Dispersion, curable composition, cured product thereof, and electronic device

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

Dispersion, curable composition, cured product thereof, and electronic device

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

[0002] Display devices such as liquid crystal displays, plasma displays, organic electroluminescence (EL) displays, and mini-LED displays are widely used. In recent years, active development has been underway toward the practical application of micro-LED displays, which offer excellent properties such as brightness, color gamut, contrast, and reliability, and can achieve low power consumption by using high-luminous efficiency LEDs as light sources. Various materials for forming light-blocking layers (black matrices) that do not transmit light have been continuously developed in order to maintain the characteristics of light-emitting elements and improve image quality and contrast. A black matrix forming material for color liquid crystal displays was previously disclosed, which contains a black pigment that is a mixture of at least two materials, including a photopolymerizable compound, a photopolymerization initiator, an alkali-soluble resin, resin-coated carbon black, and a metal oxide (see Patent Document 1). More recently, Patent Document 2 discloses a photosensitive resin composition containing 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-blocking agent containing dye-coated carbon black. The composition is said to be capable of forming a black matrix that has high resistance and optical density and is resistant to deformation due to heating. Patent Document 3 discloses a photosensitive resin composition containing an alkali-soluble resin including a novolac resin, a photopolymerizable compound including a specific dendritic polymer, a photopolymerization initiator, and carbon black, which is resistant to excessive flow when heated and is capable of forming a colored cured film finely patterned to a desired size, and is suitable for forming black matrices or black column spacers in liquid crystal display panels and for forming banks for dividing light-emitting layers in organic EL elements. Patent Document 4 discloses a photosensitive coloring composition for forming colored spacers, which contains a colorant containing specific amounts of organic pigment and carbon black, an alkali-soluble resin, a photopolymerization initiator, an ethylenically unsaturated compound, a solvent, and a dispersant, and which has a specified maximum transmittance at a specific wavelength. The composition is said to have high light-blocking properties, control the step between the main spacer and the sub-spacer, and suppress light leakage in the visible range.Patent Document 5 discloses a photosensitive resin composition for black resist containing an alkali-soluble resin of a specific structure, a photopolymerizable compound having at least two ethylenically unsaturated bonds, an oxime ester photopolymerization initiator, carbon black, a specific coupling agent, a specific surfactant in predetermined amounts, and a solvent, which is said to be capable of forming a high-definition black matrix with low reflectance, and when partition walls are formed with a film thickness of 2 μm or more, it is possible to impart the pattern cross-sectional shape and ink-repellent surface properties required for the partition walls. Patent Document 6 discloses a photosensitive resin composition for black resist containing an unsaturated group-containing alkali-soluble resin, a photopolymerizable compound having at least two unsaturated bonds, a photopolymerization initiator, carbon black whose surface is coated with a dye, and aluminum oxide fine particles with a specific refractive index, which is said to have both high light-shielding properties and low reflectance, and to enable the formation of high-definition patterns without jagged edges.

[0003] JP 2000-147240 A JP 2017-198918 A JP 2018-013716 A JP 2021-192120 A JP 2022-173086 A JP 2023-051765 A

[0004] Existing black matrix forming materials such as those described in Patent Documents 1 to 6 use carbon black as a black material and therefore have poor UV curability, necessitating the combined use of a pre-cure (drying) process, a UV curing process, and a heat curing process (post-baking heating). Furthermore, because a photolithographic etching process may also be required, the manufacturing process tends to be cumbersome and energy consumption increases, leaving room for further improvement. Meanwhile, with regard to the composition itself as a black matrix forming material to be applied to electronic devices using light-emitting elements such as LEDs, there is a demand for a solvent-free composition that can be applied by inkjet printing and does not require annealing treatment, from the viewpoints of not only the manufacturing cost of the compounds to be blended, but also environmental considerations, support for thinner displays, simplification of the manufacturing process, and improved safety.

[0005]

[0009] As a result of extensive research, the present inventors have found that dispersions containing a specific colorant and polymerizable compound as constituent components have excellent dispersibility and storage stability, that curable compositions prepared from such dispersions have excellent curability and can be formed into molded articles by an inkjet method, and that the resulting cured articles have excellent physical properties such as heat resistance, light resistance, moisture resistance, and low light transmittance in the visible range (hiding performance), and are useful as black component materials for electronic devices having light-emitting elements such as LED elements.

[0010] An object of the present invention is to provide a curable composition that has excellent curability and storage stability and can be used to form cured articles by an inkjet method that have excellent heat resistance, light resistance, moisture resistance, low light transmittance in the visible range (hiding performance), and adhesion to substrates.

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

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

[11] The curable composition of any one of [6] to

[10] , wherein the content of the colorant (b) is 1 to 50 mass% based on the total mass of the curable composition.

[12] The curable composition of any one of [6] to

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

[13] The curable composition of any one of [6] to

[12] , which is an active energy ray-curable composition.

[14] The curable composition of any one of [6] to

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

[15] The curable composition of any one of [6] to

[14] , which does not contain a solvent.

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

[15] .

[17] A method for producing a cured product, comprising a step of curing the curable composition of any one of [6] to

[15] by irradiating it with active energy rays.

[18] The manufacturing method of

[17] , wherein the curable composition is molded by an ink-jet method.

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

[15] .

[0007] According to the present invention, there can be provided a curable composition which can be used to form a cured product by an inkjet method, which has excellent curability and storage stability, as well as excellent heat resistance, light resistance, moisture resistance, low light transmittance in the visible region (hiding performance), and adhesion to a substrate.

[0008] 1 is a diagram schematically illustrating an example of the configuration of a micro LED display as an embodiment of an electronic device using a cured product of the curable composition of the present invention as a black layer on top of a wall material, and FIG. 2 is a diagram schematically illustrating an example of the configuration of a micro LED display as an embodiment of an electronic device using a cured product of the curable composition of the present invention as a black matrix.

[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) relative to the entire dispersion is in the range of 1 to 50 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 containing the above-mentioned dispersion and a polymerizable compound (a2) (hereinafter simply referred to as the "curable composition of the present invention"). Note that, in this specification, a composition containing the dispersion of the present invention, the polymerizable compound (a2), and various components described below is referred to as the "curable composition." In this specification, "(meth)acrylate" is a term that collectively refers to acrylate, methacrylate, and both. "(Meth)acrylic" is a term that collectively refers to acrylic, methacrylic, and both. The term "(meth)acryloyloxy group" is a general term that refers to an acryloyloxy group, a methacryloyloxy group, or both.

[0010] The dispersion of the present invention has excellent dispersibility of the colorant (b) and excellent storage stability. The curable composition of the present invention contains the dispersion of the present invention as a constituent component and has excellent curability and storage stability. Furthermore, from the curable composition of the present invention, a cured product having excellent heat resistance, light resistance, moisture resistance, low light transmittance in the visible region (hiding performance), and adhesion to a substrate can be formed by an inkjet method. First, the composition of the dispersion 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 and a low viscosity, making it easy to handle.

