Dispersions, curable compositions, cured products thereof, and electronic devices

Abstract

Provided are: a dispersion containing a polymerizable compound (a1), a colorant (b), and a dispersant (c), wherein the colorant (b) contains at least a bis-benzofuranone pigment, the content of the colorant (b) is in the range of 1-50 mass% with respect to the entire dispersion, and the dispersion is solvent-free; and a curable composition that can be formed by an inkjet method. The curable composition has excellent curability and storage stability, and the cured product has excellent heat resistance, light resistance, moisture resistance, light transmittance in the visible region (hiding performance), and adhesion to a substrate.

Description

[Technical Field]

[0001] The present invention relates to a dispersion, a curable composition, a cured product of the curable composition, an LED element containing the cured product, and an electronic device using the cured product. [Background technology]

[0002] Display devices such as liquid crystal displays, plasma displays, organic EL displays, and mini-LED displays are widely used. In recent years, there has been active development toward the practical application of micro-LED displays, which offer superior characteristics such as brightness, color gamut, contrast, and reliability, and can achieve low power consumption by using high-efficiency LEDs as a light source. From the viewpoint of maintaining the characteristics of light-emitting elements and improving image quality and contrast, various developments have been continuously made regarding materials that constitute a light-blocking layer (black matrix) that does not transmit light. In the past, a black matrix forming material for color liquid crystal display devices was disclosed, which includes a black pigment that is a mixture of at least two types of materials, including a photopolymerizable compound, a photopolymerization initiator, an alkali-soluble resin, carbon black coated with resin, and a metal oxide (see Patent Document 1). In recent years, Patent Document 2 has disclosed a photosensitive resin composition comprising an alkali-soluble resin with a specific softening point, a photopolymerizable compound, a photopolymerization initiator, a novolac resin with a softening point of 130°C or higher, and a light-shielding agent containing carbon black coated with a dye. This composition is said to be capable of forming a black matrix with high resistance and optical density that is less susceptible to shape changes due to heating. Patent Document 3 discloses a photosensitive resin composition comprising an alkali-soluble resin containing a novolac resin, a photopolymerizable compound containing a specific dendritic polymer, a photopolymerization initiator, and carbon black. This composition is less prone to excessive flow upon heating and can form a finely patterned colored cured film of a desired size. It is suitable for forming a black matrix or black column spacer in a liquid crystal display panel, or for forming a partitioning bank for the light-emitting layer in an organic EL element. Patent Document 4 discloses a photosensitive colored composition for forming colored spacers, which contains a colorant containing a specific amount of organic pigment and carbon black, an alkali-soluble resin, a photopolymerization initiator, an ethylenically unsaturated compound, a solvent, and a dispersant, and specifies the highest transmittance at a specific wavelength. This composition is said to have high light-shielding properties, control the step difference between the main spacer and the sub-spacer, and suppress light leakage in the visible region. Patent Document 5 discloses a photosensitive resin composition for black resists comprising an alkali-soluble resin of a specific structure, a photopolymerizable compound having at least two ethylenically unsaturated bonds, an oxime ester-based photopolymerization initiator, carbon black, a predetermined amount of a specific coupling agent and a specific surfactant, and a solvent. This composition is said to be capable of forming a black matrix with low reflectivity and high resolution, and when partitions are formed with a film thickness of 2 μm or more, it can impart the pattern cross-sectional shape and surface ink-repellent properties required for partitions. Patent Document 6 discloses a photosensitive resin composition for black resist comprising an alkali-soluble resin containing an unsaturated group, a photopolymerizable compound having at least two or more unsaturated bonds, a photopolymerization initiator, carbon black whose surface is coated with a dye, and aluminum oxide fine particles with a specific refractive index. This composition possesses both high light shielding properties and low reflectivity, and enables the formation of highly detailed patterns without jagged edges. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2000-147240 [Patent Document 2] Japanese Patent Publication No. 2017-198918 [Patent Document 3] Japanese Patent Publication No. 2018-013716 [Patent Document 4] Japanese Patent Publication No. 2021-192120 [Patent Document 5] Japanese Patent Publication No. 2022-173086 [Patent Document 6] Japanese Patent Publication No. 2023-051765

Summary of the Invention

Problems to be Solved by the Invention

[0004] Existing black matrix forming materials such as Patent Documents 1 to 6 use carbon black as a black material, and the ultraviolet curability of the material is not good. Therefore, it is necessary to use a pre-cure (drying) process, a curing process by ultraviolet rays, and a heat curing process (heating in post-baking) in combination. Furthermore, since an etching process by photolithography may also be involved, the manufacturing process is complicated and the energy consumption tends to increase, and there is still room for improvement. On the other hand, regarding the composition itself as a black matrix forming material applied to electronic devices using light-emitting elements such as LEDs, in addition to the manufacturing cost of the compound to be blended, consideration for the environment, response to the thinning of the display, and further from the viewpoints of simplification of the manufacturing process and improvement of safety, a solventless composition that can be applied by an inkjet method and does not require an annealing process is required.

[0005] As a result of intensive studies, the present inventors have found that a dispersion liquid selected with a specific colorant and a polymerizable compound as constituent components is excellent in dispersibility and storage stability, a curable composition prepared from such a dispersion liquid is excellent in curability, and a molded product can be formed by an inkjet method. In addition, the obtained cured product is excellent in various physical properties such as heat resistance, light resistance, moisture resistance, and low light transmittance (concealment performance) in the visible region, and is useful as a black member material for electronic devices having a light-emitting element such as an LED element. An object of the present invention is to provide a curable composition capable of forming a cured product excellent in curability and storage stability, and also excellent in heat resistance, light resistance, moisture resistance, low light transmittance (concealment performance) in the visible region, and adhesion to a substrate by an inkjet method.

Means for Solving the Problems

[0006] The present invention has the following aspects. [1] A dispersion comprising a polymerizable compound (a1), a colorant (b), and a dispersant (c), wherein the colorant (b) contains at least a bisbenzofuranone pigment, the content of the colorant (b) relative to the whole dispersion is in the range of 1 to 50% by mass, and the dispersion does not contain a solvent. [2] A dispersion of [1] wherein the viscosity of the polymerizable compound (a1) at 25°C is 30 mPa·s or less. [3] A dispersion of [1] or [2] in which the polymerizable compound (a1) contains a monofunctional (meth)acrylate. [4] A dispersion of [3] wherein the monofunctional (meth)acrylate is a monofunctional (meth)acrylate having an aromatic ring. [5] A dispersion of any of [1] to [4], wherein the average particle size (D50) of the bisbenzofuranone pigment in the colorant (b) is 50 to 500 nm. A curable composition comprising a dispersion of any of [1] to [5] and a polymerizable compound (a2). [7] The curable composition of [6], wherein the polymerizable compound (a2) contains a (meth)acrylate having a hydroxyl group. [8] The curable composition of [6] or [7], wherein the polymerizable compound (a2) contains a compound having two or more (meth)acrylate groups. [9] Furthermore, a curable composition comprising a photopolymerization initiator (d) as one of [6] to [8].

[10] The curable composition of [9] wherein the photopolymerization initiator (d) comprises an oxime-based photopolymerization initiator.

[11] A curable composition according to any of [6] to

[10] , wherein the content of the coloring agent (b) is 1 to 50% by mass relative to the total mass of the curable composition.

[12] A curable composition according to any of [6] to

[11] , wherein the average particle size (D50) of the bisbenzofuranone pigment in the colorant (b) is 50 to 500 nm.

[13] A curable composition that is curable by active energy rays, any of the curable compositions of [6] to

[12] .

[14] A curable composition according to any of [6] to

[13] , having a viscosity of 3 to 30 mPa·s at 25°C.

[15] A curable composition according to any of [6] to

[14] that does not contain a solvent.

[16] A cured product of any of the curable compositions [6] to

[15] . A method for producing a cured product, comprising the step of curing any of the curable compositions of

[17] [6] to

[15] by irradiating it with active energy rays.

[18] A method for manufacturing the curable composition according to

[17] , wherein the curable composition is molded by an inkjet method.

[19] An electronic device using a cured product of any of the curable compositions [6] to

[15] . [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a curable composition that can form a cured product by an inkjet method that is excellent in curability and storage stability, as well as excellent in heat resistance, light resistance, moisture resistance, low light transmittance in the visible region (opacity), and adhesion to a substrate. [Brief explanation of the drawing]

[0008] [Figure 1] This figure schematically shows an example of the configuration of a microLED display, which is one embodiment of an electronic device in which the cured product of the curable composition of the present invention is used as the black layer on top of the wall material. [Figure 2] This figure schematically shows an example of the configuration of a microLED display, which is one embodiment of an electronic device using a cured product of the curable composition of the present invention as a black matrix. [Modes for carrying out the invention]

[0009] The present invention relates to a dispersion containing a polymerizable compound (a1), a colorant (b), and a dispersant (c), wherein the colorant (b) contains at least a bisbenzofuranone pigment, the content of the colorant (b) in relation to the entire dispersion is in the range of 1 to 50% by mass, and the dispersion does not contain a solvent (hereinafter simply referred to as "the dispersion of the present invention"). The present invention also relates to a curable composition (hereinafter simply referred to as "the curable composition of the present invention") containing the above-described dispersion and a polymerizable compound (a2). In this specification, a composition containing the dispersion of the present invention, a polymerizable compound (a2), and various components described later is referred to as a curable composition. In this specification, "(meth)acrylate" is a general term encompassing acrylate, methacrylate, and both. "(meth)acrylic" is a general term encompassing acrylic, methacrylic, and both. "(meth)acryloyloxy group" is a general term encompassing acryloyloxy group, methacryloyloxy group, and both.

[0010] The dispersion of the present invention exhibits excellent dispersibility of coloring agent (b) and also has excellent storage stability. The curable composition of the present invention contains the dispersion of the present invention as a constituent component and exhibits excellent curability and storage stability. Furthermore, a cured product with excellent heat resistance, light resistance, moisture resistance, low light transmittance in the visible region (opacity), and adhesion to a substrate can be formed from the curable composition of the present invention by an inkjet method. First, the composition of the dispersion liquid of the present invention will be described.

