments constituting the mixed pigment are preferably pigments of the same hue or similar hues, and one of the pigments constituting the mixed pigment Is preferably at least 3% by mass of the mixed pigment. For example, when two kinds of pigments are mixed, if the ratio of one kind of pigment is less than 3% by mass, it is difficult to achieve the object of the present invention. The combination of the two or more pigments is at least two selected from PR254, 177 and 242; a combination of PG36 and 7; and at least two combinations selected from PY138, 139, 150 and 185, Or it is preferable that it is a combination of PB15: 6 and PV23.

  In the coloring composition for a color filter of the present invention, the above-mentioned two or more kinds of crude pigments are individually pulverized together with a water-soluble inorganic salt as a colorant, and then mixed at a predetermined ratio to obtain a water-soluble inorganic salt from the mixture. It is characterized by using a mixed pigment obtained by co-desalting.

  The crude pigment is ground using a known grinder such as a kneader having a strong shearing force in the presence of a water-soluble inorganic salt, preferably in the presence of an organic solvent. Examples of the water-soluble inorganic salt include sodium chloride, potassium chloride, sodium sulfate and the like. The organic solvent is preferably water-soluble. Moreover, since temperature rises at the time of grinding, a solvent with a high boiling point is preferable in consideration of safety. Examples of such solvents include diethylene glycol, diethylene glycol monoalkyl ether, triethylene glycol, triethylene glycol monoalkyl ether, liquid polyethylene glycol, alkoxyalkanol, dipropylene glycol, dipropylene glycol monoalkyl ether, and low molecular weight polypropylene glycol. Is mentioned.

  The ratio of the pigment, the organic solvent and the water-soluble inorganic salt in the grinding of the crude pigment is not particularly limited, but generally 200 to 2,500 parts by mass of the water-soluble inorganic salt and 100% by mass of the organic pigment with respect to 100 parts by mass of the crude pigment. It is 1-500 mass parts of solvent. The grinding of the crude pigment is preferably performed at a temperature of 20 to 150 ° C. for 2 to 36 hours.

  The ground product of two or more kinds of crude pigments obtained as described above is mixed and co-desalted so as to obtain transmitted light having a desired wavelength when a colored pattern is formed. In the co-desalting, each ground product is put into a large amount of water, stirred at high speed while heating, then filtered, and the resulting wet cake is washed to separate the organic solvent and the inorganic salt. Preferably, the obtained wet cake may be added again to water, suspended, and filtered and washed. The obtained wet cake is dried and pulverized to obtain the mixed pigment used in the present invention.

  In the above method, a complementary color pigment for adjusting the transmission wavelength of the color filter can be further added to the combination of two or more pigments. Use of these complementary color pigments is described in, for example, Japanese Patent Application No. 2006-133241. The use ratio of the complementary color pigment cannot be specified unconditionally depending on the pigment type.

  In the present invention, it is preferable to coat the pigment particles of the mixed pigment with a resin in order to prevent the ground pigment from agglomerating and to improve dispersibility. The coating of the pigment particles with the resin may be performed by adding a resin at the time of grinding the crude pigment, may be added at the time of mixing the coarse pigment ground product, or may be added at the time of the co-desalting or after the co-desalting. Also good. In the above, the addition amount of the resin is preferably 0.5 to 100 parts by mass per 100 parts by mass of the pigment.

  As a resin that can be added at the time of grinding, either a natural resin or a synthetic resin is used. For example, rosin, rosin modified resin, rubber derivative, epoxy resin, acrylic resin, maleic acid resin, butyral resin, polyester resin, phenol resin, melamine resin, urethane resin and the like can be mentioned. Among these resins, in the case of a water-insoluble resin, it is preferable to add at the time of pigment grinding.

  As the resin added at the time of co-desalting or after co-desalting, it is preferable to use a water-soluble resin or an acid- or alkali-soluble water-soluble resin. Examples thereof include water-soluble rosin, rosin-modified resin, acrylic resin, maleic acid resin, butyral resin, polyester resin, melamine resin, and urethane resin. In the case of a completely water-soluble resin, a poor solvent such as methanol, ethanol or propanol that is miscible with water is added to the pigment water slurry, and the resin is precipitated on the pigment particle surface. In the case of an acid- or alkali-soluble water-soluble resin, a resin-coated pigment can be obtained by, for example, a method in which the resin is insolubilized by adjusting the pH of the pigment water slurry after the resin is added and the resin is precipitated on the pigment particle surface. .

