KR20230128119A - Alkali-soluble resin, photosensitive resin composition, cured product, and image display device - Google Patents

Abstract

An object of the present invention is to provide an alkali-soluble resin capable of forming a cured film with excellent developing adhesion and resolution even when the film is thick, and a photosensitive resin composition containing the alkali-soluble resin. In addition, an object of the present invention is to provide a photosensitive resin composition capable of developing in a short time even when using a weakly alkaline developer, in addition to the above characteristics. Alkali-soluble resin of this invention contains 1 or more types of repeating structural units X represented by following General formula (1). (Wherein, R ¹ is hydrogen or a methyl group, R ² is a linking group having 1 or more carbon atoms, R ³ is an organic group represented by the following general formula (2) bonded to a carbon atom of the linking group, and R ⁴ is the linking group It is a hydroxy group or an organic group bonded to a carbon atom of.) (Wherein, R ⁵ is an organic group having 3 to 8 carbon atoms as a parent and containing a hetero atom, or having 2 to 7 carbon atoms as a parent and having a carboxy group) It is organic.)

Description

Alkali-soluble resin, photosensitive resin composition, cured product, and image display device

The present invention relates to an alkali-soluble resin, a photosensitive resin composition, a cured product, and an image display device.

In a liquid crystal display element, a photo spacer is used to maintain the thickness of a liquid crystal layer sandwiched between a color filter side substrate and a thin film transistor (TFT) side substrate.

A photo spacer is generally formed by applying a photosensitive resin composition to a substrate, drying it, exposing it to light passing through a photo mask having a predetermined fine pattern, and developing it.

[0003] In recent years, with the advancement of image display devices such as liquid crystal display devices (for example, 3D stereoscopic viewing, widening viewing angle, etc.), photo-spacer film thickness (10 μm or more) has been demanded.

For example, in Patent Document 1, even if thick film processing is performed with a film thickness of 10 μm or more, it is excellent in developing adhesion and resolution, and it is possible to form a fine photo-spacer with a good shape. To provide a negative photosensitive resin composition,

(A) an alkali-soluble resin, (B) a photoradical polymerization initiator, and (C) a photopolymerizable monomer, wherein the (C) photopolymerizable monomer is (C-1) a photopolymerizable monomer having an isocyanuric acid skeleton, and (C-2) A negative photosensitive resin composition containing a photopolymerizable monomer having a fluorene skeleton has been proposed.

Further, Patent Document 2 aims to provide a photosensitive resin composition capable of forming a gap of 10 μm or more, having good adhesion to a substrate, and being able to ensure transparency after exposure,

(A) component: a binder polymer, (B) component: a photopolymerizable compound, (C) component: a photopolymerization initiator, and (D) component: a mercapto group-containing hydrogen donor, wherein the (B) photopolymerizable compound, A photosensitive resin composition used as a spacer formation material containing a photopolymerizable compound having an ethylenically unsaturated group and an isocyanuric ring structure has been proposed.

Patent Document 1: Japanese Unexamined Publication No. 2019-124929 Patent Document 2: International Publication No. 2013/115262

However, the photosensitive resin composition described in Patent Literature 1 or 2 had room for improvement with respect to developing adhesiveness and resolution when a photo-spacer was thickened. In addition, from an environmental point of view, a photosensitive resin composition that can be developed with a weakly alkaline aqueous solution is required, but the photosensitive resin composition described in Patent Document 1 or 2 is concerned about the problem that the development time becomes longer and productivity decreases when developed with a weakly alkaline aqueous solution. do.

An object of the present invention is to provide an alkali-soluble resin capable of forming a cured film with excellent developing adhesion and resolution even when the film is thick, and a photosensitive resin composition containing the alkali-soluble resin. In addition, an object of the present invention is to provide a photosensitive resin composition capable of developing in a short time even when using a weakly alkaline developer, in addition to the above characteristics. In addition, an object of the present invention is to provide a cured product obtained from the photosensitive resin composition, and an image display device including the cured product.

As a result of repeated intensive examinations in order to solve the above problems, the present inventors have found that the above object can be achieved by using the following alkali-soluble resin and a photosensitive resin composition containing the alkali-soluble resin, and the present invention reached completion.

The present invention relates to an alkali-soluble resin (hereinafter, also referred to as 'alkali-soluble resin A') containing at least one repeating structural unit X represented by the following general formula (1).

[Formula 1]

(Wherein, R ¹ is hydrogen or a methyl group, R ² is a linking group having 1 or more carbon atoms, R ³ is an organic group represented by the following general formula (2) bonded to a carbon atom of the linking group, and R ⁴ is the linking group It is a hydroxy group or an organic group bonded to the carbon atom of

[Formula 2]

(In the formula, R ⁵ is an organic group having 3 to 8 carbon atoms and containing a hetero atom, or an organic group having 2 to 7 carbon atoms and a carboxy group.)

In addition, the present invention is a repeating structure comprising at least one repeating structural unit X' represented by the following general formula (1'), provided with a branched side chain having 2 to 3 terminals each ending with a radical polymerizable substituent. It relates to an alkali-soluble resin (hereinafter, also referred to as 'alkali-soluble resin B') that does not contain a unit.

[Formula 3]

(Wherein, R ¹ is hydrogen or a methyl group, R ² is a linking group having 1 or more carbon atoms, R ^3' is an organic group represented by the following general formula (2') bonded to a carbon atom of the linking group, and R ⁴ is It is a hydroxy group or an organic group bonded to the carbon atom of the linking group.)

[Formula 4]

(Wherein, R ^5' is a hydrocarbon group having 2 to 7 carbon atoms as a parent, an organic group having 3 to 8 carbon atoms and containing a hetero atom, or an organic group having 2 to 7 carbon atoms and having a carboxy group) device.)

In the alkali-soluble resin A or B, the linking group of R ² is preferably a hydrocarbon group having 1 to 10 carbon atoms as a parent, or an organic group having 1 to 10 carbon atoms as a parent and containing a hetero atom.

In the alkali-soluble resin A or B, the organic group of R ⁴ is an acryloyloxy group, a methacryloyloxy group, an acyloxy group, an amidoxy group, an alkoxy group, an aryloxy group, an amino group, and a nitrogen-containing heterocycle. It is preferable that it is an organic group containing 1 or more types of functional groups selected from the group which consists of.

Further, in the alkali-soluble resin A or B, the linking group of R ² is a hydrocarbon group having 1 to 7 carbon atoms as a parent, or an organic group having 1 to 7 carbon atoms as a parent and containing a hetero atom,

The R ⁴ is preferably a hydroxy group, an acryloyloxy group, or a methacryloyloxy group bonded to the carbon atom of the linking group of the R ² .