[0011] The viscosity of the polymerizable compound (a1) constituting the dispersion of the present invention at 25°C is preferably 30 mPa·s or less, more preferably in the range of 1 to 20 mPa·s, even more preferably in the range of 2 to 10 mPa·s, and even more preferably in the range of 2 to 6 mPa·s. When the viscosity of the polymerizable compound (a1) at 25°C is within the above range, the dispersion of the present invention tends to have excellent dispersibility, low viscosity, and is easy to handle.

[0012] The polymerizable compound (a1) preferably contains a monofunctional (meth)acrylate. The presence of a monofunctional (meth)acrylate makes it easier to reduce the viscosity of the dispersion of the present invention, and of the curable composition of the present invention, which will be described later and contains the dispersion of the present invention as a component. In the dispersion of the present invention, monofunctional (meth)acrylates having an aromatic ring are preferred, such as 2-phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, m-phenoxybenzyl (meth)acrylate, 1-naphthalenemethyl (meth)acrylate, methylphenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, and phenoxy(polyethylene glycol) (meth)acrylate. One type of monofunctional (meth)acrylate having an aromatic ring may be used alone, or two or more types may be used in combination. The inclusion of a monofunctional (meth)acrylate containing an aromatic ring tends to improve the dispersibility of the bisbenzofuranone pigment contained in the colorant (b). Since bisbenzofuranone pigments have an aromatic ring structure, it is presumed that using a monofunctional (meth)acrylate containing an aromatic ring as the polymerizable compound (a1) increases the affinity between the two, improves solubility, and makes it easier to reduce the viscosity of the resulting dispersion. The polymerizable compound (a1) is preferably composed of a monofunctional (meth)acrylate having the aromatic ring described above, to the extent that it can maintain the viscosity of the dispersion of the present invention and the dispersibility of the colorant (b). It may also contain a monofunctional (meth)acrylate having an aromatic ring and two or more compounds having (meth)acrylate groups that can constitute the curable composition of the present invention, as described later. Furthermore, the polymerizable compound (a1) may contain, in addition to the monofunctional (meth)acrylate having the aromatic ring described above, other monofunctional (meth)acrylates that do not have an aromatic ring. In particular, it is preferable to include them together with monofunctional (meth)acrylates having an alicyclic group. In the dispersion of the present invention, it is preferable that the total polymerizable compound contains 5% by mass or more of monofunctional (meth)acrylate having an aromatic ring, and more preferably 10% by mass or more, in order to achieve low viscosity and good solubility. The content of polymerizable compound (a1) in the dispersion of the present invention is preferably in the range of 40 to 99% by mass, more preferably in the range of 50 to 90% by mass, and even more preferably in the range of 60 to 85% by mass.

[0013] The colorant (b) constituting the dispersion of the present invention contains at least a bisbenzofuranone pigment. Bisbenzofuranone pigments have higher light transmittance in the 310 nm to 370 nm range compared to carbon black. Therefore, it is presumed that using a colorant (b) containing at least a bisbenzofuranone pigment will significantly improve curability by active energy rays such as ultraviolet light compared to black material forming materials containing carbon black. Therefore, the curable composition of the present invention, described later, containing the dispersion of the present invention, is considered to have good curability and can improve the light resistance and low light transmittance (opacity) of the resulting cured product in the visible region. The content of colorant (b) in the total dispersion of the present invention is in the range of 1 to 50% by mass, preferably in the range of 5 to 45% by mass, more preferably in the range of 10 to 40% by mass, and even more preferably in the range of 15 to 35% by mass. When the content of colorant (b) is within the above range, the dispersibility of colorant (b) in the dispersion of the present invention can be well maintained. Furthermore, the curability of the curable composition of the present invention, described later, the light resistance of the cured product of the curable composition of the present invention, and the low light transmittance (opacity) in the visible region can be improved. Bisbenzofuranone pigments may have structures represented by the following general formulas (I) to (IV), or their isomers or tautomers. For example, general formulas (I) to (III) are cis-trans isomers, and there may be two or more of these structures.

[0014] [ka]

[0015] In the formula, R 1 and R 2 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. 3 and R4 is independently, R 10 , OR 11 , SR 11 , COR 11 , CONR 11 R 12 , NR 11 , COR 12 , OCOR 11 , COOR 11 , SCOR 11 , OCSR 11 , COSR 11 , CSOR 11 , CN, a halogen atom or a hydroxyl group. Here, R 10 represents an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, an aralkyl group having 7 to 30 carbon atoms or a heterocyclic group having 2 to 20 carbon atoms, R 11 and R 12 each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, an aralkyl group having 7 to 30 carbon atoms or a heterocyclic group having 2 to 20 carbon atoms. a and b each independently represent an integer of 0 to 4. The bisbenzofuranone-based pigment itself having a structure represented by any of the above general formulas (I) to (IV) is known, and can be obtained, for example, by the method described in JP-T-2012-515233, the method of Example 12b of WO 2000 / 024736, etc. Commercially available products can also be used as the bisbenzofuranone-based pigment, and examples thereof include "Irgaphor (registered trademark) Black S 0100CF" (trade name) manufactured by BASF.

[0016] In the colorant (b), the average particle diameter (D50) of the bisbenzofuranone-based pigment is preferably 50 to 500 nm, more preferably 100 to 400 nm, and still more preferably 150 to 350 nm. When the average particle diameter (D50) of the bisbenzofuranone-based pigment is 50 nm or more, the curable composition of the present invention containing the dispersion liquid of the present invention becomes easy to handle, and clogging of nozzles when the inkjet method is applied hardly occurs. Further, the light transmittance of the cured product of the curable composition of the present invention can be made sufficiently low, and the hiding performance can be maintained. The average particle diameter (D50) is the volume-based cumulative 50% diameter, and is determined by laser diffraction and scattering.

[0017] The dispersion of the present invention may further contain other colorants as colorant (b) along with a bisbenzofuranone pigment, to the extent that they do not impair the effects of the present invention. Examples of such other colorants include general organic pigments, inorganic pigments, dyes, etc. Examples of organic pigments include diketopyrrolopyrrole pigments, azo pigments, phthalocyanine pigments such as copper phthalocyanine, anthraquinone pigments, quinacridone pigments, dioxazine pigments, perinone pigments, perylene pigments, thioindigo pigments, isoindoline pigments, isoindolinone pigments, quinophthalone pigments, surene pigments, and metal complex pigments. Examples of inorganic pigments include titanium dioxide, zinc oxide, zinc sulfide, lead white, calcium carbonate, precipitated barium sulfate, white carbon, alumina white, kaolin gray, talc, bentonite, black iron oxide, cadmium red, red iron oxide, molybdenum red, molybdate orange, chromium vermilion, yellow lead, cadmium yellow, yellow iron oxide, titanium yellow, chromium oxide, viridian, titanium cobalt green, cobalt green, cobalt chromium green, Victoria green, ultramarine, dark blue, cobalt blue, cerulean blue, cobalt silica blue, cobalt zinc silica blue, manganese violet, cobalt violet, and silica (silicon oxide). Examples of dyes include azo dyes, anthraquinone dyes, condensed polycyclic aromatic carbonyl dyes, indigoid dyes, carbonium dyes, phthalocyanine dyes, methine dyes, and polymethine dyes.

[0018] Furthermore, examples of black colorants include black organic pigments such as carbon black, perylene black, aniline black, and benzofuranone pigments; mixed organic pigments obtained by mixing two or more pigments having colors such as red, blue, green, purple, yellow, magenta, and cyan to create a pseudo-black color; fine particles of metals such as graphite, titanium, copper, iron, manganese, cobalt, chromium, nickel, zinc, calcium, and silver; and black inorganic pigments such as oxides, composite oxides, sulfides, nitrides, and oxynitrides of the above metals. Examples of white colorants include titanium dioxide, barium carbonate, zirconium oxide, calcium carbonate, barium sulfate, alumina white, and silicon dioxide. Other colorants may be used individually with bisbenzofuranone pigments, or two or more may be used in combination with bisbenzofuranone pigments. Among these, phthalocyanine pigments are preferred, and copper phthalocyanine pigments are more preferred, from the viewpoint of further improving the low light transmittance (opacity), heat resistance, and moisture resistance in the cured product of the curable composition of the present invention, which will be described later. An example of a copper phthalocyanine pigment is "FASTOGEN BLUE AE8" (product name; equivalent to pigment PB15:6) manufactured by Toyo Ink Co., Ltd. If a coloring agent other than bisbenzofuranone pigments is included as coloring agent (b), the amount is preferably in the range of 1 to 75% by mass, and more preferably in the range of 5 to 30% by mass, relative to the content of bisbenzofuranone pigments.

[0019] The dispersant (c) is used in the dispersion of the present invention to further enhance the dispersion stability of the colorant (b) in the polymerizable compound (a1). As the dispersant (c), a polymeric dispersant is preferred, which has both a pigment affinity group that chemically bonds to or adsorbs to the pigment surface and a polymer chain or group that is solvent-friendly. The polymeric dispersant improves the wettability of the pigment to the dispersion medium, promotes the deaggregation of the pigment, stabilizes the particle size and viscosity of the pigment through its steric hindrance and electrostatic repulsion effect, and further improves the viscosity reduction and storage stability of the dispersion liquid of the present invention or the curable composition of the present invention described later. Examples of polymer dispersants include polyester-based, acrylic-based, polyurethane-based, polyallylamine-based, carbodiimide-based, and polyamide-based materials. Commercially available products can be used as the dispersant (c), for example, Ajisper (Ajisper is a registered trademark) PB821, PB822, PB824 from Ajinomoto Fine Techno Co., Ltd.; Solsperse (Solsperse is a registered trademark) 24000GR, 32000, 33000, 39000, S86000 from Lubrizol; Disparon DA-703-50 from Kusumoto Chemical Co., Ltd.; EFKA (EFKA is a registered trademark) PX4701, PX4703 from BASF; BYK2013, BYK9151 from BYK, etc. The amount of dispersant (c) used is preferably in the range of 10 to 100% by mass relative to the colorant (b), and in the curable composition of the present invention described later, a range of 15 to 60% by mass is more preferable from the viewpoint of superior inkjet ejection stability and dispersibility of the colorant (b). Furthermore, to enhance the effect of polymer dispersants that stabilize phthalocyanine blue and green, organic violet pigments, etc., synergists may be further included. A synergist is a pigment derivative in which polar groups such as alkylamino groups, carboxyl groups, sulfonic acid groups, and phthalimide groups are introduced into the pigment skeleton. It adsorbs to the pigment surface through π-π interactions and hydrophobic interactions, modifying the pigment surface to be acidic or basic, and increasing the electrostatic repulsion between pigment particles, thereby improving dispersion stability. In addition, the electrostatic adsorption force with the solvent-philic portion of the dispersant is also increased, allowing the dispersant to be strongly adsorbed to the pigment surface via the synergist, further improving dispersion stability. Commercially available synergists can be used, such as BYK-SYNERGIST 2100 from BYK and Solsperse (Solsperse is a registered trademark) 5000 and 5000S Synergist from Lubrizol.

