TWI883152B - Photosensitive resin composition, cured film, substrate, method for manufacturing the substrate, and display device - Google Patents

Abstract

An object of the present invention is to provide a photosensitive resin composition which is capable of forming a cured film having a light scattering function directly on a substrate and excellent adhesion, linearity, solvent resistance and the likes on a substrate, regardless of the heat resistant temperature of the substrate.

The photosensitive resin composition of the present invention comprises (A) an unsaturated group-containing alkali-soluble resin, (B) a photopolymerizable monomer having at least two ethylenically unsaturated bonds, (C) a metal oxide particle or resin particle with a refractive index of 1.2 to 1.5 and an average particle size of 40 to 600 nm., and (D) a photopolymerization initiator, wherein the content of the component (C) is 10% by mass or more and 70% by mass or less with respect to the total mass of the solid content.

Description

Photosensitive resin composition, hardened film, substrate, method for manufacturing substrate, and display device

The present invention relates to a photosensitive resin composition, a cured film formed by curing the photosensitive resin composition, a substrate with a cured film, a method for manufacturing a substrate, and a display device having a cured film or a substrate with a cured film.

In recent years, not only glass substrates or silicon wafers that can be used at high temperatures above 200°C, but also plastic substrates (plastic films, resin films) such as PET (polyethylene terephthalate) and PEN (polyethylene naphthalate) with low heat resistance, or substrates with organic devices such as organic EL devices and organic TFTs, have been examined for the purpose of forming patterns using photosensitive resin compositions with light scattering functions for the purpose of device flexibility or single-chip devices.

Here, when the photosensitive resin composition used to form the pattern by high-temperature sintering is sintered at a low temperature in accordance with the heat resistance of the substrate, the film strength of the pattern formed on the plastic substrate and the substrate with an organic device becomes insufficient, and in the subsequent steps (for example, solvent resistance when applying photoresist or alkali resistance when alkali development, etc.), it is easy to produce undesirable conditions such as film reduction, surface roughness, and pattern peeling.

Therefore, a photosensitive resin composition with light scattering properties that can be used for both high-temperature and low-temperature firing is required.

For example, Patent Document 1 discloses a photosensitive composition for forming a pattern with a light scattering function, which is composed of _TiO2 filler, photopolymerizable (meth) acrylic monomer, alkali-soluble resin, photopolymerization initiator, and organic solvent. The photosensitive composition has photoetching properties suitable for display devices, and has a light scattering property that scatters blue light at a wider angle than the incident angle due to the _TiO2 filler.

Furthermore, Patent Document 2 discloses a resin composition for a light scattering layer, which contains at least one resin (A) as a binder material, fluorine as light scattering particles (B), and at least one metal oxide fine particle selected from the group consisting of ZrO ₂ and TiO ₂ as metal oxide fine particles (C). The above-mentioned resin composition for a light scattering layer has a small wavelength dependence of the light extraction efficiency improvement rate and can be used in a wide wavelength range.

[Prior Art Literature]

[Patent Literature]

Patent document 1: Japanese Patent Publication No. 2013-156304.

Patent document 2: Japanese Patent Publication No. 2015-22794.

However, the inventors of the present invention have found that the photosensitive composition of Patent Document 1 has low solvent resistance, and the light scattering layer resin composition of Patent Document 2 cannot obtain a pattern with the desired light scattering properties. In addition, the photosensitive composition of Patent Document 1 or the light scattering layer resin composition of Patent Document 2 cannot fully satisfy the adhesion or straight line reproducibility of the cured film.

The present invention is made by researchers in view of this point, and its purpose is to provide a photosensitive resin composition that can directly form a cured film having a light scattering function and excellent adhesion, linearity, solvent resistance, etc. on a substrate regardless of the heat resistance temperature of the substrate, a cured film of the cured photosensitive resin composition, a substrate with a cured film, a method for manufacturing a substrate with a cured film, and a display device having a cured film and a substrate with a cured film. Thus, in order to obtain the light scattering function, metal oxide particles with a relatively large refractive index of 1.9 or more are often used. However, in the case where various required properties related to optical properties such as light transmittance or a combination of haze and light scattering intensity are also required, it is expected that a photosensitive resin composition can be provided that can satisfy the required optical properties and other cured film properties even when using metal oxide or resin particles with a refractive index of 1.2 to 1.5.

Furthermore, in recent developments of novel display devices, attempts have been made to expand the design freedom of display devices by applying light scattering layers with specific functions in order to improve the functionality of power saving and color gamut expansion. For example, in order to improve the light extraction efficiency of light-emitting elements such as organic EL, the application of light scattering layers that diffuse and intensify the transmitted light, or the application of light scattering layers that diffuse and intensify the reflected light in display devices that utilize light wavelength conversion of light-emitting elements, is examined, and a photosensitive resin composition that can be applied thereto can be provided.

The photosensitive resin composition of the present invention contains: (A) an alkali-soluble resin containing an unsaturated group, (B) a photopolymerizable monomer having at least two ethylenically unsaturated bonds, (C) metal oxide particles or resin particles having an average particle size of 40 to 600 nm and a refractive index of 1.2 to 1.5, and (D) a photopolymerization initiator, wherein the content of component (C) is 10% by mass or more and 70% by mass or less relative to the total mass of the solid content.

The cured film of the present invention is formed by curing the above-mentioned photosensitive resin composition.

The substrate with a cured film of the present invention has the above-mentioned cured film.

The display device of the present invention has the above-mentioned cured film or the above-mentioned substrate with a cured film.

The manufacturing method of the substrate with a cured film of the present invention is to form a cured film pattern with light scattering properties on a substrate with a heat resistance temperature of 150°C or less to manufacture the substrate with a cured film. The manufacturing method is to apply the above-mentioned photosensitive resin composition on the substrate, expose it through a photomask, remove the unexposed part by development, and heat it at 150°C or less to form a predetermined cured film pattern.

Another method for manufacturing a substrate with a cured film of the present invention is to form a cured film pattern with light scattering properties on a substrate with a heat resistance temperature exceeding 150°C to manufacture a substrate with a cured film. The manufacturing method is to apply the above-mentioned photosensitive resin composition on the substrate, expose it through a photomask, remove the unexposed part by development, and heat it at more than 150°C to form a predetermined cured film pattern.

According to the present invention, a photosensitive resin composition that can directly form a cured film with light scattering function on a substrate regardless of the heat resistance temperature of the substrate, a cured film formed by curing the photosensitive resin composition, a substrate with a cured film, a method for manufacturing a substrate, and a display device having a cured film or a substrate with a cured film can be provided.

The following describes the implementation of the present invention, but the present invention is not limited to the following implementation. In addition, in the present invention, when the first decimal point of the content of each component is 0, the mark after the decimal point is omitted.

The photosensitive resin composition of the present invention contains (A) an alkali-soluble resin containing an unsaturated group. Any resin can be used without particular limitation as long as it has an acid value for imparting alkaline developing properties and can be combined with the photopolymerizable monomer of component (B) to have appropriate photocurability. Among these resins, generally speaking, resins with a high aromatic skeleton tend to have a higher specific gravity than aliphatic resins, and in the case of a solution with the same resin concentration, the specific gravity of the resin solution can be increased. It is speculated that this is beneficial to increase the dispersion stability of metal oxide particles having a larger specific gravity than the resin. Therefore, by using the resin represented by the general formula (1), a photosensitive resin composition having sufficient dispersion stability of metal oxide particles can be obtained. Among them, when X represented by the general formula (1) is a fluorene-9,9-diyl and an alkali-soluble resin containing an unsaturated group (cardo resin) having a polycyclic aromatic skeleton is used, the effect is increased, and it is expected that the dispersion stability of the metal oxide particles is improved. Thereby, the light scattering property of the cured product formed by curing the photosensitive resin composition of the present invention can be improved. In addition, when the cardo resin forms a pattern by photoetching, it has the characteristic of excellent adhesion during development, and when it coexists with an inorganic filler such as a metal oxide, it can also effectively exert this characteristic.

In the photosensitive resin composition of the present invention, the content of component (A) is preferably 25 to 70% by weight relative to the total weight of solids. When the photosensitive resin composition of the present invention is a composition sintered at a low temperature below 150°C, the content of component (A) is preferably 25 to 60% by weight relative to the total weight of solids, and is more preferably 30 to 55% by weight when using cardo resin. When using other acrylic copolymer resins, the content is preferably 25 to 50% by weight. When the content of component (A) is 25% by mass or more, even if metal oxide particles or resin particles having a refractive index of 1.2 to 1.5 are contained, the desired pattern can be obtained without residue by stably dissolving and developing during alkaline development. When the content of component (A) is 60% by mass or less, the suitability of the production process during alkaline development can be improved and the photocurability can be fully ensured. In addition, when the photosensitive resin composition of the present invention is a composition sintered at a high temperature exceeding 150°C, the content of component (A) is preferably 40 to 70% by mass relative to the total mass of the solid content, and more preferably 45 to 60% by mass when using cardo resin. When using other acrylic copolymer resins, it is preferably 40 to 60% by mass or less. When the content of component (A) is 40% by mass or more, even if metal oxide particles or resin particles with a refractive index of 1.2 to 1.5 are contained, they will be dissolved and developed during alkaline development, and the desired pattern can be obtained without residue. When the content of component (A) is 70% by mass or less, the suitability of the production process during alkaline development can be improved, and the photocurability can be fully ensured.

The alkaline soluble resin (A) having a carboxyl group and a polymerizable unsaturated group in one molecule represented by formula (1) of the present invention is obtained by reacting a dicarboxylic acid or a tricarboxylic acid or a monoanhydride thereof (b), and a tetracarboxylic acid or a dianhydride thereof (c) with an epoxy compound (a-1) having two epoxy groups in one molecule and a monocarboxylic acid containing an unsaturated group.