Further, in the alkali-soluble resin A or B, the linking group of R ² is a hydrocarbon group having 1 to 7 carbon atoms as a parent, or an organic group having 1 to 7 carbon atoms as a parent and containing a hetero atom,

Said ^R5 or said R5 ^' is an organic group represented by the following general formula (3),

It is preferable that said R ^<4> is a hydroxyl group couple|bonded with the carbon atom of the said linking group of said R ^<2> , an acryloyloxy group, a methacryloyloxy group, or an organic group represented by the following general formula (4).

[Formula 5]

(In the formula, R ⁶ and R ⁷ are each independently a hydrocarbon group having 1 to 6 carbon atoms, and the total carbon atoms of the parent of R ⁶ and R ⁷ are 3 to 8.)

[Formula 6]

(In the formula, R ⁸ is hydrogen or a methyl group, R ⁹ is a hydrocarbon group having 1 to 5 carbon atoms as a parent, or an organic group having 1 to 5 carbon atoms as a parent and containing a hetero atom.)

In the alkali-soluble resin A or B, the content of the repeating structural unit X or X' is preferably 5 to 50 mol% in all repeating structural units.

It is preferable that the said alkali-soluble resin A or B has an acid value of 20-120 mgKOH/g.

It is preferable that the said alkali-soluble resin A or B has a weight average molecular weight of 5000-40000.

The photosensitive resin composition of this invention contains at least the said alkali-soluble resin A and/or B, a polymerizable monomer, and a photoinitiator.

The hardened|cured material of this invention is obtained from the said photosensitive resin composition.

The cured product is preferably a photo spacer, partition material, lens material, interlayer insulating film material, protective film material, optical waveguide material, or flattening film material.

Further, the present invention relates to an image display device including the cured product.

The alkali-soluble resin A or B of the present invention contains at least one repeating structural unit X or X' represented by the general formula (1) or (1'), and the side chain in the repeating structural unit X or X' Its main feature is that it has a length of more than a certain length and has a structure having a carboxy group at the end of its side chain. Alkali-soluble resin A or B of the present invention, due to its characteristic structure, can obtain a cured film excellent in developing adhesion and resolution even when thickened. In addition, since the alkali-soluble resin A or B of the present invention has a hydroxy group or an organic group bonded to the carbon atom of the linking group R ² , it may further have properties derived from these groups. Moreover, since the photosensitive resin composition containing alkali-soluble resin A and/or B of this invention can be developed in a short time even when using a weakly alkaline developer, productivity of hardened|cured materials, such as a photo spacer, can be improved. In particular, when the R ⁴ is an organic group, the alkali-soluble resin A or B of the present invention has a structure in which the side chains are branched, so that a cured film having excellent developing adhesion and resolution can be obtained even when a thick film is formed. For this reason, although not necessarily bound by theory, since the above-mentioned R ³ or R ^3' is somewhat long (a large number of atoms), and the carboxyl group at the terminal tends to face in the direction opposite to the main chain, it may be involved in adhesion with the substrate. This is thought to be due to the increase in the number of carboxyl groups available. In addition, when the R ⁴ is an organic group, the side chain of the alkali-soluble resin A or B has a branched structure, so that the carboxy group at the terminal of the R ³ or R ^3' is more likely to be directed in the direction opposite to the main chain. It can be thought that this is because the number of carboxyl groups that can be involved in adhesion with increases.

Alkali-soluble resin A of this invention contains 1 or more types of repeating structural units X represented by following General formula (1).

[Formula 7]

(Wherein, R ¹ is hydrogen or a methyl group, R ² is a linking group having 1 or more carbon atoms, R ³ is an organic group represented by the following general formula (2) bonded to a carbon atom of the linking group, and R ⁴ is the linking group It is a hydroxy group or an organic group bonded to the carbon atom of

[Formula 8]

(In the formula, R ⁵ is an organic group having 3 to 8 carbon atoms and containing a hetero atom, or an organic group having 2 to 7 carbon atoms and a carboxy group.)

In addition, the alkali-soluble resin B of the present invention contains at least one repeating structural unit X' represented by the following general formula (1'), provided that each branch has 2 to 3 terminals ending with radically polymerizable substituents. It does not contain repeating structural units with one side chain.

[Formula 9]

(Wherein, R ¹ is hydrogen or a methyl group, R ² is a linking group having 1 or more carbon atoms, R ^3' is an organic group represented by the following general formula (2') bonded to a carbon atom of the linking group, and R ⁴ is It is a hydroxy group or an organic group bonded to the carbon atom of the linking group.)

[Formula 10]

(Wherein, R ^5' is a hydrocarbon group having 2 to 7 carbon atoms as a parent, an organic group having 3 to 8 carbon atoms and containing a hetero atom, or an organic group having 2 to 7 carbon atoms and having a carboxy group) device.)

In the present invention, (meth)acryl means acryl or methacryl, (meth)acryloyl means acryloyl or methacryloyl, (meth)acrylic acid means acrylic acid or methacrylic acid, and (meth)acrylate means acryl rate or methacrylate, respectively. In the present invention, the number of carbon atoms in the parent body means the number of carbon atoms in the main skeleton excluding substituents.

In Formula (1) or (1′), R ² is a linking group having 1 or more carbon atoms, and R ³ and R ⁴ , or R ^3′ and R ⁴ are linked to an oxygen atom of an ester bond. It is not particularly limited as long as it is a group having 1 or more carbon atoms. As the linking group, for example, a linear or branched aliphatic saturated or unsaturated hydrocarbon group, an alicyclic saturated or unsaturated hydrocarbon group (including crosslinked or condensed rings), an aromatic hydrocarbon group, and a carbon atom constituting the hydrocarbon group organic groups in which a part of is substituted with a hetero atom (for example, an oxygen atom, a nitrogen atom, a sulfur atom, etc.), and an organic group in which two or more kinds thereof are bonded. In addition, the hydrocarbon group or the organic group may include various substituents (e.g., halogen, hydroxyl, carboxy, amino, alkyl, alkenyl, alkoxy, and aryl groups) or functional groups (e.g., ester bond, amide bond, ether bond, thioether bond, urethane bond, etc.) may be present.