[0020] The dispersion of the present invention may further contain surfactants from the viewpoint of improving handling and dispersibility of the colorant (b), as well as the discharge stability and wettability to the substrate of the curable composition of the present invention, which will be described later. Examples of surfactants include anionic surfactants such as dialkyl sulfosuccinates, alkylnaphthalene sulfonates, and fatty acid salts; nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, and polyoxyethylene-polyoxypropylene block copolymers; cationic surfactants such as alkylamine salts and quaternary ammonium salts; silicone-based surfactants having silicone chains, silicone chains and polymer chains such as poly(meth)acrylate chains, and silicone-based surfactants having polyether chains as side chains or terminals and a polysiloxane structure in the main chain; and preferably hydrophobic organic fluoro compounds such as fluorine-based surfactants having perfluoroalkyl chains, oily fluorine-based compounds (e.g., fluorine oils), and solid fluorine compound resins (e.g., tetrafluoroethylene resins). These can be obtained as commercially available products such as the "MegaFac®" series from DIC Corporation, the "Futergent®" series from Neos Corporation, the "BYK®" series from BYK Corporation, the "TEGO® Rad" series from Evonik Corporation, the "DISPARLON® OX" series from Kusumoto Chemical Co., Ltd., and "Polyflow No. 7," "Florence AC-300," and "Florence AC-303" from Kyoeisha Chemical Co., Ltd. If the dispersion of the present invention contains a surfactant, the amount is preferably 0.05 to 1% by mass, and more preferably 0.1 to 0.8% by mass, relative to the total amount of the dispersion of the present invention.

[0021] The dispersion of the present invention is characterized by being solvent-free. In this specification, "solvent" means a compound that dissolves the polymerizable compound (a1), the dispersant (c), and the polymerizable compound (a2) and photopolymerization initiator (d) described later, and does not react with these components. Such solvents include ethers such as 3-methoxy-1-butanol, 3-methoxy-3-methylbutanol, tetrahydrofuran, tetrahydropyran, 1,4-dioxane, anisole, and phenethole; Esters such as methyl lactate, ethyl lactate, butyl lactate, methyl 2-hydroxyisobutanoate, ethyl acetate, butyl acetate, pentyl formate, isopentyl acetate, butyl propionate, isopropyl butyrate, ethyl butyrate, butyl butyrate, methyl pyruvate, methyl acetoacetate, and γ-butyrolactone; Ether esters such as ethyl methoxyacetate, butyl methoxyacetate, methyl ethoxyacetate, ethyl ethoxyacetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, methyl 2-methoxypropionate, ethyl 2-ethoxypropionate, ethyl 2-ethoxypropionate, ethyl 2-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate; Glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol dipropyl ether, and diethylene glycol dibutyl ether; Glycol ether esters such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, and dipropylene glycol methyl ether acetate; Alcohols such as methanol, ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol, and propylene glycol; Ketones such as acetone, 2-butanone, 2-heptanone, 4-methyl-2-pentanone, cyclopentanone, and cyclohexanone; Amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone; Aliphatic hydrocarbons such as hexane and octane; Examples include aromatic hydrocarbons such as benzene, toluene, and xylene. Furthermore, in this specification, "solvent-free" means that the solvent content in the dispersion of the present invention is 1% by mass or less. The solvent content is preferably 0.5% by mass or less, and more preferably 0.1% by mass or less. The dispersion of the present invention can effectively disperse a colorant (b) containing at least a bisbenzofuranone pigment without containing a solvent, and exhibits excellent storage stability. Therefore, the manufacturing process of the dispersion of the present invention can be simplified, and safety during handling can be improved. Furthermore, the curable composition of the present invention, described later, can be coated by an inkjet method, and annealing treatment is unnecessary during curing.

[0022] The dispersion of the present invention can be produced by supplying the polymerizable compound (a1), colorant (b), and dispersant (c) using a conventional disperser such as a bead mill or stirrer, stirring and mixing to disperse the colorant (b). When using a bead mill, glass beads or zirconia beads can be used as beads. In addition to bead mills, various known and conventional dispersion machines can be used as dispersion machines, such as ultrasonic homogenizers, high-pressure homogenizers, paint shakers, ball mills, roll mills, sand mills, sand grinders, Dino mills, Dispermats, SC mills, and nanomizers.

[0023] Next, the composition of the curable composition of the present invention will be described. The curable composition of the present invention contains the dispersion of the present invention described above and a polymerizable compound (a2). The curable composition of the present invention preferably contains a (meth)acrylate having a hydroxyl group as the polymerizable compound (a2). Examples of (meth)acrylates having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-ethylhexyl diglycol (meth)acrylate, diethylene glycol mono(meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 1,4-cyclohexanedimethanol monoacrylate, and 1-(acryloyloxy)-3-(methacryloyloxy)-2-propanol. These (meth)acrylates having a hydroxyl group may be used individually or in combination of two or more. Among these, 2-hydroxypropyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are preferred, and 4-hydroxybutyl acrylate is more preferred, from the viewpoint of being widely available, relatively inexpensive, and having good curability, inkjet ejectability, and excellent physical properties such as moisture resistance and heat resistance of the cured product. When the polymerizable compound (a2) contains a (meth)acrylate having a hydroxyl group, the moisture resistance, heat resistance, and adhesion to the substrate of the cured product formed from the curable composition of the present invention are improved.

[0024] The content of the polymerizable compound (a2), a (meth)acrylate having a hydroxyl group, is preferably in the range of 5 to 50% by mass, more preferably in the range of 8 to 40% by mass, and even more preferably in the range of 10 to 35% by mass, relative to the total mass of the curable composition of the present invention. When the curable composition of the present invention contains a (meth)acrylate having a hydroxyl group within this range, the curability is improved, and the performance of the cured product after curing, such as moisture resistance, heat resistance, and adhesion to the substrate, is enhanced.

[0025] The curable composition of the present invention preferably contains a compound having two or more (meth)acrylate groups as the polymerizable compound (a2). Examples of compounds having two or more (meth)acrylate groups include ethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 2-methyl-1,8-octanediol di(meth)acrylate, and 2-butyl-2-ethyl-1,3-propanediol di(meth)acrylate. Glycol di(meth)acrylates such as acrylate, tricyclodecanedimethanol di(meth)acrylate, ethoxylated (2) neopentyl glycol di(meth)acrylate [compound obtained by di(meth)acrylate of a 2-mol adduct of neopentyl glycol ethylene oxide], propoxylated (2) neopentyl glycol di(meth)acrylate [compound obtained by di(meth)acrylate of a 2-mol adduct of neopentyl glycol propylene oxide], and hydroxypivalic acid neopentyl glycol di(meth)acrylate;

[0026] Diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, tetrapropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, bis(4-acryloxypolyethoxyphenyl)propane, and other alkylene glycol di(meth)acrylates; Di(meth)acrylate of tris(2-hydroxyethyl) isocyanurate; Dimethylol tricyclodecane di(meth)acrylate, caprolactone-modified hydroxypivalate neopentyl glycol di(meth)acrylate; Bisphenol A di(meth)acrylate, propylene oxide-modified bisphenol A type di(meth)acrylate, ethylene oxide-modified bisphenol A type di(meth)acrylate, bisphenol F di(meth)acrylate, propylene oxide-modified bisphenol F type di(meth)acrylate, ethylene oxide-modified bisphenol F type di(meth)acrylate; Trifunctional (meth)acrylates such as pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane ethylene oxide modified tri(meth)acrylate, trimethylolpropane propylene oxide modified tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, modified glycerin tri(meth)acrylate, glycerin propylene oxide adduct tri(meth)acrylate, and glycerin ethylene oxide adduct tri(meth)acrylate; Tetrafunctional (meth)acrylates such as pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, and tetramethylolmethane tetra(meth)acrylate; Examples include hexafunctional (meth)acrylates such as dipentaerythritol hexa(meth)acrylate and caprolactone-modified dipentaerythritol hexa(meth)acrylate; and so on.

[0027] Furthermore, urethane (meth)acrylate and amino (meth)acrylate can be used as compounds having two or more (meth)acrylate groups. Urethane (meth)acrylate and amino (meth)acrylate may be monomers, oligomers, or polymers. In this specification, "monomer" refers to a compound with a molecular weight (or weight-average molecular weight, if a molecular weight distribution exists) of 1000 or less. The molecular weight (or weight-average molecular weight, if a molecular weight distribution exists) of monomers is between 50 and 1000. "Oligomer" generally refers to a polymer having a finite number of constituent units (generally 5 to 100) based on monomers, with a weight-average molecular weight exceeding 1000 but less than 30000. "Polymer" refers to a polymer with a weight-average molecular weight of 30000 or more. The weight-average molecular weight is measured by gel permeation chromatography (GPC) and is calculated as a value equivalent to standard polystyrene.

[0028] Examples of urethane (meth)acrylates include aliphatic urethane (meth)acrylates and aromatic urethane (meth)acrylates. The weight-average molecular weight of the urethane (meth)acrylate is preferably 1,000 to 30,000, and more preferably 2,000 to 20,000. Commercially available urethane (meth)acrylates can also be used, for example, U-2PPA, U-4HA, U-6HA, U-6LPA, U-15HA, U-324A, UA-122P, UA5201, UA-512 etc. from Shin Nakamura Chemical Industry Co., Ltd.; and CN965NS, CN964A85, CN964, CN959, CN962, CN963J85, CN965, CN982B88 from ARKEMA (Sartomer). Examples include CN981, CN983, CN991, CN996, CN9002, CN9906NS, CN9007, CN9009, CN9010, CN9011, CN9178, CN9788, CN9893; and EBECRYL230, EBECRYL270, EBECRYL8402, EBECRYL8804, EBECRYL8807, EBECRYL9270, KRM8191, etc., manufactured by Daicel Ornex.

