JP7705745B2 - Photosensitive resin composition for black resist, its manufacturing method, light-shielding film, color filter, touch panel and display device - Google Patents

Description

The present invention relates to a photosensitive resin composition for black resist, a method for producing the photosensitive resin composition, a light-shielding film obtained by curing the composition, a color filter and a touch panel having the light-shielding film, and a display device having the color filter or touch panel.

In recent years, with the development of mobile terminals, there has been an increase in display devices with touch panels or liquid crystal panels for use outdoors or in vehicles. In such display devices, the outer frame of the touch panel is provided with a light-shielding film to block light leakage from the periphery of the liquid crystal panel on the back, and the liquid crystal panel is provided with a light-shielding film (black matrix) to prevent light leakage from the screen when displaying black and to prevent color mixing between adjacent color resists.

In display devices, etc., in order to suppress light leakage and improve the visibility of the screen of the display device, etc., the concentration of black pigment in the light-shielding film may be increased to increase the light-shielding properties of the light-shielding film (reduce the light transmittance of the light-shielding film). Since the refractive index of the black pigment is higher than that of the transparent substrate and the curable resin, increasing the concentration of black pigment in the light-shielding film increases the reflectance when viewed from the side opposite the surface of the transparent substrate on which the light-shielding film is formed. This increases the reflection at the interface between the light-shielding film formed on the transparent substrate and the transparent substrate, causing problems such as reflections on the light-shielding film and the black matrix boundary being noticeable due to the difference in reflectance with the colored portion of the color filter.

Therefore, there is a demand for a photosensitive resin composition for black resist that can produce a light-shielding film that has both high light-shielding properties and low reflectance.

For example, Patent Document 1 discloses a black photosensitive resin composition that is characterized by containing hydrophobic silica particles and a specific dispersant (urethane-based dispersant). It is said that the use of hydrophobic silica particles and a specific dispersant makes it possible to form a black matrix that combines high light blocking properties and low reflectance.

JP 2015-161815 A

However, the inventors' investigations revealed that the black photosensitive resin composition described in Patent Document 1 had problems with jagged edges during pattern formation and the generation of aggregated foreign matter derived from silica particles on the black matrix.

The present invention has been made in consideration of these points, and aims to provide a photosensitive resin composition for black resist that has high light-shielding properties and low reflectance, is capable of forming high-definition patterns, and can suppress the generation of aggregated foreign matter, a light-shielding film obtained by curing the composition, a color filter and touch panel having the light-shielding film, and a display device having the color filter or touch panel.

The photosensitive resin composition for black resist according to the present invention comprises (A) an unsaturated group-containing photosensitive resin, (B) a photopolymerizable compound having at least two or more unsaturated bonds, (C) a photopolymerization initiator, (D) at least one light-shielding component selected from the group consisting of a black pigment, a mixed color pigment, and a light-shielding material, (E) silica particles, and (F) a dispersant, wherein the (F) dispersant has an acid value and an amine value, each of which is 10 mgKOH/g or more and 80 mgKOH/g or less, and the ratio (m F /m _E ) of the total mass (m F ) of the ( _F ) dispersant to the total mass (m _E ) of the ( _E ) silica particles is 0.02 to 0.60.

The method for producing a photosensitive resin composition for black resist according to the present invention comprises mixing (A) an unsaturated group-containing photosensitive resin, (B) a photopolymerizable compound having at least two or more unsaturated bonds, (C) a photopolymerization initiator, (D) a light-shielding component dispersion in which at least one light-shielding component selected from the group consisting of a black pigment, a mixed color pigment, and a light-shielding material is dispersed in a solvent, and (E) a silica particle dispersion in which silica particles are dispersed in a solvent. The silica particle dispersion (E) contains a dispersant (F), and the dispersant (F) has an acid value and an amine value, both of which are 10 mgKOH/g or more and 80 mgKOH/g or less. During the mixing, the ratio (m _F /m E ) of the total mass (m _F ) of the dispersant (F) to the total mass (m _E ) of the silica particles ( _E ) in the photosensitive resin composition for black resist is set to 0.02 to 0.60.

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

The color filter according to the present invention has the above-mentioned light-shielding film as a black matrix.

The touch panel according to the present invention has the above-mentioned light-shielding film.

The display device according to the present invention has the above-mentioned color filter or the above-mentioned touch panel.

The present invention provides a photosensitive resin composition for black resist that has high light-shielding properties and low reflectance, is capable of forming high-definition patterns, and can suppress the generation of aggregated foreign matter, as well as a light-shielding film obtained by curing the composition, a color filter and a touch panel having the light-shielding film, and a display device having the color filter or touch panel.

The present invention will be described in detail below. The photosensitive resin composition for black resist of the present invention (hereinafter abbreviated as "photosensitive resin composition") contains (A) an unsaturated group-containing photosensitive resin, (B) a photopolymerizable compound having at least two unsaturated bonds, (C) a photopolymerization initiator, (D) at least one light-shielding component selected from black pigments, mixed color pigments, and light-shielding materials, (E) silica particles, and (F) a dispersant. Components (A) to (F) will be described below.

1. Component (A) The unsaturated group-containing photosensitive resin, which is component (A) according to the present embodiment, preferably has a polymerizable unsaturated group and an acidic group for exhibiting alkali solubility in one molecule, and more preferably contains both a polymerizable unsaturated group and a carboxy group. The above resin can be widely used without any particular limitation.

An example of the unsaturated group-containing photosensitive resin is an epoxy (meth)acrylate acid adduct obtained by reacting an epoxy compound having two glycidyl ether groups derived from a bisphenol (hereinafter also referred to as a "bisphenol-type epoxy compound represented by general formula (1)") with (meth)acrylic acid, and then reacting the resulting compound having a hydroxy group with a polybasic carboxylic acid or its anhydride. An epoxy compound derived from a bisphenol means an epoxy compound obtained by reacting a bisphenol with an epihalohydrin, or an equivalent thereof. Note that "(meth)acrylic acid" is a general term for acrylic acid and methacrylic acid, and means either or both of these.

The unsaturated group-containing photosensitive resin, component (A), is preferably a bisphenol-type epoxy compound represented by the following general formula (1):

(In formula (1), R ₁ , R ₂ , R ₃ and R ₄ each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogen atom; X 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 general formula (2) or a single bond; and l represents an integer of 0 to 10.)

The bisphenol-type epoxy compound represented by the general formula (1) is an epoxy compound having two glycidyl ether groups obtained by reacting bisphenols with epichlorohydrin. This reaction generally involves oligomerization of the diglycidyl ether compound, and therefore contains an epoxy compound containing two or more bisphenol skeletons.

