JP7737809B2 - Photosensitive resin composition for black resist, light-shielding film, and method for producing light-shielding film for color filter - Google Patents

Description

The present invention relates to a photosensitive resin composition for black resist, a light-shielding film, and a method for producing a light-shielding film for a color filter.

A color LCD panel consists of a substrate with a color filter and an opposing substrate (TFT substrate) bonded together via a sealant, with liquid crystal filled between the two substrates. Color filters are typically manufactured by forming a black matrix on the surface of a transparent substrate such as glass or a plastic sheet, which serves to improve contrast by suppressing color mixing between the red, green, and blue colors. Then, different hues of red, green, and blue, which serve to express all natural colors, are sequentially formed in a color pattern such as a stripe or mosaic.

In recent years, there has been a trend toward narrower frame widths for LCD displays, which in turn reduces the area required for bonding the sealant used to seal the LCD. This has created a demand for improved adhesion strength at the interface between the black matrix and glass substrate. This means that adhesion strength must be maintained even after durability tests (reliability tests), such as a pressure cooker test (PCT). The PCT test involves exposing the LCD panel to harsh conditions of a temperature of 120°C, humidity of 100%, and atmospheric pressure of 2 atm for several hours.

The black matrix not only improves the contrast of the LCD display, but also functions as an outer frame light-shielding film for the color filter. A portion of the outer frame light-shielding film is bonded to the opposing substrate (glass substrate) via a sealant. Therefore, the black matrix is required to have high adhesion strength to the glass substrate, even when subjected to harsh conditions such as the durability test (PCT) mentioned above.

In recent years, there has also been a growing need for higher light-blocking capabilities to improve the visibility of LCD panels. One way to achieve higher light-blocking capabilities is to increase the thickness of the black matrix; however, if the thickness is made too thick, the film thickness will increase where the black matrix overlaps with the red, green, and blue pixels when they are formed in the subsequent manufacturing process, resulting in so-called "corner steps." These "corner steps" can cause liquid crystal alignment problems and reduce panel visibility, so there is a demand for thinner black matrices with higher light-blocking capabilities.

Here, if the content of black pigment in the resin composition is increased to achieve a thinner black matrix and higher light-shielding properties, the blending ratio of binder resin, acrylate components, and other components that contribute to curing becomes relatively small, making it difficult for the coating film to cure sufficiently. As a result, adhesion between the coating film and the glass substrate decreases, making peeling more likely to occur. Furthermore, if the light-shielding film's light-shielding ability increases, radiation (e.g., ultraviolet light) does not reach the depths of the coating film during exposure. This causes differences in the way the surface and deeper portions of the coating film that have hardened upon exposure shrink during post-baking, making wrinkles more likely to occur on the surface of the light-shielding film. Therefore, if another layer is formed on the surface of the light-shielding film, concerns arise not only about the adhesion between the light-shielding film and the other layer, but also about adverse effects on the manufacturing process. As such, demands for adhesion between the black matrix and the substrate have become even more stringent in recent years.

For example, Patent Document 1 discloses a photosensitive resin composition containing an alkali-soluble resin having an acryloyl group or an epoxy group, a photopolymerizable compound having a specific structure, and a photopolymerization initiator. Patent Document 1 claims to provide a photosensitive resin composition capable of forming patterns with a good cross-sectional shape, excellent linearity, and excellent adhesion to the substrate.

JP 2015-212738 A

However, according to the findings of the present inventors, when the pigment concentration of conventional photosensitive resin compositions is increased to, for example, 40% by mass or more, the desired adhesion may not be achieved. Furthermore, desired patterning properties such as exposure sensitivity and alkaline developability may not be achieved. A decrease in developer solubility can have an impact on productivity, resulting in reduced yield due to pattern chipping and a longer development process time.

An object of the present invention is to provide a photosensitive resin composition for black resist that can form a light-shielding film that has good adhesion to a glass substrate even after PCT, high exposure sensitivity, excellent pattern linearity, volume resistivity, and light-shielding degree, and has a good cross-sectional shape. Another object of the present invention is to provide a method for producing a light-shielding film for a color filter using this photosensitive resin composition, which can shorten the time required for the development process.

The inventors therefore discovered that by using a photosensitive resin composition containing an alkali-soluble resin, an alkylene oxide group or a group having a lactone ring-opened structure, and a photopolymerizable compound having at least two ethylenically unsaturated bonds, an acrylic equivalent of 90 g/eq or more and 400 g/eq or less, and a molecular weight of 200 or more and 5000 or less, it is possible to form a light-shielding film that exhibits even higher adhesion, has high exposure sensitivity, is excellent in pattern linearity, volume resistivity, and light-shielding degree, and has a good cross-sectional shape, and thus completed the present invention.

The photosensitive resin composition for black resist according to the present invention comprises (a) an alkali-soluble resin, (b) a photopolymerizable compound having an alkylene oxide group or a group having a lactone ring-opened structure and at least two ethylenically unsaturated bonds, (c) a photopolymerization initiator, (d) a light-blocking agent, and (e) a solvent, wherein the (b) component has an acrylic equivalent of 90 g/eq or more and 400 g/eq or less and a molecular weight of 200 or more and 5,000 or less.

The light-shielding film of the present invention is obtained by curing the above-mentioned photosensitive resin composition for black resist.

The method for producing a color filter light-shielding film according to the present invention comprises a coating film formation step of applying the above-mentioned photosensitive resin composition for black resist to a transparent substrate and drying to form a coating film of the photosensitive resin composition for black resist; an exposure step of irradiating a portion of the coating film with radiation through a photomask; a development step of developing the irradiated coating film and removing the unexposed portions; and a heat-curing step of heat-curing the developed coating film.

The present invention provides a photosensitive resin composition for black resist that can form a light-shielding film that has good adhesion to a glass substrate even after PCT, high exposure sensitivity, excellent pattern linearity, volume resistivity, and light-shielding degree, and has a good cross-sectional shape. It is also an object of the present invention to provide a method for producing a light-shielding film for a color filter using the photosensitive resin composition, which can shorten the time required for the development process.

The photosensitive resin composition for black resist of the present invention is described in detail below.

The photosensitive resin composition for black resist of the present invention contains (a) an alkali-soluble resin, (b) a photopolymerizable compound having an alkylene oxide group or a group having a lactone ring-opened structure and at least two ethylenically unsaturated bonds, (c) a photopolymerization initiator, (d) a light-blocking agent, and (e) a solvent.

1. Photosensitive resin composition [(a) component]
The component (a) is an alkali-soluble resin. By including the component (a), the photosensitive resin composition can be made soluble in alkali development.

The alkali-soluble resin, component (a), preferably contains a polymerizable unsaturated group and an acidic group in each molecule to achieve alkali solubility, and more preferably contains both a polymerizable unsaturated group and a carboxy group. Any of the above resins can be used without any particular limitations. Because the alkali-soluble resin contains both a polymerizable unsaturated group and a carboxy group, it functions as a binder and provides excellent photocurability to the photosensitive resin composition for black resist. It also provides good developability and patterning properties (pattern line width, pattern linearity), improving the physical properties of the light-shielding film.

The alkali-soluble resin, component (a) in this embodiment, is preferably a polymerizable unsaturated group-containing alkali-soluble resin obtained by further reacting a reaction product of an epoxy compound having two or more epoxy groups with (meth)acrylic acid with a polybasic carboxylic acid or its anhydride. During the production of the alkali-soluble resin, a polyester is produced by the reaction of a hydroxy group with a polybasic carboxylic acid, and the average degree of polymerization is preferably a low molecular weight of approximately 2 to 500. Note that "(meth)acrylic acid" is a general term for acrylic acid and methacrylic acid, and "(meth)acryloyl group" is a general term for an acryloyl group and a methacryloyl group, meaning either or both of these.

