JP7844843B2 - Polymers, polymer solutions, photosensitive resin compositions, and cured products - Google Patents

Description

This invention relates to a polymer, a polymer solution containing the polymer, a photosensitive resin composition containing the polymer solution, and a cured product of the photosensitive resin composition.

Liquid crystal display devices and solid-state image sensors typically incorporate color filters and black matrices. These color filters and black matrices have structures such as colored patterns and protective films formed on a substrate. Of these structures, the most common method for forming colored patterns and protective films is photolithography using a photosensitive resin composition. Various studies have been conducted on photosensitive resin compositions. For example, Patent Document 1 describes a photosensitive resin composition comprising an alkali-soluble resin having at least one acidic group and two or more distinct polymerizable unsaturated groups in its side chain, a polymerizable compound, and a photopolymerization initiator. Furthermore, the examples in Patent Document 1 describe the synthesis of a methacrylic acid/allyl methacrylate/glycidyl adduct as the alkali-soluble resin, and the preparation of a photosensitive resin composition using this adduct.

International Publication No. 2012/147706

Photosensitive resin compositions used to form color filters and black matrices utilize resins that undergo polymerization and hardening upon exposure to light. Color filters and black matrices are produced by patterning the photosensitive resin composition through exposure and development, followed by hardening. While "high sensitivity" may seem like a common challenge in photosensitive resin compositions, the increasing complexity and widespread use of display and imaging devices necessitates even higher levels of sensitivity. Higher sensitivity in a photosensitive resin composition reduces the exposure time, improving productivity. Furthermore, photosensitive resin compositions are required to exhibit excellent processability in development processes using alkaline developers. Additionally, the hardened product of the photosensitive resin composition is required to possess high transparency.

The present inventors have discovered that by improving the polymer used in the photosensitive resin composition and the formulation of the composition, it is possible to obtain a cured resin product with good sensitivity, high alkali solubility, and reduced yellowing, leading to the present invention.

According to the present invention, a polymer having a structure represented by formula (P) is provided.

(In equation (P),
m is 0,
n is an integer between 1 and 6.
p is greater than 0, q is greater than 0, and r is 0.
p represents the molar content of A, q represents the molar content of B, and p + q = 1.
X is hydrogen,
Y is an organic group having a thioether group, which is a 1-6 valent organic group derived from at least one selected from two or more thiol group-containing compounds represented by formula (s-1) to (s-21), and the organic group having the thioether group is bonded to the structural unit in [ ]n via the thioether group (*-S-* (* is a bond)) derived from the thiol group-containing compound,
A represents a structural unit expressed by formula (IN),
B includes at least one structural unit selected from the structural units represented by formula (5), formula (6), formula (8), and formula (9) ,
The structural units A and B are arranged randomly or alternately .

(In formula (IN), ^R1 and ^R2 are each independently a hydrogen atom or an organic group having 1 to 30 carbon atoms.)

(In equations (5), (6), (8), and (9),
R ^p represents a group containing two or more (meth)acryloyl groups,
R ^s represents a group containing one (meth)acryloyl group,
Z is a group containing one or more (meth)acryloyl groups,
Q is a hydrogen atom, or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms.
X represents an oxygen atom, a substituted or unsubstituted alkylene group with 1 to 4 carbon atoms,
If Q is the alkyl group and X is the alkylene group, Q and X may condense to form a cyclic group.

Furthermore, according to the present invention, a polymer solution containing the above-mentioned polymer is provided.

Furthermore, the present invention provides a photosensitive resin composition comprising the above-mentioned polymer solution and a photopolymerization initiator.

Furthermore, according to the present invention, a cured product of the above-mentioned photosensitive resin composition is provided.

According to the present invention, a polymer is provided as a resin material for use in a photosensitive resin composition that has good sensitivity, high alkali solubility, and therefore excellent developability, as well as reduced yellowing and therefore high heat-resistant discoloration.

This is a schematic diagram (cross-sectional view) illustrating an example of the structure of a liquid crystal display device and/or a solid-state image sensor.

The embodiments of the present invention will be described below with reference to the drawings. In all drawings, similar components are denoted by the same reference numerals, and their descriptions are omitted where appropriate. Furthermore, all drawings are for illustrative purposes only. The shapes and dimensional ratios of the components in the drawings do not necessarily correspond to actual articles. In this specification, the notation "a to b" in descriptions of numerical ranges means "a or more and b or less" unless otherwise specified. For example, "5 to 90%" means "5% or more and 90% or less."

In this specification, when a group (atomic group) is not specified as substituted or unsubstituted, it encompasses both unsubstituted and substituted groups. For example, "alkyl group" includes not only unsubstituted alkyl groups but also substituted alkyl groups.

In this specification, the term "(meth)acrylic" refers to a concept that encompasses both acrylic and methacrylic. The same applies to similar terms such as "(meth)acrylate."
In particular, the term "(meth)acryloyl group" in this specification refers to a concept that encompasses both the acryloyl group represented by -C(=O)-CH= _CH2 and the methacryloyl group represented by -C(=O)-C( _CH3 )= _CH2 .

[Polymer P]
(First embodiment)
The polymer of this embodiment (hereinafter referred to as "polymer P") has a structure represented by the following general formula (P). Polymer P has a structure in which a polymer chain, typically composed of structural units A and B, is bonded to a 2- to 6-valent organic group having 1 to 30 carbon atoms, derived from a thiol group-containing compound with two or more functionalities represented as "Y" in the formula.

In general formula (P),
m is preferably 0 or 1, and more preferably 0.
n is an integer between 1 and 6, preferably between 3 and 6.
However, n+m is between 2 and 6, preferably between 3 and 6.
p is greater than 0, preferably between 0.25 and 0.75.
q is greater than 0, preferably between 0.25 and 0.75.
r is 0 or greater, preferably 0 to 0.5, more preferably 0 to 0.3, and particularly preferably 0 to 0.1.
p, q, or r may be the same or different for each of the n structural units within the brackets [ ].
X is either hydrogen or an organic group having between 1 and 30 carbon atoms.
Y is a divalent to hexavalent organic group (i) having 1 to 30 carbon atoms derived from a thiol group-containing compound with two or more functionalities, and is bonded to the structural units in [ ]n and [ ]m via a thioether group derived from the thiol group.
A represents a structural unit expressed by formula (IN).
B includes at least one structural unit selected from the structural units represented by formula (1), the structural units represented by formula (2), and the structural units represented by formula (3).
C contains a divalent structural unit derived from copolymerizable compounds having a double bond.
Multiple instances of A, B, or C may be identical or different.
In general formula (P), the order in which A, B, and C are combined is not particularly limited, and any of A, B, and C may be combined with Y.
D represents a structure different from the structure in [ ]n, and D may include any of A, B, or C.

In formula (IN), ^R1 and ^R2 are each independently a hydrogen atom or an organic group having 1 to 30 carbon atoms.

In formula (1), ^Rp represents a group containing two or more (meth)acryloyl groups. Preferably, ^Rp is a group containing 2 to 9 (meth)acryloyl groups, and more preferably, a group containing 3 to 6 (meth)acryloyl groups. By optimizing the number of (meth)acryloyl groups, the sensitivity of the resulting polymer P in photolithography can be increased. Furthermore, a higher balance between sensitivity and developability can be achieved, and heat resistance can be improved.

In formula (2), R ^s represents a group containing one (meth)acryloyl group.

In equation (3),
Z is a group containing one or more (meth)acryloyl groups.
Q is a hydrogen atom, or a substituted or unsubstituted C1-C6 alkyl group. Examples of this alkyl group include a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, and hexyl group. Examples of substituents on the substituted C1-C6 alkyl group include halogen atoms, hydroxyl groups, carboxyl groups, amino groups, cyano groups, and mercapto groups.
X represents an oxygen atom or a substituted or unsubstituted alkylene group having 1 to 4 carbon atoms. Examples of alkylene groups constituting X include methylene, ethylene, propylene, and butylene groups. Examples of substituents on a substituted alkylene group having 1 to 4 carbon atoms include halogen atoms, hydroxyl groups, carboxyl groups, amino groups, cyano groups, and mercapto groups.
When Q is the alkyl group and X is the alkylene group, the alkyl group of Q and any carbon atom of the alkylene group of X may bond to form a ring. Examples of ring structures include a cyclopropane ring, cyclobutane ring, cyclopentane ring, cyclohexane ring, decalin ring, benzene ring, naphthalene ring, and the like.
In formula (3), the embodiment in which X is an alkylene having 1 to 4 carbon atoms and Z is a (meth)acryloyloxy group, or the embodiment in which X is an oxygen atom and Z is a (meth)acryloyl group, is preferably used.

The polymer P of this embodiment has a structure in which a polymer chain, typically composed of structural units A and B, is bonded to a 2- to 6-valent organic group having 1 to 30 carbon atoms, derived from a thiol group-containing compound with two or more functionalities represented as "Y" in formula (P). Because polymer P has a thioether group, it exhibits excellent sensitivity in photolithography and higher alkali solubility, thus providing a resin cured product with superior developability.

The polymer P of this embodiment also includes, as structural unit B, at least one of the structural units represented by general formula (1), general formula (2), and general formula (3). In other words, polymer P comprises a structural unit having at least one (meth)acryloyl group as an essential component. As a result, the photosensitive resin composition containing polymer P exhibits excellent sensitivity when subjected to photolithography. This is thought to be because the (meth)acryloyl groups contained in the structural units represented by general formulas (1) to (3) promote the curing reaction (polymerization reaction).

Furthermore, polymer P contains a structural unit A, which is derived from indene and represented by the general formula (IN). This structural unit (IN) is chemically robust. Therefore, polymer P containing this structural unit exhibits minimal weight loss and stability when subjected to heat treatment. Thus, photosensitive resin compositions containing polymer P can be suitably used to manufacture films and filters for use in liquid crystal display devices and solid-state image sensors where heat resistance is required.

In one embodiment, polymer P may include, as structural unit B, the structural unit represented by formula (4) in addition to the structural units represented by formulas (1) to (3). By including the structural unit represented by formula (4), polymer P has high alkali solubility. As a result, a photosensitive resin composition containing such polymer P exhibits excellent developability when subjected to photolithography processing using an alkaline aqueous solution as the developer.

In one embodiment, polymer P may contain structural units C derived from monomers polymerizable with respect to indene and maleic anhydride. Structural units C are, for example, substituted or unsubstituted norbornene, styrene, maleimide, or norbornadiene. Substituents that these monomers may have include alkyl groups and aryl groups. More specifically, substituted maleimides include cyclohexylmaleimide and phenylmaleimide. Substituted styrenes include methylstyrene and vinyltoluene.

Preferably, structural unit C includes the structural unit represented by general formula (11) (a divalent structural unit derived from substituted or unsubstituted norbornene), the structural unit represented by general formula (12) (a divalent structural unit derived from substituted or unsubstituted maleimide), the structural unit represented by general formula (13) (a divalent structural unit derived from substituted or unsubstituted styrene), or the structural unit represented by general formula (14) (a divalent structural unit derived from substituted or unsubstituted norbornadiene).

In general formula (11), ^R1 to ^R4 each independently represent a hydrogen atom, an alkyl group, or an aryl group, and _a1 is 0 or 1. In general formula (12), ^R3 represents a hydrogen atom, an alkyl group, or an aryl group. In general formula (13), ^R4 to ^R6 each independently represent a hydrogen atom, an alkyl group, or an aryl group. In general formula (14), ^R7 to ^R10 each independently represent a hydrogen atom, a hydroxyl group, or an organic group having 1 to 30 carbon atoms.

In the structural unit represented by the general formula (IN) that constitutes polymer P, examples of C1 to C30 organic groups that can constitute ^R1 and ^R2 include substituted or unsubstituted, linear or branched C1 to C30 alkyl groups, more specifically, alkyl groups, alkenyl groups, alkynyl groups, alkylidene groups, aryl groups, aralkyl groups, alkalil groups, cycloalkyl groups, alkoxy groups, heterocyclic groups, carboxyl groups, and the like.

Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, and decyl groups.

Examples of alkenyl groups include allyl groups, pentenyl groups, and vinyl groups.
Examples of alkynyl groups include the ethynyl group.
Examples of alkylidene groups include methylidene groups and ethylidene groups.
Examples of aryl groups include tolyl, xylyl, phenyl, naphthyl, and anthracenyl groups.

Examples of aralkyl groups include the benzyl group and the phenethyl group.
Examples of alkalyl groups include tolyl groups and xylyl groups.
Examples of cycloalkyl groups include adamantyl, cyclopentyl, cyclohexyl, and cyclooctyl groups.
Examples of alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy, tert-butoxy, n-pentyloxy, neopentyloxy, and n-hexyloxy groups.
Examples of heterocyclic groups include epoxy groups and oxetanyl groups.

In the structural unit represented by the general formula (IN), ^R1 and ^R2 are preferably hydrogen or alkyl groups, and more preferably hydrogen.
Furthermore, the hydrogen atoms in the organic groups ^R1 and ^R2 , having 1 to 30 carbon atoms, may be substituted with any atomic group. For example, they may be substituted with fluorine atoms, hydroxyl groups, carboxyl groups, etc. More specifically, alkyl fluorides may be selected as the organic groups ^R1 and ^R2 , having 1 to 30 carbon atoms.

The proportion of structural units represented by the general formula (IN) in the total structural units of polymer P is preferably 10 to 90 mol%, more preferably 30 to 70 mol%, and even more preferably 40 to 60 mol%.

In a structural unit represented by general formula (1) that can constitute polymer P, ^Rp is a group containing two or more (meth)acryloyl groups, preferably a group containing 2 to 6 (meth)acryloyl groups, and more preferably a group containing 3 to 5 (meth)acryloyl groups. By optimizing the number of (meth)acryloyl groups contained in ^Rp , the sensitivity of polymer P in exposure treatment can be further increased. Furthermore, it becomes easier to achieve a higher level of compatibility between the sensitivity and alkali solubility of polymer P. In addition, the heat resistance of polymer P can be improved.

In general formula (1), R ^p is preferably a group represented by general formula (1b), a group represented by general formula (1c), or a group represented by general formula (1d), and includes at least one selected from these. Having such a group tends to make it easier to obtain the various effects described above.

In formula (1b),
k is 2 or 3,
R is a hydrogen atom or a methyl group, and multiple Rs may be the same or different.
^X1 is a single bond, an alkylene group having 1 to 6 carbon atoms, or a group represented by -Z-X- (where Z is -O- or -OCO-, and X is an alkylene group having 1 to 6 carbon atoms). Multiple ^X1 groups may be identical or different.
^X1 ' is a single bond, an alkylene group having 1 to 6 carbon atoms, or a group represented by -X'-Z'- (where X' is an alkylene group having 1 to 6 carbon atoms, and Z' is -O- or -COO-),
^X2 is a k+1 valent organic group with 1 to 12 carbon atoms.
For R, a hydrogen atom is preferred due to further improvements in sensitivity (ease of polymerization), etc.
k can be either 2 or 3, but 3 is preferred from the standpoint of ease of obtaining raw materials and further improvement of sensitivity.

If ^X1 is an alkylene group having 1 to 6 carbon atoms, the alkylene group may be linear or branched.
When ^X1 is an alkylene group having 1 to 6 carbon atoms, ^X1 is preferably a linear alkylene group, more preferably a linear alkylene group having 1 to 3 carbon atoms, and even more preferably a _-CH2- (methylene group).

When ^X1 is a group represented by -Z-X- (where Z is -O- or -OCO- and X is an alkylene group having 1 to 6 carbon atoms), the alkylene group of X having 1 to 6 carbon atoms may be linear or branched.
The alkylene group of X having 1 to 6 carbon atoms is preferably a linear alkylene group, more preferably a linear alkylene group having 1 to 3 carbon atoms, and even more preferably _-CH2 - _CH2- (ethylene group) or _-CH2 -CH( _CH3 )-.