[0012] The polymerizable compound (a1) preferably contains a monofunctional (meth)acrylate. The inclusion of a monofunctional (meth)acrylate facilitates reducing the viscosity of the dispersion of the present invention and the curable composition of the present invention, described below, which contains the dispersion of the present invention as a constituent component. In the dispersion of the present invention, the monofunctional (meth)acrylate is preferably a monofunctional (meth)acrylate having an aromatic ring, such as 2-phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, m-phenoxybenzyl (meth)acrylate, 1-naphthalenemethyl (meth)acrylate, methylphenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, or phenoxy(polyethylene glycol) (meth)acrylate. The 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 having an aromatic ring facilitates further improving 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 having an aromatic ring as the polymerizable compound (a1) increases the affinity between the two and improves solubility, making it easier to reduce the viscosity of the resulting dispersion. The polymerizable compound (a1) is preferably composed of the above-mentioned monofunctional (meth)acrylate having an aromatic ring, within a range that maintains the viscosity of the dispersion of the present invention and the dispersibility of the colorant (b), and may contain a monofunctional (meth)acrylate having an aromatic ring and a compound having two or more (meth)acrylate groups that can constitute the curable composition of the present invention described below. Furthermore, the polymerizable compound (a1) may contain, together with the above-mentioned monofunctional (meth)acrylate having an aromatic ring, another monofunctional (meth)acrylate that does not have an aromatic ring. It is particularly preferable to contain a monofunctional (meth)acrylate having an alicyclic ring. In terms of realizing low viscosity and good solubility, it is preferable that the polymerizable compound in the dispersion of the present invention contains a monofunctional (meth)acrylate having an aromatic ring in an amount of 5% by mass or more, and more preferably 10% by mass or more.The content of the 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 than carbon black. Therefore, it is presumed that the use of a colorant (b) containing at least a bisbenzofuranone pigment significantly improves curability with 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 below, containing the dispersion of the present invention exhibits good curability, and it is believed that the light resistance and low light transmittance (hiding performance) in the visible range of the resulting cured product can be improved. The content of colorant (b) relative to the total dispersion of the present invention is in the range of 1 to 50% by mass, preferably 5 to 45% by mass, more preferably 10 to 40% by mass, and even more preferably 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 maintained well. Furthermore, the curability of the curable composition of the present invention, the light resistance of the cured product of the curable composition of the present invention, and the low light transmittance (hiding performance) in the visible light region, which will be described later, can be improved. The bisbenzofuranone pigment may have a structure represented by the following general formulas (I) to (IV), or an isomer or tautomer thereof. For example, the general formulas (I) to (III) are each in a cis-trans isomer relationship, and the pigment may have two or more of these structures.

[0014]

[0015] In the formula, R １ and R ２ R each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. ３ and R ４ are each independently R １０ , OR １１ , S.R. １１ , C.O.R. １１ , C.O.R. １１ R １２, N.R. １１ COR １２ , O.C.O.R. １１ , COOR １１ , SCOR １１ , OCSR １１ , COSR １１ , CSR １１ , CN, a halogen atom or a hydroxyl group. 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 represents 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 from 0 to 4. Bisbenzofuranone pigments having a structure represented by any of the above general formulas (I) to (IV) are known and can be obtained, for example, by the method described in JP-A No. 2012-515233 or the method described in Example 12b of WO 2000 / 024736. Commercially available bisbenzofuranone pigments can also be used, such as "Irgaphor (registered trademark) Black S 0100CF" (trade name) manufactured by BASF.

[0016] The average particle diameter (D50) of the bisbenzofuranone pigment in colorant (b) is preferably 50 to 500 nm, more preferably 100 to 400 nm, and even more preferably 150 to 350 nm. When the average particle diameter (D50) of the bisbenzofuranone pigment is 50 nm or more, the curable composition of the present invention (described below) containing the dispersion of the present invention becomes easier to handle, and nozzle clogging and other problems are less likely to occur when an inkjet method is applied. Furthermore, the light transmittance of the cured product of the curable composition of the present invention can be sufficiently reduced, and hiding performance can be maintained. The average particle diameter (D50) is the cumulative 50% diameter on a volume basis, and is determined by a laser diffraction / scattering method.

[0017] The dispersion of the present invention may further contain other colorants in addition to the bisbenzofuranone pigment as colorant (b), as long as the effects of the present invention are not impaired. 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, threne pigments, and metal complex pigments. Examples of inorganic pigments include titanium oxide, zinc oxide, zinc sulfide, white lead, calcium carbonate, precipitated barium sulfate, white carbon, alumina white, kaolin clay, talc, bentonite, black iron oxide, cadmium red, red iron oxide, molybdenum red, molybdate orange, chrome vermilion, yellow lead, cadmium yellow, yellow iron oxide, titanium yellow, chromium oxide, viridian, titanium cobalt green, cobalt green, cobalt chrome green, Victoria green, ultramarine, Prussian 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] Examples of black colorants include black organic pigments such as carbon black, perylene black, aniline black, and benzofuranone-based pigments; mixed-color organic pigments obtained by mixing two or more pigments having colors such as red, blue, green, purple, yellow, magenta, and cyan to produce pseudo-black colors; 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. One type of other colorant may be used together with the bisbenzofuranone-based pigment, or two or more types may be used together with the bisbenzofuranone-based pigment. Among these, phthalocyanine-based pigments are preferred, and copper phthalocyanine-based pigments are more preferred, from the viewpoint of further improving the low light transmittance (hiding performance), heat resistance, and moisture resistance in the visible light region of the curable composition of the present invention, as described below. An example of a copper phthalocyanine pigment is "FASTOGEN BLUE AE8" (trade name; equivalent to pigment PB15:6) manufactured by Toyo Ink Co., Ltd. When a colorant other than the bisbenzofuranone pigment is contained as colorant (b), the amount of the other colorant is preferably in the range of 1 to 75% by mass, more preferably in the range of 5 to 30% by mass, based on the content of the bisbenzofuranone pigment.

[0019] The dispersant (c) is used in the dispersion of the present invention for the purpose of further improving the dispersion stability of the colorant (b) in the polymerizable compound (a1). As the dispersant (c), a polymer dispersant having both a pigment-affinity group that chemically bonds to or adsorbs to the pigment surface and a polymer chain or group that is solvent-philic is preferred. The polymer dispersant improves the pigment's wettability to the dispersion medium, promoting deagglomeration of the pigment, stabilizing the pigment particle size and viscosity through its steric hindrance and electrostatic repulsion effects, and further improving the viscosity reduction and storage stability of the dispersion of the present invention or the curable composition of the present invention described below. Examples of polymer dispersants include polyester-based, acrylic-based, polyurethane-based, polyallylamine-based, carbodiimide-based, and polyamide-based dispersants. Commercially available products can be used as the dispersant (c), for example, Ajinomoto Fine-Techno Co., Ltd.'s Ajisper (Ajisper is a registered trademark) PB821, PB822, PB824; Lubrizol's Solsperse (Solsperse is a registered trademark) 24000GR, 32000, 33000, 39000, S86000; Kusumoto Chemicals Co., Ltd.'s Disparlon DA-703-50; BASF's EFKA (EFKA is a registered trademark) PX4701, PX4703; BYK's BYK2013, BYK9151, and the like. The amount of dispersant (c) used is preferably in the range of 10 to 100% by mass relative to the colorant (b). From the viewpoint of achieving better inkjet ejection stability and dispersibility of colorant (b) in the curable composition of the present invention described below, a range of 15 to 60% by mass is more preferred. A synergist may also be added to enhance the effect of the polymeric dispersant stabilizing phthalocyanine blue and green, organic violet pigments, and the like. 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 or hydrophobic interactions, modifying the pigment surface to be acidic or basic, thereby increasing the electrostatic repulsion between pigment particles and improving dispersion stability. Furthermore, the electrostatic adsorption force with the solvent-philic portion of the dispersant is enhanced, allowing the dispersant to be firmly adsorbed to the pigment surface via the synergist, further improving dispersion stability.Such synergists may be commercially available products, such as BYK-SYNERGIST 2100 manufactured by BYK, and Solsperse (Solsperse is a registered trademark) 5000 and 5000S Synergist manufactured by Lubrizol.

