Novel copolymer, pigment dispersion liquid, and photosensitive coloring composition

Abstract

[Problem] The present invention addresses the problem of providing a pigment dispersion liquid and a photosensitive coloring composition which can maintain a low viscosity and a high contrast at conventional levels while having good solubility in a developer solution, and can solve contradictory problems. [Solution] The present invention provides a copolymer which is obtained by copolymerizing (i) 100 parts by weight of a compound that is represented by formula (I), and (ii) 30-900 parts by weight of a compound that is copolymerizable with the compound of formula (I). (In formula (I), R1 and R3 may be different from each other and each represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group, R2 represents an alkyl group having 1 to 4 carbon atoms, which may have a substituent, and n represents an integer of 4 to 15.)

Description

Novel copolymer, pigment dispersion and photosensitive coloring composition

[0001] The present invention relates to a novel dispersant, a pigment dispersion, a photosensitive coloring composition, and a color filter.

[0002] Color filters used in liquid crystal display devices and solid-state imaging devices are generally manufactured by applying a coloring composition, which is prepared by dissolving or dispersing a dye or pigment coloring material in a solvent and blending it with a resin or the like, to a glass substrate, silicon substrate, or the like, followed by processes such as exposure and curing, development, and thermal curing. Since the durability of a color filter is related to the lifespan of the liquid crystal display device or solid-state imaging device, the pigment dispersion method, which uses a pigment with excellent heat resistance and solvent resistance as the coloring material of the coloring composition, has become mainstream. In the pigment dispersion method, a non-aqueous pigment dispersion liquid in which a pigment is dispersed in an organic solvent is mainly used.

[0003] In recent years, there has been a demand for color filters used in liquid crystal displays and solid-state imaging devices to have higher resolution and lower power consumption. To achieve these demands, there is a strong demand for color filters with color characteristics such as higher contrast, higher brightness, and higher coloring power.

[0004] In addition to the above-mentioned properties, the requirements for the manufacturing process of pigment dispersions and photosensitive coloring compositions are also becoming stricter. Specifically, as panels become larger, high-speed coating is required, so there is a demand for low viscosity pigment dispersions and photosensitive coloring compositions and improved solubility in alkaline developers. These requirements are often contradictory. This is because selecting a material that improves solubility in alkaline developers increases the viscosity of the pigment dispersions and photosensitive coloring compositions, making high-speed coating difficult.

[0005] Therefore, there is a demand for a pigment dispersion or a photosensitive coloring composition that can solve these conflicting problems, and that has good solubility in a developer while maintaining conventional levels of low viscosity and high contrast.

[0006] As a result of intensive research, the present inventors have found that a copolymer obtained by copolymerizing a specific compound solves the above-mentioned problems and can improve the solubility in a developer while maintaining the conventional low viscosity and high contrast, thereby arriving at the present invention. In particular, they have found that by introducing this specific compound into a conventionally known block copolymer, the copolymer exhibits excellent performance as a dispersant and is excellent in the effect of improving the solubility in a developer while maintaining the conventional low viscosity and high contrast, thereby completing the present invention.

[0007] According to the present invention, it has become possible to improve the developer solubility of a pigment dispersion liquid and a photosensitive resin composition (also referred to as a color resist, a color composition for a color filter, or a photosensitive color composition) while maintaining the conventional low viscosity and high contrast.

[0008] FIG. 2 is a schematic diagram illustrating a test method for evaluating developability in the examples.

[0009] That is, the present invention includes the following: (1) A copolymer obtained by copolymerizing at least (i) 100 parts by weight of a compound represented by the following formula (I) and (ii) 30 to 900 parts by weight of a compound copolymerizable with the compound of formula (I): (In formula (I), R 1 and R 3 are hydrogen or an alkyl or alkoxy group having 1 to 4 carbon atoms, which may be different from each other; R 2 represents an alkyl group having 1 to 4 carbon atoms which may have a substituent, and n represents an integer of 4 to 15.) (2) A pigment dispersion liquid containing at least the copolymer described in (1) above, a pigment, and a dispersion medium; (3) A method for producing a photosensitive coloring composition, which comprises mixing a pigment dispersion liquid containing at least the copolymer described in (1) above, a pigment, and a dispersion medium with at least a photopolymerizable monomer and a photopolymerization initiator; and (4) A photosensitive coloring composition, which comprises at least the copolymer described in (1) above, a pigment, a dispersion medium, a photopolymerizable monomer, and a photopolymerization initiator.

[0010] The present invention will be described below. (Pigment) The pigment dispersion of the present invention is a state in which a pigment is dispersed in a dispersion medium. Usable pigments are not particularly limited, and examples thereof include various pigments such as yellow pigments, orange pigments, red pigments, purple pigments, blue pigments, green pigments, brown pigments, black pigments, and white pigments. In terms of structure, pigments such as diketopyrrolopyrroles, azo pigments, phthalocyanines, quinacridones, benzimidazolones, isoindolinones, anthraquinones, azomethines, quinophthalones, isoindolines, benzimidazolones, pyrazolones, perinones, xanthenes, perylenes, and dioxazines can be used. In addition, inorganic pigments such as barium sulfate, titanium oxide, zirconium oxide, silicon oxide, red iron oxide, cobalt blue, and chromium oxide can also be used. Specific examples include the following.

[0011] As the yellow pigment, C.I. Pigment Yellow 1, 2, 3, 4, 5, 10, 12, 13, 14, 16, 17, 24, 32, 34, 35, 36, 37, 41, 42, 43, 49, 53, 55, 60, 61, 62, 63, 65, 73, 74, 75, 77, 81, 83, 93, 94, 95, 97, 98, 99, 100, 101, 104, 105, 106, 108, 109, 110, 111, 113, 123, 124 , 126, 127, 128, 129, 130, 138, 139, 150, 151, 152, 153, 154, 155, 165, 167, 168, 169, 170, 172, 173, 174, 175, 176, 179, 180, 181, 182, 183, 184, 185, 191, 193, 194, 199, 205, 206, 212, 213, 214, 215, 219.

[0012] Examples of orange pigments include C.I. Pigment Orange 1, 2, 4, 5, 13, 15, 16, 17, 19, 20, 21, 24, 31, 34, 36, 38, 40, 43, 46, 48, 49, 51, 60, 61, 62, 64, 65, 66, 67, 68, 69, 71, 72, 73, 74, and 81.

