Black pigment dispersion composition for display, black pigment dispersion resist composition for display, and black resist film

Abstract

The invention provides a black pigment dispersion composition for a display, a black pigment dispersion resist composition for a display, and a black resist film. The black pigment dispersion composition for a display can form a coating film with excellent viscosity stability and excellent solvent resistance to solvents with high polarity such as N-methyl pyrrolidone. A black pigment dispersion composition for a display contains lactam black, a polymer pigment dispersant having a nitrogen atom, an acidic group-containing pigment dispersion aid, a first alkali-soluble resin, and a solvent.

Description

Technical Field

[0001] The present invention relates to a black pigment dispersion composition for displays, a black pigment dispersion resist composition for displays, and a black resist film. More specifically, the present invention relates to a black pigment dispersion composition for displays, a black pigment dispersion resist composition for displays, and a black resist film, each capable of forming a coating film that achieves both solvent resistance to highly polar solvents such as N-methylpyrrolidone and an excellent break point. Background Art

[0002] To improve the quality, contrast, and performance of liquid crystal displays, black matrices, black photo spacers, black columnar spacers, and black pigment dispersion compositions for displays used to construct them have been developed. Patent Document 1 discloses a black coloring composition that combines carbon black and lactam black, and further disperses a specific pigment using a pigment dispersant and a dispersing aid. Patent Document 2 discloses a black pigment dispersion composition that combines lactam black and carbon black, and blends specific violet, blue, and green pigments.

[0003] Prior art literature Patent Literature Patent Document 1: Japanese Patent No. 6914807 Patent Document 2: Japanese Patent No. 7080618 Summary of the Invention Problems to be solved by the invention The alignment film that makes up a display is formed by applying a solution of polyamic acid, a precursor of a polyimide resin, dissolved in a highly soluble alkaline solvent such as N-methylpyrrolidone (NMP). Therefore, areas in contact with the alignment film (such as the black matrix, black photospacers, and black columnar spacers) must be resistant to highly polar solvents like NMP. However, the pigment dispersion compositions described in Patent Documents 1 and 2 all have room for improvement in their resistance to solvents like NMP. Furthermore, the viscosity of these pigment dispersants tends to change over time, and there is also the issue of uneven development points.

[0004] The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a black pigment dispersion composition for displays, a black pigment dispersion resist composition for displays, and a black resist film that can form a coating film that can achieve both solvent resistance to highly polar solvents such as N-methylpyrrolidone and an excellent developing point.

[0005] Means used to solve problems The present inventors conducted intensive research to address the aforementioned issues and discovered that by combining lactam black, a polymeric pigment dispersant containing nitrogen atoms, an acidic group-containing pigment dispersing aid, an alkali-soluble resin, and a solvent, these issues can be simultaneously addressed. This led to the completion of the present invention. The present invention, which addresses the aforementioned issues, primarily has the following structure.

[0006] (1) A black pigment dispersion composition for a display, comprising lactam black, a polymer pigment dispersant having a nitrogen atom, a pigment dispersing aid containing an acidic group, a first alkali-soluble resin, and a solvent.

[0007] According to such a structure, the black pigment dispersion composition for displays can form a coating film that can achieve both solvent resistance to highly polar solvents such as N-methylpyrrolidone and an excellent development point.

[0008] (2) The black pigment dispersion composition for a display according to (1), wherein the pigment dispersing aid containing an acidic group is a pigment dispersing aid containing a sulfonic acid group, and the pigment dispersing aid containing a sulfonic acid group contains at least one of a sulfonate of Pigment Red 2, a sulfonate of Pigment Blue 15, a sulfonate of Pigment Yellow 138, and a sulfonate of Pigment Violet 23.

[0009] According to this structure, the black pigment dispersion composition for displays can form a coating film having even better solvent resistance to highly polar solvents such as N-methylpyrrolidone.

[0010] (3) A black pigment dispersion resist composition for displays, comprising the black pigment dispersion composition for displays according to (1) or (2), a second alkali-soluble resin containing an alkali-soluble resin having a crosslinkable functional group, a photopolymerizable compound, and a photopolymerization initiator.

[0011] With this structure, the black pigment dispersion resist composition for displays can form a coating film with improved solvent resistance to highly polar solvents such as N-methylpyrrolidone. Furthermore, the black pigment dispersion resist composition for displays exhibits excellent development adhesion even when forming thin lines, enabling the production of high-definition displays.

[0012] (4) A black resist film formed from the black pigment dispersion resist composition for displays described in (3).

[0013] With this structure, the black resist film has better resistance to highly polar solvents such as N-methylpyrrolidone. In addition, the black resist film has excellent development adhesion even when thin lines are formed, enabling a high-definition display.

[0014] Effects of the Invention The present invention can provide a black pigment dispersion composition for displays, a black pigment dispersion resist composition for displays, and a black resist film that can form a coating film having excellent viscosity stability and excellent solvent resistance to highly polar solvents such as N-methylpyrrolidone. DETAILED DESCRIPTION

[0015] Black pigment dispersion composition for displays A black pigment dispersion composition for displays (hereinafter referred to as a pigment dispersion composition) according to one embodiment of the present invention comprises lactam black, a polymeric pigment dispersant containing nitrogen atoms, an acidic group-containing pigment dispersing aid, a first alkali-soluble resin, and a solvent. Each of these components is described below.