[0020] The dispersion of the present invention may further contain a surfactant from the viewpoint of improving the handling property and dispersibility of the colorant (b), the discharge stability of the curable composition of the present invention described later, and the wettability to the substrate. Examples of the surfactant include anionic surfactants such as dialkyl sulfosuccinates, alkyl naphthalene 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; compounds having a silicone chain, silicone surfactants having a polymer chain such as a silicone chain and a poly(meth)acrylate chain, silicone surfactants having a polyether chain at the side chain or end and a polysiloxane structure in the main chain; fluorine-based surfactants having a perfluoroalkyl chain, oily fluorine-based compounds (e.g., fluorine oils), and solid fluorine compound resins (e.g., tetrafluoroethylene resins), preferably hydrophobic organic fluorocompounds. These are commercially available products such as the "Megafac (registered trademark)" series manufactured by DIC Corporation, the "Ftergent (registered trademark)" series manufactured by Neos Corporation, the "BYK (registered trademark)" series manufactured by BYK Corporation, the "TEGO (registered trademark) Rad" series manufactured by Evonik Corporation, the "DISPARLON (registered trademark) OX" series manufactured by Kusumoto Chemicals Co., Ltd., and "Polyflow No. 7," "Florene AC-300," and "Florene AC-303" manufactured by Kyoeisha Chemical Co., Ltd. When the dispersion of the present invention contains a surfactant, the amount thereof is preferably 0.05 to 1 mass %, and more preferably 0.1 to 0.8 mass %, based on the total mass of the dispersion of the present invention.

[0021] The dispersion of the present invention is characterized by not containing a solvent. In this specification, the term "solvent" refers to a compound that dissolves the polymerizable compound (a1), the dispersant (c), and the polymerizable compound (a2) and the photopolymerization initiator (d) described below, but does not react with these components. Examples of such solvents include ethers such as 3-methoxy-1-butanol, 3-methoxy-3-methylbutanol, tetrahydrofuran, tetrahydropyran, 1,4-dioxane, anisole, and phenetole; 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-methoxypropionate, methyl 2-ethoxypropionate, ethyl 2-ethoxypropionate, 3-methoxybutyl acetate, and 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;Examples of suitable solvents include 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; and aromatic hydrocarbons such as benzene, toluene, and xylene. Furthermore, the phrase "solvent-free" used herein means that the solvent content in the dispersion of the present invention is 1% by mass or less. The content of the solvent is preferably 0.5% by mass or less, more preferably 0.1% by mass or less. The dispersion of the present invention can well disperse the colorant (b) containing at least a bisbenzofuranone pigment, even without containing a solvent, and has excellent storage stability. Therefore, the production process of the dispersion of the present invention can be simplified, and handling safety can be improved. Furthermore, the curable composition of the present invention described below can be applied by an inkjet method, and annealing treatment during curing is not required.

[0022] The dispersion of the present invention can be produced by using a conventional dispersing machine such as a bead mill or a stirrer to supply the polymerizable compound (a1), colorant (b), and dispersant (c), and then stirring and mixing to disperse the colorant (b). When a bead mill is used, glass beads or zirconia beads can be used as the beads. Here, as the dispersing machine, various known and commonly used dispersing machines can be used, such as a bead mill, an ultrasonic homogenizer, a high-pressure homogenizer, a paint shaker, a ball mill, a roll mill, a sand mill, a sand grinder, a Dyno Mill, a Dispermat, an SC Mill, a Nanomizer, etc.

[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 hydroxy group as the polymerizable compound (a2). Examples of the (meth)acrylate having a hydroxy 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 hydroxy group may be used alone, or two or more may be used in combination. Among these, 2-hydroxypropyl(meth)acrylate and 4-hydroxybutyl(meth)acrylate are preferred, and 4-hydroxybutyl(meth)acrylate is more preferred, from the viewpoints of being versatile, relatively inexpensive, and providing good curability, inkjet ejection properties, and excellent physical properties such as moisture resistance and heat resistance of the cured product after curing. When the polymerizable compound (a2) contains a (meth)acrylate having a hydroxy group, the moisture resistance, heat resistance, and adhesion to a substrate of the cured product formed from the curable composition of the present invention are improved.

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

[0025] The curable composition of the present invention preferably contains, as the polymerizable compound (a2), a compound having two or more (meth)acrylate groups. Examples of the compound 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, tricyclodecane dimethanol di(meth)acrylate, ethoxylated (2) neopentyl glycol di(meth)acrylate [a compound obtained by di(meth)acrylating a neopentyl glycol ethylene oxide 2-mol adduct], propoxylated (2) neopentyl glycol di(meth)acrylate [a compound obtained by di(meth)acrylating a neopentyl glycol propylene oxide 2-mol adduct], and hydroxypivalic acid neopentyl glycol di(meth)acrylate;

[0026] Alkylene glycol di(meth)acrylates such as 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, and bis(4-acryloxypolyethoxyphenyl)propane; di(meth)acrylate of tris(2-hydroxyethyl)isocyanurate; dimethyloltricyclodecane di(meth)acrylate, and caprolactone-modified hydroxypivalic acid neopentyl glycol di(meth)acrylate; trifunctional (meth)acrylates such as bisphenol A di(meth)acrylate, propylene oxide-modified bisphenol A di(meth)acrylate, ethylene oxide-modified bisphenol A di(meth)acrylate, bisphenol F di(meth)acrylate, propylene oxide-modified bisphenol F di(meth)acrylate, and ethylene oxide-modified bisphenol F 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, propylene oxide adduct tri(meth)acrylate of glycerin, and ethylene oxide adduct tri(meth)acrylate of glycerin; Examples of the acrylate include tetrafunctional (meth)acrylates such as pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, and tetramethylolmethane tetra(meth)acrylate; and hexafunctional (meth)acrylates such as dipentaerythritol hexa(meth)acrylate and caprolactone-modified dipentaerythritol hexa(meth)acrylate.

[0027] Furthermore, urethane (meth)acrylate and amino (meth)acrylate can also be used as compounds having two or more (meth)acrylate groups. Urethane (meth)acrylate and amino (meth)acrylate may be any of a monomer, oligomer, and polymer. In this specification, "monomer" refers to a compound having a molecular weight (weight average molecular weight if the molecular weight is distributed) of 1,000 or less. The molecular weight of the monomer (weight average molecular weight if the molecular weight is distributed) is 50 to 1,000. "Oligomer" generally refers to a polymer having a finite number of monomer-based structural units (generally 5 to 100) and a weight average molecular weight greater than 1,000 and less than 30,000. "Polymer" refers to a polymer having a weight average molecular weight of 30,000 or more. The weight average molecular weight is measured by gel permeation chromatography (GPC) and calculated as a standard polystyrene equivalent value.

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

[0029] The amino(meth)acrylate is an amine-modified (meth)acrylate having an amino group. The number average molecular weight of the amino(meth)acrylate is preferably 500 to 20,000, more preferably 600 to 10,000, and even more preferably 800 to 5,000. Commercially available amino(meth)acrylates can also be used, such as EBECRYL7100 and EBECRYL80 manufactured by Daicel-Allnex Corporation and CN551 manufactured by ARKEMA (manufactured by Sartomer).