When ^X1 ' is an alkylene group having 1 to 6 carbon atoms, the specific embodiment is the same as for ^X1 .
If ^X1 ' is a base represented by -X'-Z'-, the specific form of X' is the same as that of X described above.

As for the k+1 valent organic group ^X2 having 1 to 12 carbon atoms, any group obtained by removing k+1 hydrogen atoms from any organic compound can be cited. Here, "any organic compound" refers to, for example, an organic compound with a molecular weight of 300 or less, preferably 200 or less, and more preferably 100 or less.
^X2 is, for example, a group obtained by removing k+1 hydrogen atoms from a linear or branched hydrocarbon having 1 to 12 carbon atoms (preferably 1 to 6 carbon atoms). More preferably, it is a group obtained by removing k+1 hydrogen atoms from a linear hydrocarbon having 1 to 3 carbon atoms. Note that the hydrocarbon here may contain oxygen atoms (e.g., ether bonds or hydroxyl groups). Furthermore, the hydrocarbon is preferably a saturated hydrocarbon.
In another embodiment, ^X2 may be a group containing a cyclic structure. Examples of groups containing a cyclic structure include groups containing an alicyclic structure and groups containing a heterocyclic structure (for example, an isocyanuric acid structure).

In formula (1c),
k, R, ^X1 , and ^X2 are equivalent to R, k, ^X1 , and ^X2 in equation (1b), respectively, and the multiple Rs may be the same or different from each other, and the multiple ^X1s may be the same or different from each other.
^X3 is a divalent organic group having 1 to 6 carbon atoms.
^X4 and ^X5 are each independently a single bond or a divalent organic group having 1 to 6 carbon atoms.
^X6 is a divalent organic group having 1 to 6 carbon atoms.

The specific embodiments and preferred embodiments of R, k, ^X1 , and ^X2 are the same as those described in general formula (1b).
Examples of divalent organic groups having 1 to 6 carbon atoms in ^X3 and ^X6 include groups obtained by removing two hydrogen atoms from a linear or branched hydrocarbon having 1 to 6 carbon atoms. The hydrocarbon here may also contain oxygen atoms (e.g., ether bonds or hydroxyl groups). Furthermore, the hydrocarbon is preferably a saturated hydrocarbon.
Examples of divalent organic groups having 1 to 6 carbon atoms in ^X4 and ^X5 include linear or branched alkylene groups. The linear or branched alkylene group preferably has 1 to 3 carbon atoms.

In formula (1d), n is an integer between 2 and 5, preferably 2 or 3.
The specific and preferred forms of R are the same as those described in general formula (1b).

When polymer P contains structural units represented by general formula (1), the proportion of structural units represented by general formula (1) in the total structural units of polymer P is preferably 3 to 40 mol%, more preferably 3 to 30 mol%.

In the structural unit represented by general formula (2) that can constitute polymer P, R ^S is a group containing only one (meth)acryloyl group. In particular, in the design of ordinary photosensitive resin compositions, when curability is increased in order to increase sensitivity, curing tends to progress too much and developability tends to deteriorate, while when developability is improved, curing tends to be insufficient. Therefore, it is preferable that polymer P contains either or both of the structural units represented by general formula (1) and the structural units represented by general formula (2), thereby achieving a good balance between sensitivity and developability.

R ^S is a group represented by, for example, the following formula (2a).

In formula (2a), X ¹⁰ is a divalent organic group, and R is a hydrogen atom or a methyl group.
The total number of carbon atoms in X ¹⁰ is preferably 1 to 30, more preferably 1 to 20, and even more preferably 1 to 10.
In formula (2a), X ¹⁰ is a divalent organic group, and R is a hydrogen atom or a methyl group.
The total number of carbon atoms in X ¹⁰ is preferably 1 to 30, more preferably 1 to 20, and even more preferably 1 to 10.
A preferred divalent organic group of X ¹⁰ is, for example, an alkylene group. Some of the _-CH2- in this alkylene group may be ether groups (-O-). The alkylene group may be linear or branched, but linear is more preferred.

The divalent organic group of X ¹⁰ is more preferably a linear alkylene group having a total of 3 to 6 carbon atoms. By appropriately selecting the number of carbon atoms in X ¹⁰ (the chain length of X ¹⁰ ), the structural unit represented by formula (2) becomes more readily involved in the crosslinking reaction, thereby increasing sensitivity.

The divalent organic group of X ¹⁰ (e.g., an alkylene group) may be substituted with any substituent. Examples of substituents include alkyl groups, aryl groups, alkoxy groups, and aryloxy groups.
Furthermore, the divalent organic group of X ¹⁰ may be any group other than an alkylene group. For example, it may be a divalent group formed by linking one or more groups selected from alkylene groups, cycloalkylene groups, arylene groups, ether groups, carbonyl groups, carboxyl groups, etc.

When polymer P contains structural units represented by general formula (2), the proportion of structural units represented by general formula (2) in the total structural units of polymer P is preferably 5 to 40 mol%, more preferably 10 to 30 mol%.

Furthermore, when polymer P contains both structural units represented by general formula (1) and structural units represented by general formula (2), the total content of structural units represented by general formula (1) and general formula (2) in polymer P is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, and even more preferably 10 to 40 mol%, based on the total structural units constituting polymer P.

When polymer P contains structural units represented by general formula (3), the proportion of structural units represented by general formula (3) in the total structural units of polymer P is preferably 0.25 to 17 mol%, more preferably 0.5 to 12 mol%.

In general formula (P), X is hydrogen or an organic group having 1 to 30 carbon atoms. The organic group having 1 to 30 carbon atoms is the same as the organic group having 1 to 30 carbon atoms that constitutes ^R1 and ^R2 in formula (IN) above.

In general formula (P), Y is a divalent to hexavalent organic group (i) having 1 to 30 carbon atoms derived from a thiol group-containing compound with two or more functionalities. In this embodiment, the number of functional groups is the number of thiol groups. That is, the thiol group-containing compound contains two or more thiol groups, and the organic group (i) is bonded to the structural units in [ ]n and [ ]m via 1 to 6 thioether groups derived from the thiol group. The organic group (i) may also have thiol groups that are not involved in bonding to the structural units in [ ]n and [ ]m, and polymer P can be obtained as a mixture of resins with n+m numbers (number of bonds) of 2 to 6.
The organic group (i) having 1 to 30 carbon atoms is bifunctional or more, preferably trifunctional or more. The upper limit is not particularly limited, but is 6-functional or less.
From the viewpoint of the effects of the present invention, the valency of the organic group (i) having 1 to 30 carbon atoms is 2 to 6, preferably 2 to 6.

The 2-6 valent organic group (i) having 1 to 30 carbon atoms may contain one or more atoms selected from O, N, S, P, and Si. Examples of the 2-6 valent organic group (i) having 1 to 30 carbon atoms include alkyl groups, alkenyl groups, alkynyl groups, alkylidene groups, aryl groups, aralkyl groups, alkalil groups, cycloalkyl groups, alkoxy groups, and heterocyclic groups having 2 to 6 thioether groups (*-S-* (* represents a bond)).

Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, and decyl groups. Examples of alkenyl groups include allyl, pentenyl, and vinyl groups.

An example of an alkynyl group is the ethynyl group.
Examples of alkylidene groups include methylidene and ethylidene. Examples of aryl groups include tolyl, xylyl, phenyl, naphthyl, and anthracenyl groups.
Examples of aralkyl groups include the benzyl group and the phenethyl group.
Examples of alkalyl groups include tolyl groups and xylyl groups.

Examples of cycloalkyl groups include adamantyl, cyclopentyl, cyclohexyl, and cyclooctyl groups.
Examples of alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, s-butoxy, isobutoxy, t-butoxy, n-pentyloxy, neopentyloxy, and n-hexyloxy groups.
Examples of heterocyclic groups include epoxy groups and oxetanyl groups.

Polymer P may contain at least one structural unit selected from the structural unit represented by formula (5), formula (6), formula (8), and formula (9), as a structural unit containing one or two of the above general formulas (1), (2), and (3). By containing such structural units, polymer P may have high alkali solubility. In formulas (5), (6), (8), and (9), R ^p , R ^s , Q, X, and Z are the same as those in formulas (1) to (3).

When polymer P contains structural units represented by general formula (5), the proportion of structural units represented by general formula (5) in the total structural units of polymer P is preferably 0.5 to 25 mol%, more preferably 1 to 18 mol%.

When polymer P contains structural units represented by general formula (6), the proportion of structural units represented by general formula (6) in the total structural units of polymer P is preferably 3 to 35 mol%, more preferably 5 to 25 mol%.

When polymer P contains structural units represented by general formula (8), the proportion of structural units represented by general formula (8) in the total structural units of polymer P is preferably 0.25 to 17 mol%, more preferably 0.5 to 12 mol%.

When polymer P contains structural units represented by general formula (9), the proportion of structural units represented by general formula (9) in the total structural units of polymer P is preferably 0.5 to 35 mol%, more preferably 2 to 25 mol%.

In one embodiment, polymer P may contain structural units represented by formula (10). By containing structural units represented by formula (10), polymer P exhibits excellent alkali solubility. As a result, the photosensitive resin composition containing polymer P exhibits an excellent balance of sensitivity and developability even when subjected to photolithography using a strongly basic developer.

When polymer P contains structural units represented by general formula (10), the proportion of structural units represented by general formula (10) in the total structural units of polymer P is preferably 1 to 15 mol%, more preferably 2 to 10 mol%.

In one embodiment, polymer P may contain structural units represented by formula (MA). These structural units undergo ring-opening with an alkaline developer to produce two carboxyl groups. Therefore, polymer P containing such structural units exhibits excellent developability. When polymer P contains structural units represented by general formula (MA), the proportion of these structural units in the total structural units of polymer P is preferably 1 to 35 mol%, more preferably 2 to 30 mol%.

In general formula (P), the divalent to hexavalent organic group Y is derived from a compound containing two or more thiol groups. Examples of compounds containing two or more thiol groups that can derive Y include those represented by the following chemical formulas (s-1) to (s-21).

A thiol group-containing compound with two or more functions may be used alone or in a mixture of two or more. In particular, it is preferable to use a thiol group-containing compound with three to six functions (three to six valents) having three to six thiol groups in one molecule, as it exhibits excellent reactivity with other monomers.
In this embodiment, the thiol group-containing compound with two or more functions more preferably includes compounds represented by chemical formulas (S-1) to (S-21), (S-3), (S-5), and (S-8) to (S-10), and is particularly more preferably includes compounds represented by chemical formulas (S-1) to (S-3), (S-5), and (S-9).
The organic group (i) Y, which has 1 to 6 valent carbon atoms and 1 to 30 carbon atoms, is bonded to the structural unit in [ ]n and/or the structural unit in [ ]m via a thioether group (-S-* (* is a bonding hand)) derived from the thiol group of these thiol group-containing compounds. The organic group (i) may have a thiol group that does not participate in bonding to the structural unit in [ ]n and the structural unit in [ ]m.

If Y in polymer P of this embodiment is an organic group derived from a tetrafunctional (tetravalent) thiol group-containing compound represented by the above-described chemical formula (s-2), polymer P may have a structure represented, for example, by the following general formula (I).

The structure of general formula (I) corresponds to the case in general formula (P) where m is 0 and n is 4. In general formula (I), A, B, C, X, p, q, and r are synonymous with those in general formula (P). The A, B, C, X, p, q, and r contained within the four structural units [ ] may be identical or different.

In general formula (I), the bonding order of A, B, and C is not particularly limited, and any of A, B, or C may be bonded to the thioether group. Furthermore, although general formula (I) is shown as an example where the four structural units within the brackets [ ] are bonded via thioether groups derived from the four mercapto groups of the compound represented by chemical formula (s-2), it is also possible to have a structure where 1 to 3 structural units within the brackets [ ] are bonded to the thioether groups derived from the four mercapto groups, and the remaining thioether groups are bonded to organic groups different from the structural units within the brackets [ ]. In this embodiment, polymer P can be obtained as a mixture containing at least one compound in which 1 to 4 of the structures within the brackets [ ] are bonded.

The weight-average molecular weight Mw of polymer P is, for example, 5,000 to 80,000, preferably 6,000 to 75,000, more preferably 7,000 to 70,000, and even more preferably 8,000 to 60,000. By appropriately adjusting the weight-average molecular weight, the sensitivity and solubility in alkaline developers can be adjusted.

Furthermore, the degree of dispersion of polymer P (weight-average molecular weight Mw/number-average molecular weight Mn) is preferably 1.0 to 5.0, more preferably 1.0 to 4.0, and even more preferably 1.0 to 3.0. Appropriately adjusting the degree of dispersion allows for homogenization of the properties of polymer P, which is preferable. These values can be determined by gel permeation chromatography (GPC) measurement using polystyrene as a standard substance.

The glass transition temperature of polymer P is preferably 150 to 250°C, more preferably 170 to 230°C. Polymer P has a relatively high glass transition temperature due to primarily containing structural units represented by the general formula (IN). This is advantageous in the manufacturing of liquid crystal displays and solid-state image sensors, as it allows for the stable existence of patterns formed on the substrate. The glass transition temperature can be determined, for example, by differential thermal analysis (DTA).

The acid value of polymer P is 70 mg KOH/g or more and 150 mg KOH/g or less, preferably 80 mg KOH/g or more and 140 mg KOH/g or less. The double bond equivalent of polymer P is 100 g/mol or more and 700 g/mol or less, preferably 200 g/mol or more and 600 g/mol or less, more preferably 200 g/mol or more and 430 g/mol or less.
By having an acid value of 70 mgKOH/g or higher for polymer P, good developability can be obtained. Furthermore, by having a double bond equivalent of 700 g/mol or less, the sensitivity of the photosensitive resin composition containing polymer P can be increased.

Furthermore, if the acid value of polymer P is too high, there is a concern that the exposed areas may dissolve easily during development with an alkaline developer, leading to an increased exposure amount required for photocuring or an insufficient pattern shape. Therefore, in this embodiment, the upper limit of the acid value is set to 150 mg KOH/g.
Furthermore, if the double bond equivalent of polymer P is too small (i.e., if the density of double bonds in the polymer is too high), unexposed or underexposed areas tend to be difficult to dissolve during development with an alkaline developer, and residual film tends to form during development. Also, if the double bond equivalent is too small, the molecular weight may increase excessively due to crosslinking, raising concerns about an excessive decrease in solubility. Therefore, in this embodiment, the lower limit of the double bond equivalent is set to 100 g/mol.

By adjusting the acid value and/or double bond equivalent of polymer P, it is possible to achieve an even higher level of balance between sensitivity and developability.

The acid value and double bond equivalent of polymer P can be determined by spectral measurement or other methods. For example, they can be determined by the following procedure (see the examples for more details).
(1) From the ^1H -NMR chart of the polymer, determine the area (integral value) of the peaks corresponding to the hydrogen atoms of the carboxyl group and the hydrogen atoms near the polymerizable carbon-carbon double bond.
(2) The area obtained in (1) is used to determine the amount of carboxyl groups and carbon-carbon double bonds from the area of the peaks originating from the standard substance.
(3) Convert the amount of carboxyl groups obtained in (2) into an acid value (mg KOH/g). Also, convert the amount of polymerizable carbon-carbon double bonds obtained in (2) into double bond equivalents (g/mol).

The acid value and double bond equivalent of polymer P can be adjusted to desired values by appropriately designing the ratio of structural units introduced into polymer P, particularly the number of polymerizable carbon-carbon double bonds in the (meth)acryloyl groups contained in the structural units represented by formulas (1) to (3).

The content (ratio) of each structural unit contained in polymer P of this embodiment can be estimated/calculated from the amount (moles) of raw materials charged during polymer synthesis, the amount of raw materials remaining after synthesis, and the peak areas of various spectra (for example, the peak area of ^1H -NMR).