(In formula (1), R ₁ , R ₂ , R ₃ and R ₄ are independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen atom or a phenyl group, R ₅ is a hydrogen atom or a methyl group, X is -CO-, -SO ₂ -, -C(CF ₃ ) ₂ -, -Si(CH ₃ ) ₂ -, -CH ₂ -, -C(CH ₃ ) ₂ -, -O-, fluorene-9,9-diyl or a direct bond, Y is a tetravalent carboxylic acid residue, Z is independently a hydrogen atom or a substituent represented by general formula (2), but at least one of Z is a substituent represented by general formula (2), and the average value of n is 1 to 20)

(However, W is a divalent or trivalent acid residue, and m is 1 or 2)

The method for producing an alkali-soluble resin having a carboxyl group and a polymerizable unsaturated group in one molecule represented by the general formula (1) (hereinafter referred to as "alkali-soluble resin represented by the formula (1)") is described in detail.

First, an epoxy compound (a-1) having two epoxy groups in one molecule represented by general formula (3) (hereinafter, also referred to as "epoxy compound (a-1)") is reacted with a monocarboxylic acid containing an unsaturated group (such as (meth)acrylic acid) to obtain epoxy (meth)acrylate.

(In formula (3), R ₁ , R ₂ , R ₃ and R ₄ are independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen atom or a phenyl group, and X is -CO-, -SO ₂ -, -C(CF ₃ ) ₂ -, -Si(CH ₃ ) ₂ -, -CH ₂ -, -C(CH ₃ ) ₂ -, -O-, fluorene-9,9-diyl or a direct bond)

The epoxy compound (a-1) is an epoxy compound having two glycidyl ether groups obtained by reacting bisphenols with epichlorohydrin.

Examples of bisphenols used as raw materials for the epoxy compound (a-1) include bis(4-hydroxyphenyl)ketone, bis(4-hydroxy-3,5-dimethylphenyl)ketone, bis(4-hydroxy-3,5-dichlorophenyl)ketone, bis(4-hydroxyphenyl)sulfate, bis(4-hydroxy-3,5-dimethylphenyl)sulfate, bis(4-hydroxy-3,5-dichlorophenyl)sulfate, bis(4-hydroxyphenyl)hexafluoropropane, bis(4-hydroxy-3,5-dimethylphenyl)hexafluoropropane, bis( 4-hydroxy-3,5-dichlorophenyl)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-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-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. These may be used alone or in combination of two or more.

Examples of the above-mentioned monocarboxylic acid compounds containing unsaturated groups include, in addition to acrylic acid and methacrylic acid, compounds obtained by reacting acrylic acid or methacrylic acid with acid monoanhydrides such as succinic anhydride, maleic anhydride, and phthalic anhydride.

The reaction of the epoxy compound (a-1) and (meth) acrylic acid can be carried out by a known method. For example, Japanese Patent Publication No. 4-355450 states that by using about 2 mols of (meth) acrylic acid for 1 mol of an epoxy compound having two epoxy groups, a diol compound containing a polymerizable unsaturated group can be obtained. In the present invention, the compound obtained by the above reaction is a diol compound containing a polymerizable unsaturated group, which is a diol (d) containing a polymerizable unsaturated group represented by formula (4) (hereinafter, also referred to as "diol (d) represented by formula (4)").

(In formula (4), R ₁ , R ₂ , R ₃ and R ₄ are independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen atom or a phenyl group, R ₅ is a hydrogen atom or a methyl group, and X is -CO-, -SO ₂ -, -C(CF ₃ ) ₂ -, -Si(CH ₃ ) ₂ -, -CH ₂ -, -C(CH ₃ ) ₂ -, -O-, fluorene-9,9-diyl or a direct bond)

The synthesis of the epoxy (meth)acrylate (d) represented by formula (4), the subsequent addition reaction of a polycarboxylic acid or its anhydride, and the further reaction with a monofunctional epoxy compound having a polymerizable unsaturated group reactive with a carboxyl group, etc., are usually carried out in a solvent using a catalyst as required in the production of the alkali-soluble resin represented by formula (1).

Examples of solvents include: ethyl cellulose acetate, butyl cellulose acetate and other cellulose solvents; diethylene glycol dimethyl ether, ethyl carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate and other high-boiling point ether or ester solvents; cyclohexanone, diisobutyl ketone and other ketone solvents. In addition, the reaction conditions such as the solvent and catalyst used are not particularly limited, but for example, it is preferred to use a solvent that does not have a hydroxyl group and has a boiling point higher than the reaction temperature as a reaction solvent.

In addition, it is preferred to use a catalyst in the reaction between a carboxyl group and an epoxide group. Japanese Patent Publication No. 9-325494 describes ammonium salts such as tetraethylammonium bromide and triethylbenzylammonium chloride; phosphines such as triphenylphosphine and tri(2,6-dimethoxyphenyl)phosphine, etc.

Next, the diol (d) represented by formula (4) obtained by the reaction of the epoxy compound (a-1) and (meth) acrylic acid is reacted with a dicarboxylic acid or a tricarboxylic acid or its anhydride (b), and a tetracarboxylic acid or its dianhydride (c) to obtain an alkali-soluble resin having a carboxyl group and a polymerizable unsaturated group in one molecule represented by formula (1).

(In formula (1), R ₁ , R ₂ , R ₃ and R ₄ are independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen atom or a phenyl group, R ₅ is a hydrogen atom or a methyl group, X is -CO-, -SO ₂ -, -C(CF ₃ ) ₂ -, -Si(CH ₃ ) ₂ -, -CH ₂ -, -C(CH ₃ ) ₂ -, -O-, fluorene-9,9-diyl or a direct bond, Y is a tetravalent carboxylic acid residue, Z is independently a hydrogen atom or a substituent represented by general formula (2), but at least one of Z is a substituent represented by general formula (2), and the average value of n is 1 to 20)

(In formula (2), W is a divalent or trivalent carboxylic acid residue, and m is 1 or 2)

In order to synthesize the alkali-soluble resin represented by formula (1), the acid component used is a polyacid component that can react with the hydroxyl group in the diol (d) molecule represented by formula (4), and a dicarboxylic acid or a tricarboxylic acid or a monoanhydride (b) of such an acid and a tetracarboxylic acid or a dianhydride (c) thereof must be used together. The carboxylic acid residue of the above acid component can be either a saturated hydrocarbon group or an unsaturated hydrocarbon group. In addition, the carboxylic acid residues can also include bonds containing impurities such as -O-, -S-, and carbonyl groups.

The dicarboxylic acid or tricarboxylic acid or the monoanhydride of such acid (b) may be a chain hydrocarbon dicarboxylic acid or tricarboxylic acid, an alicyclic hydrocarbon dicarboxylic acid or tricarboxylic acid, an aromatic hydrocarbon dicarboxylic acid or tricarboxylic acid, or the monoanhydride of such acid, etc.

Examples of acid monoanhydrides of chain alkyl dicarboxylic acids or tricarboxylic acids include acid monoanhydrides of succinic acid, acetyl succinic acid, maleic acid, adipic acid, itaconic acid, azelaic acid, malonic acid, glutaric acid, citric acid, tartaric acid, hydroxyglutaric acid, pimelic acid, sebacic acid, suberic acid, diglycolic acid, and acid monoanhydrides of dicarboxylic acids or tricarboxylic acids introduced with any substituent, etc. In addition, examples of acid monoanhydrides of alicyclic dicarboxylic acids or tricarboxylic acids include acid monoanhydrides of cyclobutane dicarboxylic acid, cyclopentane dicarboxylic acid, hexahydrophthalic acid, tetrahydrophthalic acid, norbornane dicarboxylic acid, and acid monoanhydrides of dicarboxylic acids or tricarboxylic acids introduced with any substituent, etc. In addition, examples of monoanhydrides of aromatic dicarboxylic acids or tricarboxylic acids include monoanhydrides of phthalic acid, isophthalic acid, trimellitic acid, etc., and monoanhydrides of dicarboxylic acids or tricarboxylic acids into which any substituents are introduced.

The preferred monoanhydrides of dicarboxylic acids or tricarboxylic acids are succinic acid, itaconic acid, tetrahydrophthalic acid, hexahydrotrimellitic acid, phthalic acid, and trimellitic acid, and more preferred are succinic acid, itaconic acid, and tetrahydrophthalic acid. Furthermore, the preferred monoanhydrides of dicarboxylic acids or tricarboxylic acids are those used. The monoanhydrides of the above dicarboxylic acids or tricarboxylic acids may be used alone or in combination of two or more.

In addition, the tetracarboxylic acid or its dianhydride (c) may be a chain alkane tetracarboxylic acid, an alicyclic alkane tetracarboxylic acid, an aromatic alkane tetracarboxylic acid, or an dianhydride thereof.

Examples of chain alkyl tetracarboxylic acids include butane tetracarboxylic acid, pentane tetracarboxylic acid, hexane tetracarboxylic acid, and chain alkyl tetracarboxylic acids with substituents such as alicyclic alkyl groups and unsaturated alkyl groups introduced therein. In addition, examples of the above-mentioned alicyclic tetracarboxylic acids include cyclobutane tetracarboxylic acid, cyclopentane tetracarboxylic acid, cyclohexane tetracarboxylic acid, cycloheptane tetracarboxylic acid, norbornane tetracarboxylic acid, and alicyclic tetracarboxylic acids with substituents such as chain alkyl groups and unsaturated alkyl groups introduced therein. In addition, examples of aromatic tetracarboxylic acids include pyromelitic acid, diphenyl ketone tetracarboxylic acid, biphenyl tetracarboxylic acid, diphenyl ether tetracarboxylic acid, diphenyl sulfone tetracarboxylic acid, etc.

