JP7638878B2 - Photocurable black composition, cured product of photocurable black composition, and black coated substrate - Google Patents

Description

The present invention relates to a photocurable black composition, a cured product of the photocurable black composition, and a black-coated substrate having a cured coating of the photocurable black composition, and in particular to a photocurable black composition that allows alkaline development, a cured product of the photocurable black composition, and a black-coated substrate in which a transparent substrate is coated with a cured coating of the photocurable black composition.

In recent years, there has been a need to display analog in-vehicle instruments such as speedometers on a vehicle's instrument panel instead of placing them on the panel. In this case, the periphery of the display area on the display is covered with a coating made of black resist, and a black matrix is formed in the display area.

A colored photosensitive resin composition used to form a black matrix is disclosed, for example, in Patent Document 1. Specifically, Patent Document 1 discloses a colored photosensitive composition that contains a photopolymerizable compound, a photopolymerization initiator, and a colorant as a light-blocking agent in order to ensure light-blocking properties. This colored photosensitive composition forms a black matrix with high light-blocking properties, and by applying it to a color filter, it is possible to improve the contrast of a liquid crystal display and prevent light leakage.

JP 2009-168948 A

However, the inventors have found through their studies that when light hits a display having a coating or black matrix formed from a black resist based on a composition using a conventional colorant such as carbon black or titanium black as shown in Patent Document 1 from the glass side, i.e., from the user's side looking at the display, the light is dimly reflected not only in the area where the light hits but also in the surrounding area, causing the area where the light hits and the surrounding area to look dimly white (hereinafter, this phenomenon is also referred to as white blur in this specification). In particular, white blur becomes noticeable when a relatively large coating area formed from black resist is illuminated by an interior light or the like inside a vehicle or the like. White blur leads to a deterioration in visibility of the display area and its surroundings.

The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a photocurable black composition for forming a black shielding material that reduces the reflection of light irradiated from the user to the display.

The present inventors conducted extensive research to achieve the above object. As a result, they discovered that the above object can be achieved by using carbon black having a specific nitrogen adsorption surface area as a light-blocking colorant, and thus completed the present invention.

That is, the above object of the present invention is to
(A) an alkali-soluble resin;
(B) a photopolymerization initiator;
(C) a photopolymerizable multifunctional monomer;
(D) carbon black having a nitrogen adsorption specific surface area based on JIS K6217-2:2017 of 300 m ² /g or more;
It has been found that this can be achieved by a photocurable black composition comprising:

It is preferable that the photocurable black composition of the present invention further contains (E) an ester of cellulose and a short-chain fatty acid.

Furthermore, it is preferable that the (C) photopolymerizable multifunctional monomer contains (C1) an RO-addition photopolymerizable multifunctional monomer and (C2) a lactone-addition photopolymerizable multifunctional monomer, and it is even more preferable that the mass ratio (solid content) of (C1) RO-addition photopolymerizable multifunctional monomer/(C2) lactone-addition photopolymerizable multifunctional monomer is in the range of 0.5 or more and 10 or less.

In addition, it is preferable that the (D) carbon black has a nitrogen adsorption specific surface area based on JIS K6217-2:2017 of 300 m ² /g or more and 400 m ² /g or less.

It is also preferable that it contains (F) a thermosetting component.

Furthermore, the above-mentioned object of the present invention can also be achieved by a black-coated substrate characterized by having a cured product of the photocurable black composition of the present invention, a transparent substrate, and a cured coating of the photocurable black composition of the present invention.

According to the present invention, a cured coating formed from a photocurable black composition is applied onto a transparent substrate, and when light is irradiated onto the cured coating through the transparent substrate, reflection of light is suppressed, thereby suppressing the occurrence of white blur on the cured coating, and improving visibility when applied to organic or inorganic EL displays, liquid crystal displays, etc.

<Photocurable black composition>
The photocurable black composition of the present invention comprises:
(A) an alkali-soluble resin;
(B) a photopolymerization initiator;
(C) a photopolymerizable multifunctional monomer;
and (D) carbon black having a nitrogen adsorption specific surface area based on JIS K6217-2:2017 of 300 m ² /g or more.

[(A) Alkali-soluble resin]
The alkali-soluble resin (A) is a resin that enables the photocurable black composition to be dissolved in an alkali developer, i.e., enables development with an alkali.

(A) The alkali-soluble resin may or may not have an ethylenically unsaturated group. The ethylenically unsaturated group is a substituent having an ethylenically unsaturated bond, such as a vinyl group or a (meth)acryloyl group. From the viewpoint of reactivity, the (meth)acryloyl group is preferable. Here, the (meth)acryloyl group is a general term for an acryloyl group and a methacryloyl group.

(A) As the alkali-soluble resin, it is preferable to use a carboxyl group-containing resin or a phenol resin. In particular, it is more preferable to use a carboxyl group-containing resin from the standpoint of developability.

As the carboxyl group-containing resin, various conventionally known carboxyl group-containing resins that have a carboxyl group in the molecule and further do not have an ethylenically unsaturated group (non-photosensitive) or that do have an ethylenically unsaturated group (photosensitive) can be used.

Specific examples of carboxyl group-containing resins that do not have ethylenically unsaturated groups include the following compounds (which may be either oligomers or polymers):

(1) Carboxyl group-containing urethane resins obtained by polyaddition reaction of diisocyanates such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates with diol compounds containing carboxyl groups such as dimethylolpropionic acid and dimethylolbutanoic acid, such as dialcohol compounds, polycarbonate polyols, polyether polyols, polyester polyols, polyolefin polyols, bisphenol A alkylene oxide adduct diols, and compounds having phenolic hydroxyl groups and alcoholic hydroxyl groups.

(2) A carboxyl group-containing urethane resin obtained by a polyaddition reaction between a diisocyanate and a carboxyl group-containing dialcohol compound.

(3) Carboxyl group-containing resins obtained by copolymerization of unsaturated carboxylic acids such as (meth)acrylic acid with unsaturated group-containing compounds such as styrene, α-methylstyrene, lower alkyl (meth)acrylates, and isobutylene.

(4) Carboxyl group-containing polyester resins obtained by reacting a dicarboxylic acid such as adipic acid, phthalic acid, or hexahydrophthalic acid with a bifunctional epoxy resin or a bifunctional oxetane resin, and then adding a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, or hexahydrophthalic anhydride to the resulting hydroxyl groups.

(5) A carboxyl group-containing resin obtained by ring-opening an epoxy resin or an oxetane resin and reacting the resulting hydroxyl group with a polybasic acid anhydride.

(6) A carboxyl group-containing resin obtained by reacting a reaction product such as a polyalcohol resin obtained by reacting a compound having multiple phenolic hydroxyl groups in one molecule, i.e., a polyphenol compound, with an alkylene oxide such as ethylene oxide or propylene oxide, with a polybasic acid anhydride.