(Second Embodiment)
In the second embodiment, polymer P may be a polymer obtained by polymerizing a monomer composition containing an indene monomer represented by the following formula (INm) and maleic anhydride in the presence of a bifunctional or thiol group-containing compound to prepare a raw material polymer, and then reacting this raw material polymer with a polyfunctional (meth)acrylic compound and/or a monofunctional (meth)acrylic compound in the presence of a basic catalyst. In formula (INm), ^R1 and ^R2 are the same as those in formula (IN).

The polymer P obtained by the above method includes a structural unit represented by formula (IN) derived from indene monomer, and a structural unit represented by formula (5) and/or formula (6) derived from maleic anhydride and a polyfunctional (meth)acrylic compound and/or a monofunctional (meth)acrylic compound.

(Third embodiment)
In a third embodiment, polymer P may be a polymer obtained by polymerizing a monomer composition containing the monomer represented by the above formula (INm) and maleic anhydride in the presence of a thiol group-containing compound with two or more functionalities to prepare a raw material polymer, then reacting this raw material polymer with a polyfunctional (meth)acrylic compound and/or a monofunctional methacrylic compound in the presence of a basic catalyst to prepare a polymer precursor, and then treating this polymer precursor with water in the presence of a basic catalyst.

The polymer P obtained by the above method includes a structural unit represented by formula (IN) derived from indene monomer, a structural unit represented by formula (5) and/or formula (6) derived from maleic anhydride and a polyfunctional (meth)acrylic compound and/or a monofunctional (meth)acrylic compound, and a structural unit represented by formula (10) derived from the reaction of maleic anhydride and water.

(Fourth embodiment)
In the fourth embodiment, polymer P may be a polymer obtained by polymerizing a monomer composition containing the monomer represented by the above formula (INm) and maleic anhydride in the presence of a thiol group-containing compound with two or more functionalities to prepare a raw material polymer, then reacting this raw material polymer with a polyfunctional (meth)acrylic compound and/or a monofunctional (meth)acrylic compound in the presence of a basic catalyst to prepare a polymer precursor, and then reacting this polymer precursor with an epoxy group-containing (meth)acrylic compound in the presence of a catalyst.

The polymer P obtained by the above method includes a structural unit represented by formula (IN) derived from indene monomer, a structural unit represented by formula (5) and/or formula (6) derived from maleic anhydride and a polyfunctional (meth)acrylic compound and/or a monofunctional (meth)acrylic compound, and a structural unit represented by formula (7) and/or formula (8) derived from maleic anhydride and a polyfunctional (meth)acrylic compound and/or a monofunctional (meth)acrylic compound and an epoxy group-containing (meth)acrylic compound.

[Method for producing polymer P]
The method for producing polymer P in this embodiment will be explained using the methods for producing polymer P in the second, third, and fourth embodiments described above as examples.

(Method for producing polymer P according to the second embodiment)
The polymer P of the second embodiment, which includes the structural unit represented by formula (5) and/or the structural unit represented by formula (6),
The polymer can be produced by the following steps: (I) preparing a raw material polymer containing a structural unit represented by general formula (IN), a structural unit represented by general formula (MA), and the aforementioned organic group (i) having 1 to 6 valent carbon atoms with 1 to 30 carbon atoms; and (II) reacting the raw material polymer obtained in step (I) with a compound having a hydroxyl group and two or more (meth)acryloyl groups (hereinafter referred to as a "polyfunctional (meth)acrylic compound") and/or a compound having a hydroxyl group and one (meth)acryloyl group (hereinafter referred to as a "monofunctional (meth)acrylic compound") in the presence of a basic catalyst to prepare a polymer P containing a structural unit represented by general formula (IN), the aforementioned organic group (i) having 1 to 6 valent carbon atoms with 1 to 30 carbon atoms, and a structural unit represented by general formula (5) and/or a structural unit represented by general formula (6), and optionally further containing a structural unit represented by general formula (MA).

In step (II), when both polyfunctional (meth)acrylic compounds and monofunctional (meth)acrylic compounds are used, it is preferable to first react the polyfunctional (meth)acrylic compound with the raw material polymer, and then react the resulting reaction mixture with the monofunctional (meth)acrylic compound.

(Method for producing polymer P according to the third embodiment)
The polymer P of the third embodiment, which includes the structural unit represented by formula (5) and/or the structural unit represented by formula (6), and the structural unit represented by formula (10),
Step (I): A step of preparing a raw material polymer containing a structural unit represented by general formula (IN), a structural unit represented by general formula (MA), and the aforementioned organic group (i) having 1 to 6 valent carbon atoms with 1 to 30 carbon atoms; and Step (II): A step of reacting the raw material polymer obtained in Step (I) with a compound having a hydroxyl group and two or more (meth)acryloyl groups (hereinafter referred to as a "polyfunctional (meth)acrylic compound") and/or a compound having a hydroxyl group and one (meth)acryloyl group (hereinafter referred to as a "monofunctional (meth)acrylic compound") in the presence of a basic catalyst to prepare a polymer precursor containing a structural unit represented by general formula (IN), the aforementioned organic group (i) having 1 to 6 valent carbon atoms with 1 to 30 carbon atoms, a structural unit represented by general formula (5) and/or a structural unit represented by general formula (6), and a structural unit represented by general formula (MA).
Step (IIIa): The polymer can be produced by treating the polymer precursor obtained in Step (II) with water in the presence of a base catalyst to prepare a polymer P comprising a structural unit represented by general formula (IN), the organic group (i) having 1 to 6 valent carbon atoms with 1 to 30 carbon atoms, a structural unit represented by general formula (5) and/or general formula (6), and a structural unit represented by formula (10), and optionally further comprising a structural unit represented by general formula (MA).

In step (II), when both polyfunctional (meth)acrylic compounds and monofunctional (meth)acrylic compounds are used, it is preferable to first react the polyfunctional (meth)acrylic compound with the raw material polymer, and then react the resulting reaction mixture with the monofunctional (meth)acrylic compound.

(Method for producing polymer P according to the fourth embodiment)
The polymer P of the fourth embodiment, which includes the structural unit represented by formula (5) and/or the structural unit represented by formula (6), and the structural unit represented by formula (8) and/or the structural unit represented by formula (9),
Step (I): A step of preparing a raw material polymer comprising a structural unit represented by general formula (IN), a structural unit represented by general formula (MA), and the aforementioned organic group (i) having 1 to 6 valent carbon atoms with 1 to 30 carbon atoms.
Step (II): The raw material polymer obtained in Step (I) is reacted with a compound having a hydroxyl group and two or more (meth)acryloyl groups (hereinafter referred to as a "polyfunctional (meth)acrylic compound") and/or a compound having a hydroxyl group and one (meth)acryloyl group (hereinafter referred to as a "monofunctional (meth)acrylic compound") in the presence of a basic catalyst to obtain a structural unit represented by general formula (IN), the aforementioned organic group (i) having 1 to 6 valent carbon atoms and 1 to 30 carbon atoms, a structural unit represented by general formula (5) and/or a structural unit represented by general formula (6), and optionally general formula (M The polymer can be produced by the steps of: preparing a polymer precursor containing the structural unit represented by A); and step (IIIb): reacting the polymer precursor obtained in step (II) with an epoxy group-containing (meth)acrylic compound in the presence of a catalyst to prepare a polymer P containing the structural unit represented by general formula (IN), the 1- to 6-valent organic group (i) having 1 to 30 carbon atoms, the structural unit represented by general formula (5) and/or the structural unit represented by general formula (6), the structural unit represented by general formula (7) and/or the structural unit represented by general formula (8), and optionally the structural unit represented by general formula (MA).

In step (II), when both polyfunctional (meth)acrylic compounds and monofunctional (meth)acrylic compounds are used, it is preferable to first react the polyfunctional (meth)acrylic compound with the raw material polymer, and then react the resulting reaction mixture with the monofunctional (meth)acrylic compound.

The following describes each step.
(Step (I))
The step of preparing a raw material polymer in step (I) that includes a structural unit represented by general formula (IN), a structural unit represented by general formula (MA), and the organic group (i) having 1 to 6 valent carbon atoms and 1 to 30 carbon atoms can be carried out by polymerizing (addition polymerization) a monomer composition containing an indene monomer represented by general formula (INm) and maleic anhydride in the presence of the thiol group-containing compound with two or more functionalities. The definitions of ^R1 and ^R2 in general formula (INm) are the same as those for general formula (IN). The same applies to preferred embodiments.

The monomer composition may contain other monomers in addition to the above monomer. The other monomers are not particularly limited as long as they are copolymerizable compounds having a double bond. Examples include substituted or unsubstituted norbornene, maleimide, styrene, acenaphthylene, norbornadiene, dihydrofuran, terpene compounds (e.g., pinene, limonene, etc.), linear alkenes (e.g., pentene, etc.), cyclic alkenes (e.g., cyclohexene, etc.), cyclododecatriene, tricycloundecane, dialkyl fumarates (e.g., dimethyl fumarate, ethyl fumarate, dibutyl fumarate, etc.), coumarin, (meth)acrylic acid compounds (e.g., methyl methacrylate, methyl acrylate), vinyl acetate, vinyl ethers (e.g., 2-hydroxyethyl vinyl ether, etc.). In step (I), the monomer represented by general formula (INm), maleic anhydride, and other monomers as needed can be polymerized (addition polymerized) in the presence of the thiol group-containing compound with two or more functionalities.

Examples of thiol group-containing compounds with two or more functions include, but are not limited to, the compounds represented by the chemical formulas (S-1) to (S-21) above. A single thiol group-containing compound with two or more functions may be used, or two or more may be used in combination.

While the polymerization method is not limited, radical polymerization using a radical polymerization initiator is preferred. Examples of polymerization initiators include azo compounds and organic peroxides.
Specific examples of azo compounds include azobisisobutyronitrile (AIBN), dimethyl 2,2'-azobis(2-methylpropionate), and 1,1'-azobis(cyclohexanecarbonitride) (ABCN).
Examples of organic peroxides include hydrogen peroxide, di-tert-butyl peroxide (DTBP), benzoyl peroxide (benzoyl peroxide, BPO), and methyl ethyl ketone peroxide (MEKP).
Regarding polymerization initiators, one type may be used alone, or two or more types may be used in combination.

For the polymerization reaction, organic solvents such as diethyl ether, tetrahydrofuran, toluene, and methyl ethyl ketone can be used as solvents. The polymerization solvent may be a single solvent or a mixture of solvents.

The synthesis of the raw material polymer is carried out by dissolving a monomer represented by formula (INm), maleic anhydride, and a polymerization initiator in a solvent and charging them into a reaction vessel, then heating and adding the thiol group-containing compound with two or more functionalities dropwise to allow addition polymerization to proceed. The heating temperature is, for example, 50 to 80°C, and the heating time is, for example, 5 to 20 hours.
When charging the reaction vessel, the molar ratio of the monomer represented by formula (INm) to maleic anhydride is preferably 0.5:1 to 1:0.5. From the viewpoint of controlling the molecular structure, a molar ratio of 1:1 is preferable.
Furthermore, from the viewpoint of controlling the thioether group content in the raw material polymer and the molecular weight of the raw material polymer, the amount of the thiol group-containing compound with two or more functions added to the reaction vessel is preferably 0.5 to 10 mol%, particularly preferably 1 to 8 mol%, and even more preferably 2 to 6 mol%, relative to the total molar amount of the monomer represented by formula (INm) and maleic anhydride added.
Through this process, "raw material polymers" can be obtained.
The raw material polymer may be any of the following: random copolymer, alternating copolymer, block copolymer, or periodic copolymer. Typically, it is a random copolymer or alternating copolymer. Maleic anhydride is generally known as a monomer with strong alternating copolymerizability.

Furthermore, after the synthesis of the raw material polymer, a step may be taken to remove low molecular weight components such as unreacted monomers, oligomers, and residual polymerization initiators.
Specifically, the organic phase containing the synthesized raw material polymer and low molecular weight components is concentrated, and then mixed with an organic solvent such as tetrahydrofuran (THF) to obtain a solution. This solution is then mixed with a poor solvent such as methanol to precipitate the monomers. By filtering and drying this precipitate, the purity of the raw material polymer can be increased.

(Step (II))
By reacting the raw material polymer obtained in step (I) with a polyfunctional (meth)acrylic compound and/or a monofunctional (meth)acrylic compound in the presence of a basic catalyst, some of the structural units represented by formula (MA) contained in the raw material polymer undergo ring opening, forming structural units represented by formula (5) and/or formula (6), thereby obtaining a polymer P containing a structural unit represented by general formula (IN), the aforementioned organic group (i) having 1 to 6 valent carbon atoms with 1 to 30 carbon atoms, and structural units represented by general formula (5) and/or general formula (6), and optionally containing a structural unit represented by formula (MA).

More specifically, first, a solution is prepared by dissolving the raw material polymer in a suitable organic solvent. As the organic solvent, single or mixed solvents such as methyl ethyl ketone (MEK), propylene glycol monomethyl ether acetate (PGMEA), dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), and tetrahydrofuran (THF) can be used, but are not limited to these; various organic solvents used in the synthesis of organic compounds and polymers can be used.

To obtain polymer P containing both the structural unit represented by general formula (IN) and the structural unit represented by general formula (5), a polyfunctional (meth)acrylic compound is added to the above solution. Furthermore, a basic catalyst is added. The solution is then appropriately mixed to obtain a homogeneous solution, thereby obtaining a polymer containing a structure in which at least the structural unit of general formula (IN) and the structural unit of general formula (5) are bonded to the organic group (i) having 1 to 30 carbon atoms via 1 to 6 thioether groups (step (II-i)).

Examples of polyfunctional (meth)acrylic compounds that can be used here include the compound represented by formula (1b-m), the compound represented by formula (1c-m), and the compound represented by formula (1d-m). The definitions and specific embodiments of k, R, X1, X1', and X2 in formula (1b-m) are the same as those in formula (1b) described above. The definitions and specific embodiments of k, R, ^X1 , ^X2 , ^X3 , ^X4 , ^X5 , and ^X6 in formula (1c-m) are the same as those in formula (1c) described above. The values of n and R in formula (1d-m) are the same as those in formula (1d) described above.

Next, the polymer obtained in step (II-i) is reacted with a monofunctional (meth)acrylic compound in the presence of a basic catalyst to obtain a polymer containing a structure in which at least the structural unit of general formula (IN), the structural unit of general formula (5), and the structural unit of general formula (6) are bonded to the organic group (i) having 1 to 30 carbon atoms via 1 to 6 thioether groups (step (II-ii)).

As a basic catalyst, amine compounds and nitrogen-containing heterocyclic compounds known in the field of organic synthesis can be used as appropriate. For example, amine compounds such as triethylamine, pyridine, and dimethylaminopyridine, or nitrogen-containing heterocyclic compounds, can be used as catalysts. The amount of basic catalyst used can be, for example, about 10 to 60 parts by mass per 100 parts by mass of the raw material polymer. Note that using an excess of basic catalyst may increase the amount of acid required for neutralization, potentially complicating the purification process.

By heating the above solution at a temperature of preferably 60 to 80°C for approximately 3 to 9 hours, ring-opening of the structural unit of general formula (MA) and formation of the structural unit of general formula (5) are achieved in the raw material polymer.

Furthermore, for example, by adding a monofunctional (meth)acrylic compound containing a hydroxyl group to the reaction system during the heating process described above, the structural unit represented by the aforementioned general formula (6) can be introduced into polymer P.

Due to steric hindrance and other factors, monofunctional (meth)acrylic compounds containing hydroxyl groups tend to react more readily with the starting polymer than polyfunctional (meth)acrylic compounds containing hydroxyl groups. Therefore, when introducing the structural unit represented by the general formula (6) into polymer P, it is preferable not to add the monofunctional (meth)acrylic compound containing hydroxyl groups to the reaction system from the beginning, but rather to add it to the reaction system later.
Examples of monofunctional (meth)acrylic compounds having a hydroxyl group include compounds represented by the following general formula (2a-m).
In general formula (2a-m), the definitions of X ¹⁰ and R are the same as those in general formula (2a).

