Black dispersion, UV-curable black composition, resin composition, black matrix for color filters, CMOS camera module

Abstract

To provide a black fluid dispersion in which black pigment is less likely to flocculate even after storage in the air for a long period of time, an ultraviolet curable black composition including the black fluid dispersion, and a resin composition obtained by curing the ultraviolet curable black composition.SOLUTION: A black fluid dispersion contains a solvent, a black pigment, and a polymer dispersion agent, wherein the solvent includes either or both of a monofunctional monomer and a bifunctional monomer having an ethylenically unsaturated bond, the black pigment includes zirconium nitride, the polymer dispersion agent has a main chain, and a plurality of side chains coupled to the main chain, the main chain is polyalkyleneimine, and each of the plurality of side chains includes a comb-type polymer which is a group containing an oxyethylene group and an oxypropylene group.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a black dispersion, an ultraviolet-curable black composition, a resin composition, a black matrix for a color filter, and a CMOS camera module. [Background technology]

[0002] Insulating black pigments are used, for example, as black matrices for color filters in displays, light-shielding materials in CMOS camera modules, and optical adhesives. Dispersions containing black pigments are also used as materials for forming black patterns, such as black resists and black inks for inkjet printing. Known black resists include ultraviolet-curable black compositions containing an insulating black pigment and an ultraviolet-curable organic material.

[0003] A known ultraviolet-curable black composition uses zirconium nitride particles as an insulating black pigment and an acrylic monomer or an epoxy monomer as an ultraviolet-curable organic material. It is also known to add a dispersant or a plasticizer to the ultraviolet-curable black composition. Known dispersants include polymer dispersants with molecular weights ranging from several thousand to several tens of thousands, each containing a secondary amine, tertiary amine, carboxylic acid, phosphoric acid, or phosphate ester as a functional group that adsorbs to the insulating black pigment (Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-38119 Summary of the Invention [Problem to be solved by the invention]

[0005] In the ultraviolet-curable black composition, it is preferable that the black pigment be uniformly dispersed. For this reason, ultraviolet-curable black compositions are generally produced by dispersing the black pigment in a dispersion medium to prepare a uniform black dispersion, and then mixing the black dispersion with an ultraviolet-curable organic material. However, the degree of oxidation (degree of nitridation) of the particle surface of zirconium nitride particles used as an insulating black pigment may change due to moisture or the atmosphere. For this reason, when a black dispersion in which zirconium nitride particles are dispersed is stored in the atmosphere for a long period of time, the surface of the zirconium nitride particles changes, reducing the affinity between the zirconium nitride particles and the dispersant, and the zirconium nitride particles may become detached from the dispersant and aggregate.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a black dispersion in which black particles are resistant to aggregation even when stored in air for a long period of time, an ultraviolet-curable black composition containing the black dispersion, and a resin composition obtained by curing the ultraviolet-curable black composition. A further aim of the present invention is to provide a black matrix for a color filter and a CMOS camera module that use the ultraviolet-curable black composition. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the black dispersion of the present invention contains a solvent, a black pigment, and a polymer dispersant, wherein the solvent contains a (meth)acrylic monofunctional monomer and a bifunctional monomer each having a (meth)acryloyl group, and the black pigment contains zirconium nitride, The polymer dispersant includes a comb polymer having a main chain and a plurality of side chains bonded to the main chain, the main chain being a polyalkyleneimine, and each of the plurality of side chains being a group containing an oxyethylene group and an oxypropylene group, and the comb polymer is a polymer represented by the following general formula (I): -(-CH2-CH2-N(-R)-)n- (I) In the general formula (I), R represents a group containing an oxyethylene group and an oxypropylene group, and n represents a number of 5 to 30.

[0008] In the black dispersion liquid having the above-described configuration, the main chain of the polymeric dispersant is a polyalkyleneimine, which provides extremely high affinity with the zirconium nitride contained in the black pigment. Therefore, even if the surface of the black particles dispersed in the solvent changes, the black particles and the polymeric dispersant are unlikely to separate. Furthermore, the polymeric dispersant is a comb polymer with multiple side chains that contain oxyethylene and oxypropylene groups, which provides high affinity with the solvent, which is a monofunctional monomer and a bifunctional monomer having an ethylenically unsaturated bond. Therefore, in the curable black composition having the above-described configuration, the black particles are stably dispersed in the solvent and are unlikely to aggregate even when stored in the atmosphere for a long period of time.

[0009] Here, in the black dispersion of the present invention, the comb polymer may be a polymer represented by the following general formula (I).