Among the tetracarboxylic acids or their dianhydrides, biphenyltetracarboxylic acid, diphenyl ketone tetracarboxylic acid, and diphenyl ether tetracarboxylic acid are preferred, and biphenyltetracarboxylic acid and diphenyl ether tetracarboxylic acid are more preferred. Moreover, among the tetracarboxylic acids or their dianhydrides, their dianhydrides are preferred. Moreover, the above-mentioned tetracarboxylic acids or their dianhydrides may be used alone or in combination of two or more.

The reaction of the diol (d) shown in formula (4) with the acid components (b) and (c) is not particularly limited, and a known method can be used. For example, Japanese Patent Publication No. 9-325494 describes a method of reacting epoxy (meth)acrylate with tetracarboxylic dianhydride at a reaction temperature of 90 to 140°C.

Here, it is preferred to react in such a way that the terminal of the compound becomes a carboxyl group, and the molar ratio of the diol (d) represented by formula (4), the dicarboxylic acid or tricarboxylic acid or the monoanhydride (b) of such acid, and the tetracarboxylic dianhydride (c) becomes (d): (b): (c) = 1: 0.01 to 1.0: 0.2 to 1.0.

For example, when (b) acid monoanhydride and (c) acid dianhydride are used, it is preferred to carry out the reaction in such a manner that the molar ratio of the diol compound (d) containing a polymerizable unsaturated group to the amount of the acid component [(b)/2+(c)] [(d)/[(b)/2+(c)]] becomes 0.5 to 1.0. Here, when the molar ratio is 1.0 or less, the content of the diol compound containing an unreacted polymerizable unsaturated group will not increase, so the temporal stability of the alkali-soluble resin composition can be improved. On the other hand, when the molar ratio exceeds 0.5, the end of the alkali-soluble resin represented by formula (1) will not form anhydride, so the increase in the content of the unreacted acid dianhydride can be suppressed, and the temporal stability of the alkali-soluble resin composition can be improved. In addition, the molar ratio of each component of (d), (b) and (c) can be arbitrarily changed within the above range for the purpose of adjusting the acid value and molecular weight of the alkali-soluble resin represented by formula (1).

Furthermore, the preferred range of the acid value of the alkali-soluble resin represented by formula (1) is preferably 20 to 180 mgKOH/g, more preferably 40 mgKOH/g to 140 mgKOH/g, and even more preferably 80 mgKOH/g to 120 mgKOH/g. When the acid value is 20 mgKOH/g or more, it is not easy to leave residue during alkaline development, and when it is 180 mgKOH/g or less, the alkaline developer will not penetrate too quickly, so stripping development can be suppressed. In addition, the acid value can be obtained by titrating with a 1/10 N-KOH aqueous solution using a potentiometric titration device "COM-1600" (manufactured by Hiranuma Industry Co., Ltd.).

The weight average molecular weight (Mw) of the alkali-soluble resin represented by formula (1) measured by colloid permeation chromatography (GPC) (HLC-8220GPC, manufactured by TOSOH Co., Ltd.) in terms of polystyrene is usually 1,000 to 100,000, preferably 2,000 to 20,000, and more preferably 2,000 to 6,000. When the weight average molecular weight is 1,000 or more, the decrease in pattern adhesion during alkali development can be suppressed. In addition, when the weight average molecular weight is less than 100,000, it is easy to adjust the solution viscosity of the photosensitive resin composition suitable for coating, and alkali development will not be too time-consuming.

The photosensitive resin composition (B) of the present invention contains a photopolymerizable monomer having at least two ethylenic unsaturated bonds. The (B) component can improve the adhesion of the cured product, and the solubility of the exposed part in the alkaline developer is improved, thereby further improving the straight line reproducibility of the cured product. However, in order to prevent the cured product from becoming brittle, inhibit the reduction of the acid value of the composition, improve the solubility of the unexposed part in the alkaline developer, and further improve the straight line reproducibility of the cured product, the amount of the (B) component is preferably not too high.

Here, when the photosensitive resin composition of the present invention is a composition sintered at a low temperature below 150°C, the content of component (B) relative to the total mass of solid content is 10 to 40% by mass. When using cardo resin, component (A) is preferably 10 to 30% by mass. When using other acrylic copolymer resins, component (A) is preferably 10 to 35% by mass.

In addition, when the photosensitive resin composition of the present invention is a composition sintered at a high temperature exceeding 150°C, the content of component (B) is 10 to 40% by mass relative to the total mass of solids. When using cardo resin, component (A) is preferably 10 to 30% by mass. When using other acrylic copolymer resins, component (A) is preferably 10 to 35% by mass.

By setting the content of component (B) to 10 to 40% by mass relative to the total mass of the solid content, the linearity and fineness of the cured film formed by curing the photosensitive resin composition of the present invention can be improved.

Examples of the photopolymerizable monomer (B) having at least two ethylenically unsaturated bonds 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, trihydroxymethylpropane tri(meth)acrylate, trihydroxymethylethane tri(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, Acrylate, dipentatriol tetra(meth)acrylate, glycerol tri(meth)acrylate, sorbitol penta(meth)acrylate, dipentatriol penta(meth)acrylate, dipentatriol hexa(meth)acrylate, sorbitol hexa(meth)acrylate, phosphazene epoxide-modified hexa(meth)acrylate, caprolactone-modified dipentatriol hexa(meth)acrylate and other (meth)acrylates, dendrimers having (meth)acryloyl groups of compounds having ethylenic double bonds, etc. These may be used alone or in combination of two or more.

Examples of the dendrimers having (meth)acryloyl groups of the above-mentioned compounds having ethylenic double bonds include: dendrimers obtained by adding a polyvalent alkyl compound to a portion of the carbon-carbon double bonds in the (meth)acryloyl groups of polyfunctional (meth)acrylates. Specifically, there are dendrimers obtained by reacting the (meth)acryloyl groups of polyfunctional (meth)acrylates represented by general formula (5) with the thiol groups of polyvalent alkyl compounds represented by general formula (6).

(In formula (5), _R6 is a hydrogen atom or a methyl group, and _R7 is one of the k hydroxyl groups of _R9 (OH) _k donated to the remaining portion after the ester bond in the formula. Preferably, _R9 (OH) _k is a polyol based on a non-aromatic straight chain or branched chain hydrocarbon skeleton having 2 to 8 carbon atoms, a polyol ether formed by dehydration condensation of a plurality of molecules of the polyol and linked by ether bonds, or an ester of the polyol or polyol ether with a hydroxy acid. k and l are independently integers ranging from 2 to 20, and k≧1)

(In formula (6), _R8 is a single bond or a divalent to hexavalent C1 to C6 alkyl group, and p is 2 when _R8 is a single bond, and is an integer from 2 to 6 when _R8 is a divalent to hexavalent group)

Examples of the multifunctional (meth)acrylate represented by the general formula (5) 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, trihydroxymethylpropane tri(meth)acrylate, ethylene oxide modified trihydroxymethylpropane tri(meth)acrylate, propylene oxide modified trihydroxymethylpropane tri(meth)acrylate, trihydroxymethylethane tri(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol octa(meth)acrylate, tripentaerythritol hepta(meth)acrylate, hexamethylenetetracycline, octa ... Lactone modified neopentyl tri(meth)acrylate, caprolactone modified neopentyl tri(meth)acrylate, caprolactone modified dipentyl tri(meth)acrylate, epichlorohydrin modified hexahydrophthalic acid di(meth)acrylate, hydroxytrimethylol acetate neopentyl glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide modified neopentyl glycol di(meth)acrylate, epoxy (Meth)acrylates such as propane-modified neopentyl glycol di(meth)acrylate, trihydroxymethylpropane benzoate (meth)acrylate, tri((meth)acryloyloxyethyl) isocyanurate, alkoxy-modified trihydroxymethylpropane tri(meth)acrylate, dipentatriol poly(meth)acrylate, alkyl-modified dipentatriol tri(meth)acrylate, and ditrihydroxymethylpropane tetra(meth)acrylate. These compounds may be used alone or in combination of two or more.

Examples of the polyvalent alkyl compounds represented by the general formula (6) include: 1,2-dialkylethane, 1,3-dialkylpropane, 1,4-dialkylbutane, dialkylethanethiol, trihydroxymethylpropane tri(alkyl acetate), trihydroxymethylpropane tri(alkyl propionate), pentaerythritol tetra(alkyl acetate), pentaerythritol tri(alkyl acetate), pentaerythritol tetra(alkyl propionate), dipentaerythritol hexa(alkyl acetate), dipentaerythritol hexa(alkyl propionate), etc. These compounds may be used alone or in combination of two or more.

Furthermore, when synthesizing the above-mentioned dendrimer, a polymerization inhibitor may be added as needed. Examples of polymerization inhibitors include: hydroquinone compounds and phenol compounds. Specific examples include: hydroquinone, methoxyhydroquinone, o-catechin, tert-butyl o-catechin, cresol, dibutylhydroxytoluene, 2,4,6-tri-tert-butylphenol (BHT), etc.

The photosensitive resin composition of the present invention contains (C) metal oxide particles or resin particles having an average particle size of 40 to 600 nm and a refractive index of 1.2 to 1.5.

The particle size or shape of the metal oxide particles or resin particles with a refractive index of 1.2 to 1.5 is not particularly limited as long as the formed cured film (coating) can exert a light scattering function. The average particle size of the metal oxide particles or resin particles with a refractive index of 1.2 to 1.5 is preferably 40 to 600nm. When the average particle size of the metal oxide particles or resin particles with a refractive index of 1.2 to 1.5 is 40nm or more, the light scattering property caused by the cured product can be expressed and the desired light scattering intensity can be adjusted. When the average particle size of the metal oxide particles or resin particles with a refractive index of 1.2 to 1.5 is 600nm or less, the light transmittance and light scattering intensity can be appropriately adjusted, and the adhesion and straight line reproducibility of the cured product can be fully improved.