Specific examples of compounds represented by the general formula (2a-m) include 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 1,4-cyclohexanedimethanol mono(meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, and 2-(meth)acryloyloxyethyl-2-hydroxyethyl-phthalic acid.

When obtaining a polymer containing a structural unit represented by formula (IN), an organic group (i) having 1 to 6 valent carbon atoms with 1 to 30 carbon atoms, and either the structural unit represented by formula (1) or the structural unit represented by formula (2), only one of steps (II-i) or (II-ii) needs to be carried out after step (I).
(Step (IIIa))
When carrying out step (IIIa), a step is used in which the polymer obtained in step (II) is treated with water in the presence of a basic catalyst. Step (IIIa) causes the structural unit represented by general formula (MA) contained in the polymer obtained in step (II) to open its ring, forming the structural unit represented by general formula (10), thereby producing a polymer P containing the structural unit represented by general formula (IN), the structural unit represented by general formula (5) and/or the structural unit represented by general formula (6), and the structural unit represented by general formula (10). If some of the structural unit represented by general formula (MA) opens its ring and some of the structural unit of general formula (MA) remains without opening its ring, the polymer P contains the structural unit represented by general formula (IN), the structural unit of general formula (5) and/or the structural unit of general formula (6), the 1-6 valent organic group (i) having 1 to 30 carbon atoms, and the structural unit of general formula (310), in addition to the structural unit represented by general formula (MA).

Examples of basic catalysts used in step (IIIa) include amine compounds such as triethylamine, pyridine, and dimethylaminopyridine, or nitrogen-containing heterocyclic compounds.

In step (IIIa), water is added to the reaction system containing the polymer precursor obtained in step (II), and the resulting reaction solution is heated, preferably at 60-80°C for about 0.25-6 hours. This causes the structural unit of formula (MA) in the polymer to open its ring, generating the structural unit represented by formula (10). The basic catalyst can be the same catalyst remaining in the reaction system obtained in step (II). Therefore, it is preferable to carry out step (IIIa) by adding water to the reaction mixture obtained in step (II) in situ, without any post-treatment of the mixture.

The polymer P of this embodiment can be obtained through the above steps. However, from the viewpoint of the effects of the present invention, the following steps may be performed as appropriate to remove unwanted components other than the desired polymer.

First, the reaction solution, diluted with an organic solvent and to which an acid (e.g., formic acid) has been added, is vigorously stirred in a separatory funnel for at least 3 minutes. This mixture is then allowed to stand for at least 30 minutes to separate the organic phase from the aqueous phase, and the aqueous phase is removed. In this way, an organic solution of the polymer is obtained.

The obtained organic solution containing polymer P is purified using either a reprecipitation method or a liquid-liquid extraction method. In the reprecipitation method, the obtained organic solution of polymer P is added to an excess amount of toluene or water to reprecipitation the polymer. The polymer powder obtained by reprecipitation is then washed several more times with toluene or water.
Furthermore, in order to remove formic acid and basic catalysts, the obtained polymer powder is washed with deionized water several times (approximately 1 to 3 times).
High-purity polymers can be obtained by drying the polymer powder, after washing it with deionized water, at a temperature of, for example, 30-60°C for 16 hours or more.
In the liquid-liquid extraction method, water is added to the obtained organic solution of polymer P, and the mixture is vigorously stirred in a separatory funnel for at least 3 minutes. This mixture is then allowed to stand for at least 30 minutes to separate the organic phase from the aqueous phase, and the aqueous phase is removed. Water is then added to the organic solution of the polymer after the removal of the aqueous phase, and the mixture is vigorously stirred in a separatory funnel for at least 3 minutes. This mixture is then allowed to stand for at least 30 minutes to separate the organic phase from the aqueous phase, and the aqueous phase is removed. In this way, an organic solution of the polymer is obtained. If necessary, the steps of adding water and removing the aqueous phase may be repeated.
The obtained polymer organic solution can be concentrated by heating it under reduced pressure using a rotary evaporator, and then diluted by repeatedly adding a final solvent (such as PGMEA) to obtain a polymer P solution dissolved in the final solvent.

Furthermore, the polymer solution may contain the polyfunctional (meth)acrylic compound and/or monofunctional (meth)acrylic compound used in the synthesis of polymer P. When the polymer solution contains these (meth)acrylic compounds, it is preferable that the peak area derived from the polyfunctional (meth)acrylic compound in the gel permeation chromatography (GPC) chart is 5-50%, particularly 10-35%, of the peak area of polymer P, and the peak area derived from the monofunctional (meth)acrylic compound is 5-50%, particularly 10-35%, of the peak area of polymer P. As a result, the photosensitive resin composition containing this polymer solution has good alkali solubility and good sensitivity in photolithography.

(Step (IIIb))
In step (IIIa), the polymer precursor obtained in step (II) is reacted with an epoxy group-containing (meth)acrylic compound in the presence of a catalyst. The reaction between the carboxyl group of the polymer precursor and the epoxy group of the epoxy group-containing (meth)acrylic compound forms a structural unit represented by general formula (8) and/or general formula (9). This generates a polymer P containing a structural unit represented by general formula (IN), the 1- to 6-valent organic group (i) having 1 to 30 carbon atoms, a structural unit represented by general formula (5) and/or general formula (6), and a structural unit represented by general formula (8) and/or general formula (9), and optionally a structural unit represented by general formula (MA).

Step (IIIb) is preferably carried out by adding an epoxy group-containing (meth)acrylic compound to the reaction system containing the polymer precursor obtained in step (II).

The reaction between the polymer precursor and the epoxy group-containing (meth)acrylic compound proceeds in the presence of a basic catalyst. The basic catalyst can be the one remaining in the reaction system obtained in step (II). Therefore, it is preferable to carry out step (IIIb) by adding the epoxy group-containing (meth)acrylic compound to the reaction mixture containing the polymer precursor obtained in step (II) in situ, without isolating and purifying the polymer precursor from the reaction mixture containing the polymer precursor obtained in step (II) or neutralizing the basic catalyst contained in the mixture.

Specifically, the reaction solution obtained by adding an epoxy group-containing (meth)acrylic compound to a reaction mixture containing a polymer precursor is heated, preferably at 60-80°C, for about 1-9 hours. This reaction between the carboxyl groups of the polymer precursor (the carboxyl groups in formula (5) and/or formula (6)) and the epoxy groups of the epoxy group-containing (meth)acrylic compound forms structural units represented by general formula (8) and/or general formula (9), thereby generating polymer P.

Examples of epoxy group-containing (meth)acrylic compounds include glycidyl methacrylate (GMA), 4-hydroxybutyl acrylate glycidyl ether (4HBAGE), 3,4-epoxycyclohexyl methyl acrylate, 3,4-epoxycyclohexyl methyl methacrylate, and glycidyl acrylate. One or more of these can be used.

The amount of epoxy group-containing (meth)acrylic compound added is preferably 0.1 to 3.0 moles per mole of carboxyl groups in the polymer precursor.

After step (IIIb), it is preferable to perform the following steps as appropriate to remove unwanted components other than the desired polymer P.

First, the reaction solution, diluted with an organic solvent and to which an acid (e.g., formic acid, citric acid, etc.) has been added, is vigorously stirred in a separatory funnel for at least 3 minutes. This mixture is then allowed to stand for at least 30 minutes to separate the organic phase from the aqueous phase, and the aqueous phase is removed. In this way, an organic solution of polymer P is obtained.

An excess amount of toluene is added to the organic solution of polymer P obtained to reprecipitate polymer P. The polymer powder obtained by reprecipitation is then washed with toluene several more times (for example, twice).
Furthermore, to remove acidic and basic catalysts, the obtained polymer powder is washed with deionized water several times (for example, three times).
High-purity polymer (A) of this embodiment can be obtained by drying the polymer powder, after washing with deionized water, at a temperature of 30 to 60°C for 16 hours or more.

[Polymer solution]
The polymer solution of this embodiment contains the polymer P described above.
The polymer solution of this embodiment may contain, along with polymer (A), at least one selected from polyfunctional (meth)acrylic compounds, monofunctional (meth)acrylic compounds, and compounds having a thiol group and an alkoxy group or their oligomers.

(Polyfunctional (meth)acrylic compounds)
The polyfunctional (meth)acrylic compound or monofunctional (meth)acrylic compound that may be contained in the polymer solution of this embodiment may be unreacted (meth)acrylic compounds used in the production of polymer P, or may be added separately.

Examples of polyfunctional (meth)acrylic compounds that can be incorporated into polymer solutions include, but are not limited to, the compounds represented by the following general formulas: (1b-p), (1c-p), and (1d-p).

The definitions and specific embodiments of k, R, ^X1 , ^X1 ', and ^X2 in general formula (1b-p) are the same as those in general formula (1b) described above. Similarly, the definitions and specific embodiments of k, R, ^X1 , ^X2 , ^X3 , ^X4 , ^X5 , and ^X6 in general formula (1c-p) are the same as those in general formula (1c) described above.

In general formulas (1b-p), (1c-p), and (1d-p), Y is a hydrogen atom, a (meth)acryloyl group, or a combination thereof.

Compounds in which Y is a hydrogen atom in general formulas (1b-p), (1c-p), and (1d-p) may be unreacted monomers (i.e., compounds represented by general formulas (1b-p), (1c-p), and (1d-p)) and may be added separately.
In the general formula (1d-p), n is an integer of 2 or more, preferably an integer between 2 and 5, and more preferably an integer between 2 and 3.

When a polyfunctional (meth)acrylic compound is added to the polymer solution of this embodiment, separately from the unreacted polyfunctional (meth)acrylic compound used in the production of polymer P, the amount added can be such that the peak area derived from the polyfunctional (meth)acrylic compound in the gel permeation chromatography (GPC) chart of the polymer solution is preferably 10% or less, more preferably 5% or less, and even more preferably 2% or less, relative to the peak area of polymer P.

(Monofunctional (meth)acrylic compounds)
Examples of monofunctional (meth)acrylic compounds incorporated into the polymer solution of this embodiment include compounds represented by the following formula (2a-m). In formula (2a-m), the definitions of X ¹⁰ and R are the same as those in formula (2a).

When a monofunctional (meth)acrylic compound is added to the polymer solution of this embodiment, separately from the unreacted monofunctional (meth)acrylic compound used in the production of polymer P, the amount added can be such that the peak area derived from the monofunctional (meth)acrylic compound in the gel permeation chromatography (GPC) chart of the polymer solution is preferably 10% or less, more preferably 5% or less, and even more preferably 2% or less, relative to the peak area of polymer P.

(A compound having a thiol group and an alkoxy group, or its oligomer (Compound (B)))
The compound having a thiol group and an alkoxy group, or its oligomer (hereinafter referred to as "Compound (B)") that can be incorporated into the polymer solution of this embodiment, can be any known compound that has a thiol group and an alkoxy group, as long as it exhibits the effects of the present invention.

The polymer solution of this embodiment, by containing compound (B) or its oligomer, can provide a resin cured product with excellent adhesion to substrates and the like. The substrate is not particularly limited, but as described later, examples include glass substrates, silicon wafers, ceramic substrates, aluminum substrates, SiC wafers, GaN wafers, and copper-clad laminates.

In this embodiment, the alkoxy group contained in compound (B) is preferably a carbon-1 to carbon-3 alkoxy group from the viewpoint of the effects of the present invention, and it is also preferable that the compound has a structure in which a thiol group and an alkoxy group are bonded to an organic chain which may contain one or more atoms selected from O, N, S, P and Si.
Specifically, compound (B) preferably contains a compound represented by the following general formula (a).

In general formula (a), each R independently represents an alkoxy group having 1 to 3 carbon atoms or an alkyl group having 1 to 3 carbon atoms, and at least two of the Rs are alkoxy groups having 1 to 3 carbon atoms.
L represents an m+n valent organic chain which may contain one or more atoms selected from O, N, S, P, and Si.

In this embodiment, examples of the m+n valent organic chain of L include linear or branched alkylene groups (m+n:2) having 1 to 10 carbon atoms, m+n valent groups derived from linear or branched alkanes having 1 to 20 carbon atoms, and m+n valent groups derived from substituted or unsubstituted siloxanes.

X represents a single bond or a divalent organic group which may contain a carbonyl group, a (thio)ester group, or a (thio)amide group.
In this embodiment, X is preferably a single bond or an alkylene ester group having 1 to 10 carbon atoms.
Q represents a single bond or a divalent organic group which may contain a carbonyl group, a (thio)ester group, or a (thio)amide group.
In this embodiment, Q is preferably a single bond or an alkylene ester group having 1 to 10 carbon atoms.
The molar ratio (m:n) is between 1:1 and 1:8, and m+n is between 2 and 20.
The weight-average molecular weight of the compound is between 100 and 2000.

Examples of compound (B) include 3-mercaptopropylmethyldimethoxysilane (KBM-802, manufactured by Shin-Etsu Silicone Co., Ltd.), 3-mercaptopropyltrimethoxysilane (KBM-803, manufactured by Shin-Etsu Silicone Co., Ltd.), (3-mercaptopropyl)triethoxysilane, siloxane chain-containing polyfunctional silane coupling agent (KR-519, manufactured by Shin-Etsu Silicone Co., Ltd.), and organic chain-containing polyfunctional silane coupling agents having the following structural units.

In the above general formula, the molar ratio a:b is 2:1 to 4:1. The weight-average molecular weight is 1000 to 1500. * indicates a bond. Examples of such compounds include X-12-1154 (manufactured by Shin-Etsu Silicone Co., Ltd.).
Compound (B) or its oligomer may be used alone or as a mixture of two or more.

In the polymer solution of this embodiment, compound (B) is blended in an amount of 0.25 to 20% by mass, preferably 1.0 to 15% by mass, and more preferably 2.0 to 12% by mass, relative to the polymer P, from the viewpoint of the effects of the present invention.

The polymer solution of this embodiment typically contains an organic solvent and is provided in the form of a liquid or varnish. As the organic solvent, one or more of the following can be used: ketone solvents, ester solvents, ether solvents, alcohol solvents, lactone solvents, carbonate solvents, etc.

Specific examples of organic solvents include propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, γ-butyl lactone, N-methylpyrrolidone, and cyclohexanone. These may be used individually or in combination of two or more.
The amount of organic solvent used is not particularly limited, but it is used in such an amount that the concentration of nonvolatile components is, for example, 10 to 70% by mass, preferably 15 to 60% by mass.

[Production of polymer solutions]
The polymer solution of this embodiment can be prepared by mixing the above components by a known method. The polymer solution of this embodiment is used as a resin material in the photosensitive resin composition described below.

[Photosensitive resin composition]
The photosensitive resin composition of this embodiment comprises the polymer P described above and a photopolymerization initiator. That is, the photosensitive resin composition of this embodiment comprises the polymer solution of this embodiment described above and a photopolymerization initiator. Each component is described below.