Specific examples of carboxyl group-containing resins having ethylenically unsaturated groups include the following compounds (which may be either oligomers or polymers). The ethylenically unsaturated bond in the carboxyl group-containing resin is preferably derived from acrylic acid or methacrylic acid or a derivative thereof.

(7) Carboxyl group-containing photosensitive urethane resins obtained by the polyaddition reaction of diisocyanates, such as aliphatic diisocyanates, branched aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates, with diol compounds, such as dialcohol compounds containing carboxyl groups, such as dimethylolpropionic acid and dimethylolbutanoic acid, polycarbonate-based polyols, polyether-based polyols, polyester-based polyols, polyolefin-based polyols, acrylic polyols, bisphenol A-based alkylene oxide adduct diols, and compounds having phenolic hydroxyl groups and alcoholic hydroxyl groups.

(8) A carboxyl group-containing photosensitive urethane resin obtained by a polyaddition reaction of a diisocyanate with a (meth)acrylate or a partially acid anhydride-modified product of a bifunctional epoxy resin such as bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bixylenol type epoxy resin, or biphenol type epoxy resin, and a carboxyl group-containing dialcohol compound.

(9) A carboxyl group-containing photosensitive urethane resin that has been terminally (meth)acrylated by adding a compound having one hydroxyl group and one or more (meth)acryloyl groups in the molecule, such as a hydroxyalkyl (meth)acrylate, during the synthesis of the resin (7) or (8) described above.

(10) A carboxyl group-containing photosensitive urethane resin that has been (meth)acrylated at the terminal by adding a compound having one isocyanate group and one or more (meth)acryloyl groups in the molecule, such as an equimolar reactant of isophorone diisocyanate and pentaerythritol triacrylate, during the synthesis of the resin (8) or (9) described above.

(11) A carboxyl group-containing photosensitive resin obtained by reacting a difunctional or more polyfunctional (solid) epoxy resin with (meth)acrylic acid and adding a dibasic acid anhydride to the hydroxyl groups present in the side chains.

(12) A carboxyl group-containing photosensitive resin obtained by reacting a polyfunctional epoxy resin in which the hydroxyl groups of a bifunctional (solid) epoxy resin have been further epoxidized with epichlorohydrin with (meth)acrylic acid, and then adding a dibasic acid anhydride to the resulting hydroxyl groups.

(13) A carboxyl group-containing polyester photosensitive resin obtained by reacting a dicarboxylic acid such as adipic acid, phthalic acid, or hexahydrophthalic acid with a bifunctional oxetane resin, and then adding a dibasic acid anhydride such as phthalic anhydride, tetrahydrophthalic anhydride, or hexahydrophthalic anhydride to the resulting primary hydroxyl groups.

(14) A carboxyl group-containing photosensitive resin obtained by reacting a compound having multiple phenolic hydroxyl groups in one molecule, i.e., a polyphenol compound, with an alkylene oxide such as ethylene oxide or propylene oxide to obtain a reaction product such as a polyalcohol resin, reacting the reaction product with an unsaturated group-containing monocarboxylic acid such as (meth)acrylic acid, and further reacting the resulting reaction product with a polybasic acid anhydride.

(15) A carboxyl group-containing photosensitive resin obtained by reacting a compound having multiple phenolic hydroxyl groups in one molecule with a cyclic carbonate compound such as ethylene carbonate or propylene carbonate, reacting the reaction product obtained with an unsaturated group-containing monocarboxylic acid, and reacting the resulting reaction product with a polybasic acid anhydride.

(16) A carboxyl group-containing photosensitive resin obtained by further adding a compound having one epoxy group and one or more (meth)acryloyl groups in one molecule to the carboxyl group-containing resin (3) described above.

These photosensitive carboxyl group-containing resins may also be used other than those described as (7) to (16), and may be used alone or in combination. In particular, it is preferable to use the carboxyl group-containing photosensitive resin described in (16).

In (16), the unsaturated carboxylic acid is a compound having one unsaturated group and at least one carboxyl group in one molecule, and examples thereof include acrylic acid, methacrylic acid, modified unsaturated monocarboxylic acids in which the unsaturated group and the carboxylic acid are chain-extended, such as β-carboxyethyl (meth)acrylate, 2-acryloyloxyethyl succinic acid, 2-acryloyloxyethyl hexahydrophthalic acid, unsaturated monocarboxylic acids having an ester bond due to lactone modification, modified unsaturated monocarboxylic acids having an ether bond, and even those containing two or more carboxyl groups in the molecule, such as maleic acid. These may be used alone or in a mixture of two or more.

In addition, in (16), the unsaturated group-containing compound is preferably a (meth)acrylic acid ester, for example, (meth)acrylic acid alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, and hexyl (meth)acrylate; hydroxyl group-containing (meth)acrylic acid esters such as 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and caprolactone-modified 2-hydroxyethyl (meth)acrylate; and glycol-modified (meth)acrylates such as methoxydiethylene glycol (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, isooctyloxydiethylene glycol (meth)acrylate, phenoxytriethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, and methoxypolyethylene glycol (meth)acrylate. These may be used alone or in combination of two or more. In this specification, (meth)acrylate is a general term for acrylate and methacrylate.

Furthermore, in (16), the compound having one epoxy group and one or more (meth)acryloyl groups in one molecule may be a compound having an ethylenically unsaturated group and an oxirane ring in one molecule, such as glycidyl (meth)acrylate, α-methylglycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, 3,4-epoxycyclohexylethyl (meth)acrylate, 3,4-epoxycyclohexylbutyl (meth)acrylate, and 3,4-epoxycyclohexylmethylaminoacrylate. Of these, 3,4-epoxycyclohexylmethyl (meth)acrylate is preferred. These (b) compounds having an oxirane ring and an ethylenically unsaturated group in one molecule may be used alone or in a mixture of two or more.

The following can be said about the above-mentioned carboxyl group-containing resins, regardless of whether they are photosensitive or non-photosensitive: Since the backbone polymer has many carboxyl groups on its side chains, development with a dilute alkaline aqueous solution is possible.

The acid value of the carboxyl group-containing resin is preferably in the range of 20 to 200 mgKOH/g, more preferably in the range of 40 to 150 mgKOH/g. When the acid value of the carboxyl group-containing resin is 20 mgKOH/g or more, the adhesion of the coating film is good and alkaline development is good. On the other hand, when the acid value is 200 mgKOH/g or less, dissolution of the exposed area by the developer can be suppressed, so that the lines are prevented from becoming thinner than necessary, and in some cases, the exposed and unexposed areas are prevented from being dissolved and peeled off by the developer without distinction, allowing a good resist pattern to be drawn.

The weight-average molecular weight of the above-mentioned carboxyl group-containing resin varies depending on the resin skeleton, but is generally preferably in the range of 2,000 to 150,000, and more preferably 5,000 to 100,000. When the weight-average molecular weight is 2,000 or more, the tack-free performance is good, the development resistance of the coating film after exposure is good, film loss during development is suppressed, and the resolution is also good. On the other hand, when the weight-average molecular weight is 150,000 or less, the developability is good and the storage stability is also excellent.