[0013] Red pigments include C.I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 21, 22, 23, 31, 32, 38, 41, 48, 48: 1, 48: 2, 48: 3, 48: 4, 48: 5, 49, 52, 52: 1, 52: 2, 53: 1, 54, 57: 1, 58, 60: 1, 63, 64: 1, 68, 81: 1, 83, 88, 89, 95, 101, 104, 105, 108, 112, 114, 119, 122, 123, 136, 144, 150, 164, 166, 168, 169, 170, 171 , 172, 175, 176, 177, 178, 179, 181, 182, 183, 184, 185, 187, 188, 190, 193, 194, 200, 202, 206, 207, 208, 209, 210, 211, 213, 214, 216, 220, 221, 224, 226, 237, 238, 239, 242, 245, 247, 248, 251, 253, 254, 255, 256, 257, 258, 260, 262, 263, 264, 266, 268, 269, 270, 271, 272, 279, and 291 are examples.

[0014] Purple pigments include C.I. Pigment Violet 1, 2, 3, 3:1, 3:3, 5:1, 13, 15, 16, 17, 19, 23, 25, 27, 29, 31, 32, 36, 37, 38, 42, and 50.

[0015] Examples of blue pigments include C.I. Pigment Blue 1, 15, 15:1, 15:2, 15:3, 15:4, 15:5, 15:6, 16, 17:1, 24, 24:1, 25, 26, 27, 28, 29, 36, 56, 60, 61, 62, 63, 75, 79, and 80. Examples of green pigments include C.I. Pigment Green 1, 4, 7, 8, 10, 15, 17, 26, 36, 50, 58, and 59.

[0016] While any of the above pigments can be used without restriction, it is preferable to subject them to various micronization treatments. The micronization method is not limited, and various known methods can be used. Examples include so-called salt milling, in which a pigment is milled with a water-soluble inorganic salt such as sodium chloride and then washed with water. The salt milling method is also not particularly limited, and examples include solvent salt milling, which uses an organic solvent, and dry salt milling, which does not use an organic solvent. In addition to this so-called salt milling method, various conventional techniques can be used, such as the so-called reprecipitation method or a method for micronizing organic pigments that combines the salt milling method and the reprecipitation method. Of these micronization methods, salt milling, particularly solvent salt milling, is preferred because it can produce uniform and fine pigment particles and is applicable to a wide range of pigments. During salt milling, in addition to the organic solvent and inorganic salt, a resin may be present as needed. The organic solvent is preferably a water-soluble organic solvent, and examples thereof include alcohols, ethers, and various glycols such as 2-(methoxymethoxy)ethanol, 2-butoxyethanol, 2-(isopentyloxy)ethanol, 2-(hexyloxy)ethanol, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol, triethylene glycol monomethyl ether, liquid polyethylene glycol, ethylene glycol, diethylene glycol, propylene glycol, etc. The resin used during salt milling is not particularly limited, and examples include natural resins, modified natural resins, synthetic resins, and synthetic resins modified with natural resins, but those that are solid at room temperature and insoluble in water are preferred.Examples of suitable resins include rosin, rosin derivatives, rosin-modified maleic acid resins, rosin-modified phenolic resins, rubber derivatives, protein derivatives, chlorinated polyethylene, chlorinated polypropylene, polyvinyl chloride, polyvinyl acetate, epoxy resins, acrylic resins, maleic acid resins, styrene resins, styrene-maleic acid copolymer resins, butyral resins, polyester resins, melamine resins, phenolic resins, polyurethane resins, polyamide resins, polyimide resins, alkyd resins, rubber-based resins, celluloses, benzoguanamine resins, and urea resins, as described in JP 2007-238852 A. The amount of resin used is typically 5 to 200 parts by weight per 100 parts by weight of pigment. By using a finely divided pigment having a primary particle diameter (average primary particle diameter as determined by electron microscopy) of 100 nm or less, particularly 80 nm or less, obtained by such a finely divided process, the viscosity of the resulting pigment dispersion and the photosensitive resin composition using the pigment dispersion can be maintained particularly low, resulting in a photosensitive resin composition with high developer solubility and a high contrast color filter. Although there are no limitations on the amount of pigment blended, it is generally 5 to 30% by weight, preferably 7 to 20% by weight, and more preferably 8 to 15% by weight in the dispersion. This range provides the best color development and dispersion stability; if it is less than 5% by weight, color development may be insufficient, and if it exceeds 30% by weight, dispersion stability may decrease.

[0017] (Dispersion medium) Generally, an organic solvent is used as the dispersion medium. Any solvent that is normally used in pigment dispersions for color filters or photosensitive coloring compositions can be used without any restrictions. Specifically, ether-based solvents such as ethylene glycol monomethyl ether (2-methoxyethanol), ethylene glycol monoethyl ether (cellosolve), ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether (butyl cellosolve), propylene glycol monomethyl ether (1-methoxy-2-propanol), propylene glycol monoethyl ether (1-ethoxy-2-propanol), propylene glycol isopropyl ether, and propylene glycol monobutyl ether (1-butoxy-2-propanol), ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monoisopropyl ether, and ethylene glycol monobutyl ether (1-butoxy-2-propanol), Examples of suitable solvents include ester-based solvents such as isopropyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether acetate, propylene glycol isopropyl ether acetate, propylene glycol monobutyl ether acetate, methoxybutyl acetate (methacetate), methyl lactate, and ethyl lactate; alcohol-based solvents such as methanol, ethanol, isopropanol, butanol, and diacetone alcohol (DAA); ketone-based solvents such as cyclohexanone; and nitrogen-containing solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone. These can be used alone or in combination of two or more. Among these solvents, from the viewpoints of dispersibility, coatability, safety, etc., propylene glycol monomethyl ether (1-methoxy-2-propanol), propylene glycol monoethyl ether (1-ethoxy-2-propanol), propylene glycol monomethyl ether acetate (PGMEA), methoxybutyl acetate, etc. are preferred.

[0018] (Copolymer of the Invention) 1. Monomer Structure The invention is characterized by containing the following copolymer. This copolymer has the function of dispersing pigments, i.e., functions as a pigment dispersant, and at the same time is characterized by improving the solubility of the photosensitive coloring composition in the developer. Improved developer solubility suppresses the generation of foreign matter that can cause image defects, thereby reducing the process of removing foreign matter and exhibiting the excellent effect of improving image quality. The copolymer of the invention is obtained by copolymerizing 100 parts by weight of an essential component (i) a compound represented by the following formula (I) with 30 to 900 parts by weight of (ii) a compound copolymerizable with this compound. Formula (I) In formula (I), R 1 and R 3 are hydrogen or an alkyl or alkoxy group having 1 to 4 carbon atoms, which may be different from each other; R 2 represents an alkyl group having 1 to 4 carbon atoms which may have a substituent, and n represents an integer of 4 to 15. 2 is preferably represented by the following chemical formula (II): R 4 , R 5 , R 6 and R 7 are each independently a hydrogen atom or an alkyl or alkoxy group having 1 to 4 carbon atoms. That is, a compound represented by the following chemical formula (III) is preferred. Among these, R 1 , R 3 , R 4 , R 5 , R 6 and R 7 are preferably hydrogen or alkyl groups having 2 or less carbon atoms which may be different from each other, more preferably hydrogen or methyl groups which may be different from each other. 1 , R 4 , R 5 , R 6 and R 7 is hydrogen, and R 3 is a methyl group.