[0029] Amino(meth)acrylate is an amine-modified (meth)acrylate having an amino group. The number-average molecular weight of amino(meth)acrylate is preferably 500 to 20000, more preferably 600 to 10000, and even more preferably 800 to 5000. Commercially available amino(meth)acrylates can also be used, such as EBECRYL7100 and EBECRYL80 from Daicel Ornex, and CN551 from ARKEMA (Sartomer).

[0030] Compounds having two or more (meth)acrylate groups may be used individually or in combination of two or more. The content of compounds having two or more (meth)acrylate groups in the curable composition of the present invention is preferably in the range of 0.5 to 20% by mass, more preferably in the range of 1 to 15% by mass, and even more preferably in the range of 2 to 12% by mass, based on the total mass of the curable composition of the present invention. When the curable composition of the present invention contains two or more compounds having (meth)acrylate groups within this range, the curability of the curable composition of the present invention is improved, and the properties of the cured product formed from the curable composition of the present invention, such as flexibility and adhesion to the substrate, are also improved. Furthermore, when using a single compound as a compound having two or more (meth)acrylate groups, using a compound having three or more (meth)acrylate groups, such as trimethylolpropaneethylene oxide-modified triacrylate, or the trifunctional (meth)acrylates and tetrafunctional (meth)acrylates exemplified above, can increase the hardness of the cured product formed from the curable composition of the present invention, and also effectively improve heat resistance and moisture resistance.

[0031] The curable composition of the present invention may further contain, as polymerizable compound (a2), (meth)acrylate having a hydroxyl group and a compound having two or more (meth)acrylate groups as described above, (meth)acrylate having a phosphate group and (meth)acrylate having a cyclic skeleton.

[0032] Examples of (meth)acrylates having a phosphate group include alkylene (meth)acrylates such as methylene (meth)acrylate phosphate, ethylene (meth)acrylate phosphate, propylene (meth)acrylate phosphate, and tetramethylene (meth)acrylate phosphate, as well as phosphate esters of polyethylene glycol monoacrylate and phosphate esters of polypropylene glycol monomethacrylate.

[0033] (Meth)acrylates containing a phosphate group can also be commercially available, such as "EBECRYL168" from Daicel Ornex, "KAYAMER PM-2" and "KAYAMER PM-21" from Nippon Kayaku Co., Ltd., "Hosmer M", "Hosmer PE", and "Hosmer PP" from Unichemical Co., Ltd., "Light Ester P-1M", "Light Acrylate P-1A(N)", and "Light Ester P-2M" from Kyoeisha Chemical Co., Ltd., and "JPA-514" from Johoku Chemical Industry Co., Ltd.

[0034] (Meth)acrylates having a phosphate group may be used individually or in combination of two or more types. When the curable composition of the present invention contains a (meth)acrylate having a phosphate group as a polymerizable compound (a2), the amount is preferably in the range of 0.1 to 10% by mass, and more preferably in the range of 0.2 to 8% by mass, relative to the total mass of the curable composition of the present invention. When the curable composition of the present invention contains a (meth)acrylate having a phosphate group within this range, the curability of the curable composition of the present invention is improved, and the performance of the cured product formed from the curable composition of the present invention, such as adhesion to the substrate, is also improved.

[0035] Examples of (meth)acrylates having a cyclic skeleton include monofunctional (meth)acrylates having an aromatic ring, (meth)acrylates having a cyclic skeleton containing a heteroatom, and (meth)acrylates having an alicyclic skeleton. Examples of monofunctional (meth)acrylates having an aromatic ring include the monomers mentioned above in polymerizable compound (a1). Examples of (meth)acrylates having a cyclic skeleton containing heteroatoms include (meth)acryloylmorpholine, N-(meth)acryloyloxyethylhexahydrophthalimide, tetrahydrofurfuryl(meth)acrylate, and cyclic trimethylolpropaneformal(meth)acrylate. (Meth)acrylates having a cyclic skeleton containing heteroatoms can also be commercially available, such as "Viscote 150" and "Viscote 200" manufactured by Osaka Organic Chemical Industry Co., Ltd. Examples of (meth)acrylates having an alicyclic skeleton include monofunctional (meth)acrylates having cyclic aliphatic groups, such as cyclohexyl (meth)acrylate, 4-t-butylcyclohexyl (meth)acrylate, tricyclodecanedimethanol mono(meth)acrylate, adamantyl (meth)acrylate, cyclohexanedimethanol mono(meth)acrylate, trimethylcyclohexyl (meth)acrylate, isobornyl (meth)acrylate, t-butylcyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and dicyclopentenyloxyethyl (meth)acrylate.

[0036] The (meth)acrylate having a cyclic skeleton may be used alone or in combination of two or more types. Including a (meth)acrylate having a cyclic skeleton makes it easy to adjust the viscosity of the curable composition of the present invention to a suitable viscosity range for molding by inkjet printing. Furthermore, the shrinkage of the cured product formed from the curable composition of the present invention is reduced, resulting in excellent adhesion and other properties. In this specification, (meth)acrylates having a hydroxyl group and a cyclic skeleton are classified as (meth)acrylates having a hydroxyl group, and (meth)acrylates having a phosphate group and a cyclic skeleton are classified as (meth)acrylates having a phosphate group. Furthermore, monomers having two or more (meth)acrylate groups shall be classified as (meth)acrylates having hydroxyl groups or (meth)acrylates having phosphate groups if they have one or more hydroxyl groups or phosphate groups, regardless of the presence or absence of a cyclic skeleton, and shall be classified as compounds having two or more (meth)acrylate groups if they do not have either hydroxyl groups or phosphate groups. In other words, (meth)acrylates having a cyclic skeleton include mono(meth)acrylates that have a cyclic skeleton but do not have either a hydroxyl group or a phosphate group.

[0037] When the curable composition of the present invention contains a (meth)acrylate having a cyclic skeleton as the polymerizable compound (a2), the amount is preferably within 65% by mass, more preferably within 60% by mass, and even more preferably within 55% by mass, relative to the total mass of the curable composition of the present invention. When the curable composition of the present invention contains a (meth)acrylate having a cyclic skeleton in an amount of 60% by mass or less, the curability of the curable composition of the present invention is improved, its storage stability and the shrinkage of the formed cured product are suppressed, and performance such as adhesion to the substrate is improved. Here, when a (meth)acrylate having a cyclic skeleton is blended as the polymerizable compound (a2), such a (meth)acrylate having a cyclic skeleton may contain monomers of the same type as the monofunctional (meth)acrylate having an aromatic ring described above as polymerizable compound (a1). In this case, the content of the cyclic skeleton (meth)acrylate in the entire curable composition of the present invention can be calculated from the total amount of the monofunctional (meth)acrylate having an aromatic ring in the polymerizable compound (a1) derived from the dispersion of the present invention and the cyclic skeleton (meth)acrylate incorporated as polymerizable compound (a2).

[0038] Furthermore, the (meth)acrylate having a hydroxyl group, the compound having two or more (meth)acrylate groups, the (meth)acrylate having a phosphate group, and the (meth)acrylate having a cyclic skeleton described above may be compounds derived from biomass raw materials. In such cases, the curable composition of the present invention itself can be considered an environmentally conscious product, which is more preferable from the viewpoint of reducing environmental impact.

[0039] The curable composition of the present invention may further contain other polymerizable compounds different from the polymerizable compound (a2) described above. Other polymerizable compounds include monofunctional polymerizable compounds, and polymerizable compounds having two or more polymerizable groups (hereinafter referred to as "polyfunctional polymerizable compounds"), which differ from the compounds having two or more (meth)acrylate groups described above. Here, a polymerizable group means a group having a polymerizable unsaturated double bond.

[0040] The monofunctional polymerizable compound described above is preferably a compound that has polymerizable unsaturated double bonds and is liquid at 25°C, with a molecular weight of 60 to 2000, and more preferably 100 to 1000. Furthermore, the viscosity of such monofunctional polymerizable compound is preferably 1000 mPa·s or less, and more preferably 300 mPa·s or less. The viscosity is preferably 1 mPa·s or more, and more preferably 3 mPa·s or more.

[0041] Other polymerizable compounds mentioned above, such as monofunctional polymerizable compounds, include polymerizable compounds having a heterocyclic structure and monovinyl ether compounds. Polymerizable compounds having a heterocyclic structure include N-vinylcaprolactam, N-vinylpyrrolidone, and N-vinylformamide.

[0042] Examples of monovinyl ether compounds include ethylene glycol monovinyl ether, triethylene glycol monovinyl ether, hydroxyethyl monovinyl ether, ethyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, octadecyl vinyl ether, cyclohexyl vinyl ether, hydroxybutyl vinyl ether, 2-ethylhexyl vinyl ether, hydroxynonyl monovinyl ether, cyclohexanedimethanol monovinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, isopropenyl vinyl ether, dodecyl vinyl ether, diethylene glycol monovinyl ether, phenyl glycidyl ether, butyl glycidyl ether, and 2-ethylhexyl glycidyl ether.

[0043] Other polymerizable compounds mentioned above, such as polyfunctional polymerizable compounds, include the following general formula (1): CH2=CR 5 -COO-R 6 -O-CH=CH-R 7 ...(1) (In the formula, R 5 R represents a hydrogen atom or a methyl group. 6R represents an organic residue with 2 to 20 carbon atoms. 7 ∫ represents a hydrogen atom or an organic residue having 1 to 11 carbon atoms. Examples include monomers represented by ∫ (hereinafter simply referred to as "monomer (1)"), divinyl ether compounds, trivinyl ether compounds, etc. In general formula (1), R 6 Examples of C2-C20 organic residues represented by include linear, branched, or cyclic alkylene groups with C2-C20, C2-C20 alkylene groups having oxygen atoms in their structure via ether and / or ester bonds, and C6-C11 aromatic groups in which hydrogen atoms bonded to carbon atoms constituting the ring may be substituted with other substituents. Preferably, C2-C6 alkylene groups and C2-C9 alkylene groups having oxygen atoms in their structure via ether bonds are used. R 7 Examples of C1-C11 organic residues represented by include C1-C10 linear, branched, or cyclic alkyl groups, C6-C11 aromatic groups in which hydrogen atoms bonded to carbon atoms constituting the ring may be substituted with other substituents, with C1-C2 alkyl groups and C6-C8 aromatic groups being preferred.