Examples of epoxy compounds having two or more epoxy groups include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol fluorene type epoxy compounds, bisnaphthol fluorene type epoxy compounds, diphenyl fluorene type epoxy compounds, phenol novolac type epoxy compounds, (o, m, p-) cresol novolac type epoxy compounds, phenol aralkyl type epoxy compounds, biphenyl type epoxy compounds, phenol novolac compounds containing a naphthalene skeleton (e.g., NC-7000L, manufactured by Nippon Kayaku Co., Ltd.), naphthol aralkyl type epoxy compounds, trisphenol methane type epoxy compounds (e.g., EPPN-501H, manufactured by Nippon Kayaku Co., Ltd.), epoxy compounds with an aromatic structure such as tetrakisphenol ethane type epoxy compounds, and glycidyl polyhydric alcohols. ethers, glycidyl esters of polycarboxylic acids, copolymers of monomers having a (meth)acryloyl group containing glycidyl (meth)acrylate as a unit, such as copolymers of methacrylic acid and glycidyl methacrylate, epoxy compounds having a glycidyl group, such as hydrogenated bisphenol A diglycidyl ether (for example, Rikaresin HBE-100, manufactured by New Japan Chemical Co., Ltd., "Rikaresin" is a registered trademark of the company), 1,4-cyclohexanedimethanol-bis-3,4-epoxycyclohexanecarboxylate, 2-(3,4-epoxy)cyclohexyl-5,1-spiro(3,4-epoxy)cyclohexyl-m-dioxane (for example, Araldite CY175, manufactured by Huntsman, "Araldite" is a registered trademark of the company), bis(3,4-epoxycyclohexylmethyl)adipate (for example, CYRACURE UVR-6128: manufactured by Dow Chemical Company), 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (for example, Celloxide 2021P: manufactured by Daicel Corporation, "Celloxide" is a registered trademark of the company), butanetetracarboxylic acid tetra(3,4-epoxycyclohexylmethyl)-modified ε-caprolactone (for example, Epolead GT401: manufactured by Daicel Corporation, "Epolead" is a registered trademark of the company), epoxy compounds having an epoxycyclohexyl group (for example, HiREM-1: manufactured by Shikoku Chemical Industry Co., Ltd.), These include polyfunctional epoxy compounds having a dicyclopentadiene skeleton (e.g., HP7200 series: manufactured by DIC Corporation), alicyclic epoxy compounds such as 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol (e.g., EHPE3150: manufactured by Daicel Corporation), epoxidized polybutadiene (e.g., NISSO-PB JP-100: manufactured by Nippon Soda Co., Ltd., "NISSO-PB" is a registered trademark of the company), and epoxy compounds having a silicone skeleton.

Among the above epoxy compounds, bisphenol-type epoxy compounds represented by the following general formula (2), phenol novolac-type epoxy compounds represented by the following general formula (4), and (o-, m-, p-)cresol novolac-type epoxy compounds are preferred.

In formula (2), R ₆ and R ₇ independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 5 carbon atoms, or a halogen atom; W represents —CO—, —SO ₂ —, —C(CF ₃ ) ₂ —, —Si(CH ₃ ) ₂ —, —CH ₂ —, —C(CH ₃ ) ₂ —, —O—, a fluorene-9,9-diyl group represented by the following general formula (3), or a single bond; and n is an integer of 0 or more and 10 or less.

In formula (4), R ₈ to R ₁₁ independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 5 carbon atoms, a cycloalkyl group having 5 to 9 carbon atoms, or an aryl group having 6 to 10 carbon atoms; R ₁₂ to R ₂₂ independently represent a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 5 carbon atoms, an alkenyl group having 1 to 5 carbon atoms, an alkynyl group having 1 to 5 carbon atoms, a cycloalkyl group having 5 to 9 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms; and o represents an integer of 1 to 5.

From the viewpoints of developability and fine line adhesion, bisphenol-type epoxy compounds represented by general formula (2) are more preferred.

The bisphenol-type epoxy compound represented by the general formula (2) above is derived from a bisphenol. Examples of the bisphenol include bis(4-hydroxyphenyl)ketone, bis(4-hydroxy-3,5-dimethylphenyl)ketone, bis(4-hydroxy-3,5-dichlorophenyl)ketone, bis(4-hydroxyphenyl)sulfone, bis(4-hydroxy-3,5-dimethylphenyl)sulfone, bis(4-hydroxy-3,5-dichlorophenyl)sulfone, bis(4-hydroxyphenyl)hexafluoropropane, bis(4-hydroxy-3,5-dimethylphenyl)hexafluoropropane, bis(4-hydroxy-3,5-dichlorophenyl)sulfone, bis(4-hydroxy ... phenyl)hexafluoropropane, bis(4-hydroxyphenyl)dimethylsilane, bis(4-hydroxy-3,5-dimethylphenyl)dimethylsilane, bis(4-hydroxy-3,5-dichlorophenyl)dimethylsilane, bis(4-hydroxyphenyl)methane, bis(4-hydroxy-3,5-dichlorophenyl)methane, bis(4-hydroxy-3,5-dibromophenyl)methane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 2,2-bis(4-hydroxy-3 ,5-dichlorophenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, 2,2-bis(4-hydroxy-3-chlorophenyl)propane, bis(4-hydroxyphenyl)ether, bis(4-hydroxy-3,5-dimethylphenyl)ether, bis(4-hydroxy-3,5-dichlorophenyl)ether, 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 9,9-bis(4-hydroxy-3-chlorophenyl)fluorene, 9,9-bis[4- (2-hydroxyethoxy)phenyl)fluorene, 9,9-bis(4-hydroxy-3-bromophenyl)fluorene, 9,9-bis(4-hydroxy-3-fluorophenyl)fluorene, 9,9-bis(4-hydroxy-3-methoxyphenyl)fluorene, 9,9-bis(4-hydroxy-3,5-dimethylphenyl)fluorene, 9,9-bis(4-hydroxy-3,5-dichlorophenyl)fluorene, 9,9-bis(4-hydroxy-3,5-dibromophenyl)fluorene, 4,4'-biphenol, 3,3'-biphenol, and the like. Among these, bisphenols having a fluorene-9,9-diyl group are preferred from the viewpoint of further improving heat resistance. These bisphenols may be used alone or in combination of two or more.

In addition, the polybasic carboxylic acid or anhydride used to obtain component (a) is preferably a combination of (A) a dicarboxylic acid or tricarboxylic acid or an acid monoanhydride and (B) a tetracarboxylic acid or an acid dianhydride.

(A) Examples of dicarboxylic acids or tricarboxylic acids or acid monoanhydrides thereof include open-chain hydrocarbon dicarboxylic acids or tricarboxylic acids, alicyclic dicarboxylic acids or tricarboxylic acids, aromatic dicarboxylic acids or tricarboxylic acids, or acid monoanhydrides thereof, etc.

Examples of open-chain hydrocarbon dicarboxylic or tricarboxylic acids include succinic acid, acetylsuccinic acid, maleic acid, adipic acid, itaconic acid, azelaic acid, citramalic acid, malonic acid, glutaric acid, citric acid, tartaric acid, oxoglutaric acid, pimelic acid, sebacic acid, suberic acid, diglycolic acid, and other dicarboxylic or tricarboxylic acids, as well as dicarboxylic or tricarboxylic acids having any substituent introduced therein.

Examples of alicyclic dicarboxylic or tricarboxylic acids include dicarboxylic or tricarboxylic acids such as cyclobutanedicarboxylic acid, cyclopentanedicarboxylic acid, hexahydrophthalic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, methyl-3,6-endomethylenetetrahydrophthalic acid, chlorendic acid, hexahydrotrimellitic acid, and norbornanedicarboxylic acid, as well as dicarboxylic or tricarboxylic acids having any substituent introduced therein.

Examples of aromatic dicarboxylic or tricarboxylic acids include dicarboxylic or tricarboxylic acids such as phthalic acid, isophthalic acid, trimellitic acid, 1,8-naphthalenedicarboxylic acid, and 2,3-naphthalenedicarboxylic acid, as well as dicarboxylic or tricarboxylic acids having any substituent introduced therein.

For dicarboxylic acids or tricarboxylic acids, it is preferable to use their acid monoanhydrides. The above-mentioned dicarboxylic acids or tricarboxylic acids or their acid monoanhydrides may be used alone or in combination of two or more types.

(B) Examples of tetracarboxylic acids or their dianhydrides include open-chain hydrocarbon tetracarboxylic acids, alicyclic tetracarboxylic acids, aromatic tetracarboxylic acids, and their dianhydrides.

Examples of open-chain hydrocarbon tetracarboxylic acids include tetracarboxylic acids such as butanetetracarboxylic acid, pentanetetracarboxylic acid, and hexanetetracarboxylic acid, as well as tetracarboxylic acids having any substituent introduced therein.

Examples of alicyclic tetracarboxylic acids include tetracarboxylic acids such as cyclobutane tetracarboxylic acid, cyclopentane tetracarboxylic acid, cyclohexane tetracarboxylic acid, cycloheptane tetracarboxylic acid, and norbornane tetracarboxylic acid, as well as tetracarboxylic acids having any substituent introduced therein.

Examples of aromatic tetracarboxylic acids include tetracarboxylic acids such as pyromellitic acid, benzophenone tetracarboxylic acid, biphenyl tetracarboxylic acid, diphenyl ether tetracarboxylic acid, diphenyl sulfone tetracarboxylic acid, naphthalene-1,4,5,8-tetracarboxylic acid, and naphthalene-2,3,6,7-tetracarboxylic acid, as well as tetracarboxylic acids having any substituent introduced therein.