  The mixed pigments obtained as described above each have an optimal primary particle size and shape, and are in a uniform mixed state even at the micro level. Further, when the pigment particles are coated with a resin, the influence of secondary aggregation of the pigment particles due to dry pulverization can be minimized. As a result, the pigment particles of two or more pigments in the color filter coloring composition obtained by dispersing the mixed pigment are uniformly distributed in the formed colored pattern film and exist as finer particles. Therefore, the contrast of the obtained color filter is considered to be high.

  The coloring composition for a color filter of the present invention is composed of the above-mentioned mixed pigment (or resin-coated mixed pigment) and a resin varnish, and may further contain a pigment dispersant. Although the usage-amount of a pigment is not specifically limited, Usually, it is used in the ratio of 5-500 mass parts per 100 mass parts of resin binders of the below-mentioned resin varnish.

  In the present invention, as the resin varnish for dispersing a pigment to obtain a colored composition, a known resin varnish conventionally used for a colored composition for a color filter is used, and is not particularly limited. Moreover, a solvent and an aqueous medium suitable for the resin varnish are used as the medium. Further, conventionally known additives such as pigment dispersants, dispersion aids, coating film smoothing agents, adhesive agents and the like are appropriately added and used as necessary.

  As the resin varnish, a photosensitive resin varnish and a non-photosensitive resin varnish are used. Examples of the photosensitive resin varnish include photosensitive resin varnishes used in ultraviolet curable inks and electron beam curable inks. Non-photosensitive resin varnishes include, for example, letterpress ink, planographic ink, and intaglio gravure ink. Resin varnishes used for printing inks such as stencil screen ink, resin varnishes used for inkjet printing, resin varnishes used for electrodeposition coating, resin varnishes used for developers of electronic printing and electrostatic printing, thermal transfer films or ribbons Resin varnish used for the above.

  Specific examples of the photosensitive resin varnish include, for example, photosensitive cyclized rubber resins, photosensitive phenol resins, photosensitive polyacrylate resins, photosensitive polyamide resins, photosensitive polyimide resins, and unsaturated polyesters. Varnishes such as polyester resins, polyester acrylate resins, polyepoxy acrylate resins, polyurethane acrylate resins, polyether acrylate resins, polyol acrylate resins, or varnishes to which monomers are further added as reactive diluents. It is done. As a suitable resin among the photosensitive resin varnishes, an acrylate resin having a free carboxylic acid in an alkali developable molecule is desirable.

  Specific examples of the non-photosensitive resin varnish include, for example, a cellulose acetate resin, a nitrocellulose resin, a styrene (co) polymer, a polyvinyl butyral resin, an aminoalkyd resin, a polyester resin, and an amino resin modified polyester. Water-soluble resin, polyurethane resin, acrylic polyol urethane resin, soluble polyamide resin, soluble polyimide resin, soluble polyamideimide resin, soluble polyesterimide resin, hydroxyethyl cellulose, styrene-maleic acid ester copolymer Salts, water-soluble salts of (meth) acrylic acid ester-based (co) polymers, water-soluble amino alkyd resins, water-soluble amino polyester resins, water-soluble polyamide resins, and the like. These may be used alone or in combination of two or more. Used in combination It is.

Although the manufacturing method in particular of the coloring composition for color filters comprised from said each component of this invention is not restrict | limited, For example, the following method etc. are mentioned.
(A) A method in which the co-desalted wet cake is uniformly suspended again in water, added to the resin varnish, the mixed pigment is transferred to the varnish, flushed and kneaded.
(B) A method in which a pigment and a solvent to be used are finely dispersed with a wet medium disperser such as an attritor or a ball mill, and added to a resin varnish for kneading.
(C) A method in which a pigment and a solvent are added to a resin varnish at the time of premixing and the dispersion treatment is performed by a wet medium disperser.