[0044] Specific examples of monomer (1) include (meth)acrylate 2-vinyloxyethyl, (meth)acrylate 3-vinyloxypropyl, (meth)acrylate 1-methyl-2-vinyloxyethyl, (meth)acrylate 2-vinyloxypropyl, (meth)acrylate 4-vinyloxybutyl, (meth)acrylate 1-methyl-3-vinyloxypropyl, (meth)acrylate 1-vinyloxymethylpropyl, (meth)acrylate 2-methyl-3-vinyloxypropyl, (meth)acrylate 3-methyl-3-vinyl Xypropyl, 1,1-dimethyl-2-vinyloxyethyl (meth)acrylate, 3-vinyloxybutyl (meth)acrylate, 1-methyl-2-vinyloxypropyl (meth)acrylate, 2-vinyloxybutyl (meth)acrylate, 4-vinyloxycyclohexyl (meth)acrylate, 5-vinyloxypentyl (meth)acrylate, 6-vinyloxyhexyl (meth)acrylate, 4-vinyloxymethylcyclohexylmethyl (meth)acrylate, p-vinyloxymethylphenyl (meth)acrylate Methyl, 2-(vinyloxyethoxy)ethyl (meth)acrylate, 2-(vinyloxyisopropoxy)ethyl (meth)acrylate, 2-(vinyloxyethoxy)propyl (meth)acrylate, 2-(vinyloxyethoxy)isopropyl (meth)acrylate, 2-(vinyloxyisopropoxy)propyl (meth)acrylate, 2-(vinyloxyisopropoxy)isopropyl (meth)acrylate, 2-(vinyloxyethoxyethoxy)ethyl (meth)acrylate Examples include 2-(vinyloxyethoxy)ethyl methacrylate, 2-(vinyloxyethoxyisopropoxy)propyl methacrylate, 2-(vinyloxyethoxyethoxy)isopropyl methacrylate, 2-(vinyloxyethoxyisopropoxy)isopropyl methacrylate, 2-(vinyloxyethoxyethoxyethoxy)ethyl methacrylate, polyethylene glycol monovinyl ether methacrylate, and polypropylene glycol monovinyl ether methacrylate. As monomer (1), 2-(2-vinyloxyethoxy)ethyl methacrylate is preferred, and 2-(2-vinyloxyethoxy)ethyl acrylate is more preferred, from the viewpoint of low viscosity, high flash point, and excellent curability.

[0045] Examples of divinyl ether compounds or trivinyl ether compounds include ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, propylene glycol divinyl ether, dipropylene glycol divinyl ether, butanediol divinyl ether, hexanediol divinyl ether, cyclohexanedimethanol divinyl ether, trimethylolpropane trivinyl ether, and the like.

[0046] If the curable composition of the present invention further contains other polymerizable compounds, one type of polymerizable compound may be used alone, or two or more types may be used in combination. Furthermore, if other polymerizable compounds are further contained, the content is preferably 30% by mass or less, more preferably 20% by mass or less, relative to the total curable composition of the present invention, and even more preferably 10% by mass or less, from the viewpoint of easily adjusting the viscosity of the resulting curable composition of the present invention and the curing shrinkage rate of the cured product of the curable composition of the present invention.

[0047] The curable composition of the present invention may be a curable composition that hardens by heat, or a curable composition that hardens by active energy rays. From the viewpoint of more suitable use as a black matrix forming material for micro-LEDs, as described later, it is preferable that the curable composition of the present invention is a curable composition that hardens by active energy rays. For this reason, the curable composition of the present invention may further contain a photopolymerization initiator (d), and it is preferable that it contains a photopolymerization initiator (d).

[0048] Examples of photopolymerization initiators (d) include 2-methylbenzoyl diphenylphosphine oxide, bis(2,6-dichlorobenzoyl)phenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, 2,6-dimethoxybenzoyl diphenylphosphine oxide, 2,6-dichlorobenzoyl diphenylphosphine oxide, and bis(2,6-dichlorobenzoyl)-2,5-di Acylphosphine compounds such as methylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-4-propylphenylphosphine oxide, bis(2,6-dichlorobenzoyl)-1-naphthylphosphine oxide, bis(2,6-dimethoxybenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, and bis(2,6-dimethoxybenzoyl)-2,5-dimethylphenylphosphine oxide; Phosphinic acid ester compounds such as (2,4,6-trimethylbenzoyl)phenylphosphinate methyl, (2,4,6-trimethylbenzoyl)phenylphosphinate ethyl, (3-benzoyl-2,4,6-trimethylbenzoyl)phenylphosphinate methyl, (3-benzoyl-2,4,6-trimethylbenzoyl)phenylphosphinate ethyl, and pivaloylphenylphosphinate isopropyl; Benzoin isobutyl ether, 2,4-diethylthioxanthone [also known as 2,4-diethylthioxanthene-9-one], 2-isopropylthioxanthone, methylbenzoyl formate, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 1-hydroxycyclohexylphenyl ketone, benzoin ethyl ether, benzyldimethyl ketal, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methyl Examples include propan-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, benzophenone, 4-phenylbenzophenone, isophthalphenone, 4-benzoyl-4'-methyldiphenyl sulfide, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-(4-morpholinophenyl)-butan-1-one), 1-{4-[(4-benzoylphenyl)sulfanyl]phenyl}-2-methyl-2-[(4-methylphenyl)sulfonyl]propan-1-one, etc.

[0049] Among these, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, (2,4,6-trimethylbenzoyl)phenylphosphine ethyl, and (3-benzoyl-2,4,6-trimethylbenzoyl)phenylphosphine ethyl are preferred, as they correspond to the wavelength of light emitted from an ultraviolet light-emitting diode (UV-LED) light source as the source of active energy rays. In particular, when using a UV-LED with a main peak wavelength of 365 to 405 nm as the light source, it is preferable to use an acylphosphine compound, especially phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide or (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, as the photopolymerization initiator.

[0050] Furthermore, it is preferable that the photopolymerization initiator (d) includes an oxime-based photopolymerization initiator. When the curable composition of the present invention includes an oxime-based photopolymerization initiator as the photopolymerization initiator (d), the resulting cured product tends to have excellent heat resistance and moisture resistance. Examples of oxime-based photopolymerization initiators include compounds described in the following publications: JCSPerkin II, 1979, pp. 1653-1660, JCSPerkin II, 1979, pp. 156-162, J. Photopolym. Sci. Tech., 1995, pp. 202-232, JP 2000-66385, JP 2000-80068, JP 2001-233842, JP 2004-534797, JP 2006-342166, JP 2007-269779, JP 2009-191061, and JP 2012-032556. In particular, oxime compounds are preferred if they are oxime-based photopolymerization initiators having a maximum absorption wavelength in the 350 nm to 500 nm wavelength range, and more preferably if they are oxime-based photopolymerization initiators having an absorption wavelength in the 360 ​​nm to 480 nm wavelength range. Commercially available oxime-based photopolymerization initiators can be used, such as "Irgacure OXE01," "Irgacure OXE02," "Irgacure OXE03," and "Irgacure OXE04" from BASF Japan, and "TR-PBG-304" from Changzhou Strong Electronic New Materials Co., Ltd.

[0051] The photopolymerization initiator (d) may contain one type alone or two or more types. When the curable composition of the present invention contains a photopolymerization initiator (d), its content is preferably 0.1 to 15% by mass, more preferably 0.5 to 12% by mass, and even more preferably 1.0 to 10% by mass, relative to the total curable composition of the present invention. When the content of the photopolymerization initiator (d) is within the above range, the curability and storage stability of the curable composition of the present invention tend to be good, and the performance of the formed cured product tends to improve.

[0052] If the curable composition of the present invention contains a photopolymerization initiator (d), the curable composition of the present invention may further contain a sensitizer. Examples of sensitizers include trimethylamine, methyldimethanolamine, triethanolamine, p-diethylaminoacetophenone, ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, N,N-dimethylbenzylamine, 4,4'-bis(diethylamino)benzophenone, anthracene-9,10-diethyl ether, and 9,10-bis(n-heptanoyloxy)anthracene. When the curable composition of the present invention contains a sensitizer, its content is preferably 0.1 to 10% by mass, and more preferably 0.5 to 8% by mass, relative to the total mass of the curable composition of the present invention. When the sensitizer content is within the above range, the curability of the curable composition of the present invention is good, and the performance of the formed cured product tends to improve.

[0053] In addition to the components described above, the curable composition of the present invention may further optionally contain polymerization inhibitors such as hydroquinone, di-t-butylhydroquinone, p-methoxyphenol, benzoquinone, dibutylhydroxytoluene, nitrosamine salts, hindered amine compounds, and 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO). If a polymerization inhibitor is included, the amount is preferably in the range of 0.01 to 2% by mass relative to the total amount of the curable composition of the present invention.

[0054] As described above, the curable composition of the present invention contains the dispersion of the present invention and a polymerizable compound (a2). In other words, the curable composition of the present invention contains a polymerizable compound (a1) derived from the components of the dispersion of the present invention, a colorant (b) and a dispersant (c) containing at least a bisbenzofuranone pigment, at least one polymerizable compound (a2) preferably having a hydroxyl group (meth)acrylate or a compound having two or more (meth)acrylate groups, more preferably a photopolymerization initiator (d), and the optional components mentioned above. The content of colorant (b) in the curable composition of the present invention can be controlled by the amount of dispersion liquid of the present invention used when preparing the curable composition of the present invention. The content of colorant (b) is preferably in the range of 1 to 50% by mass, and more preferably in the range of 10 to 40% by mass, relative to the total mass of the curable composition of the present invention. Furthermore, the average particle size (D50) of the bisbenzofuranone pigment in colorant (b) is preferably 50 to 500 nm, and more preferably 100 to 400 nm. When the content of colorant (b) in the curable composition of the present invention is within the above-mentioned range, the dispersibility of colorant (b) is excellent, and the storage stability and curability of the curable composition of the present invention are excellent. Furthermore, the cured product of the curable composition of the present invention exhibits excellent heat resistance, light resistance, moisture resistance, and adhesion to the substrate, and in particular, it tends to have excellent low light transmittance (opacity).