Of the above-mentioned tetracarboxylic acids or acid dianhydrides, it is preferable to use the acid dianhydrides. The above-mentioned tetracarboxylic acids or acid dianhydrides may be used alone or in combination of two or more types.

In this case, the molar ratio (A)/(B) of (A) dicarboxylic acid or tricarboxylic acid or its monoanhydride to (B) tetracarboxylic acid or its dianhydride is preferably 0.01 or more and 10.0 or less, and more preferably 0.02 or more and less than 3.0. When the molar ratio (A)/(B) is within the above range, it is possible to obtain the optimal molecular weight for producing a photosensitive resin composition with good photopatterning properties. Note that the smaller the molar ratio (A)/(B), the larger the molecular weight and the lower the alkali solubility tends to be.

The reaction between the epoxy compound and (meth)acrylic acid, and the reaction between the epoxy (meth)acrylate obtained by this reaction and a polybasic acid or its acid anhydride, are not particularly limited, and known methods such as those described in JP-A-8-278629 can be used.

In addition, from the perspective of adjusting the dissolution rate, the alkali-soluble resin synthesized by the above reaction preferably has a weight-average molecular weight (Mw) of 1,000 to 20,000, more preferably 2,000 to 10,000, and preferably an acid value of 30 mgKOH/g to 200 mgKOH/g. The weight-average molecular weight of the alkali-soluble resin can be determined, for example, using a gel permeation chromatography (GPC) "HLC-8220GPC" (manufactured by Tosoh Corporation). The acid value can be determined, for example, using a potentiometric titrator "COM-1600" (manufactured by Hiranuma Sangyo Co., Ltd.).

The alkali-soluble resin (component (a)) may be used alone or in combination of two or more types.

[(b) Component]
The component (b) is a photopolymerizable compound. By including the component (b), it is possible to improve the exposure sensitivity and developability.

The photopolymerizable compound, component (b) in this embodiment, has an alkylene oxide group or a group having a lactone ring-opened structure and at least two ethylenically unsaturated bonds.

The photopolymerizable compound (b), component (b), preferably has at least one alkylene oxide group having 2 to 6 carbon atoms or a group having a ring-opened structure of a lactone having 2 to 6 carbon atoms (hereinafter simply referred to as a "lactone group"), and more preferably has an alkylene oxide group having 2 to 3 carbon atoms or a lactone group having 4 to 6 carbon atoms. Because the alkylene oxide group or lactone group contains a single-bonded oxygen atom, the lone electron pair of the oxygen atom suppresses steric hindrance, allowing the alkylene oxide group or lactone group to freely rotate within the molecule. This imparts flexibility to the coating film and relieves internal stress generated by thermal curing shrinkage, thereby reducing adhesion after PCT. In particular, lactone groups can have a longer length of consecutive carbon atoms than alkylene oxide groups, making them less hydrophilic and less susceptible to moisture penetration into the coating film, resulting in better adhesion to glass substrates after PCT testing.

The acrylic equivalent of the photopolymerizable compound is 90 g/eq or more and 400 g/eq or less, preferably 120 g/eq or more and 360 g/eq or less, more preferably 150 g/eq or more and 320 g/eq or less, and even more preferably 190 g/eq or more and 300 g/eq or less. When the acrylic equivalent of the photopolymerizable compound is 400 g/eq or less, the sensitivity to radiation (e.g., ultraviolet light) is high. Furthermore, the crosslink density is increased, which results in relatively large shrinkage of the coating film, allowing for a greater degree of light blocking per μm of cured film. In particular, the smaller the acrylic equivalent, the better the sensitivity. Furthermore, the molecular weight of the photopolymerizable compound is 200 to 5000, preferably 600 to 3500, more preferably 1000 to 1900, and even more preferably 1200 to 1900. By having a molecular weight of 5,000 or less, the photopolymerizable compound has good solubility in alkaline developer and moderate heat sagging properties, resulting in good pattern characteristics (e.g., pattern linearity) and a good cross-sectional shape.

The acrylic equivalent of a photopolymerizable compound can be determined, for example, by dividing the molecular weight by the number of acrylic functional groups. The weight-average molecular weight (Mw) of a photopolymerizable compound can be determined, for example, using the aforementioned gel permeation chromatography (GPC) "HLC-8220GPC."

The photopolymerizable compound, component (b) in this embodiment, preferably has a structure represented by the following general formula (1):

In formula (1), Y's are independently alkylene oxide groups having from 2 to 6 carbon atoms or groups having a structure in which a lactone having from 2 to 6 carbon atoms is ring-opened (-C(=O)-( _CH2 ) _k -O-), preferably alkylene oxide groups having from 2 to 6 carbon atoms or groups having a structure in which a lactone having from 4 to 6 carbon atoms is ring-opened, more preferably at least one of Y's is a group having a structure in which a lactone having from 6 carbon atoms is ring-opened, and even more preferably all of Y's are groups having a structure in which a lactone having from 6 carbon atoms is ring-opened. a to e' are independently integers from 0 to 6, with the proviso that at least one of a to e' is an integer from ₁ to 6. a to e' are preferably 1 or 2. _R1 to R5 _'s are independently preferably groups selected from the group consisting of (meth)acryloyl groups and hydroxy groups, and at least two of R1 to R5 _'s are (meth)acryloyl groups. It is preferable that R ₁ to R ₅ are all (meth)acryloyl groups. Z is preferably a group selected from the group consisting of substituted or unsubstituted monovalent to tetravalent hydrocarbon groups, -O-, and -S-, more preferably a group selected from the group consisting of substituted or unsubstituted divalent hydrocarbon groups, -O-, and -S-, and even more preferably -O-. 1 is independently 0 or 1, preferably 0. m is an integer of 1 to 4, the same as the valence of Z, preferably 2. k is an integer of 1 to 5, preferably 3 to 5. However, when component (b) contains multiple photopolymerizable compounds represented by general formula (1), the respective photopolymerizable compounds may be the same or different.

The photopolymerizable compound represented by the above general formula (1) has a large acrylic equivalent compared to a compound not having an alkylene oxide group or a group having a ring-opened lactone structure (e.g., DPHA), but has a long molecular chain and is a polyfunctional acrylate monomer, so that it has good sensitivity to exposure.
Furthermore, although the photopolymerizable compound has a relatively large molecular weight, it contains many hydrophilic functional groups such as esters and ethers in the molecule, and therefore has very good solubility in an alkaline developer, allowing for rapid pattern development.

In addition, because the photopolymerizable compound has a relatively large molecular weight, it is less likely to sag during post-baking, allowing for the formation of patterns with a good cross-sectional shape that maintains its rectangular shape. Furthermore, compared to compounds that do not have alkylene oxide groups or groups with a lactone ring-opening structure (e.g., DPHA), the photopolymerizable compound has a lower cross-linking density, resulting in less shrinkage during baking and allowing for a higher volume resistivity.

The photopolymerizable compound represented by the general formula (1) above preferably has 2 to 20 (meth)acryloyl groups, more preferably 3 to 10 (meth)acryloyl groups, and even more preferably 3 to 6 (meth)acryloyl groups. When the photopolymerizable compound has two or more (meth)acryloyl groups, the photopolymerizable compound has high sensitivity to radiation (e.g., ultraviolet light). Furthermore, when the number of (meth)acryloyl groups is 20 or less, good patterning characteristics (pattern line width, pattern straightness) are obtained.

Specific examples of photopolymerizable compounds represented by the above general formula (1) include ethylene oxide-modified dipentaerythritol hexaacrylate, dipentaerythritol dicaprolactone hexaacrylate, dipentaerythritol tricaprolactone hexaacrylate, dipentaerythritol hexacaprolactone hexaacrylate, dipentaerythritol polycaprolactone hexaacrylate (all manufactured by Nippon Kayaku Co., Ltd.), trimethylolpropane propylene oxide-modified triacrylate, and trimethylolpropane ethylene oxide-modified triacrylate (all manufactured by Toagosei Co., Ltd.). Among these, ethylene oxide-modified dipentaerythritol hexaacrylate, dipentaerythritol dicaprolactone hexaacrylate, dipentaerythritol tricaprolactone hexaacrylate, dipentaerythritol hexacaprolactone hexaacrylate, and dipentaerythritol polycaprolactone hexaacrylate are more preferred. The above photopolymerizable compounds may be used alone or in combination of two or more.

Component (b) may be a photopolymerizable compound other than the photopolymerizable compound represented by general formula (1) above. The photopolymerizable compound may be used in combination with the photopolymerizable compound represented by general formula (1) above, or may be used in place of the photopolymerizable compound represented by general formula (1) above.

Examples of photopolymerizable compounds other than the photopolymerizable compound represented by general formula (1) above include bisphenol F ethylene oxide-modified diacrylate, bisphenol A ethylene oxide-modified diacrylate, isocyanuric acid ethylene oxide-modified di- and triacrylate, diglycerin ethylene oxide-modified acrylate (all manufactured by Toagosei Co., Ltd.), and alkylene oxide-modified hexa(meth)acrylate of phosphazene.