[0012] Also, The comb polymer has a polyethyleneimine main chain and contains many nitrogen atoms, which have a high affinity for zirconium nitride, which increases the affinity between the comb polymer and zirconium nitride. This makes it more difficult for the black particles to separate from the polymer dispersant, resulting in more stable dispersion of the black particles in the solvent and less tendency for the black particles to aggregate.

[0013] In the black dispersion of the present invention, the solvent may further contain an organic substance that does not have an ethylenically unsaturated bond. In this case, it becomes possible to adjust the physical properties such as the viscosity and surface tension of the black dispersion liquid by using an organic substance that does not have an ethylenically unsaturated bond, thereby widening the range of applications of the black dispersion liquid.

[0014] The ultraviolet-curable black composition of the present invention contains the above-mentioned black dispersion, an ultraviolet-curable organic substance, and an ultraviolet curing agent. According to the ultraviolet-curable black composition of the present invention, since it contains the above-mentioned black dispersion, the black particles are stably dispersed and are less likely to aggregate even when stored in the atmosphere for a long period of time. Furthermore, since it contains an ultraviolet-curable organic material and an ultraviolet curing agent, it can be cured by irradiation with ultraviolet light. Furthermore, since the monofunctional monomer and bifunctional monomer contained as the solvent have an ethylenically unsaturated bond, when the ultraviolet-curable black composition is cured, they are incorporated into the cured product of the ultraviolet-curable organic material, making it possible to omit or simplify the drying process after curing.

[0015] Here, in the ultraviolet-curable black composition of the present invention, the ultraviolet-curable organic material may be an oligomer having an ethylenically unsaturated bond or a polyfunctional monomer having two or more ethylenically unsaturated bonds. In this case, since the ultraviolet-curable organic material is an oligomer or a polyfunctional monomer, it can be easily cured by irradiation with ultraviolet light.

[0016] The ultraviolet-curable black composition of the present invention may be configured as a black resist. In this case, since the black particles are stably dispersed in the ultraviolet-curable black composition, a uniform black pattern can be formed.

[0017] The resin composition of the present invention is a cured product of the above-mentioned ultraviolet-curable black composition. Since the resin composition having the above-mentioned configuration is a cured product of the above-mentioned ultraviolet-curable black composition, the black particles are less likely to form secondary particles (aggregated particles) and are uniformly dispersed, thereby providing the resin composition with uniform visible light blocking properties.

[0018] The black matrix for a color filter of the present invention contains a cured product of the above-described ultraviolet-curable black composition. The black matrix for a color filter having the above-described configuration contains a cured product of the above-described ultraviolet-curable black composition, and therefore has uniform visible light blocking properties. As a result, liquid crystal displays and organic EL displays using the above-described black matrix for a color filter have improved visible light contrast.

[0019] The CMOS camera module of the present invention has a light-shielding material containing a cured product of the above-described ultraviolet-curable black composition. The CMOS camera module having the above configuration has a light-blocking material containing the cured product of the ultraviolet-curable black composition, which enhances the ability to block unwanted visible light, thereby providing a digital camera using the CMOS camera module with the above configuration with high sensitivity. [Effects of the Invention]

[0020] According to the present invention, it is possible to provide a black dispersion in which black particles are resistant to aggregation even when stored in the atmosphere for a long period of time, an ultraviolet-curable black composition containing the black dispersion, and a resin composition obtained by curing the ultraviolet-curable black composition. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, a black dispersion, an ultraviolet-curable black composition, a resin composition, a black matrix for a color filter, and a CMOS camera module according to one embodiment of the present invention will be described.

[0022] [Black dispersion] The black dispersion of this embodiment contains a solvent, a black pigment, and a polymer dispersant. The solvent contains one or both of a monofunctional monomer having an ethylenically unsaturated bond and a bifunctional monomer. Examples of the monofunctional monomer and bifunctional monomer having an ethylenically unsaturated bond that can be used include a (meth)acrylic monofunctional monomer and bifunctional monomer having a (meth)acryloyl group, and a vinyl monofunctional monomer having a vinyl group. Examples of acrylic monofunctional monomers include (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, isoamyl acrylate, tetrahydrofurfuryl (meth)acrylate, and isobornyl (meth)acrylate. Examples of acrylic bifunctional monomers include 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, ethylene oxide-modified bisphenol A di(meth)acrylate, neopentyl triethylene glycol di(meth)acrylate, etc. Examples of vinyl monofunctional monomers include vinyl chloride, vinyl acetate, etc.