[0016] (Lactam Black) The lactam black may be any known lactam black. As an example, the lactam black of this embodiment has the following main skeleton, more specifically Irgaphor Black S0100CF (manufactured by DIC Corporation). In the case of the following main skeleton, hydrogen atoms in the main skeleton may be appropriately replaced with low-molecular-weight functional groups (e.g., hydrocarbon groups such as alkyl, alkenyl, and alkynyl groups, acidic groups such as carboxyl, sulfonic, and phosphonic groups, basic groups such as amino groups, hydroxyl groups, etc.) or halogen atoms.

[0017] [Chemical Formula 1]

[0018] The volume-based particle size D50 value of the lactam black of this embodiment is preferably 70 nm or greater, more preferably 85 nm or greater. Furthermore, the D50 value is preferably 130 nm or less, more preferably 115 nm or less. By setting the D50 value within the above range, the pigment in the resulting pigment dispersion composition is less susceptible to sedimentation and exhibits excellent viscosity stability. Furthermore, the resulting resist film exhibits excellent linearity and roughness.

[0019] The volume-based particle size D90 value of lactam black is preferably 160 nm or greater, more preferably 180 nm or greater. Furthermore, the D90 value is preferably 300 nm or less, more preferably 280 nm or less. By setting the D90 value within the above range, the pigment in the resulting pigment dispersion composition is less susceptible to sedimentation and exhibits excellent viscosity stability. Furthermore, the resulting resist film exhibits excellent linearity and roughness.

[0020] In the present embodiment, the volume-based particle size can be measured by a laser diffraction particle size measurement method using NANOTRAC (UPA-EX150, manufactured by Nikkiso Co., Ltd.).

[0021] The content of lactam black is not particularly limited. For example, the content of lactam black in the pigment dispersion composition is preferably 3% by mass or greater, more preferably 5% by mass or greater. Furthermore, the content of lactam black in the pigment dispersion composition is preferably 25% by mass or less, more preferably 20% by mass or less. By adjusting the lactam black content within the above range, the pigment dispersion composition can provide a resist film having a good OD value and good development adhesion.

[0022] (Polymer pigment dispersant containing nitrogen atoms) There are no particular limitations on the polymeric pigment dispersant containing nitrogen atoms. For example, a polymeric pigment dispersant containing nitrogen atoms may include a nitrogen-containing graft copolymer, a nitrogen-containing acrylic block copolymer containing a functional group such as a tertiary amine group, a quaternary ammonium salt group, or a nitrogen-containing heterocycle in a side chain, or a urethane polymeric dispersant. Among these, a nitrogen-containing graft copolymer is preferably used as the polymeric pigment dispersant. This facilitates the production of a high-definition, long-life display with a pigment dispersion composition.

[0023] The main chain of the nitrogen-containing graft copolymer may be linear or branched.

[0024] The amine value of the nitrogen-containing graft copolymer is preferably 60 mgKOH / g or less, more preferably 40 mgKOH / g or less. When the amine value is within the above range, the viscosity stability of the pigment dispersion composition is further improved.

[0025] Commercially available products of the nitrogen-containing graft copolymer include LPN21324 (manufactured by BYK), ESLEAM AD-374M, and ESLEAM AD-3172M.

[0026] Urethane dispersants can be obtained by reacting a compound having one or more hydroxyl groups in its molecule and a number average molecular weight of 300 to 10,000, and a compound having a basic group in its molecule and a functional group reactive with an isocyanate group, with the isocyanate groups of a polyisocyanate compound. This urethane dispersant can be obtained by, for example, the method described in Japanese Patent Application Laid-Open No. 60-166318.

[0027] The polyisocyanate compound constituting the urethane dispersant may include an isocyanate compound having two or more isocyanate groups. For example, the isocyanate compound having two or more isocyanate groups is an aromatic diisocyanate compound such as 2,4-toluene diisocyanate, a dimer of 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, p-xylene diisocyanate, m-xylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate; hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate (4,4'-methylenebis[1,1'-diisocyanate]), 4,4'-diisocyanate, ... Aliphatic or alicyclic polyisocyanates such as cyclohexylisocyanate, methylcyclohexane-2,4 (or 2,6) diisocyanate, and 1,3-(isocyanatomethyl)cyclohexane; polyisocyanates having an isocyanuric group based on a diisocyanate (such as polyisocyanates having an isocyanuric group formed by trimerization of a diisocyanate), polyisocyanates obtained by reacting a diisocyanate with a polyol, and polyisocyanates obtained by the biuret reaction of a diisocyanate compound. Preferred polyisocyanate compounds include polyisocyanates having an isocyanuric group based on a diisocyanate, such as toluene diisocyanate and isophorone diisocyanate.

[0028] The compound having one or more hydroxyl groups in the molecule constituting the urethane-based dispersant is a polyether compound, a polyester compound, or the like.

[0029] The above-mentioned polyether compounds include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, polybutylene glycol, and polytetramethylene glycol; alkylene glycols such as ethylene glycol, propane diol (Propanediol), propylene glycol, tetramethylene glycol, pentamethylene glycol, hexane diol, neopentyl glycol, glycerol, trimethylolpropane, pentaerythritol, diglycerol, di(trimethylolpropane), and dipentaerythritol; and ethylene oxide-modified products, propylene oxide-modified products, butylene oxide-modified products, and tetrahydrofuran-modified products of low molecular weight monohydric alcohols such as methanol and ethanol.