[0030] The compound having two or more (meth)acrylate groups may be used alone or in combination of two or more. The content of the compound 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 mass%, more preferably in the range of 1 to 15 mass%, and even more preferably in the range of 2 to 12 mass%, relative to the total mass of the curable composition of the present invention. When the curable composition of the present invention contains the compound having two or more (meth)acrylate groups in such a range, the curability of the curable composition of the present invention is improved, and further, the performance of the cured product formed from the curable composition of the present invention, such as flexibility and adhesion to a substrate, is improved. Furthermore, when one type of compound is used alone as the compound having two or more (meth)acrylate groups, for example, when a compound having three or more (meth)acrylate groups such as the above-exemplified trifunctional (meth)acrylates or tetrafunctional (meth)acrylates, such as trimethylolpropane ethylene oxide-modified triacrylate, is used, the hardness of the cured product formed from the curable composition of the present invention can be increased, and the heat resistance and moisture resistance can also be effectively improved.

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

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

[0033] Commercially available (meth)acrylates having a phosphate group can also be used, and examples thereof include those manufactured by Daicel-Allnex Co., Ltd. under the product name "EBECRYL168," and those manufactured by Nippon Kayaku Co., Ltd. under the product names "KAYAMER PM-2" and "KAYAMER PM-21," manufactured by Unichemical Co., Ltd. under the product names "Phosmer M," "Phosmer PE," and "Phosmer PP," manufactured by Kyoeisha Chemical Co., Ltd. under the product names "Light Ester P-1M," "Light Acrylate P-1A(N)," and "Light Ester P-2M," manufactured by Kyoeisha Chemical Co., Ltd., and "JPA-514" manufactured by Johoku Chemical Industry Co., Ltd.

[0034] The (meth)acrylate having a phosphate group may be used alone or in combination of two or more. When the curable composition of the present invention contains a (meth)acrylate having a phosphate group as the polymerizable compound (a2), the amount thereof is preferably in the range of 0.1 to 10 mass%, more preferably in the range of 0.2 to 8 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 in such a range, the curability of the curable composition of the present invention is improved, and further, the performance of the cured product formed from the curable composition of the present invention, such as adhesion to a substrate, is 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 described above in connection with the polymerizable compound (a1). Examples of (meth)acrylates having a cyclic skeleton containing a heteroatom include (meth)acryloylmorpholine, N-(meth)acryloyloxyethylhexahydrophthalimide, tetrahydrofurfuryl (meth)acrylate, and cyclic trimethylolpropane formal (meth)acrylate. Commercially available (meth)acrylates having a cyclic skeleton containing a heteroatom can also be used, and examples thereof include products under the names "Viscoat 150" and "Viscoat 200" manufactured by Osaka Organic Chemical Industry Ltd. Examples of the (meth)acrylate having an alicyclic skeleton include monofunctional (meth)acrylates having a cyclic aliphatic group, such as cyclohexyl (meth)acrylate, 4-t-butylcyclohexyl (meth)acrylate, tricyclodecane dimethanol mono(meth)acrylate, adamantyl (meth)acrylate, cyclohexane dimethanol 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. The inclusion of 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 when molding by an inkjet method. Furthermore, the cured product formed from the curable composition of the present invention exhibits reduced shrinkage and excellent adhesion. In this specification, a (meth)acrylate having a hydroxyl group and a cyclic skeleton is classified as a (meth)acrylate having a hydroxyl group, and a (meth)acrylate having a phosphate group and a cyclic skeleton is classified as a (meth)acrylate having a phosphate group. Furthermore, a monomer having two or more (meth)acrylate groups, regardless of whether it has a cyclic skeleton, is classified as a (meth)acrylate having a hydroxyl group or a (meth)acrylate having a phosphate group if it has at least one hydroxyl group or phosphate group, and is classified as a compound having two or more (meth)acrylate groups if it does not have either a hydroxyl group or a phosphate group. In other words, (meth)acrylates having a cyclic skeleton include mono(meth)acrylates having a cyclic skeleton and having neither a hydroxyl group nor a phosphoric acid 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 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 the same type of monomer as the monofunctional (meth)acrylate having an aromatic ring described above in the polymerizable compound (a1). In this case, the content of the (meth)acrylate having a cyclic skeleton in the entire curable composition of the present invention may 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 (meth)acrylate having a cyclic skeleton blended as the polymerizable compound (a2).

[0038] The (meth)acrylate having a hydroxy 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 may be a compound made from a biomass raw material. In such a case, the curable composition of the present invention itself can be regarded as an environmentally friendly product, which is more preferable from the viewpoint of reducing the environmental load.

[0039] The curable composition of the present invention may further contain another polymerizable compound different from the above-mentioned polymerizable compound (a2). Examples of the other polymerizable compound include a monofunctional polymerizable compound, or a polymerizable compound having two or more polymerizable groups (hereinafter referred to as a "polyfunctional polymerizable compound") different from the above-mentioned compound having two or more (meth)acrylate groups. Here, the polymerizable group refers to a group having a polymerizable unsaturated double bond.

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

[0041] Examples of the monofunctional polymerizable compound that is another polymerizable compound include a polymerizable compound having a heterocyclic structure and a monovinyl ether compound. Examples of the polymerizable compound having a heterocyclic structure include N-vinylcaprolactam, N-vinylpyrrolidone, and N-vinylformamide.

[0042] Examples of the monovinyl ether compound 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] Examples of the polyfunctional polymerizable compound that is another polymerizable compound include a compound represented by the following general formula (1): ２ =CR ５ -COO-R ６ -O-CH=CH-R ７ ...(1) (wherein, R ５ represents a hydrogen atom or a methyl group, R ６ represents an organic residue having 2 to 20 carbon atoms, and R ７represents a hydrogen atom or an organic residue having 1 to 11 carbon atoms. ) (hereinafter simply referred to as "monomer (1)"), divinyl ether compounds, trivinyl ether compounds, etc. ６ Examples of the organic residue having 2 to 20 carbon atoms represented by R include a linear, branched or cyclic alkylene group having 2 to 20 carbon atoms, an alkylene group having 2 to 20 carbon atoms having an oxygen atom in its structure via an ether bond and / or an ester bond, and an aromatic group having 6 to 11 carbon atoms in which a hydrogen atom bonded to a carbon atom constituting the ring may be substituted with another substituent, and an alkylene group having 2 to 6 carbon atoms and an alkylene group having 2 to 9 carbon atoms having an oxygen atom in its structure via an ether bond are preferred. ７ Examples of the organic residue having 1 to 11 carbon atoms represented by the formula (I) include a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms, and an aromatic group having 6 to 11 carbon atoms in which a hydrogen atom bonded to a carbon atom constituting the ring may be substituted with another substituent, and an alkyl group having 1 or 2 carbon atoms and an aromatic group having 6 to 8 carbon atoms are preferred.

[0044] Specific examples of the monomer (1) include 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, and 3-methyl-3-vinyloxypropyl (meth)acrylate. vinyloxypropyl, 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, 2-(vinyloxy) Examples of the monomer (1) include 2-(vinyloxyethoxyisopropoxy)ethyl (meth)acrylate, 2-(vinyloxyethoxyisopropoxy)propyl (meth)acrylate, 2-(vinyloxyethoxyethoxy)isopropyl (meth)acrylate, 2-(vinyloxyethoxyisopropoxy)isopropyl (meth)acrylate, 2-(vinyloxyethoxyethoxyethoxy)ethyl (meth)acrylate, polyethylene glycol monovinyl ether (meth)acrylate, and polypropylene glycol monovinyl ether (meth)acrylate. From the viewpoints of low viscosity, high flash point, and excellent curability, 2-(2-vinyloxyethoxy)ethyl (meth)acrylate is preferred, and 2-(2-vinyloxyethoxy)ethyl acrylate is more preferred.

[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, and trimethylolpropane trivinyl ether.