[0019] n is preferably an integer of 4 to 12, more preferably an integer of 5 to 10, and most preferably n=9. This compound is an alkylene oxide adduct of an alkyl (meth)acrylate (alkoxypolyalkylene glycol alkyl (meth)acrylate), and the most preferred compound is methoxypolyethylene glycol (n=9) methacrylate (MPEG9MA). This compound can also be described as a (meth)acrylic acid ester of a polymer of an optionally substituted oxyalkylene (HO-R-OH) (R is an optionally substituted alkyl group) ((HO-R-OH)n, R is a main chain consisting of an alkyl group having 1 to 4 carbon atoms, which may have a methyl group as a substituent).

[0020] Next, component (ii) is a monomer polymerizable with the compound (i) described above, and is not particularly limited as long as it is polymerizable with the compound described above. It is sufficient that the component (ii) has a functional group capable of addition polymerization with the double bond possessed by compound (i). Specific examples of the component (ii) include various acrylic monomers such as acrylamides, acrylonitrile, acrylic acid or methacrylic acid and their esters, and monomers other than acrylic monomers such as hydrophobic monomers including vinyl aromatic compounds such as styrene and 2-vinylnaphthalene, and hydrophilic monomers such as vinyl sulfonic acid, (meth)allylsulfonic acid, vinyl carboxylate, and salts thereof. More specifically, examples of such acrylates include methyl methacrylate (MMA), n-butyl methacrylate (BMA), 2-hydroxyethyl methacrylate (HEMA), cyclohexyl methacrylate (CHMA, cyclohexyl methacrylate), 2-ethylhexyl acrylate (HA), acrylic acid (AA), 2,2,6,6-tetramethyl-4-piperidyl methacrylate (PMPMA, 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate), 2-(dimethylamino)ethyl acrylate (DMAEA, 2-(N,N-dimethylamino)ethyl acrylate), and N,N-dimethylaminoethyl methacrylate (DM, N,N-dimethylaminoethyl methacrylate).

[0021] (Combination Ratio) The blending ratio of component (i) to component (ii) described above is preferably 10:90 to 70:30 (weight ratio of component (i) to component (ii)), more preferably 20:80 to 60:40, and most preferably 30:70 to 50:50. Furthermore, the blending ratio of component (ii) to 100 parts by weight of component (i) is preferably 30 to 900 parts by weight, more preferably 50 to 400 parts by weight, and most preferably 100 to 250 parts by weight. If the amount of component (ii) is greater than this, the amount of component (i) is small, which may make it difficult to achieve both developer solubility and compatibility with organic solvents. If the amount of component (i) is less than this, compatibility with organic solvents tends to be reduced. The content of component (i) is preferably 10 to 70% by weight (units) of the entire copolymer, particularly preferably 20 to 60% by weight, and most preferably 30 to 50% by weight. If the amount is less than this, developer solubility tends to be reduced. If the amount is greater than this, compatibility with organic solvents tends to decrease. Furthermore, the molar ratio of component (i) to component (ii) described above is preferably 5 to 30 mol %, and particularly preferably 9 to 27 mol %, of the total of components (i) and (ii). This range provides an excellent balance of compatibility with organic solvents, solubility in the developer, and pigment dispersibility. Among the components (ii) described above, it is particularly preferable to use (ii-1) a compound having a (meth)acryloyl group but not an amino group, and (ii-2) a compound having a (meth)acryloyl group and an amino group in combination. Representative examples of compounds (ii-1) include methyl methacrylate (MMA), n-butyl methacrylate (BMA), 2-ethylhexyl acrylate (HA), acrylic acid (AA), and cyclohexyl methacrylate (CHMA). Representative examples of compounds (ii-2) include PMPMA, DM, and DMAEA. Compounds in which the amine moiety of DM or DMAEA is quaternized with benzyl chloride or the like can also be used. Among these, PMPMA and DM are particularly preferred. These are particularly suitable for use in forming copolymers that exhibit high performance, but the compounds that can be used in the present invention are not limited to these.

[0022] 2. Block Structure The block copolymer of the present invention can be obtained by polymerizing the above-mentioned compounds, and the block structure is not limited. However, to further enhance the effect, it is preferable to have the following multiple blocks: (a) a block in which only the compound (ii-1) is (co)polymerized, and (b) a block containing at least the compound (ii-2) and optionally the compound (ii-1). These blocks can be formed separately and then polymerized to form a block copolymer. In particular, it is preferable to have a structure in which the compound (ii-2) is introduced at the end of the block (b). In this way, the block containing the compound (ii-2) contributes to pigment adsorption, improving pigment dispersion. Furthermore, it is preferable to introduce the compound (i) described above into the block (a). In this way, the resulting photosensitive coloring composition has significantly improved developability while maintaining good rheological and optical properties. The mechanism is not entirely clear, but it is thought that the polyalkylene glycol portion of this compound is soluble in a wide range of polarities (from water to benzene), making it compatible with the organic solvent that serves as the dispersion medium, as well as with alkaline developers, thereby improving developability. One possible way to improve developability would be to increase the amount of acidic groups such as carboxyl groups that contribute to solubilization in alkaline developers, but in that case the acidic groups would react with sites on other molecules that are expected to adsorb the pigment, such as amines, weakening adsorption to the pigment and tending to reduce dispersibility; however, this phenomenon is less likely to occur in the case of polyalkylene glycols, which is thought to allow them to maintain good rheological and optical properties.

[0023] In the (a) block, it is preferable to copolymerize at least one of methyl methacrylate (MMA) and n-butyl methacrylate (BMA) together with the compound (i). The presence of these monomers allows for the production of a stable composition with high compatibility with the dispersion medium. It is also preferable to add a monomer having a hydroxyl group or a carboxyl group in addition to a (meth)acryloyl group, such as 2-hydroxyethyl methacrylate (HEMA, 2-hydroxyethyl methacrylate) or methacrylic acid (MAA). The ratio of the compound (i) to the other compounds in the (a) block is preferably 10 to 70 parts by weight, more preferably 20 to 60 parts by weight, and most preferably 30 to 50 parts by weight, of the other compounds per 100 parts by weight of the compound (i).