  When producing a color filter using the colored composition for a color filter of the present invention, when a photosensitive resin varnish is used as the resin varnish, conventionally known photopolymerization such as benzoin ether and benzophenone is used in the composition. It is used as a photosensitive coloring composition prepared by adding an initiator and kneading by a conventionally known method. Moreover, it can replace with said photoinitiator and can also use it as a thermopolymerizable coloring composition using a thermal polymerization initiator.

  When forming a colored pattern of a color filter on a substrate using the photosensitive coloring composition, the photosensitive coloring composition is formed on a transparent substrate, for example, a spin coater, a low-speed rotation coater, a roll coater, a knife. Use a coater, slit coater, etc. to coat the entire surface, or print the entire surface by various printing methods or a slightly larger part than the colored pattern, and after pre-drying, attach a photomask and expose using an ultra-high pressure mercury lamp. To print the colored pattern. Subsequently, development and washing are performed, and a post-baking is performed as necessary to form a color filter coloring pattern. The coloring pattern forming method of these color filters is known per se, and the coloring pattern forming method of the color filter is not particularly limited in the present invention.

  When forming a color filter color pattern using the color filter coloring composition of the present invention (non-photosensitive color composition) using a non-photosensitive resin varnish, the non-photosensitive color composition is formed on a transparent substrate. For example, a color pattern is directly printed on a substrate by various printing methods described above as a color filter printing ink, and a color pattern is formed on a substrate by electrodeposition coating as an aqueous electrodeposition coating composition for a color filter. Method, a method of forming a colored pattern on a substrate by ink jet printing as an ink for ink jet, an electronic printing method or an electrostatic printing method, or a coloring pattern once formed on a transferable substrate by the above method or the like. Examples thereof include a method of transferring to a filter substrate. Then, according to a conventional method, baking is performed as necessary, polishing for smoothing the surface, or top coating for protecting the surface is performed. Further, an RGB color filter can be obtained by forming a black matrix according to a conventional method. The manufacturing methods of these color filters are known per se, and the manufacturing method of the color filters is not particularly limited in the present invention.

Next, the present invention will be described more specifically with reference to grinding examples, examples and comparative examples. In the text, “part” or “%” is based on mass.
[Crushing Example 1]
100 parts of a commercially available diketopyrrolopyrrole red pigment (PR254), 200 parts of diethylene glycol and 700 parts of sodium chloride are charged into a 3,000 volume part kneader and adjusted so that the temperature is maintained at 80 to 100 ° C. for 16 hours. The kneaded product R1 was obtained by grinding.

[Crushing example 2]
100 parts of a commercially available anthraquinonyl red pigment (PR177), 200 parts of diethylene glycol and 700 parts of sodium chloride are put into a 3,000 parts by volume kneader, adjusted to keep the temperature between 80 ° C. and 100 ° C., and polished for 8 hours. Crushing to obtain a kneaded product R2.

[Crushing Example 3]
100 parts of a commercially available disazo red pigment (PR242), 200 parts of diethylene glycol and 700 parts of sodium chloride are put in a 3,000 volume part kneader, adjusted so as to keep the temperature between 60 ° C. and 80 ° C., and milled for 8 hours. Thus, a kneaded product R3 was obtained.

[Crushing Example 4]
100 parts of commercially available isoindoline-based yellow pigment (PY139), 200 parts of diethylene glycol and 700 parts of sodium chloride are put into a 3,000 parts by volume kneader, adjusted so that the temperature is kept at 60 ° C. to 70 ° C., and milled for 10 hours. Thus, a kneaded material Y1 was obtained.

[Crushing Example 5]
100 parts of a commercially available quinophthalone yellow pigment (PY138), 200 parts of diethylene glycol and 700 parts of sodium chloride are put into a 3,000 volume part kneader, adjusted so as to keep the temperature between 60 ° C. and 70 ° C., and ground for 20 hours. Thus, a kneaded material Y2 was obtained.

[Crushing Example 6]
100 parts of a commercially available nickel azo yellow pigment (PY150), 200 parts of diethylene glycol and 700 parts of sodium chloride are put into a 3,000 volume part kneader, adjusted so as to keep the temperature between 80 ° C. and 100 ° C., and ground for 4 hours. Thus, a kneaded product Y3 was obtained.