Metal oxide particles with a refractive index of 1.2 to 1.5 include silicon oxide particles. Silicon oxide particles are produced by gas phase reaction or liquid phase reaction methods; there is no particular restriction on the shape (spherical, non-spherical, hollow, solid, etc.). In addition, even if the silicon oxide particles have been surface-treated by silane coupling agent treatment, there is no particular restriction as long as the refractive index is 1.2 to 1.5.

The average particle size of the silicon oxide particles can be measured by the cumulative method using a particle size analyzer "Particle Size Analyzer FPAR-1000" (manufactured by Otsuka Electronics Co., Ltd.) using a dynamic light scattering method. The shape of the particles or the hollowness of the hollow particles can be observed and measured using a transmission electron microscope.

Resin particles with a refractive index of 1.2 to 1.5 may be hollow acrylic resin particles, for example. Hollow acrylic resin particles are, for example, hollow particles whose shell portion is a resin obtained by free radical copolymerization of a plurality of monomers having (meth)acrylic groups, and have an average particle size of 40 to 150 nm and a hollow ratio of 10 to 90%. The hollow acrylic resin particles may be produced by the production method described in Japanese Patent Publication No. 2017-66351. The average particle size and hollow ratio may be observed and measured using a transmission electron microscope (TEM).

The metal oxide particles or resin particles of the above-mentioned (C) component can be dispersed in a solvent together with a dispersant as a particle dispersion and mixed with other blending components. The dispersant can be, for example, a known compound used for pigment dispersion (compounds commercially available under the names of dispersants, dispersing wetting agents, dispersing accelerators, etc.), etc., without any particular limitation.

Component (C) can impart light scattering properties to the cured product. However, when the photosensitive resin composition of the present invention contains too much component (C), there is a risk of reducing the adhesion, linear reproducibility, fineness and solvent resistance of the cured film, and the light transmittance through the film is also reduced. Therefore, the content of component (C) is preferably 10% by mass or more and 70% by mass or less relative to the total mass of the solid content.

The photosensitive resin composition of the present invention contains (D) a photopolymerization initiator.

Examples of the component (D) include acetophenones such as acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminoacetophenone, dichloroacetophenone, trichloroacetophenone, and p-tert-butylacetophenone; diphenyl ketones such as phenyl ketone, 2-chlorophenyl ketone, and p,p'-bisdimethylaminophenyl ketone; benzyl, benzoin; benzoin ethers such as benzoin methyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; 2-(o-chlorophenyl)-4,5-phenyldiimidazole, 2-(o-chlorophenyl)-4,5-bis(m-methoxyphenyl)diimidazole, 2-(o-fluorophenyl)-4,5-diphenyldiimidazole, 2-(o-methoxyphenyl)-4,5-diphenyldiimidazole, 2,4,5-triaryldiphenyl Imidazole and other diimidazole compounds; 2-trichloromethyl-5-phenylvinyl-1,3,4-oxadiazole, 2-trichloromethyl-5-(p-cyanophenylvinyl)-1,3,4-oxadiazole, 2-trichloromethyl-5-(p-methoxyphenylvinyl)-1,3,4-oxadiazole and other halogenated methyl diazole compounds; 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, 2-(4-methoxyphenylvinyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(3,4,5-trimethoxyphenylvinyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, 2-(4-methylthiophenylvinyl)-4,6-bis(trichloromethyl)-1,3,5-triazine and other halogenated methyl-s-triazine compounds; 1,2-octanedione-1-[4-(phenylthio)phenyl]-,2-(O-benzoyl oxime), 1-(4-phenylaminophenylsulfonylphenyl)butane-1,2-dione-2-oxime-O-benzoate, 1 O-acyl oxime compounds such as 1-(4-methylaminobenzenesulfonylphenyl)butane-1,2-dione-2-oxime-O-acetate, 1-(4-methylaminobenzenesulfonylphenyl)butane-1-one oxime-O-acetate; diphenylethylenedione dimethyl ketal, thiothione, 2-chlorothiothione, 2,4-diethylthiothione, 2-methylthiothione, 2-isopropylthiothione Sulfur compounds such as ton ketone; anthraquinones such as 2-ethylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-diphenylanthraquinone; organic peroxides such as azobisisobutyronitrile, benzoyl peroxide, and isopropylbenzene peroxide; thiol compounds such as 2-butylbenzimidazole, 2-butylbenzoxazole, and 2-butylbenzothiazole; tertiary amines such as triethanolamine and triethylamine, etc. Moreover, these photopolymerization initiators can be used alone or in combination of two or more.

In particular, when it is desired to increase the amount of metal oxide added, reduce the amount of photopolymerization initiator added, or when it is impossible to perform a heat curing process at a high temperature such as 150°C and to implement photocuring more effectively, in situations where a highly sensitive photopolymerization initiator is necessary, it is preferred to use O-acyl oxime compounds (including ketoxime). Among them, the compound group represented by general formula (7) or general formula (8) can be used as a highly sensitive photopolymerization initiator. Among them, when it is desired to implement photocuring more effectively in response to low-temperature curing, it is preferred to use an O-acyl oxime photopolymerization initiator with a molar absorption coefficient of 10,000 L/mol. cm or more at 365 nm. In addition, the "photopolymerization initiator" in the present invention is used in the sense of including a sensitizer.

(In formula (7), _R10 and _R11 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; _R12 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; the alkyl group and the aryl group may be substituted by an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an acyl group having 1 to 10 carbon atoms, or a halogen; the alkylene moiety may have an unsaturated bond, an ether bond, a thioether bond, or an ester bond; and the alkyl group may be any of a linear, branched, or cyclic alkyl group)

(In formula (8), _R13 and _R14 are independently a linear or branched alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group, cycloalkylalkyl group or alkylcycloalkyl group having 4 to 10 carbon atoms, or a phenyl group which may be substituted by an alkyl group having 1 to 6 carbon atoms; _R15 is independently a linear or branched alkyl group or an alkenyl group having 2 to 10 carbon atoms, and a part of the _-CH2- groups in the alkyl group or the alkenyl group may be substituted by an -O- group; and a part of the hydrogen atoms in the groups _R13 to _R15 may be substituted by a halogen atom)

Here, the content of component (D) is preferably 0.1 to 30% by mass, and more preferably 1 to 25% by mass, relative to the total mass of component (A) and component (B). When the content of component (D) is 0.1% by mass or more, it has a moderate photopolymerization speed, so the sensitivity reduction can be suppressed. When it is less than 30% by mass, the sensitivity of the composition to exposure is not too high, so the line width can be faithfully reproduced for the mask, and the edge of the pattern can be sharper.

The photosensitive resin composition of the present invention may contain (E) epoxy compound as required when curing at a low temperature below 150°C. The content of component (E) is preferably 5 to 35% by mass relative to the solid content. When the photosensitive resin composition contains a sufficient amount of component (E), the solvent resistance of the cured product can be fully improved. However, in order to fully improve the adhesion and straight line reproducibility of the cured product, it is better that the amount of component (E) is not too much.

For example, when the photosensitive resin composition of the present invention is a composition sintered at a low temperature below 150°C, the photosensitive resin composition preferably contains a larger amount of component (E). At this time, the content of component (E) is preferably 5% by mass to 35% by mass relative to the solid content, and more preferably 10% by mass to 25% by mass. In addition, when the photosensitive resin composition of the present invention is a composition sintered at a high temperature exceeding 150°C, in order to make component (E) easy to fully harden, it is better to contain a smaller amount of component (E) than the photosensitive resin composition. At this time, the content of component (E) is preferably 30% by mass or less relative to the solid content.

(E) Examples of epoxy compounds include: bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol 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.), naphthol aralkyl type epoxy compounds, trisphenol methane type epoxy compounds, tetraphenol ethane type epoxy compounds, epoxypropyl ethers of polyols, epoxypropyl esters of polycarboxylic acids, and epoxypropyl (meth)acrylate units represented by copolymers of methacrylic acid and epoxypropyl methacrylate. Copolymers of monomers having (meth)acryloyl groups, aliphatic epoxy compounds represented by 3',4'-epoxyepoxyhexylmethyl 3,4-epoxyepoxyhexane carboxylate, multifunctional epoxy compounds having a dicyclopentadiene skeleton (e.g. HP7200 series, manufactured by DIC Corporation), 1,2-epoxy-4-(2-epoxyethylene)cyclohexane adducts 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.), epoxy compounds having a polysiloxane skeleton, etc.

The epoxy equivalent of the epoxy compound of the component (E) is preferably 100 to 500 g/eq, more preferably 130 to 480 g/eq or less. Moreover, the number average molecular weight (Mn) of the epoxy compound of the component (E) is preferably 100 to 5000. In addition, these compounds may be used in combination of one type or two or more types.

The photosensitive resin composition of the present invention may also contain (F) a curing agent and/or a curing accelerator of an epoxy compound. When the photosensitive resin composition of the present invention is a composition sintered at a low temperature below 150°C, the curing of the (E) component is likely to be insufficient, so the photosensitive resin composition preferably contains a (F) component for sufficiently curing the (E) component.

Examples of curing agents for epoxy compounds of component (F) include: amine compounds, polycarboxylic acid compounds, phenol resins, amine resins, dicyandiamide, Lewis acid complexes, etc. Polycarboxylic acid compounds are preferably used in the present invention.