[0046] When the curable composition of the present invention further contains another polymerizable compound, the other polymerizable compound may be used alone or in combination of two or more. When the other polymerizable compound is further contained, the content is preferably 30 mass % or less, more preferably 20 mass % or less, based on the total curable composition of the present invention, and from the viewpoint of easily adjusting the viscosity of the obtained curable composition of the present invention and the cure shrinkage rate of the cured product of the curable composition of the present invention, it is even more preferably 10 mass % or less.

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

[0048] Examples of the photopolymerization initiator (d) include 2-methylbenzoyldiphenylphosphine oxide, bis(2,6-dichlorobenzoyl)phenylphosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, 2,6-dimethoxybenzoyldiphenylphosphine oxide, 2,6-dichlorobenzoyldiphenylphosphine oxide, 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 methyl (2,4,6-trimethylbenzoyl)phenylphosphinate, ethyl (2,4,6-trimethylbenzoyl)phenylphosphinate, methyl (3-benzoyl-2,4,6-trimethylbenzoyl)phenylphosphinate, ethyl (3-benzoyl-2,4,6-trimethylbenzoyl)phenylphosphinate, and isopropyl pivaloylphenylphosphinate;Benzoin isobutyl ether, 2,4-diethylthioxanthone [also known as 2,4-diethylthioxanthen-9-one], 2-isopropylthioxanthone, methyl benzoyl formate, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 1-hydroxycyclohexyl phenyl ketone, benzoin ethyl ether, benzil dimethyl ketal, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methyl 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, and the like;

[0049] Among these, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, ethyl (2,4,6-trimethylbenzoyl)phenylphosphinate, and ethyl (3-benzoyl-2,4,6-trimethylbenzoyl)phenylphosphineate are preferred, as they correspond to the wavelength of light emitted from an ultraviolet light-emitting diode (UV-LED) light source as a light source of active energy rays. In particular, when a UV-LED having a main peak wavelength of 365 to 405 nm is used as the light source, it is preferred to use an acylphosphine compound, in particular 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) contains an oxime-based photopolymerization initiator. When the curable composition of the present invention contains an oxime-based photopolymerization initiator as the photopolymerization initiator (d), the obtained cured product tends to have excellent heat resistance and moisture resistance. Examples of oxime-based photopolymerization initiators include those described in J. C. S. Perkin II, 1979, pp. 1653-1660, J. C. S. Perkin II, 1979, pp. 156-162, and J. Photopolym. Sci. Tech., 1995 ...653-1660, J. C. S. Perkin II, 1979, pp. 1653-1660, J. C. S. Perkin II, 1979, pp. 1653-1660, and J. Photopolym. Sci. Tech., 1995, pp. 1653-1660, J. C. S. Perkin II, 1979, pp. 1653-1660 Examples of the oxime compound include compounds described in JP-A-202-232, JP-A-2000-66385, JP-A-2000-80068, JP-A-2001-233842, JP-T-2004-534797, JP-A-2006-342166, JP-A-2007-269779, JP-A-2009-191061, and JP-A-2012-032556. Among these, the oxime compound is preferably an oxime-based photopolymerization initiator having a maximum absorption wavelength in the wavelength region of 350 nm to 500 nm, and more preferably an oxime-based photopolymerization initiator having an absorption wavelength in the wavelength region of 360 nm to 480 nm. Commercially available oxime-based photopolymerization initiators can be used, and examples thereof include "Irgacure OXE01," "Irgacure OXE02," "Irgacure OXE03," and "Irgacure OXE04" manufactured by BASF Japan Ltd., and "TR-PBG-304" manufactured by Changzhou Strong Electronic New Materials Co., Ltd.

[0051] The photopolymerization initiator (d) may be contained alone or in combination of two or more. When the curable composition of the present invention contains the photopolymerization initiator (d), the content thereof is preferably 0.1 to 15 mass%, more preferably 0.5 to 12 mass%, and even more preferably 1.0 to 10 mass%, based on the total mass of the 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 become good, and the performance of the formed cured product tends to be improved.

[0052] When 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, the content thereof is preferably 0.1 to 10 mass%, and more preferably 0.5 to 8 mass%, relative to the total mass of the curable composition of the present invention. When the content of the sensitizer 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 be improved.

[0053] In addition to the above-described components, the curable composition of the present invention may further contain, if necessary, a polymerization inhibitor such as hydroquinone, di-t-butylhydroquinone, p-methoxyphenol, benzoquinone, dibutylhydroxytoluene, nitrosamine salts, hindered amine compounds, 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO), etc. When a polymerization inhibitor is contained, the amount thereof is preferably in the range of 0.01 to 2 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 constituent components of the dispersion of the present invention, a colorant (b) containing at least a bisbenzofuranone-based pigment, a dispersant (c), and preferably at least one polymerizable compound (a2) selected from a (meth)acrylate having a hydroxy group or a compound having two or more (meth)acrylate groups, more preferably a photopolymerization initiator (d), and the optional components described above. The content of the colorant (b) in the curable composition of the present invention can be controlled by the blending amount of the dispersion of the present invention used in preparing the curable composition of the present invention. The content of the colorant (b) is preferably in the range of 1 to 50% by mass, more preferably 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-based pigment in the colorant (b) is preferably 50 to 500 nm, more preferably 100 to 400 nm. When the content of the colorant (b) in the curable composition of the present invention is within the above range, the dispersibility of the colorant (b) is excellent, and the storage stability and curability of the curable composition of the present invention are excellent. In addition, the cured product of the curable composition of the present invention is excellent in heat resistance, light resistance, moisture resistance, and adhesion to a substrate, and is particularly likely to be excellent in low light transmittance (hiding performance).

[0055] The curable composition of the present invention may further contain a surfactant from the viewpoints of ensuring handleability and ejection stability applicable to ink-jet methods and adjusting the surface tension within a desired range. Specific examples of the surfactant are the same as those of the surfactant that may be contained in the dispersion of the present invention. When the curable composition of the present invention further contains a surfactant, the content thereof is preferably 0.05 to 1 mass %, and more preferably 0.1 to 0.8 mass %, based on the total mass of the curable composition of the present invention.

[0056] The curable composition of the present invention may further contain a leveling agent. The leveling agent easily smoothes the surface of the cured product formed from the curable composition, making it easier for the cured product to cure uniformly when irradiated with ultraviolet light, and therefore making it less likely for unevenness to occur in the cured product. Examples of leveling agents include silane compounds, fluorine compounds, acrylic copolymers, and alcohol alkoxylate compounds. The above-mentioned surfactants can also be used as leveling agents.

[0057] The curable composition of the present invention may further contain additives such as an ultraviolet absorber, an antioxidant, a surface tension modifier, a discoloration inhibitor, a conductive salt, etc. Furthermore, from the viewpoint of further improving adhesion to substrates such as plastic substrates, the curable composition may also contain a non-reactive resin such as an acrylic resin, an epoxy resin, a terpene phenol resin, or a rosin ester.

[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. It is preferable that the viscosity and surface tension of the curable composition of the present invention at 25°C be within the above-mentioned ranges from the viewpoints of improving the handleability of the curable composition of the present invention and improving the inkjet ejection stability when molding by an inkjet method. Here, the curable composition of the present invention may further contain a solvent for the purpose of adjusting the viscosity as described above, within a range that does not impair the effects of the present invention. However, it is preferable that the curable composition of the present invention is solvent-free. When the curable composition of the present invention is solvent-free, the drying step or heat treatment (annealing treatment) for removing the solvent can be omitted when curing the curable composition of the present invention, thereby simplifying the manufacturing process. Furthermore, the curable composition of the present invention has good curability, and outgassing from the solvent is less likely to occur from the cured product, which tends to improve safety. Therefore, it is easy to obtain a curable composition of the present invention that can be applied by an inkjet method and does not require annealing treatment.