The amount of such carboxyl group-containing resin is suitably in the range of 10 to 95% by mass, preferably 10 to 80% by mass, based on the total mass (solid content) of the photocurable black composition. When the amount of carboxyl group-containing resin is in the range of 10% to 95% by mass based on the total mass (solid content) of the photocurable black composition, the coating strength is good, and the viscosity of the photocurable black composition is appropriate, improving the coatability, etc.

In addition, in the present invention, as the alkali-soluble resin (A), it is possible to use either a photosensitive carboxyl group-containing resin or a carboxyl group-containing resin that does not have photosensitivity, or to use a mixture of these.

The mixing ratio may be any ratio as long as it is adjusted so that the ethylenically unsaturated bond equivalent of the alkali-soluble resin (A) is 1,200 or more.

The photosensitive carboxyl group-containing resin and the non-photosensitive carboxyl group-containing resin may be other than those described above, and each may be used alone or in combination. Among the carboxyl group-containing resins, resins without aromatic rings are particularly preferred because they have excellent light resistance.

The phenolic resin may be a compound having a phenolic hydroxyl group, such as a compound having a biphenyl skeleton or a phenylene skeleton or both, or a phenolic hydroxyl group-containing compound, such as phenol, orthocresol, paracresol, metacresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, catechol, resorcinol, hydroquinone, methylhydroquinone, 2,6-dimethylhydroquinone, trimethylhydroquinone, pyrogallol, phloroglucinol, or the like.

For example, well-known and commonly used phenolic resins such as phenol novolac resin, alkylphenol volac resin, bisphenol A novolac resin, dicyclopentadiene type phenolic resin, Xylok type phenolic resin, terpene modified phenolic resin, polyvinylphenols, bisphenol F, bisphenol S type phenolic resin, poly-p-hydroxystyrene, condensation products of naphthol and aldehydes, and condensation products of dihydroxynaphthalene and aldehydes can be used.

These can be used alone or in combination of two or more.

Examples of commercially available phenolic resins include HF1H60 (manufactured by Meiwa Kasei Co., Ltd.), Phenolite TD-2090, Phenolite TD-2131 (manufactured by Dai Nippon Printing Co., Ltd.), Besumor CZ-256-A (manufactured by DIC Corporation), Showol BRG-555, Showol BRG-556 (manufactured by Showa Denko KK), CGR-951 (manufactured by Maruzen Oil Co., Ltd.), and polyvinylphenols CST70, CST90, S-1P, and S-2P (manufactured by Maruzen Oil Co., Ltd.). These phenolic resins can be used alone or in appropriate combination of two or more types.

In the present invention, as the alkali-soluble resin (A), either a carboxyl group-containing resin or a phenolic resin, or a mixture of these, may be used as long as it satisfies the conditions that it has an ethylenically unsaturated bond equivalent of 1,200 or more or does not have an ethylenically unsaturated group.

In addition, the photocurable black composition used in the present invention further contains the following photopolymerization initiator.

[(B) Photopolymerization initiator]
The photopolymerization initiator (B) polymerizes the (meth)acrylate by irradiation with energy rays. Examples of the photopolymerization initiator (B) include known and commonly used compounds such as benzophenone-based, acetophenone-based, aminoacetophenone-based, benzoin ether-based, benzil ketal-based, acylphosphine oxide-based, oxime ether-based, oxime ester-based, and titanocene-based compounds.

As the (B) photopolymerization initiator, an oxime ester-based photopolymerization initiator containing a structural portion represented by the following general formula (I) is preferred. The oxime ester-based photopolymerization initiator is more preferably a dimeric oxime ester-based photopolymerization initiator. The oxime ester-based photopolymerization initiator preferably has a carbazole structure, and more preferably is a dimeric oxime ester-based photopolymerization initiator having a carbazole structure. As the aminoacetophenone-based photopolymerization initiator, an α-aminoacetophenone-based photopolymerization initiator containing a structural portion represented by the following general formula (II) is given. As the acylphosphine oxide-based photopolymerization initiator, an acylphosphine oxide-based photopolymerization initiator containing a structural portion represented by the following general formula (III) is given. As the titanocene-based photopolymerization initiator, a titanocene-based photopolymerization initiator represented by the general formula (IV) is given.

In formula (I), ^R1 represents a hydrogen atom, a phenyl group, an alkyl group, a cycloalkyl group, an alkanoyl group, or a benzoyl group, and ^R2 represents a phenyl group, an alkyl group, a cycloalkyl group, an alkanoyl group, or a benzoyl group.

The phenyl group represented by R ¹ and R ² may have a substituent, and examples of the substituent include an alkyl group having 1 to 6 carbon atoms, a phenyl group, a halogen atom, and the like.

The alkyl group represented by ^R1 and ^R2 is preferably an alkyl group having 1 to 20 carbon atoms, which may contain one or more oxygen atoms in the alkyl chain, and may be substituted with one or more hydroxyl groups.

The cycloalkyl group represented by R ¹ and R ² is preferably a cycloalkyl group having 5 to 8 carbon atoms.

The alkanoyl group represented by R ¹ and R ² is preferably an alkanoyl group having 2 to 20 carbon atoms.

The benzoyl group represented by R ¹ and R ² may have a substituent, and examples of the substituent include an alkyl group having 1 to 6 carbon atoms, a phenyl group, and the like.

In general formula (II), ^R3 and ^R4 each independently represent an alkyl group or an arylalkyl group having 1 to 12 carbon atoms, and ^R5 and ^R6 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, or two of them may be bonded to form a cyclic alkyl ether group.

In general formula (III), R ⁷ and R ⁸ each independently represent an alkyl group having 1 to 10 carbon atoms, a cyclohexyl group, a cyclopentyl group, an aryl group, or an aryl group substituted with a halogen atom, an alkyl group, or an alkoxy group, or a carbonyl group having 1 to 20 carbon atoms (excluding the case where both are carbonyl groups having 1 to 20 carbon atoms).

In formula (IV), R ⁹ and R ¹⁰ each independently represent a halogen atom, an aryl group, a halogenated aryl group, or a heterocycle-containing halogenated aryl group.

Examples of oxime ester photopolymerization initiators containing the structural portion represented by general formula (I) include 1,2-octanedione-1-[4-(phenylthio)-2-(O-benzoyloxime)], the compound represented by the following formula (I-1), 2-(acetyloxyiminomethyl)thioxanthen-9-one, and oxime ester compounds having a carbazole skeleton, such as ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime), and the compound represented by the following general formula (I-2).

In the general formula (I-2), R ¹¹ has the same meaning as R ¹ in the general formula (I), and R ¹² and R ¹⁴ each independently have the same meaning as R ² in the general formula (I). R ¹³ represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyclopentyl group, a cyclohexyl group, a phenyl group, a benzyl group, a benzoyl group, an alkanoyl group having 2 to 12 carbon atoms, an alkoxycarbonyl group having 2 to 12 carbon atoms (when the carbon number of the alkyl group constituting the alkoxyl group is 2 or more, the alkyl group may be substituted with one or more hydroxyl groups and may have one or more oxygen atoms in the middle of the alkyl chain), or a phenoxycarbonyl group.