[0055] The curable composition of the present invention may further contain a surfactant in order to ensure ease of handling and ejection stability applicable to inkjet methods, and to set the surface tension within a desired range. Specific examples of the surfactant are the same as those that may be contained in the dispersion of the present invention. If the curable composition of the present invention further contains a surfactant, its content is preferably 0.05 to 1% by mass, and more preferably 0.1 to 0.8% by mass, relative to the total curable composition of the present invention.

[0056] The curable composition of the present invention may further contain a leveling agent. The leveling agent makes it easier to smooth the surface of the cured product formed from the curable composition, so that the cured product hardens more uniformly when irradiated with ultraviolet light, and thus less likely to develop irregularities on the cured product. Examples of leveling agents include silane compounds, fluorine compounds, acrylic copolymers, and alcohol alkoxylate compounds. Alternatively, the surfactants mentioned above can also be used as leveling agents.

[0057] The curable composition of the present invention may further contain additives such as ultraviolet absorbers, antioxidants, surface tension modifiers, fade inhibitors, and conductive salts. Furthermore, from the viewpoint of further improving adhesion to substrates such as plastic substrates, it may also contain non-reactive resins such as acrylic resins, epoxy resins, terpene phenolic resins, and rosin esters.

[0058] The viscosity of the curable composition of the present invention at 25°C is preferably in the range of 3 to 45 mPa·s, more preferably in the range of 3 to 30 mPa·s, and more preferably in the range of 5 to 25 mPa·s. Furthermore, the surface tension of the curable composition of the present invention is preferably in the range of 15 to 45 mN / m. Having the viscosity and surface tension of the curable composition of the present invention at 25°C within the above ranges is preferable from the viewpoint of improving the handling of the curable composition of the present invention and the inkjet ejection stability when molding by the inkjet method. Here, the curable composition of the present invention may further contain a solvent to adjust the viscosity and other properties as described above, as long as it does not impair the effects of the present invention, but it is preferable that it does not contain a solvent. If the composition does not contain a solvent, the drying step or heat treatment (annealing treatment) to remove the solvent can be omitted when curing the curable composition of the present invention, thereby simplifying the manufacturing process. In addition, the curability is good, outgassing from the solvent is less likely to occur from the cured product, and safety tends to be improved. Therefore, it is easy to obtain the curable composition of the present invention that can be applied by inkjet printing and does not require annealing treatment.

[0059] The curable composition of the present invention can be produced, for example, by using a conventional disperser such as a bead mill or stirrer to supply the dispersion of the present invention, a polymerizable compound (a2) [(meth)acrylate having a hydroxyl group, a compound having two or more (meth)acrylate groups, a (meth)acrylate having a phosphate group, a (meth)acrylate having a cyclic skeleton], a photopolymerization initiator (d), and various optional components as needed, and stirring and mixing. In addition to bead mills, various known and conventional dispersion machines can be used as dispersion machines, such as ultrasonic homogenizers, high-pressure homogenizers, paint shakers, ball mills, roll mills, sand mills, sand grinders, Dino mills, Dispermats, SC mills, and nanomizers.

[0060] As described above, the curable composition of the present invention is preferably a curable composition that hardens with active energy rays. Examples of active energy rays include visible light, ultraviolet light, infrared light, microwaves, EUV, semiconductor laser light, and excimer lasers (KrF, ArF). Among these active energy rays, the curable composition of the present invention is more preferably a curable composition that hardens by irradiation with light such as ultraviolet light. As light sources such as ultraviolet light, metal halide lamps, xenon lamps, carbon arc lamps, chemical lamps, low-pressure mercury lamps, high-pressure mercury lamps, and UV-LED lamps can be used. From the standpoint of generating very little heat and from the standpoint of environmental protection that can accommodate mercury-free materials, it is more preferable to cure the material by light irradiation using a UV-LED lamp, preferably a UV-LED lamp with a main peak wavelength of approximately 365-405 nm that can provide sufficient illumination. The irradiation energy of light using UV-LEDs is 50-5000 mJ / cm². 2 Preferably, it is within the range of 200-3000 mJ / cm². 2 A range is more preferable.

[0061] When the curable composition of the present invention is used, for example, as a black matrix for a light-emitting element, the method of formation is not particularly limited. For example, methods include: dropping the curable composition of the present invention between light-emitting elements, applying it via a spin coater, die coater, dispenser, inkjet method, stencil printing method, screen printing method, gravure printing method, or mask to preferably create a coating film of the same thickness as the light-emitting element, and then curing it; pre-injecting the curable composition of the present invention into a mold using, for example, a dispenser, transfer molding, or injection molding, and then immersing a lead frame or the like with the light-emitting element fixed therein before curing it; injecting the curable composition of the present invention into a mold into which the light-emitting element is inserted and curing it; or injecting the curable composition of the present invention into a cup or the like with a light-emitting element placed at the bottom using a dispenser or the like, and then curing it. In any of these methods, it is desirable to form the black matrix so as not to cover the upper surface of the light-emitting element in order to increase the light utilization efficiency.

[0062] In particular, molding using an inkjet method employing an inkjet recording system is preferred. In this case, droplets of the curable composition of the present invention can be accurately projected onto the target, thereby improving the accuracy of the shape and dimensions of the cured product. Furthermore, compared to molding using contact printing methods such as screen printing, when the curable composition of the present invention is molded using an inkjet method, foreign matter is less likely to be mixed into the curable composition and its cured product, and the yield is less likely to deteriorate when producing the black matrix of the light-emitting element. In the inkjet method, any conventionally known method can be used for ink ejection, such as a method that ejects droplets using the vibration of a piezoelectric element (a recording method using an inkjet head that forms ink droplets by the mechanical deformation of an electrostrictive element), a method that utilizes thermal energy, a method that uses an actuator that utilizes electrostatic force, or a method that uses a continuously ejecting charged control type head. Furthermore, when ejecting from the inkjet head, the curable composition of the present invention can be preheated to reduce its viscosity and then molded by the inkjet method.

[0063] The curable composition of the present invention can be preferably extruded and molded using an inkjet method, and then cured by irradiation with active energy rays, preferably ultraviolet light, to produce a cured product. The curable composition of the present invention is suitable as a material for forming the black layer on the upper part of the partition wall of light-emitting elements such as organic EL elements and LED elements, and as a composition for forming the black matrix of the aforementioned light-emitting elements. That is, one embodiment of the present invention is an LED element containing a cured product of the curable composition of the present invention. In particular, the curable composition of the present invention can be suitably used as a black matrix forming material for micro-LED elements. Furthermore, an electronic device using a cured product of the curable composition of the present invention is also an embodiment of the present invention. By using a cured product of the curable composition of the present invention, the accuracy of the dimensions and shape of the electronic device can be improved, and the physical properties of the cured product of the curable composition of the present invention can be exhibited. Examples of such electronic devices include displays, projectors, mobile terminals, watches, monitors, and other display devices, touch panels, or lighting using light-emitting elements such as LED elements, micro-LED elements, organic EL elements, and organic light-emitting elements (OLEDs); conductive films, organic semiconductor devices, solar cells, organic solar cells, organic photoreceptors (OPCs), organic transistors, and CMOS image sensors (CIS).

[0064] Furthermore, the applications of the curable composition of the present invention are not limited to the electronic devices described above. The curable composition of the present invention can be applied to the manufacture of various products that utilize its properties, and can be used, for example, as a forming material for black light-shielding areas such as picture frames of electronic devices, or as a forming material for filters that allow brightness adjustment, such as ND filters.

[0065] Figures 1 and 2 schematically show an example of the configuration of a microLED display, an electronic device using a cured product of the curable composition of the present invention, but the invention is not limited thereto. For example, the curable composition of the present invention can also be applied to displays such as those disclosed in U.S. Patent Registration No. 10978626. In Figure 1, the microLED display 100 comprises a substrate 2, a microLED element 1 installed on the substrate 2, a sealing material 3, a joint 4 between the microLED element 1 and a metal wiring portion (not shown) formed on the surface of the substrate 2, a partition wall 5, and a black layer 6 covering the upper part of the partition wall 5. The microLED display 100 comprises a plurality of microLED elements 1, and the plurality of microLED elements 1 are separated from adjacent microLED elements 1 on a substrate 2 by partition walls 5. The black layer 6 is a cured product of the curable composition of the present invention. For the substrate 2, for example, a transparent inorganic material such as glass, or a film made of a heat-resistant resin material such as polyethylene naphthalate, polyamide, or polyimide can be used. The thickness of the substrate 2 is not particularly limited, but from the viewpoint of balancing heat resistance, insulation, and manufacturing cost, a range of 25 to 125 μm is usually preferred for films. The thickness of the encapsulant 3 in the micro-LED display 100 is usually in the range of 5 to 100 μm, and more preferably in the range of 5 to 30 μm. By making the encapsulant 3 thinner, the micro-LED display 100 can be made thinner and flexible. The thickness of the encapsulant 3 refers to the distance from the outermost surface of the encapsulant 3 or the interface with the opposing substrate to the outermost surface on the other side or another opposing interface.

[0066] The microLED display 100 shown in Figure 1 can be manufactured, for example, as follows. First, a substrate 2 is prepared, and a plurality of microLED elements 1 are mounted on one surface of the substrate 2. Next, a precursor that will become a partition wall 5 is formed to a predetermined height between the plurality of microLED elements 1 on one surface of the substrate 2, for example, using a photosensitive material containing a white coloring agent, for example, by an inkjet method, and the partition wall 5 is produced by curing the precursor by irradiating it with ultraviolet light. Then, the curable composition of the present invention is applied to the partition wall 5, for example by an inkjet method, to produce a coating film, and then the coating film of the curable composition of the present invention is cured by irradiating it with ultraviolet light to produce a black layer 6. Then, a transparent sealing material is applied, for example by an inkjet method, to produce a coating film that covers the entire surface of the plurality of microLED elements 1, the partition wall 5 and the black layer 6, and then the coating film is cured by irradiating it with ultraviolet light to produce a sealing material 3. The ultraviolet irradiation in the above manufacturing process may be carried out in an oxygen-containing atmosphere such as air, or in an inert atmosphere such as a nitrogen atmosphere.