[0024] The (a) block is preferably 40 to 90% by weight, more preferably 20 to 85% by weight, and particularly preferably 50 to 80% by weight, based on the total weight of the copolymer of the present invention. If the content is below this range, developability and compatibility with organic solvents tend to decrease. On the other hand, if the content is above this range, pigment dispersibility tends to decrease.

[0025] Furthermore, the (a) block is preferably further divided into a block containing the compound (i) (hereinafter also referred to as the (a-1) block) and a block not containing the compound (i) (hereinafter also referred to as the (a-2) block). The ratio of the (a-1) block to the (a-2) block is preferably 20 to 40 parts by weight, and particularly preferably 10 to 50 parts by weight, per 100 parts by weight of the (a-1) block. The ratio of the compound (i) in the (a-1) block is preferably 40% by weight or more, more preferably 50% by weight or more, even more preferably 60% by weight or more, and most preferably 65% ​​by weight. As the ratio of the compound (i) in the (a-1) block decreases, dispersibility tends to decrease.

[0026] (Acid value) The acid value of the copolymer of the present invention is not limited, but is preferably 60 mgKOH / g, more preferably 40 mgKOH / g. Within this range, both dispersibility and developer solubility are particularly excellent. The acid value can be adjusted by adjusting the proportion of the above-mentioned various copolymerizable compounds having acidic groups.

[0027] (Method for Producing the Copolymer) The above-mentioned components (i) and (ii) may be copolymerized using known techniques. While the copolymerization method is not particularly limited, it is desirable to form the following blocks: As described above, the first block may be a portion containing component (i) (the aforementioned (a) block), and the second block may be a portion that adsorbs to the pigment (the aforementioned (b) block). Furthermore, a third block may be formed that has affinity for a dispersion medium, such as an organic solvent. The first block may be formed by polymerizing component (i) and other polymerizable monomers appropriately selected; the second block may be formed by polymerizing a monomer having a functional group that easily adsorbs to the pigment; and the third block may be formed by polymerizing primarily the above-mentioned polymerizable monomers that have affinity for the dispersion medium. The third block may also be the aforementioned (a-2) block. In this case, when forming the (a) block, it is preferable to form the aforementioned (a-2) block, then the (a-1) block, and then the (b) block. By doing so, the portion having affinity for a dispersant such as an organic solvent and the portion that easily adsorbs to the pigment can be separated, resulting in excellent pigment dispersibility. After each of the above blocks is formed, the block polymer can be produced by a known method. For example, the components that form the first block can be reacted in a reaction vessel, and then the components that form the second block can be added to the reaction vessel and reacted therewith, or the components that form the third block can be reacted, and then the monomers that form the first block can be added and reacted therewith, and then the components that form the second block can be added and reacted therewith. The second block is preferably positioned at the end of the copolymer by being formed first or last, and may further comprise multiple blocks.

[0028] In the present invention, in addition to the copolymers described above, conventionally known pigment dispersants may be added. Such dispersants are not particularly limited, but for example, mainly in organic solvent systems, polyurethane, carboxylic acid esters such as polyacrylate, unsaturated polyamides, polycarboxylic acid (partial) amine salts, polycarboxylic acid ammonium salts, polycarboxylic acid alkylamine salts, polysiloxanes, long-chain polyaminoamide phosphates, hydroxyl group-containing polycarboxylic acid esters, modified products thereof, amides formed by the reaction of poly(lower alkylene imine) with polyesters having free carboxylic acid groups, and salts thereof, etc. Among these, carboxylic acids such as polyacrylates or their esters, especially those having amines, are particularly preferred, but dispersants other than the copolymers of the present invention are not essential. A sufficient pigment dispersion effect can be obtained with just the copolymers of the present invention.

[0029] (Binder Resin) The pigment dispersion may also contain a binder resin typically contained in a photosensitive coloring composition. Examples of binder resins include phenolic resins, alkyd resins, polyester resins, amino resins, urea resins, melamine resins, guanamine resins, epoxy resins, styrene resins, vinyl resins, vinyl chloride resins, vinyl chloride / vinyl acetate copolymer resins, acrylic resins, polyurethane resins, silicone resins, polyamide resins, polyimide resins, rubber-based resins, cyclized rubbers, maleic oil-based resins, butyral-based resins, polybutadiene-based resins, cellulose-based resins, chlorinated polyethylene, and chlorinated polypropylene. These binder resins can be used alone or in combination of two or more. The binder resin can also be added when preparing the photosensitive coloring composition described below. The binder resin content is typically 5 to 90% by mass, preferably 10 to 80% by mass, and particularly preferably 20 to 50% by mass, of the solid content of the photosensitive coloring composition.

[0030] In addition, an alkali-soluble resin generally contained in a photosensitive coloring composition may be contained in the pigment dispersion. The alkali-soluble resin may also serve as a binder resin, or may be a different resin. As the alkali-soluble resin, those generally used in negative resists can be used, and any resin may be used as long as it is soluble in an alkaline aqueous solution used as a developer, and is not particularly limited. For example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, n-decyl (meth)acrylate, Examples of alkali-soluble resins include copolymers of one or more selected from the group consisting of (meth)acrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, vinylacetic acid, and anhydrides thereof, with one or more selected from the group consisting of (meth)acrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, vinylacetic acid, and anhydrides thereof. Examples also include polymers obtained by adding an ethylenically unsaturated compound having a glycidyl group or a hydroxyl group to the above copolymers. These alkali-soluble resins can also be added when preparing the pigment dispersion. The content of the alkali-soluble resin is typically 5 to 90% by mass, preferably 10 to 80% by mass, and particularly preferably 20 to 50% by mass, of the solids content of the photosensitive coloring composition. Furthermore, a portion of the alkali-soluble resin may be replaced with the binder resin described above.

[0031] (Pigment Derivatives) If necessary, known compounds such as pigment derivatives may also be added. These compounds act as intermediaries between the pigment and the dispersant, and are believed to improve dispersion stability by physically, electrically, or chemically adsorbing between the pigment surface and the dispersant. Examples of such pigment derivatives include pigment derivatives based on organic pigments such as diketopyrrolopyrroles, anthraquinones, phthalocyanines, metal phthalocyanines, quinacridones, azochelates, azos, isoindolinones, pyranthrones, indanthrones, anthrapyrimidines, dibromoanthanthrones, flavanthrones, perylenes, perinones, quinophthalones, thioindigo, and dioxazines, and which have been introduced with substituents such as hydroxyl groups, carboxyl groups, sulfonic acid groups, carbonamido groups, and sulfonamide groups. These pigments can be produced by sulfonating, sulfonamidating, or carboxylating them. Among these pigment derivatives, pigment derivatives obtained by sulfonating pigments are preferred from the viewpoint of dispersibility. These pigment derivatives and other compounds can be used alone or in combination of two or more. The content of the pigment derivative is preferably 1 to 40 parts by mass, more preferably 1 to 30 parts by mass, and even more preferably 3 to 20 parts by mass, per 100 parts by mass of the pigment.