Such oxime ester photopolymerization initiators are preferred because, for example, they can increase the sensitivity of the photocurable black composition of the present invention to exposure to light for direct imaging, and provide excellent resolution. It is particularly preferred that the oxime ester photopolymerization initiator is a dimer.

As a dimeric oxime ester-based photopolymerization initiator, a compound represented by the following general formula (I-3) is more preferred.

In formula (I-3), R ²³ represents a hydrogen atom, an alkyl group, an alkoxy group, a phenyl group, or a naphthyl group. R ²¹ and R ²² each independently represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen group, a phenyl group, a naphthyl group, an anthryl group, a pyridyl group, a benzofuryl group, or a benzothienyl group.

Ar represents a single bond, an alkylene group having 1 to 10 carbon atoms, a vinylene group, a phenylene group, a biphenylene group, a pyridylene group, a naphthylene group, an anthrylene group, a thienylene group, a furylene group, a 2,5-pyrrole-diyl group, a 4,4'-stilbene-diyl group, or a 4,2'-styrene-diyl group.

n represents an integer between 0 and 1.

The alkyl group represented by R ²³ is preferably an alkyl group having 1 to 17 carbon atoms.

The alkoxy group represented by R ²³ is preferably an alkoxy group having 1 to 8 carbon atoms.

The phenyl group represented by R ²³ may have a substituent. Examples of the substituent include an alkyl group (preferably having 1 to 17 carbon atoms), an alkoxy group (preferably having 1 to 8 carbon atoms), an amino group, an alkylamino group (preferably having an alkyl group with 1 to 8 carbon atoms), and a dialkylamino group (preferably having an alkyl group with 1 to 8 carbon atoms).

The naphthyl group represented by R ²³ may have a substituent, and examples of the substituent include the same groups as the above-mentioned substituents which the phenyl group represented by R ²³ may have.

The alkyl group represented by R ²¹ and R ²² is preferably an alkyl group having 1 to 17 carbon atoms.

The alkoxy group represented by R ²¹ and R ²² is preferably an alkoxy group having 1 to 8 carbon atoms.

The phenyl group represented by R ²¹ and R ²² may have a substituent. Examples of the substituent include an alkyl group (preferably having 1 to 17 carbon atoms), an alkoxy group (preferably having 1 to 8 carbon atoms), an amino group, an alkylamino group (preferably having an alkyl group with 1 to 8 carbon atoms), and a dialkylamino group (preferably having an alkyl group with 1 to 8 carbon atoms).

The naphthyl group represented by R ²¹ and R ²² may have a substituent, and examples of the substituent include the same groups as the above-mentioned substituents which the phenyl group represented by R ²¹ and R ²² may have.

Furthermore, in general formula (I-3), it is preferable that R ²¹ and R ²³ are each independently a methyl group or an ethyl group, R ²² is methyl or phenyl, Ar is a single bond, a phenylene group, a naphthylene group or a thienylene group, and n is 0.

As the compound represented by general formula (I-3), the following compound is more preferred.

When such an oxime ester-based photopolymerization initiator is used, it is preferable to use it in combination with an acylphosphine oxide-based photopolymerization initiator containing a structural portion represented by general formula (III), since this improves the sensitivity to light exposure and results in a good cross-sectional shape of the cured coating of the photocurable black composition.

Examples of α-aminoacetophenone-based photopolymerization initiators containing the structural portion represented by general formula (II) include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropanone-1, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, and N,N-dimethylaminoacetophenone. Commercially available products include Omnirad 907, Omnirad 369, and Omnirad 379 manufactured by IGM Resins B.V.

Examples of acylphosphine oxide photopolymerization initiators containing the structural portion represented by general formula (III) include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide. Commercially available products include Omnirad TPO and Omnirad 819 manufactured by IGM Resins B.V.

Examples of titanocene photopolymerization initiators represented by general formula (IV) include bis(η5-2,4-cyclopentadiene-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium.

Commercially available oxime ester photopolymerization initiators include IRGACURE OXE01 (1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)]) and IRGACURE OXE02 (ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(0-acetyloxime)) manufactured by BASF Japan, N-1919 and NCI-831 manufactured by ADEKA, TR-PBG-304 manufactured by Changzhou Power Electronics New Materials Co., Ltd., and TOE-04-A3 manufactured by Nippon Chemical Industry Co., Ltd.

(B) The photopolymerization initiator is present in an amount of 1 part by mass or more and 30 parts by mass or less per 100 parts by mass (solids) of (A) the alkali-soluble resin, preferably 3 parts by mass or more and 25 parts by mass or less, and more preferably 4 parts by mass or more and 20 parts by mass or less.

(B) The amount of photopolymerization initiator blended is 1 part by mass or more and 30 parts by mass or less per 100 parts by mass (solids) of (A) alkali-soluble resin, thereby achieving good resolution.

[(C) Photopolymerizable polyfunctional monomer]
The photocurable black composition of the present invention contains a known and commonly used photopolymerizable polyfunctional monomer. The photopolymerizable polyfunctional monomer is a compound having two or more ethylenically unsaturated groups in one molecule. The photopolymerizable polyfunctional monomer is photocured by irradiation with active energy rays, thereby curing the photocurable black composition.

Examples of compounds used as the photopolymerizable polyfunctional monomer include commonly known polyester (meth)acrylates, polyether (meth)acrylates, urethane (meth)acrylates, carbonate (meth)acrylates, and epoxy (meth)acrylates. Specifically, diacrylates of glycols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, and propylene glycol; polyhydric alcohols such as hexanediol, trimethylolpropane, pentaerythritol, dipentaerythritol, and tris-hydroxyethyl isocyanurate, or polyhydric acrylates such as ethylene oxide adducts, propylene oxide adducts, or ε-caprolactone adducts of these; phenoxy acrylate, bisphenol A diacrylate, and ethylene oxide adducts or propylene oxide adducts of these phenols. polyhydric acrylates such as glycerin diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, triglycidyl isocyanurate, and other glycidyl ether polyacrylates; and, without being limited to the above, examples thereof include acrylates and melamine acrylates obtained by directly acrilating polyols such as polyether polyols, polycarbonate diols, hydroxyl group-terminated polybutadienes, and polyester polyols, or by urethane acrilation via diisocyanates, and at least one of the methacrylates corresponding to the above acrylates.

In particular, it is preferable that the (C) photopolymerizable multifunctional monomer includes (C1) an RO-addition photopolymerizable multifunctional monomer and (C2) a lactone-addition photopolymerizable multifunctional monomer. In the present invention, RO refers to alkylene oxide, and alkylene oxide includes ethylene oxide (EO) and propylene oxide (PO). In the present invention, lactone includes γ-butyrolactone, δ-valerolactone, ε-caprolactone, and methylated ε-caprolactone.