[Crushing Example 7]
100 parts of a commercially available brominated phthalocyanine green pigment (PG36), 200 parts of diethylene glycol and 700 parts of sodium chloride are put in a kneader of 3,000 parts by volume, adjusted to keep the temperature between 100 ° C. and 120 ° C., and polished for 14 hours. Crushing to obtain a kneaded product G1.

[Crushing Example 8]
100 parts of a commercially available chlorinated phthalocyanine-based green pigment (PG7), 200 parts of diethylene glycol and 700 parts of sodium chloride are put into a 3,000 volume part kneader, adjusted so as to keep the temperature between 90 ° C. and 110 ° C., and polished for 12 hours. Crushing to obtain a kneaded product G2.

[Crushing example 9]
100 parts of commercially available ε-type phthalocyanine-based blue pigment (PB15: 6), 200 parts of diethylene glycol and 700 parts of sodium chloride are charged into a 3,000 part by volume kneader and adjusted so that the temperature is maintained at 100 ° C. to 120 ° C. After kneading for a time, a kneaded material B1 was obtained.

[Crushing Example 10]
100 parts of a commercially available dioxazine-based violet pigment (PV23), 200 parts of diethylene glycol and 700 parts of sodium chloride are put into a 3,000 volume part kneader, adjusted so that the temperature is maintained at 60 ° C. to 80 ° C., and milled for 8 hours. Thus, a kneaded material V1 was obtained.

[Example 1]
600 parts of kneaded product R1 of grinding example 1 and 400 parts of kneaded product R2 of grinding example 2 were put into 3,000 parts of water, heated to 80 ° C., heated at high speed for 4 hours. did. Next, filtration and washing were performed to obtain a wet cake of mixed pigment (pigment pure content: 29.3%). Subsequently, it dried at 80 degreeC all day and night, and obtained the red mixed pigment R (1). When TEM observation was performed, the average particle diameter of the primary particles was about 30 nm.

[Example 2]
The same procedure as in Example 1 was repeated except that 600 parts of the kneaded product R1 and 400 parts of the kneaded product R3 were used instead of the kneaded product R2 of Example 1, and the red mixed pigment R (2) Obtained. The average particle diameter of the primary particles by TEM observation was about 30 nm.

[Examples 3 to 10]
Except that the kneaded product obtained in the grinding example was changed to the ratio shown in Table 1, the same operation as in Example 1 was repeated to obtain mixed pigments Y (1) to B (2). The average particle diameter of the primary particles by TEM observation is as shown in Table 1.

[Example 11]
Example 1 to 50 parts of acrylic resin varnish (polymerized at a molar ratio of benzyl methacrylate / methacrylic acid / hydroxyethyl methacrylate = 70/15/15 /: molecular weight 12,000, acid value 100, solid content 40%) 15 parts of each of the mixed pigments of red (R), yellow (Y), green (G), and blue (B) obtained in 10; 10 parts of a polyurethane dispersant (solid content 46%); and a solvent (propylene glycol monomethyl) 25 parts of ether acetate (hereinafter abbreviated as PMA) was blended, and after premixing, the mixture was dispersed by a horizontal bead mill to obtain a base color for each color resist (10 types of colored composition for color filter).

  Further, 10 parts of each base collar obtained above was diluted with 10 parts of PMA and applied to a glass substrate having a thickness of 1.1 mm and a square of 100 mm using a spin coater. The coating conditions were 200 rotations for 5 seconds, and then further high speed rotation to prepare substrates (P1 to P10) having a colored film having a predetermined chromaticity.

[Comparative Example 1]
A mixed pigment kneaded material was prepared by co-grinding except that 60 parts of PR254 and 40 parts of PR177 were used in place of the pigment used in grinding example 1, and the mixture was poured into water. The organic solvent was removed, and then dry pulverization was performed to obtain a red mixed pigment HR (1). The average particle diameter of the primary particles by TEM observation was about 30 nm.

[Comparative Examples 2 to 10]
In place of the two pigments used in Comparative Example 1, the two pigments were the same as in Comparative Example 1 so that the mixing ratio of the pigments used in Examples 1 to 10 was the same as shown in Table 2. The mixed pigments (HR (2) to HB (2)) of Comparative Examples 2 to 10 were obtained. The average particle diameter of the primary particles obtained by TEM observation of these mixed pigments was almost the same as the values obtained in Examples 1-10.