Examples of polycarboxylic acid compounds include polycarboxylic acids, polycarboxylic acid anhydrides, and polycarboxylic acid thermally decomposable esters. Polycarboxylic acids refer to compounds having two or more carboxyl groups in one molecule, including, for example, succinic acid, maleic acid, cyclohexane-1,2-dicarboxylic acid, cyclohexene-1,2-dicarboxylic acid, cyclohexene-4,5-dicarboxylic acid, norbornane-2,3-dicarboxylic acid, phthalic acid, 3,6-dihydrophthalic acid, 1,2,3,6-tetrahydrophthalic acid, methyltetrahydrophthalic acid, benzene-1,2,4-tricarboxylic acid, cyclohexane-1,2,4-tricarboxylic acid, benzene-1,2,4,5-tetracarboxylic acid, cyclohexane-1,2,4,5-tetracarboxylic acid, butane-1,2,3,4-tetracarboxylic acid, etc. Examples of polycarboxylic acid anhydrides include the anhydrides of the above compounds. It can be an intermolecular anhydride, but generally used is an anhydride with a closed ring in the molecule. Examples of thermally decomposable esters of polycarboxylic acids include: tert-butyl esters of the above compounds, 1-(alkyloxy)ethyl esters, 1-(alkylaminobenzenesulfonyl)ethyl esters (but the alkyl group is a saturated or unsaturated hydrocarbon group with 1 to 20 carbon atoms, the hydrocarbon group may have a branched structure or a ring structure, and may be substituted with any substituent), etc. In addition, polycarboxylic acid compounds may also use polymers or copolymers with more than two carboxyl groups, and the carboxyl groups may be anhydrides or thermally decomposable esters.

In addition, examples of the above-mentioned polymers or copolymers include: polymers or copolymers containing (meth) acrylic acid as a component, copolymers containing maleic anhydride as a component, compounds obtained by reacting tetracarboxylic dianhydride with diamine or diol to open the anhydride ring, etc. Among them, it is preferred to use anhydrides of phthalic acid, 3,6-dihydrophthalic acid, 1,2,3,6-tetrahydrophthalic acid, methyltetrahydrophthalic acid, and benzene-1,2,4-tricarboxylic acid. When using a polycarboxylic acid compound as a curing agent for an epoxy compound, the blending ratio is preferably such that the carboxyl group of the polycarboxylic acid compound becomes 0.5 to 1.5 moles, and more preferably 0.6 to 1.2 moles, relative to 1 mole of the epoxy group of the epoxy compound.

The epoxy compound curing accelerator of component (F) can utilize known compounds such as epoxy compound curing accelerators, curing catalysts, latent curing agents, etc. Examples of epoxy compound curing accelerators include tertiary amines, quaternary ammonium salts, tertiary phosphines, quaternary phosphonium salts, boric acid esters, Lewis acids, organic metal compounds, imidazoles, etc. Among the above curing accelerators, 1,8- diazabicyclo[5.4.0]undecyl-7-ene, or 1,5-diazabicyclo[4.3.0]nona-5-ene, or salts thereof are preferred.

Relative to 100 parts by mass of epoxy compound, the addition amount of the above-mentioned curing accelerator is preferably 0.05 to 2 parts by mass, and the addition amount can be adjusted according to the performance of the chemical resistance of the resin film pattern after thermal curing.

When the photosensitive resin composition of the present invention is a composition sintered at a low temperature of 150°C or less, the total content of the component (E) and the component (F) is preferably 5 to 35% by weight, and more preferably 10 to 30% by weight, relative to the total weight of the solid content. When the total content of the component (E) and the component (F) is 5% by weight or more, the curability when cured at a low temperature of 150°C or less can be fully ensured, and when the total content is 35% by weight or less, the curability can be improved without adversely affecting the patterning property, linearity, and solvent resistance during alkaline development. When the photosensitive resin composition of the present invention is a composition sintered at a high temperature exceeding 150°C, components (E) and (F) may not be added. The combined content of components (E) and (F) is preferably 0 to 25% by mass relative to the total mass of the solid content.

The photosensitive resin composition of the present invention is preferably dissolved in (G) solvent for use.

(G) Examples of solvents contained in the photosensitive resin composition include: alcohols such as methanol, ethanol, n-propanol, isopropanol, ethylene glycol, propylene glycol, 3-methoxy-1-butanol, ethylene glycol monobutyl ether, 3-hydroxy-2-butanone, and diacetone alcohol; 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; cellosol, methylcellosol, ethylcellosol, carbitol, methylcarbitol, ethylcarbitol, butylcarbitol, diethylene glycol, and the like. Glycol ethers such as alcohol ethyl methyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, ethyl lactate, 3-methoxybutyl acetate, 3-methoxy-3-butyl acetate, celoxylate acetate, ethylceloxylate acetate, butylceloxylate acetate, carbitol acetate, ethylcarbitol acetate, butylcarbitol acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, etc. By using these to dissolve and mix, a composition in the form of a uniform solution can be formed. These solvents are used to maintain necessary characteristics such as coating properties, and they can be used alone or in combination of two or more types.

The content of component (G) varies depending on the target viscosity, but is preferably 60 to 90% by mass in the photosensitive resin composition solution.

Furthermore, the photosensitive resin composition of the present invention may be blended with additives such as thermal polymerization inhibitors, antioxidants, plasticizers, levelers, defoamers, coupling agents, and surfactants as needed. Examples of thermal polymerization inhibitors and antioxidants include hydroquinone, hydroquinone monomethyl ether, pyrogallol, tert-butylpyrogallol, phenothiazine, hindered phenol antioxidants, and phosphorus thermal stabilizers. Examples of plasticizers include dibutyl phthalate, dioctyl phthalate, and tricresyl phosphate. Examples of defoamers and levelers include polysilicone, fluorine, and acrylic compounds. Examples of coupling agents include: vinyl trimethoxysilane, 3-methacryloyloxypropyl trimethoxysilane, 3-(epoxypropyloxy)propyl trimethoxysilane, 3-isocyanatopropyl triethoxysilane, 3-aminopropyl triethoxysilane, 3-(anilino)propyl trimethoxysilane, 3-ureidopropyl triethoxysilane. Examples of surfactants include: fluorine-based surfactants, polysilicone-based surfactants, etc.

Next, a method for manufacturing a substrate with a cured film formed by curing the photosensitive resin composition of the present invention is described. The cured film (coating film) of the present invention can be formed by using the photosensitive resin composition of the present invention and by photoetching.

The method for manufacturing the cured film of the present invention is to apply the above-mentioned photosensitive resin composition on a substrate with a heat-resistant temperature of 150°C or less, expose it through a photomask, remove the unexposed part by development, and heat it at a temperature of 150°C or less to form a predetermined cured film pattern.

In addition to the known solution immersion method and spray method, the photosensitive resin composition of the present invention can be applied to the substrate by any method such as a roller coater, a land coater, a slit coater or a rotary machine. After applying to the desired thickness by these methods, the solvent is removed (pre-baking) to form a film. Pre-baking is performed by heating in an oven, a heating plate, etc. The heating temperature and heating time in pre-baking can be appropriately selected according to the solvent used, for example, it can be performed at a temperature of 60 to 110°C (set to not exceed the heat resistance temperature of the substrate) for 1 to 3 minutes.

The exposure after pre-baking is performed by ultraviolet exposure device, and the exposure is performed through the mask, so that only the part of the photoresist corresponding to the pattern is exposed. The exposure device and its exposure conditions can be appropriately selected, and light sources such as ultra-high pressure mercury lamps, high pressure mercury lamps, metal halide lamps, and far ultraviolet lamps are used for exposure, and the photosensitive resin composition in the coating is photocured. It is preferred to perform photocuring by irradiating a fixed amount of light with a wavelength of 365nm.

The radiation used for exposure can be, for example, visible light, ultraviolet light, far ultraviolet light, electron beam, X-ray, etc., but the wavelength range of the radiation is preferably 250 to 450 nm. In addition, the developer suitable for the alkaline development can be, for example, an aqueous solution of sodium carbonate, potassium carbonate, potassium hydroxide, diethanolamine, tetramethylammonium hydroxide, etc. These developers can be appropriately selected in accordance with the characteristics of the resin layer, and surfactants can also be added as needed. The developing temperature is preferably 20 to 35°C, and a commercially available developer or ultrasonic cleaner can be used to accurately form a microscopic image. In addition, water washing is usually performed after alkaline development. The developing method can use shower developing method, spray developing method, immersion developing method, barrel developing method, etc.

Alkaline development after exposure is performed to remove the photoresist in the unexposed part, and the desired pattern is formed by the development. The developer suitable for the alkaline development can be, for example, an aqueous carbonate solution of an alkali metal or alkali earth metal, an aqueous hydroxide solution of an alkali metal, etc. It is preferred to use a weakly alkaline aqueous solution containing 0.05 to 3% by mass of carbonates such as sodium carbonate, potassium carbonate, and lithium carbonate and develop at a temperature of 23 to 28°C. A commercially available developer or ultrasonic cleaner can be used to precisely form a fine image.

After development, it is preferred to perform heat treatment (post-baking) at a temperature of 80 to 140°C (set to not exceed the heat resistance temperature of the substrate) for 20 to 90 minutes, and more preferably at a temperature of 90 to 120°C for 30 to 60 minutes. The above-mentioned post-baking is performed for the purpose of improving the adhesion between the patterned cured film and the substrate. It is performed by heating with an oven, a heating plate, etc. in the same way as pre-baking. The patterned cured film of the present invention is formed by the above-mentioned photoetching method.

The cured film formed by curing the photosensitive resin composition by the above method has a transmittance of 80% or more in the visible light region when the film is formed on the substrate. When the substrate with the cured film is irradiated with white light vertically, the scattered light intensity at 60° when the angle of the straight direct penetrating light is set to 0° is 10% or more and less than 80% relative to the scattered light intensity at 5° when the angle of the straight direct penetrating light is set to 0°. In addition, when measuring the transmittance and scattered light intensity of the substrate with the cured film, a transparent substrate is used, typically a transparent glass substrate (such as Corning Eagle-XG).

Furthermore, for example, in order to improve the light extraction efficiency of organic EL and other light-emitting elements, when a light scattering layer is formed to diffuse and intensify the transmitted light, the intensity of the scattered light at 120° when the angle of the straight-forward direct transmitted light is set to 0° is preferably less than 80%, and more preferably less than 50%, of the intensity of the scattered light at 60° when the angle of the direct transmitted light is set to 0°.