[0032] (Preparation of Pigment Dispersion) The pigment dispersion of the present invention is prepared using the above-described components. The method for preparing the pigment dispersion is not particularly limited and any known method can be used. The dispersion method is not particularly limited, but the various finely divided or non-finely divided pigments described above may be added to a dispersion medium and dispersed. At this time, the copolymer of the present invention described above is present and dispersed.

[0033] The dispersing machine used for dispersion is not limited either, and may be media dispersion, in which the material to be treated is dispersed by vigorously stirring media made of glass, steel, stainless steel, ceramics, zircon, zirconia, or the like using a stirring mechanism such as a ball mill, bead mill, or sand mill, or medialess dispersion, in which a dispersing machine that does not use media is used, and any of these may be used without particular limitations.

[0034] (Photosensitive Coloring Composition and Its Production) The photosensitive coloring composition of the present invention can contain at least the copolymer of the present invention, pigment, dispersion medium, photopolymerizable monomer, and photopolymerization initiator described above. The photosensitive coloring composition of the present invention can be produced by using the pigment dispersion of the present invention described above and further blending other components to be added to the photosensitive coloring composition. Although the above components can be blended without previously preparing the pigment dispersion of the present invention, the performance of the photosensitive coloring composition can be further improved by previously preparing the pigment dispersion of the present invention containing at least the pigment and the copolymer of the present invention described above and dispersing the pigment finely and uniformly at that stage. Of the components in the photosensitive coloring composition, the binder resin and alkali-soluble resin described above can be used.

[0035] (Photopolymerizable Monomer) The photopolymerizable monomer is not particularly limited, but includes monofunctional monomers such as nonylphenyl carbitol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-ethylhexyl carbitol acrylate, 2-hydroxyethyl acrylate, and N-vinylpyrrolidone, as well as bifunctional monomers such as tripropylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, and bisphenol A diacrylate, trifunctional monomers such as trimethylolpropane triacrylate and pentaerythritol triacrylate, and other polyfunctional monomers such as dipentaerythritol pentaacrylate and hexaacrylate. Two or more of these photopolymerizable monomers can also be used. The amount of the photopolymerizable monomer is not particularly limited, but is preferably 10 to 80% by mass, particularly preferably 15 to 70% by mass, and even more preferably 20 to 60% by mass of the solids content of the photosensitive coloring composition.

[0036] (Photopolymerization Initiator) Examples of photopolymerization initiators include aromatic ketones, lophine dimers, benzoins, benzoin ethers, acetophenones, benzophenones, thioxanthones, ketals, quinones, triazines, imidazoles, oxime esters, phosphines, borates, carbazoles, titanocenes, and polyhalogens. For example, a combination of 4,4'-bis(diethylamino)benzophenone and 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 4-[p-N,N-di(ethoxycarbonylmethyl)-2,6-di(trichloromethyl)-s-triazine], and 2-methyl-4'-(methylthio)-2-morpholinopropiophenone are preferred. These photopolymerization initiators may be used alone, or two or more may be mixed in any ratio as needed.

[0037] The photosensitive coloring composition of the present invention may further contain additives such as a filler, an adhesion promoter, an antioxidant, an ultraviolet absorber, and a leveling agent.

[0038] [Color Filter] A color filter can be produced by applying the photosensitive coloring composition of the present invention described above to a substrate, photocuring, and developing it using a known method to obtain a coating film. For example, the photosensitive coloring composition is applied to a glass substrate or a silicon substrate using a roll coater, slit coater, spray, bar coater, applicator, spin coater, dip coater, inkjet, or screen printing. After application, the organic solvent is dried and, if necessary, heated. The heating temperature is preferably 50 to 140°C, more preferably 70 to 90°C. The heating time is preferably 0.5 to 60 minutes, more preferably 1 to 10 minutes. Photocuring involves irradiating the coating with ultraviolet light to harden the coating. In this case, a photomask that blocks ultraviolet light is placed over the areas to be removed in the subsequent development step, preventing hardening, thereby leaving a pattern on the glass substrate by development. Photocuring is carried out at an ultraviolet irradiation dose of 10 to 100 mJ / cm. ２It is preferable to carry out the development up to the final stage. For development, the photocured cured coating film is immersed in an alkaline aqueous solution as a developer, and then the uncured portions are removed by rinsing with water. The alkaline aqueous solution used preferably has an alkaline agent concentration of 0.001 to 10% by weight, and more preferably 0.01 to 1% by weight. Furthermore, the alkaline agent used for development is preferably an aqueous solution of ammonia, sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, triethylamine, triethanolamine, tetramethylammonium hydroxide, or the like.

[0039] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In addition, parts and percentages are by weight.

[0040] [Production of Micronized Pigment] 1. Production of Random Copolymer A SUS304 reactor was charged with 218.2 parts of propylene glycol monomethyl ether acetate, and the atmosphere inside the reactor was replaced with nitrogen. The internal temperature was raised to 100°C using an oil bath while stirring and mixing. Next, 0.4 parts of methyl methacrylate, 247.1 parts of dicyclopentanyl acrylate, 109.6 parts of methacrylic acid, 444.9 parts of propylene glycol monomethyl ether acetate, and 4.3 parts of azobisisobutyronitrile were added to a SUS304 dropping vessel and stirred and mixed. While maintaining the internal temperature of the reactor at 100°C, the solution was added dropwise from the dropping vessel to the reactor over 5 hours. After the dropwise addition, the mixture was kept at 100°C for 6 hours to complete the reaction, yielding a random copolymer.

[0041] 2. Pigment Micronization Treatment 94.0 parts by weight of CI Pigment Red 254 (DIC Corporation's "Irgazin Red 3670HD"), 1140.9 parts by weight of sodium chloride, 275.2 parts by weight of polyethylene glycol, and 55.3 parts by weight of the above random copolymer were placed in a 1 L kneader (manufactured by Toshin Corporation) and kneaded for 7 hours while adjusting the temperature inside the kneader to 35°C. The kneaded product was filtered, washed with water, dried, and pulverized to obtain a micronized pigment.