(Photopolymerization initiator)
Examples of photopolymerization initiators used in the photosensitive resin composition of this embodiment include photoradical polymerization initiators. Known compounds can be used as photoradical polymerization initiators, for example, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl}-2-methylpropan-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, 2-(dimethylamino)-2-[(4-methylphenyl) Alkylphenone compounds such as methyl-1-[4-(4-morpholinyl)phenyl]-1-butanone; benzophenone compounds such as benzophenone, 4,4'-bis(dimethylamino)benzophenone, and 2-carboxybenzophenone; benzoin compounds such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; thioxanthone compounds such as thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, and 2,4-diethylthioxanthone; 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, and 2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-s-triazine Halomethylated triazine compounds such as 2-(4-ethoxynaphthyl)-4,6-bis(trichloromethyl)-s-triazine and 2-(4-ethoxycarboquinylnaphthyl)-4,6-bis(trichloromethyl)-s-triazine; halomethylated oxadiazole compounds such as 2-trichloromethyl-5-(2'-benzofuryl)-1,3,4-oxadiazole, 2-trichloromethyl-5-[β-(2'-benzofuryl)vinyl]-1,3,4-oxadiazole, 4-oxadiazole, and 2-trichloromethyl-5-furyl-1,3,4-oxadiazole; 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole and 2,2'-bis(2,4-dichlorophenyl)-4,4',5,5'-tetraphenyl-1,2 Examples include biimidazole compounds such as '-biimidazole and 2,2'-bis(2,4,6-trichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole; oxime ester compounds such as 1,2-octanedione, 1-[4-(phenylthio)-2-(O-benzoyl oxime)], etanone, and 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(O-acetyl oxime); titanocene compounds such as bis(η5-2,4-cyclopentadiene-1-yl)-bis(2,6-difluoro-3-(1H-pyrrole-1-yl)-phenyl)titanium; benzoic acid ester compounds such as p-dimethylaminobenzoic acid and p-diethylaminobenzoic acid; and acridine compounds such as 9-phenylacridine. The photoradical polymerization initiator may be used alone or in combination of two or more types.
The photoradical polymerization initiator is used in an amount of, for example, 1 to 20 parts by mass, preferably 3 to 10 parts by mass, per 100 parts by mass of polymer.

The photosensitive resin composition of this embodiment, by containing the above-mentioned components, exhibits high sensitivity in photolithography and excellent alkali solubility. Therefore, the photosensitive resin composition possesses excellent developability and processability in photolithography.

(Coloring agent)
In one embodiment, the photosensitive resin composition may contain a coloring agent. The inclusion of a coloring agent makes it suitable for use as a material for forming color filters in liquid crystal displays and solid-state image sensors. Various pigments or dyes can be used as the coloring agent.
Organic pigments and inorganic pigments can be used as pigments.

As organic pigments, azo pigments, phthalocyanine pigments, quinacridone pigments, perylene pigments, perinone pigments, isoindolinone pigments, isoindoline pigments, dioxazine pigments, thioindigo pigments, anthraquinone pigments, quinophthalone pigments, metal complex pigments, diketopyrrolopyrrole pigments, xanthene pigments, pyromethene pigments, dye lake pigments, etc. can be used.

Inorganic pigments that can be used include white and extender pigments (titanium dioxide, zinc oxide, zinc sulfide, clay, talc, barium sulfate, calcium carbonate, etc.), chromatic pigments (lead yellow, cadmium-based pigments, chrome vermilion, nickel titanium, chromium titanium, yellow iron oxide, red iron oxide, zinc chromate, red lead, ultramarine, Prussian blue, cobalt blue, chrome green, chromium oxide, bismuth vanadate, etc.), luminescent pigments (pearl pigments, aluminum pigments, bronze pigments, etc.), and fluorescent pigments (zinc sulfide, strontium sulfide, strontium aluminate, etc.).

As dyes, for example, known dyes described in Japanese Patent Publication No. 2003-270428, Japanese Patent Publication No. 9-171108, Japanese Patent Publication No. 2008-50599, etc., can be used.
If the photosensitive resin composition contains a coloring agent, the photosensitive resin composition may contain only one type of coloring agent or two or more types.

Colorants (especially pigments) can be selected based on their purpose and application, while those with an appropriate average particle size are preferred. For applications requiring transparency, such as color filters, a small average particle size of 0.1 μm or less is preferable. For other applications requiring opacity, such as paints, a larger average particle size of 0.5 μm or more is preferred.

Depending on the purpose and application, the colorants may undergo surface treatments such as rosin treatment, surfactant treatment, resin-based dispersant treatment, pigment derivative treatment, oxide film treatment, silica coating, or wax coating.

When a photosensitive resin composition contains a colorant, the amount can be appropriately set according to the purpose and application. However, considering the balance between color concentration and dispersion stability of the colorant, the amount is preferably 3 to 70% by mass, more preferably 5 to 60% by mass, and even more preferably 10 to 50% by mass, relative to the total nonvolatile components (components excluding solvents) of the photosensitive resin composition.

(Surfactants)
The photosensitive resin composition of this embodiment may contain a surfactant, and a nonionic surfactant is preferred as the surfactant.

The inclusion of a nonionic surfactant improves the coatability of the photosensitive resin composition when applying it to a substrate to obtain a resin film, resulting in a uniformly thick coating. Furthermore, it prevents residue and pattern lifting during the development of the coating.

Nonionic surfactants are, for example, compounds containing a fluorine group (e.g., a fluorinated alkyl group) or a silanol group, or compounds with a siloxane bond as the main skeleton. In this embodiment, it is more preferable to use a nonionic surfactant that includes a fluorine-based surfactant or a silicone-based surfactant, and it is particularly preferable to use a fluorine-based surfactant. Examples of fluorine-based surfactants include, but are not limited to, Megafac F-171, F-173, F-444, F-470, F-471, F-475, F-482, F-477, F-554, F-556, and F-557 from DIC Corporation, and Novec FC4430 and FC4432 from Sumitomo 3M Co., Ltd.
When using a surfactant, the amount of surfactant added is preferably 0.01 to 10% by weight per 100 parts by mass of resin.

(solvent)
Photosensitive resin compositions typically contain a solvent. Organic solvents are preferred as the solvent. Specifically, one or more of the following can be used: ketone solvents, ester solvents, ether solvents, alcohol solvents, lactone solvents, carbonate solvents, etc.

Examples of solvents include propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), ethyl lactate, methyl isobutylcarbinol (MIBC), gamma butyrolactone (GBL), N-methylpyrrolidone (NMP), methyl-n-amyl ketone (MAK), diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, cyclohexanone, or mixtures thereof.
The amount of solvent used is not particularly limited, but it is used in such an amount that the concentration of nonvolatile components is, for example, 10 to 70% by mass, preferably 15 to 60% by mass.

(Light-blocking agent)
The resin composition of this embodiment may contain a light-shielding agent. The photosensitive resin composition may contain only one type of light-shielding agent, or it may contain two or more types.

When a photosensitive resin composition contains a light-shielding agent, the amount can be appropriately set according to the purpose and application. However, in order to balance light-shielding performance and dispersion stability of the light-shielding agent, the amount is preferably 3 to 70% by mass, more preferably 5 to 60% by mass, and even more preferably 10 to 50% by mass, relative to the total non-volatile components (components excluding solvents) of the photosensitive resin composition.

(Crosslinking agent)
The photosensitive resin composition of this embodiment may contain a crosslinking agent.
The crosslinking agent is not particularly limited as long as it is capable of crosslinking the polymer (being able to chemically bond with the polymer) through the action of activated chemical species generated from the photopolymerization initiator.
The crosslinking agent may not only chemically bond with the polymer, but may also react with other crosslinking agents to form bonds.

The crosslinking agent is preferably a polyfunctional compound having two or more polymerizable double bonds in one molecule, and more preferably a polyfunctional (meth)acrylic compound having two or more (meth)acryloyl groups in one molecule (however, the crosslinking agent does not fall under the polymers mentioned above). Using a crosslinking agent having the same type of crosslinkable group (polymerizable double bond) as the polymer is preferable in terms of uniform curability and further improvement of sensitivity.
There is no particular upper limit to the number of functionalities (number of polymerizable double bonds) per molecule of the crosslinking agent, but it is, for example, 8 or less, preferably 6 or less.

Specifically, the crosslinking agents include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, hexanediol di(meth)acrylate, cyclohexanedimethanol di(meth)acrylate, bisphenol A alkylene oxide di(meth)acrylate, bisphenol F alkylene oxide di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, glycerin tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ethylene oxide-added trimethylolpropane tri(meth)acrylate, ethylene Polyfunctional (meth)acrylates such as oxide-added ditrimethylolpropanetetra(meth)acrylate, ethylene oxide-added pentaerythritoltetra(meth)acrylate, ethylene oxide-added dipentaerythritol hexa(meth)acrylate, propylene oxide-added trimethylolpropanetri(meth)acrylate, propylene oxide-added ditrimethylolpropanetetra(meth)acrylate, propylene oxide-added pentaerythritoltetra(meth)acrylate, propylene oxide-added dipentaerythritol hexa(meth)acrylate, ε-caprolactone-added trimethylolpropanetri(meth)acrylate, ε-caprolactone-added ditrimethylolpropanetetra(meth)acrylate, ε-caprolactone-added pentaerythritoltetra(meth)acrylate, ε-caprolactone-added dipentaerythritol hexa(meth)acrylate, etc.
Polyfunctional vinyl ethers such as ethylene glycol divinyl ether, diethylene glycol divinyl ether, polyethylene glycol divinyl ether, propylene glycol divinyl ether, butylene glycol divinyl ether, hexanediol divinyl ether, bisphenol A alkylene oxide divinyl ether, bisphenol F alkylene oxide divinyl ether, trimethylolpropane trivinyl ether, ditrimethylolpropane tetravinyl ether, glycerin trivinyl ether, pentaerythritol tetravinyl ether, dipentaerythritol pentavinyl ether, dipentaerythritol hexanyl ether, ethylene oxide-added trimethylolpropane trivinyl ether, ethylene oxide-added ditrimethylolpropane tetravinyl ether, ethylene oxide-added pentaerythritol tetravinyl ether, and ethylene oxide-added dipentaerythritol hexanyl ether;
Vinyl ether group-containing (meth)acrylic acid esters such as 2-vinyloxyethyl (meth)acrylate, 3-vinyloxypropyl (meth)acrylate, 1-methyl-2-vinyloxyethyl (meth)acrylate, 2-vinyloxypropyl (meth)acrylate, 4-vinyloxybutyl (meth)acrylate, 4-vinyloxycyclohexyl (meth)acrylate, 5-vinyloxypentyl (meth)acrylate, 6-vinyloxyhexyl (meth)acrylate, 4-vinyloxymethylcyclohexylmethyl (meth)acrylate, p-vinyloxymethylphenylmethyl (meth)acrylate, 2-(vinyloxyethoxy)ethyl (meth)acrylate, and 2-(vinyloxyethoxyethoxyethoxyethoxy)ethyl (meth)acrylate;
Polyfunctional allyl ethers such as ethylene glycol diallyl ether, diethylene glycol diallyl ether, polyethylene glycol diallyl ether, propylene glycol diallyl ether, butylene glycol diallyl ether, hexanediol diallyl ether, bisphenol A alkylene oxide diallyl ether, bisphenol F alkylene oxide diallyl ether, trimethylolpropane triallyl ether, ditrimethylolpropane tetraallyl ether, glycerin triallyl ether, pentaerythritol tetraallyl ether, dipentaerythritol pentaallyl ether, dipentaerythritol hexaallyl ether, ethylene oxide-added trimethylolpropane triallyl ether, ethylene oxide-added ditrimethylolpropane tetraallyl ether, ethylene oxide-added pentaerythritol tetraallyl ether, and ethylene oxide-added dipentaerythritol hexaallyl ether;
Allyl group-containing (meth)acrylic acid esters, such as allyl (meth)acrylic acid;
Polyfunctional (meth)acryloyl group-containing isocyanurates such as tri(acryloyloxyethyl) isocyanurate, tri(methacryloyloxyethyl) isocyanurate, alkylene oxide-added tri(acryloyloxyethyl) isocyanurate, and alkylene oxide-added tri(methacryloyloxyethyl) isocyanurate;
Polyfunctional allyl group-containing isocyanurates, such as triallyl isocyanurate;
Polyfunctional urethane (meth)acrylates obtained by the reaction of polyfunctional isocyanates such as tolylene diisocyanate, isophorone diisocyanate, and xylylene diisocyanate with hydroxyl-containing (meth)acrylic acid esters such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate;
Polyfunctional aromatic vinyls such as divinylbenzene;
Examples include:

In particular, trifunctional (meth)acrylates such as trimethylolpropane tri(meth)acrylate and pentaerythritol tri(meth)acrylate, tetrafunctional (meth)acrylates such as pentaerythritol tetra(meth)acrylate and ditrimethylolpropane tetra(meth)acrylate, and hexafunctional (meth)acrylates such as dipentaerythritol hexa(meth)acrylate are preferred.

When a photosensitive resin composition contains a crosslinking agent, it may contain only one type of crosslinking agent or two or more types. If the photosensitive resin composition contains a crosslinking agent, the amount can be appropriately set according to the purpose and application. For example, the amount of crosslinking agent can typically be 30 to 70 parts by mass, preferably 40 to 60 parts by mass, per 100 parts by mass of the photosensitive resin.

(Other additives)
Depending on the purpose and required properties, the photosensitive resin composition may also contain components such as fillers, binder resins other than the polymers mentioned above, acid generators, heat resistance improvers, developing aids, plasticizers, polymerization inhibitors, ultraviolet absorbers, antioxidants, matting agents, defoamers, leveling agents, antistatic agents, dispersants, slip agents, surface modifiers, oscillating agents, oscillating aids, silane coupling agents, and polyvalent phenol compounds.

[Application]
A patterned film can be obtained by forming a film using the above-described photosensitive resin composition, and then exposing and developing the film to form a pattern. This film can be applied to color filters, black matrices, and the like. In other words, a color filter can be obtained by forming a pattern using a photosensitive resin composition containing a coloring agent. A black matrix can also be obtained by forming a pattern using a photosensitive resin composition containing a light-shielding agent. Then, liquid crystal display devices and solid-state image sensors equipped with color filters and black matrices can be manufactured.
This section describes a typical procedure for forming a pattern.

(Formation of a photosensitive resin film)
For example, the above photosensitive resin composition is applied to any substrate and dried as necessary to first obtain a photosensitive resin film.

The substrate to which the composition is applied is not particularly limited. Examples include glass substrates, silicon wafers, ceramic substrates, aluminum substrates, SiC wafers, GaN wafers, and copper-clad laminates.
The substrate may be an unprocessed substrate or a substrate with electrodes or elements formed on its surface. It may also be surface-treated to improve adhesion.

The method of coating the photosensitive resin composition is not particularly limited. It can be applied by rotary coating using a spinner, spray coating using a spray coater, dipping, printing, roll coating, inkjet, etc.

The photosensitive resin composition applied to the substrate is typically dried by heat treatment using a hot plate, hot air, oven, etc. The heating temperature is usually 80 to 140°C, preferably 90 to 120°C. The heating time is usually 30 to 600 seconds, preferably 30 to 300 seconds.

The thickness of the photosensitive resin film is not particularly limited and can be adjusted as appropriate depending on the pattern to be ultimately obtained, but it is usually 0.5 to 10 μm, preferably 1 to 5 μm. The film thickness can be adjusted by the solvent content in the photosensitive resin composition and the application method.

(exposure)
Exposure is typically performed by irradiating a photosensitive resin film with active light through a suitable photomask.

Examples of active light include X-rays, electron beams, ultraviolet rays, and visible light. In terms of wavelength, light with a range of 200 to 500 nm is preferred. In terms of pattern resolution and handling ease, the light source is preferably the g-line, h-line, or i-line of a mercury lamp, with the i-line being particularly preferred. Alternatively, two or more light rays may be mixed and used. As the exposure apparatus, a contact aligner, mirror projection, or stepper is preferred.
The amount of light used for exposure can be adjusted as appropriate depending on the amount of photosensitive agent in the photosensitive resin film, but it is typically around 100 to 500 mJ/ ^cm² .

Furthermore, if necessary, the photosensitive resin film may be heated again after exposure (post-exposure baking). The temperature is, for example, 70 to 150°C, preferably 90 to 120°C. The time is, for example, 30 to 600 seconds, preferably 30 to 300 seconds. Post-exposure baking promotes the reaction by radicals generated from the photoradical polymerization initiator, further accelerating the curing reaction.

(developing)
A pattern can be obtained by developing an exposed photosensitive resin film with a suitable developer, and a substrate with the pattern can be manufactured.
The photosensitive resin film made from the photosensitive resin composition containing the polymer solution of this embodiment exhibits excellent adhesion to the substrate, thereby suppressing pattern peeling during the development process.