(C1) Examples of RO-added photopolymerizable polyfunctional monomers include ethylene oxide adducts and propylene oxide adducts of glycols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, and propylene glycol; and ethylene oxide adducts and propylene oxide adducts of polyhydric alcohols such as hexanediol, trimethylolpropane, pentaerythritol, dipentaerythritol, and tris-hydroxyethyl isocyanurate.

Examples of (C2) lactone-addition photopolymerizable polyfunctional monomers include ε-caprolactone adducts of glycols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, and propylene glycol; and ε-caprolactone adducts of polyhydric alcohols such as hexanediol, trimethylolpropane, pentaerythritol, dipentaerythritol, and tris-hydroxyethyl isocyanurate.

When the (C) photopolymerizable multifunctional monomer contains the (C1) RO-addition photopolymerizable multifunctional monomer and the (C2) lactone-addition photopolymerizable multifunctional monomer, the mass ratio (solid content) of the (C1) RO-addition photopolymerizable multifunctional monomer/(C2) lactone-addition photopolymerizable multifunctional monomer in the photocurable black composition of the present invention is in the range of 0.5 to 10, preferably in the range of 0.5 to 7, and particularly preferably in the range of 1 to 5. When the (C1) RO-addition photopolymerizable multifunctional monomer/(C2) lactone-addition photopolymerizable multifunctional monomer mass ratio (solid content) is in the range of 0.5 to 10, the resolution is good.

In addition, (C) the photopolymerizable polyfunctional monomer preferably has three or more ethylenically unsaturated groups in one molecule, and more preferably has three or more and six or less ethylenically unsaturated groups in one molecule.

The amount of (C) photopolymerizable polyfunctional monomer is in the range of 5 parts by mass or more and 50 parts by mass or less per 100 parts by mass (solids) of (A) alkali-soluble resin, and it is preferable that the ratio is 5 parts by mass or more and 40 parts by mass or less.

When the blend amount is 5 parts by mass or more and 50 parts by mass or less, the resolution is good.

In addition to the (C) photopolymerizable polyfunctional monomer, a photopolymerizable monofunctional monomer may be included. Examples of photopolymerizable monofunctional monomers include hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate.

Furthermore, the photocurable black composition of the present invention preferably contains (D) carbon black having a nitrogen adsorption specific surface area based on JIS K6217-2:2017 of 300 m ² /g or more.

[(D) Carbon black having a nitrogen adsorption specific surface area of 300 m ² /g or more based on JIS K6217-2:2017]
(D) Carbon black having a nitrogen adsorption specific surface area based on JIS K6217-2:2017 of 300 ^m2 /g or more provides the black shielding material (black coated substrate) obtained from the photocurable black composition with the necessary light-shielding properties and the effect of suppressing so-called white blur.

(D) Commercially available carbon black having a nitrogen adsorption specific surface area of 300 m ² /g or more based on JIS K6217-2:2017 includes #2300, #2350, #2600, and #2650 (all manufactured by Mitsubishi Chemical Corporation).

In addition, the nitrogen adsorption specific surface area based on JIS K6217-2:2017 is preferably 300 m ² /g or more and 400 m ² /g or less.

(D) The amount of carbon black having a nitrogen adsorption specific surface area of 300 ^m2 /g or more based on JIS K6217-2:2017 is in the range of 8 parts by mass or more and 40 parts by mass or less, preferably 10 parts by mass or more and 30 parts by mass or less, and particularly preferably 10 parts by mass or more and 20 parts by mass or less, relative to the total mass (solid content) of the photocurable black composition.

(D) When the amount of carbon black having a nitrogen adsorption specific surface area of 300 ^m2 /g or more based on JIS K6217-2:2017 is in the range of 8 parts by mass or more and 40 parts by mass or less relative to the total mass (solid content) of the photocurable black composition, it is possible to provide a photocurable black composition that can be photocured while maintaining the shielding properties required for a black shielding material (black coated substrate).

[(E) Ester of cellulose and short chain fatty acid]
The photocurable black composition of the present invention preferably contains (E) an ester of cellulose and a short-chain fatty acid. In the present invention, the short-chain fatty acid refers to one having 4 or less carbon atoms, and the ester of cellulose and a short-chain fatty acid includes not only one in which the hydrogen of the hydroxyl group of the cellulose molecule is completely substituted with an acyl group, but also one in which the hydroxyl group remains in the cellulose molecule.

(E) By including an ester of cellulose and a short-chain fatty acid in the photocurable black composition of the present invention, the development resistance is improved and the tackiness (dryness to the touch) of the cured product is also improved.

(E) Examples of esters of cellulose and short-chain fatty acids include cellulose acetate butyrate (CAB) and cellulose acetate propionate (CAP). Commercially available products of cellulose acetate butyrate (CAB) include CAB-551-0.01, CAB-551-0.2, CAB-553-0.4, CAB-381-0.1, and CAB-381-0.5 (all manufactured by Eastman Co.), and commercially available products of cellulose acetate propionate (CAP) include CAP-504-0.2 and CAP-482-0.5 (all manufactured by Eastman Co.).

(E) When an ester of cellulose and a short-chain fatty acid is blended, the blending amount is preferably in the range of 2 parts by mass or more and 15 parts by mass or less relative to the total mass (solid content) of the photocurable black composition.

(E) When the amount of ester of cellulose and short-chain fatty acid is in the range of 2 parts by mass or more and 15 parts by mass or less relative to the total mass (solid content) of the photocurable black composition, the development resistance is improved and the tackiness (dryness to the touch) of the cured product is improved.

[(F) Thermosetting component]
From the viewpoint of improving the heat resistance and shape stability of the cured product, the photocurable black composition of the present invention is preferably heat-cured in addition to photocuring. Therefore, the photocurable black composition of the present invention preferably contains a thermosetting component (F).

(F) As the thermosetting component, known and commonly used thermosetting resins such as isocyanate compounds (including blocked isocyanate compounds), amino resins, maleimide compounds, benzoxazine resins, carbodiimide resins, cyclocarbonate compounds, epoxy compounds, polyfunctional oxetane compounds, and episulfide resins can be used.

In the present invention, epoxy resins are particularly preferred.

As the epoxy resin, a known and commonly used multifunctional epoxy resin having at least two epoxy groups in one molecule can be used. The epoxy resin may be liquid, solid, or semi-solid. Here, liquid, solid, and semi-solid refer to the state of the epoxy resin at 30°C.