[(b') Other Photopolymerizable Compounds]
The photosensitive resin composition of the present invention may contain, as (b') other photopolymerizable compounds, a photopolymerizable compound that does not have an alkylene oxide group or a group having a lactone ring-opened structure. By containing the (b') other photopolymerizable compounds, it is possible to adjust the sensitivity and crosslink density.

Examples of the above (b') other photopolymerizable compounds include (meth)acrylic acid esters having a hydroxyl group, such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate; ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, tetramethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, glycerol (meth)acrylate, glycerol di(meth)acrylate, Examples of photopolymerizable compounds include (meth)acrylic acid esters such as acrylate, glycerol tri(meth)acrylate, sorbitol penta(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and sorbitol hexa(meth)acrylate; urethane acrylate monomers such as pentaerythritol triacrylate toluene diisocyanate urethane prepolymer, pentaerythritol triacrylate hexamethylene isocyanate urethane prepolymer, pentaerythritol triacrylate isophorone diisocyanate urethane prepolymer, and dipentaerythritol pentaacrylate hexamethylene diisocyanate urethane prepolymer; and compounds having an ethylenic double bond such as dendritic polymers having a (meth)acrylic group. These other photopolymerizable compounds may be used alone or in combination of two or more.

The blending ratio of the above component (a) to the photopolymerizable compound (the sum of the above components (b) and (b')) is preferably 50/50 or more and 90/10 or less, more preferably 60/40 or more and 80/20 or less, and even more preferably 60/40 or more and 75/25 or less, in terms of the weight ratio (a)/((b) + (b')). When the blending ratio of the above component (a) is 50/50 or more, the hardness of the cured film after photocuring is sufficient. In addition, the acid value of the coating film is sufficiently high in the unexposed areas, resulting in good alkaline developability and enabling the formation of linear, sharp patterns in a short period of time. Furthermore, when the blending ratio of the above component (a) is 90/10 or less, the proportion of photoreactive functional groups in the resin is sufficient, enabling the formation of the desired crosslinked structure. Furthermore, because the acid value of the resin component is appropriate and the solubility in alkaline developer in the exposed areas is not excessively high, the formed pattern can be prevented from being thinner than the target line width or from being missing.

When the photopolymerizable compound contains (b) a photopolymerizable compound represented by general formula (1) and (b') another photopolymerizable compound, the blending ratio of component (b) to component (b') is preferably a weight ratio (b)/(b') of 15/85 or more and 100/0 or less, and more preferably 50/50 or more and 100/0 or less. By keeping it in this range, the above-mentioned effects of the photopolymerizable compound represented by general formula (1) can be fully obtained.

[(c) Component]
Component (c) is a photopolymerization initiator. By including component (c), the reaction in the area irradiated with radiation (e.g., ultraviolet light) proceeds sufficiently, and the solubility of the cured area during development is reduced, making it possible to form a desired fine pattern.

The photopolymerization initiator is not particularly limited, as long as it is a compound that has a polymerizable unsaturated bond and can initiate polymerization of an addition-polymerizable compound. Examples of photopolymerization initiators include acetophenone compounds, triazine compounds, benzoin compounds, benzophenone compounds, thioxanthone compounds, imidazole compounds, and oxime ester compounds. Note that, in the present invention, the term "photopolymerization initiator" is used to include sensitizers.

Examples of acetophenone compounds include acetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyl dimethyl ketal, 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]propan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-2-morpholino-1-(4-methylthiophenyl)propan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, and oligomers of 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propan-1-one.

Examples of triazine compounds include 2,4,6-tris(trichloromethyl)-1,3,5-triazine, 2-methyl-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-phenyl-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-chlorophenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, and 2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-1,3,5-triazine. )-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-methoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(3,4,5-trimethoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-methylthiostyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine, and 2-(pipronyl)-4,6-bis(trichloromethyl)-1,3,5-triazine.

Examples of benzoin compounds include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin tert-butyl ether, etc.

Examples of benzophenone compounds include benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3',4,4'-tetra(tert-butylperoxycarbonyl)benzophenone, 2,4,6-trimethylbenzophenone, and 4,4'-bis(N,N-diethylamino)benzophenone.

Examples of thioxanthone compounds include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, and the like.

Examples of imidazole compounds include 2-(o-chlorophenyl)-4,5-phenylimidazole dimer, 2-(o-chlorophenyl)-4,5-di(m-methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazole dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer, and 2,4,5-triarylimidazole dimer.

Examples of oxime ester compounds include 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-bicycloheptyl-1-one oxime-O-acetate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-adamantylmethan-1-one oxime-O-benzoate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-adamantylmethan-1-one oxime-O-acetate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-tetrahydrofuranylmethan-1-one oxime-O-benzoate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-tetrahydrofuranylmethan-1-one oxime- O-acetate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-thiophenylmethane-1-one oxime-O-benzoate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-thiophenylmethane-1-one oxime-O-acetate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole -3-yl]-morphonylmethane-1-one oxime-O-benzoate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-morphonylmethane-1-one oxime-O-acetate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-ethan-1-one oxime-O-bicycloheptanecarboxylate, 1-[ 9-Ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-ethan-1-one oxime-O-tricyclodecane carboxylate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-ethan-1-one oxime-O-adamantane carboxylate, 1-[4-(phenylsulfanyl)phenyl]octane-1,2-dione 2-o-benzoyl oxime, 1-[9-ethyl-6-(2-methylbenzoyl)carbazol-3-yl]ethanone-o-acetyl oxime, (2-methylphenyl)(7-nitro-9,9-dipropyl-9H-fluoren-2-yl)-acetyl oxime, ethanone, 1-[7-(2-methylbenzoyl)-9,9-dipropyl-9H-fluoren-2-yl]-1-(o-acetyl oxime) , ethanone, 1-(-9,9-dibutyl-7-nitro-9H-fluoren-2-yl)-1-o-acetyloxime, 1,2-octanedien, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime), 1-(4-phenylsulfanylphenyl) Examples of photopolymerization initiators include 1-(4-methylsulfanylphenyl)butane-1,2-dione-2-oxime-O-benzoate, 1-(4-methylsulfanylphenyl)butane-1,2-dione-2-oxime-O-acetate, 1-(4-methylsulfanylphenyl)butan-1-one oxime-O-acetate, 4-ethoxy-2-methylphenyl-9-ethyl-6-nitro-9H-carbazol-3-yl-O-acetyloxime, etc. One of the above photopolymerization initiators may be used alone, or two or more may be used in combination.

In particular, when preparing a photosensitive resin composition containing a high concentration of a light-blocking agent, it is preferable to use O-acyloxime compounds (including ketoximes). Specific examples of this compound group include O-acyloxime photopolymerization initiators represented by general formula (5) or general formula (6). Among these compounds, when using a light-blocking agent at a high pigment concentration or when forming a light-blocking film pattern, it is preferable to use an O-acyloxime photopolymerization initiator with a molar absorption coefficient at 365 nm of 10,000 L/mol cm or more.

In formula (5), R ₂₁ and R ₂₂ are each independently a C1 to C15 alkyl group, a C6 to C18 aryl group, a C7 to C20 arylalkyl group, or a C4 to C12 heterocyclic group, and R ₂₃ is a C1 to C15 alkyl group, a C6 to C18 aryl group, or a C7 to C20 arylalkyl group. Here, the alkyl group and aryl group may be substituted with a C1 to C10 alkyl group, a C1 to C10 alkoxy group, a C1 to C10 alkanoyl group, or a halogen, and the alkylene portion may contain an unsaturated bond, an ether bond, a thioether bond, or an ester bond. The alkyl group may be linear, branched, or cyclic.

In formula (6), R ₂₄ and R ₂₅ each independently represent a linear or branched alkyl group having 1 to 10 carbon atoms, a cycloalkyl group, cycloalkylalkyl group, or alkylcycloalkyl group having 4 to 10 carbon atoms, or a phenyl group which may be substituted with an alkyl group having 1 to 6 carbon atoms. R ₂₆ independently represents a linear or branched alkyl group or alkenyl group having 2 to 10 carbon atoms, and some of the —CH ₂ — groups in the alkyl group or alkenyl group may be substituted with —O— groups. Furthermore, some of the hydrogen atoms in these groups R ₂₄ to R ₂₆ may be substituted with halogen atoms.

Component (c) may be an active radical generator or an acid generator.

Examples of active radical generators include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,2'-bis(o-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 10-butyl-2-chloroacridone, 2-ethylanthraquinone, benzil, 9,10-phenanthrenequinone, camphorquinone, methyl phenylglyoxylate, and titanocene compounds.