In the development process, development can be carried out using a suitable developer solution and methods such as immersion, paddle, or rotary spray. Development removes the exposed areas (in the case of positive film) or unexposed areas (in the case of negative film) of the photosensitive resin film, thereby obtaining a pattern.
The type of developer that can be used is not particularly limited. For example, alkaline aqueous solutions and organic solvents can be used.

Examples of specific alkaline aqueous solutions include (i) inorganic alkaline aqueous solutions such as sodium hydroxide, sodium carbonate, sodium silicate, and ammonia; (ii) organic amine aqueous solutions such as ethylamine, diethylamine, triethylamine, and triethanolamine; and (iii) aqueous solutions of quaternary ammonium salts such as tetramethylammonium hydroxide and tetrabutylammonium hydroxide.
The polymer of this embodiment has adjusted alkali solubility and excellent sensitivity, so when using a strongly basic developer such as TMAH (tetramethylammonium hydroxide) solution, the pattern after exposure and development can be made into the designed shape.

Examples of organic solvents include ketone solvents such as cyclopentanone, ester solvents such as propylene glycol monomethyl ether acetate (PGMEA) and butyl acetate, and ether solvents such as propylene glycol monomethyl ether.
The developing solution may contain, for example, water-soluble organic solvents such as methanol or ethanol, or surfactants.

In this embodiment, it is preferable to use an alkaline aqueous solution as the developer, and more preferable to use tetramethylammonium hydroxide, an aqueous sodium carbonate solution, or an aqueous potassium hydroxide solution.
The concentration of the alkaline aqueous solution is preferably 0.01 to 10% by mass, and more preferably 0.5 to 5% by mass.
Through the above process, a pattern can be obtained and a substrate with the pattern can be manufactured, but various processing steps may be performed after development.

For example, after development, the pattern and substrate may be cleaned with a rinsing solution. Examples of rinsing solutions include distilled water, methanol, ethanol, isopropanol, and propylene glycol monomethyl ether. These may be used individually or in combination of two or more.

The resulting pattern may also be heated to ensure sufficient curing. The heating temperature is typically 150 to 400°C, preferably 160 to 300°C, and more preferably 200 to 250°C. The heating time is not particularly limited, but is, for example, in the range of 15 to 300 minutes. This heat treatment can be carried out using a hot plate, an oven, or a heating oven with a temperature programmable. The atmospheric gas used during the heat treatment may be air, or an inert gas such as nitrogen or argon. Heating may also be carried out under reduced pressure.
Figure 1 schematically shows an example of the structure of a liquid crystal display device and/or solid-state image sensor, which includes a color filter and/or black matrix.

A black matrix 11 and a color filter 12 are formed on the substrate 10. A protective film 13 and a transparent electrode layer 14 are provided above the black matrix 11 and color filter 12.

The substrate 10 is typically made of a light-transmitting material, such as glass, polyester, polycarbonate, polyolefin, polysulfone, or a polymer of cyclic olefin. The substrate 10 may also be subjected to corona discharge treatment, ozone treatment, chemical treatment, etc., as needed.
The substrate 10 is preferably made of glass.
The black matrix 11 is composed, for example, of a cured product of a photosensitive resin composition containing a light-shielding agent.

Color filters 12 typically come in three colors: red, green, and blue. Each color filter 12 is composed of a cured photosensitive resin composition containing a coloring agent corresponding to its respective color.

The embodiments of the present invention have been described above, but these are merely examples, and various other configurations can also be adopted.
Further embodiments of the present invention are described below.

[1] A step of preparing a raw material polymer by polymerizing a monomer composition containing a monomer represented by formula (INm) and maleic anhydride in the presence of a thiol group-containing compound with two or more functionalities,
A method for producing a polymer, comprising the step of reacting the aforementioned raw material polymer with a polyfunctional (meth)acrylic compound and/or a monofunctional methacrylic compound in the presence of a basic catalyst to obtain a polymer.
(In formula (INm), ^R1 and ^R2 are each independently a hydrogen atom or an organic group having 1 to 30 carbon atoms.)

[2] A step of preparing a raw material polymer by polymerizing a monomer composition containing a monomer represented by formula (INm) and maleic anhydride in the presence of a thiol group-containing compound with two or more functionalities,
A step of preparing a polymer precursor by reacting the aforementioned raw material polymer with a polyfunctional (meth)acrylic compound and/or a monofunctional methacrylic compound in the presence of a basic catalyst,
A method for producing a polymer, comprising the step of obtaining a polymer by treating the polymer precursor with water in the presence of a basic catalyst.
(In formula (INm), ^R1 and ^R2 are each independently a hydrogen atom or an organic group having 1 to 30 carbon atoms.)

[3] A step of preparing a raw material polymer by polymerizing a monomer composition containing a monomer represented by formula (INm) and maleic anhydride in the presence of a thiol group-containing compound with two or more functionalities,
A step of preparing a polymer precursor by reacting the aforementioned raw material polymer with a polyfunctional (meth)acrylic compound and/or a monofunctional methacrylic compound in the presence of a basic catalyst,
A method for producing a polymer, comprising the step of reacting the aforementioned polymer precursor with an epoxy group-containing (meth)acrylic compound in the presence of a catalyst to obtain a polymer.
(In formula (INm), ^R1 and ^R2 are each independently a hydrogen atom or an organic group having 1 to 30 carbon atoms.)

[4] The method for producing a polymer according to any one of [1] to [3], wherein the thiol group-containing compound with two or more functions is at least one compound selected from formulas (s-1) to (s-21).

[5] A polymer solution containing a polymer obtained by the polymer manufacturing method described in any of [1] to [4].

[6] The polymer solution according to [5], further comprising at least one selected from polyfunctional (meth)acrylic compounds, monofunctional (meth)acrylic compounds, and compounds having a thiol group and an alkoxy group or their oligomers.

[7] A polymer solution according to [5] or [6], used for forming a color filter or black matrix.

[8] A photosensitive resin composition comprising the polymer solution described in [5] or [6] and a photopolymerization initiator.

[9] A cured product of the photosensitive resin composition described in [8].

The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these.

The compounds used in the examples may be indicated by the following abbreviations or trade names.
MA: Maleic anhydride, IN: Indene, MEK: Methyl ethyl ketone, PEMP: Pentaerythritol tetrakis(3-mercaptopropionate), a thiol group-containing compound of the above formula (s-2) (manufactured by SC Organic Chemicals Co., Ltd.)
NB: 2-norbornene, 4-HBA: 4-hydroxybutyl acrylate, A-TMM-3LM-N: a mixture of the following two compounds; the amount of the compound on the left in the mixture, based on gas chromatography measurement, is approximately 57% (manufactured by Shin Nakamura Chemical Industry Co., Ltd.).

GMA: Glycidyl methacrylate/KBM-803: 3-mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd.)

<Synthesis of raw material polymers>
(Synthesis of raw material polymer 1)
In a reaction vessel of appropriate size equipped with a stirrer and condenser, 122.4 g (1.05 mol) of indene, 1376.7 g of methyl ethyl ketone, and 9.70 g (0.042 mol) of dimethyl 2,2'-azobis(2-methylpropionate) were weighed and added, and stirred until dissolved. Next, dissolved oxygen in the system was removed by nitrogen bubbling, and the mixture was heated until the internal temperature reached 80°C. At this point, 103.2 g (1.05 mol) of maleic anhydride was dissolved in 1.30 g of MEK 74, and the solution, from which dissolved oxygen was removed by nitrogen bubbling, was added over 3 hours. Subsequently, the mixture was heated further at 80°C for 4 hours to polymerize the maleic anhydride and indene, thereby preparing a polymerization solution.
The polymerization solution obtained above was added dropwise to 2047.94 g of methanol to precipitate a white solid. The obtained white solid was then washed with another 2047.94 g of methanol and vacuum-dried at 120°C to obtain 320.1 g of a polymer (raw material polymer 1) comprising structural units derived from indene and structural units derived from maleic anhydride.
The obtained polymer was measured using gel permeation chromatography (GPC), and the weight-average molecular weight Mw was 9248, with a polydispersity (weight-average molecular weight Mw) / (number-average molecular weight Mn) of 2.31.

(Synthesis of raw material polymer 2)
In a reaction vessel of appropriate size equipped with a stirrer and condenser, 122.4 g (1.05 mol) of indene, 131.0 g of methyl ethyl ketone, and 3.73 g (0.016 mol) of dimethyl 2,2'-azobis(2-methylpropionate) were weighed and added, and stirred until dissolved. Next, dissolved oxygen in the system was removed by nitrogen bubbling, and the mixture was heated until the internal temperature reached 55°C. At this point, a solution containing 103.2 g (1.05 mol) of maleic anhydride and pentaerythritol tetrakis(3-mercaptopropionate) (PEMP, 20.58 g, 0.042 mol) dissolved in 131.02 g of MEK, from which dissolved oxygen was removed by nitrogen bubbling, was added over 3 hours. Subsequently, the mixture was heated at 55°C for another 3 hours to polymerize the maleic anhydride and indene, thereby preparing a polymerization solution.
The polymerization solution obtained above was added dropwise to 2047.94 g of methanol to precipitate a white solid. The obtained white solid was then washed with another 2047.94 g of methanol and vacuum-dried at 120°C to obtain 315.0 g of a polymer (raw material polymer 2) comprising structural units derived from indene and structural units derived from maleic anhydride.
The obtained polymer was measured using gel permeation chromatography (GPC), and the weight-average molecular weight Mw was 8284, with a polydispersity (weight-average molecular weight Mw) / (number-average molecular weight Mn) of 1.41.

[Structural analysis of raw material polymer 2]
The synthesis of raw material polymer 2 begins with the monomer and PEMP dissolved in the solvent at the start of the reaction, after which the reaction proceeds to produce the polymer. Analysis of the reaction solution and the resulting polymer yielded the following results.

(a) Analysis of the reaction solution GPC measurement of the reaction solution before reprecipitation and purification did not show a peak for PEMP alone. In other words, it was confirmed that no PEMP remained in the reaction solution. In addition, GC (gas chromatography) measurement of the reaction solution before reprecipitation and purification showed that the peaks for indene and maleic anhydride in the reaction solution after the reaction were reduced compared to before the reaction, confirming that indene and maleic anhydride reacted and formed a polymer.
The measurement conditions for gas chromatography were as follows:
・GC device: GC-2030 (Shimadzu Corporation)
Carrier gas: N2
• Detector: Flame ionization (FID) detector, FID temperature: 300°C
• Column: SH-RXi-1HT, inner diameter 0.25, length 30 m, film thickness 0.25 μm (Shimadzu GLC Corporation)
• Evaporation chamber temperature: 210°C
Column flow rate: 0.64 mL/min
Column heating conditions: Hold at 50°C for 5 minutes, heat up to 300°C at a rate of 20°C/min, hold at 300°C for 10 minutes.

(b) Analysis of the polymer GPC analysis of the polymer after reprecipitation and purification did not reveal any peaks for PEMP, indene, or maleic anhydride. In other words, it was confirmed that no PEMP, indene, or maleic anhydride remained in the polymer.
The amount of sulfur in the obtained raw material polymer 2 was confirmed by elemental analysis using flask combustion and ion chromatography, confirming the presence of sulfur in raw material polymer 2. Furthermore, GPC measurement of the reaction solution did not show a peak for PEMP alone, indicating that no unreacted PEMP remained, thus confirming that PEMP was incorporated into raw material polymer 2.

The elemental analysis method is as follows:
- Test item: Total sulfur determination by flask combustion to ion chromatography - Test method: Flask combustion to ion chromatography (1) Complete combustion of approximately 50 mg of the sample in a sealed flask substituted with oxygen.
(2) The generated gas is collected in the hydrogen peroxide absorption solution that has been added to the flask beforehand, and the volume is adjusted to 50 ml to be used as the test solution.
(3) The sample solution and standard solution are introduced into the ion chromatograph, the concentration of sulfate ions is determined by the calibration curve method, and the amount of sulfur contained in the sample is calculated.
- Equipment used: DIONEX ICS-3000 ion chromatograph

[Confirmation of the thioether structure contained in raw material polymer 2]
^13C -NMR measurements of elemental PEMP, represented by the following chemical formula, revealed a peak a originating from carbon a at approximately 19.0 ppm and a peak b originating from carbon b at approximately 62.0 ppm.

In ^13C -NMR analysis of the raw material polymer 2 synthesized using PEMP, a peak b derived from carbon b was observed at approximately 62.0 ppm. GPC analysis of the reaction solution did not reveal a peak for PEMP alone, indicating that no unreacted PEMP remained, thus confirming that PEMP was incorporated into the raw material polymer 2.

Furthermore, in the ^13C -NMR measurement of raw material polymer 2, the peak a derived from carbon a was not observed, and instead, a peak c corresponding to a thioether (R-S-R') appeared around 28 ppm. Since the integral value of this peak c is approximately twice the integral value of peak b, it was determined that raw material polymer 2 has a skeleton with a thioether group as shown below, and the thiol group had disappeared. It is thought that the polymer of the example synthesized using raw material polymer 2 has a similar skeleton.

13. The conditions for ^13C -NMR measurement are as follows:
(Test conditions) The measurement sample was prepared by adding the measurement solvent to the weighed sample to adjust the concentration, and then pouring the specified amount into an NMR measurement sample tube.
• Measurement device: JEOL JNM-ECA400 superconducting FT-NMR spectrometer • Resonance frequency: 100.53 MHz
・Measurement nucleus: ^13C
• Measurement method: NNE measurement (inverse gate decoupling method)
Pulse width: 3.83 μsec
Pulse repetition waiting time: 30s
• Total number of measurements: 4096 • Measurement temperature: Room temperature • Measurement solvent: DMSO- _d6 (Deuterated Dimethyl Sulfoxide)
• Sample concentration: 20% (w/v)

^13. Based on 13¹¹C-NMR measurements, the amount of PEMP incorporated into the raw material polymer 2 relative to the total amount of indene and maleic anhydride in the raw material polymer 2 was calculated to be 2.2 mol% using the following calculation method.

[Method for calculating the amount of PEMP (mol%) in raw material polymer 2]
First, the amount of PEMP introduced into the raw polymer 2 is calculated from the peak integral value of 60 ppm - 64 ppm, which corresponds to peak b (4C) of PEMP.
Next, by subtracting the peak integral value corresponding to the PEMP peak bd (4C) that overlaps with the peak integral value (the integral value of PEMP peak b = the integral value of PEMP peak d) from the peak integral value of 170 ppm - 175 ppm, the amount of MA in raw material polymer 2 corresponding to the maleic anhydride (MA) peak e (2C) below is calculated.

Then, the amount of IN in the raw polymer 2 is calculated from the peak integral values of 125 ppm to 142 ppm, which correspond to the aromatic ring (6C portion) of indene (IN).
Based on the above, the amount of PEMP incorporated into raw material polymer 2 (mol%) relative to the total amount of indene and maleic anhydride in raw material polymer 2 is calculated using the formula: "(Amount of PEMP in raw material polymer 2) ÷ ((Amount of MA in raw material polymer 2) + (Amount of IN in raw material polymer 2))".

(Synthesis of raw material polymer 3)
In a reaction vessel equipped with a stirrer, condenser, and dropping funnel, 602.56 g of a 75% toluene solution of 2-norbornene (equivalent to 451.92 g of 2-norbornene, 4.8 mol), maleic anhydride (MAN, 470.69 g, 4.8 mol), and 2281.74 g of methyl ethyl ketone (MEK) were added and stirred until dissolved. Next, dissolved oxygen in the system was removed by nitrogen bubbling, and the system was heated until the internal temperature reached 80°C. Then, a solution of 2,2'-dimethyl azobisisobutyrate (Wako Pure Chemical Industries, Ltd., trade name: V-601, 44.21 g, 0.19 mol) and PEMP (93.82 g, 0.19 mol) dissolved in 193.4 g of MEK was added over 1 hour. The reaction was then continued at 80°C for 7 hours. The reaction mixture was then cooled to room temperature. The polymerization solution obtained above was added dropwise to 3686.4 g of methanol to precipitate a white solid. The obtained white solid was then washed with another 3686.4 g of methanol and vacuum-dried at 120°C to obtain 910.1 g of a polymer (raw material polymer 4) comprising structural units derived from 2-norbornene and structural units derived from maleic anhydride.
The obtained polymer was measured using gel permeation chromatography (GPC), and the weight-average molecular weight Mw was 3500, while the polydispersity (weight-average molecular weight Mw) / (number-average molecular weight Mn) was 1.62.
[Confirmation of the thioether structure contained in raw material polymer 3]
In ^13C -NMR analysis of the raw material polymer 3 synthesized using PEMP, a peak b derived from carbon b was observed at approximately 62.0 ppm. GPC analysis of the reaction solution showed no peak for PEMP alone, indicating that no unreacted PEMP remained, thus confirming that PEMP was incorporated into the raw material polymer 3.