[0042] [Production of Block Copolymer] (Synthesis Example 1) A SUS304 reactor was charged with 121.5 parts of methyl methacrylate (MMA), 16.5 parts of S-benzyl-S-dodecyltrithiocarbonate, 3.8 parts of azobisisobutyronitrile, and 121.5 parts of propylene glycol monomethyl ether acetate, and the atmosphere inside the reactor was replaced with nitrogen. The internal temperature was raised to 70°C using an oil bath while stirring and mixing. After the temperature increase, the internal temperature was maintained for 6 hours. Next, 0.5 parts of methyl methacrylate (MMA), 79.9 parts of butyl methacrylate (BMA), 0.5 parts of 2-hydroxyethyl methacrylate (HEMA), 211.7 parts of methoxypolyethylene glycol (n = 9) methacrylate, 16.2 parts of methacrylic acid (MAA), and 110.2 parts of propylene glycol monomethyl ether acetate were added to a reaction vessel, and the atmosphere inside the vessel was replaced with nitrogen. The internal temperature was then raised to 70 ° C. while stirring and mixing. After the temperature increase, the internal temperature was maintained for 6 hours. Next, 106.9 parts of N,N-dimethylaminoethyl methacrylate (DM) and 128.3 parts of propylene glycol monomethyl ether acetate were added to a reaction vessel, and the atmosphere inside the vessel was replaced with nitrogen. The internal temperature was then raised to 70 ° C. while stirring and mixing. After the temperature increase, the internal temperature was maintained for 6 hours. Next, 0.5 parts of methyl methacrylate (MMA), 0.5 parts of cyclohexyl methacrylate (CHMA), 0.5 parts of 2-ethylhexyl acrylate (HA), 0.5 parts of acrylic acid (AA), and 0.5 parts of 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate (PMPMA) were added to a reaction vessel, and the atmosphere inside the vessel was replaced with nitrogen. The internal temperature was then raised to 70 ° C while stirring. After the temperature was raised, the reaction was continued for 2 hours to complete the polymerization. The pressure inside the reaction vessel was then reduced, the solvent was distilled off, and 810 parts of propylene glycol monomethyl ether acetate was added to obtain block copolymer (I).

[0043] Synthesis Example 2: A SUS304 reactor was charged with 42.0 parts of methyl methacrylate, 8.6 parts of S-benzyl-S-dodecyl trithiocarbonate, 2.0 parts of azobisisobutyronitrile, and 42.0 parts of propylene glycol monomethyl ether acetate. The atmosphere inside the reactor was replaced with nitrogen, and the internal temperature was raised to 70°C using an oil bath while stirring and mixing. After the temperature was raised, the internal temperature was maintained for 6 hours. Next, 0.3 parts of methyl methacrylate, 33.0 parts of butyl methacrylate, 0.3 parts of 2-hydroxyethyl methacrylate, 109.8 parts of methoxypolyethylene glycol (n = 9) methacrylate, 8.4 parts of methacrylic acid, and 62.3 parts of propylene glycol monomethyl ether acetate were added to the reactor. The atmosphere inside the reactor was replaced with nitrogen, and the internal temperature was raised to 70°C while stirring and mixing. After the temperature was raised, the internal temperature was maintained for 6 hours. Next, 0.3 parts of methyl methacrylate, 0.3 parts of cyclohexyl methacrylate, 0.3 parts of 2-ethylhexyl acrylate, 0.3 parts of acrylic acid, 84.8 parts of 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, and 175.7 parts of propylene glycol monomethyl ether acetate were added to a reaction vessel. The atmosphere inside the vessel was replaced with nitrogen, and the internal temperature was raised to 70°C while stirring and mixing. After the temperature was raised, the internal temperature was maintained for 6 hours. Next, 0.3 parts of N,N-dimethylaminoethyl methacrylate was added to the reaction vessel. The atmosphere inside the vessel was replaced with nitrogen, and the internal temperature was raised to 70°C while stirring and mixing. After the temperature was raised, the reaction was continued for 1 hour to complete the polymerization. The pressure inside the reaction vessel was then reduced, the solvent was distilled off, and 420 parts of propylene glycol monomethyl ether acetate was added to obtain block copolymer (II).

[0044] Synthesis Example 3: A SUS304 reactor was charged with 63.0 parts of methyl methacrylate, 8.6 parts of S-benzyl-S-dodecyl trithiocarbonate, 2.0 parts of azobisisobutyronitrile, and 63.0 parts of propylene glycol monomethyl ether acetate. The atmosphere inside the reactor was replaced with nitrogen, and the internal temperature was raised to 70°C using an oil bath while stirring and mixing. After the temperature was raised, the internal temperature was maintained for 6 hours. Next, 8.7 parts of methyl methacrylate, 41.4 parts of butyl methacrylate, 0.3 parts of 2-hydroxyethyl methacrylate, 109.8 parts of methoxypolyethylene glycol (n = 9) methacrylate, and 57.2 parts of propylene glycol monomethyl ether acetate were added to the reactor. The atmosphere inside the reactor was replaced with nitrogen, and the internal temperature was raised to 70°C while stirring and mixing. After the temperature was raised, the internal temperature was maintained for 6 hours. Next, 55.4 parts of N,N-dimethylaminoethyl methacrylate and 66.5 parts of propylene glycol monomethyl ether acetate were added to a reaction vessel. The atmosphere inside the vessel was replaced with nitrogen, and the internal temperature was raised to 70°C while stirring and mixing. After the temperature was raised, the internal temperature was maintained for 6 hours. Next, 0.3 parts of methyl methacrylate, 0.3 parts of cyclohexyl methacrylate, 0.3 parts of 2-ethylhexyl acrylate, 0.3 parts of acrylic acid, and 0.3 parts of 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate were added to the reaction vessel. The atmosphere inside the vessel was replaced with nitrogen, and the internal temperature was raised to 70°C while stirring and mixing. After the temperature was raised, the reaction was continued for 2 hours to complete the polymerization. The pressure inside the reaction vessel was then reduced, the solvent was distilled off, and 420 parts of propylene glycol monomethyl ether acetate was added to obtain block copolymer (III).