Examples of bisphenols used in this reaction 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-hydroxyphenyl)hexafluoropropane, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)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 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-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, etc. Among these, bisphenols having a fluorene-9,9-diyl group are preferred.

Examples of (a) dicarboxylic or tricarboxylic acid monoanhydrides that react with the hydroxyl groups in the epoxy (meth)acrylate molecule obtained by reacting such an epoxy compound with (meth)acrylic acid include acid monoanhydrides of chain hydrocarbon dicarboxylic or tricarboxylic acids, acid monoanhydrides of alicyclic dicarboxylic or tricarboxylic acids, and acid monoanhydrides of aromatic dicarboxylic or tricarboxylic acids. Examples of acid monoanhydrides of chain hydrocarbon dicarboxylic or tricarboxylic acids include acid monoanhydrides of 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, and diglycolic acid. Furthermore, acid monoanhydrides of dicarboxylic or tricarboxylic acids into which any substituent has been introduced, etc. are included. Examples of monoanhydrides of alicyclic dicarboxylic or tricarboxylic acids include monoanhydrides of cyclobutanedicarboxylic acid, cyclopentanedicarboxylic acid, hexahydrophthalic acid, tetrahydrophthalic acid, norbornanedicarboxylic acid, and the like. Furthermore, monoanhydrides of dicarboxylic or tricarboxylic acids into which any substituent has been introduced are also included. Examples of monoanhydrides of aromatic dicarboxylic or tricarboxylic acids include monoanhydrides of phthalic acid, isophthalic acid, trimellitic acid, and the like. Furthermore, monoanhydrides of dicarboxylic or tricarboxylic acids into which any substituent has been introduced are also included.

As the (b) tetracarboxylic acid dianhydride to be reacted with the epoxy (meth)acrylate, a chain hydrocarbon tetracarboxylic acid dianhydride, an alicyclic tetracarboxylic acid dianhydride, or an aromatic tetracarboxylic acid dianhydride is used. Here, examples of the chain hydrocarbon tetracarboxylic acid dianhydride include butane tetracarboxylic acid, pentane tetracarboxylic acid, hexane tetracarboxylic acid, and other acid dianhydrides. Furthermore, the acid dianhydride of a tetracarboxylic acid having an arbitrary substituent introduced therein is included. Furthermore, examples of the alicyclic tetracarboxylic acid dianhydride include cyclobutane tetracarboxylic acid, cyclopentane tetracarboxylic acid, cyclohexane tetracarboxylic acid, cycloheptane tetracarboxylic acid, norbornane tetracarboxylic acid, and other acid dianhydrides. Further, the acid dianhydride of a tetracarboxylic acid having an arbitrary substituent introduced therein is included. Furthermore, examples of the aromatic tetracarboxylic acid dianhydride include pyromellitic acid, benzophenone tetracarboxylic acid, biphenyl tetracarboxylic acid, biphenyl ether tetracarboxylic acid, and other acid dianhydrides. Further, the acid dianhydride of a tetracarboxylic acid having an arbitrary substituent introduced therein is included.

The molar ratio (a)/(b) of (a) dicarboxylic or tricarboxylic acid monoanhydride to (b) tetracarboxylic acid dianhydride to be reacted with epoxy (meth)acrylate is preferably 0.01 to 10.0, and more preferably 0.02 or more and less than 3.0. If the molar ratio (a)/(b) deviates from the above range, it is not preferable because the optimal molecular weight for obtaining a photosensitive resin composition with good photopatterning properties cannot be obtained. 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 carboxylic acid or its acid anhydride are not particularly limited, and known methods can be used. The unsaturated group-containing photosensitive resin synthesized by the above reaction preferably has a weight average molecular weight (Mw) of 2000 to 10000 and an acid value of 30 to 200 mgKOH/g. The acid value can be determined by dissolving the resin solution in dioxane and titrating it with a 1/10N-KOH aqueous solution using, for example, a potentiometric titrator "COM-1600" (manufactured by Hiranuma Sangyo Co., Ltd.). The weight average molecular weight (Mw) of the unsaturated group-containing photosensitive resin can be measured, for example, using a gel permeation chromatography (GPC) "HLC-8220GPC" (manufactured by Tosoh Corporation).

Another example of a resin that is preferred as the unsaturated group-containing photosensitive resin, which is component (A), is a copolymer of (meth)acrylic acid, (meth)acrylic acid esters, etc., and includes a resin having a (meth)acryloyl group and a carboxy group. Examples of the above resin include a polymerizable unsaturated group-containing alkali-soluble resin obtained by reacting a copolymer obtained by copolymerizing (meth)acrylic acid esters including glycidyl (meth)acrylate in a solvent with the copolymer, and finally reacting with an anhydride of a dicarboxylic acid or tricarboxylic acid. The above copolymer can be based on JP 2014-111722 A, which is composed of 20 to 90 mol% of repeating units derived from diester glycerol in which hydroxyl groups at both ends are esterified with (meth)acrylic acid, and 10 to 80 mol% of repeating units derived from one or more polymerizable unsaturated compounds copolymerizable therewith, and has a number average molecular weight (Mn) of 2000 to 20,000 and an acid value of 35 to 120 mg KOH/g, and JP 2018-141968 A, which is a polymer having a weight average molecular weight (Mw) of 3000 to 50,000 and an acid value of 30 to 200 mg/KOH, including a unit derived from a (meth)acrylic acid ester compound and a unit having a (meth)acryloyl group and a di- or tricarboxylic acid residue.

As for the unsaturated group-containing photosensitive resin of component (A), one type may be used alone, or two or more types may be used in combination.

2. Component (B) Examples of the photopolymerizable compound having at least two or more unsaturated bonds, which is the component (B) according to the present embodiment, include 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, glycerol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol di ... Examples of the photopolymerizable compound include (meth)acrylic acid esters such as glycerol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, glycerol tri(meth)acrylate, sorbitol penta(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, sorbitol hexa(meth)acrylate, alkylene oxide modified hexa(meth)acrylate of phosphazene, and caprolactone modified dipentaerythritol hexa(meth)acrylate, and dendritic polymers having (meth)acrylic groups as compounds having ethylenic double bonds. Only one of these photopolymerizable compounds may be used alone, or two or more may be used in combination. In addition, the photopolymerizable compound having at least two ethylenic unsaturated bonds can play a role in crosslinking the molecules of the contained alkali-soluble resin, and it is preferable to use one having three or more unsaturated bonds in order to exert this function. Furthermore, the acrylic equivalent, calculated by dividing the molecular weight of the photopolymerizable compound by the number of (meth)acrylic groups in one molecule, is preferably from 50 to 300, and more preferably from 80 to 200. The component (B) does not have a free carboxy group.