The linking group is preferably a parent hydrocarbon group having 1 to 10 carbon atoms or an organic group having 1 to 10 carbon atoms and containing a hetero atom (eg, oxygen atom, nitrogen atom, and sulfur atom). . In addition, the linking group is a parent hydrocarbon group having 1 to 7 carbon atoms or an organic group having 1 to 7 carbon atoms and containing a hetero atom (eg, an oxygen atom, a nitrogen atom, and a sulfur atom). more preferable In addition, when the linking group includes a hetero atom, the hetero atom possessed by the linking group is a portion other than a bonded portion to R ³ or R ^3' in the general formula (1) or (1'), the above It has it at a part other than the bonding part with R ⁴ and a part other than the bonding part with the ester bond oxygen atom. In addition, the linking group is a linear or branched aliphatic saturated or unsaturated hydrocarbon group having 2 to 7 carbon atoms in the parent, an alicyclic saturated or unsaturated hydrocarbon group having 3 to 7 carbon atoms in the parent, and a carbon number of 4 to 7 in the parent In addition, a hydrocarbon group in which a methylene group and an alicyclic saturated or unsaturated hydrocarbon group are bonded, a hydrocarbon group in which the parent has 5 to 7 carbon atoms and a linear or branched aliphatic saturated or unsaturated hydrocarbon group and an alicyclic saturated or unsaturated hydrocarbon group are bonded, or a parent carbon number is 2 to 7 and is more preferably an organic group containing an ether bond.

In the general formula (1), the R ³ is an organic group represented by the general formula (2) bonded to a carbon atom of the linking group of the R ² . In the general formula (2), the R ⁵ is an organic group having 3 to 8 carbon atoms and containing a hetero atom (eg, an oxygen atom, a nitrogen atom, and a sulfur atom), or a parent It is an organic group having 2 to 7 carbon atoms and also having a carboxyl group. The R ⁵ is preferably an organic group having 2 to 7 carbon atoms and a carboxy group. When the R ⁵ has a carboxy group, the number of carboxy groups is not particularly limited, but is preferably 1 to 2. The organic group may include various substituents (eg, halogen, hydroxyl, carboxy, amino, alkyl, alkenyl, alkoxy, and aryl groups) or functional groups (eg, ester bond, amide bond, ether bond, thio ether linkages, urethane linkages, etc.) may be present.

It is preferable that the organic group represented by the said General formula (2) is any one of the following organic groups.

[Formula 11]

In the above general formula (1'), the above R ^3' is an organic group represented by the above general formula (2') bonded to a carbon atom possessed by the linking group of the above R ² . In the above general formula (2'), the R ^5' is a hydrocarbon group having 2 to 7 carbon atoms as a parent, a hydrocarbon group having 3 to 8 carbon atoms as a parent, and a hetero atom (eg, an oxygen atom, a nitrogen atom, and sulfur atom, etc.), or an organic group having 2 to 7 carbon atoms in the parent body and also having a carboxy group. The R ^{5 '} is preferably a hydrocarbon group having 2 to 7 carbon atoms as a parent or an organic group having 2 to 7 carbon atoms and a carboxy group. When R ^5' has a carboxy group, the number of carboxy groups is not particularly limited, but is preferably 1 to 2. Examples of the hydrocarbon group include a linear or branched aliphatic saturated or unsaturated hydrocarbon group, an alicyclic saturated or unsaturated hydrocarbon group (including cross-exchanged and condensed rings), an aromatic hydrocarbon group, and a hydrocarbon group in which two or more of these are bonded. etc. can be mentioned. The hydrocarbon group or the organic group may be formed by various substituents (eg, halogen, hydroxyl, carboxy, amino, alkyl, alkenyl, alkoxy, aryl, etc.) or functional groups (eg, ester bond, amide bond). , ether linkage, thioether linkage, urethane linkage, etc.).

It is preferable that the organic group represented by the said General formula (2') is any one of the following organic groups.

[Formula 12]

Moreover, in the said General formula (2) or (2'), it is preferable that said ^R5 or ^R5' is an organic group represented by the following general formula (3).

[Formula 13]

(In the formula, R ⁶ and R ⁷ are each independently a hydrocarbon group having 1 to 6 carbon atoms, and the total carbon atoms of the parent of R ⁶ and R ⁷ are 3 to 8.)

As said hydrocarbon group, a linear or branched aliphatic saturated or unsaturated hydrocarbon group, an aromatic hydrocarbon group, an alicyclic saturated or unsaturated hydrocarbon group, etc. are mentioned. The said hydrocarbon group may have various substituents (for example, a halogen group, a hydroxyl group, a carboxy group, an amino group, an alkyl group, an alkenyl group, an alkoxy group, and an aryl group etc.).

As an example of the organic group represented by the said General formula (3), the following thing is mentioned.

[Formula 14]

It is preferable that each of R ⁶ and R ⁷ independently represents a hydrocarbon group having 1 to 5 carbon atoms, and the total number of carbon atoms in the parent of R ⁶ and R ⁷ is 3 to 7.

It is preferable that the organic group represented by the said General formula (2) or (2') is any one of the following organic groups.

[Formula 15]

In the general formula (1) or (1'), R ⁴ is a hydroxy group or an organic group bonded to a carbon atom of the linking group of R ² . When the above R ⁴ is a hydroxyl group, developability can be further improved. In addition, when R ⁴ is an organic group, properties derived from the organic group (eg developability, adhesion, solubility, etc.) can be further imparted. The organic group is not particularly limited, and includes, for example, a linear or branched aliphatic saturated or unsaturated hydrocarbon group, an alicyclic saturated or unsaturated hydrocarbon group (including bridged or condensed ring), an aromatic hydrocarbon group, or the hydrocarbon group. organic groups in which some of the constituting carbon atoms are substituted with heteroatoms (eg, oxygen atoms, nitrogen atoms, sulfur atoms, etc.), and organic groups in which two or more of these atoms are bonded; and the like. In addition, the hydrocarbon group or the organic group is various substituents (eg, halogen, hydroxyl, carboxy, amino, alkyl, alkenyl, alkoxy, aryl, etc.) or functional groups (eg, ester bond, amide bond, ether bond, thioether bond, urethane bond, etc.) may be present.

The organic group for R ⁴ is at least one functional group selected from the group consisting of an acryloyloxy group, a methacryloyloxy group, an acyloxy group, an amideoxy group, an alkoxy group, an aryloxy group, an amino group, and a nitrogen-containing heterocycle. It is preferable that it is an organic group containing, and it is more preferable that it is an acryloyloxy group, a methacryloyloxy group, or an organic group represented by any one of the following formulas.

[Formula 16]

(In the formula, R ¹⁰ and R ¹¹ are each independently an organic group described in paragraph [0039].)