[0023] As a solvent, an organic substance having no ethylenically unsaturated bond may be added. Examples of the solvent having no ethylenically unsaturated bond include glycol ethers such as ethyl carbitol, ethyl carbitol acetate, butyl carbitol acetate (BCA), butyl carbitol, methyl cellosolve, ethyl cellosolve, diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monomethyl ether, and triethylene glycol monoethyl ether, α-terpineol, methyl ethyl ketone (MEK), ethyl acetate, butyl acetate, n-propanol, isopropanol, methanol, ethanol, and toluene.

[0024] When a solvent having no ethylenically unsaturated bond is used, the content thereof is preferably in the range of 1 part by mass to 60 parts by mass, relative to 100 parts by mass of the total amount of the monofunctional monomer and bifunctional monomer having an ethylenically unsaturated bond. By ensuring that the content of the solvent having no ethylenically unsaturated bond is within this range, physical properties such as the viscosity and surface tension of the black dispersion liquid can be adjusted. The content of the solvent having no ethylenically unsaturated bond is more preferably in the range of 5 parts by mass to 50 parts by mass, and particularly preferably in the range of 10 parts by mass to 40 parts by mass.

[0025] The black pigment is dispersed as black particles in a solvent. The black pigment contains zirconium nitride. The black particles contained in the black pigment preferably contain 80 mass % or more, more preferably 90 mass % or more, of zirconium nitride. The black particles may be zirconium nitride particles. The zirconium nitride particles may contain oxygen. Furthermore, the zirconium nitride particles may contain a metal element other than zirconium.

[0026] The average particle diameter of the black pigment may be 500 nm or less. The average particle diameter of the black pigment is more preferably in the range of 10 nm or more and 400 nm or less, and particularly preferably in the range of 10 nm or more and 300 nm or less. The average particle diameter of the black pigment is the BET diameter calculated from the BET specific surface area and density measured by the BET method, assuming that the particles are spherical, using the following formula (1): where L is the average particle diameter (m) of the black pigment, and ρ is the true density (g / m) of the black pigment. 3 ), S is the specific surface area of ​​the black pigment (m 2 / g). The BET specific surface area can be measured by the BET single-point method using nitrogen adsorption, using, for example, a specific surface area measuring device (SA-1100, manufactured by Shibata Scientific Co., Ltd.). L = 6 / (ρ × S) (1)

[0027] The black pigment can be produced, for example, by using a method (thermit process) in which zirconium oxide powder is reduced by reacting it with nitrogen gas in the presence of a reduction catalyst. For example, metallic magnesium powder can be used as the reduction catalyst. Magnesium oxide powder may be added to the metallic magnesium powder. Zirconium nitride particles produced using metallic magnesium as the reduction catalyst contain magnesium as an inevitable impurity. The magnesium content of the zirconium nitride particles may be in the range of 0.1% by mass to 5.0% by mass.

[0028] The black pigment can also be produced by reducing zirconium metal particles or zirconium oxide particles in a nitrogen gas atmosphere using a plasma nanoparticle production device (plasma synthesis method). By using this plasma synthesis method, high-purity zirconium nitride particles can be obtained.

[0029] The content of the black pigment in the black dispersion is preferably in the range of 5% by mass to 50% by mass. By keeping the content of the black pigment within this range, the black pigment can be stably dispersed. The content of the black pigment is more preferably in the range of 5% by mass to 45% by mass, and particularly preferably in the range of 10% by mass to 40% by mass.

[0030] The polymeric dispersant includes a comb polymer having a main chain and a plurality of side chains attached to the main chain. The main chain is a polyalkyleneimine. The polyalkyleneimine of the main chain is composed of repeating units of an imino group and an alkylene group. The number of carbon atoms in the alkylene group may be in the range of 2 to 6. The polyalkyleneimine may be linear or branched. The hydrogen atoms of the imino groups are bonded to the terminal alkylamino groups (-R 1 NH2:R 1 The alkylamino group may be substituted with an alkyl group having 2 to 6 carbon atoms, and the hydrogen atom of the amino group of the alkylamino group may be further substituted with an alkylamino group. The hydrogen atom of the alkyl group of the alkylamino group may be substituted with a group containing an oxyethylene group and an oxypropylene group. Each of the multiple side chains is a group containing an oxyethylene group and an oxypropylene group. The number of oxyethylene groups contained in each side chain may be in the range of 1 to 20, and the number of oxypropylene groups may be in the range of 1 to 20. Multiple oxyethylene groups and oxypropylene groups may each form a block copolymer. The main chain of the comb polymer is bonded to zirconium nitride contained in the black particles, and the side chain of the comb polymer is bonded to a monofunctional monomer having an ethylenically unsaturated bond contained in the solvent. The number average molecular weight (Mn) of the polymer dispersant determined by gel permeation chromatography (GPC) measurement may be in the range of 500 to 10,000.