[0067] In Figure 2, the microLED display 100 comprises a substrate 2, a plurality of microLED elements 1 installed on the substrate 2, a junction 4 between the microLED elements 1 and a metal wiring portion (not shown) formed on the surface of the substrate 2, and a black layer 6 covering the microLED elements 1. The black layer 6 corresponds to a black matrix and is a cured product of the curable composition of the present invention. The manufacturing of the microLED display 100 shown in Figure 2 involves, for example, first preparing a substrate 2 and mounting a plurality of microLED elements 1 on one surface of the substrate 2. Next, the curable composition of the present invention is applied between the plurality of microLED elements 1, for example by an inkjet method, to create a coating film of the same thickness as the microLED elements. Then, the coating film of the curable composition of the present invention is cured by irradiating it with ultraviolet light to create a black layer 6 that completely covers the outer periphery of the plurality of microLED elements 1. This black layer 6 can enhance the contrast in electronic devices such as the microLED display 100. The irradiation of the coating film of the curable composition of the present invention with ultraviolet light may be carried out in an oxygen-containing atmosphere such as air, or in an inert atmosphere such as a nitrogen atmosphere.

[0068] Although an embodiment of the dispersion, curable composition, cured product of the curable composition of the present invention and a method for producing the same, an LED element containing the cured product, and an electronic device using the cured product have been described above, the present invention is not limited to the configuration of the embodiment described above. For example, the curable composition of the present invention may have additional other arbitrary configurations in the configuration of the above embodiment, or may be replaced with any arbitrary configuration that produces a similar effect. [Examples]

[0069] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples. The compounds used in this example are shown below.

[0070] <Polymerizable compound a1> a1-1: Light acrylate PO-A (product name, manufactured by Kyoeisha Chemical Co., Ltd., phenoxyethyl acrylate (monofunctional (meth)acrylate), viscosity (25℃) 8~20 mPa·s) a1-2: Miramer M1182 (product name, manufactured by MIWON, benzyl acrylate (monofunctional (meth)acrylate), viscosity (25℃) 1~10 mPa·s) a1-3: Viscoat 196 (product name, manufactured by Osaka Organic Chemical Industry Co., Ltd., 3,3,5-trimethylcyclohexyl acrylate (meth)acrylate with an alicyclic skeleton, viscosity (25℃) 1-10 mPa·s) <Coloring agent (b)> b-1: Lactone-based, Irgaphor Black S0100CF (BASF) Average particle diameter (D50) 250nm b-2: Carbon black, MA11 (manufactured by Mitsubishi Chemical Corporation), average particle size (D50) 29nm <Dispersant (c)> c-1: "EFKA(registered trademark)PX4701" (manufactured by BASF, acrylic block copolymer) c-2: "Solsperse (registered trademark) 39000" (manufactured by Lubrizol)

[0071] <Polymerizable compound a2> (Meth)acrylates with aromatic rings a2-1: Light acrylate PO-A (product name, manufactured by Kyoeisha Chemical Co., Ltd., phenoxyethyl acrylate (monofunctional (meth)acrylate), viscosity (25℃) 8~20 mPa·s) (Meth)acrylates containing a hydroxyl group a2-2:4-HBA (product name, manufactured by Osaka Organic Chemical Industry Co., Ltd., 4-hydroxybutyl acrylate, viscosity (25℃) 5.5 mPa·s) a2-3: HPA (product name, manufactured by Osaka Organic Chemical Industry Co., Ltd., hydroxypropyl acrylate), viscosity (25℃) 4 mPa·s) Compounds having two or more (meth)acrylate groups a2-4: Miramer M320 (product name, manufactured by MIWON, glycerin propylene oxide added triacrylate, viscosity (25℃) 80~120 mPa·s) a2-5: Miramer M3130 (product name, manufactured by MIWON, trimethylolpropaneethylene oxide modified triacrylate, viscosity (25℃) 50-70 mPa·s) a2-6: ARONIX M-405 (product name, manufactured by Toagosei Co., Ltd., dipentaerythritol penta and hexaacrylate, viscosity (25℃) 3700~5700 mPa·s) a2-7: Miramer M240 (product name, manufactured by MIWON, ethylene oxide-modified bisphenol A type diacrylate, viscosity (25℃) 900~1300 mPa·s) Other polymerizable monomers a2-8: EBECRYL80 (manufactured by Daicel Ornex; amine-modified highly reactive polyether acrylate, viscosity (25℃) ~3000 mPa·s) a2-9: EBECRYL7100 (manufactured by Daicel Ornex; aminoacrylate acrylate, viscosity (25℃) ~1200 mPa·s) a2-10: Viscoat 196 (product name, manufactured by Osaka Organic Chemical Industry Co., Ltd., 3,3,5-trimethylcyclohexyl acrylate (meth)acrylate with an alicyclic skeleton, viscosity (25℃) 1~10 mPa·s) a2-11: Isobornyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.; (meth)acrylate with an alicyclic skeleton, viscosity (25℃) ~15 mPa·s)

[0072] <Photopolymerization initiator> d-1: TPO-H [(2,4,6-trimethylbenzoyl)diphenylphosphine oxide; manufactured by IGM RESINS BV] d-2: Omnirad 819 [Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide; (Acylphosphine oxide system, manufactured by IGM RESINS BV)] d-3: Kayacure DETX-S [2,4-Diethylthioxanthene-9-one (manufactured by Nippon Kayaku Co., Ltd.)] d-4: Kayacure EPA [p-dimethylaminobenzoate ethyl (manufactured by Nippon Kayaku Co., Ltd.); sensitizer] d-5: Irgacure OXE01 (oxime-based photopolymerization initiator, manufactured by BASF Japan)

[0073] <Polymerization inhibitors> Nonflex Alba: 2,5-di-t-butylhydroquinone (manufactured by Seiko Chemical Co., Ltd.) <Additives (leveling agents)> KF-54: Polyether-modified polysiloxane (manufactured by Shin-Etsu Chemical Co., Ltd.) BYK-UV3500: Acrylic group-containing polyether-modified polydimethylsiloxane (manufactured by BYK)

[0074] 1. Preparation of the dispersion [Example 1-1] 76 parts by mass of polymerizable compound (a1-1), 20 parts by mass of coloring agent (b-1), and 4 parts by mass of dispersant (c-1) were placed in a bead mill and stirred to obtain dispersion X1. The viscosity of dispersion X1 at 25°C was measured using an E-type viscometer (TVE-25L: manufactured by Toki Sangyo Co., Ltd.) and was found to be 145 mPa·s. Furthermore, the D50 of the coloring agent (b-1) in dispersion X1 was 220-260 nm. [Example 1-2] Dispersion X2 was obtained in the same manner as in Example 1-1, except that polymerizable compound (a1-2) was used instead of polymerizable compound (a1-1). The viscosity of dispersion X2 at 25°C was measured in the same manner as in Example 1-1 and was found to be 34 mPa·s. Furthermore, the D50 of the coloring agent (b-1) in dispersion X2 was 307 nm. [Examples 1-3] 68 parts by mass of polymerizable compound (a1-1), 20 parts by mass of coloring agent (b-2), and 12 parts by mass of dispersant (c-2) were placed in a bead mill and stirred to obtain dispersion X3. The viscosity of dispersion X3 at 25°C was measured in the same manner as in Example 1-1 and was found to be 119 mPa·s. Furthermore, the D50 of the coloring agent (b-2) in dispersion X3 was 124 nm. [Examples 1-4] 70 parts by mass of polymerizable compound (a1-2), 25 parts by mass of coloring agent (b-1), and 5 parts by mass of dispersant (c-1) were placed in a bead mill and stirred to obtain dispersion X4. The viscosity of dispersion X4 at 25°C was measured using an E-type viscometer (TVE-25L: manufactured by Toki Sangyo Co., Ltd.) and was found to be 47 mPa·s. Furthermore, the D50 of the coloring agent (b-1) in dispersion X4 was 357 nm. The results of these Examples 1-1 to 1-4 are summarized in Table 1.

[0075] [Table 1] [Examples 1-5 to 1-7] Predetermined amounts of polymerizable compounds (a1-2), colorants (b-1), and dispersants (c-1) were placed in a bead mill and stirred and mixed, and the dispersibility was evaluated. The results are shown in Table 2. From the results of Examples 1-5 and 1-6, it can be concluded that if the concentration of the colorant is up to about 50% by mass, the dispersibility and viscosity of the resulting dispersion will not be problematic for actual use. On the other hand, in Example 1-7, the viscosity of the dispersion increased to an unmeasurable level, and the dispersibility of the colorant (b-1) was also not good.

[0076] [Table 2]

[0077] [Examples 1-8] When 76 parts by mass of polymerizable compound (a2-8), 20 parts by mass of coloring agent (b-1), and 4 parts by mass of dispersant (c-1) were placed in a bead mill and stirred, gelation occurred during mixing, and a dispersion with good dispersibility of coloring agent (b-1) could not be obtained.

[0078] [Examples 1-9 to 1-12] Polymerizable compounds (a1-2) and polymerizable compounds (a2-8) were mixed in predetermined ratios, and predetermined amounts of colorant (b-1) and dispersant (c-1) were added to a bead mill and stirred to evaluate the dispersibility. The results are shown in Table 3. From the results of Examples 1-4 and 1-9 to 1-10, it can be concluded that when the ratio of polymerizable compound (a1-2) to polymerizable compound (a2-8) is 1 / 0 to 1 / 6, the dispersibility is good and the viscosity is low, which does not interfere with actual use. From the results of Example 1-11, when the ratio of polymerizable compound (a1-2) to polymerizable compound (a2-8) is 1 / 9, although the dispersibility is good, an increase in viscosity was observed. Furthermore, the results from Example 1-12 showed that even though the ratio of polymerizable compounds (a1-2) to polymerizable compounds (a2-8) was 1 / 6, an increase in viscosity was observed with increasing concentration of colorant (b-1).