Moreover, it is preferable that said R ^<4> is a hydroxyl group couple|bonded with the carbon atom of the said linking group of said R ^<2> , an acryloyloxy group, a methacryloyloxy group, or an organic group represented by the following general formula (4).

[Formula 17]

(In the formula, R ⁸ is hydrogen or a methyl group, R ⁹ is a hydrocarbon group having 1 to 5 carbon atoms as a parent, or an organic group having 1 to 5 carbon atoms as a parent and containing a hetero atom.)

In the general formula (4), the R ⁹ is a hydrocarbon group having 1 to 5 carbon atoms as a parent, or a heteroatom (eg, an oxygen atom, a nitrogen atom, and sulfur having 1 to 5 carbon atoms as a parent) It is an organic group containing atoms, etc.). In addition, when the organic group contains a heteroatom, the heteroatom possessed by the organic group is a part other than the bonded portion with the nitrogen atom of the urethane bond in the above general formula (4), and the oxygen of the (meth)acryloyloxy group It is held in a part other than the bonding part with an atom. As said hydrocarbon group, a linear or branched aliphatic saturated or unsaturated hydrocarbon group is mentioned. The hydrocarbon group or the organic group may be formed by various substituents (eg, halogen, hydroxyl, carboxy, amino, alkyl, alkenyl, alkoxy, aryl, etc.) or functional groups (eg, ester bond, amide bond). , ether linkage, thioether linkage, urethane linkage, etc.). The R ⁹ is preferably a hydrocarbon group having 1 to 5 carbon atoms in the parent body, and more preferably an ethylene group or a propylene group.

Examples of monomers underlying repeating structural units other than the repeating structural unit X or X' constituting the alkali-soluble resin A or B include (meth)acrylic acid and 2-(meth)acryloyloxyethylsuccinic acid. , maleic acid, and carboxyl group-containing monomers such as itaconic acid; carboxylic acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; Methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, benzyl (meth)acrylate, lauryl (meth)acrylate, hydroxyethyl (meth)acrylate alkyl (meth)acrylates such as hydroxypropyl (meth)acrylate, ethoxyethyl (meth)acrylate, and glycidyl (meth)acrylate; and alicyclic (meth)acrylates such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, and dicyclopentenyl (meth)acrylate. In addition, styrene, cyclohexyl maleimide, phenyl maleimide, methyl maleimide, ethyl maleimide, n-butyl maleimide, lauryl maleimide, and a silicon-containing monomer may be used as copolymerization monomers. These monomers may be used independently or may use 2 or more types together.

However, the alkali-soluble resin B does not include a repeating structural unit (hereinafter, also referred to as 'repeating structural unit Y') having a branched side chain having 2 to 3 ends each ending with a radical polymerizable substituent. The repeating structural unit Y is a monomer unit (1) described in International Publication No. 2018/169036, and in detail, each of the radical polymerizable substituents is substituted on the hydrocarbon chain (L), for example, , and the hydrocarbon chain (L) is bonded to the main chain of the polymer through, for example, a -COO- group. The number of carbon atoms constituting the hydrocarbon chain (L) is, for example, 3 to 5, 3 or 4, or 3. The radical polymerizable substituent is, for example, a (meth)acryloyloxy group.

Alkali-soluble resin A or B of the present invention, for example, a polymer having an epoxy group in the side chain obtained by polymerizing a monomer composition containing an epoxy group-containing (meth)acrylate is reacted with a carboxy group-containing compound to form a side chain having a hydroxyl group. Method (1) of converting and then reacting the hydroxy group with a carboxylic acid anhydride, or a polymer having an epoxy group in the side chain obtained by polymerizing a monomer composition containing an epoxy group-containing (meth)acrylate having an ethylenically unsaturated group and a carboxy group A compound is reacted to convert a side chain having a hydroxyl group and an ethylenically unsaturated group, and a compound having a functional group that reacts with a hydroxyl group such as an isocyanate group is reacted with the hydroxyl group, and further, a hydroxyl group, a thiol group, and an amino group are reacted with the ethylenically unsaturated group It can be synthesized by a method (2) of reacting a compound having a carboxyl group with a functional group that reacts with an ethylenically unsaturated group such as the above.

The alkali-soluble resin A or B may be a homopolymer composed of the repeating structural unit X or X', or a random copolymer or a block copolymer composed of a repeating structural unit different from the repeating structural unit X or X'. , an alternating copolymer, or a periodic copolymer.

In the alkali-soluble resin A or B, the content of the repeating structural unit X or X' is not particularly limited, but from the viewpoint of forming a cured film with excellent development adhesion and resolution even when a thick film is formed, and when a weakly alkaline developer is used It is preferably 5 to 50 mol%, and more preferably 5 to 25 mol%, in all repeating structural units, from the viewpoint of enabling development in a short time.

The weight average molecular weight of the alkali-soluble resin A or B is not particularly limited, but is preferably 5000 to 40000, and more preferably 5000 to 20000 from the viewpoint of sensitivity and developability. The said weight average molecular weight is a value according to polystyrene conversion measured using gel permeation chromatography (GPC), and is a value measured based on JIS7252-4. The weight average molecular weight described in Examples to be described later is also a value obtained according to the description in this section.

The acid value of the alkali-soluble resin A or B is not particularly limited, but is preferably 20 to 120 mgKOH/g, more preferably 20 to 80 mgKOH from the viewpoint of enabling development in a short time even when using a weakly alkaline developer. /g.

The photosensitive resin composition of the present invention contains at least the alkali-soluble resin A and/or B, a polymerizable monomer, and a photopolymerization initiator.

The content ratio of the alkali-soluble resin A and/or B to the total solid content in the photosensitive resin composition (the total amount when used in combination) is not particularly limited, but curing with excellent developing adhesion and resolution even when thickened. From the viewpoint of forming a film and enabling development in a short time even when using a weakly alkaline developer, it is usually about 40 to 90% by mass, preferably 40 to 80% by mass, and more preferably 50 to 70% by mass. am.

The polymerizable monomer is not particularly limited, and examples thereof include nonylphenylcarbitol (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, and 2-ethylhexylcarbitol (meth)acrylate. Monofunctional monomers such as lactate, 2-hydroxyethyl (meth)acrylate, and N-vinylpyrrolidone, or multifunctional aromatic vinyl monomers such as divinylbenzene, diallylphthalate, and diallylbenzenephosphonate ; (di) Ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol di(meth)acrylate , Pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol tetra(meth)acrylate ) polyfunctional (metha) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and tri (meth) acrylate of tris (hydroxyethyl) isocyanurate. ) Polyfunctional monomers, such as acrylate, are mentioned. These polymerizable monomers may be used independently or may use 2 or more types together.