Examples of acid generators include onium salts such as 4-hydroxyphenyldimethylsulfonium p-toluenesulfonate, 4-hydroxyphenyldimethylsulfonium hexafluoroantimonate, 4-acetoxyphenyldimethylsulfonium p-toluenesulfonate, 4-acetoxyphenylmethylbenzylsulfonium hexafluoroantimonate, triphenylsulfonium p-toluenesulfonate, triphenylsulfonium hexafluoroantimonate, diphenyliodonium p-toluenesulfonate, and diphenyliodonium hexafluoroantimonate, as well as nitrobenzyl tosylates and benzoin tosylates.

Additionally, compounds that do not function as photopolymerization initiators or sensitizers by themselves but can enhance the photopolymerization initiator or sensitizer capabilities when used in combination with the above-mentioned compounds may be added. Examples of such compounds include amine compounds that are effective when used in combination with benzophenone. Examples of the above amine compounds include triethylamine, triethanolamine, methyldiethanolamine, triisopropanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 2-dimethylaminoethyl benzoate, 2-ethylhexyl 4-dimethylaminobenzoate, N,N-dimethyl-p-toluidine, 4,4'-bis(dimethylamino)benzophenone, 4,4'-bis(diethylamino)benzophenone, and 4,4'-bis(ethylmethylamino)benzophenone.

The content of component (c) is preferably 3 to 30 parts by weight, and more preferably 4 to 10 parts by weight, relative to 100 parts by weight of the total of component (a) and components ((b) + (b')). When the content of component (c) is 3 parts by weight or more, a moderate photopolymerization speed is achieved, ensuring sufficient sensitivity. Furthermore, when the content of component (c) is 30 parts by weight or less, line widths faithful to the mask can be reproduced and pattern edges can be sharpened.

[(d) Component]
The component (d) is a light-blocking agent. By including the component (d), the light-blocking properties of the color filter can be sufficiently obtained.

In this embodiment, black pigments and mixed-color organic pigments can be used as the light-blocking agent (component (d)).

Examples of black pigments include perylene black, cyanine black, aniline black, lactam black, carbon black, titanium black, chromium oxide, iron oxide, etc.

Examples of mixed-color organic pigments include those that are pseudo-black by mixing at least two colors selected from organic pigments such as azo pigments, condensed azo pigments, azomethine pigments, phthalocyanine pigments, quinacridone pigments, isoindolinone pigments, isoindoline pigments, dioxazine pigments, threne pigments, perylene pigments, perinone pigments, quinophthalone pigments, diketopyrrolopyrrole pigments, and thioindigo pigments.

The above component (d) may be used alone or in combination with two or more types, depending on the desired function of the photosensitive resin composition.

Examples of organic pigments that can be used when a mixed color organic pigment is used as component (d) include, but are not limited to, those having the following color index numbers:
Pigment Red 2, 3, 4, 5, 9, 12, 14, 22, 23, 31, 38, 112, 122, 144, 146, 147, 149, 166, 168, 170, 175, 176, 177, 178, 179, 184, 185, 187, 188, 202, 207, 208, 209, 210, 213, 214, 220, 221, 242, 247, 253, 254, 255, 256, 257, 262, 264, 266, 272, 279, etc. Pigment Orange 5, 13, 16, 34, 36, 38, 43, 61, 62, 64, 67, 68, 71, 72, 73, 74, 81, etc. Pigment Yellow 1, 3, 12, 13, 14, 16, 17, 55, 73, 74, 81, 83, 93, 95, 97, 109, 110, 111, 117, 120, 126, 127, 128, 129, 130, 136, 138, 139, 150, 151, 153, 154, 155, 173, 174, 175, 176, 180, 181, 183, 185, 191, 194, 199, 213, 214, etc. Pigment Green 7, 36, 58, etc. Pigment Blue 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 60, 80, etc. Pigment Violet 19, 23, 37, etc.

Among the above light-blocking agents, carbon black, a black pigment, is preferred due to its excellent light-blocking properties, surface smoothness, dispersion stability, and compatibility with resins.

The blending ratio of component (d) can be determined arbitrarily depending on the desired light-blocking degree, but is preferably 30% by mass or more and 60% by mass or less, more preferably 40% by mass or more and 60% by mass or less, and even more preferably 45% by mass or more and 60% by mass or less, based on the solid content of the photosensitive resin composition. When the light-blocking agent is 30% by mass or more based on the solid content of the photosensitive resin composition, sufficient light-blocking properties can be obtained. When the light-blocking agent is 60% by mass or less, a sufficient amount of photosensitive resin is contained, thereby achieving the desired development characteristics and film-forming ability.

The above-mentioned component (d) is usually mixed with other formulation components as a light-blocking component dispersion dispersed in a dispersion medium, and a dispersant can be added in this case. The dispersant can be any known compound used to disperse pigments (light-blocking components) (compounds commercially available under the names of dispersants, dispersing wetting agents, dispersion promoters, etc.), and can be used without particular limitation.

Examples of dispersion media include propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, etc.

Examples of dispersants include cationic polymer dispersants, anionic polymer dispersants, nonionic polymer dispersants, and pigment derivative dispersants (dispersing aids). In particular, the dispersant is preferably a cationic polymer dispersant that has a cationic functional group, such as an imidazolyl group, pyrrolyl group, pyridyl group, or primary, secondary, or tertiary amino group, as an adsorption site for the colorant, an amine value of 1 mgKOH/g to 100 mgKOH/g, and a number-average molecular weight (Mn) of 1,000 to 100,000. The blending amount of this dispersant is preferably 1% to 35% by weight, and more preferably 2% to 25% by weight, of the light-blocking component. High-viscosity substances such as resins generally have the effect of stabilizing dispersion, but those without dispersion-promoting properties are not considered dispersants. However, this does not limit their use for the purpose of stabilizing dispersion.

[(e) Component]
Component (e) is a solvent. By including component (e), a liquid photosensitive resin composition containing the above-mentioned components (a) to (d) can be obtained.

Examples of component (e) include alcohols such as methanol, ethanol, n-propanol, isopropanol, ethylene glycol, and propylene glycol; terpenes such as α- or β-terpineol; ketones such as acetone, methyl ethyl ketone, cyclohexanone, and N-methyl-2-pyrrolidone; aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene; methyl cellosolve, ethyl cellosolve, methyl carbitol, ethyl carbitol, butyl carbitol, propylene glycol monomethyl ether, and propylene glycol monoethyl ether. Examples of the (e) component include glycol ethers such as dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monomethyl ether, and triethylene glycol monoethyl ether, and acetate esters such as ethyl acetate, butyl acetate, cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, carbitol acetate, ethyl carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate. Component (e) may be used alone or in combination of two or more types.

The content of component (e) varies depending on the target viscosity, but is preferably 70% by mass or more and 90% by mass or less relative to the total mass of the photosensitive resin composition. When the content of component (e) is 70% by mass or more, the viscosity can be made such that the photosensitive resin composition can be easily applied to a substrate, and when the content is 90% by mass or less, the time required for drying after applying the photosensitive resin composition to a substrate can be shortened.

[Surfactant]
The photosensitive resin composition for black resist according to the present invention may contain a surfactant from the viewpoint of smoothness of the light-shielding film and suppression of Benard cell.

Examples of surfactants include anionic surfactants such as ammonium lauryl sulfate and polyoxyethylene alkyl ether triethanolamine sulfate; cationic surfactants such as stearylamine acetate and lauryl trimethylammonium chloride; amphoteric surfactants such as lauryl dimethylamine oxide and lauryl carboxymethyl hydroxyethyl imidazolinium betaine; nonionic surfactants such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether and sorbitan monostearate; silicone-based surfactants with a polydimethylsiloxane or similar main skeleton; and fluorine-based surfactants. The above surfactants may be used alone or in combination of two or more.

The surfactant content is preferably 0.001% by mass or more and 5% by mass or less, and more preferably 0.01% by mass or more and 1% by mass or less, based on the total mass of the solids. When the surfactant content is 0.001% by mass or more, based on the total mass of component (a), the desired smoothness of the light-shielding film can be achieved and Benard cells can be suppressed. When it is 5% by mass or less, good coating film properties can be obtained.

[Coupling Agent]
The photosensitive resin composition for black resist according to the present invention may contain a silane coupling agent from the viewpoint of improving adhesion between the glass surface and the cured film through chemical bonding.

Preferred silane coupling agents have a reactive group such as an amino group, an isocyanate group, a ureido group, an epoxy group, a vinyl group, a (meth)acrylic group, or a mercapto group, and more preferred are those having an epoxy group, an isocyanate group, or a methacryl group. Specific examples of the above coupling agents include 3-(glycidyloxy)propyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, and 3-ureidopropyltriethoxysilane.