[0059] The curable composition of the present invention can be produced by feeding the dispersion of the present invention, the polymerizable compound (a2) [a (meth)acrylate having a hydroxy group, a compound having two or more (meth)acrylate groups, a (meth)acrylate having a phosphate group, a (meth)acrylate having a cyclic skeleton], the photopolymerization initiator (d), and various optional components as needed, and stirring and mixing them using a conventional dispersing machine such as a bead mill or a stirrer. Here, as the dispersing machine, various known and commonly used dispersing machines such as a bead mill, an ultrasonic homogenizer, a high-pressure homogenizer, a paint shaker, a ball mill, a roll mill, a sand mill, a sand grinder, a Dyno Mill, a Dispermat, an SC Mill, and a Nanomizer can be used.

[0060] As described above, the curable composition of the present invention is preferably a curable composition that is cured by 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 is cured by irradiation with light such as ultraviolet light. Examples of light sources that can be used for ultraviolet light include metal halide lamps, xenon lamps, carbon arc lamps, chemical lamps, low-pressure mercury lamps, high-pressure mercury lamps, and UV-LED lamps. From the viewpoint of extremely low heat generation and environmental protection that can accommodate mercury-free trends, it is more preferable to cure the composition by light irradiation using a UV-LED lamp, preferably a UV-LED lamp with a main peak wavelength of approximately 365 to 405 nm that can provide sufficient illuminance. The irradiation energy of light using a UV-LED is 50 to 5,000 mJ / cm. ２ and preferably in the range of 200 to 3000 mJ / cm ２ The range is more preferable.

[0061] When the curable composition of the present invention is used as, for example, a black matrix for a light-emitting element, the method for forming the black matrix is ​​not particularly limited. Examples of the method include: applying the curable composition of the present invention between light-emitting elements by dropping, using a spin coater, a die coater, a dispenser, an inkjet method, a stencil printing method, a screen printing method, a gravure printing method, or through a mask to form a coating film preferably having the same thickness as the light-emitting elements, and then curing the film; injecting the curable composition of the present invention into a mold form using, for example, a dispenser, transfer molding, or injection molding, immersing a lead frame or the like to which a light-emitting element is fixed thereinto, and then curing the composition; injecting the curable composition of the present invention into a mold form into which a light-emitting element is inserted and then curing the composition; and injecting the curable composition of the present invention into a cup or the like having a light-emitting element disposed at the bottom thereof using a dispenser or the like, and then curing the composition. 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 light utilization efficiency.

[0062] Among these, molding by an inkjet method using an inkjet recording method is preferred. In this case, droplets of the curable composition of the present invention can be deposited on the target with high positional accuracy, thereby improving the accuracy of the shape and dimensions of the cured product. Furthermore, compared to molding by a printing method involving contact, such as screen printing, molding the curable composition of the present invention by an inkjet method is less likely to result in contamination of the curable composition of the present invention and its cured product, and less likely to result in a decrease in yield when producing a black matrix for a light-emitting element. In the inkjet method, any of the conventionally known ink ejection methods can be used, such as a method of ejecting droplets using the vibration of a piezoelectric element (a recording method using an inkjet head that forms ink droplets by mechanical deformation of an electrostrictive element), a method using thermal energy, a method using an actuator that uses electrostatic force, or a method using a continuous-jet charge-controlled head. Furthermore, the curable composition of the present invention can be molded by the inkjet method by previously heating it to reduce its viscosity before ejecting it from the inkjet head.

[0063] A cured product can be produced by ejecting the curable composition of the present invention, preferably by an inkjet method, molding the composition, and then curing it by irradiating it with active energy rays, preferably ultraviolet rays. The curable composition of the present invention is suitable as a material for forming a black layer on the upper part of the partition wall of a light-emitting element such as an organic EL element or an LED element, and as a composition for forming a black matrix of the light-emitting element. That is, one aspect of the present invention is an LED element including 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 a micro LED element. Another aspect of the present invention is an electronic device using a cured product of the curable composition of the present invention. Using a cured product of the curable composition of the present invention can improve the dimensional and shape accuracy of an electronic device, and can also exhibit the physical properties of the cured product of the curable composition of the present invention. Examples of such electronic devices include displays, projectors, mobile terminals, wristwatches, monitors, and other display devices, touch panels, or lighting devices that use 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 photoconductors (OPCs), organic transistors, and CMOS image sensors (CISs).

[0064] The use of the curable composition of the present invention is not limited to the electronic devices described above. The curable composition of the present invention can be applied to the production of various products utilizing its properties, such as a material for forming a black light-shielding area in the frame of an electronic device or a material for forming a filter capable of adjusting brightness, such as an ND filter.

[0065] Schematic examples of the configuration of a micro LED display, an electronic device using a cured product of the curable composition of the present invention, are shown in FIGS. 1 and 2 , but the present 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 No. 10,978,626 . In FIG. 1 , the micro LED display 100 includes a substrate 2, micro LED elements 1 mounted on the substrate 2, an encapsulant 3, joints 4 between the micro LED elements 1 and metal wiring (not shown) formed on the surface of the substrate 2, partition walls 5, and a black layer 6 covering the upper portions of the partition walls 5. The micro LED display 100 includes a plurality of micro LED elements 1, and the plurality of micro LED elements 1 are separated from adjacent micro LED elements 1 on the substrate 2 by partition walls 5. The black layer 6 is a cured product of the curable composition of the present invention. The substrate 2 can be, for example, a film made of a transparent inorganic material such as glass, or a heat-resistant resin material such as polyethylene naphthalate, polyamide, or polyimide. The thickness of the substrate 2 is not particularly limited, and in the case of a film, a thickness in the range of 25 to 125 μm is usually preferred from the viewpoint of a balance between heat resistance, insulation properties, manufacturing costs, etc. The thickness of the encapsulant 3 in the micro LED display 100 is usually preferably in the range of 5 to 100 μm, 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 also 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 of that surface or the opposing interface.

[0066] The micro LED display 100 shown in FIG. 1 can be manufactured, for example, as follows. First, a substrate 2 is prepared, and multiple micro LED elements 1 are mounted on one surface of the substrate 2. Next, a precursor for the partition walls 5 is formed to a predetermined height between the multiple micro LED elements 1 on one surface of the substrate 2 using, for example, a photosensitive material containing a white colorant, for example, by inkjet printing. The precursor is then cured by irradiating with ultraviolet light to form the partition walls 5. Next, the curable composition of the present invention is applied to the partition walls 5 by, for example, inkjet printing to form a coating film. The coating film of the curable composition of the present invention is then cured by irradiating with ultraviolet light to form the black layer 6. Next, a transparent encapsulant material is applied by, for example, inkjet printing to form a coating film covering the entire surfaces of the multiple micro LED elements 1, the partition walls 5, and the black layer 6. The coating film is then cured by irradiating with ultraviolet light to form the encapsulant 3. The ultraviolet light irradiation in the above manufacturing process may be performed in an oxygen-containing atmosphere, such as air, or in an inert atmosphere, such as a nitrogen atmosphere.