The content of the polymerizable monomer is not particularly limited, but from the viewpoint of sufficiently obtaining the effect of the present invention, it is 30 to 100 parts by mass relative to 100 parts by mass of the alkali-soluble resin A and/or B (when used together, the total is). It is preferably 40 to 80 parts by mass, more preferably 50 to 70 parts by mass.

The photopolymerization initiator is not particularly limited, and examples thereof include benzoin and alkyl ethers thereof such as benzoin, benzoin methyl ether, and benzoin ethyl ether; acetphenones such as acetphenone, 2,2-dimethoxy-2-phenylacetphenone, and 1,1-dichloroacetphenone; anthraquinones such as 2-methylanthraquinone, 2-amylanthraquinone, 2-t-butylanthraquinone, and 1-chloroanthraquinone; thioxanthone such as 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone, and 2-chlorothioxanthone; ketals such as acetphenone dimethyl ketal and benzyl dimethyl ketal; benzophenones such as benzophenone; 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one or 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone -One; Acyl phosphine oxides, xanthones, etc. are mentioned. These photopolymerization initiators may be used alone or in combination of two or more.

The content of the photopolymerization initiator is not particularly limited, but is preferably 0.1 to 5 parts by mass, more preferably 0.2 to 5 parts by mass with respect to 100 parts by mass of the alkali-soluble resin A and/or B (the total is the case when used together). It is 4 parts by mass, more preferably 0.5 to 3 parts by mass.

A photopolymerization initiator may be added to the photosensitive resin composition. Examples of photopolymerization initiator aids include 1,3,5-tris(3-mercaptopropionyloxyethyl)-isocyanurate and 1,3,5-tris(3-mercaptobutyloxyethyl)-iso trifunctional thiol compounds such as cyanurate (Karenz MT (registered trademark) NR1, manufactured by Showa Denko Corporation) and trimethylolpropanetris (3-mercaptopropionate); Tetrafunctional thiol compounds such as pentaerythritol tetrakis(3-mercaptopropionate) and pentaerythritol tetrakis(3-mercaptobutylate) (Karenz MT (registered trademark) PEI manufactured by Showa Denko Co., Ltd.) ; Polyfunctional thiols, such as 6 functional thiol compounds, such as dipentaerythritol hexakis (3-propionate), are mentioned. These photopolymerization initiator aids may be used alone or in combination of two or more.

A thermal polymerization initiator may be added to the photosensitive resin composition. Examples of the thermal polymerization initiator include cumene hydroperoxide, diisopropylbenzene peroxide, di-t-butyl peroxide, lauryl peroxide, benzoyl peroxide, t-butyl peroxyisopropyl carbonate, and t-butyl. organic peroxides such as peroxy-2-ethylhexanoate and t-amylperoxy-2-ethylhexanoate; 2,2'-azobis (isobutylonitrile), 1,1'-azobis (cyclohexanecarbonitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2 Azo compounds, such as '- azobis (2-methylpropionate), etc. are mentioned. These thermal polymerization initiators may be used independently or may use 2 or more types together.

In the photosensitive resin composition, radical polymerizable oligomers such as unsaturated polyester, epoxy acrylate, urethane acrylate, and polyester acrylate; You may add curable resins, such as an epoxy resin.

The photosensitive resin composition may contain a solvent. Examples of the solvent include ethers such as tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, and diethylene glycol dimethyl ether; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; esters such as ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, and 3-methoxybutyl acetate; alcohols such as methanol, ethanol, isopropanol, n-butanol, ethylene glycol monomethyl ether, and propylene glycol monomethyl ether; Aromatic hydrocarbons, such as toluene, xylene, and ethylbenzene; Chloroform, dimethyl sulfoxide, etc. are mentioned. These solvents may be used independently or may use 2 or more types together. In addition, what is necessary is just to set content of a solvent suitably according to the optimum viscosity at the time of using the said composition.

The photosensitive resin composition may contain fillers such as aluminum hydroxide, talc, clay, barium sulfate, dyes, pigments, antifoaming agents, coupling agents, leveling agents, sensitizers, release agents, lubricants, plasticizers, oxidizing agents, etc. You may contain known additives, such as an inhibitor, a ultraviolet absorber, a flame retardant, a polymerization inhibitor, a thickener, and a dispersing agent.

The cured product of the present invention is obtained by curing the photosensitive resin composition. As a method for producing the cured product, for example, after injecting the photosensitive resin composition into a molding mold (resin mold) or coating the photosensitive resin composition on a base material (substrate) or various functional layers to form a desired shape, (For example, a method of curing the photosensitive resin composition by irradiation with ultraviolet rays) is exemplified. Curing conditions are appropriately adjusted according to the photosensitive resin composition to be used.

The cured product is preferably used as a photo spacer, barrier rib material, lens material, interlayer insulating film material, protective film material, optical waveguide material, or flattening film material, and is particularly preferably used as a photo spacer.

The method of forming the photo spacer is not particularly limited, and for example, the photosensitive resin composition is applied to a substrate such as glass or a transparent plastic film, dried to form a coating film, and then formed by photolithography. . In photolithography, for example, a photomask is placed on a coating film, the coating film is photocured by irradiation with ultraviolet rays, an alkaline aqueous solution is sprayed on the coating film after ultraviolet irradiation, the unexposed areas are dissolved and removed, and the remaining exposed areas are washed with water A photo-spacer is formed by developing. After that, you may perform post-baking.

By using the photosensitive resin composition of the present invention, a photo-spacer having a film thickness of 10 μm or more, 20 μm or more, 30 μm or more, or 50 μm or more can be produced with high developing adhesion and high resolution. In addition, a photo-spacer having an aspect ratio of 4.0 or more can be produced by using the photosensitive resin composition of the present invention. In addition, since the photosensitive resin composition of the present invention can be developed in a short time even when using a weakly alkaline developer, photo-spacers can be manufactured with high productivity.

Example

The present invention will be described below with reference to examples, but the present invention is not limited at all by these examples.

[Synthesis Example 1] Synthesis of alkali-soluble resin 1

An alkali-soluble resin 1 comprising the following repeating structural units A and X1 was synthesized according to the following production method.