[0030] The polyester compounds are, for example, alkylene glycols such as ethylene glycol, propane diol, propylene glycol, tetramethylene glycol, pentamethylene glycol, hexane diol, neopentyl glycol, glycerol, trimethylolpropane, pentaerythritol, diglycerol, di(trimethylolpropane), dipentaerythritol; ε-caprolactone-modified products, γ-butyrolactone-modified products, δ-valerolactone-modified products, methylvalerolactone-modified products of low molecular weight monohydric alcohols such as methanol and ethanol; esters of aliphatic dicarboxylic acids such as adipic acid or dimer acid with polyols such as neopentyl glycol or methylpentanediol, i.e., aliphatic polyesters. Ester polyols; polyester polyols such as aromatic polyester polyols, which are esters of aromatic dicarboxylic acids such as terephthalic acid and polyols such as neopentyl glycol; esters of polyhydroxy compounds such as polycarbonate polyols, acrylic polyols, and polytetramethylene hexaglycerol ether (tetrahydrofuran-modified hexaglycerol) with dicarboxylic acids such as fumaric acid, phthalic acid, isophthalic acid, itaconic acid, adipic acid, sebacic acid, and maleic acid; and polyhydroxy compounds such as monoglycerides obtained by transesterification of polyhydroxy compounds such as glycerol with fatty acid esters. Compounds having one or more hydroxy groups in the molecule are preferably ε-caprolactone adducts of alcohols.

[0031] The number average molecular weight of the compound having one or more hydroxyl groups in the molecule is preferably 300 to 10,000, more preferably 300 to 6,000. The number average molecular weight can be measured by column chromatography.

[0032] The basic compound containing a functional group reactive with an isocyanate group within the molecule of the urethane dispersant is not particularly limited. For example, the basic compound containing a functional group reactive with an isocyanate group within the molecule of the urethane dispersant is at least one compound selected from the group consisting of polyols, polythiols, and amines having an N,N-disubstituted amino group or a heterocyclic nitrogen atom. These compounds have a Zerevitinoff-active hydrogen atom and at least one basic group containing a nitrogen atom. Such compounds include N,N-dimethyl-1,3-propanediamine, N,N-diethyl-1,4-butanediamine, 2-dimethylethanolamine, 1-(2-aminoethyl)-piperazine, 2-(1-pyrrolidinyl)-ethylamine, 4-amino-2-methoxypyrimidine, 4-(2-aminoethyl)-pyridine, 1-(2-hydroxyethyl)-piperazine, 4-(2-hydroxyethyl)-morpholine, 2-mercaptopyrimidine, 2-mercaptobenzimidazole, 2-amino-6-methoxybenzothiazole, N,N-diallylmelamine, 3-amino-1,2,4-triazole, 1-(2-hydroxyethyl)-imidazole, and 3-mercapto-1,2,4-triazole. Amines having a heterocyclic nitrogen atom are preferred.

[0033] The reaction in the synthesis of the urethane dispersant is not particularly limited. Furthermore, the amine value of the urethane dispersant is preferably greater than 0 mgKOH / g and not greater than 40 mgKOH / g.

[0034] Commercially available products of urethane dispersants include Disperbyk (registered trademark)-161 (amine value 11 mgKOH / g, manufactured by BYK), Disperbyk (registered trademark)-162 (amine value 13 mgKOH / g, manufactured by BYK), Disperbyk (registered trademark)-167 (amine value 13 mgKOH / g, manufactured by BYK), Disperbyk (registered trademark)-182 (amine value 13 mgKOH / g, manufactured by BYK), Disperbyk (registered trademark)-2163 (amine value 10 mgKOH / g, manufactured by BYK), and Disperbyk (registered trademark)-2164 (amine value 14 mgKOH / g, manufactured by BYK).

[0035] Returning to the overall description of the polymeric pigment dispersant containing nitrogen atoms, the weight average molecular weight of the polymeric pigment dispersant containing nitrogen atoms, as measured by GPC, in terms of polystyrene, is preferably 3,000 or greater, more preferably 5,000 or greater. Furthermore, the weight average molecular weight of the polymeric pigment dispersant containing nitrogen atoms is preferably 100,000 or less, more preferably 50,000 or less. By setting the weight average molecular weight within the above range, the pigment dispersion composition exhibits excellent viscosity stability.

[0036] The content of the polymeric pigment dispersant containing nitrogen atoms is not particularly limited. For example, the content of the polymeric pigment dispersant containing nitrogen atoms in the pigment dispersion composition is preferably 1.0% by mass or greater, and more preferably 3.0% by mass or greater. Furthermore, the content of the polymeric pigment dispersant containing nitrogen atoms in the pigment dispersion composition is preferably 8.0% by mass or less, and more preferably 6.0% by mass or less. By adjusting the content of the polymeric pigment dispersant containing nitrogen atoms within the above range, the pigment dispersion composition exhibits excellent viscosity stability and solvent resistance.

[0037] (Pigment dispersing aid containing an acidic group) The pigment dispersion composition of the present embodiment contains an acidic group-containing pigment dispersing aid for the purpose of improving the dispersibility of the pigment.

[0038] There are no particular limitations on the acidic group-containing pigment dispersing aid. For example, examples of acidic group-containing pigment dispersing aids include perylene compounds, diketopyrrolopyrrole compounds, azonaphthol compounds, dioxazine compounds, quinacridone compounds, phthalocyanine compounds and their metal complexes, compounds containing acidic groups such as carboxyl groups and sulfonic acid groups introduced into pigments such as anthraquinone, naphthalene, acridone, or triazine (pigment derivatives containing acidic groups), and compounds obtained by neutralizing these pigments with organic amines. Among these, the acidic group-containing pigment dispersing aid preferably includes a sulfonic acid group-containing pigment dispersing aid. This allows the pigment dispersion composition to form a coating film with improved solvent resistance to highly polar solvents such as N-methylpyrrolidone.