[0031] The comb polymer may be a polymer represented by the following general formula (I):

[0032] [ka]

[0033] In the general formula (I), n represents a number of 5 to 30. In general formula (I), represents a single bond or a divalent linking group. The divalent linking group may be an oxygen atom (-O-), a carbonyl group (-CO-), an alkylene group having 1 to 8 carbon atoms, or a group combining two or more of these groups. The alkylene group may or may not have a substituent. An example of the substituent is an alkyl group having 1 to 3 carbon atoms. As a group combining two or more groups, a group combining an oxygen atom and an alkylene group, or a group combining an oxygen atom, a carbonyl group, and an alkylene group can be used. Examples of a group combining an oxygen atom and an alkylene group include * 1 -O-Alkylene group -O-* 2 (* 1 represents a bond bonding to a carbon atom of the polyalkyleneimine, and * 2 represents a bond bonded to R). An example of a group combining an oxygen atom, a carbonyl group, and an alkylene group is -* 1 -O-CO-Alkylene group -CO-O-* 2 (* 1 represents a bond bonding to a carbon atom of the polyalkyleneimine, and * 2 represents the bond that bonds to R).

[0034] In general formula (I), R is a group containing an oxyethylene group and an oxypropylene group. R may be a group represented by the following general formula (II) or (III). -(PO) p -(EO) q -X···(II) -(PO) r -(EO) s -(PO) t -(EO) u -X···(III)

[0035] In general formulas (II) and (III), PO represents an oxypropylene group, and EO represents an oxyethylene group. X represents a hydrogen atom or a methyl group. In general formula (II), p and q represent any number from 1 to 20. In general formula (III), r, s, t, and u each represent any number from 1 to 10.

[0036] The content of the polymer dispersant in the black dispersion is preferably in the range of 1 to 50 parts by mass per 100 parts by mass of the black pigment. By keeping the content of the polymer dispersant within this range, the dispersibility of the black pigment can be improved. The content of the polymer dispersant is more preferably in the range of 2 to 45 parts by mass, and particularly preferably in the range of 5 to 40 parts by mass.

[0037] The black dispersion may contain other additives. Examples of the other additives include surfactants, rheology control agents such as plasticizers and leveling agents, and a combination of these may be used. The black dispersion may also contain a polymerization inhibitor to suppress polymerization of the monofunctional monomer and the bifunctional monomer.

[0038] The black dispersion can be produced, for example, by mixing a solvent, a black pigment, and a polymer dispersant, and dispersing the resulting mixture. Examples of the dispersion treatment device that can be used include a bead mill and an ultrasonic disperser.

[0039] In the black dispersion of this embodiment configured as described above, the main chain of the polymer dispersant is a polyalkyleneimine, which provides extremely high affinity with the zirconium nitride contained in the black pigment. Therefore, even if the surface of the black particles dispersed in the solvent changes, the black particles and the polymer dispersant are unlikely to separate. Furthermore, the polymer dispersant is a comb polymer with multiple side chains that contain oxyethylene and oxypropylene groups, providing high affinity with the solvent, which is a monofunctional monomer having one ethylenically unsaturated bond. Therefore, in the curable black composition of this embodiment, the black particles are stably dispersed in the solvent and are unlikely to aggregate even when stored in air for long periods of time.

[0040] Furthermore, in the black dispersion of this embodiment, when the comb polymer is a polymer represented by the general formula (I) above, the comb polymer has a main chain of polyethyleneimine and contains many nitrogen atoms, which have a high affinity for zirconium nitride, so that the affinity between the comb polymer and the black particles is higher. As a result, the black particles are less likely to separate from the polymer dispersant, the black particles are more stably dispersed in the solvent, and the black particles are less likely to aggregate.

[0041] Furthermore, in the black dispersion of this embodiment, an organic substance having no ethylenically unsaturated bond may be further added as a solvent to adjust the physical properties of the black dispersion, such as the viscosity and surface tension, thereby broadening the range of application of the black dispersion.

[0042] [Ultraviolet curable black composition] The ultraviolet-curable black composition of this embodiment includes the above-described black dispersion, an ultraviolet-curable organic material, and an ultraviolet curing agent. That is, the ultraviolet-curable black composition includes a solvent, a black pigment, a polymer dispersant, an ultraviolet-curable organic material, and an ultraviolet curing agent. The content of the black pigment in the ultraviolet-curable black composition is, for example, in the range of 0.1% by mass to 60% by mass.