The content of the silane coupling agent is preferably 0.3% by mass or more and 2% by mass or less, and more preferably 0.7% by mass or more and 1.4% by mass or less, based on the solid content of the photosensitive resin composition. When the content of the silane coupling agent is 0.3% by mass or more, sufficient adhesion can be obtained between the glass substrate and the cured film. When the content of the silane coupling agent is 2% by mass or less, the generation of aggregated foreign matter can be suppressed.

[Other ingredients]
The photosensitive resin composition for black resist according to the present invention may contain additives such as other resin components, curing agents, curing accelerators, thermal polymerization inhibitors and antioxidants, plasticizers, fillers, leveling agents, antifoaming agents, viscosity modifiers, and ultraviolet absorbers, as required.

Examples of other resin components include vinyl resin, polyester resin, polyamide resin, polyimide resin, polyurethane resin, polyether resin, melamine resin, epoxy resin, etc.

Examples of epoxy resins include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol fluorene type epoxy compounds, bisnaphthol fluorene type epoxy compounds, diphenyl fluorene type epoxy compounds, phenol novolac type epoxy compounds, cresol novolac type epoxy compounds, phenol aralkyl type epoxy compounds, phenol novolac compounds containing a naphthalene skeleton (e.g., NC-7000L, manufactured by Nippon Kayaku Co., Ltd.), biphenyl type epoxy compounds (e.g., jERYX4000, manufactured by Mitsubishi Chemical Corporation; "jER" is a registered trademark of the company), naphthol aralkyl type epoxy compounds, trisphenol methane type epoxy compounds (e.g., EPPN-501H, manufactured by Nippon Kayaku Co., Ltd.), tetrakisphenol ethane type epoxy compounds, glycidyl ethers of polyhydric alcohols, ethers, glycidyl esters of polycarboxylic acids, copolymers of monomers having a (meth)acryloyl group containing glycidyl (meth)acrylate as a unit, such as copolymers of methacrylic acid and glycidyl methacrylate; epoxy compounds having a glycidyl group, such as hydrogenated bisphenol A diglycidyl ether (for example, Rikaresin HBE-100, manufactured by New Japan Chemical Co., Ltd., "Rikaresin" is a registered trademark of the company); 1,4-cyclohexanedimethanol-bis-3,4-epoxycyclohexanecarboxylate, 2-(3,4-epoxy)cyclohexyl-5,1-spiro(3,4-epoxy)cyclohexyl-m-dioxane (for example, Araldite CY175, manufactured by Huntsman, "Araldite" is a registered trademark of the company); bis(3,4-epoxycyclohexylmethyl)adipate (for example, CYRACURE UVR-6128: manufactured by Dow Chemical Company), 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (e.g., Celloxide 2021P: manufactured by Daicel Corporation, "Celloxide" is a registered trademark of the company), butanetetracarboxylic acid tetra(3,4-epoxycyclohexylmethyl)-modified ε-caprolactone (e.g., Epolead GT401: manufactured by Daicel Corporation, "Epolead" is a registered trademark of the company), epoxy compounds having an epoxycyclohexyl group (e.g., HiREM-1: manufactured by Shikoku Chemical Industry Co., Ltd.), These include polyfunctional epoxy compounds having a dicyclopentadiene skeleton (e.g., HP7200 series: manufactured by DIC Corporation), alicyclic epoxy compounds such as 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol (e.g., EHPE3150: manufactured by Daicel Corporation), epoxidized polybutadiene (e.g., NISSO-PB JP-100: manufactured by Nippon Soda Co., Ltd., "NISSO-PB" is a registered trademark of the company), and epoxy compounds having a silicone skeleton.

Examples of curing agents include amine compounds, polycarboxylic acid compounds, phenolic resins, amino resins, dicyandiamide, Lewis acid complex compounds, etc., which contribute to the curing of epoxy resins.

Examples of curing accelerators include tertiary amines, quaternary ammonium salts, tertiary phosphines, quaternary phosphonium salts, borate esters, Lewis acids, organometallic compounds, imidazoles, etc., which contribute to accelerating the curing of epoxy resins.

Examples of thermal polymerization inhibitors and antioxidants include hydroquinone, hydroquinone monomethyl ether, pyrogallol, tert-butylcatechol, phenothiazine, hindered phenol compounds, etc.

Examples of plasticizers include dibutyl phthalate, dioctyl phthalate, tricresyl phosphate, etc. Examples of fillers include glass fiber, silica, mica, alumina, etc.

Examples of leveling agents and defoaming agents include silicone-based, fluorine-based, and acrylic compounds.

The photosensitive resin composition for black resist of the present invention can be obtained by mixing the above-mentioned components (a) to (e) and optional component (b').

The photosensitive resin composition for black matrices of the present invention preferably contains the above components (a) to (d) and optional component (b') in a total amount of 80% by mass or more, and more preferably 90% by mass or more, of the solids excluding the solvent (the solids include monomers that become solids after curing).

The photosensitive resin composition for black resist of the present invention has good adhesion to glass substrates even after PCT, high exposure sensitivity, and is capable of forming a light-shielding film with excellent pattern linearity, volume resistivity, and light-shielding ability, as well as a good cross-sectional shape.

2. Manufacturing Method of Light-Shielding Film for Color Filter The manufacturing method of the light-shielding film for color filter will be described below.

The method for producing a color filter light-shielding film according to the present invention comprises: (1) a coating film formation step in which the above-described photosensitive resin composition for black resist is applied to a transparent substrate and dried to form a coating film of the above-described photosensitive resin composition for black resist; (2) an exposure step in which part of the coating film is irradiated with radiation through a photomask; (3) a development step in which the irradiated coating film is developed to remove the unexposed portions; and (4) a heat curing step in which the developed coating film is heat cured. Each step is described below.

[Coating film formation process]
The coating film forming step is a step of applying the above-mentioned photosensitive resin composition for black resist onto a substrate and drying it to form a coating film.

The substrate may be any known substrate. Examples of substrates include glass substrates, silicon wafers, and plastic substrates (e.g., polyethylene terephthalate, polybutylene terephthalate, polyethersulfone, polycarbonate, polyimide, etc.) on which transparent electrodes such as ITO or gold are vapor-deposited or patterned.

The photosensitive resin composition can be applied using known coating methods. Examples of such coating methods include known solution immersion methods, spraying methods, and methods using roller coaters, land coaters, slit coaters, and spinners. These methods allow the photosensitive resin composition to be applied to the desired thickness.

The photosensitive resin composition applied by the above method can be dried using known drying methods. The drying method can be carried out by heating using an oven, hot air blower, hot plate, infrared heater, etc., vacuum drying, or a combination of these. The heating temperature and heating time for the resin film can be selected appropriately depending on the solvent used. The heating temperature and heating time can be selected appropriately depending on the solvent used, and are preferably carried out at 60 to 110°C for 1 to 5 minutes, for example.

[Exposure process]
The exposure step is a step in which a part of the coating layer is irradiated with radiation through a photomask to photocure the part of the coating (photosensitive resin composition) corresponding to the pattern.

A publicly known photomask can be used. Examples of photomasks include multi-tone masks such as half-tone masks and gray-tone masks. A gray-tone mask has a light-shielding portion and a diffraction grating formed on a light-transmitting substrate. The diffraction grating has light-transmitting regions such as slits, dots, and meshes spaced at intervals below the resolution limit of the light used for exposure, and this configuration controls the light transmittance. A half-tone mask has a light-shielding portion and a semi-transmitting portion formed on a light-transmitting substrate. The semi-transmitting portion controls the transmittance of the light used for exposure.

In the exposure step, the exposure apparatus and exposure conditions can be selected appropriately. Examples of the radiation to be irradiated include visible light, ultraviolet light, far ultraviolet light, electron beams, and X-rays. Among the above-mentioned radiation, ultraviolet light is preferred. Furthermore, known exposure apparatuses (ultra-high pressure mercury lamps, high pressure mercury lamps, metal halide lamps, far ultraviolet lamps, etc.) can be used as the radiation irradiator. Furthermore, the wavelength of the irradiated radiation is preferably 250 nm or more and 400 nm or less. The radiation exposure dose is preferably 25 mJ/ ^cm2 or more and 3000 mJ/ ^cm2 or less.

[Development process]
The development step is a step in which the irradiated coating film is developed with an alkali to remove the unexposed areas of the coating film.

Examples of coating development methods include shower development, spray development, dip (immersion) development, and puddle (puddle) development. The above development methods can be carried out using commercially available developing machines, ultrasonic cleaners, etc.

Examples of developers suitable for development include aqueous solutions of alkali metal or alkaline earth metal carbonates, and aqueous solutions of alkali metal hydroxides. Among these, it is preferable to use a weakly alkaline aqueous solution containing 0.05 to 3% by mass of a carbonate such as sodium carbonate, potassium carbonate, or lithium carbonate at a temperature of 23 to 28°C. Commercially available developing machines, ultrasonic cleaners, etc. can be used in the development process.