[0039] The sulfonic acid group-containing pigment dispersing aid preferably contains at least one of a sulfonate of Pigment Red 2, a sulfonate of Pigment Blue 15, a sulfonate of Pigment Yellow 138, or a sulfonate of Pigment Violet 23. This allows the pigment dispersion composition to form a coating film having even better resistance to highly polar solvents such as N-methylpyrrolidone.

[0040] The content of the acidic group-containing pigment dispersing aid is preferably 1.0 parts by mass or greater, and more preferably 1.5 parts by mass or greater, per 100 parts by mass of lactam black. Furthermore, the content of the acidic group-containing pigment dispersing aid is preferably 5.0 parts by mass or less, and more preferably 4.0 parts by mass or less, per 100 parts by mass of lactam black. This allows the pigment dispersion composition to form a coating film having even greater resistance to highly polar solvents such as N-methylpyrrolidone.

[0041] (First alkali-soluble resin) The first alkali-soluble resin is formulated, for example, to form a color filter partition wall pattern when used in a black matrix. Alternatively, the first alkali-soluble resin is formulated to form a color filter partition wall pattern and a liquid crystal layer spacer when used in black photospacers and black columnar spacers.

[0042] The first alkali-soluble resin is not particularly limited. If an example is given, it is an acrylic copolymer resin, a maleic acid copolymer resin, a polyester resin obtained by polycondensation reaction, an epoxy acrylate resin obtained by the polyaddition reaction of acrylic acid and an epoxy compound, a urethane acrylate resin obtained by the polymerization reaction of acrylic acid, a polyol and an isocyanate compound, etc. Thus, for the pigment dispersion composition, it is easy to obtain a high-precision display. Among them, the first alkali-soluble resin is preferably an acrylic copolymer resin or an epoxy acrylate resin from the viewpoint of excellent developability and developer adhesion.

[0043] The first alkali-soluble resin is not particularly limited. For example, the first alkali-soluble resin is a resin containing an anionic group such as a carboxyl group, a sulfonic acid group, or a phosphonic acid group (—P(═O)(OH 2 )).

[0044] The acrylic resin is not particularly limited, but examples thereof include the "Follett" series, ZAH-106, ZAH-110, ZAH-115, and ZAH-310 manufactured by Soken Chemical Co., Ltd.

[0045] The epoxy acrylate resin is not particularly limited. For example, examples of epoxy acrylate resins include the "KAYARAD" series, CCR-1291H, CCR-1235, ZAR-1035, ZAR-2000, ZFR-1401H, ZFR-1491H, ZCR-1569H, ZCR-1601H, ZCR-1797H, ZCR-1798H, UXE-3000, and UXE-3024 manufactured by Nippon Kayaku Co., Ltd.

[0046] The urethane acrylate resin is not particularly limited. For example, urethane acrylate resins include the "KAYARAD" series, UX-3204, UX-4101, UXT-6100, UX-8101, UX-0937, DPHA-40H, and UX-5000 manufactured by Nippon Kayaku Co., Ltd.

[0047] The acid value of the first alkali-soluble resin is preferably 10 mgKOH / g or more, more preferably 20 mgKOH / g or more, from the viewpoint of alkali developability, and preferably 300 mgKOH / g or less, more preferably 200 mgKOH / g or less.

[0048] The weight-average molecular weight of the first alkali-soluble resin is preferably 1,000 or greater, and more preferably 3,000 or greater, from the perspective of film formation properties for resist films, etc. Furthermore, the weight-average molecular weight of the alkali-soluble resin is preferably 100,000 or less, and more preferably 50,000 or less, from the perspective of improving solubility. The weight-average molecular weight can be measured by gel permeation chromatography (GPC). As an example, using a Waters 2690 (manufactured by Waters) as a GPC apparatus and a PLgel 5μ MIXED-D (manufactured by Polymer Laboratories) as a column, chromatography is performed under the conditions of tetrahydrofuran as the developing solvent, a column temperature of 25°C, a flow rate of 1 ml / min, an RI detector, a sample injection concentration of 10 mg / ml, and an injection volume of 100 μL. This allows the weight-average molecular weight in terms of polystyrene to be determined.

[0049] The content of the first alkali-soluble resin is not particularly limited. For example, the content of the first alkali-soluble resin is preferably 5 parts by mass or greater, and more preferably 10 parts by mass or greater, per 100 parts by mass of lactam black. Furthermore, the content of the first alkali-soluble resin is preferably 90 parts by mass or less, and more preferably 80 parts by mass or less, per 100 parts by mass of lactam black. By adjusting the content of the first alkali-soluble resin within the above range, the pigment dispersion composition facilitates the production of high-definition displays.

[0050] (Solvent) The pigment dispersion composition of this embodiment contains a solvent. The solvent is not particularly limited. As an example, from the perspective of being able to stably disperse lactam black and fully dissolve the first alkali-soluble resin, etc., the solvent is preferably an ester solvent, an ether solvent, an ether-ester solvent, a ketone solvent, an aromatic hydrocarbon solvent, a nitrogen-containing solvent, or the like.