[0043] Examples of UV-curable organic materials that can be used include oligomers having an ethylenically unsaturated bond or polyfunctional monomers having three or more ethylenically unsaturated bonds. The oligomer having an ethylenically unsaturated bond may be an acrylic oligomer having two or more (meth)acryloyl groups. The acrylic oligomer is a low-molecular-weight polymer formed by polymerization of an acrylic monofunctional monomer. Examples of acrylic oligomers include acrylic (meth)acrylate, urethane (meth)acrylate, epoxy (meth)acrylate, and polyester (meth)acrylate. The molecular weight of the acrylic oligomer may be, for example, in the range of 1,000 to 10,000 in number average molecular weight. These (meth)acrylate monomers and oligomers can be used alone or in combination of two or more. The acrylic oligomer is not limited to those described above, and commonly available oligomers can be used. The polyfunctional monomer having an ethylenically unsaturated bond may be an acrylic polyfunctional monomer having three or more (meth)acryloyl groups. Examples of the acrylic polyfunctional monomer include pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and trimethylolpropane tri(meth)acrylate. The content of the ultraviolet-curable organic material is, for example, in the range of 5 parts by mass to 99 parts by mass relative to 100 parts by mass of the ultraviolet-curable black composition.

[0044] The ultraviolet-curable black composition may contain other ultraviolet-curable organic materials. Examples of the other ultraviolet-curable organic materials include styrene-based monomers and cationically curable monomers. Examples of the styrene-based monomers include styrene, vinyltoluene, and divinylbenzene. Examples of the cationically curable monomers include oxetane.

[0045] The ultraviolet curing agent is preferably a compound that can absorb ultraviolet light, specifically light with a wavelength of 100 to 400 nm, and initiate a polymerization reaction. The ultraviolet curing agent may be, for example, a radical generator or a photoacid generator. Examples of the ultraviolet curing agent include acetophenone-based compounds, benzophenone-based compounds, benzoin ether-based compounds, triazine compounds, phosphine oxide-based compounds, sulfonium-based compounds, and organic peroxides. Examples of the acetophenone-based compounds include acetophenone, dimethylacetophenone, and 2-hydroxy-2-methylpropiophenone. Examples of the benzophenone-based compounds include benzophenone and 2-chlorobenzophenone. Examples of the benzoin ether-based compounds include benzoin and benzoin methyl ether. Examples of the phosphine oxide-based compounds include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide. Examples of sulfonium compounds include bis(4-tert-butylphenyl)iodonium hexafluorophosphate, triphenylsulfonium tetrafluoroborate, and tri-p-tolylsulfonium trifluoromethanesulfonate. Examples of organic peroxides include benzoyl peroxide and cumene peroxide. The content of the ultraviolet curing agent is, for example, in the range of 0.5 parts by mass to 15 parts by mass with respect to 100 parts by mass of the ultraviolet curing organic material.

[0046] The UV-curable black composition may contain a plasticizer. Examples of plasticizers include phosphate ester-based plasticizers, phthalate ester-based plasticizers, aliphatic-basic ester-based plasticizers, aliphatic dibasic acid ester-based plasticizers, dihydric alcohol ester-based plasticizers, and oxyacid ester-based plasticizers. Examples of phosphate ester-based plasticizers include tributyl phosphate and 2-ethylhexyl phosphate. Examples of phthalate ester-based plasticizers include dimethyl phthalate and dibutyl phthalate. Examples of aliphatic-basic ester-based plasticizers include butyl oleate and glycerin monooleate. Examples of aliphatic dibasic acid ester-based plasticizers include dibutyl adipate and di-2-ethylhexyl sebacate. Examples of dihydric alcohol ester-based plasticizers include diethylene glycol dibenzoate and triethylene glycol di-2-ethyl butyrate. Examples of the oxyacid ester plasticizer include methyl acetylricinoleate and tributyl acetylcitrate. When a plasticizer is used, the content thereof is, for example, in the range of 1 part by mass to 100 parts by mass relative to 100 parts by mass of the ultraviolet-curable organic material.

[0047] The ultraviolet-curable black composition may contain a polymerization inhibitor to improve storage stability. Examples of polymerization inhibitors include phenol derivatives such as hydroquinone, hydroquinone monomethyl ether, and t-butylphenol, benzoquinone derivatives such as benzoquinone and 2-methyl-1,4-benzoquinone, nitro compounds such as dinitrobenzene and nitrophenol, nitroso compounds such as nitrosobenzene, phenothiazine, and phenyl-t-butylnitrone, iron(III) chloride, and sulfur. These polymerization inhibitors may be used alone or in combination of two or more. When a polymerization inhibitor is used, the content thereof may be within a range that does not inhibit curing when the ultraviolet-curable black composition is cured by ultraviolet irradiation. For example, the content of the polymerization inhibitor may be 5.0×10 relative to 100 parts by mass of the ultraviolet-curable organic material. ―4 Mass part or more 5.0×10 ―2parts by mass or less.