An example of a dendritic polymer having a (meth)acryloyl group as a compound having an unsaturated bond that can be included in the composition as component (B) is a dendritic polymer obtained by adding a polyvalent mercapto compound to a portion of the carbon-carbon double bond in the (meth)acryloyl group of a polyfunctional (meth)acrylate. Specifically, this includes a dendritic polymer obtained by reacting a (meth)acryloyl group of a polyfunctional (meth)acrylate represented by the following general formula (3) with a polyvalent mercapto compound represented by the following general formula (4).

(In formula (3), R ₅ is a hydrogen atom or a methyl group, and R ₆ is the remaining portion obtained by donating n hydroxy groups out of k hydroxy groups of R ₇ (OH) _k to the ester bond in the formula. Preferred R ₇ (OH) _k is a polyhydric alcohol based on a non-aromatic straight or branched hydrocarbon skeleton having 2 to 8 carbon atoms, a polyhydric alcohol ether formed by linking a plurality of molecules of the polyhydric alcohol through ether bonds by dehydration condensation of the alcohol, or an ester of such a polyhydric alcohol or polyhydric alcohol ether with a hydroxy acid. k and n independently represent integers of 2 to 20, provided that k≧n.)

(In formula (4), R ₈ is a single bond or a divalent to hexavalent hydrocarbon group having 1 to 6 carbon atoms, and m is 2 when R ₈ is a single bond, and is the same as the valence of R ₈ when R ₈ is a divalent to hexavalent group.)

Examples of polyfunctional (meth)acrylates represented by general formula (3) include (meth)acrylic acid esters such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethylene oxide-modified trimethylolpropane tri(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and caprolactone-modified pentaerythritol tri(meth)acrylate. These compounds may be used alone or in combination of two or more.

Examples of polyvalent mercapto compounds represented by general formula (4) include trimethylolpropane tri(mercaptoacetate), trimethylolpropane tri(mercaptopropionate), pentaerythritol tetra(mercaptoacetate), pentaerythritol tri(mercaptoacetate), pentaerythritol tetra(mercaptopropionate), dipentaerythritol hexa(mercaptoacetate), dipentaerythritol hexa(mercaptopropionate), etc. These compounds may be used alone or in combination of two or more.

The blending ratio of the (A) component to the (B) component is preferably 30/70 to 90/10, more preferably 60/40 to 80/20, in terms of the weight ratio (A)/(B). When the blending ratio of the (A) component is 30/70 or more, the cured product after photocuring is less likely to become brittle, and the acid value of the coating film is less likely to become low in the unexposed areas, so that the decrease in solubility in an alkaline developer can be suppressed. Therefore, problems such as jagged pattern edges and lack of sharpness are less likely to occur. In addition, when the blending ratio of the (A) component is 90/10 or less, the proportion of photoreactive functional groups in the resin is sufficient, so that the desired crosslinked structure can be formed. In addition, since the acid value of the resin component is not too high, the solubility in an alkaline developer in the exposed areas is less likely to become high, so that the formed pattern is less likely to be narrower than the target line width, and pattern loss can be suppressed.

3. Component (C) Examples of the photopolymerization initiator that is the component (C) according to the present embodiment include acetophenones such as acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, dichloroacetophenone, trichloroacetophenone, and p-tert-butylacetophenone, benzophenones such as benzophenone, 2-chlorobenzophenone, and p,p'-bisdimethylaminobenzophenone, benzoin ethers such as benzil, benzoin, benzoin methyl ether, benzoin isopropyl ether, and benzoin isobutyl ether, 2-(o-chlorophenyl)-4,5-phenylbiimidazole, 2-(o-chlorophenyl)-4,5-di(m-methoxyphenyl)biimidazole, 2-(o-fluorophenyl)-4,5-diphenylbiimidazole, 2-(o-methoxyphenyl)-4,5-diphenylbiimidazole, and the like. Biimidazole compounds such as imidazole and 2,4,5-triarylbiimidazole; halomethylthiazole compounds such as 2-trichloromethyl-5-styryl-1,3,4-oxadiazole, 2-trichloromethyl-5-(p-cyanostyryl)-1,3,4-oxadiazole, and 2-trichloromethyl-5-(p-methoxystyryl)-1,3,4-oxadiazole; 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, 2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-1,3,5-triazine halomethyl-S-triazine compounds such as 2-(4-methoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(3,4,5-trimethoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine, and 2-(4-methylthiostyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine; 1,2-octanedione, 1- [4-(phenylthio)phenyl]-, 2-(O-benzoyloxime), 1-(4-phenylsulfanylphenyl)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 and other O-acyloxime compounds; sulfur compounds such as benzyl dimethyl ketal, thioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, 2-methylthioxanthone, and 2-isopropylthioxanthone; anthraquinones such as 2-ethylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, and 2,3-diphenylanthraquinone; organic peroxides such as azobisisobutyronitrile, benzoyl peroxide, and cumene peroxide; thiol compounds such as 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, and 2-mercaptobenzothiazole; and tertiary amines such as triethanolamine and triethylamine. These photopolymerization initiators may be used alone or in combination of two or more kinds.

Examples of O-acyloxime compounds that can be preferably used include O-acyloxime photopolymerization initiators represented by the following general formula (5) and the following general formula (6). Among these compounds, when a light-shielding component is used at a high concentration, it is preferable to use an O-acyloxime photopolymerization initiator having a molar absorption coefficient of 10,000 or more at 365 nm. In the present invention, the term "photopolymerization initiator" is used to include a sensitizer.

(In formula (5), R ₉ and R ₁₀ each independently represent an alkyl group having 1 to 15 carbon atoms, an aryl group having 6 to 18 carbon atoms, an arylalkyl group having 7 to 20 carbon atoms, or a heterocyclic group having 4 to 12 carbon atoms; and R ₁₁ represents an alkyl group having 1 to 15 carbon atoms, an aryl group having 6 to 18 carbon atoms, or an arylalkyl group having 7 to 20 carbon atoms. Here, the alkyl group and the aryl group may be substituted with an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkanoyl group having 1 to 10 carbon atoms, or a halogen, and the alkylene portion may contain an unsaturated bond, an ether bond, a thioether bond, or an ester bond. In addition, the alkyl group may be any of a linear, branched, and cyclic alkyl group.)