Examples of epoxy resins include jER828, jER834, jER1001, and jER1004 manufactured by Mitsubishi Chemical Corporation, EPICLON 840, EPICLON 850, EPICLON 850-S, EPICLON 1050, and EPICLON 2055 manufactured by DIC Corporation, Epotohto YD-011, YD-013, YD-127, and YD-128 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., and D.E.R. 317, D.E.R. 331, D.E.R. 661, and D.E.R. manufactured by The Dow Chemical Company. 664, bisphenol A type epoxy resins such as Sumiepoxy ESA-011, ESA-014, ELA-115, ELA-128 (all trade names) manufactured by Sumitomo Chemical Co., Ltd.; jERYL903 manufactured by Mitsubishi Chemical Co., Ltd., EPICLON 152, EPICLON 165 manufactured by DIC Corporation, Epotohto YDB-400, YDB-500 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., D.E.R. 542 manufactured by Dow Chemical Co., Ltd., Sumiepoxy ESB-400, ESB-700 (all trade names) and other brominated epoxy resins; jER152, jER154 manufactured by Mitsubishi Chemical Co., Ltd., D.E.N. 431, D.E.N. 542 manufactured by Dow Chemical Co., Ltd. ... 438, EPICLON N-730, EPICLON N-770, EPICLON N-865 manufactured by DIC Corporation, Epotohto YDCN-701, YDCN-704 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., EPPN-201, EOCN-1025, EOCN-1020, EOCN-104S, RE-306, NC-3000 manufactured by Nippon Kayaku Co., Ltd., Sumi-Epoxy ESCN-195X, ESCN-220 manufactured by Sumitomo Chemical Co., Ltd., YDCN-700-2, YDCN-700-3, YDCN-700-5, YDCN-700-7, YDCN-700-10, YDCN-704 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. Novolac type epoxy resins such as YDCN-704A, EPICLON N-680, EPICLON N-690, and EPICLON N-695 (all trade names) manufactured by DIC Corporation; EPICLON 830, jER807 manufactured by Mitsubishi Chemical Corporation, Epotohto YDF-170, YDF-175, YDF-2004, etc. (all trade names) of bisphenol F type epoxy resins manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.; hydrogenated bisphenol A type epoxy resins such as Epotohto ST-2004, ST-2007, ST-3000 (trade names) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., YX8034, etc. manufactured by Mitsubishi Chemical Corporation; glycidylamine type epoxy resins such as jER604 manufactured by Mitsubishi Chemical Corporation, Epotohto YH-434 manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., Sumiepoxy ELM-120, etc. (all trade names) of Sumitomo Chemical Co., Ltd.; hydantoin type epoxy resins; alicyclic epoxy resins such as CELLOXIDE 2021, etc. (all trade names) manufactured by Daicel Chemical Industries, Ltd.; YL-933 manufactured by Mitsubishi Chemical Corporation, T. Trihydroxyphenylmethane type epoxy resins such as E.N., EPPN-501, EPPN-502 (all trade names); bixylenol type or biphenol type epoxy resins or mixtures thereof such as YL-6056, YX-4000, YL-6121 (all trade names) manufactured by Mitsubishi Chemical Corporation; bisphenol S type epoxy resins such as EBPS-200 manufactured by Nippon Kayaku Co., Ltd., EPX-30 manufactured by ADEKA Corporation, and EXA-1514 (trade name) manufactured by DIC Corporation; bisphenol A novolac type epoxy resins such as jER157S (trade name) manufactured by Mitsubishi Chemical Corporation; tetraphenylolethane type epoxy resins such as jERYL-931 (all trade names) manufactured by Mitsubishi Chemical Corporation; heterocyclic epoxy resins such as TEPIC (all trade names) manufactured by Nissan Chemical Industries, Ltd.; Bress-1000 (trade name) manufactured by NOF Corporation; diglycidyl phthalate resins such as NMA DGT; tetraglycidyl xylenoylethane resins such as ZX-1063 manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd.; naphthalene group-containing epoxy resins such as ESN-190 and ESN-360 manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., and HP-4032, EXA-4750, and EXA-4700 manufactured by DIC Corporation; epoxy resins having a dicyclopentadiene skeleton such as HP-7200 and HP-7200H manufactured by DIC Corporation; glycidyl methacrylate copolymer epoxy resins such as CP-50S and CP-50M manufactured by NOF Corporation; further, copolymer epoxy resins of cyclohexylmaleimide and glycidyl methacrylate; and CTBN-modified epoxy resins (for example, YR-102 and YR-450 manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd.), but are not limited thereto.

These epoxy resins are liquid, solid, or semi-solid at 30°C, and may be used alone or in combination of two or more. Epoxy resins may also be used in combination with other known and commonly used thermosetting components.

When (F) a thermosetting component is blended, the blending amount is preferably in the range of 30 parts by mass or more and 120 parts by mass or less, and more preferably in the range of 40 parts by mass or more and 80 parts by mass or less, per 100 parts by mass (solids) of the alkali-soluble resin (A).

[Leveling agent]
The photocurable black composition of the present invention preferably contains a leveling agent. The leveling agent adjusts the fluidity of the photocurable black composition and flattens the coating film of the photocurable black composition. Examples of the leveling agent include a surfactant, and among them, it is preferable to use a leveling agent containing a polyacrylate compound as a main component.

Commercially available leveling agents whose main component is a polyacrylate compound include BYK-350, BYK-354, BYK-355, BYK-356, BYK-358N, BYK-361N, BYK-381, BYK-392, BYK-394, and BYK-3441 (all manufactured by BYK Japan; BYK is a registered trademark).

When the photocurable black composition of the present invention contains a leveling agent, the amount of the leveling agent is preferably in the range of 0.05 parts by mass or more and 5 parts by mass or less, and more preferably in the range of 0.1 parts by mass or more and 3 parts by mass or less, relative to the total mass (solids content) of the photocurable black composition.

[Other ingredients]
The photocurable black composition of the present invention may further contain, as necessary, known and commonly used additives such as known and commonly used polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, t-butylcatechol, pyrogallol, and phenothiazine; known and commonly used inorganic fillers such as barium sulfate, barium titanate, silicon oxide powder, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, and mica powder; known and commonly used thickeners such as finely powdered silica, organic bentonite, and montmorillonite; silicone-based and fluorine-based defoamers; antioxidants, photopolymerization sensitizers, light stabilizers, dispersants, curing accelerators, flame retardants, and flame retardant assistants.

In addition, the photocurable black composition of the present invention may contain an organic solvent used for preparing the photocurable black composition or adjusting the viscosity. Examples of organic solvents that can be used include ketones such as methyl ethyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; glycol ethers such as cellosolve, methyl cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether (DPM), dipropylene glycol diethyl ether, and tripropylene glycol monomethyl ether; esters such as ethyl acetate, butyl acetate, butyl lactate, cellosolve acetate, butyl cellosolve acetate, carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and propylene carbonate; aliphatic hydrocarbons such as octane and decane; and petroleum-based solvents such as petroleum ether, petroleum naphtha, and solvent naphtha. These organic solvents can be used alone or in combination of two or more.

The photocurable black composition of the present invention may be prepared as a one-liquid system or may be formulated as a two-liquid system. When it is a two-liquid system, the (B) photopolymerization initiator is blended in a liquid separate from the liquid containing the (A) alkali-soluble resin and (C) photopolymerizable polyfunctional monomer. This is to prevent undesired photopolymerization reactions during storage.