On the other hand, for example, in order to form a light scattering layer that diffuses reflected light to intensify a display device that utilizes wavelength conversion of a light-emitting element, the intensity of scattered light at 120° when the angle of the straight-through direct light is set to 0° is preferably more than 80% of the intensity of scattered light at 60° when the angle of the direct light is set to 0°. In such a use, it is preferred to use magnesium fluoride or hollow silicon oxide with a smaller refractive index. In this use, a wavelength conversion layer can be formed by adding quantum dots or fluorescent substances for wavelength conversion, which highly diffuses the light emitted from the light-emitting element and enhances the light confinement effect.

As mentioned above, the light scattering layer hardened film having various characteristics can be suitable for use in display devices.

In addition, the method for manufacturing the cured film of the present invention is to apply the above-mentioned photosensitive resin composition on a substrate with a heat-resistant temperature exceeding 150°C, expose it through a photomask, remove the unexposed part by development, and heat it at above 150°C to form a predetermined cured film pattern.

The manufacturing method for forming a predetermined cured film pattern on a substrate with a heat-resistant temperature exceeding 150°C is carried out in the same manner as when forming a cured film pattern on a substrate with a heat-resistant temperature below 150°C, and coating, exposure, and development are performed. After development, heat treatment (post-baking) is preferably performed at a temperature of 80 to 250°C and for 20 to 90 minutes, and more preferably at a temperature of 180 to 230°C and a heating time of 30 to 60 minutes. The above-mentioned post-baking is performed for the purpose of improving the adhesion between the patterned cured film and the substrate. It is performed by heating with an oven, a heating plate, etc., similar to pre-baking. The patterned cured film of the present invention is formed through each step of the above-mentioned photoetching method.

The cured film formed by curing the photosensitive resin composition by the above method has a transmittance of 80% or more in the visible light region when the film is formed on the substrate. When the substrate with the cured film is irradiated with white light vertically, the scattered light intensity at 60° when the angle of the straight direct penetrating light is set to 0° is 10% or more and less than 80% relative to the scattered light intensity at 5° when the angle is set to 0°. In addition, when measuring the transmittance and scattered light intensity of the substrate with the cured film, a transparent substrate is used, typically a transparent glass substrate (such as Corning Eagle-XG).

Furthermore, for example, in order to improve the light extraction efficiency of organic EL and other light-emitting elements, when a light scattering layer is formed to intensify the diffused penetrating light, the intensity of the scattered light at 120° when the angle of the straight direct penetrating light is set to 0° is preferably less than 80%, and more preferably less than 50%, of the intensity of the scattered light at 60° when the angle of the straight direct penetrating light is set to 0°.

On the other hand, for example, in order to form a light scattering layer that diffuses reflected light to intensify a display device that utilizes wavelength conversion of a light-emitting element, the intensity of scattered light at 120° when the angle of the straight-forward direct penetrating light is set to 0° is preferably more than 80% of the intensity of scattered light at 60° when the angle of the straight-forward direct penetrating light is set to 0°. In this application, magnesium fluoride or hollow silicon oxide with a smaller refractive index is preferably used. In this application, a wavelength conversion layer can also be formed by adding quantum dots or fluorescent substances for wavelength conversion, which highly diffuses the light emitted from the light-emitting element and enhances the light confinement effect.

As mentioned above, the light scattering layer hardened film having various characteristics can be suitable for use in display devices.

[Implementation example]

The following specifically describes the implementation of the present invention based on embodiments and comparative examples, but the present invention is not limited to them.

First, the synthesis examples of the alkali-soluble resin of component A are described. Unless otherwise specified, the resin evaluation in these synthesis examples is performed as follows. When the same model is used for various measuring machines, the machine manufacturer's name is omitted from the second appearance. In addition, as in [Experiment 1] and [Experiment 2], the glass substrate used to make the substrate with a cured film for measurement is a glass substrate that has been treated in exactly the same way.

[Solid content]

1 g of the resin solution obtained in the Synthesis Example was impregnated in a glass filter [weight: W ₀ (g)] and weighed [W ₁ (g)]. After heating at 160°C for 2 hours, the weight [W ₂ (g)] was determined from the following formula.

Solid content concentration (weight %) = 100 × (W ₂ - _{W 0} ) / (W ₁ - W ₀ ).

[Epoxy equivalent]

After dissolving the resin solution in dioxane, add acetic acid solution of tetraethylammonium bromide and titrate with 1/10N-perchloric acid solution using a potentiometric titration device "COM-1600" (manufactured by Hiranuma Industry Co., Ltd.) to obtain the result.

[Acid value]

The resin solution was dissolved in dioxane and titrated with 1/10N-KOH aqueous solution using a potentiometric titrator "COM-1600" to obtain the result.

[Molecular weight]

The weight average molecular weight (Mw) was determined by colloid permeation chromatography (GPC) "HLC-8220GPC" (manufactured by TOSOH Co., Ltd., solvent: tetrahydrofuran, column: TSKgelSuperH-2000 (2 pieces) + TSKgelSuperH-3000 (1 piece) + TSKgelSuperH-4000 (1 piece) + TSKgelSuper-H5000 (1 piece) (manufactured by TOSOH Co., Ltd.), temperature: 40°C, speed: 0.6 ml/min) and converted to standard polystyrene (PS-Oligomer Kit manufactured by TOSOH Co., Ltd.)

[Refractive index]

The refractive index of silica particles and hollow acrylic resin particles was measured using an ABBE refractometer.

[Average particle size]

The average particle size of silica particles and hollow acrylic resin particles was measured by the cumulative mass method using a particle size distribution meter "Particle Size Analyzer FPAR-1000" (manufactured by Otsuka Electronics Co., Ltd.) using the dynamic light scattering method.

In addition, the abbreviations used in the synthesis examples and comparative synthesis examples are as follows.

DCPMA: dicyclopentyl methacrylate

GMA: Glycidyl Methacrylate

St: Styrene

AA: Acrylic acid

SA: Succinic anhydride

BPFE: Bisphenol fluorene type epoxy compound (reaction product of 9,9-bis(4-hydroxyphenyl)fluorene and chloromethyl oxirane)

BPDA: 3,3’,4,4’-biphenyltetracarboxylic dianhydride

THPA: Tetrahydrophthalic anhydride

PTMA: Pentaerythritol tetra(methylene acetate)

DPHA: A mixture of dipentatriol pentaacrylate and hexaacrylate

TEAB: Tetraethylammonium bromide

AIBN: Azobis(isobutyronitrile)

TDMAMP: tris(dimethylaminomethyl)phenol

HQ: Hydroquinone

TEA: triethylamine

BzDMA: benzyl dimethylamine

PGMEA: Propylene glycol monomethyl ether acetate

[Synthesis example 1]

BPFE (114.4 g, 0.23 mol), AA (33.2 g, 0.46 mol), PGMEA (157 g) and TEAB (0.48 g) were added to a 500 ml four-necked flask with a reflux cooler, and stirred at 100 to 105°C for 20 hours to react. Then, BPDA (35.3 g, 0.12 mol) and THPA (18.3 g, 0.12 mol) were added to the flask, and stirred at 120 to 125°C for 6 hours to obtain an alkali-soluble resin (A)-1 containing polymerizable unsaturated groups. The solid content concentration of the obtained resin solution was 56.1% by mass, the acid value (solid content conversion) was 103 mgKOH/g, and the Mw of GPC analysis was 3600.

[Synthesis example 2]

PGMEA (300 g) was added to a 1L four-neck flask with a reflux cooler, and the flask system was replaced with nitrogen and the temperature was raised to 120°C. A mixture of AIBN (10 g) dissolved in a monomer mixture (DCPMA (77.1 g, 0.35 mol), GMA (49.8 g, 0.35 mol), St (31.2 g, 0.30 mol) was dropped into the flask from a dropping funnel over 2 hours, and further stirred at 120°C for 2 hours to obtain a copolymer solution.

Then, after the flask system was replaced with air, AA (24.0 g (95% of propylene oxide), TDMAMP (0.8 g) and HQ (0.15 g) were added to the obtained copolymer solution, and stirred at 120°C for 6 hours to obtain a copolymer solution containing polymerizable unsaturated groups. Furthermore, SA (30.0 g (90% of the molar number of AA added)) and TEA (0.5 g) were added to the obtained copolymer solution containing polymerizable unsaturated groups, and reacted at 120°C for 4 hours to obtain an alkali-soluble copolymer resin solution (A)-2 containing polymerizable unsaturated groups. The solid content concentration of the resin solution was 41.7% by mass, the acid value (solid content conversion) was 76 mgKOH/g, and the Mw of GPC analysis was 5300.

The blending components used in the photosensitive resin composition of the following embodiments are as follows.

(Alkaline soluble resin containing polymerizable unsaturated groups)

(A)-1: The resin solution obtained in the above-mentioned Synthesis Example 1 (solid content concentration 56.1 mass %).

(A)-2: The resin solution obtained in the above-mentioned Synthesis Example 2 (solid content concentration 41.7 mass %).

(Photopolymerizable monomer)

(B): A mixture of dipentatriol pentaacrylate and dipentatriol hexaacrylate (DPHA (acrylic acid equivalent 96 to 115), manufactured by Nippon Kayaku Co., Ltd.).

(Metal oxide particles or resin particles)

(C)-1: Hollow acrylic particles (techpolymer NH manufactured by Sekisui Chemicals Co., Ltd., average particle size 65nm, porosity 30 volume%, refractive index 1.33) Hollow acrylic particle dispersion with a concentration of 10% by mass and 90% by mass of PGMEA.

(C)-2: Silicon oxide particle dispersion with a concentration of 20% by mass (admanano YA050C manufactured by admatechs, average particle size 50nm, refractive index 1.45), 5% by mass of dispersant (DISPER BYK-355 manufactured by BYK), and 75% by mass of PGMEA.