[Formula 18]

100 g of glycidyl methacrylate and 212 g of propylene glycol monomethyl ether acetate were placed in a glass flask equipped with a heating/cooling/stirring device, a reflux cooling tube and a nitrogen inlet tube. After replacing the gaseous portion in the system with nitrogen, 17 g of 2,2'-azobis(2,4-dimethylvaleronitrile) was added, heated at 80°C, and reacted at the same temperature for 8 hours. 53.2 g of acrylic acid, 1.0 g of triphenylphosphine, 0.02 g of hydroquinone, and 6.0 g of propylene glycol monomethyl ether acetate were further added to the obtained solution, and it was made to react at 100 degreeC for 16 hours. After the reaction, 3.7 g of succinic anhydride and 13.0 g of propylene glycol monomethyl ether acetate were further added to the reaction solution, and it was made to react at 65 degreeC for 6 hours, and the solution containing 45 mass % of alkali-soluble resin 1 was obtained. As a result of measuring the molecular weight by GPC, the weight average molecular weight (Mw) of the alkali-soluble resin 1 was 7,000. In addition, the molecular weight was measured by gel permeation chromatography (product number: HLC-8120 manufactured by Tosoh Corporation, column: G-5000HXL and G-3000HXL double-linked, detector: RI, mobile phase: tetrahydrofuran). Also below, the weight average molecular weight was measured by the same method. In addition, the acid value of alkali-soluble resin 1 was 21 mgKOH/g.

[Synthesis Example 2] Synthesis of alkali-soluble resin 2

A solution containing 45% by mass of alkali-soluble resin 2 was prepared in the same manner as in Synthesis Example 1, except that the amount of succinic anhydride added to the reaction solution was changed to 11.0 g and the amount of propylene glycol monomethyl ether acetate added to 22.0 g. got it As a result of measuring the molecular weight by GPC, the weight average molecular weight (Mw) of alkali-soluble resin 2 was 7,000. Moreover, the acid value of alkali-soluble resin 2 was 54 mgKOH/g.

[Synthesis Example 3] Synthesis of alkali-soluble resin 3

A solution containing 45% by mass of alkali-soluble resin 3 was prepared in the same manner as in Synthesis Example 1, except that the amount of succinic anhydride added to the reaction solution was changed to 18.5 g and the amount of propylene glycol monomethyl ether acetate added to 31.0 g. got it As a result of molecular weight measurement by GPC, the weight average molecular weight (Mw) of alkali-soluble resin 3 was 7,000. In addition, the acid value of alkali-soluble resin 3 was 66 mgKOH/g.

[Synthesis Example 4] Synthesis of alkali-soluble resin 4

Alkali-soluble resin 4 comprising the following repeating structural units A and X1 was synthesized according to the following production method.

[Formula 19]

100 g of glycidyl methacrylate and 150 g of propylene glycol monomethyl ether acetate were placed in a glass flask equipped with a heating/cooling/stirring device, a reflux condenser, and a nitrogen inlet tube. After replacing the gaseous portion in the system with nitrogen, 5.2 g of 2,2'-azobis(2,4-dimethylvaleronitrile) was added, heated at 80°C, and reacted at the same temperature for 8 hours. 53.2 g of acrylic acid, 2.0 g of triphenylphosphine, 0.02 g of hydroquinone, and 1.0 g of propylene glycol monomethyl ether acetate were further added to the obtained solution, and it was made to react at 100 degreeC for 7 hours. After the reaction, 11 g of succinic anhydride and 9.3 g of propylene glycol monomethyl ether acetate were further added to the reaction solution, and it was made to react at 65 degreeC for 6 hours, and the solution containing 52 mass % of alkali-soluble resin 4 was obtained. As a result of measuring the molecular weight by GPC, the weight average molecular weight (Mw) of alkali-soluble resin 4 was 13,000. In addition, the acid value of alkali-soluble resin 4 was 51 mgKOH/g.

[Synthesis Example 5] Synthesis of alkali-soluble resin 5

Alkali-soluble resin 5 comprising the following repeating structural units A, B and X2 was synthesized according to the following production method.

[Formula 20]

100 g of glycidyl methacrylate and 160 g of propylene glycol monomethyl ether acetate were placed in a glass flask equipped with a heating/cooling/stirring device, a reflux condenser, and a nitrogen inlet tube. After replacing the gaseous portion in the system with nitrogen, 7.5 g of 2,2'-azobis(2,4-dimethylvaleronitrile) was added, heated at 80°C, and reacted at the same temperature for 8 hours. 53.2 g of acrylic acid, 0.3 g of triphenylphosphine, and 0.02 g of hydroquinone were further added to the obtained solution, and it was made to react at 100 degreeC for 15 hours. After the reaction, 87 g of 2-isocyanate ethyl methacrylate (manufactured by Showa Denko, Karenz MOI), 0.01 g of hydroquinone, and 0.1 g of N,N'-dimethylbenzylamine were further added to the reaction solution, and 65 It was reacted for 15 hours at °C. After the reaction, 26.0 g of thioglycolic acid, 50 g of propylene glycol monomethyl ether acetate, 0.003 g of hydroquinone, 0.5 g of methoquinone, and 0.5 g of N,N'-dimethylbenzylamine were further added to the reaction solution, and the temperature was 70°C. It was made to react for 20 hours, and the solution containing 50 mass % of alkali-soluble resin 5 was obtained. As a result of measuring the molecular weight by GPC, the weight average molecular weight (Mw) of alkali-soluble resin 5 was 28,000. In addition, the acid value of alkali-soluble resin 5 was 59 mgKOH/g.

[Synthesis Example 6] Synthesis of alkali-soluble resin 6

Alkali-soluble resin 6 containing the following repeating structural units A and X3 was synthesized according to the following production method.

[Formula 21]

100 g of glycidyl methacrylate and 212 g of propylene glycol monomethyl ether acetate were placed in a glass flask equipped with a heating/cooling/stirring device, a reflux cooling pipe, and a nitrogen inlet pipe. After replacing the gaseous portion in the system with nitrogen, 17 g of 2,2'-azobis(2,4-dimethylvaleronitrile) was added, heated at 80°C, and reacted at the same temperature for 8 hours. 53.2 g of acrylic acid, 1.0 g of triphenylphosphine, 0.02 g of hydroquinone, and 6.0 g of propylene glycol monomethyl ether acetate were further added to the obtained solution, and it was made to react at 100 degreeC for 16 hours. After the reaction, 18.2 g of 5-norbornene-2,3-dicarboxylic anhydride and 31.0 g of propylene glycol monomethyl ether acetate were further added to the reaction solution, followed by reaction at 65°C for 19 hours to obtain an acrylic soluble resin 6 A solution containing 45% by mass of was obtained. As a result of measuring the molecular weight by GPC, the weight average molecular weight (Mw) of alkali-soluble resin 6 was 8,000. Moreover, the acid value of alkali-soluble resin 6 was 58 mgKOH/g.