(In formula (6), R ₁₂ and R ₁₃ each independently represent a linear or branched alkyl group having 1 to 10 carbon atoms, a cycloalkyl group, a cycloalkylalkyl group, or an 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 ₁₄ each independently represent 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 an -O- group. Furthermore, some of the hydrogen atoms in these groups R ₁₂ to R ₁₄ may be substituted with a halogen atom.)

The amount of the photopolymerization initiator (C) used is preferably 3 parts by weight or more and 30 parts by weight or less, and more preferably 5 parts by weight or more and 20 parts by weight or less, based on 100 parts by weight of the total of the components (A) and (B). When the blending ratio of the (C) component is 3 parts by weight or more, the sensitivity is good and a sufficient photopolymerization speed can be obtained. When the blending ratio of the (C) component is 30 parts by weight or less, the sensitivity is appropriate, and the desired pattern line width and desired pattern edge can be obtained.

4. Component (D) As the light-shielding components such as the black pigment, mixed-color organic pigment and light-shielding material which are the component (D) according to the present embodiment, any known light-shielding components can be used without any particular limitation, so long as they are dispersed with an average particle diameter of 1 to 1000 nm (average particle diameter measured with a laser diffraction/scattering method particle size distribution meter or a dynamic light scattering method particle size distribution meter).

Examples of black pigments, component (D), include perylene black, cyanine black, aniline black, lactam black, carbon black, and titanium black.

Examples of the mixed-color organic pigment, which is component (D), include pigments in which at least two colors are mixed, 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-mentioned (D) component may be used alone or in combination of two or more types depending on the desired function of the photosensitive resin composition.

In addition, 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 names:
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.

The blending ratio of the light-shielding component (D) can be arbitrarily determined depending on the desired light-shielding degree, but is preferably 20% by mass or more and 80% by mass or less, and more preferably 40% by mass or more and 70% by mass or less, based on the total mass of the solid content in the photosensitive resin composition. When an organic pigment such as aniline black, cyanine black, lactam black, or a carbon-based light-shielding component such as carbon black is used as the light-shielding component of the (D) component, it is particularly preferable that the blending ratio is 40% by mass or more and 60% by mass or less, based on the solid content in the photosensitive resin composition. When the light-shielding component is 20% by mass or more based on the solid content in the photosensitive resin composition, sufficient light-shielding properties can be obtained. When the light-shielding component is 80% by mass or less based on the solid content in the photosensitive resin composition, the content of the photosensitive resin that is the original binder is not reduced, and the desired development characteristics and film-forming ability can be obtained.

The above-mentioned (D) component is usually mixed with other formulation components as a light-shielding component dispersion dispersed in a solvent, and a dispersant can be added in this case. The dispersant can be any known compound (compounds commercially available under the names of dispersant, dispersion wetting agent, dispersion promoter, etc.) used for dispersing pigments (light-shielding components) without any particular restrictions.

Examples of dispersants include cationic polymer dispersants, anionic polymer dispersants, nonionic polymer dispersants, and pigment derivative dispersants (dispersion aids). In particular, the above dispersants are preferably cationic polymer dispersants having cationic functional groups such as imidazolyl groups, pyrrolyl groups, pyridyl groups, primary, secondary or tertiary amino groups as adsorption points to the colorant, with an amine value of 1 to 100 mgKOH/g and a number average molecular weight (Mn) in the range of 1000 to 100000. The blending amount of this dispersant is preferably 1 to 35% by mass, more preferably 2 to 25% by mass, relative to the light-shielding component. Note that high-viscosity substances such as resins generally have the effect of stabilizing dispersion, but those that do not have the ability to promote dispersion are not treated as dispersants. However, there is no restriction on using them for the purpose of stabilizing dispersion.

Furthermore, the ratio (m _E /m D ) of the total mass (m _E ) of the (E) silica particles (described below) to the total mass (m _D ) of the ( _D ) light-shielding component is preferably 0.01 to 0.20, and more preferably 0.05 to 0.10. When the ratio of the total mass (m _E ) of the (E) silica particles to the total mass (m _D ) of the (D) light-shielding component is in the above range, it is possible to achieve both high light-shielding properties and low reflectance.

5. Component (E) The silica particles as component (E) are not particularly limited with respect to the production method, such as a gas phase reaction or a liquid phase reaction, and the shape (spherical, non-spherical).

The type of silica particles used as component (E) in the present invention is not particularly limited. Solid silica or hollow silica particles may be used. Note that "hollow silica particles" refer to silica particles that have a cavity inside the particle.

By using the above silica particles, the refractive index of the light-shielding film containing the silica particles can be reduced.

In addition, since it is possible to suppress reflections caused by the difference in refractive index between the transparent substrate and the light-shielding film formed thereon, it is possible to suppress reflections without providing a separate anti-reflection film or the like on the substrate.

The average particle size of the silica particles is preferably 1 to 100 nm, and more preferably 10 to 90 nm. Compared to small particle sizes such as a few nm, it is believed that silica particles are less likely to aggregate with each other when the size is within the above range. As a result, within the above particle size range, the silica particles have excellent dispersion stability and can exist uniformly within the light-shielding film. Therefore, variations in reflectance on the light-shielding film are less likely to occur.

The content of the silica particles is preferably 0.1 to 5 parts by mass, and more preferably 0.1 to 2 parts by mass, based on the total mass of the photosensitive resin composition including the solvent. When the content of the silica particles is within the above range, it is possible to achieve low reflectance while ensuring good photopatterning properties.

The average particle size of the silica particles can be measured by the cumulant method using a dynamic light scattering particle size distribution analyzer "Particle Size Analyzer FPAR-1000" (manufactured by Otsuka Electronics Co., Ltd.).

The refractive index of the silica particles can be 1.10 to 1.47. Ordinary silica particles can have a refractive index of 1.45 to 1.47. In addition, by using hollow silica particles with a low refractive index, the refractive index of the light-shielding film can be made lower than the refractive index of a light-shielding film containing only ordinary silica particles.

The refractive index of silica particles can be determined from a transparent mixture obtained by mixing the silica particles processed into a powder with a standard refractive index liquid having a known refractive index. The refractive index of silica particles can be measured using an Abbe refractometer.

The silica particles may be spherical or elliptical in shape. The silica particles used in the present invention are preferably spherical in shape.