The photocurable black composition of the present invention can suppress the occurrence of white blur, so that a high-quality, high-quality display member with improved visibility can be obtained. The photocurable black composition of the present invention can also be used to produce shielding images such as printing inks, materials for producing printing proofs, etching resists, solder resists, partitions of organic or inorganic EL display panels, dielectric patterns, electrode (conductor circuit) patterns, wiring patterns of electronic components, conductive pastes, conductive films, black matrices, black seal materials, and black mask materials. In particular, the photocurable black composition of the present invention can be suitably used to provide a light-shielding image (including a black matrix) in the gaps and periphery of a colored pattern and on the external light side of a TFT in order to improve the visibility of a color filter used in a color liquid crystal display device or the like, or as a light-shielding film for a touch panel. Particularly preferably, the film is used as a black edge (bezel formation) provided in the periphery of a liquid crystal display device, an EL display device having an organic or inorganic EL, or a display device having a touch panel, or as a lattice-like or stripe-like black portion between red, blue, and green colored pixels, and more preferably as a black matrix such as a dot-like or line-like black pattern for TFT light shielding.

<Cured product of the photocurable black composition of the present invention, and black-coated substrate>
The black coated substrate of the present invention comprises a transparent substrate and a cured coating (cured product) of the photocurable black composition of the present invention applied onto the transparent substrate.

The transparent substrate is a substrate with a total light transmittance of 50% or more in the range of 400 to 800 nm. Specific examples include glass substrates, or resin substrates such as polyethylene naphthalate (PEN), polyethylene terephthalate (PET), and polyimide (PI), and the substrate may have a shape ranging from a plate-like shape to a thin film-like shape. The plate-like shape is not limited to a flat plate-like shape, and may also be a concave or convex lens shape, or a curved shape.

The photocurable black composition of the present invention can be in the form of a dry film obtained by applying it to a carrier film (support) and drying it. When making it into a dry film, the photocurable black composition of the present invention is diluted with the above-mentioned organic solvent to adjust the viscosity to an appropriate level, and applied to a uniform thickness on a carrier film using a comma coater, blade coater, lip coater, rod coater, squeeze coater, reverse coater, transfer roll coater, gravure coater, spray coater, or the like, and typically dried at a temperature of 50 to 130°C for 1 to 30 minutes to obtain a dried coating film. There are no particular restrictions on the coating film thickness, but it is generally selected appropriately in the range of 0.1 to 100 μm, preferably 0.5 to 50 μm, in terms of the film thickness after drying.

As the carrier film, a plastic film is used, and it is preferable to use a plastic film such as a polyester film such as polyethylene terephthalate, a polyimide film, a polyamideimide film, a polypropylene film, or a polystyrene film. There is no particular restriction on the thickness of the carrier film, but it is generally selected appropriately in the range of 0.1 to 150 μm.

In this case, after forming the coating film on the carrier film, it is preferable to further laminate a peelable cover film on the surface of the coating film for the purpose of preventing dust from adhering to the surface of the coating film. Examples of the peelable cover film that can be used include polyethylene film, polytetrafluoroethylene film, polypropylene film, and surface-treated paper. When peeling off the cover film, the adhesive strength between the coating film and the cover film should be smaller than the adhesive strength between the coating film and the carrier film.

In addition, the photocurable black composition of the present invention is adjusted to a viscosity suitable for the coating method using the organic solvent, and then coated on a transparent substrate by a method such as spray coating, dip coating, flow coating, roll coating, bar coating, screen printing, curtain coating, or die coating, and the organic solvent contained in the composition is evaporated and dried (pre-dried) at a temperature of about 50°C to 90°C to form a tack-free dry coating film. In addition, in the case of a dry film in which the photocurable black composition of the present invention is coated on a carrier film, dried, and wound up as a film, this can be laminated on a transparent substrate by a laminator or the like so that the coating film of the photocurable black composition is in contact with the transparent substrate, and then the carrier film can be peeled off to form a coating layer on the substrate.

A cured coating can be obtained by photocuring these coating films, for example, by irradiation with active energy rays, and, if a thermosetting component (F) is contained, by further heat curing at a temperature of 100°C to 250°C. In other words, a black-coated substrate is obtained that has a transparent substrate and a cured coating (cured product) of the photocurable black composition of the present invention applied onto the transparent substrate.

The volatilization drying carried out after application of the photocurable black composition of the present invention can be carried out by using a method in which hot air in a dryer equipped with a heat source that uses steam for air heating, such as a hot air circulation drying oven, IR oven, hot plate, or convection oven, is brought into countercurrent contact with the substrate, or by spraying the substrate from a nozzle.

The exposure machine used for the active energy ray irradiation may be a machine equipped with a high pressure mercury lamp, an ultra-high pressure mercury lamp, a metal halide lamp, a mercury short arc lamp, or the like, and irradiates ultraviolet rays in the range of 350 to 450 nm, and further, a direct imaging machine (for example, a direct imaging machine that directly irradiates active energy rays to draw an image based on CAD data from a computer) may also be used. The light source of the direct imaging machine may be one that uses light with a maximum wavelength in the range of 350 to 410 nm. The exposure dose for image formation varies depending on the film thickness, etc., but can generally be within the range of 20 to 1000 mJ/cm ² , preferably 20 to 800 mJ/cm ² .

The development method can be a dipping method, a shower method, a spray method, a brush method, etc., and the developer can be an alkaline aqueous solution of potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate, sodium phosphate, sodium silicate, ammonia, amines, etc.

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In the following, "parts" refers to parts by mass unless otherwise specified.

1. Preparation of photocurable black compositions of Examples 1 to 7 and Comparative Examples 1 to 3
The materials shown in Table 1 were blended and mixed with a stirrer to prepare a first liquid, and the materials shown in Table 1 were blended and mixed with a stirrer to prepare a second liquid. Thereafter, the first and second liquids were mixed and stirred to prepare a photocurable black composition.