[Synthesis Example 7] Synthesis of alkali-soluble resin 7

To a glass flask equipped with a heating/cooling/stirring device, a reflux cooling pipe, and a nitrogen inlet pipe, 25.0 g of methacrylic acid, 12.8 g of methyl methacrylate, 20.2 g of dicyclopentanyl methacrylate, and propylene glycol monomethyl ether acetate After putting 94.6 g, 6.4 g of 2,2'-azobis(2,4-dimethylvaleronitrile) was added, and it was made to react at 80 degreeC in nitrogen atmosphere for 8 hours. To the obtained solution, 12.3 g of glycidyl methacrylate, 0.2 g of hydroquinone, and 2.5 g of propylene glycol monomethyl ether acetate were further added, followed by reaction at 100°C for 19 hours, containing 45% by mass of alkali-soluble resin 7. A solution was obtained. As a result of measuring the molecular weight by GPC, the weight average molecular weight (Mw) of alkali-soluble resin 7 was 11,800. Moreover, the acid value of alkali-soluble resin 7 was 107 mgKOH/g.

[Synthesis Example 8] Synthesis of alkali-soluble resin 8

To a glass flask equipped with a heating cooling/stirring device, a reflux condenser, and a nitrogen inlet tube, 25.0 g of methacrylic acid, 22.6 g of methyl methacrylate, 18.4 g of butyl methacrylate, and 99.0 g of propylene glycol monomethyl ether acetate were added. After adding, 5.6 g of 2,2'-azobis(2,4-dimethylvaleronitrile) was added and reacted at 80°C for 8 hours under a nitrogen atmosphere. To the obtained solution, 18.4 g of glycidyl methacrylate, 0.2 g of hydroquinone, and 4.3 g of propylene glycol monomethyl ether acetate were further added, followed by reaction at 100°C for 19 hours, containing 45% by mass of alkali-soluble resin 8. A solution was obtained. As a result of measuring the molecular weight by GPC, the weight average molecular weight (Mw) of alkali-soluble resin 8 was 10,800. Moreover, the acid value of alkali-soluble resin 8 was 106 mgKOH/g.

[Synthesis Example 9] Synthesis of alkali-soluble resin 9

100 g of glycidyl methacrylate and 212 g of propylene glycol monomethyl ether acetate were placed in a glass flask equipped with a heating/cooling/stirring device, a reflux cooling pipe, and a nitrogen inlet pipe. After replacing the gaseous portion in the system with nitrogen, 17 g of 2,2'-azobis(2,4-dimethylvaleronitrile) was added, heated at 80°C, and reacted at the same temperature for 8 hours. 53.2 g of acrylic acid, 1.0 g of triphenylphosphine, 0.02 g of hydroquinone, and 6.0 g of propylene glycol monomethyl ether acetate were further added to the obtained solution, and it was made to react at 100 degreeC for 12 hours, and 44 mass of alkali-soluble resin 9 were added A solution containing % was obtained. As a result of measuring the molecular weight by GPC, the weight average molecular weight (Mw) of alkali-soluble resin 9 was 9,000. In addition, the acid value of alkali-soluble resin 9 was 12 mgKOH/g.

[Synthesis Example 10] Synthesis of alkali-soluble resin 10

Synthesis Example 6, except that 14.2 g of trimellitic anhydride was added instead of 18.2 g of 5-norbornene-2,3-dicarboxylic acid anhydride and the addition amount of propylene glycol monomethyl ether acetate was changed from 31.0 g to 26.2 g. A solution containing 45% by mass of alkali-soluble resin 10 was obtained by the same manufacturing method as above. As a result of measuring the molecular weight by GPC, the weight average molecular weight (Mw) of alkali-soluble resin 10 was 16,000. In addition, the acid value of alkali-soluble resin 10 was 62 mgKOH/g.

Examples 1 to 7, and Comparative Examples 1 to 3

[Preparation of photosensitive resin composition]

100 parts by mass of the above solution containing 45 mass% of alkali-soluble resin 1, 60 parts by mass of dipentaerythritol hexaacrylate (manufactured by Nippon Chemical Co., Ltd., KAYARAD DPHA), 1.6 parts by mass of photopolymerization initiator (manufactured by LAMBSON, SPEEDCURE TPO), 1.0 parts by mass of a photopolymerization initiator (BASF Japan Co., Ltd., Irgacure OXE01) and 0.2 parts by mass of a surfactant (BYK-307, manufactured by BYK) were mixed to prepare a photosensitive resin composition having a solid content of 50% in the composition (Example 1). Instead of 100 parts by mass of the solution containing 45% by mass of alkali-soluble resin 1, 100 parts by mass of each solution containing 2 to 10 alkali-soluble resins by mass was used, in the same manner as above, so that the solid content in the composition was reduced. A 50% photosensitive resin composition was prepared (Examples 2 to 7 and Comparative Examples 1 to 3).

[Evaluation of developability]

The photosensitive resin compositions prepared in Examples 1 to 7 and Comparative Examples 1 to 3 were respectively coated on each glass substrate of 10 cmХ10 cm square using a spin coater to form a coating film with a film thickness of 30 μm, and the coating film was heated at 90 ° C. The solvent was completely removed by heating on the plate for 2 minutes. Thereafter, the obtained coating film was subjected to alkali development using a 0.3% Na ₂ CO ₃ aqueous solution, and developability was evaluated by setting the time for the coating film to be dissolved and removed as the shortest developing time. It can be said that the developability is excellent, so that this value is small. Ranks were classified according to the following criteria.

A: The shortest development time is within 60 seconds

B: The shortest developing time exceeds 60 seconds and is within 80 seconds

C: The shortest developing time exceeds 80 seconds and is within 100 seconds

F: The shortest development time exceeds 100 seconds

[Production of photo spacer]

Each photosensitive resin composition prepared in Examples 1 to 7 and Comparative Examples 1 to 3 was formed on each glass substrate of 10cmХ10cm square by adjusting the rotation speed of the spin coater using a spin coater, and the height of the photo spacer was 30 μm. , and each coating film was heated on a hot plate at 100° C. for 2 minutes to completely remove the solvent. Thereafter, each obtained coating film was irradiated with light from an ultra-high pressure mercury lamp at 100 mJ/cm 2 through a mask for forming a photo spacer having openings every 1 μm from 4 to 30 μm ⁱⁿ diameter, 100 per 1 cm ² (in terms of i-rays). with an illuminance of 21 mW/cm ² ). In addition, the exposure was performed at an interval (exposure gap) between the mask and the substrate of 100 µm. Then, alkali development was performed using a 0.3% Na ₂ CO ₃ aqueous solution. The developing time was 1.5 times the shortest developing time measured by the method described above. After washing with water, post-baking was performed at 230°C for 30 minutes to form a photo spacer.