[0045] Synthesis Example 4: A SUS304 reactor was charged with 42.0 parts of methyl methacrylate, 8.6 parts of S-benzyl-S-dodecyl trithiocarbonate, 2.0 parts of azobisisobutyronitrile, and 42.0 parts of propylene glycol monomethyl ether acetate. The atmosphere inside the reactor was replaced with nitrogen, and the internal temperature was raised to 70°C using an oil bath while stirring and mixing. After the temperature was raised, the internal temperature was maintained for 6 hours. Next, 8.7 parts of methyl methacrylate, 33.0 parts of butyl methacrylate, 0.3 parts of 2-hydroxyethyl methacrylate, 109.8 parts of methoxypolyethylene glycol (n = 9) methacrylate, and 62.3 parts of propylene glycol monomethyl ether acetate were added to the reactor. The atmosphere inside the reactor was replaced with nitrogen, and the internal temperature was raised to 70°C while stirring and mixing. After the temperature was raised, the internal temperature was maintained for 6 hours. Next, 0.3 parts of methyl methacrylate, 0.3 parts of cyclohexyl methacrylate, 0.3 parts of 2-ethylhexyl acrylate, 0.3 parts of acrylic acid, 84.8 parts of 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, and 175.7 parts of propylene glycol monomethyl ether acetate were added to a reaction vessel. The atmosphere inside the vessel was replaced with nitrogen, and the internal temperature was raised to 70°C while stirring and mixing. After the temperature was raised, the internal temperature was maintained for 6 hours. Next, 0.3 parts of N,N-dimethylaminoethyl methacrylate was added to the reaction vessel. The atmosphere inside the vessel was replaced with nitrogen, and the internal temperature was raised to 70°C while stirring and mixing. After the temperature was raised, the reaction was continued for 1 hour to complete the polymerization. The pressure inside the reaction vessel was then reduced, the solvent was distilled off, and 420 parts of propylene glycol monomethyl ether acetate was added to obtain block copolymer (IV).

[0046] Synthesis Example 5: A SUS304 reactor was charged with 63.0 parts of methyl methacrylate, 8.6 parts of S-benzyl-S-dodecyl trithiocarbonate, 2.0 parts of azobisisobutyronitrile, and 63.0 parts of propylene glycol monomethyl ether acetate. The atmosphere inside the reactor was replaced with nitrogen, and the internal temperature was raised to 70°C using an oil bath while stirring and mixing. After the temperature was raised, the internal temperature was maintained for 6 hours. Next, 110.0 parts of methyl methacrylate, 41.4 parts of butyl methacrylate, 0.3 parts of 2-hydroxyethyl methacrylate, 8.4 parts of methacrylic acid, and 57.2 parts of propylene glycol monomethyl ether acetate were added to the reactor. The atmosphere inside the reactor was replaced with nitrogen, and the internal temperature was raised to 70°C while stirring and mixing. After the temperature was raised, the internal temperature was maintained for 6 hours. Next, 55.4 parts of N,N-dimethylaminoethyl methacrylate and 66.5 parts of propylene glycol monomethyl ether acetate were added to a reaction vessel. The atmosphere inside the vessel was replaced with nitrogen, and the internal temperature was raised to 70°C while stirring and mixing. After the temperature was raised, the internal temperature was maintained for 6 hours. Next, 0.3 parts of methyl methacrylate, 0.3 parts of cyclohexyl methacrylate, 0.3 parts of 2-ethylhexyl acrylate, 0.3 parts of acrylic acid, and 0.3 parts of 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate were added to the reaction vessel. The atmosphere inside the vessel was replaced with nitrogen, and the internal temperature was raised to 70°C while stirring and mixing. After the temperature was raised, the reaction was continued for 2 hours to complete the polymerization. The pressure inside the reaction vessel was then reduced, the solvent was distilled off, and 420 parts of propylene glycol monomethyl ether acetate was added to obtain block copolymer (V).

[0047] Synthesis Example 6: A SUS304 reactor was charged with 42.0 parts of methyl methacrylate, 8.6 parts of S-benzyl-S-dodecyl trithiocarbonate, 2.0 parts of azobisisobutyronitrile, and 42.0 parts of propylene glycol monomethyl ether acetate. The atmosphere inside the reactor was replaced with nitrogen, and the internal temperature was raised to 70°C using an oil bath while stirring and mixing. After the temperature was raised, the internal temperature was maintained for 6 hours. Next, 110.0 parts of methyl methacrylate, 33.0 parts of butyl methacrylate, 0.3 parts of 2-hydroxyethyl methacrylate, 8.4 parts of methacrylic acid, and 62.3 parts of propylene glycol monomethyl ether acetate were added to the reactor. The atmosphere inside the reactor was replaced with nitrogen, and the internal temperature was raised to 70°C while stirring and mixing. After the temperature was raised, the internal temperature was maintained for 6 hours. Next, 0.3 parts of methyl methacrylate, 0.3 parts of cyclohexyl methacrylate, 0.3 parts of 2-ethylhexyl acrylate, 0.3 parts of acrylic acid, 84.8 parts of 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, and 175.7 parts of propylene glycol monomethyl ether acetate were added to a reaction vessel. The atmosphere inside the vessel was replaced with nitrogen, and the internal temperature was raised to 70°C while stirring and mixing. After the temperature was raised, the internal temperature was maintained for 6 hours. Next, 0.3 parts of N,N-dimethylaminoethyl methacrylate was added to the reaction vessel. The atmosphere inside the vessel was replaced with nitrogen, and the internal temperature was raised to 70°C while stirring and mixing. After the temperature was raised, the reaction was continued for 1 hour to complete the polymerization. The pressure inside the reaction vessel was then reduced, the solvent was distilled off, and 420 parts of propylene glycol monomethyl ether acetate was added to obtain block copolymer (VI). The monomer compositions of the block copolymers obtained in the above synthesis examples are shown in Table 1.

[0048]

[0049] (Example 1) 1. Production of Pigment Dispersion Liquid 12.0 g of micronized pigment, 55.6 g of PGMEA, 10.0 g of PGME, 10.0 g of block copolymer (I), 11.4 g of "FOLET ZAH-110" (alkali-soluble resin manufactured by Soken Chemical & Engineering Co., Ltd.), and 1.0 g of PR254 sulfonate (sulfonic acid group 1-2) were mixed and stirred using ceramic beads (0.5 mm and 0.1 mm) in a paint shaker (manufactured by Asada Iron Works Co., Ltd.) for 11 hours to obtain a pigment dispersion liquid.

[0050] 2. Evaluation of Pigment Dispersion The following evaluation tests were carried out on the pigment dispersion. The results are shown in Table 3. (Viscosity) 1.2 ml of the dispersion was measured at 25°C for 60 seconds using an R-type viscometer (model: RE-215L, manufacturer: Toki Sangyo Co., Ltd.).