[0079] [Table 3]

[0080] 2. Preparation of curable composition [Example 2-1] 77 parts by mass of the dispersion X1 obtained in Example 1-1, 16.1 parts by mass of polymerizable compounds (a2), (a2-2), 5.0 parts by mass of (a2-4), and 4.1 parts by mass of (a2-8), 1.5 parts by mass of photopolymerization initiators (d), 3.8 parts by mass of (d-2), 2.0 parts by mass of (d-3), and 3.0 parts by mass of (d-4), 0.1 part by mass of polymerization inhibitor, and 0.1 part by mass of leveling agent were placed in a container and stirred to prepare curable composition 1. The mass ratio of each component of curable composition 1 is shown in Table 4 as a percentage. [Examples 2-2 to 2-13] The dispersions X2 to X8 obtained in Examples 1-2 to 1-8, polymerizable compound (a2), photopolymerization initiator (d), polymerization inhibitor, and leveling agent were placed in a container and stirred to prepare curable compositions 2 to 13 having the component content ratios shown in Tables 4 and 5. 3. Evaluation 3-1. Viscosity of curable compositions Viscosity was measured using an E-type viscometer (TVE-25L: manufactured by Toki Sangyo Co., Ltd.) at a temperature of 25°C. The viscosity of each curable composition is shown in Table 1 using the following evaluation index. [Evaluation metrics] A: It is 20 mPa·s or less. B: The pressure is greater than 20 mPa·s and less than or equal to 40 mPa·s. C: is above 40 mPa·s. Furthermore, when each curable composition was stored at -20 to 20°C, the viscosity change was small, and all of them exhibited good storage stability.

[0081] 3-2. Light transmittance of cured material (1) The curable compositions obtained in each example were coated onto an alkali-free glass substrate (35 mm long x 35 mm wide, 0.7 mm thick) using a spin coater to create a coating film with a thickness of approximately 5 μm. This coating film was then irradiated using a UV-LED device (manufactured by ITEC Systems Co., Ltd.) with a peak wavelength of 365 nm and a peak illuminance of 1000 mW / cm². 2 , cumulative light intensity 3 J / cm 2(1) The cured material (cured coating) was prepared by irradiating it with ultraviolet light under the specified conditions. (2) The light transmittance of each cured material obtained above at wavelengths of 400 to 800 nm was measured using a spectrometer (LCD-5200 manufactured by Otsuka Electronics Co., Ltd.). The measured value of the light transmittance of only the alkali-free glass substrate used during the preparation of the cured material was used as a reference value. All cured materials were nearly black. Table 1 shows the light transmittance values ​​at 550 nm for each cured material.

[0082] 3-3. Adhesion of the cured product In the same manner as in 3-2(1), cured products (cured coating films) of the curable compositions obtained in each manufacturing example were prepared, and cross-shaped cuts were made on their surface using a cutter. Next, adhesive tape (manufactured by Nichiban Co., Ltd.) was applied over the cross-shaped cuts and then peeled off. Furthermore, a new piece of adhesive tape was applied to the same cross-shaped cut as described above, and the process of peeling it off was repeated a total of five times. After each operation, the presence or absence of delamination of the cured coating from the alkali-free glass substrate was visually observed after the adhesive tape was removed, and the adhesion was evaluated as follows. [Evaluation Criteria] A: There was no peeling of the cured coating. B: After the third application, peeling of the hardened coating occurred. C: Peeling of the hardened coating was observed during the first and second applications.

[0083] 3-4. Heat resistance of the cured product In the same manner as in 3-2(1), cured products (cured coating films) of the curable compositions obtained in each manufacturing example were prepared. Each cured product was aged for 500 hours in a 120°C clean oven (manufactured by ESPEC), and the light transmittance after aging was measured using the procedure in 3-2. From the measurement results of the light transmittance spectrum, L * / a * / b * (=CIE LAB(L * a * b *The color space is calculated, and the difference ΔE[commonly used for color difference determination in CIE LAB] is calculated from the initial light transmittance (measured in 3-2) and the value after 500 hours of aging. ΔE * ab={(ΔL * ) 2 +(Δa * ) 2 +(Δb * ) 2} 1 / 2 The following calculations were performed, and the heat resistance was evaluated according to the evaluation criteria below. [Evaluation Criteria] A: 0 ≤ ΔE < 0.1 B: 0.1 ≤ ΔE < 0.3 C: 0.3 ≤ ΔE

[0084] 3-5. Lightfastness of the cured product In the same manner as in 3-2(1), cured products (cured coating films) of the curable compositions obtained in each manufacturing example were prepared and tested using a Suntest apparatus (ATLAS Material Testing Technology GmbH, CPS+, 765W / m²). 2 Each cured material was placed in a chamber (50°C) and irradiated with light equivalent to sunlight for 500 hours. The light transmittance after irradiation was measured using the procedure in 3-2, and ΔE was calculated from the difference in light transmittance before and after irradiation. Light resistance was evaluated according to the evaluation criteria below. The meaning of ΔE is the same as in 3-4. [Evaluation Criteria] A: 0 ≤ ΔE < 0.1 B: 0.1 ≤ ΔE < 0.3 C: 0.3 ≤ ΔE

[0085] 3-6. Moisture resistance of cured products In the same manner as in 3-2(1), cured products (cured coating films) were prepared from the curable compositions obtained in each manufacturing example, and each cured product was placed in a constant temperature bath at 85°C and 85% relative humidity for 500 hours. After removing the cured products and allowing them to cool naturally to 25°C, the presence or absence of surface non-uniformity was observed using a microscope (magnification 100x), and the moisture resistance was evaluated according to the following criteria. [Evaluation Criteria] A: No change B: Microscopic observation at 100x magnification reveals non-uniformity on the surface of the hardened material. C: Non-uniformity of the hardened surface can be confirmed visually without the need for microscopic observation.

[0086] The mass ratio of each component in each curable composition, and the evaluation results described above, are summarized in Tables 4 and 5. Additionally, the proportion of compounds having two or more (meth)acrylate groups relative to the total mass of the curable composition (polyfunctional compound ratio; mass%) and the proportion of photopolymerization initiator (d) relative to the total mass of the curable composition (photopolymerization initiator (d) ratio; mass%) are also shown in Tables 4 and 5.

[0087] [Table 4]

[0088] [Table 5]

[0089] These results indicate that a curable composition containing a polymerizable compound (a1), a bisbenzofuranone pigment as a colorant (b), and a dispersant (c), with a polymerizable compound (a2) containing a (meth)acrylate having a hydroxyl group and a compound having two or more (meth)acrylate groups, and preferably containing a predetermined amount or more of a photopolymerization initiator, has low viscosity, is easy to handle, has excellent storage stability, and exhibits excellent curability, adhesion to the substrate, heat resistance, light resistance, and moisture resistance of the cured product. In particular, the light transmittance of the cured product at a film thickness of approximately 5 μm is in the range of 0.1 to 1.0%, indicating excellent low light transmittance (opacity). Furthermore, the transmitted light of a cured film made from such a curable composition of the present invention has a color close to neutral, making it suitable as a black matrix material. On the other hand, curable compositions consisting of a dispersion in which the black component is carbon black (Examples 2-3) show that carbon black has lower UV transmittance than bisbenzofuranone pigments, and therefore tend to have insufficient curability with UV irradiation alone compared to the curable compositions of the present invention, resulting in inferior adhesion and moisture resistance of the cured product. Furthermore, the transmitted light from the cured film made from the curable composition of Example 2-3 is slightly yellowish to reddish. [Industrial applicability]

[0090] The curable composition of the present invention exhibits excellent curability, enabling the formation of molded products by inkjet printing, and the resulting cured products have excellent heat resistance, light resistance, moisture resistance, and low light transmittance (opacity). The curable composition of the present invention is particularly suitable as a black matrix forming material for light-emitting elements and is useful as a light-shielding (opacity) material for micro-LED elements. Furthermore, electronic devices using cured products of the curable composition of the present invention are useful as various display devices, touch panels or lighting; conductive films, organic semiconductor devices, solar cells, organic solar cells, organic photoreceptors (OPCs), organic transistors, CMOS image sensors (CIS), etc. [Explanation of Symbols]

[0091] 1 Micro LED element 2 circuit boards 3. Sealing material 4 Joint 5 Bulkhead 6 Black layer 100 MicroLED displays

Claims

1. A dispersion comprising a polymerizable compound (a1), a coloring agent (b), and a dispersant (c), wherein the polymerizable compound (a1) contains a monofunctional (meth)acrylate having a viscosity of 30 mPa·s or less at 25°C, and the content of the polymerizable compound (a1) in the total dispersion is in the range of 40 to 85% by mass, and the coloring agent (b) contains at least a bisbenzofuranone pigment, and the content of the coloring agent (b) in the total dispersion is in the range of 10 to 40% by mass, and the dispersion does not contain a solvent.

2. The dispersion according to claim 1, wherein the monofunctional (meth)acrylate is a monofunctional (meth)acrylate having an aromatic ring.

3. The dispersion according to claim 1, wherein the average particle size (D50) of the bisbenzofuranone pigment in the coloring agent (b) is 50 to 500 nm.

4. A curable composition comprising the dispersion described in claim 1 and a polymerizable compound (a2), and free from solvents.

5. The curable composition according to claim 4, wherein the polymerizable compound (a2) contains a (meth)acrylate having a hydroxyl group.

6. The curable composition according to claim 4, wherein the polymerizable compound (a2) contains a compound having two or more (meth)acrylate groups.

7. Furthermore, the curable composition according to claim 4, comprising a photopolymerization initiator (d).

8. The curable composition according to claim 7, wherein the photopolymerization initiator (d) comprises an oxime-based photopolymerization initiator.

9. The curable composition according to claim 4, wherein the content of the coloring agent (b) is 10 to 40% by mass with respect to the total mass of the curable composition.

10. The curable composition according to claim 4, wherein the average particle size (D50) of the bisbenzofuranone pigment in the coloring agent (b) is 50 to 500 nm.

11. The curable composition according to claim 4, which is an active energy ray curable composition.

12. The curable composition according to claim 4, wherein the viscosity at 25°C is 3 to 30 mPa·s.

13. A cured product of a curable composition according to any one of claims 4 to 12.

14. A method for producing a cured product, comprising the step of curing a curable composition according to any one of claims 4 to 12 by irradiating it with an active energy ray.

15. The manufacturing method according to claim 14, wherein the curable composition is molded by an inkjet method.

16. An electronic device using a cured product of a curable composition according to any one of claims 4 to 12.

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