[Evaluation of development adhesion]

Among the photo-spacers formed by the above-described method, the line width of the minimum pattern formed without being removed by development was evaluated as developing adhesion. It can be said that the developing adhesiveness is excellent, so that this value is small. Ranks were classified according to the following criteria.

A: The minimum pattern is less than 15 μm

B: The minimum pattern is 15 μm or more and less than 20 μm

C: The minimum pattern is 20 μm or more

F: Unable to develop

[Table 1]

From the results of Table 1, when a weak alkali developer was used in the formation of a thick film pattern having a pattern height of about 30 μm, the photosensitive resin compositions of Examples 1 to 7 were developed in a shorter time than the photosensitive resin compositions of Comparative Examples 1 to 3. , and it is found that a cured film having excellent developing adhesion can be formed.

The alkali-soluble resin of the present invention and the photosensitive resin composition containing the alkali-soluble resin are preferably used as raw materials for photo spacers, barrier rib materials, lens materials, interlayer insulating film materials, protective film materials, optical waveguide materials, or planarization film materials. .

Claims (14)

An alkali-soluble resin containing at least one repeating structural unit X represented by the following general formula (1):
[Formula 1]

(Wherein, R ¹ is hydrogen or a methyl group, R ² is a linking group having 1 or more carbon atoms, R ³ is an organic group represented by the following general formula (2) bonded to a carbon atom of the linking group, and R ⁴ is the linking group It is a hydroxy group or an organic group bonded to the carbon atom of
[Formula 2]

(In the formula, R ⁵ is an organic group having 3 to 8 carbon atoms and containing a hetero atom, or an organic group having 2 to 7 carbon atoms and a carboxy group.) Containing at least one repeating structural unit X' represented by the following general formula (1'), provided that it does not contain a repeating structural unit having branched side chains having 2 to 3 terminals each ending with a radical polymerizable substituent. , Alkali-soluble resin:
[Formula 3]

(Wherein, R ¹ is hydrogen or a methyl group, R ² is a linking group having 1 or more carbon atoms, R ^3' is an organic group represented by the following general formula (2') bonded to a carbon atom of the linking group, and R ⁴ is It is a hydroxy group or an organic group bonded to the carbon atom of the linking group.)
[Formula 4]

(Wherein, R ^5' is a hydrocarbon group having 2 to 7 carbon atoms as a parent, an organic group having 3 to 8 carbon atoms and containing a hetero atom, or an organic group having 2 to 7 carbon atoms and having a carboxy group) device.) According to claim 1 or 2,
The linking group of R ² is a hydrocarbon group having 1 to 10 carbon atoms as a parent, or an organic group having 1 to 10 carbon atoms as a parent and containing a hetero atom, alkali-soluble resin. According to any one of claims 1 to 3,
The organic group of R ⁴ is at least one functional group selected from the group consisting of an acryloyloxy group, a methacryloyloxy group, an acyloxy group, an amideoxy group, an alkoxy group, an aryloxy group, an amino group, and a nitrogen-containing heterocycle. Alkali-soluble resin which is an organic group containing. According to claim 1 or 2,
The linking group of R ² is a hydrocarbon group having 1 to 7 carbon atoms as a parent, or an organic group having 1 to 7 carbon atoms as a parent and containing a hetero atom;
The R ⁴ is a hydroxy group, an acryloyloxy group, or a methacryloyloxy group bonded to a carbon atom of the linking group of the R ² , alkali-soluble resin. According to claim 1,
The linking group of R ² is a hydrocarbon group having 1 to 7 carbon atoms as a parent, or an organic group having 1 to 7 carbon atoms as a parent and containing a hetero atom;
Said R ⁵ is an organic group represented by the following general formula (3),
Alkali-soluble resin, wherein R ⁴ is a hydroxyl group bonded to a carbon atom of the linking group of R ² , an acryloyloxy group, a methacryloyloxy group, or an organic group represented by the following general formula (4):
[Formula 5]

(In the formula, R ⁶ and R ⁷ are each independently a hydrocarbon group having 1 to 6 carbon atoms, and the total carbon atoms of the parent of R ⁶ and R ⁷ are 3 to 8.)
[Formula 6]

(In the formula, R ⁸ is hydrogen or a methyl group, R ⁹ is a hydrocarbon group having 1 to 5 carbon atoms as a parent, or an organic group having 1 to 5 carbon atoms as a parent and containing a hetero atom.) According to claim 2,
The linking group of R ² is a parent hydrocarbon group having 1 to 7 carbon atoms or an organic group having 1 to 7 carbon atoms and containing a hetero atom;
Said R5 ^' is an organic group represented by the following general formula (3),
Alkali-soluble resin, wherein R ⁴ is a hydroxyl group bonded to a carbon atom of the linking group of R ² , an acryloyloxy group, a methacryloyloxy group, or an organic group represented by the following general formula (4):
[Formula 7]

(In the formula, R ⁶ and R ⁷ are each independently a hydrocarbon group having 1 to 6 carbon atoms, and the total carbon atoms of the parent of R ⁶ and R ⁷ are 3 to 8.)
[Formula 8]

(In the formula, R ⁸ is hydrogen or a methyl group, R ⁹ is a hydrocarbon group having 1 to 5 carbon atoms as a parent, or an organic group having 1 to 5 carbon atoms as a parent and containing a hetero atom.) According to any one of claims 1 to 7,
The content of the repeating structural unit X or X' is 5 to 50 mol% of the total repeating structural unit, alkali-soluble resin. According to any one of claims 1 to 8,
The alkali-soluble resin has an acid value of 20 to 120 mgKOH/g, an alkali-soluble resin. According to any one of claims 1 to 9,
The alkali-soluble resin has a weight average molecular weight of 5000 to 40000, alkali-soluble resin. A photosensitive resin composition containing at least the alkali-soluble resin according to any one of claims 1 to 10, a polymerizable monomer, and a photopolymerization initiator. A cured product obtained from the photosensitive resin composition according to claim 11. According to claim 12,
The cured product is a photo spacer, a partition material, a lens material, an interlayer insulating film material, a protective film material, an optical waveguide material, or a flattening film material. An image display device comprising the cured product according to claim 12 or 13.