[0051] (Color Properties (sy, LY (Brightness))) 8.3 parts by weight of dispersion liquid was mixed with 1.9 parts by weight of resin ("Follet ZAH-110") (a 1:1 ratio of pigment to resin solids) to prepare the measurement ink. This measurement ink was applied to glass plates using a spin coater at approximately 600 rpm, 700 rpm, and 800 rpm and dried at 80°C. The color properties of the resulting coating film (hereinafter referred to as the "measurement coating film") were measured using a microspectrophotometer (model: LCF-1100MA, manufacturer: Otsuka Electronics Co., Ltd.). Based on the measured values ​​for these three coating films, the horizontal axis was plotted against the measured values ​​at 600 rpm, 700 rpm, and 800 rpm on the vertical axis. A calibration curve was then drawn to determine the value of x = 0.650, as shown in Table 3.

[0052] (Contrast) The contrast of the above coating film for measurement was measured using a contrast measurement device ("Contrast Tester CT-1 BSF" (BLANK=20,000) manufactured by Tsubosaka Electric Co., Ltd.). The results are shown in Table 3. (Film Thickness) Scratches were made in the above coating film for measurement with a cutter knife, and measurements were made using a non-contact surface / layer cross-sectional shape measurement system (model: VERTSCAN (registered trademark) R5300G, manufacturer: Nikon Instech Corporation).

[0053] 3. Preparation of photosensitive coloring composition 45.0 parts by weight of pigment dispersion, "Follet ZAH-110" (alkali-soluble resin manufactured by Soken Chemical Co., Ltd.) 12.4 parts by weight, dipentaerythritol hexaacrylate (hereinafter referred to as DPHA, a photopolymerizable compound) 3.3 parts by weight, "Irgacure OXE02" (2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, photopolymerization initiator manufactured by BASF Japan Co., Ltd.) 0.7 parts by weight, "BYK-330" (surface conditioner, manufactured by BYK Japan Co., Ltd.) 0.2 parts by weight, and 38.4 parts by weight of PGMEA were stirred and mixed until uniform, and then filtered through a 1.0 μm filter to obtain a photosensitive coloring composition.

[0054] 4. Evaluation of Photosensitive Coloring Compositions The photosensitive coloring compositions were subjected to a developer solubility evaluation test using the following method. (Preparation of Evaluation Coated Panels) The above photosensitive coloring composition was applied to soda glass using a bar coater #5. The photosensitive coloring composition obtained in Comparative Example 1, described below, was applied next to the composition as a reference, and the resulting composition was dried at 80°C for 5 minutes to prepare the evaluation coated panels. (Preparation of Developer) The developer was prepared as follows: 15 g of KOH, 25 g of Emulgen A60 (surfactant), and 460 g of ion-exchanged water were mixed to prepare a mixture. The mixture was added dropwise to 300 g of ion-exchanged water while measuring the conductivity. The developer was determined by stopping when the conductivity reached 0.4 mS / cm ±0.02. (Immersion of Evaluation Coated Panels in Developer and Evaluation) The developer was added to a disposable beaker "Descup 200 ml" manufactured by Teraoka Corporation, approximately one-third from the bottom, and the evaluation coated panels were immersed in the developer, standing them upright as shown in the schematic diagram in Figure 1. In the figure, 1 is a beaker, 2 is a coated plate for evaluation, and 3 is the developer. It was previously confirmed that the reference did not dissolve and after several tens of seconds the coating peeled off and floated from the plate, that if the coating did not dissolve, the coating peeled off and floated from the plate like the reference, that if the coating did not dissolve, it did not dissolve, and that if the coating did not dissolve, the liquid did not discolor. Therefore, dissolution of the coating can be confirmed by visually inspecting the coating or by the liquid being colored red. Based on this observation, if the coating dissolved, it is marked with an O, and if it did not dissolve and peeled, it is marked with an X, as shown in Table 3.

[0055] (Examples 2 to 4, Comparative Examples 1 and 2) Pigment dispersions were produced in the same manner as in Example 1, except that the block copolymers in Table 2 were used instead of block copolymer (I), and were evaluated in the same manner as in Example 1. The results are shown in Table 3. Photosensitive coloring compositions were also produced in the same manner as in Example 1, and were evaluated in the same manner as in Example 1. The results are shown in Table 3.

[0056] Comparative Example 3 A pigment dispersion was produced in the same manner as in Example 1, except that 58.9 parts by weight of PGMEA was used and 6.7 parts by weight of "BYK-LP 6919-1" (a polymer dispersant manufactured by BYK-Chemie) was used instead of 10.0 parts by weight of the block copolymer (I), and the pigment dispersion was evaluated in the same manner as in Example 1. The results are shown in Table 3. A photosensitive coloring composition was also produced in the same manner as in Example 1 and evaluated in the same manner as in Example 1. The results are shown in Table 3.

[0057]

[0058]

[0059] It can be seen that Examples 1 to 4, which contain the copolymer of the present invention, all maintain a good level of contrast, at 4000. It can also be seen that a relatively low viscosity is maintained. On the other hand, while Examples 1 to 4, which contain the copolymer of the present invention, all exhibit excellent developer solubility, Comparative Examples 1 to 3, which do not use the copolymer of the present invention, all exhibit poor developer solubility and peeled off. These results demonstrate that the present invention has solved the problem of achieving both contrast and viscosity and developer solubility, which was difficult with conventional technology. As such, the photosensitive coloring composition of the present invention has good developer solubility when used as a photosensitive coloring composition for color filters, and also has excellent optical properties such as high contrast. It can be seen that the pigment dispersion of the present invention can provide such a photosensitive coloring composition, and also has good liquid properties such as low viscosity, making it easy to handle.

[0060] According to the present invention, it is possible to obtain a pigment dispersion liquid and a photosensitive coloring composition which can solve the contradictory problems of maintaining low viscosity and high contrast while having good solubility in a developer.

[0061] 1 Beaker 2 Evaluation plate 3 Developer

Claims

1. A copolymer obtained by copolymerizing at least (i) 100 parts by weight of a compound represented by the following formula (I) and (ii) 30 to 900 parts by weight of a compound copolymerizable with the compound of formula (I). Formula (I) (In formula (I), R 1 and R 3 are hydrogen or an alkyl or alkoxy group having 1 to 4 carbon atoms, which may be different from each other; R 2 represents an alkyl group having 1 to 4 carbon atoms which may have a substituent, and n represents an integer of 4 to 15.

2. A pigment dispersion containing at least the copolymer according to claim 1, a pigment, and a dispersion medium.

3. A method for producing a photosensitive coloring composition, which comprises mixing a pigment dispersion containing at least the copolymer of claim 1, a pigment and a dispersion medium with at least a photopolymerizable monomer and a photopolymerization initiator.

4. A photosensitive coloring composition comprising at least the copolymer according to claim 1, a pigment, a dispersing medium, a photopolymerizable monomer, and a photopolymerization initiator.

Images