(C)-3: Silicon oxide particle dispersion with a concentration of 20% by mass of silicon oxide particles (average particle size 400nm, refractive index 1.45), 5% by mass of dispersant (DISPER BYK-355 manufactured by BYK), and 75% by mass of PGMEA.

(C)-4: Silicon oxide particle dispersion with a concentration of 20% by mass of silicon oxide particles (average particle size 600nm, refractive index 1.45), 5% by mass of dispersant (DISPER BYK-355 manufactured by BYK), and 75% by mass of PGMEA.

In addition, the refractive index was measured using a Metricon 2010-M Prism coupler.

(Photopolymerization initiator)

(D): 1,2-octanedione, 1-[4-(phenylthio)phenyl]-,2-(O-benzoyl oxime) (Irgacure OXE-01, manufactured by BASF, "Irgacure" is a registered trademark of the same company).

(Epoxide)

(E)-1: 3,4-Epoxycyclohexanecarboxylic acid (3',4'-epoxycyclohexyl) methyl (celloxide 2021P (epoxy equivalent 135), manufactured by Daicel Co., Ltd.).

(hardener and hardening accelerator)

(F)-1: Benzene 1,2,4-tricarboxylic acid-1,2-anhydride.

(F)-2: PGMEA solution containing 2.0 mass% of 1,8-diazabicyclo[5.4.0]undecyl-7-ene (DBU(R)), manufactured by san-apro Co., Ltd.).

(Solvent)

(G)-1: Propylene glycol monomethyl ether acetate (PGMEA).

(G)-2: Ethyl lactate (EL).

(G)-3: Diethylene glycol ethyl methyl ether (EDM).

(Other additives)

(Coupling agent)

(H)-1: 3-Glycidoxypropyltrimethoxysilane.

(Surfactant)

(H)-2: Megafac F-477 (manufactured by DIC Corporation).

[Experiment 1]

The above-mentioned blending components are blended in the proportions shown in Table 1 to prepare the photosensitive resin compositions of Examples 1 to 4 and Comparative Examples 1 to 2. The values in Table 1 all represent mass %.

[evaluate]

The following evaluations were performed using the photosensitive resin compositions of Examples 1 to 4 and Comparative Examples 1 to 2. The evaluation results are shown in Table 2.

(Production of hardened film (coating) for developing property evaluation)

The photosensitive resin composition shown in Table 1 was irradiated with ultraviolet light of 1000mJ/ ^cm2 at a wavelength of 254nm by a low-pressure mercury lamp, and the surface was cleaned. Then, it was coated on a 125mm×125mm glass substrate "#1737" (made by Corning) (hereinafter also referred to as "glass substrate") using a rotary coater so that the film thickness after heat curing treatment became 2.0μm, and pre-baked at 90℃ for 2 minutes using a heating plate to prepare a hard film (coating). Then, a negative photomask with line/space = 20μm/20μm was coated on the above-mentioned hardened film (coating), and ultraviolet light of 50mJ/ ^cm2 was irradiated by an ultra-high-pressure mercury lamp with an i- ^line irradiance of 30mW/cm2 to perform a photocuring reaction.

Next, the exposed cured film (coating) was developed at 25°C with a 0.04% potassium hydroxide solution using a shower pressure of 1 kgf/ ^cm2 for 20 seconds from the development time (film breaking time = BT) when the pattern began to appear, and then washed with a spray of 5 kgf/ ^cm2 to remove the unexposed portion of the cured film (coating), forming a cured film pattern on a glass substrate, and a hot air dryer was used to perform main curing (post-baking) at 90°C for 60 minutes to obtain substrates with cured films of Examples 1 to 4 and Comparative Examples 1 to 2.

The following items were evaluated for the cured films (coatings) formed by curing the photosensitive resin compositions of Examples 1 to 4 and Comparative Examples 1 to 2 obtained above, and the results are shown in Table 2.

[Development characteristics evaluation]

(Pattern adhesion)

(Evaluation method)

Observe the 20μm mask pattern after primary curing (post-baking) with an optical microscope. In addition, △ and above are qualified.

(Evaluation criteria)

○: Completely unpeeled

△: Partially peeled off

×: Mostly peeled off

(Linearity of pattern)

(Evaluation method)

Observe the 20μm mask pattern after primary curing (post-baking) with an optical microscope. In addition, △ and above are qualified.

(Evaluation criteria)

○: No sawtooth was confirmed on the edge of the pattern

△: It is confirmed that part of the edge of the pattern is saw-toothed

×: Most of the pattern edges are confirmed to be saw-toothed

(Pattern detail)

(Evaluation method)

Observe the 10 to 50μm mask pattern after primary curing (post-baking) with an optical microscope. In addition, △ and above are qualified.

(Evaluation criteria)

◎: Forming a pattern of 10 to 15μm

○: Forming a pattern of 16 to 24μm

△: Forming a pattern of 25 to 50μm

×: No pattern formed

[Solvent resistance evaluation]

(Production of hardened film (coating) for solvent resistance evaluation)

The photosensitive resin composition shown in Table 1 was applied to a glass substrate using a rotary coater in such a way that the film thickness after heat curing treatment became 2.0μm, and pre-baked at 90℃ for 2 minutes using a heating plate to produce a hard film (coating). Then, a negative photomask with line/space = 20μm/20μm was coated on the above hardened film (coating), and irradiated with 50mJ/ ^cm2 of ultraviolet light using an ultra-high pressure mercury lamp with an i-line illumination of 30mW/ ^cm2 to perform a photocuring reaction.

Next, the exposed cured film (coating) was developed at 25°C with a 0.05% potassium hydroxide solution using a shower pressure of 1 kgf/ ^cm2 for 60 seconds, and then washed with a spray of 5 kgf/ ^cm2 to remove the unexposed portion of the cured film (coating), forming a cured film pattern on a glass substrate, and a hot air dryer was used to perform main curing (post-baking) at 90°C for 60 minutes to obtain substrates with cured films of Examples 1 to 4 and Comparative Examples 1 to 2.

(Evaluation method)

The surface of the cured film (coating) made on the glass substrate was wiped back and forth 20 times continuously with a cloth soaked in PGMEA. In addition, △ or above is qualified.

(Evaluation criteria)

○: No dissolution was observed on the surface of the hardened film (coating), and there were no scratches.

△: A very small amount of dissolution was observed on the surface of the hardened film (coating), and a very small amount of scratches were observed.

×: The surface of the hardened film (coating) is softened and most of it has scratches

[Evaluation of penetration rate]

(Evaluation method)

Using the same cured film (coating) as that used for solvent resistance evaluation, the transmittance in the visible light region of 380nm to 780nm was measured using an ultraviolet visible near-infrared spectrophotometer "UH4150" (manufactured by hitachi-hightech Co., Ltd.). In addition, △ or above is qualified.

(Evaluation criteria)

○: Penetration rate is more than 80%

△: The penetration rate is above 70% and below 80%

×: The penetration rate is less than 70%

[Evaluation of light scattering]

White light was vertically irradiated on the same cured film (coating) as that prepared for solvent resistance evaluation, and the penetrating scattered light was measured using a goniophotometer "GP-1" (manufactured by NIKKA DENSOK Co., Ltd.). In addition, △ or above was considered acceptable.

(Light scattering - 1)

○: When the angle of the straight penetrating light is set to 0°, the scattered light intensity at 5° and 60° is evaluated. The light scattering intensity at 60° exceeds 20% compared to the light scattering intensity at 5°.

△: When the angle of the straight-through direct light is set to 0°, the scattered light intensity at 5° and 60° is evaluated. The light scattering intensity at 60° is 10% or more and 20% or less relative to the light scattering intensity at 5°.

×: When the angle of the straight penetrating light is set to 0°, the scattered light intensity at 5° and 60° is evaluated. The light scattering intensity at 60° is less than 10% of the light scattering intensity at 5°.

(Light scattering - 2)

A: When the angle of the straight penetrating light is 0°, the scattered light intensity at 60° and 120° is evaluated. The light scattering intensity at 120° is less than 50% of the light scattering intensity at 60°.

B: When the angle of the straight penetrating light is 0°, the scattered light intensity at 60° and 120° is evaluated. The light scattering intensity at 120° is 50% or more and less than 80% relative to the light scattering intensity at 60°.

C: When the angle of the straight penetrating light is 0°, the scattered light intensity at 60° and 120° is evaluated. The light scattering intensity at 120° is 80% or more compared to the light scattering intensity at 60°.

From the results of Examples 1 to 6 and Comparative Examples 1 to 2, it can be seen that by using a photosensitive resin composition containing an alkali-soluble resin represented by formula (1) of the present invention, hollow acrylic resin particles having specific physical properties (refractive index, average particle size, etc.), and silicon oxide particles, a cured film having excellent light scattering properties and capable of forming fine patterns can be produced. In addition, in the light scattering properties, when light scattering property 1 is ○ and light scattering property 2 is A, it indicates that the diffused penetrating light is strong, and it is suitable as a light extraction efficiency enhancement layer for light emitted from a light-emitting element.

[Experiment 2]

The above-mentioned blending components are blended in the proportions shown in Table 3 to prepare the photosensitive resin compositions of Examples 7 to 12 and Comparative Examples 3 to 4. The values in Table 3 all represent mass %.

[evaluate]

The following evaluations were performed on the cured films (coatings) formed by curing the photosensitive resin compositions of Examples 7 to 12 and Comparative Examples 3 to 4. The evaluation results are shown in Table 4.

(Production of hardened film (coating) for developing property evaluation)

The photosensitive resin composition shown in Table 3 was applied to a glass substrate using a rotary coater in such a way that the film thickness after heat curing treatment became 2.0μm, and pre-baked at 90℃ for 2 minutes using a heating plate to produce a hard film (coating). Then, the exposure gap was adjusted to 100μm, and a negative mask of 10 to 50μm (5μm pattern) was coated on the hardened film (coating), and irradiated with 50mJ/ ^cm2 of ultraviolet light using an ultra-high pressure mercury lamp with an i- ^line illumination of 30mW/cm2 to perform a photocuring reaction.