[Comparative Example 11]
Using the mixed pigments HR1 to HB2 obtained in Comparative Examples 1 to 10 in the same manner as in Example 11, base colors of various colors for color resist (10 types of colored compositions for color filters) were obtained.

  Further, 10 parts of each base collar obtained above was diluted with 10 parts of PMA and applied to a glass substrate having a thickness of 1.1 mm and a square of 100 mm using a spin coater. The coating conditions were 200 rotations for 5 seconds, and then further high speed rotation to prepare substrates (H1 to H10) having a colored film having a predetermined chromaticity.

[Example 12]
The chromaticity of the colored substrates obtained in Example 11 and Comparative Example 11 was measured with a spectrophotometer (Hitachi U-3120 type), and the contrast was measured with the Keyakizaka electric contrast meter CT-1 type. The results are shown in Table 3.

  As is apparent from Table 3, the colored film obtained using the mixed pigment of the present invention as a colorant is superior in luminance and contrast as compared with the case of using a co-ground pigment.

[Example 13]
400 parts of the kneaded product R1 of grinding example 1, 400 parts of the kneaded product R2 of grinding example 2 and 200 parts of the kneaded product Y1 (complementary color pigment) of grinding example 4 were put into 2,000 parts of water, The mixture was heated to 80 ° C. and stirred at high speed for 4 hours. Next, filtration and washing were performed to obtain a wet cake of mixed pigment (pigment pure content: 29.3%). 240 parts of the obtained wet cake are put into 1,000 parts of water and re-peptized. Furthermore, after adding 35 parts of 40% aqueous solution of ammonia salt of benzyl methacrylate-methacrylic acid copolymer (weight average molecular weight 25,000, acid value 135), hydrochloric acid was dropped to lower the pH to precipitate the resin. To coat the pigment surface. Subsequently, filtration and washing were performed, and drying was performed at 80 ° C. for a whole day and night to obtain a red resin-coated mixed pigment 11. When TEM observation was performed, the average particle diameter of the primary particles was about 30 nm.

[Example 14]
Instead of 400 parts of the kneaded product R1 of Example 13, 400 parts of the kneaded product R2 of the grinding example 2 and 200 parts of the kneaded product Y1 (complementary color pigment) of the grinding example 4, the kneaded product G1 of the grinding example 7 The same procedure as in Example 13 was repeated except that 570 parts of the above, 30 parts of the kneaded product G2 of grinding example 8 and 400 parts of the kneaded product Y3 (complementary color pigment) of grinding example 6 were used. A resin-coated mixed pigment 12 was obtained. The average particle diameter of the primary particles by TEM observation was about 25 nm.

[Example 15]
Instead of 400 parts of the kneaded product R1 of Example 13, 400 parts of the kneaded product R2 of the grinding example 2 and 200 parts of the kneaded product Y1 (complementary color pigment) of the grinding example 4, the kneaded product B1 of the grinding example 9 A blue resin-coated mixed pigment 13 was obtained by repeating the same operation as in Example 13 except that 800 parts of No. 1 and 200 parts of the kneaded product V1 of Example 10 were used. The average particle diameter of the primary particles by TEM observation was about 25 nm.

[Comparative Example 12]
A mixed pigment kneaded material was prepared by co-grinding except that 40 parts of PR254, 40 parts of PR177 and 20 parts of PY139 were used in place of the pigment used in Comparative Example 1, and the mixture was added to water. Neutral inorganic salt and organic solvent were removed, followed by dry pulverization to obtain a red mixed pigment HR11. The average particle diameter of the primary particles by TEM observation was about 30 nm.

[Comparative Example 13]
A mixed pigment kneaded material was prepared by co-grinding, except that 57 parts of PG36, 3 parts of PG7, and 40 parts of PY150 were used instead of the pigment used in Comparative Example 12, and the mixture was added to water. The organic inorganic salt and the organic solvent were removed, followed by dry pulverization to obtain a green mixed pigment HG12. The average particle diameter of the primary particles by TEM observation was about 30 nm.

[Example 16]
Instead of the mixed pigment of Example 11, resin-coated pigments 11 to 13 of Examples 13 to 15 were used to obtain base colors (three types of colored compositions for color filters) for each color resist.