[0051] The ester solvents include methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, 3-methyl-3-methoxybutyl propionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl ethoxyacetate, glycolate, n-pentyl formate, and the like.

[0052] The ether solvents include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, and the like.

[0053] Ether ester solvents include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and the like.

[0054] Ketone solvents include methyl isobutyl ketone, cyclohexanone, 2-heptanone, δ-butyrolactone, etc.

[0055] Aromatic hydrocarbon solvents include toluene, xylene, alkylnaphthalene and the like.

[0056] Nitrogen-containing solvents include N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, and the like.

[0057] When a solvent is present, the solvent content is not particularly limited. For example, the solvent content is preferably 40% by mass or greater, and more preferably 50% by mass or greater, in the pigment dispersion composition. Furthermore, the solvent content is preferably 90% by mass or less, and more preferably 80% by mass or less, in the pigment dispersion composition. By ensuring that the solvent content is within this range, the pigment dispersion composition exhibits excellent dispersion stability of lactam black.

[0058] Returning to the overall description of the pigment dispersion composition, the method for preparing the pigment dispersion composition of this embodiment is not particularly limited. As an example, the pigment dispersion composition can be prepared by mixing various materials and grinding them overnight using a bead mill or the like.

[0059] As described above, the pigment dispersion composition of this embodiment can form a coating film with excellent viscosity stability and excellent solvent resistance to highly polar solvents such as N-methylpyrrolidone. Therefore, the pigment dispersion composition is suitable for use in displays, and is particularly suitable for use as a black matrix, black photospacer, black columnar spacer, etc. Specifically, when used for black matrices, black photospacers, and black columnar spacers, the pigment dispersion composition of this embodiment is less likely to cause malfunction of the display, and degradation can be suppressed.

[0060] <Black pigment dispersion resist composition for displays> A black pigment dispersion resist composition for displays (hereinafter also referred to as a resist composition) according to one embodiment of the present invention comprises the aforementioned black pigment dispersion composition for displays, a second alkali-soluble resin, a photopolymerizable compound, and a photopolymerization initiator. The second alkali-soluble resin may be the same as the first alkali-soluble resin. The second alkali-soluble resin preferably comprises an alkali-soluble resin having a crosslinkable functional group. Each of these is described below.

[0061] (Black pigment dispersion composition for displays) Since the black pigment dispersion composition for displays (hereinafter also referred to as a pigment dispersion composition) is as described above, the description thereof will be omitted as appropriate.

[0062] The content of the pigment dispersion composition is not particularly limited. As an example, the content of the pigment dispersion composition is preferably 20% by mass or more, more preferably 30% by mass or more. In addition, the content of the pigment dispersion composition is preferably 60% by mass or less, more preferably 50% by mass or less. By setting the content of the pigment dispersion composition within the above range, the resist composition can easily achieve both development adhesion and OD value.

[0063] (First alkali-soluble resin) Since the first alkali-soluble resin is the same as described above, its description is omitted.

[0064] (Second alkali-soluble resin) The second alkali-soluble resin is formulated to improve developability and solvent resistance using an alkaline developer. The second alkali-soluble resin is not particularly limited as long as it has crosslinked functional groups. For example, the second alkali-soluble resin is an alkali-soluble resin associated with the pigment dispersion composition and having crosslinked functional groups in the first alkali-soluble resin. Specifically, the second alkali-soluble resin is preferably an epoxy acrylate resin, an epoxy resin, an acrylic resin, or a urethane resin, with an epoxy acrylate resin being more preferred.

[0065] The content of the second alkali-soluble resin is not particularly limited. As an example, the content of the second alkali-soluble resin in the resist composition is preferably 3% by mass or more, more preferably 5% by mass or more. Furthermore, the content of the second alkali-soluble resin in the resist composition is preferably 15% by mass or less, more preferably 12% by mass or less. By setting the content of the second alkali-soluble resin within the above range, the developability of the resist composition with an alkaline developer is within an appropriate range.

[0066] (Photopolymerizable compound) The photopolymerizable compound is not particularly limited, but as an example, a photopolymerizable compound is a monomer, oligomer, or the like having a photopolymerizable unsaturated bond.

[0067] The monomers having one photopolymerizable unsaturated bond are: alkyl methacrylates or alkyl acrylates such as methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, methyl acrylate, butyl acrylate, 2-ethylhexyl acrylate; aryl methacrylates or aryl acrylates such as benzyl methacrylate and benzyl acrylate; alkoxyalkyl methacrylates or alkoxyalkyl acrylates such as butoxyethyl methacrylate and butoxyethyl acrylate; N,N-dimethylaminoethyl methacrylate and N,N-dimethylaminoethyl acrylate. Aminoalkyl methacrylates or aminoalkyl acrylates such as methylaminoethyl ester; methacrylates or acrylates of polyalkylene glycol monoalkyl ethers such as diethylene glycol monoethyl ether, triethylene glycol monobutyl ether, and dipropylene glycol monomethyl ether; methacrylates or acrylates of polyalkylene glycol monoaryl ethers such as hexaethylene glycol monophenyl ether; isobornyl methacrylate or isobornyl acrylate; glycerol methacrylate or glycerol acrylate; 2-hydroxyethyl methacrylate or 2-hydroxyethyl acrylate, etc.