[Heat curing process]
The heat curing step is a step in which the exposed area (coating film) after development is heat treated to completely cure (post-bake).

The exposed area (coating film) after development can be heated by any known method (heating using an oven, hot air blower, hot plate, infrared heater, etc., vacuum drying, or a combination of these). There are no particular restrictions on the heating temperature, as long as it is a temperature at which the coating film undergoes full curing (post-baking). It is preferable to heat the film at a temperature of 180 to 250°C for 20 to 60 minutes.

The method for producing a light-shielding film for a color filter of the present invention uses the photosensitive resin composition for black resist of the present invention, which has good developability, thereby shortening the time required for the development process.

3. Light-shielding film The light-shielding film of the present invention is obtained by curing the above-mentioned photosensitive resin composition for black matrix. The light-shielding film of the present invention enables high light-shielding of liquid crystal panels. It can also be applied to liquid crystal displays with narrow frames.

The following describes in detail the embodiments of the present invention based on examples and comparative examples, but the present invention is not limited to these.

First, we will explain the synthesis examples of the alkali-soluble resin, which is component (a) of the present invention. Unless otherwise specified, the resins in the synthesis examples were evaluated as follows:

When the same model of measuring equipment is used, the name of the equipment manufacturer is omitted from the second line. In the examples, all glass substrates used to prepare the cured film-coated substrates for measurement are subjected to the same treatment. When the first decimal place of the content of each component is 0, the decimal point may be omitted.

[Solid content concentration]
The solid content concentration was calculated from the following formula using the weight [W ₁ (g)] of 1 g of the resin solution obtained in the synthesis example impregnated into a glass filter [weight: W ₀ (g)] and the weight [W ₂ (g)] after heating at 160°C for 2 hours.
Solid content concentration (wt%) = 100 x (W ₂ - W ₀ )/(W ₁ - W ₀ )

[Acid value]
The acid value was determined by dissolving the resin solution in dioxane and titrating it with a 1/10N aqueous KOH solution using a potentiometric titrator "COM-1600" (manufactured by Hiranuma Sangyo Co., Ltd.).

[Molecular weight]
The molecular weight was measured using gel permeation chromatography (GPC) "HLC-8220GPC" (manufactured by Tosoh Corporation, solvent: tetrahydrofuran, columns: TSKgelSuper H-2000 (2 columns) + TSKgelSuper H-3000 (1 column) + TSKgelSuper H-4000 (1 column) + TSKgelSuper H-5000 (1 column) (manufactured by Tosoh Corporation), temperature: 40°C, rate: 0.6 ml/min), and the weight average molecular weight (Mw) was calculated as a value converted into standard polystyrene (manufactured by Tosoh Corporation, PS-oligomer kit).

[Acrylic equivalent]
The acrylic equivalent weight was determined by dividing the molecular weight by the number of acrylic functional groups.

The abbreviations used in the synthesis examples are as follows.
BPFE: bisphenol fluorene type epoxy resin (an epoxy compound in which W in the compound of general formula (2) is a fluorene-9,9-diyl group, _R6 and _R7 are hydrogen, and n is 0 to 0.15)
AA: Acrylic acid BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride THPA: 1,2,3,6-tetrahydrophthalic anhydride TEAB: Tetraethylammonium bromide PGMEA: Propylene glycol monomethyl ether acetate

[Synthesis Example 1]
In a 500 mL four-neck flask equipped with a reflux condenser, BPFE (114.4 g, 0.23 mol), AA (33.2 g, 0.46 mol), PGMEA (157 g) and TEAB (0.48 g) were charged and stirred at 100 to 105 ° C. for 20 hours to react. Next, BPDA (35.3 g, 0.12 mol) and THPA (18.3 g, 0.12 mol) were charged into the flask and stirred at 120 to 125 ° C. for 6 hours to obtain an alkali-soluble resin solution (a). The solids concentration of the resin solution was 56.5 mass%, the acid value (solids equivalent) was 103 mg KOH / g, and the Mw by GPC analysis was 3600.

[Synthesis Example 2]
(Other photopolymerizable compounds)
PTMA (20 g, 0.19 mol of mercapto groups)), DPHA (212 g (2.12 mol of acrylic groups)), PGMEA (58 g), HQ (0.1 g), and BzDMA (0.01 g) were placed in a 1 L four-neck flask and reacted at 60°C for 12 hours to obtain dendritic polymer solution (b')-2. The solids concentration of the dendritic polymer solution was 80% by mass, and the Mw determined by GPC analysis was 10,000. The disappearance of the mercapto groups from the resulting dendritic polymer was confirmed by iodometry.

The photosensitive resin compositions for black resists in Examples 1 to 9 and Comparative Examples 1 and 2 were prepared using the blending amounts (unit: mass%) shown in Table 1. The blending components used in Table 1 are as follows. Note that the blending amounts of (a) to (d), (b') and dispersant in Table 1 represent the amount of solids only.

(alkali-soluble resin)
(a): Resin obtained in Synthesis Example 1 above

(Photopolymerizable compound)
(b)-1: Ethylene oxide-modified dipentaerythritol hexaacrylate (KAYARAD DPEA-12, acrylic equivalent 185 g/eq, molecular weight 1107)
(b)-2: Dipentaerythritol hexacaprolactone hexaacrylate (KAYARAD DPCA-60, acrylic equivalent 211 g/eq, molecular weight 1263)
(b)-3: Dipentaerythritol polycaprolactone hexaacrylate (KAYARAD DPCA-120, acrylic equivalent 325 g/eq, molecular weight 1948)

The photopolymerizable compounds (b)-1 to -3 are all manufactured by Nippon Kayaku Co., Ltd., and "KAYARAD" is a registered trademark of the same company.

(Other photopolymerizable compounds)
(b')-1: Dipentaerythritol penta/hexaacrylate mixture (KAYARAD DPHA, acrylic equivalent 97 g/eq, molecular weight 578, manufactured by Nippon Kayaku Co., Ltd., "KAYARAD" is a registered trademark of the company)
(b')-2: Resinous polymer obtained in Synthesis Example 2 above

(Photopolymerization initiator)
(c): Irgacure OXE02 (manufactured by BASF Japan Ltd., "Irgacure" is a registered trademark of the company)

(Light-blocking component)
(d): Carbon black and polymer dispersant

(solvent)
(e)-1: Propylene glycol monomethyl ether acetate (e)-2: Diethylene glycol dimethyl ether (e)-3: Diethylene glycol ethyl methyl ether

[evaluation]
(Preparation of substrate with cured film (coating film) for adhesion strength evaluation)
The photosensitive resin compositions for black resist shown in Table 1 were applied to a 125 mm x 125 mm glass substrate "#1737" (manufactured by Corning Incorporated) (hereinafter referred to as "glass substrate") using a spin coater so that the film thickness after heat curing would be 1.1 μm, and the coating was prebaked at 90°C for 1 minute using a hot plate to produce a hardened film (coating). Next, without using a negative photomask, the coating was irradiated with ultraviolet light at 100 mJ/ ^cm2 from an ultra-high pressure mercury lamp with an i-line illuminance of 30 mW/ ^cm2 to cause a photocuring reaction. The exposed cured film (coating) was then post-cured (post-baked) for 30 minutes using a hot air dryer at 230°C to obtain a substrate with a cured film (coating) for adhesion strength evaluation.

[Adhesion strength (sealing strength) evaluation]
(Evaluation method)
The test was carried out in accordance with the three-point bending adhesion test method of JIS K6856-1994.

Specifically, the substrate with the cured film (coating) and a glass substrate not coated with the photosensitive resin composition shown in Table 1 (hereinafter also referred to as the "uncoated substrate") were each cut into 20 mm x 63 mm strips to prepare test specimens. The substrate with the cured film (coating) and the uncoated substrate were then overlapped with a certain amount of sealant between them, and the two substrates (test specimens) were bonded together to a width of 8 mm. The overlapping sealant had a circular shape with a diameter of approximately 5 mm. The overlapping test specimens were then prebaked at 90°C for 20 minutes, followed by postbaking at 150°C for 2 hours to prepare three-point bending test specimens. A pressure cooker test (PCT) was then performed at 100% RH, 2 atm, and 121°C for 5 hours.

The three-point bending test is performed as follows: The test piece obtained above is supported by two supports (the distance between the two supports is 3 cm) so that the overlapping portion is at the center, and a load is applied from directly above the overlapping portion to directly below using a tensile tester "Tensilon UCT-100" (manufactured by Orientec Co., Ltd.) at a rate of 1 mm/min. The peeled surface is observed and the load at that time is read. This value is divided by the area of the applied sealant to determine the load per unit area as the adhesion strength.