  Further, 10 parts of each base collar obtained above was diluted with 10 parts of PMA and applied to a glass substrate having a thickness of 1.1 mm and a square of 100 mm using a spin coater. The coating conditions were 200 rotations for 5 seconds, and then further high speed rotation to prepare substrates (P11 to P13) having a colored film with a predetermined chromaticity.

[Comparative Example 14]
In place of the mixed pigment of Example 16, the pigments HR11 and HG12 of Comparative Examples 12 and 13 were used to obtain base colors of color resists (two types of colored compositions for color filters).

  Further, 10 parts of the base collar obtained above was diluted with 10 parts of PMA, and applied to a glass substrate having a thickness of 1.1 mm and a square of 100 mm using a spin coater. The coating conditions were 200 rotations for 5 seconds, and then further high speed rotation to prepare substrates (H11, H12) having a colored film with a predetermined chromaticity.

[Example 17]
The chromaticity of the colored substrates obtained in Example 16 and Comparative Example 14 was measured with a spectrophotometer (Hitachi U-3120 type), and the contrast was measured with a Keyakizaka electric contrast meter CT-1 type. The results are shown in Table 4.

  As is apparent from Tables 3 and 4, the colored film obtained using the mixed pigment of the present invention as a colorant is superior in brightness and contrast as compared with the case of using the co-ground pigment.

[Example 18]
In order to produce RGB color filters, photosensitive color resists of R (red), G (green) and B (blue) were obtained according to the formulation shown in Table 5 below.

The glass substrate treated with the silane coupling agent was set on a spin coater, and the red color resist shown in Table 5 was first spin-coated at 300 rpm for 5 seconds and then at 1200 rpm for 5 seconds. Next, prebaking was performed at 80 ° C. for 10 minutes, a photomask having a mosaic pattern was brought into close contact, and exposure was performed with an ultrahigh pressure mercury lamp at a light amount of 100 mJ / cm ² . Next, development and washing were performed with a dedicated developer and a dedicated rinse to form a red mosaic pattern on the glass substrate.

  Subsequently, a green mosaic pattern and a blue mosaic pattern were formed by coating and baking according to the above method using the green and blue color resists shown in Table 5 to obtain RGB color filters. The resulting color filter has excellent spectral curve characteristics, excellent fastness such as light resistance and heat resistance, and excellent light transmission properties, and is excellent as a color filter for liquid crystal color displays. Showed the properties.

  According to the present invention, each single pigment is ground under optimum conditions, and a kneaded mixture of two or more pigments is co-desalted and preferably coated with a resin, thereby mixing with excellent contrast and brightness. A liquid crystal display incorporating a color filter created by applying a color resist that uses a dispersion obtained by dispersing pigment and then dispersing has a much improved displayable color range and excellent color reproducibility. Is obtained.

Claims (6)

  In a coloring composition for a color filter comprising a pigment and a resin varnish, the pigment is a mixed pigment of two or more of the same hue or a similar hue, and each of the mixed pigments is a combination of the two or more crude pigments. A colored composition for a color filter, which is a mixed pigment obtained by mixing a ground product with a water-soluble inorganic salt in a predetermined ratio and removing the water-soluble inorganic salt from the mixture.   The coloring composition for a color filter according to claim 1, wherein the content of one of the pigments constituting the mixed pigment is at least 3% by mass of the mixed pigment.   A combination of the two or more pigments is C.I. I. A combination of at least two selected from Pigment Red (PR) 254, PR177, and PR242; I. A combination of Pigment Green (PG) 36 and PG7, C.I. I. A combination of at least two selected from pigment yellow (PY) 138, PY139, PY150, and PY185, or C.I. I. Pigment Blue (PB) 15: 6 and C.I. I. The coloring composition for a color filter according to claim 1, which is a combination with Pigment Violet (PV) 23.   The coloring composition for a color filter according to claim 1, wherein the pigment particles of the mixed pigment are coated with a resin.   In the manufacturing method of the color filter including the process of forming a coloring pattern in the board | substrate for color filters, a coloring pattern is formed using the coloring composition for color filters of Claim 1, The color filter characterized by the above-mentioned. Production method.   A color filter obtained by the method according to claim 5.