*1: High-boiling point solvent dilution product of radical curing acrylic polymer containing acryloyl and carboxyl groups (solid content 46%) (Cyclomer P (ACA) Z250: manufactured by Daicel Allnex Corporation)
*2: 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Omnirad TPO H: manufactured by IGM Resins B.V.)
*3: EO-added trimethylolpropane triacrylate (Laromer LR8863: manufactured by BASF Japan)
*4: ε-caprolactone-modified dipentaerythritol hexaacrylate (DPCA-60: manufactured by Nippon Kayaku Co., Ltd.)
*5: Carbon black with a nitrogen adsorption specific surface area of 370 ^m2 /g (#2650: manufactured by Mitsubishi Chemical Corporation)
*6: Carbon black with a nitrogen adsorption specific surface area of 320 m ² /g (#2350: manufactured by Mitsubishi Chemical Corporation)
*7: Carbon black with a nitrogen adsorption specific surface area of 260 m ² /g (#980: manufactured by Mitsubishi Chemical Corporation)
*8: Carbon black with a nitrogen adsorption specific surface area of 88 m ² /g (#52: manufactured by Mitsubishi Chemical Corporation)
*9: Cellulose acetate butyrate diluted with DPM (dipropylene glycol monomethyl ether) (solid content 30%) (CAB-551-0.2: manufactured by Eastman Chemical Co.)
*10: Leveling agent whose main component is a polyacrylate compound (BYK-361N: manufactured by BYK Japan)
*11: Dipropylene glycol monomethyl ether
*12: Propylene glycol monomethyl ether
*13: Solid bisphenol A type epoxy resin (jER (registered trademark) 1001: manufactured by Mitsubishi Chemical Corporation) diluted with carbitol acetate (solid content 75%)
*14: Liquid hydrogenated bisphenol A type epoxy resin (YX8034: manufactured by Mitsubishi Chemical Corporation)
*15: Dimeric oxime ester photopolymerization initiator (TOE-04-A3: manufactured by Nippon Chemical Industry Co., Ltd.)
*16: Propylene carbonate

2. Preparation of cured coating (cured product) and its evaluation
2-1. Preparation of cured coating (cured product) The surface of a glass substrate (Eagle XG 1.1 mm thick, manufactured by Corning) was degreased with alcohol, and the photocurable black compositions prepared in Examples 1 to 7 and Comparative Examples 1 to 3 were applied to the degreased surface using a spray coater (air spray method) so that the dry film thickness was about 10 μm. The composition was then dried at 90° C. for 30 minutes in a hot air circulation drying oven, and exposed to ultraviolet light at 1500 mJ/cm ² using an exposure device (HMW680GW, manufactured by ORC Corporation).

Then, a 1 mass % _{Na2CO3 aqueous} solution at 30°C was sprayed at a spray pressure of 0.2 MPa for 60 seconds to perform development, followed by post-UV treatment at 1000 mj/ ^cm2 in a UV conveyor furnace and post-curing at 150°C for 1 hour to form a black-coated substrate having a glass substrate and a cured coating (cured product) of the photocurable black composition applied on the glass substrate.

2-2. OD value (optical density)
The cured coating side of the black-coated substrate formed in "2-1. Preparation of cured coating (cured product)" was attached to a transmission densitometer (X-Rite 361T, manufactured by Sakata Inx Engineering Co., Ltd.) to evaluate the OD value. The black-coated substrate was attached to the transmission densitometer with the glass substrate side facing the light source.

2-3. Reflectance (Y value) SCE/SCI (%)
For the black coated substrate formed in "2-1. Preparation of cured coating (cured product)", the Y value of the XYZ color system was measured using a color difference meter (CM-2600d (light source wavelength: 360-740 nm), manufactured by Konica Minolta). The Y value was measured using the SCE (specular reflected light excluded) method, which is an evaluation of color close to that seen with the naked eye because specular reflected light is removed and only diffuse reflected light is measured, and the SCI (specular reflected light included) method, which is an evaluation of the color of the material itself regardless of the surface condition because specular reflected light is included in the measurement. The measurements were performed on the glass substrate surface of the black coated substrate.

The lower the reflectance (Y value) SCE/SCI (%), the more the occurrence of white blur is suppressed.

2-4. Resolution A black coated substrate was formed under the same conditions as those in "2-1. Preparation of cured film (cured product)" except that a negative pattern with a line width of 20 to 300 μm in the light-shielded portion was used during exposure.

For each of the black coated substrates formed in Examples 1 to 7 and Comparative Examples 1 to 3, the width of the linear cured product remaining on the glass substrate was measured, and the smallest width of the remaining linear cured product was recorded as the evaluation item for resolution (L/S). The smaller the resolution (L/S) width, the better the resolution that allows for the formation of finer lines, which is evaluated as a photocurable black composition.

2-5. Developability A black coated substrate was formed under the same conditions as those in "2-1. Preparation of cured film (cured product)" except that a negative pattern with a line width of 20 to 300 μm in the light-shielded portion was used during exposure.

For each of the black-coated substrates formed in Examples 1 to 7 and Comparative Examples 1 to 3, the area on the glass substrate that was covered by the light-shielding portion of the negative pattern, was left unexposed, and was developed with an alkali. The area was visually observed to evaluate whether development residue was observed. The evaluation criteria were as follows.
: No residue was observed.
○: Some residue was observed.
×: Residue was observed throughout the entire surface.

2-6. Tackiness Each of the photocurable black compositions of Examples 1 to 7 and Comparative Examples 1 to 3 was applied to the entire surface of a glass substrate by screen printing, dried in a hot air circulation type drying oven at 90°C for 30 minutes, and allowed to cool to room temperature. A PET film was pressed onto the glass substrate on which the photocurable black composition had been applied, and the film was then peeled off to evaluate the state of adhesion. The evaluation criteria were as follows:
⊚: The film does not stick at all.
◯: The film sticks slightly, but no pressure marks remain on the ink.
△: Pressure marks from the film remain on the ink.
×: Ink transfers to the film.

The evaluation results for OD value (optical density), reflectance, resolution, developability and tackiness are shown in Table 2 below.

As shown in Table 2, the reflectance (Y value) SCE/SCI (%) of Examples 1 and 2 is very small compared to Comparative Examples 1 and 2, which shows that white blur is suppressed when carbon black with a nitrogen adsorption specific surface area of 300 ^m2 /g or more is used. Moreover, the tackiness of Example 1 is improved compared to Example 5, which shows that the incorporation of (E) an ester of cellulose and a short-chain fatty acid improves the tackiness.

Claims (7)

(A) an alkali-soluble resin;
(B) a photopolymerization initiator;
(C) a photopolymerizable multifunctional monomer;
(D) carbon black having a nitrogen adsorption specific surface area based on JIS K6217-2:2017 of 300 m ² /g or more;
(E) an ester of cellulose and a short chain fatty acid;
1. A photocurable black composition comprising: 2. The photocurable black composition according to claim 1 , wherein the photopolymerizable multifunctional monomer (C) comprises (C1) an RO addition photopolymerizable multifunctional monomer and (C2) a lactone addition photopolymerizable multifunctional monomer. 3. The photocurable black composition according to claim 2 , wherein a mass ratio (solid content) of the RO addition photopolymerizable multifunctional monomer (C1) to the lactone addition photopolymerizable multifunctional monomer (C2) is in the range of 0.5 or more and 10 or less. 3. The photocurable black composition according to claim 1, wherein the carbon black (D) has a nitrogen adsorption specific surface area based on JIS K6217-2:2017 of 300 m ² /g or more and 400 m ² /g or less. The photocurable black composition according to any one of claims 1 to 4 , further comprising: (F) a thermosetting component. A cured product of the photocurable black composition according to any one of claims 1 to 5 . A black coated substrate comprising a transparent substrate and a cured coating of the photocurable black composition according to any one of claims 1 to 5 applied onto the transparent substrate.