[0048] The ultraviolet-curable black composition may contain other additives, such as surfactants and rheology control agents such as leveling agents, and the like, and these may be used in combination.

[0049] The ultraviolet-curable black composition can be produced, for example, by mixing a black dispersion, an ultraviolet-curable organic material, and an ultraviolet curing agent. The mixing method is not particularly limited, and mixing can be performed using a mixing device such as a planetary mixer, a bead mill, or a three-roll mill.

[0050] The ultraviolet-curable black composition of the present embodiment configured as described above contains the black dispersion liquid, so that the black particles are stably dispersed and are less likely to aggregate even when stored in the atmosphere for a long period of time. Furthermore, since the composition contains an ultraviolet-curable organic material and an ultraviolet curing agent, the composition can be cured by irradiation with ultraviolet light. Furthermore, in the ultraviolet-curable black composition of the present embodiment, if the ultraviolet-curable organic material is an oligomer having an ethylenically unsaturated bond or a polyfunctional monomer having two or more ethylenically unsaturated bonds, the composition can be easily cured by irradiation with ultraviolet light. Furthermore, since the ultraviolet-curable black composition of the present embodiment contains stably dispersed black particles, a uniform black pattern can be formed by using the composition as a black resist.

[0051] [Resin composition] The resin composition of this embodiment is a cured product of the above-mentioned curable black composition. The resin composition is prepared, for example, by applying the curable black composition onto a substrate to form a coating film. If the curable black composition contains a solvent that is not UV-curable, the solvent in the coating film is volatilized and removed. Next, UV light is irradiated onto this coating film to polymerize the UV-curable organic material and produce a resin. Examples of UV light sources that can be used include halogen lamps, metal halide lamps, and UV-LEDs. Any light source with a wavelength that matches the absorption wavelength of the UV curing agent is not particularly limited.

[0052] According to the resin composition of the present embodiment configured as described above, since it is a cured product of the above-mentioned ultraviolet-curable black composition, the black particles are less likely to form aggregates and are uniformly dispersed. Therefore, the resin composition of the present embodiment has uniform light-blocking properties for visible light. The resin composition of the present embodiment can be advantageously used as a black matrix for color filters, a black resist, and a light-blocking material for CMOS camera modules.

[0053] The resin composition of the present embodiment has an OD value (Optical Density), which is an index representing the light blocking property (attenuation of transmittance) of a resin, of, for example, 2.5 or more, preferably 3.0 or more. The upper limit of the OD value is, for example, 5.0 or less. The OD value is a logarithmic representation of the degree to which light is absorbed when passing through a black film, and is defined by the following equation (2): In equation (2), I is the amount of transmitted light, and I0 is the amount of incident light. OD value = -log 10 (I / I0) (2) The better the dispersibility of the black particles in the resin composition, the higher the OD value of the resin composition tends to be.

[0054] [Black matrix for color filters] The black matrix for a color filter of this embodiment contains a cured product of the above-described ultraviolet-curable black composition. The black matrix for a color filter can be used as a black matrix for a liquid crystal display or an organic EL display. Since the black matrix for a color filter of this embodiment contains a cured product of the above-described ultraviolet-curable black composition, it has uniform visible light blocking properties. Therefore, a liquid crystal display or an organic EL display using the black matrix for a color filter of this embodiment has improved visible light contrast.

[0055] [CMOS camera module] The CMOS camera module of the present invention has a light-shielding material containing a cured product of the above-described ultraviolet-curable black composition. The CMOS camera module can be used as a solid-state imaging element of a digital camera. The CMOS camera module of this embodiment has a light-shielding material containing a cured product of the above-described ultraviolet-curable black composition, thereby improving the ability to block unwanted visible light. As a result, a digital camera using the CMOS camera module of this embodiment has high sensitivity.

[0056] Although the embodiment of the present invention has been described above, the present invention is not limited to this and can be modified as appropriate within the scope of the technical idea of ​​the invention. [Example]

[0057] In this example, the following dispersants A to F were used as the polymer dispersants. Dispersant A: A comb polymer (number average molecular weight: 3500) having a polyethyleneimine main chain and an oxyethylene and oxypropylene side chain. Dispersant B: A comb polymer (number average molecular weight: 3000) whose main chain (adsorption group) is polyethyleneimine and whose side chains have oxyethylene and oxypropylene groups. Dispersant C: A comb polymer (number average molecular weight: 4000) whose main chain (adsorption group) is polyethyleneimine and whose side chains have oxyethylene and oxypropylene groups. Dispersant D: The adsorbent group is a phosphate group and the structural formula is (C2H4O) n C 18 H 36 O9 (H3O4P) x (n=1-10, x=1-3) Phosphate ester dispersant (number average molecular weight: 1000) Dispersant E: A comb polymer (number average molecular weight: 1500) whose main chain (adsorption group) is (poly)carboxylic acid and has unsaturated alkyl groups bonded to the carboxylic acid. Dispersant F: A phosphate ester (number average molecular weight: 3000) consisting of an oxyethylene group connected to the phosphoric acid and an oxypropylene group connected to the oxyethylene group, with the adsorbent group being a phosphate group.