[0067] In FIG. 2 , the micro LED display 100 includes a substrate 2, multiple micro LED elements 1 mounted on the substrate 2, joints 4 between the micro LED elements 1 and metal wiring (not shown) formed on the surface of the substrate 2, and a black layer 6 covering the micro LED elements 1. The black layer 6 corresponds to a black matrix and is a cured product of the curable composition of the present invention. To manufacture the micro LED display 100 shown in FIG. 2 , for example, first prepare a substrate 2 and then mount multiple micro LED elements 1 on one surface of the substrate 2. Next, the curable composition of the present invention is applied between the multiple micro LED elements 1, for example, by an inkjet method, to form a coating film having the same thickness as the micro LED elements. The coating film of the curable composition of the present invention is then cured by irradiating it with ultraviolet light to form a black layer 6 covering the entire periphery of the multiple micro LED elements 1. This black layer 6 can enhance the contrast in electronic devices such as the micro LED display 100. UV irradiation of the coating film of the curable composition of the present invention may be performed in an oxygen-containing atmosphere, such as the air atmosphere, or in an inert atmosphere, such as a nitrogen atmosphere.

[0068] Although one embodiment of the dispersion, the curable composition, the cured product of the curable composition of the present invention and the method for producing the same, the LED element including the cured product, and the electronic device using the cured product of the present invention has been described above, the present invention is not limited to the configuration of the above-mentioned embodiment. For example, the curable composition of the present invention may have any other optional components in addition to the configuration of the above embodiment, or may be substituted with any optional components that produce the same effect.

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

[0070] <Polymerizable Compound a1> a1-1: Light Acrylate PO-A (trade name, manufactured by Kyoeisha Chemical Co., Ltd., phenoxyethyl acrylate (monofunctional (meth)acrylate), viscosity (25°C) 8 to 20 mPa·s) a1-2: Miramer M1182 (trade name, manufactured by MIWON Corporation, benzyl acrylate (monofunctional (meth)acrylate), viscosity (25°C) 1 to 10 mPa·s) a1-3: Viscoat 196 (trade name, manufactured by Osaka Organic Chemical Industry Ltd., 3,3,5-trimethylcyclohexyl acrylate ((meth)acrylate having an alicyclic skeleton), viscosity (25°C) 1 to 10 mPa·s) <Colorant (b)> b-1: lactone-based, Irgaphor Black S0100CF (manufactured by BASF Corporation), average particle size (D50) 250 nm b-2: Carbon black, MA11 (manufactured by Mitsubishi Chemical Corporation), average particle size (D50) 29 nm <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)acrylate Having an Aromatic Ring} a2-1: Light Acrylate PO-A (trade name, manufactured by Kyoeisha Chemical Co., Ltd., phenoxyethyl acrylate (monofunctional (meth)acrylate), viscosity (25°C) 8 to 20 mPa·s) {(Meth)acrylate Having a Hydroxy Group} a2-2: 4-HBA (trade name, manufactured by Osaka Organic Chemical Industry Ltd., 4-hydroxybutyl acrylate, viscosity (25°C) 5.5 mPa·s) a2-3: HPA (trade name, manufactured by Osaka Organic Chemical Industry Ltd., hydroxypropyl acrylate), viscosity (25°C) 4 mPa·s) {Compound Having Two or More (meth)acrylate Groups} a2-4: Miramer M320 (trade name, manufactured by MIWON Co., Ltd., glycerin propylene oxide adduct triacrylate, viscosity (25°C) 80 to 120 mPa·s) a2-5: Miramer M3130 (trade name, manufactured by MIWON Corporation; trimethylolpropane ethylene oxide-modified triacrylate; viscosity (25°C) 50 to 70 mPa·s) a2-6: ARONIX M-405 (trade name, manufactured by Toagosei Co., Ltd.; dipentaerythritol penta- and hexaacrylate; viscosity (25°C) 3700 to 5700 mPa·s) a2-7: Miramer M240 (trade name, manufactured by MIWON Corporation; ethylene oxide-modified bisphenol A diacrylate; viscosity (25°C) 900 to 1300 mPa·s) <Other polymerizable monomers> a2-8: EBECRYL 80 (manufactured by Daicel Allnex Corporation; amine-modified highly reactive polyether acrylate; viscosity (25°C) 3000 mPa·s) a2-9: EBECRYL7100 (manufactured by Daicel Allnex Corporation; aminoacrylate acrylate, viscosity (25°C) to 1200 mPa·s) a2-10: Viscoat 196 (trade name, manufactured by Osaka Organic Chemical Industry Ltd.; 3,3,5-trimethylcyclohexyl acrylate (a (meth)acrylate having an alicyclic skeleton), viscosity (25°C) to 10 mPa·s) a2-11: Isobornyl acrylate (manufactured by Osaka Organic Chemical Industry Ltd.; a (meth)acrylate having an alicyclic skeleton, viscosity (25°C) to 15 mPa·s)

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

[0073] <Polymerization inhibitor> Nonflex Alba: 2,5-di-t-butylhydroquinone (manufactured by Seiko Chemical Co., Ltd.) <Additive (leveling agent)> KF-54: polyether-modified polysiloxane (manufactured by Shin-Etsu Chemical Co., Ltd.) BYK-UV3500: acrylic group-containing polyether-modified polydimethylsiloxane (manufactured by BYK Corporation)

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

[0075] [Examples 1-5 to 1-7] Predetermined amounts of polymerizable compound (a1-2), colorant (b-1), and dispersant (c-1) were placed in a bead mill and stirred and mixed, and dispersibility was evaluated. The results are shown in Table 2. From the results of Examples 1-5 and 1-6, it can be determined that as long as the colorant concentration is up to about 50% by mass, the dispersibility and viscosity of the resulting dispersion are sufficient for practical use. On the other hand, in Example 1-7, the viscosity of the dispersion increased to an unmeasurable level, and the dispersibility of colorant (b-1) was also poor.

[0076]

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

[0078] [Examples 1-9 to 1-12] Polymerizable compound (a1-2) and polymerizable compound (a2-8) were mixed in a predetermined ratio, and predetermined amounts of colorant (b-1) and dispersant (c-1) were added to a bead mill and stirred. The dispersibility was evaluated. The results are shown in Table 3. From the results of Examples 1-4 and 1-9 to 1-10, it can be determined that when the polymerizable compound (a1-2) / polymerizable compound (a2-8) ratio was 1 / 0 to 1 / 6, the dispersibility was good and the viscosity was low, making it suitable for practical use. From the results of Example 1-11, when the polymerizable compound (a1-2) / polymerizable compound (a2-8) ratio was 1 / 9, the dispersibility was good, but the viscosity increased. Furthermore, from the results of Example 1-12, even when the polymerizable compound (a1-2) / polymerizable compound (a2-8) ratio was 1 / 6, the viscosity increased due to the increase in the concentration of colorant (b-1).

[0079]

[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 (a2-2), 5.0 parts by mass of (a2-4), and 4.1 parts by mass of (a2-8) as the polymerizable compound (a2), 1.5 parts by mass of (d-1), 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) as the photopolymerization initiator (d), 0.1 parts by mass of a polymerization inhibitor, and 0.1 parts by mass of a leveling agent were placed in a container and stirred and mixed to prepare curable composition 1. Table 4 shows the mass ratio of each component of curable composition 1 as a percentage. [Examples 2-2 to 2-13] 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 and mixed 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 Measurement was performed at a temperature of 25°C using an E-type viscometer (TVE-25L, manufactured by Toki Sangyo Co., Ltd.). The viscosity of each curable composition is shown in Table 1 using the following evaluation index. [Evaluation Index] A: 20 mPa s or less. B: More than 20 mPa s and 40 mPa s or less. C: More than 40 mPa s. Furthermore, when each curable composition was stored at -20 to 20°C, there was little change in viscosity, and all had good storage stability.