[0068] Monomers with two or more photopolymerizable unsaturated bonds are: bisphenol A dimethacrylate, 1,4-butanediol dimethacrylate, 1,3-butanediol dimethacrylate, diethylene glycol dimethacrylate, glycerol dimethacrylate, neopentyl glycol dimethacrylate, polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol tetramethacrylate, dipentaerythritol tetramethacrylate, dipentaerythritol tetramethacrylate, dipentaerythritol di ... Pentaerythritol hexamethacrylate, dipentaerythritol pentamethacrylate, bisphenol A diacrylate, 1,4-butanediol diacrylate, 1,3-butanediol diacrylate, diethylene glycol diacrylate, glycerol diacrylate, neopentyl glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, tetraethylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate, etc.

[0069] The oligomer having a photopolymerizable unsaturated bond is an oligomer obtained by appropriately polymerizing the above-mentioned monomers.

[0070] The content of the photopolymerizable compound is not particularly limited. For example, the content of the photopolymerizable compound in the resist composition is preferably 1% by mass or greater, and more preferably 2.5% by mass or greater. Furthermore, the content of the photopolymerizable compound in the resist composition is preferably 15% by mass or less, and more preferably 10% by mass or less. By setting the content of the photopolymerizable compound within the above range, the resist composition can easily achieve both curability and alkali developability of the resist film.

[0071] (Photopolymerization initiator) The photopolymerization initiator is not particularly limited. For example, the photopolymerization initiator includes benzophenone, N,N'-tetraethyl-4,4'-diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, benzyl, 2,2-diethoxyacetophenone, benzoin, benzoin methyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, α-hydroxyisobutylbenzophenone, thioxanthone, 2-chlorothioxanthone, 1-hydroxycyclohexyl phenyl ketone, tert-butylanthraquinone, 1-chloroanthraquinone, 2,3-dichloroanthraquinone, 3-chloro-2-methylanthraquinone, 2-ethylanthraquinone, 1,4-naphthoquinone, 1,2-benzanthraquinone, 1,4-dimethylanthraquinone, 2-phenylanthraquinone, triazine-based photopolymerization initiators, and oxime ester-based photopolymerization initiators.

[0072] The content of the photopolymerization initiator is not particularly limited. For example, the content of the photopolymerization initiator in the resist composition is preferably 0.1% by mass or greater, more preferably 0.3% by mass or greater. Furthermore, the content of the photopolymerization initiator in the resist composition is preferably 5% by mass or less, more preferably 2% by mass or less. By setting the content of the photopolymerization initiator within the above range, the resist composition can easily achieve both the curability of the resist film and the adhesion to fine lines.

[0073] Furthermore, additives such as a leveling agent, an antioxidant, and a defoaming agent may be added to the resist composition as needed.

[0074] The method for preparing the resist composition of the present embodiment is not particularly limited. As an example, the resist composition can be prepared by co-dispersing various materials using a stirring device or the like.

[0075] The resist composition of this embodiment exhibits excellent viscosity stability. Furthermore, the resist composition can suppress a decrease in OD (optical density) during the waiting period between resist application to a substrate and pre-baking. The resulting resist film has low reflectivity and excellent development adhesion, enabling the production of high-definition displays.

[0076] <Black resist film> A black resist film according to one embodiment of the present invention is a black resist film formed from the above-mentioned black pigment dispersion resist composition for displays.

[0077] The method for forming the black resist film is not particularly limited. As an example, the black resist film can be obtained by using the above-mentioned black pigment dispersion resist composition for display, using a known method. Specifically, the black resist film can be formed into a black matrix in the following manner, that is, the above-mentioned resist composition is applied to a transparent substrate, dried to form a coating film, and then a photomask is placed on the coating film, and the black matrix is ​​formed by image exposure, development, and photocuring as needed via the photomask.

[0078] The substrate is not particularly limited, and can be, for example, a glass substrate, a silicon substrate, a polycarbonate substrate, a polyester substrate, a polyamide substrate, a polyamideimide substrate, a polyimide substrate, an aluminum substrate, a printed circuit substrate, an array substrate, or the like.

[0079] As the method of applying, drying, exposing, and developing the resist composition, a known method can be appropriately selected.

[0080] As an example, the coating method of the resist composition is screen printing, roller coating, curtain coating, spray coating, spin coating, etc. In addition, after the resist composition is applied, it can also be heated by using a heating method such as a circulation oven, infrared heater, hot plate, etc. as needed to volatilize the solvent contained in the resin layer. The heating conditions can be appropriately set according to the composition of the resist composition used. Generally, the heating conditions are 30 seconds to 30 minutes at a temperature of 50°C to 120°C.

[0081] The thickness of the coating film (after drying) is not particularly limited. For example, the coating film thickness is preferably 0.2 to 10 μm, more preferably 0.5 to 6 μm, and even more preferably 1 to 4 μm. By setting the coating film thickness within this range, the resulting black matrix can be easily developed in a desired pattern and exhibits a desired optical density.

[0082] The exposure method is not particularly limited. For example, the exposure method is irradiation with active energy rays such as ultraviolet rays or excimer lasers. The energy dose can be appropriately set according to the composition of the resist composition. For example, the energy dose is 30 to 2000 mJ / cm 2 The light source used for exposure is not particularly limited. For example, the light source is a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, a xenon lamp, a metal halide lamp, or the like.