Next, the exposed cured film (coating) was treated with a 0.04% potassium hydroxide solution at 25°C using a shower pressure of 1 kgf/ ^cm2 , and was developed for 20 seconds from the development time (film breaking time = BT) when the pattern began to appear. It was then washed with a spray of 5 kgf/ ^cm2 to remove the unexposed portion of the cured film (coating), and a cured film pattern was formed on a glass substrate. A hot air dryer was used to perform main curing (post-baking) at 230°C for 30 minutes to obtain substrates with cured films of Examples 5 to 8 and Comparative Examples 3 to 4.

[Development characteristics evaluation]

(Pattern adhesion)

(Evaluation method)

Observe the 20μm mask pattern after primary curing (post-baking) with an optical microscope. In addition, △ and above are qualified.

(Evaluation criteria)

○: Completely unpeeled

△: Partially peeled off

×: Mostly peeled off

(Linearity of pattern)

(Evaluation method)

Observe the 20μm mask pattern after primary curing (post-baking) with an optical microscope. In addition, △ and above are qualified.

(Evaluation criteria)

○: No sawtooth was observed at the edge of the pattern

△: It is confirmed that part of the edge of the pattern is saw-toothed

×: The edges of the pattern are mostly saw-toothed.

(Pattern detail)

(Evaluation method)

Observe the 10 to 50μm mask pattern after primary curing (post-baking) with an optical microscope. In addition, △ and above are qualified.

(Evaluation criteria)

◎: Forming a pattern of 10 to 15μm

○: Forming a pattern of 16 to 24μm

△: Forming a pattern of 25 to 50μm

×: No pattern formed

[Evaluation of penetration rate]

(Evaluation method)

Using the same cured film (coating) as that used for solvent resistance evaluation, use the ultraviolet visible near-infrared spectrophotometer "UH4150" (made by hitachi-hightech Co., Ltd.) to measure the transmittance in the visible light region of 380nm to 780nm. In addition, ○ or above is qualified.

(Evaluation criteria)

○: Penetration rate is more than 80%

△: The penetration rate is above 70% and below 80%

×: The penetration rate is less than 70%

[Evaluation of light scattering]

(Production of hardened film (coating) for light scattering evaluation)

The photosensitive resin composition shown in Table 3 was applied to a glass substrate using a rotary coater in such a way that the film thickness after heat curing treatment became 2.0 μm, and pre-baked at 90°C for 2 minutes using a heating plate to produce a hard film (coating). Then, without covering with a negative mask, 50 mJ/ ^cm2 of ultraviolet light was irradiated with an ultra-high pressure mercury lamp with an i-line illumination of 30 mW/ ^cm2 to perform a photocuring reaction.

Next, the exposed cured film (coating) was developed at 25°C with a 0.05% potassium hydroxide solution using a shower pressure of 1 kgf/ ^cm2 for 20 seconds from the development time (film breaking time = BT) when the pattern began to appear, and then washed with a spray of 5 kgf/ ^cm2 to remove the unexposed portion of the cured film (coating), forming a cured film pattern on the glass substrate, and then main curing (post-baking) was performed at 230°C for 30 minutes using a hot air dryer.

(Evaluation method)

White light was vertically irradiated on the same cured film (coating) as that prepared for solvent resistance evaluation, and the transmitted scattered light was measured using a goniophotometer. In addition, △ or above was considered acceptable.

(Light scattering - 1)

○: When the angle of the straight penetrating light is 0°, the scattered light intensity at 5° and 60° is evaluated. The light scattering intensity at 60° exceeds 20% compared to the light scattering intensity at 5°.

△: When the angle of the straight penetrating light is 0°, the scattered light intensity at 5° and 60° is evaluated. The light scattering intensity at 60° is 10% or more and 20% or less compared to the light scattering intensity at 5°.

×: When the angle of the straight penetrating light is 0°, the scattered light intensity at 5° and 60° is evaluated. The light scattering intensity at 60° is less than 10% of the light scattering intensity at 5°.

(Light scattering - 2)

A: When the angle of the straight penetrating light is 0°, the scattered light intensity at 60° and 120° is evaluated. The light scattering intensity at 120° is less than 50% of the light scattering intensity at 60°.

B: When the angle of the straight penetrating light is 0°, the scattered light intensity at 60° and 120° is evaluated. The light scattering intensity at 120° is 50% or more and less than 80% relative to the light scattering intensity at 60°.

C: When the angle of the straight penetrating light is 0°, the scattered light intensity at 60° and 120° is evaluated. The light scattering intensity at 120° is 80% or more compared to the light scattering intensity at 60°.

From the results of Examples 7 to 12 and Comparative Examples 3 to 4, it can be seen that by using a photosensitive resin composition containing an alkali-soluble resin represented by formula (1) of the present invention, hollow acrylic resin particles having specific physical properties (refractive index, average particle size, etc.), and silicon oxide particles, a cured film having excellent light scattering properties and capable of forming fine patterns can be prepared. In addition, in the light scattering properties, when light scattering property 1 is ○ and light scattering property 2 is A, it indicates that the diffused penetrating light is strong, and it is suitable as a light extraction efficiency enhancement layer for light emitted by a light-emitting element.

[Industrial availability]

According to the photosensitive resin composition of the present invention, a substrate with a cured film having excellent light scattering properties can be obtained. Therefore, it can be used in display devices, etc. In other words, patterns can be formed by photoetching, so it has the advantage of being formed by existing photoetching steps. In addition, the film strength can be obtained even at low temperatures, so it is suitable for making touch panels and color filters using low heat-resistant substrates. The light scattering property can be designed according to the application to meet the required characteristics of the cured film, which can form a light extraction efficiency improvement layer for light emitted by a light-emitting element that must increase the intensity of diffused transmitted light, and can also form a high diffusion/confinement efficiency improvement layer for light emitted by a light-emitting element that must increase the intensity of diffused reflected light.

Claims (13)

A photosensitive resin composition comprises: (A) an alkali-soluble resin containing an unsaturated group, (B) a photopolymerizable monomer having at least two ethylenically unsaturated bonds, (C) metal oxide particles or resin particles having an average particle size of 40 to 600 nm and a refractive index of 1.2 to 1.5, and (D) a photopolymerization initiator, wherein the alkali-soluble resin containing an unsaturated group of component (A) is an alkali-soluble resin containing an unsaturated group represented by general formula (1).

In formula (1), R ₁ , R ₂ , R ₃ and R ₄ are independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a halogen atom or a phenyl group, R ₅ is a hydrogen atom or a methyl group, X is -CO-, -SO ₂ -, -C(CF ₃ ) ₂ -, -Si(CH ₃ ) ₂ -, -CH ₂ -, -C(CH ₃ ) ₂ -, -O-, fluorene-9,9-diyl or a direct bond, Y is a tetravalent carboxylic acid residue, Z is independently a hydrogen atom or a substituent represented by general formula (2), but at least one of Z is a substituent represented by general formula (2), and the average value of n is 1 to 20;

In formula (2), W is a divalent or trivalent carboxylic acid residue, and m is 1 or 2); and the content of component (C) is 10 mass % to 70 mass % relative to the total mass of solids. The photosensitive resin composition as described in claim 1, wherein component C is silicon oxide particles or hollow acrylic resin particles. The photosensitive resin composition as described in claim 1 or 2, wherein the content of component (A) is 25 to 70% by mass relative to the total mass of solids, and the content of component (B) is 10 to 40% by mass relative to the total mass of solids. The photosensitive resin composition as described in claim 1 or 2, wherein the curing agent and/or curing accelerator containing (E) an epoxy compound and (F) an epoxy compound as an optional component, wherein the total content of the component (E) and the component (F) is 5 to 35% by mass relative to the total mass of the solid content. The photosensitive resin composition as described in claim 4, wherein the epoxy compound of component (E) has an epoxy equivalent of 100 to 500 g/eq. The photosensitive resin composition as described in claim 4, wherein the curing agent and/or curing accelerator of component (F) contains an acid anhydride. A cured film formed by curing the photosensitive resin composition described in any one of claims 1 to 6. The hardened film described in claim 7 has a transmittance of 80% or more in the visible light region when formed on a transparent substrate. When the transparent substrate is irradiated with white light vertically, the intensity of scattered light at 60° when the angle of the straight-forward direct penetrating light is set to 0° is 10% or more and less than 80% of the intensity of scattered light at 5° when the angle of the direct penetrating light is set to 0°. The cured film as described in claim 8, wherein in the cured film, the intensity of scattered light at 120° when the angle of the straight direct penetrating light is set to 0° is less than 80% of the intensity of scattered light at 60° when the angle of the direct penetrating light is set to 0°. A substrate with a hardened film, having a hardened film as described in any one of claims 7 to 9. A display device having a hardened film as described in any one of claims 7 to 9 or a substrate with a hardened film as described in claim 10. A method for manufacturing a substrate is to form a cured film pattern with light scattering properties on a substrate with a heat resistance temperature of 150°C or less to manufacture a substrate with a cured film. The method comprises applying a photosensitive resin composition described in any one of claims 1 to 6 on the substrate, exposing the substrate through a photomask, removing the unexposed portion by development, and heating the substrate at a temperature of 150°C or less to form a predetermined cured film pattern. A method for manufacturing a substrate, which is to form a cured film pattern with light scattering properties on a substrate with a heat resistance temperature exceeding 150°C to manufacture a substrate with a cured film, wherein the photosensitive resin composition described in any one of claims 1 to 6 is applied on the substrate, exposed through a photomask, removed the unexposed portion by development, and heated at a temperature exceeding 150°C to form a predetermined cured film pattern.