[0081] 3-2. Light transmittance of cured product (1) The curable composition obtained in each example was applied to a non-alkali glass substrate (35 mm length × 35 mm width, 0.7 mm thickness) using a spin coater to form a coating film with a thickness of approximately 5 μm. This coating film was then irradiated with UV-LED light at a peak wavelength of 365 nm and a peak irradiance of 1000 mW / cm using a UV-LED irradiation device (manufactured by ITEC Systems Co., Ltd.). ２ , cumulative light intensity 3 J / cm ２ The coating was cured by irradiating ultraviolet light under the conditions of (a) to (b) to produce a cured product (cured coating film). (2) The light transmittance of each of the cured products obtained above in the wavelength range of 400 to 800 nm was measured using a spectrometer ("LCD-5200" manufactured by Otsuka Electronics Co., Ltd.). The measured light transmittance of only the alkali-free glass substrate used in producing the cured product was used as the reference value. Each of the cured products was almost black. The light transmittance value of each of the cured products at 550 nm is shown in Table 1.

[0082] 3-3. Adhesion of Cured Products In the same manner as in 3-2(1), cured products (cured coating films) of the curable compositions obtained in each Production Example were prepared, and a cross-shaped notch was made on the surface of the cured product using a cutter. Next, adhesive tape (manufactured by Nichiban Co., Ltd.) was applied to the cross-shaped notch and then peeled off. Furthermore, the procedure of applying new adhesive tape to the same cross-shaped notch as above and peeling it off was repeated a total of five times. After each operation, the cured coating film was visually observed for peeling from the alkali-free glass substrate after peeling off the adhesive tape, and the adhesion was evaluated as follows: [Evaluation Criteria] A: No peeling of the cured coating film occurred. B: Peeling of the cured coating film occurred after the third or subsequent application. C: Peeling of the cured coating film was observed after the first or second application.

[0083] 3-4. Heat resistance of cured product In the same manner as in 3-2(1), a cured product (cured coating film) was prepared from the curable composition obtained in each production example. Each cured product was placed in a clean oven (manufactured by ESPEC Corporation) at 120°C and aged for 500 hours, 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 difference ΔE between the value calculated from the initial light transmittance (measured in 3-2) and the value after 500 hours of aging (color difference generally used in CIE LAB color difference determination; ΔE ＊ ab = {(ΔL ＊ ) ２ + (Δa ＊ ) ２ + (Δb ＊ ) ２} １／２ ] was calculated, and the heat resistance was evaluated according to the following evaluation criteria: [Evaluation criteria] A: 0≦ΔE<0.1 B: 0.1≦ΔE<0.3 C: 0.3≦ΔE

[0084] 3-5. Light resistance of cured product In the same manner as in 3-2(1), a cured product (cured coating film) of the curable composition obtained in each production example was prepared and tested using a Suntest device (ATLAS Material Testing Technology GmbH, CPS+, 765 W / m ２ Each cured product was placed in a room (room temperature: 50°C, room temperature: 125°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, and the light resistance was evaluated using the following evaluation criteria. 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 Cured products (cured coating films) of the curable compositions obtained in each Production Example were prepared in the same manner as in 3-2(1), and each cured product was placed in a thermostatic chamber at 85°C and a relative humidity of 85% for 500 hours. The cured products were removed and allowed to cool naturally to 25°C, after which the presence or absence of surface non-uniformity was observed under a microscope (100x magnification), and the moisture resistance was evaluated according to the following criteria. [Evaluation Criteria] A: No change B: Non-uniformity on the surface of the cured product was observed under a microscope at 100x magnification C: Non-uniformity on the surface of the cured product was visible without the need for microscopic observation

[0086] The mass ratio of each component contained in each curable composition and the above-mentioned evaluation results are summarized in Tables 4 and 5. Tables 4 and 5 also show the ratio of the compound having two or more (meth)acrylate groups to the total mass of the curable composition (polyfunctional compound ratio; mass %) and the ratio of the photopolymerization initiator (d) to the total mass of the curable composition (photopolymerization initiator (d) ratio; mass %) in each curable composition of each example.

[0087]

[0088]

[0089] These results demonstrate that a curable composition containing a dispersion containing a polymerizable compound (a1), a bisbenzofuranone pigment as a colorant (b), and a dispersant (c), a (meth)acrylate having a hydroxy group and a compound having two or more (meth)acrylate groups as a polymerizable compound (a2), and preferably a predetermined amount or more of a photopolymerization initiator, has low viscosity, is easy to handle, and has excellent storage stability. Furthermore, the cured product exhibits excellent curability, adhesion to a substrate, heat resistance, light resistance, and moisture resistance. In particular, the light transmittance of the cured product at a film thickness of approximately 5 μm is within the range of 0.1 to 1.0%, demonstrating excellent low light transmittance (hiding performance). Furthermore, the transmitted light of a cured film formed from the cured product of the curable composition of the present invention has a color tone close to neutral, making the composition suitable as a black matrix material. On the other hand, in the curable composition (Example 2-3) composed of a dispersion in which the black component is carbon black, the UV transmittance of carbon black is lower than that of the bisbenzofuranone pigment, and compared to the curable composition of the present invention, the curability tends to be insufficient with UV irradiation alone, and the cured product is inferior in adhesion and moisture resistance. Furthermore, the transmitted light of the cured film composed of the cured product of the curable composition of Example 2-3 is slightly yellowish to reddish.

[0090] The curable composition of the present invention has excellent curability and can be used to form a molded product by an inkjet method. The resulting cured product has excellent heat resistance, light resistance, moisture resistance, and low light transmittance (shielding performance). The curable composition of the present invention is particularly suitable as a composition for forming a black matrix of a light-emitting element, and is useful as a light-shielding (shielding performance) material for a micro LED element. Furthermore, electronic devices using a cured product 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 photoconductors (OPCs), organic transistors, CMOS image sensors (CISs), etc.

[0091] REFERENCE SIGNS LIST 1 Micro LED element 2 Substrate 3 Encapsulant 4 Joint 5 Partition 6 Black layer 100 Micro LED display

Claims

1. 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) relative to the entire dispersion is in the range of 1 to 50 mass%, and the dispersion does not contain a solvent.

2. The dispersion according to claim 1, wherein the viscosity of the polymerizable compound (a1) at 25° C. is 30 mPa·s or less.

3. The dispersion according to claim 1, wherein the polymerizable compound (a1) contains a monofunctional (meth)acrylate.

4. The dispersion according to claim 3, wherein the monofunctional (meth)acrylate is a monofunctional (meth)acrylate having an aromatic ring.

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

6. A curable composition comprising the dispersion according to claim 1 and a polymerizable compound (a2).

7. The curable composition according to claim 6, wherein the polymerizable compound (a2) contains a (meth)acrylate having a hydroxy group.

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

9. The curable composition according to claim 6, further comprising a photopolymerization initiator (d).

10. The curable composition according to claim 9, wherein the photoinitiator (d) comprises an oxime-based photoinitiator.

11. The curable composition according to claim 6, wherein the content of the colorant (b) is 1 to 50% by mass based on the total mass of the curable composition.

12. The curable composition according to claim 6, wherein the average particle size (D50) of the bisbenzofuranone pigment in the colorant (b) is 50 to 500 nm.

13. The curable composition according to claim 6, which is an active energy ray curable composition.

14. The curable composition according to claim 6, having a viscosity at 25° C. of 3 to 30 mPa·s.

15. The curable composition of claim 6, which is solvent-free.

16. A cured product of the curable composition according to any one of claims 6 to 15.

17. A method for producing a cured product, comprising a step of curing the curable composition according to any one of claims 6 to 15 by irradiating it with active energy rays.

18. The method according to claim 17, wherein the curable composition is formed by an ink-jet method.

19. An electronic device using a cured product of the curable composition according to any one of claims 6 to 15.

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