The above silica particles preferably have a sphericity of 1.0 to 1.5. If the sphericity of the silica particles is within this range, the particle shape will be close to a perfect sphere. This allows the silica particles to be uniformly packed into a thin light-shielding film, and a light-shielding film can be formed in which the silica particles are not exposed to the outside from the film surface while maintaining the smoothness of the film surface. This makes it possible to obtain a light-shielding film with a low refractive index and sufficient strength.

The sphericity of the silica particles can be determined from the ratio of the longest diameter to the shortest diameter of the particles (the average value of any 100 silica particles). Here, the longest diameter and the shortest diameter of the silica particles are values determined by photographing the silica particles with a transmission electron microscope and measuring the longest diameter and the shortest diameter of the silica particles from the micrograph obtained.

The silica particles, which are the component (E), can be dispersed in a solvent to form a silica particle dispersion, which can be mixed with other formulation components. The dispersant can be any known compound (compounds commercially available under the names of dispersant, dispersing wetting agent, dispersion promoter, etc.) used in dispersing pigments (light-shielding components) without any particular restrictions. In this embodiment, the silica particle dispersion contains a dispersant (F) described below.

6. Component (F) The dispersant which is the component (F) according to the present embodiment has an acid value and an amine value, and both of the acid value and the amine value are 10 mgKOH/g or more and 80 mgKOH/g or less. When the amine value of the dispersant is 10 mgKOH/g or more, the dispersibility of the silica particles can be increased. On the other hand, a dispersant having only an amine value increases the dispersibility of the silica particles, but reduces the solubility of the silica particles in the developer, so that the silica particles remain as residues at the pattern edge portion, reducing the linearity. On the other hand, when the amine value of the dispersant is 10 mgKOH/g or more and the acid value is also 10 mgKOH/g or more, it is possible to form a high-definition pattern while increasing the dispersibility of the silica particles. On the other hand, by setting both the acid value and the amine value to 80 mgKOH/g or less, the solubility of the silica particles protected by the dispersant in the developer is not excessively increased, and the reduction in the definition of the pattern formed can be suppressed. From the above viewpoints, it is preferable that either the amine value or the acid value of the dispersant is 30 mgKOH/g or more and 80 mgKOH/g or less, and it is more preferable that both are 30 mgKOH/g or more and 80 mgKOH/g or less.

The acid value of the dispersant, which is component (F), means the number of milligrams of KOH required to neutralize 1 g of the resin component (solid content), and can be measured in accordance with JIS-K0070. The amine value of the dispersant, which is component (F), means the number of milligrams of KOH equivalent to the amount of acid (acetic acid, etc.) required to neutralize 1 g of the resin component (solid content), and can be measured in accordance with JIS-K7237.

Examples of the dispersant, which is the above-mentioned component (F), include alkylammonium salts and alkylolammonium salts of acidic polymers, or alkylammonium salts and alkylolammonium salts of polymeric copolymers having acid groups, neutralized salts of polymers having alkylamino groups, and phosphate salts of polymeric copolymers. Among these, alkylammonium salts of acidic polymers or alkylammonium salts of polymeric copolymers having acid groups are preferred. By using alkylammonium salts or alkylolammonium salts of acidic polymers or alkylammonium salts or alkylolammonium salts of polymeric copolymers having acid groups as the dispersant, the generation of aggregated foreign matter derived from silica particles can be more significantly suppressed.

Examples of commercially available dispersants, which are component (F), include DISPERBYK-140, 142, 145, 2001, 2025, and 9076 (all manufactured by BYK Japan, and "DISPERBYK" is a registered trademark of the company). Of the above commercially available products, DISPERBYK-140, 142, and 9076 are preferred, with DISPERBYK-140 and 9076 being more preferred.

The content of the dispersant (F) is preferably 0.01 to 0.5 parts by mass based on the total mass of the photosensitive resin composition including the solvent.

Furthermore, the ratio (m _F /m E ) of the total mass (m _F ) of the (F) dispersant to the total mass (m _E ) of the ( _E ) silica particles is preferably 0.02 to 0.6, more preferably 0.03 to 0.4. When the ratio of the total mass (m _F ) of the (F) dispersant to the total mass (m _E ) of the silica particles is within the above range, the dispersibility of the silica particles is improved while reducing the reflectance on the glass substrate side, and the generation of aggregated foreign matter derived from the silica particles can be suppressed.

The dispersion liquid used in the photosensitive resin composition of the present invention can be prepared by mixing and dispersing the above components (A) to (F) using an appropriate method.

7. Solvent In addition to the components (A) to (F), the photosensitive resin composition of the present invention preferably uses a solvent as component (G). Examples of the solvent 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; cellosolve, methyl cellosolve, ethyl cellosolve, carbitol, methyl carbitol, ethyl carbitol, butyl carbitol, propylene glycol monomethyl ether, and propylene glycol monoethyl ether. Examples of the acetic acid esters include glycol ethers such as dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monomethyl ether, and triethylene glycol monoethyl ether, and acetates 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. By dissolving and mixing these alone or in combination of two or more kinds, a uniform solution-like composition can be obtained.

The photosensitive resin composition of the present invention may also contain additives such as resins other than component (A), such as epoxy resins, curing agents, curing accelerators, thermal polymerization inhibitors and antioxidants, plasticizers, fillers other than silica, leveling agents, defoamers, surfactants, and coupling agents, as necessary.

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, mica, alumina, etc. Examples of defoamers and leveling agents include silicone-based, fluorine-based, and acrylic compounds. Examples of surfactants include fluorine-based surfactants, silicone-based surfactants, etc. Examples of coupling agents include 3-(glycidyloxy)propyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-ureidopropyltriethoxysilane, etc.

The photosensitive resin composition of the present invention preferably contains, in the solid content excluding the solvent (the solid content includes monomers that become solid content after photocuring), an unsaturated group-containing photosensitive resin as component (A), a photopolymerizable compound having at least two unsaturated bonds as component (B), a photopolymerization initiator as component (C), at least one light-shielding component selected from black pigments, mixed color pigments, and light-shielding materials as component (D), silica particles as component (E), and a dispersant as component (F). The amount of the solvent varies depending on the target viscosity, but is preferably 40 to 90% by mass of the total amount.

The photosensitive resin composition of the present invention can be produced as a photosensitive resin composition for black resist by mixing (A) an unsaturated group-containing photosensitive resin, (B) a photopolymerizable compound, (C) a photopolymerization initiator, (D) a light-shielding component dispersion in which a light-shielding component is dispersed in a solvent, and (E) a silica particle dispersion in which silica particles are dispersed in a solvent. The (E) silica particle dispersion contains the above-mentioned (F) dispersant.