[0058] [Example 1] 7.4 parts by mass of zirconium dioxide powder with an average primary particle size of 50 nm, 7.3 parts by mass of metallic magnesium powder with an average primary particle size of 150 μm, and 7.3 parts by mass of magnesium oxide powder were placed in a mortar and mixed using a pestle to obtain a mixture. This mixture was fired at 700°C for 60 minutes under a nitrogen gas atmosphere using a reactor consisting of a quartz glass tube with a graphite boat inside. This fired product was dispersed in water at a concentration of 20 g / L, and 10% hydrochloric acid was gradually added so that the pH of the resulting dispersion did not fall below 1. The fired product was then washed by stirring the dispersion while maintaining the liquid temperature below 100°C. Next, 25% aqueous ammonia was added to the dispersion to adjust the pH to 7-8, and the dispersion was filtered to recover the solids. The recovered solids were redispersed in water at a concentration of 100 g / L, and once again, the mixture was acid washed and the pH adjusted with aqueous ammonia in the same manner as above, and then filtered. After repeating this acid washing and pH adjustment with aqueous ammonia twice, the filtered product was dispersed in ion-exchanged water at 500 g / L in terms of solid content, heated and stirred at 60°C, and adjusted to pH 7. The dispersion was then filtered using a suction filter, washed with an equal amount of ion-exchanged water, and dried in a hot air dryer set at 120°C to obtain a black pigment containing zirconium nitride. The resulting black pigment had an average particle size (BET diameter) of 30 nm.

[0059] 20 parts by mass of the black pigment obtained above, 4 parts by mass of the dispersant A (20% by mass relative to the black pigment), and benzyl acrylate as a solvent were weighed out in an amount such that the total amount of all components was 100 parts by mass. The weighed components were mixed for 24 hours in a bead mill using 0.5 mm diameter zirconia beads to produce a black dispersion. The resulting black dispersion had a black particle content of 20% by mass.

[0060] [Invention Examples 2 to 14 and Comparative Examples 1 to 3] The black dispersions of Invention Examples 2 to 14 and Comparative Examples 1 to 3 were produced in the same manner as Invention Example 1, except that the polymer dispersants and solvents shown in Table 1 below were used and the amounts of polymer dispersant and solvent were changed so that the content of polymer dispersant relative to the black pigment was the value shown in Table 1 below.

[0061] [evaluation] A portion of the black dispersion immediately after production was sampled and diluted with benzyl methacrylate to a particle concentration of 1% by mass to prepare a diluted black dispersion. The average particle size (converted to scattering intensity) of the black particles in the resulting diluted black dispersion was measured using a dynamic light scattering particle size distribution analyzer (Spectris Zetasizer Nano ZSP). The results are shown in Table 1 as the average particle size immediately after production.

[0062] The black dispersion was placed in a light-shielding glass bottle, sealed, and left to stand for 100 hours in an environment at 40°C. During this time, the lid of the glass bottle was opened for 5 minutes every 12 hours. After storage, the black dispersion was diluted in the same manner as before storage to prepare a diluted black dispersion, and the average particle size of the black particles was measured. The results are shown in Table 1 as the average particle size after storage at 40°C for 100 hours. [Table 1]

[0063] The results in Table 1 confirm that the black dispersions of Examples 1 to 14 of the present invention, which used Dispersants A to C, each of which had a polyalkyleneimine main chain and multiple side chains containing an oxyethylene group and an oxypropylene group as the polymer dispersant for the black dispersion, showed little change in the average particle size of the black particles even after 100 hours of storage at 40°C, and maintained a good dispersion state. In contrast, the black dispersions of Comparative Examples 1 to 3, which used Dispersants D to F, each of which had a phosphate group or a carboxylic acid group as the adsorptive functional group, became unstable after being left standing at 40°C for 100 hours, and the black particles in the dispersion settled or the average particle size increased.