[0083] The alkaline developer used for development is not particularly limited. Examples include aqueous solutions of sodium carbonate, potassium carbonate, calcium carbonate, sodium hydroxide, potassium hydroxide, and the like; aqueous solutions of amine compounds such as ethylamine, diethylamine, and dimethylethanolamine; and aqueous solutions of p-phenylenediamine compounds such as tetramethylammonium, 3-methyl-4-amino-N,N-diethylaniline, 3-methyl-4-amino-N-ethyl-N-β-hydroxyethylaniline, 3-methyl-4-amino-N-ethyl-N-β-methanesulfonamidoethylaniline, 3-methyl-4-amino-N-ethyl-N-β-methoxyethylaniline, and their sulfates, hydrochlorides, or p-toluenesulfonates. Furthermore, defoaming agents and surfactants may be added to the alkaline developer as needed.

[0084] After alkali development, post-baking can accelerate the curing of the resin. The post-baking conditions are not particularly limited. As an example, the post-baking conditions are 80°C to 250°C for 10 minutes to 4 hours.

[0085] As described above, the black resist film of the present embodiment can be obtained using a resist composition containing the above-mentioned pigment dispersion composition. Therefore, the black resist film has excellent solvent resistance to highly polar solvents such as N-methylpyrrolidone. In addition, the black resist film has excellent development adhesion even when fine lines are formed, which can obtain a high-definition display. Therefore, the black resist film is suitable for use in image display devices or touch panels using high-definition displays.

[0086] [Example] The present invention will be described in more detail below by way of examples. The present invention is not limited to these examples. In addition, unless otherwise specified, "%" means "mass %" and "parts" means "mass parts."

[0087] The raw materials used are as follows.

[0088] <Lactam Black> Irgaphor BLACK: S0100CF: (manufactured by DIC Corporation) <Polymer pigment dispersants containing nitrogen atoms> LPN21324: (BYK Corporation), nitrogen-containing graft copolymer (quaternary ammonium group-containing random copolymer), amine value 0 mgKOH / g, solid content 40% by mass LPN6919: (BYK Corporation), nitrogen-containing block copolymer (tertiary amino group-containing block copolymer), amine value 120 mgKOH / g, solid content 60% by mass <Acidic pigment dispersing aids> PR2 sulfonate: (manufactured by our company) (Method for producing PR2 sulfonate) 30 ml of concentrated sulfuric acid was added to a 100 ml Erlenmeyer flask. 10 g of CI Pigment Red 2 was added while stirring with a magnetic stirrer and stirred at room temperature for 30 minutes. A mixture of 50 g of water and 50 g of ice was placed in a 1 L beaker. The reaction mixture was poured into the ice water and stirred with a magnetic stirrer for 30 minutes. The solid was filtered under reduced pressure, washed with water, and dried to produce a sulfonic acid group-containing pigment dispersing aid (a sulfonated form of CI Pigment Red 2).

[0089] P.Y138 sulfonate: (manufactured by our company) (P.Y138 Method for producing sulfonated products) To a 100ml Erlenmeyer flask, 20ml of concentrated sulfuric acid was added. 10g of Pigment Yellow 138 and 20ml of 28% fuming sulfuric acid were added while stirring with a magnetic stirrer. The mixture was stirred at 100-110°C for 240 minutes. A mixture of 50g of water and 50g of ice was placed in a 1L beaker. The reaction mixture was poured into the ice water and stirred with a magnetic stirrer for 30 minutes. The solid was filtered under reduced pressure, washed with water, and dried to yield 11g of the target sulfonic acid group-containing pigment dispersing aid (P.Y138 sulfonate).

[0090] Solsperse 5000S (PB15 sulfonate): (manufactured by Japan Lubrizol Corporation) Solsperse 12000J (PB15 sulfonate): (manufactured by Japan Lubrizol Corporation) PV23 sulfonate: (manufactured by our company) (Method for producing PV23 sulfonate) A sulfonic acid group-containing pigment dispersing aid (sulfonate of CI Pigment Violet 238) was prepared by replacing CI Pigment 2 in the method for producing a sulfonate of PR2 with CI Pigment Violet 23.

[0091] <First alkali-soluble resin> ZAH-110: (Soken Chemical Co., Ltd.), alkali-soluble acrylic resin, Follett ZAH-110, acid value 100 mgKOH / g, weight average molecular weight approximately 15,000, solid content 35% by mass <Second alkali-soluble resin> ZCR-1569H: (Nippon Kayaku Co., Ltd.), alkali-soluble epoxy acrylate resin, KAYARAD ZCR-1569H, acid value 98 mgKOH / g, weight average molecular weight approximately 4,500, solid content 70% by mass <Photopolymerizable compounds> DPHA: Dipentaerythritol hexaacrylate <Photopolymerization initiator> Irgacure OXE02: (manufactured by BASF Japan Co., Ltd.), oxime ester-based photopolymerization initiator, Irgacure OXE02 Surface Modifiers MF-554: (DIC Corporation), MEGAFACE F-554, fluorine-containing and lipophilic oligomer, solid content 100% Solvents PGME: Propylene glycol monomethyl ether PGMEA: Propylene glycol monomethyl ether acetate <Preparation of Black Pigment Dispersion Composition for Displays> (Preparation Examples 1 to 7, Comparative Preparation Example 1) Various materials were mixed to obtain the compositions shown in Table 1 (in terms of solid content, expressed in mass %), and milled overnight using a bead mill to prepare black pigment dispersion compositions for displays according to Preparation Examples 1 to 7 and Comparative Preparation Example 1.