Furthermore, in the ^13C -NMR measurement of the raw material polymer 3, the peak a originating from carbon a was not observed. Instead, a peak c corresponding to a thioether (R-S-R') appeared around 28 ppm. Since the integral value of this peak c is approximately twice that of peak b, it was determined that the raw material polymer 3 possesses a skeleton with a thioether group as described below, and the thiol group had disappeared. It is also considered that the comparative polymer synthesized using the raw material polymer 3 possesses a similar skeleton.

The amount of sulfur in the obtained polymer was confirmed by elemental analysis using flask combustion and ion chromatography, confirming the presence of sulfur in the polymer. Furthermore, GPC analysis of the reaction solution before methanol addition showed the disappearance of the PEMP-derived peak, confirming that PEMP was incorporated into the polymer.

Elemental analysis revealed that the sulfur content in raw polymer 3 was 2.4 wt%.

<Preparation of Polymer P (polymer solution)>
Polymer P was prepared in each preparation example. Table 1 shows the components used in each preparation example, the amount of each component charged in terms of maleic anhydride (MA), and the amount of each structural unit (mole fraction, mol%) calculated by integral analysis of ^1H -NMR and shown in terms of maleic anhydride (MA).

(Preparation Example 1)
Polymer P1 was prepared by ring-opening the MA units of raw material polymer 1 with a monofunctional (meth)acrylic compound. Details are described below.
First, 18.44 g of MEK was added to 10.00 g of raw polymer 1 (0.047 mol in MA equivalent) to prepare a solution. Next, 9.38 g of 4-HBA (0.065 mol) was added to this solution, followed by 3.00 g of triethylamine (0.030 mol), and the mixture was reacted at 70°C for 6 hours to prepare a reaction solution.
The resulting reaction solution was diluted with MEK and treated with an aqueous citric acid solution to remove the aqueous phase. The polymer was then purified using the reprecipitation method described below.
• Reprecipitation method: The polymer was reprecipitated with an excess amount of water. The polymer powder obtained by reprecipitation was washed with an excess amount of water, and this process was repeated twice. The resulting reaction product was dried at 40°C for 12 hours.
Based on the above, 9.1 g of polymer P1 was obtained by ring-opening the structural units derived from maleic anhydride in raw material polymer 1 with 4-HBA.
The obtained polymer P1 was subjected to GPC measurement to determine its weight-average molecular weight and polydispersity. The results are shown in Table 1.
Furthermore, GPC analysis of polymer P1 confirmed the disappearance of the peak of the monofunctional (meth)acrylic compound used. This confirmed that the obtained polymer P1 did not contain any unreacted monofunctional (meth)acrylic compound.

(Preparation Example 2)
Except for replacing raw material polymer 1 in Preparation Example 1 with raw material polymer 2, the same procedure was followed to obtain 7.5 g of polymer P2, in which the structural units derived from maleic anhydride in raw material polymer 2 were ring-opened with 4-HBA.
The obtained polymer P2 was subjected to GPC measurement to determine its weight-average molecular weight and polydispersity. The results are shown in Table 1.
Furthermore, GPC analysis of polymer P2 confirmed the disappearance of the peak of the monofunctional (meth)acrylic compound used. This confirmed that the obtained polymer P2 did not contain any unreacted monofunctional (meth)acrylic compound.

(Preparation Example 3)
A resin mixture containing polymer P3, which was obtained by ring-opening the MA units of raw material polymer 1 with a trifunctional (meth)acrylic compound, a monofunctional (meth)acrylic compound, and water, was prepared. The details are described below.
First, a solution was prepared by adding 99.71 g of MEK to 60.00 g (0.280 mol in MA equivalent) of the raw material polymer. Next, 38.75 g of A-TMM-3LM-N was added to this solution, followed by 18.00 g (0.178 mol) of triethylamine, and the mixture was reacted at 70°C for 2 hours. Subsequently, 56.27 g (0.390 mol) of 4-HBA was added, and the mixture was reacted at 70°C for 4 hours to prepare the reaction solution.
Next, without any post-treatment of the resulting reaction solution, 3.00 g (0.167 mol) of water was added to the reaction solution, and the mixture was reacted at 70°C for 2 hours. The resulting reaction solution was diluted with MEK, and the aqueous phase was removed from the reaction solution by treating it with aqueous formic acid solution and aqueous citric acid solution. Further liquid-liquid extraction and subsequent solvent replacement were performed according to the following procedure.
• Liquid-liquid extraction: The reaction solution was diluted with MEK, then water was added and treated to remove the aqueous phase from the reaction solution. This procedure was then repeated once more.
Solvent Replacement: The solvent was removed from the resulting reaction mixture under reduced pressure at 50°C using a rotary evaporator. The solvent removal operation was stopped when the solid content concentration of the polymer solution was confirmed to be 27 ± 2% by mass as measured by a heat-drying type moisture meter. Then, PGMEA was added to bring the solid content concentration to 18% by mass and mixed until homogeneous. The same procedure was repeated two more times to remove the solvent under reduced pressure at 50°C, adjust the solid content concentration to 27 ± 2% by mass as measured by a heat-drying type moisture meter, and then add PGMEA to bring the solid content concentration to 18% by mass and mix until homogeneous. Then, the solvent was removed or PGMEA was added and stirred until homogeneous to bring the solid content concentration to 30 ± 3% by mass. Through the above operations, the solvent used in the reaction was removed and replaced with PGMEA.
As a result, polymer P3 was obtained by ring-opening the structural units derived from maleic anhydride in the raw material polymer 1 with A-TMM-3LM-N, 4-HBA, and water, and polymer solution 3 containing residual (free) A-TMM-3LM-N and residual (free) 4-HBA was obtained.
The obtained polymer solution 3 was analyzed by gel permeation chromatography to determine the amounts of polymer P3, free polyfunctional (meth)acrylic compounds, and free monofunctional (meth)acrylic compounds contained in the composition, as well as the weight-average molecular weight and polydispersity of polymer P3. The results are shown in Table 1. The amount of free (meth)acrylic compounds is expressed as the ratio (%) of the peak area of the free (meth)acrylic compounds to the peak area of polymer P3 in the gel permeation chromatography (GPC) chart of the resin mixture.
The measurement conditions for gel permeation chromatography are as follows:
The GPC measurement device used was the HLC-8320GPC EcoSEC from Tosoh Corporation. The column temperature was set to 40.0°C and the pump flow rate to 0.350 mL/min.
• Peak position (holding time)
- Polymer P3: Peak detected before 20 minutes (a peak with a shorter retention time and higher molecular weight than A-TMM-3LM-N and 4-HBA)
-A-TMM-3LM-N: sum of two peaks at 20.0–20.6 min and 20.6–21.5 min. -4-HBA: 21.7–22.4 min. Measurement conditions: Analyzed using a differential refractive index detector (RI detector).

(Preparation Example 4)
Except for changing raw material polymer 1 to raw material polymer 2 in preparation example 3, the procedure is the same as in preparation example 3.
A polymer P4 was obtained by ring-opening the structural units derived from maleic anhydride in the raw material polymer 2 with A-TMM-3LM-N, 4-HBA, and water, and a polymer solution 4 containing residual (free) A-TMM-3LM-N and residual (free) 4-HBA was obtained.
The obtained polymer solution 4 was analyzed by gel permeation chromatography to determine the amounts of polymer P4, free polyfunctional (meth)acrylic compounds, and free monofunctional (meth)acrylic compounds contained in the composition, as well as the weight-average molecular weight and polydispersity of polymer P4. The results are shown in Table 1. The amount of free (meth)acrylic compounds is expressed as the ratio (%) of the peak area of the free (meth)acrylic compounds to the peak area of polymer P4 in the gel permeation chromatography (GPC) chart of the resin mixture.
The measurement conditions for gel permeation chromatography are as follows:
The GPC measurement device used was the HLC-8320GPC EcoSEC from Tosoh Corporation. The column temperature was set to 40.0°C and the pump flow rate to 0.350 mL/min.
• Peak position (holding time)
- Polymer P4: Peak detected before 20 minutes (a peak with a shorter retention time and higher molecular weight than A-TMM-3LM-N and 4-HBA)
-A-TMM-3LM-N: sum of two peaks at 20.0–20.6 min and 20.6–21.5 min. -4-HBA: 21.7–22.4 min. Measurement conditions: Analyzed using a differential refractive index detector (RI detector).

(Preparation Example 5)
Polymer solution 5 was prepared by mixing the additives listed in Table 1 with the polymer solution 4 obtained in Preparation Example 4, in the amounts indicated in "Additive Amount" in Table 1. Here, the amount of additive was mixed in weight percent relative to the solid content (polymer P4, polyfunctional (meth)acrylic compound) in polymer solution 4.

(Preparation Example 6)
Polymer P6 was prepared by ring-opening the MA units of raw material polymer 1 with a trifunctional (meth)acrylic compound (A-TMM-3LM-N) and a monofunctional (meth)acrylic compound (4-HBA), and then reacting them with an epoxy group-containing (meth)acrylic compound (GMA). The details are described below.
First, a solution was prepared by adding 102.63 g of MEK to 160 g of the raw polymer (0.280 mol in MA equivalent). Next, 58.12 g of A-TMM-3LM-N was added to this solution, followed by 18.00 g (0.178 mol) of triethylamine, and the mixture was reacted at 70°C for 2 hours. Subsequently, 27.01 g (0.187 mol) of 4-HBA was added, and the mixture was reacted at 70°C for 4 hours. Finally, 13.31 g (0.094 mol) of GMA was added, and the mixture was reacted at 70°C for 4 hours to prepare the reaction solution.
The prepared reaction solution was diluted with MEK and treated with an aqueous formic acid solution to remove the aqueous phase. The polymer was then purified using the following procedure.
- The polymer was reprecipitated with an excess amount of toluene.
The polymer powder obtained by reprecipitation was washed twice with an excess amount of toluene.
The polymer powder, after being washed twice as described above, was washed three times with an excess amount of water.
The resulting reaction product was dried at 40°C for 16 hours.
Based on the above, 32.0 g of polymer P6 was obtained by ring-opening the structural units derived from maleic anhydride in raw material polymer 1 with A-TMM-3LM-N and 4-HBA, and reacting them with GMA.

GPC analysis of polymer P6 confirmed the disappearance of peaks for the polyfunctional (meth)acrylic compound, monofunctional (meth)acrylic compound, and epoxy group-containing (meth)acrylic compound used. This confirmed that the resulting polymer P6 did not contain unreacted (meth)acrylic compounds, (meth)acrylic compounds without hydroxyl groups, or unreacted epoxy group-containing (meth)acrylic compounds.

(Preparation Example 7)
Except for replacing raw material polymer 1 with raw material polymer 2 in Preparation Example 6, the same procedure was followed to obtain 25.1 g of polymer P7 by ring-opening the structural units derived from maleic anhydride in raw material polymer 2 with A-TMM-3LM-N and 4-HBA, and reacting them with GMA.

GPC analysis of polymer P7 confirmed the disappearance of peaks for the polyfunctional (meth)acrylic compound, monofunctional (meth)acrylic compound, and epoxy group-containing (meth)acrylic compound used. This confirmed that the resulting polymer P7 did not contain unreacted (meth)acrylic compounds, (meth)acrylic compounds without hydroxyl groups, or unreacted epoxy group-containing (meth)acrylic compounds.

(Preparation Example 8)
Except for replacing the raw material polymer 1 in Preparation Example 1 with 10 g of raw material polymer 3 (0.052 mol in MA equivalent), the same procedure as in Preparation Example 1 was followed to obtain 8.7 g of polymer P8, in which the structural units derived from maleic anhydride in raw material polymer 3 were ring-opened with 4-HBA.
The obtained polymer P8 was subjected to GPC measurement to determine its weight-average molecular weight and polydispersity. The results are shown in Table 1.
Furthermore, GPC analysis of polymer P8 confirmed the disappearance of the peak of the monofunctional (meth)acrylic compound used. This confirmed that the obtained polymer P8 did not contain any unreacted monofunctional (meth)acrylic compound.

(Preparation Example 9)
(Polymer synthesis)
Polymer P9 was prepared by ring-opening the MA units of raw material polymer 3 with a monofunctional (meth)acrylic compound (HEMA), and then reacting it with an epoxy group-containing (meth)acrylic compound (GMA). The details are described below.
First, a solution was prepared by adding 111.43 g of MEK to 360 g of the raw polymer (0.312 mol in MA equivalent). Next, 25.38 g of HEMA (0.195 mol) was added to this solution, followed by 6.00 g of triethylamine (0.059 mol), and the mixture was reacted at 70°C for 6 hours. Subsequently, 13.31 g of GMA (0.094 mol) was added, and the mixture was reacted at 70°C for 4 hours to prepare the reaction solution.
The prepared reaction solution was diluted with MEK and treated with an aqueous formic acid solution to remove the aqueous phase. The polymer was then purified using the following procedure.
- The polymer was reprecipitated with an excess amount of water.
The polymer powder obtained by reprecipitation was washed twice with an excess amount of water.
The resulting reaction product was dried at 40°C for 16 hours.
Based on the above, 35.1 g of polymer P9 was obtained by ring-opening the structural units derived from maleic anhydride in the raw material polymer with HEMA and reacting them with GMA.
GPC analysis of polymer P9 confirmed the disappearance of the peaks of the monofunctional (meth)acrylic compound and the epoxy group-containing (meth)acrylic compound used. This confirmed that the obtained polymer P9 did not contain any unreacted (meth)acrylic compounds or epoxy group-containing (meth)acrylic compounds.

(Preparation Example 10)
Polymer P10 was prepared by ring-opening the MA units of raw material polymer 2 with trifunctional (meth)acrylic compounds, monofunctional (meth)acrylic compounds, and water. Details are described below.
First, a solution was prepared by adding 99.71 g of MEK to 60.00 g of raw polymer 2 (0.280 mol in MA equivalent). Next, 38.75 g of A-TMM-3LM-N was added to this solution, followed by 18.00 g (0.178 mol) of triethylamine, and the mixture was reacted at 70°C for 2 hours. Subsequently, 56.27 g (0.390 mol) of 4-HBA was added, and the mixture was reacted at 70°C for 4 hours to prepare the reaction solution.
Next, without any post-treatment of the resulting reaction solution, 3.00 g (0.167 mol) of water was added to the reaction solution, and the mixture was reacted at 70°C for 2 hours.
The prepared reaction solution was diluted with MEK and treated with an aqueous formic acid solution to remove the aqueous phase. The polymer was then purified using the following procedure.
The polymer was reprecipitated with an excess amount of toluene.
The polymer powder obtained by reprecipitation was washed twice with an excess amount of toluene.
The polymer powder, after being washed twice as described above, was washed three times with an excess amount of water.
The resulting reaction product was dried at 40°C for 16 hours.
Based on the above, 32.4 g of polymer P10 was obtained by ring-opening the structural units derived from maleic anhydride in raw material polymer 2 with A-TMM-3LM-N, 4-HBA, and plenty of water.
GPC analysis of polymer P10 confirmed the disappearance of peaks for the polyfunctional (meth)acrylic and monofunctional (meth)acrylic compounds used. This confirmed that the obtained polymer P10 did not contain any unreacted (meth)acrylic compounds or (meth)acrylic compounds without hydroxyl groups.