By incorporating the dispersant (F) into the silica particle dispersion (E) in advance, the dispersion stability of the silica dispersion can be improved, and it becomes possible to prevent the generation of aggregated foreign matter when it is mixed with other resin components.

A light-shielding film obtained by curing the photosensitive resin composition of the present invention can be obtained, for example, by applying a solution of the photosensitive resin composition to a substrate or the like, drying the solvent, and curing by irradiating with light (including ultraviolet light, radiation, etc.). By using a photomask or the like to provide areas that are exposed to light and areas that are not, only the areas exposed to light are cured and the other areas are dissolved in an alkaline solution, the desired pattern can be obtained.

A color filter or touch panel having the light-shielding film of the present invention as a black matrix can be produced, for example, by forming a light-shielding film having a thickness of 1.0 to 2.0 μm on a transparent substrate, forming red, blue, and green pixels by photolithography after the light-shielding film is formed, and by injecting red, blue, and green inks into the light-shielding film by an inkjet process.

The light-shielding film obtained by curing the photosensitive resin composition of the present invention can also be used as a black column spacer in a liquid crystal display device. For example, a single black resist can be used to create multiple sections with different film thicknesses, with one functioning as a spacer and the other functioning as a black matrix.

Specific examples of each step in the method for forming a light-shielding film by applying and drying a photosensitive resin composition are given below.

The photosensitive resin composition can be applied to a substrate by any of the known methods, such as immersion in a solution, spraying, or using a roller coater, land coater, slit coater, or spinner. After application to the desired thickness by these methods, the solvent is removed (prebaking) to form a coating. Prebaking is performed by heating in an oven or hot plate, vacuum drying, or a combination of these. The heating temperature and heating time in prebaking can be appropriately selected depending on the solvent used, but it is preferable to perform the prebaking at 80 to 120°C for 1 to 10 minutes, for example.

Radiation used for exposure can be, for example, visible light, ultraviolet light, far ultraviolet light, electron beams, X-rays, etc., but the wavelength range of the radiation is preferably 250 to 450 nm. In addition, as a developer suitable for this alkaline development, for example, an aqueous solution of sodium carbonate, potassium carbonate, potassium hydroxide, diethanolamine, tetramethylammonium hydroxide, etc. can be used. These developers can be appropriately selected according to the characteristics of the resin layer, but it is also effective to add a surfactant as necessary. The development temperature is preferably 20 to 35°C, and fine images can be precisely formed using a commercially available developing machine, ultrasonic cleaner, etc. Note that after alkaline development, the film is usually washed with water. As a development processing method, a shower development method, a spray development method, a dip (immersion) development method, a puddle (liquid puddle) development method, etc. can be applied.

After development in this manner, a heat treatment (post-baking) is performed at 180 to 250°C for 20 to 100 minutes. This post-baking is performed for the purpose of increasing the adhesion between the patterned light-shielding film and the substrate. As with pre-baking, this is performed by heating in an oven, hot plate, or the like. The patterned light-shielding film of the present invention is formed through various steps using a photolithography method. Then, polymerization or curing (the two are sometimes collectively referred to as curing) is completed by heat, and a light-shielding film having the desired pattern can be obtained.

As described above, the photosensitive resin composition for black resist of the present invention is not only suitable for forming fine patterns by exposure to light, alkaline development, and other procedures, but also allows a light-shielding film with excellent light-shielding properties, adhesion, electrical insulation, heat resistance, and chemical resistance to be obtained even when a pattern is formed by conventional screen printing.

The photosensitive resin composition for black resist of the present invention can be suitably used as a coating material. In particular, the ink for color filters used in liquid crystal display devices or imaging devices, and the light-shielding film formed therefrom are useful as color filters, black matrices for liquid crystal projection, and the like. The photosensitive resin composition for black resist of the present invention can be used as a color filter ink for color liquid crystal displays, as well as an ink material for color separation or light-shielding in various multicolor display devices such as organic electroluminescent devices represented by organic EL elements, color liquid crystal display devices, color facsimiles, and image sensors. The color filter of the present invention can reduce the reflection of external light at the interface between the colored layer (including the black resist layer) and the substrate, and, for example, the reflection of light emitted from an organic EL element when used in an organic EL element. In other words, it is possible to improve the contrast in bright areas by reducing the reflection of external light, and improve the light-emitting efficiency by improving the light extraction efficiency from the light-emitting side.

The following provides a detailed explanation of the present invention based on examples and comparative examples, but the present invention is not limited to these. Note that in the present invention, when the first decimal place of the content of each component is 0, the decimal point may be omitted.

First, we will explain the synthesis examples of the unsaturated group-containing alkali-soluble resin, which is component (A). Unless otherwise specified, the resins in these synthesis examples were evaluated as follows.

[Solid content concentration]
1 g of the resin solution obtained in Synthesis Example was impregnated into a glass filter (weight: _W0 (g)), weighed ( _W1 (g)), and the weight after heating at 160°C for 2 hours ( _W2 (g)) was calculated from the following formula.
Solid content concentration (wt%) = 100 x (W ₂ - W ₀ )/(W ₁ - W ₀ )

[Acid value]
The resin solution was dissolved in dioxane, and titrated with a 1/10N KOH aqueous solution using a potentiometric titrator "COM-1600" (manufactured by Hiranuma Sangyo Co., Ltd.) to determine the content.

[Molecular weight]
Measurement was performed using gel permeation chromatography (GPC) "HLC-8220GPC" (manufactured by Tosoh Corporation, solvent: tetrahydrofuran, columns: TSKgelSuperH-2000 (2 columns) + TSKgelSuperH-3000 (1 column) + TSKgelSuperH-4000 (1 column) + TSKgelSuperH-5000 (1 column) (manufactured by Tosoh Corporation), temperature: 40°C, speed: 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).

[Average particle diameter]
The average particle size of the silica particles was determined by the cumulant method using a dynamic light scattering particle size distribution analyzer "Particle Size Analyzer FPAR-1000" (manufactured by Otsuka Electronics Co., Ltd.).