[0092] [Table 1]

[0093] <Examples 1 to 7, Comparative Example 1> (Black pigment dispersion resist composition for displays) Various materials were mixed to obtain the compositions shown in Table 2 (unit: mass %), uniformly mixed using a high-speed stirrer, and then filtered through a filter with a pore size of 3 μm to obtain black pigment dispersion resist compositions for displays of Examples 1 to 7 and Comparative Example 1.

[0094] The resulting black pigment-dispersed resist composition for displays was used to evaluate the change in optical density (OD value), development point, development adhesion, viscosity stability, and solvent resistance by the following methods. The results are shown in Table 2.

[0095] OD value (optical density) Each display black pigment-dispersed resist composition was applied to a glass substrate (Eagle XG, manufactured by Corning) using a spin coater to a film thickness of 1 μm. After pre-baking at 100°C for 3 minutes, the film was exposed using a high-pressure mercury lamp and post-baked at 230°C for 30 minutes, resulting in a black resist pattern formed only in the solid areas. The optical density (OD) of each solid black resist pattern was measured using a transmission densitometer (Ihac-T5, manufactured by Ihara Electronics Co., Ltd.). The OD values ​​were measured at eight locations and corrected for film thickness and pigment concentration. The average OD value, excluding the maximum and minimum values, was used as the optical density. The coated film was then scraped off with a cutter, and the film thickness at the OD measurement points was measured.

[0096] Corrected OD value = measured OD value × 15.0 / pigment concentration × 1.0 / measured film thickness value The corrected OD value was 1.2 or above and was considered acceptable.

[0097] <Development Point and Development Adhesion> The black pigment-dispersed resist composition for displays prepared in each example and comparative example was applied to a glass substrate (EAGLE XG) using a spin coater to a film thickness of 3.5 μm and pre-baked at 100°C for 3 minutes. Next, a photomask having a line pattern with line widths ranging from 1 μm to 100 μm was used, and a high-pressure mercury lamp was used with a UV cumulative dose of 50 mJ / cm 2 Afterwards, the film was exposed to light at 1 kgf / cm2 in a 0.05% potassium hydroxide aqueous solution at 23°C. 2 The time when the development pattern begins to appear under pressure spray bath development is taken as the development point. In the evaluation of development adhesion, development is completed when the time reaches 1.5 times the development point. 2 The glass substrate was cleaned with pressure spray water and the minimum line pattern size (μm) remaining on the glass substrate was evaluated. The minimum line pattern size of 20μm or less was considered acceptable.

[0098] <Viscosity stability> The black pigment dispersion compositions for displays produced in each of the Examples and Comparative Examples were placed in sealed glass bottles and stored at 60°C for one week. The viscosity at 25°C was measured before and after storage using an E-type viscometer (Toki Sangyo Co., Ltd., Model RE100L). The viscosity change rate was determined and evaluated according to the following criteria.

[0099] Viscosity change rate = [(viscosity after 1 week storage - viscosity before storage) / (viscosity before storage)] ・Evaluation criteria ○: The viscosity change rate is 10% or less.

[0100] △: The viscosity change rate exceeds 10% and is below 20%.

[0101] ×: The viscosity change rate exceeded 20%.

[0102] Solvent resistance The black pigment-dispersed resist composition for displays produced in each example and comparative example was applied to a glass substrate (50 mm x 70 mm) using a spin coater to a film thickness of 3.5 μm. The film was pre-baked at 100°C for 2 minutes, exposed using a high-pressure mercury lamp, and post-baked at 230°C for 20 minutes, resulting in a black resist pattern consisting solely of solid areas. The substrate was cut into 50 mm x 10 mm pieces to produce test pieces. 20 mL of N-methylpyrrolidone (NMP) was added to a screw-type flask and heated to 80°C. The test piece was placed in the screw-type flask and placed in an oven at 80°C for 40 minutes. The test piece was then removed from the screw-type flask to obtain an eluent. The absorbance of the eluent was measured using a spectrophotometer (UV-2500PC), and the average absorbance from 300 to 1000 nm was recorded as the result. Smaller values ​​are considered better.

[0103] [Table 2]

[0104] As shown in Tables 1 and 2, the pigment dispersion compositions of Preparation Examples 1 to 8 and the resist compositions of Examples 1 to 7 using these compositions of the present invention achieve both excellent solvent resistance and excellent developing point. Furthermore, the resist compositions achieve high OD values. Furthermore, the resulting resist films exhibit excellent developing adhesion.

Claims

1. A black pigment dispersion composition for display, characterized in that The invention contains lactam black, a polymer pigment dispersant having nitrogen atoms, a pigment dispersing aid containing an acidic group, a first alkali-soluble resin and a solvent.

2. The black pigment dispersion composition for display according to claim 1, wherein The pigment dispersing aid containing an acidic group is a pigment dispersing aid containing a sulfonic acid group, The sulfonic acid group-containing pigment dispersing aid contains at least any one of a sulfonate of Pigment Red 2, a sulfonate of Pigment Blue 15, a sulfonate of Pigment Yellow 138, and a sulfonate of Pigment Violet 23.

3. A black pigment dispersion resist composition for display, characterized in that ， Contains the black pigment dispersion composition for display according to claim 1 or 2, a second alkali-soluble resin, a photopolymerizable compound, and a photopolymerization initiator, The second alkali-soluble resin includes an alkali-soluble resin having a cross-linked functional group.

4. A black resist film, characterized in that It is formed from the black pigment dispersion resist composition for displays according to claim 3.

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