(Evaluation of physical properties)
The acid value and double bond equivalent of polymer P synthesized in the examples and comparative examples were measured by the method described below.

(Acid value)
The acid value of the polymer was measured by the following method.
Approximately 50 mg of polymer and approximately 5 mg of dimethyl terephthalate as an internal standard were weighed and dissolved in DMSO-d6. This solution was subjected to ^1H -NMR measurement using a JNM-AL300 nuclear magnetic resonance spectrometer ( ^JEOL ). The amount of carboxyl groups was determined from the integral value of the H peak (around 12.4 ppm) of the carboxyl group (-COOH) of the polymer, using the integral value of the 4H peak (around 8.1 ppm) of the phenyl group of the dimethyl terephthalate internal standard as a reference. The acid value (mgKOH/g) could then be calculated from this amount. A higher acid value indicates a greater amount of carboxyl groups per unit mass of polymer.
The results are shown in Table 1. An acid value of 70 gKOH/g or higher indicates that the polymer contains sufficient carboxyl groups necessary for adequate development.

(double bond equivalent)
The double bond equivalents of the polymer were measured by the following method.
Similar to the acid value measurement method described above, ^1H -NMR measurements were performed. The amount of acryloyl groups in the polymer (mol/g) was calculated from the integral ratio of the signal originating from the acryloyl group (5.6–5.8 ppm, 3H) and the signal of the phenyl group of the internal standard (8.1 ppm, 4H) in the obtained spectral chart. The amount of methacryloyl groups in the polymer (mol/g) was calculated from the integral ratio of the signal originating from the methacryloyl group (5.6–5.8 ppm, 2H) and the signal of the phenyl group of the internal standard (8.1 ppm, 4H). Here, the signal originating from the methacryloyl group at 6.0–6.1 ppm was minute and overlapped with the acryloyl group signal, so it was calculated as the signal of the acryloyl group. The amount of double bonds (mol/g) was calculated from the sum of the acryloyl groups (mol/g) and methacryloyl groups (mol/g) in the calculated polymer, and the double bond equivalent (g/mol) was then calculated from the double bond amount.
The results are shown in Table 1. A smaller double bond equivalent value indicates a larger amount of C=C double bonds per unit mass of polymer.

(Examples 1-5, Comparative Examples 1-5)
In each example and comparative example, the following items were evaluated.
<Evaluation>
[Alkaline dissolution rate of polymer solutions]
Polymers P1, P2, and P6-10 obtained in Preparation Examples 1, 2, and 6-10 were dissolved in propylene glycol monomethyl ether acetate (PGMEA) to prepare a solution with a solid content of 30% by mass.
Next, the above solution or the polymer solutions 3 to 5 obtained in Preparation Examples 3 to 5 were spin-coated onto the wafer, the PGMEA was dried, and then a resin film with a thickness of approximately 2 μm was fabricated by pre-baking at a temperature of 100°C for 2 minutes.
The resin film, along with the wafer, was immersed in a 2% sodium carbonate aqueous solution at 23°C, and the dissolution rate of the resin film was measured.
The dissolution rate was calculated by visually observing the immersed wafer, measuring the time it took for the resin film to dissolve and the interference pattern to disappear, and then dividing the film thickness by that time. The results are shown in Table 2. If the alkali dissolution rate is 100 nm/s or higher, the material can be used without problems as a photosensitive material. In particular, a rate of 200 nm/s or higher can be considered especially good.

[Sensitivity evaluation of photosensitive resin composition 1 (exposure amount at which the residual film rate is 95% or more)]
First, a photosensitive resin composition was obtained by dissolving the following components in propylene glycol monomethyl ether acetate (PGMEA) so that the total solids content concentration was 30% by mass.
- Polymers P1, P2, P6-10 (polymers P1, P2, P6-10 from Preparation Examples 1, 2, and 6-10) or polymer solutions 3-5 (polymer solutions 3-5 obtained in Preparation Examples 3-5): 100 parts by mass (Here, polymer solutions 3-5 were weighed so that the solid content (total amount of polymer P3 or P4 and the polyfunctional (meth)acrylic compound, and the total amount including additives if any) was 100 parts by mass.)
- Polyfunctional acrylate (dipentaerythritol hexaacrylate, manufactured by Shin-Nakamura Chemical Industry Co., Ltd., A-DPH): 50 parts by mass - Photopolymerization initiator (manufactured by BASF, Ingacure OXE01): 5 parts by mass - Adhesion aid (manufactured by Shin-Etsu Chemical Co., Ltd., KBM-403): 1 part by mass - Surfactant (manufactured by DIC Corporation, F-556): 0.5 parts by mass

The obtained photosensitive resin composition was rotary coated onto a 3-inch silicon wafer treated with HMDS (Hexamethyldisilazane), and baked on a hot plate at 100°C for 120 seconds to obtain a thin film A with a thickness of approximately 3.0 μm (±0.3 μm).
This thin film A was exposed to g+h+i rays at an exposure dose of 100 mJ/cm² using a Canon g+h+i-ray mask aligner (PLA-501F) via a photomask having a light-shielding rate of ¹ to 100%.
After exposure, the thin film was developed in a 2.0% by mass sodium carbonate aqueous solution at 23°C for 60 seconds (immersed together with the wafer) to obtain thin films B exposed and developed at exposure levels of 1 to 100 mJ/ ^cm² .
The residual film percentage was calculated from the film thicknesses of thin films A and B obtained by the above method using the following formula.
Residual film percentage (%) = (Thickness of thin film B at each exposure dose / Thickness of thin film Af) × 100
The exposure dose at which a residual film rate of 95% or more was determined as the sensitivity of each photosensitive resin composition. The results are shown in Table 1. If the exposure dose at which a residual film rate of 95% or more is 20 mJ/ ^cm² or less, the sensitivity can be considered good, and if it is 15 mJ/ ^cm² or less, the sensitivity can be considered particularly good.

[Sensitivity evaluation of resin composition 2 (residual film rate after exposure at low exposure dose)]
(Residual film percentage at an exposure dose of 5 mJ/ ^cm² )
The photosensitive resin composition prepared in Sensitivity Evaluation 1 described above was rotary coated onto a 3-inch silicon wafer treated with HMDS (Hexamethyldisilazane), and baked on a hot plate at 100°C for 120 seconds to obtain a thin film A with a thickness of 3.0 μm (±0.3 μm).
This thin film A was exposed to g+h+i rays at an exposure dose of 5 mJ/cm² using a Canon g+h+i-ray mask aligner (PLA-501F) via a photomask having a light-shielding rate of 1 to ¹⁰⁰ %.
After exposure, the thin film was developed in a 2.0% by mass sodium carbonate aqueous solution at 23°C for 60 seconds (immersed together with the wafer) to obtain thin film B.
The residual film percentage was calculated from the film thicknesses of thin films A and B obtained by the above method using the following formula.
Residual film percentage (%) = (Thickness of thin film B at each exposure dose / Thickness of thin film A) × 100

(Residual film percentage at an exposure dose of 10 mJ/ ^cm² )
The photosensitive resin composition prepared in Sensitivity Evaluation 1 described above was rotary coated onto a 3-inch silicon wafer treated with HMDS (Hexamethyldisilazane), and baked on a hot plate at 100°C for 120 seconds to obtain a thin film A with a thickness of 3.0 μm (±0.3 μm).
This thin film A was exposed to g+h+i rays at an exposure dose of 10 mJ/cm² using a Canon g+h+i-ray mask aligner (PLA-501F) through a photomask having a light-shielding rate of ¹ to 100%.
After exposure, the thin film was developed in a 2.0% by mass sodium carbonate aqueous solution at 23°C for 60 seconds (immersed together with the wafer) to obtain thin film B.
The residual film percentage was calculated from the film thicknesses of thin films A and B obtained by the above method using the following formula.
Residual film percentage (%) = (Thickness of thin film B at each exposure dose / Thickness of thin film A) × 100
If the residual film rate at an exposure dose of 10 mJ/ ^cm² is 50% or more, it can be used without problems as a photosensitive material.

[Alkali dissolution rate of photosensitive resin composition (2.0% by mass sodium carbonate aqueous solution)]
The photosensitive resin composition prepared in Sensitivity Evaluation 1 described above was spin-coated onto a wafer using the above solution, the PGMEA was dried, and then the film was pre-baked at 100°C for 2 minutes to produce a resin film with a thickness of approximately 2 μm.
The resin film, along with the wafer, was immersed in a 2% sodium carbonate aqueous solution at 23°C, and the dissolution rate of the resin film was measured.
The dissolution rate was calculated by visually observing the immersed wafer, measuring the time it took for the resin film to dissolve and the interference pattern to disappear, and then dividing the film thickness by that time. The results are shown in Table 1. If the alkali dissolution rate is 200 nm/s or higher, it can be used without problems as a photosensitive material; if it is 300 nm/s or higher, it can be considered to have good developability; and if it is 500 nm/s or higher, it can be considered to have particularly good developability.

[Yellow Index]
The photosensitive resin composition prepared in Sensitivity Evaluation 1 described above was rotary coated onto Eagle XG glass (manufactured by Corning, 0.5 mm thick) and baked on a hot plate at 100°C for 120 seconds to obtain a thin film with a thickness of approximately 3.0 μm (±0.1 μm).
This thin film was exposed to g+h+i rays using a Canon g+h+i-ray mask aligner (PLA-600F) at an exposure dose of 100 mJ/ ^cm² .
After exposure, the thin film was developed in a 2.0% by mass sodium carbonate aqueous solution at 23°C for 60 seconds (immersed together with the wafer) to obtain a thin film exposed and developed with an exposure dose of 100 mJ/ ^cm² .
The thin film was heat-treated at 230°C for 30 minutes under air conditions. After the thin film was cooled under air conditions at room temperature, it was heat-treated again at 230°C for 30 minutes under air conditions. The same procedure was repeated, and the heat treatment under air conditions for 30 minutes was performed a total of three times.
The yellow index (YI) of the thin film obtained by the above method was measured three times at different measurement points using a colorimeter CR-5 (Konica Minolta), and the average value was taken as the YI value. The measurement type was transmission measurement, and 100% calibration was performed using uncoated Eagle XG glass (Corning, 0.5 mm thick). The results are shown in Table 1. The lower the yellow index, the better the heat discoloration resistance. A value of 2.0 or less can be used without problems as a photosensitive resin for black matrix production, and a value of 1.50 or less can be considered to have good heat discoloration resistance.

The results of the developability and sensitivity evaluations are shown in Table 2.

The photosensitive resin composition of the example exhibited a good alkaline dissolution rate and, therefore, excellent developability. The photosensitive resin composition of the example required an exposure dose of 20 mJ/ ^cm² or less to achieve a residual film rate of 95% or more. In other words, it cured at a low exposure dose and had high sensitivity. Therefore, the photosensitive resin composition of the example had a good balance of high developability, high sensitivity, and a low yellow index.

<Creating a color filter>
To the photosensitive resin compositions prepared in Examples 1 to 5, an appropriate amount of pigment dispersion NX-061 (manufactured by Dainichi Seika Kogyo Co., Ltd., green) was added to prepare a colored photosensitive resin composition.
By forming this film on a substrate and then performing processes such as exposure and alkaline development, we were able to create a green color filter.
Furthermore, instead of NX-061, the company's own NX-053 (blue) and NX-032 (red) were used as pigment dispersions to form blue or red color filters.

<Creation of the Black Matrix>
To the photosensitive resin compositions prepared in Examples 1 to 5, an appropriate amount of carbon black dispersion NX-595 (manufactured by Dainichi Seika Kogyo Co., Ltd.) was added to prepare a black photosensitive resin composition.
By depositing this onto a substrate and performing processes such as exposure and alkaline development, a black matrix could be formed.

10 Substrate 11 Black matrix 12 Color filter 13 Protective film 14 Transparent electrode layer

Claims (11)

A polymer having a structure represented by formula (P) ,
(In equation (P),
m is 0,
n is an integer between 1 and 6.
p is greater than 0, q is greater than 0, and r is 0.
p represents the molar content of A, q represents the molar content of B, and p + q = 1.
X is hydrogen,
Y is an organic group having a thioether group, which is a 1-6 valent organic group derived from at least one selected from two or more thiol group-containing compounds represented by formula (s-1) to (s-21), and the organic group having the thioether group is bonded to the structural unit in [ ]n via the thioether group (*-S-* (* is a bond)) derived from the thiol group-containing compound,
A represents a structural unit expressed by formula (IN),
B includes at least one structural unit selected from the structural units represented by formula (5), formula (6), formula (8), and formula (9) ,
The structural units A and B are arranged randomly or alternately .
(In formula (IN), ^R1 and ^R2 are each independently a hydrogen atom or an organic group having 1 to 30 carbon atoms.)
(In equations (5), (6), (8), and (9),
R ^p represents a group containing two or more (meth)acryloyl groups,
R ^s represents a group containing one (meth)acryloyl group,
Z is a group containing one or more (meth)acryloyl groups,
Q is a hydrogen atom, or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms.
X represents an oxygen atom, a substituted or unsubstituted alkylene group with 1 to 4 carbon atoms,
If Q is the alkyl group and X is the alkylene group, Q and X may condense to form a cyclic group.
The polymer according to claim 1, wherein B further comprises a structural unit represented by formula (10).
The polymer according to claim 1 or 2, wherein B further comprises a structural unit represented by formula (MA).
The polymer according to any one of claims 1 to 3, wherein ^Rp in the structural unit represented by formula (5) or (8) is at least one selected from the group represented by formula (1b), the group represented by formula (1c), and the group represented by formula (1d).
(In formula (1b),
k is 2 or 3,
R is a hydrogen atom or a methyl group, and multiple Rs may be the same or different.
^X1 is a single bond, an alkylene group having 1 to 6 carbon atoms, or a group represented by -L-M- (where L is -O- or -OCO-, and M is an alkylene group having 1 to 6 carbon atoms). Multiple ^X1 groups may be the same or different.
^X1 ' is a single bond, an alkylene group having 1 to 6 carbon atoms, or a group represented by -L'-M'- (where L' is an alkylene group having 1 to 6 carbon atoms, and M' is -O- or -COO-),
^X2 is a k+1 valent organic group with 1 to 12 carbon atoms.
(In formula (1c),
k, R, ^X1 , and ^X2 are equivalent to R, k, ^X1 , and ^X2 in equation (1b), respectively, and the multiple Rs may be the same or different from each other, and the multiple ^X1s may be the same or different from each other.
^X3 is a divalent organic group having 1 to 6 carbon atoms.
^X4 and ^X5 are each independently a single bond or a divalent organic group having 1 to 6 carbon atoms.
^X6 is a divalent organic group with 1 to 6 carbon atoms.
(In formula (1d),
n is an integer between 2 and 5.
R represents a hydrogen atom or a methyl group, and multiple Rs may be the same or different. The polymer according to any one of claims 1 to 4, wherein R ^s in the structural unit represented by formula (6) or (9) is a group represented by formula (2a).
(In formula (2a), X ¹⁰ is a divalent organic group, and R is a hydrogen atom or a methyl group.) A polymer according to any one of claims 1 to 5, wherein the weight-average molecular weight is 5,000 or more and 80,000 or less. A polymer solution comprising the polymer described in any one of claims 1 to 6. The polymer solution according to claim 7, further comprising at least one selected from a polyfunctional (meth)acrylic compound, a monofunctional (meth)acrylic compound, and a compound having a thiol group and an alkoxy group or its oligomer. A polymer solution according to claim 7 or 8, used for forming a color filter or a black matrix. A polymer solution according to claim 7 or 8,
A photosensitive resin composition comprising a photopolymerization initiator. A cured product of the photosensitive resin composition according to claim 10.