The abbreviations used in the Synthesis Examples and Comparative Synthesis Examples are as follows.
BPFE: Bisphenolfluorene type epoxy compound (a reaction product of 9,9-bis(4-hydroxyphenyl)fluorene and chloromethyloxirane. In the compound of general formula (1), X is a fluorene-9,9-diyl group, and R ₁ to R ₄ are hydrogen.)
AA: Acrylic acid BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride THPA: Tetrahydrophthalic anhydride TEAB: Tetraethylammonium bromide PGMEA: Propylene glycol monomethyl ether acetate

[Synthesis Example]
BPFE (114.4g, 0.23 mol), AA (33.2g, 0.46 mol), PGMEA (157g) and TEAB (0.48g) were charged into a 500ml four-neck flask equipped with a reflux condenser, and the mixture was stirred at 100 to 105 ° C for 20 hours to react. Next, BPDA (35.3g, 0.12 mol) and THPA (18.3g, 0.12 mol) were charged into the flask, and the mixture was stirred at 120 to 125 ° C for 6 hours to obtain an unsaturated group-containing alkali-soluble resin (A). The solid content concentration of the obtained resin solution was 56.0 mass%, the acid value (solid content equivalent) was 103 mg KOH / g, and the Mw by GPC analysis was 3600.

The photosensitive resin compositions of Examples 1 to 10 and Comparative Examples 1 to 7 were prepared in the amounts (unit: mass%) shown in Table 1. The ingredients used in Table 1 are as follows:

(Alkali-soluble resin containing unsaturated groups)
(A): Unsaturated group-containing alkali-soluble resin solution (solid content concentration: 56.0% by mass) obtained in the above Synthesis Example

(Photopolymerizable compound)
(B): A mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (Aronix M-405, manufactured by Toagosei Co., Ltd., "Aronix" is a registered trademark of the company)

(Photopolymerization initiator)
(C)-1: Ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(0-acetyloxime) (Irgacure OXE-02, manufactured by BASF Japan, "Irgacure" is a registered trademark of the company)
(C)-2: ADEKA ARCLES NCI-831, manufactured by ADEKA Corporation, "ADEKA ARCLES" is a registered trademark of the company.

(Carbon Black Dispersion)
(D): Carbon black concentration 25.0% by mass, polymer dispersant concentration 2.0% by mass, dispersion resin (alkali-soluble resin (A) of Synthesis Example (solid content 8.0% by mass)) in PGMEA (solid content 35.0% by mass)

(E): PGMEA dispersion of silica particles "YA050C" (manufactured by Admatechs Co., Ltd., solid content concentration 30% by mass, average particle size 50 nm)

(Dispersant)
(F)-1: DISPERBYK-140 (solid content concentration 52% by mass)
(F)-2: DISPERBYK-142 (solid content concentration 60% by mass)
(F)-3: DISPERBYK-9076 (solid content concentration 100% by mass)
(F)-4: DISPERBYK-167 (solid content concentration 52% by mass)
(F)-5: DISPERBYK-170 (solid content concentration 30% by mass)
(F)-6: DISPERBYK-180 (solid content concentration 100% by mass)
(F)-7: DISPERBYK-9077 (solid content concentration 100% by mass)
In addition, (F)-1 to (F)-7 are all manufactured by BYK Japan, and "DISPERBYK" is a registered trademark of the same company.

Furthermore, (F)-1 is a dispersant having an alkyl ammonium salt structure of an acidic polymer, (F)-2 is a phosphate salt type dispersant of a polymer copolymer, (F)-3 is a dispersant having an alkyl ammonium salt structure of a polymer copolymer having an acid group, (F)-4 is a urethane-based dispersant, (F)-5 is a polymer dispersant having an acidic functional group, (F)-6 is an alkylol ammonium salt type dispersant of a copolymer containing an acid group, and (F)-7 is a polymer copolymer having an amine value.

(solvent)
(G)-1: Propylene glycol monomethyl ether acetate (PGMEA)
(G)-2: Cyclohexanone (ANON)

[evaluation]
A light-shielding film for use in the evaluation was prepared by curing a photosensitive resin composition for black resist as follows.

(Preparation of light-shielding film for evaluation)
The photosensitive resin composition shown in Table 1 was applied to a 125 mm x 125 mm glass substrate "#1737" (manufactured by Corning) (hereinafter referred to as "glass substrate"), the surface of which had been cleaned by irradiating it with ultraviolet light having a wavelength of 254 nm and an illuminance of 1000 mJ/ ^cm2 from a low-pressure mercury lamp in advance, so that the film thickness after heat curing treatment would be 1.2 μm, and a light-shielding film was produced by pre-baking it at 90 ° C. for 1 minute using a hot plate. Next, the exposure gap was adjusted to 100 μm, and a negative photomask with a line/space of 10 μm/50 μm was placed on the dried light-shielding film, and ultraviolet light of 50 mJ/ ^cm2 was irradiated from an ultra-high pressure mercury lamp with an i-line illuminance of 30 mW/ ^cm2 to cause a photocuring reaction of the photosensitive portion.

Next, the exposed light-shielding film was subjected to a development process at 25° C. with a 0.04% potassium hydroxide solution at a shower pressure of 1 kgf/cm ² for +10 seconds and +20 seconds from the development time at which a pattern begins to appear (break time = BT), and then washed with water sprayed at 5 kgf/cm ² to remove the unexposed parts of the light-shielding film to form a light-shielding film pattern on a glass substrate, and then main curing (post-baking) was performed at 230° C. for 30 minutes using a hot air dryer to obtain light-shielding films for evaluation according to Examples 1 to 10 and Comparative Examples 1 to 7.

The light-shielding films prepared for evaluation above were evaluated for the following items.

[Pattern linearity evaluation]
(Evaluation Method)
The 10 μm mask pattern after the main curing (post-baking) was observed for jagged edges using an optical microscope and a scanning electron microscope (SEM). The pattern linearity was evaluated in the cases of BT+10 seconds and BT+20 seconds. A score of ◯ or higher was considered to be acceptable.

(Evaluation Criteria)
◯: No jagged edges are observed at the edge of the pattern. △: Jagged edges are observed in some areas at the edge of the pattern. ×: Jagged edges are observed throughout the edge of the pattern.

[Optical Density Evaluation]
(Evaluation Method)
The optical density (OD) of the prepared light-shielding film for evaluation was determined using a Macbeth transmission densitometer. The film thickness of the light-shielding film formed on the substrate was also measured, and the optical density (OD) value was divided by the film thickness to obtain OD/μm.

The optical density (OD) was calculated by the following formula (1).
Optical density (OD) = -log ₁₀ T (1)
(T indicates transmittance)

[Reflectance evaluation]
(Evaluation Method)
The reflectance of the substrate (glass substrate) side of the light-shielding film-attached substrate prepared in the same manner as the light-shielding film for evaluation was measured at an incident angle of 2° using an ultraviolet-visible-infrared spectrophotometer "UH4150" (manufactured by Hitachi High-Tech Science Co., Ltd.).