(Evaluation criteria)
◎: Adhesion strength after PCT is 30 kgf/cm ² or more. ○: Adhesion strength after PCT is 10 kgf/cm ² or more and less than 30 kgf/cm ^2. ×: Adhesion strength after PCT is less than 10 kgf/cm ^2.

(Preparation of substrates with cured films (coating films) for evaluating pattern line width, pattern linearity, and taper angle)
The photosensitive resin composition for black resist shown in Table 1 was applied to a 125 mm × 125 mm glass substrate using a spin coater so that the film thickness after heat curing would be 1.1 μm, and the substrate was prebaked for 1 minute at 90° C. Thereafter, the exposure gap was adjusted to 100 μm, a 10 μm striped negative photomask was placed over the dried coating, and ultraviolet light of 100 mJ/cm ² was irradiated from an ultra-high pressure mercury lamp (wavelength 365 nm, i-line illuminance 30 mW/cm ² ) to cause a photocuring reaction (exposure) of the photosensitive portion.

Next, the exposed cured film (coating film) was developed in a 0.05% aqueous potassium hydroxide solution at 23°C under a shower pressure of ¹ kgf/cm2 for a period of dissolution time plus 20 seconds, and then washed with water sprayed at 5 kgf/ ^cm2. The developed cured film (coating film) was post-cured (post-baked) using a hot air dryer at 230°C for 30 minutes to obtain a substrate with a cured film (coating film) for evaluation of pattern line width, pattern linearity, and taper angle.

[Dissolution time]
(Evaluation method)
The development was carried out under the above conditions while checking the state of the developed substrate, and the film dissolution time [s] was measured. The time when the glass substrate in the unexposed part of the black film was exposed was taken as the dissolution time.

(Evaluation criteria)
◯: Dissolution time is less than 25 seconds. △: Dissolution time is 25 seconds or more and less than 40 seconds. ×: Dissolution time is 40 seconds or more.

[Pattern line width evaluation]
(Evaluation method)
After main curing (post-baking), the pattern line width [μm] of a mask width of 10 μm was measured using a length measuring microscope "XD-20" (manufactured by Nikon Corporation).

(Evaluation criteria)
◯: The pattern line width is 10 μm or more. △: The pattern line width is 8 μm or more and less than 10 μm. ×: The pattern line width is less than 8 μm.

[Pattern linearity evaluation]
(Evaluation method)
The 10 μm mask pattern after main curing (post-baking) was observed using an optical microscope.

(Evaluation criteria)
◯: No jaggedness is observed at the edge of the pattern △: Slight jaggedness is observed at the edge of the pattern ×: Jaggedness is observed at the edge of the pattern

[Taper angle]
(Evaluation method)
The taper angle [°] of a mask width of 10 μm was measured using a scanning electron microscope (SEM) "VE-7800" (manufactured by Keyence Corporation).

(Evaluation criteria)
◯: The taper angle is 55° or more. △: The taper angle is 30° or more and less than 55°. ×: The taper angle is less than 30°.

[Volume resistivity]
(Evaluation method)
The photosensitive resin composition for black resist was applied to a 100 mm x 100 mm chrome-deposited substrate (manufactured by Technoprint Co., Ltd.) using a spin coater so that the film thickness after post-baking would be 3.0 μm, and the coating was pre-baked at 90°C for 1 minute. The coating was then subjected to a solid exposure at 100 mJ/ ^cm2 without using a negative photomask, and post-baked at 230°C for 180 minutes using a hot air dryer. Aluminum terminals were attached to the post-baked substrate, and the volume resistivity [Ω cm] of the cured film (coating film) was measured using a volume resistivity meter "6517A" (manufactured by Keithley Instruments Co., Ltd.).

(Evaluation criteria)
○: The volume resistivity is 12 or more (1.0×10^12 Ω·cm) when an applied voltage of 10 V is used. ×: The volume resistivity is less than 12 (1.0×10^12 Ω·cm) when an applied voltage of 10 V is used.

The above evaluation results are shown in Table 2.

The light-shielding films (coatings) obtained from the photosensitive resin compositions of Examples 1 to 9 showed favorable results in the evaluation of adhesion strength after PCT. In particular, the photosensitive resin compositions of Examples 2 to 9, which contained photopolymerizable compounds with lactone groups, showed extremely favorable results in the evaluation of adhesion strength. The reason for the improved adhesion is thought to be that, as mentioned above, ethylene oxide groups and lactone groups contain single-bonded oxygen atoms, which impart flexibility to the coating film and alleviate the internal stress of the coating film that occurs during thermal curing shrinkage. Furthermore, lactone groups can have a longer length of consecutive carbon atoms than alkylene oxide groups, which is thought to make them less hydrophilic and less likely to allow moisture to penetrate into the coating film.

The photosensitive resin compositions of Examples 1 to 9 also achieved favorable results in terms of pattern linearity, dissolution time, taper angle, and volume resistivity. The improved pattern linearity is believed to be due to the fact that, although the acrylic equivalent of the photopolymerizable compound (component (b)) is higher than that of compounds without alkylene oxide or lactone groups, it has a long molecular chain and is a polyfunctional acrylate monomer, resulting in high sensitivity to light exposure. The improved dissolution time is believed to be due to the fact that, despite the relatively high molecular weight of the photopolymerizable compound, it contains many hydrophilic functional groups such as esters and ethers, thereby improving solubility in alkaline developers. The increased taper angle is believed to be due to the fact that the photopolymerizable compound's relatively high molecular weight makes it less susceptible to thermal sagging during post-baking. The improved volume resistivity is believed to be due to the fact that, compared to photopolymerizable compounds without alkylene oxide or lactone groups, it has a lower crosslink density, resulting in less shrinkage during baking.

When liquid crystal panels were produced using color filters with black matrices formed using the photosensitive resin compositions of Examples 1 to 9 above, there was almost no peeling of the black matrix, even under harsh conditions, and liquid crystal leakage was prevented. Furthermore, a light-shielding film with a high taper angle was obtained by curing the photosensitive resin composition above without sacrificing pattern characteristics (pattern linearity, etc.). Furthermore, during manufacturing, the positive effect of shortening development time was achieved. Therefore, even when producing black matrices with high light-shielding rates or narrow adhesive areas, peeling of the coating film from the glass substrate is reduced, ensuring high productivity (yield) and reliability.

The photosensitive resin composition for black resist of the present invention can provide a photosensitive resin composition for black resist that has high adhesion to glass substrates even after PCT, high exposure sensitivity, excellent pattern linearity, volume resistivity, and light-shielding degree, and is capable of forming a light-shielding film with a good cross-sectional shape. Furthermore, use of the photosensitive resin composition for black resist of the present invention can shorten the time required for the development process. The photosensitive resin composition for black resist of the present invention can obtain the necessary adhesion strength even with a small adhesion area, making it possible to reduce the frame area of displays. This contributes to the design and miniaturization of devices.

Claims (3)

(a) an alkali-soluble resin;
(b) dipentaerythritol hexacaprolactone hexaacrylate; and
(c) a photopolymerization initiator containing an oxime ester compound ;
(d) a light-blocking agent; and
(e) a solvent;
a photosensitive resin composition for black resist, which is applied to a transparent substrate, dried on the transparent substrate, and then exposed to light on the same transparent substrate to be cured, thereby forming a cured product that is in close contact with the transparent substrate ,
The component (a) is a polymerizable unsaturated group-containing alkali-soluble resin obtained by further reacting a reaction product of a bisphenol-type epoxy compound represented by the following general formula (2) with (meth)acrylic acid with a polybasic carboxylic acid or an anhydride thereof:
(In formula (2), R ₆ and R ₇ independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 5 carbon atoms, or a halogen atom; W represents —CO—, —SO ₂ —, —C(CF ₃ ) ₂ —, —Si(CH ₃ ) ₂ —, —CH ₂ —, —C(CH ₃ ) ₂ —, —O—, a fluorene-9,9-diyl group represented by the following general formula (3), or a single bond, with the proviso that at least one of W is a fluorene-9,9-diyl group represented by the general formula (3), and n is an integer of 0 to 10.)
Photosensitive resin composition for black resist. A light-shielding film obtained by curing the photosensitive resin composition for black resist according to claim 1 . a coating film forming step of applying the photosensitive resin composition for black resist according to claim 1 onto a transparent substrate and drying the applied composition to form a coating film of the photosensitive resin composition for black resist;
an exposure step of irradiating a portion of the coating film on the transparent substrate with radiation through a photomask;
a developing step of developing the radiation-irradiated coating film on the transparent substrate to remove unexposed portions;
a heat curing step of heat curing the developed coating film on the transparent substrate ;
and forming a cured product in close contact with the transparent substrate .