[0064] [Example 15] An ultraviolet-curable black composition was produced by weighing out 20 parts by mass of the black dispersion obtained in Invention Example 1 after storage at 40°C for 100 hours, 755 parts by mass of urethane acrylate (UF-07DF, manufactured by Kyoeisha Chemical Co., Ltd.) as an ultraviolet-curable organic material, and 23 parts by mass of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide as an ultraviolet curing agent, and mixing and degassing them using a planetary mixer (Awatori Rentaro, manufactured by Thinky Corporation). The obtained ultraviolet-curable black composition had a black pigment content of 0.5% by mass and a UV curing agent content of 3.0 parts by mass per 100 parts by mass of the ultraviolet-curable organic material.

[0065] [Invention Examples 16 to 28 and Comparative Examples 4 to 6] The black dispersion obtained in the invention example shown in Table 2 below was used after storage at 40°C for 100 hours, the ultraviolet-curable organic substance and ultraviolet curing agent shown in Table 2 below were used as the black dispersion, and the ultraviolet-curable black compositions of 16 to 28 and comparative examples 4 to 6 were produced in the same manner as invention example 15, except that the blending amount w of the black dispersion, ultraviolet-curable organic substance, and ultraviolet curing agent was changed to the amounts shown in Table 2. The black pigment content of the ultraviolet-curable black compositions obtained in invention examples 15 to 28 was all 0.5 mass%.

[0066] [evaluation] The obtained ultraviolet-curable black composition was cast into a mold with a diameter of 5 mm and a depth of 1 mm, and then exposed to light at an illuminance of 4000 mW / cm using a spot-type UV-LED irradiator (8332C, manufactured by CCS Inc.). 2 The cured product was removed from the mold to obtain a black resin composition. The OD value of the obtained black resin composition was measured using a transmission densitometer (T5plus, manufactured by Ihara Electronics Co., Ltd.) The results are shown in Table 2.

[0067] [Table 2]

[0068] The results in Table 2 confirm that the black resin compositions obtained by curing the ultraviolet-curable black compositions of Inventive Examples 15 to 28, which were prepared by storing the black dispersions of Inventive Examples 1 to 14 at 40°C for 100 hours, all exhibited high OD values ​​of at least 3. In contrast, the black resin compositions obtained by curing the ultraviolet-curable black compositions of Comparative Examples 4 to 6, which were prepared by storing the black dispersions of Comparative Examples 1 to 3 at 40°C for 100 hours, all exhibited low OD values ​​of less than 2.5. [Industrial Applicability]

[0069] In the black dispersion of this embodiment, the black particles are resistant to aggregation even when stored in the atmosphere for a long period of time, and the black particles are stably dispersed in the solvent. Therefore, an ultraviolet-curable black composition containing the black dispersion of this embodiment can be used as a material for forming black patterns, such as black resists and black inks for inkjet printing. Furthermore, the resin composition of this embodiment, which is a cured product of this ultraviolet-curable black composition, can be used as a black matrix for image-forming elements used in displays such as liquid crystal displays and organic electroluminescence displays, or as a light-blocking material in image sensors such as CMOS sensors. Furthermore, the resin composition of this embodiment can also be used as a material for light-blocking materials for optical components, light-blocking filters, IR-cut filters, and coverlay films.

Claims

1. A paint containing a solvent, a black pigment, and a polymer dispersant, the solvent contains a (meth)acrylic monofunctional monomer and a bifunctional monomer each having a (meth)acryloyl group, The black pigment comprises zirconium nitride, the polymer dispersant includes a comb polymer having a main chain and a plurality of side chains bonded to the main chain, the main chain being a polyalkyleneimine, and each of the plurality of side chains being a group containing an oxyethylene group and an oxypropylene group; The black dispersion liquid, wherein the comb polymer is a polymer represented by the following general formula (I): -(-CH2-CH2-N(-R)-)n-...(I) In general formula (I), R represents a group containing an oxyethylene group and an oxypropylene group, and n represents a number of 5 to 30.

2. An ultraviolet-curable black composition comprising the black dispersion liquid described in claim 1, an ultraviolet-curable organic substance, and an ultraviolet curing agent.

3. 3. The ultraviolet-curable black composition according to claim 2, wherein the ultraviolet-curable organic material is an oligomer having an ethylenically unsaturated bond or a polyfunctional monomer having three or more ethylenically unsaturated bonds.

4. The ultraviolet-curable black composition according to claim 2 or 3, which is used for a black resist.

5. A resin composition which is a cured product of the ultraviolet-curable black composition described in claim 2 or 3.

6. A black matrix for a color filter, comprising a cured product of the ultraviolet-curable black composition described in claim 2 or 3.

7. A CMOS camera module having a light-blocking material containing a cured product of the ultraviolet-curable black composition described in claim 2 or 3.

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