(Evaluation Criteria)
◯: The reflectance of the substrate side of the substrate with the light-shielding film is 5% or less. Δ: The reflectance of the substrate side of the substrate with the light-shielding film is more than 5% and less than 6%. ×: The reflectance of the substrate side of the substrate with the light-shielding film is 6% or more.

[Evaluation of agglomerated foreign matter]
(Evaluation Method)
After the main curing (post-baking), the light-shielding film for evaluation was observed using an optical microscope to check for the presence or absence of aggregated foreign matter.

(Evaluation Criteria)
◯: No agglomerated foreign matter was found on the light-shielding film △: Agglomerated foreign matter was found on a part of the light-shielding film ×: Agglomerated foreign matter was found on the entire surface of the light-shielding film

The above evaluation results are shown in Table 2.

As shown in Examples 1 to 10, it was found that a highly precise pattern can be formed by using a dispersant whose acid value and amine value are both 10 mgKOH/g or more and 80 mgKOH/g or less. On the other hand, it was found that when both the acid value and amine value are greater than 80 mgKOH/g, the solubility in the developer becomes too high, resulting in poor linearity of the pattern.

In addition, as shown in Examples 1 to 10, it was found that jagged edges of the pattern were eliminated compared to Comparative Examples 2 and 5, in which a dispersant with only an amine value was used. This is thought to be because, although there is a tendency for the solubility in the developer to decrease when a dispersant is adsorbed onto the silica particles, the solubility of the silica particles in the developer was ensured by applying a dispersant with both an acid value and an amine value.

As shown in Examples 1 to 10, it was found that the use of a dispersant with an acid value and an amine value both of which are 10 mgKOH/g or more and 80 mgKOH/g or less can improve the dispersion stability of silica particles and suppress the generation of agglomerated foreign matter. In particular, it was found that in Examples 1 and 3 to 10, which used a polymer dispersant having an alkyl ammonium salt structure, the generation of agglomerated foreign matter originating from silica particles can be significantly suppressed. This is believed to be because the silanol groups present on the surface of the silica particles are effectively protected by the dispersant, improving the dispersion stability in the photosensitive composition for black resist.

As shown in Examples 1 to 10, it was found that by setting the ratio (m _F /m _E ) of the total mass (m _F ) of the (F) dispersant to the total mass (m _E ) of the (E) silica particles to 0.02 to 0.6, it is possible to suppress the formation of aggregated foreign matter derived from the silica particles while suppressing the reflectance on the glass substrate side to 5% or less. If m _F /m _E is smaller than the above range, the dispersion stability of the silica particles is insufficient, resulting in the formation of aggregated foreign matter. On the other hand, if m _F /m _E is larger than the above range, the compatibility of the silica particles becomes too high, so that the particles are not unevenly distributed near the glass substrate, and the reflectance on the glass substrate side becomes greater than 5%.

The photosensitive resin composition of the present invention can provide a photosensitive resin composition for black matrices that combines high light-shielding properties with low reflectance, and a light-shielding film, color filter, and touch panel using the same. In addition, the color filter and touch panel can provide various display devices with excellent visibility.

Claims (10)

(A) an unsaturated group-containing photosensitive resin;
(B) a photopolymerizable compound having at least two unsaturated bonds;
(C) a photopolymerization initiator;
(D) at least one light-shielding component selected from the group consisting of black pigments, mixed color pigments, and light-shielding materials;
(E) silica particles;
(F) a dispersant; and
Including,
the (F) dispersant has an acid value and an amine value, both of which are 10 mgKOH/g or more and 80 mgKOH/g or less, and a ratio (m F /m _E ) of a total mass (m F ) of the (F) dispersant to a total mass (m _E ) of the ( _E ) silica particles is 0.02 to 0.60 _;
A photosensitive resin composition for black resist, wherein the content of the silica particles (E) is 0.1 to 5 parts by mass based on the total mass of the photosensitive resin composition including a solvent . 2. The photosensitive resin composition for black resist according to claim 1, wherein the unsaturated group-containing photosensitive resin (A) is an unsaturated group-containing photosensitive resin obtained by reacting a reaction product of an epoxy compound having two glycidyl ether groups derived from a bisphenol represented by the following general formula (1) with (meth)acrylic acid, and further reacting the reaction product with a polybasic carboxylic acid or an anhydride thereof:

(In formula (1), R ₁ , R ₂ , R ₃ and R ₄ each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogen atom; X 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 general formula (2) or a single bond; and l represents an integer of 0 to 10.)

The photosensitive resin composition for black resist according to claim 1 or 2, wherein the dispersant (F) is a polymeric compound having an alkyl ammonium salt structure. The photosensitive resin composition for black resist according to any one of claims 1 to 3, wherein the average particle size of the silica particles (E) is 1 to 100 nm. The photosensitive resin composition for black resist according to any one of claims 1 to 4, wherein a ratio (m _E /m _D ) of the total mass (m _E ) of the silica particles (E) to the total mass (m _D ) of the light-shielding component (D) is 0.01 to 0.20. (A) an unsaturated group-containing photosensitive resin;
(B) a photopolymerizable compound having at least two unsaturated bonds;
(C) a photopolymerization initiator;
(D) a light-shielding component dispersion in which at least one light-shielding component selected from the group consisting of a black pigment, a mixed color pigment, and a light-shielding material is dispersed in a solvent; and
(E) a silica particle dispersion in which silica particles are dispersed in a solvent;
In a method for producing a photosensitive resin composition for black resist,
The silica particle dispersion (E) contains a dispersant (F),
the (F) dispersant has an acid value and an amine value, both of which are 10 mgKOH/g or more and 80 mgKOH/g or less; the ratio (m F /m E ) of the total mass (m F ) of the (F) dispersant to the total mass (m _E ) of the ( _E ) silica particles in the photosensitive resin composition for a _{black resist} is 0.02 to 0.60;
The production method , wherein the content of the (E) silica particles is 0.1 to 5 parts by mass based on the total mass of the photosensitive resin composition including the solvent . A light-shielding film obtained by curing the photosensitive resin composition for black resist according to any one of claims 1 to 5. A color filter having the light-shielding film according to claim 7 as a black matrix. A touch panel having the light-shielding film according to claim 7. A display device comprising the color filter according to claim 8 or the touch panel according to claim 9.