JP7631766B2 - Polymer, polymer solution, photosensitive resin composition and use thereof - Google Patents

Description

The present invention relates to a polymer, a polymer solution, a photosensitive resin composition, and uses thereof.

Liquid crystal display devices and solid-state imaging devices usually have color filters and black matrices. Photosensitive resin compositions are often used to form color filters and black matrices.

For example, claim 1 of Patent Document 1 describes a photosensitive resin composition that includes an alkali-soluble resin having, at least in a side chain, a group having an acidic group and two or more different polymerizable unsaturated groups, a polymerizable compound, and a photopolymerization initiator. In addition, an example of Patent Document 1 describes the synthesis of a methacrylic acid/allyl methacrylate/glycidyl adduct as an alkali-soluble resin, and the preparation of a photosensitive resin composition using this.

Patent Document 2 describes a resin composition that contains a resin containing epoxy groups and acid groups, a polybasic acid monoester of a hydroxyl group-containing polyfunctional (meth)acrylate, and a solvent, and is characterized in that the epoxy groups are present in an amount of 0.5 to 3.0 moles per mole of acid groups in the resin containing epoxy groups and acid groups.

Patent Document 3 discloses a method for producing a polymer, which includes a step of reacting a precursor polymer in which the maleic anhydride moiety has been ring-opened with a compound having an epoxy group. Glycidyl methacrylate is described as an example of the compound having an epoxy group.

International Publication No. 2012/147706 International Publication No. 2016/103844 International Publication No. 2017/154439

The photosensitive resin composition used to form color filters and black matrices uses a polymer that has the property of being hardened by a polymerization reaction caused by light. Color filters and black matrices are produced by patterning the photosensitive resin composition through exposure and development, and then hardening it.

In photosensitive resin compositions, "increasing sensitivity" seems to be a common issue, but with the increasing complexity and popularity of display devices and imaging devices, even higher levels of sensitivity are required. The higher the sensitivity of a photosensitive resin composition (the better the sensitivity), the shorter the time required for exposure, which can improve productivity.

On the other hand, when forming a color filter or a black matrix, the time required for developing the photosensitive resin composition is long, especially when the content of the pigment in the photosensitive resin composition is high, because the solubility of the pigment in the basic developer is low. Therefore, it is necessary to use a strong basic developer having a faster development speed than conventional basic developers. However, when the alkaline solubility of the polymer is high, the alkaline dissolution rate of the photosensitive resin composition containing the pigment and the photopolymerization initiator is too fast, or the difference in the dissolution rate between the pigment and the resin composition becomes large, so that the pattern after exposure and development may not have the shape as designed.
In Patent Documents 1 to 3, there is room for improvement in these characteristics.

The present inventors have found that when a strongly basic developer is used, in order to obtain a pattern after exposure and development in a designed shape, it is necessary to maintain and improve the sensitivity while adjusting the alkaline solubility of the polymer contained in the photosensitive resin composition. Furthermore, the present inventors have found that the problem can be solved by improving the polymer structure, and have completed the present invention.
That is, the present invention can be shown as follows.

（一般式（２）中、Ｒ ^１ 、Ｒ ^２ 、Ｒ ^３ およびＲ ^４ は、それぞれ独立して、水素原子または炭素数１～３０の有機基であり、ａ１は０、１または２である。）

（一般式（１－１）中、Ｚは１以上の（メタ）アクリロイル基を含む基である。Ｑは水素原子または置換または未置換の炭素数１～６のアルキル基である。Ｘは酸素原子、置換または未置換の炭素数１～４のアルキレン基を表し、Ｑの前記アルキル基とＸの前記アルキレン基の何れかの炭素原子とが結合して環を形成してもよい。一般式（１－２）中、Ｒ^Ｄは、多官能（メタ）アクリロイル基を含む基である。）
本発明によれば、
前記ポリマーを含む、ポリマー溶液を提供することができる。
本発明によれば、
前記ポリマー溶液と、
多官能（メタ）アクリレートモノマーと、
光重合性開始剤と、
を含む、感光性樹脂組成物を提供することができる。
本発明によれば、
前記感光性樹脂組成物の硬化物を提供することができる。
本発明によれば、
前記硬化物からなるフィルムを提供することができる。 According to the present invention,
It is possible to provide a polymer including a structural unit represented by the following general formula (2), a structural unit represented by the following general formula (1-1), and a structural unit represented by the following general formula (1-2).

(In general formula (2), R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom or an organic group having 1 to 30 carbon atoms, and a1 is 0, 1 or 2.)

(In general formula (1-1), 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 is an oxygen atom or a substituted or unsubstituted alkylene group having 1 to 4 carbon atoms, and the alkyl group of Q and any carbon atom of the alkylene group of X may be bonded to form a ring. In general formula (1-2), R ^D is a group containing a polyfunctional (meth)acryloyl group.)
According to the present invention,
A polymer solution can be provided that includes the polymer.
According to the present invention,
The polymer solution;
A polyfunctional (meth)acrylate monomer;
A photopolymerization initiator;
It is possible to provide a photosensitive resin composition comprising:
According to the present invention,
A cured product of the photosensitive resin composition can be provided.
According to the present invention,
It is possible to provide a film made of the cured product.

According to the present invention, a polymer having excellent sensitivity and excellent alkali solubility can be provided, and can be suitably used as a polymer for forming a color filter or a black matrix. In other words, the polymer of the present invention has an excellent balance of these properties.

FIG. 1 is a diagram (cross-sectional view) illustrating a schematic example of a structure of a liquid crystal display device and/or a solid-state imaging device. 1 is a ¹ H-NMR chart of polymer P3 obtained in Example 1. This is an enlarged view of the peak near 6.0 ppm in ^{the 1} H-NMR chart of FIG.

The following describes an embodiment of the present invention with reference to the drawings. In all drawings, similar components are given similar reference numerals and descriptions are omitted as appropriate. In addition, all drawings are for explanatory purposes only. The shapes and dimensional ratios of each component in the drawings do not necessarily correspond to actual objects. In this specification, the notation "a-b" in the explanation of a numerical range means a or more and b or less, unless otherwise specified. For example, "5-90%" means "5% or more and 90% or less."

In this specification, when a group (atomic group) is represented without specifying whether it is substituted or unsubstituted, it includes both groups that have no substituents and groups that have a substituent. For example, "alkyl group" includes not only alkyl groups that have no substituents (unsubstituted alkyl groups), but also alkyl groups that have a substituent (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 represents a concept that includes an acryloyl group represented by -C(=O)-CH= _CH2 and a methacryloyl group represented by -C(=O)-C( _CH3 )= _CH2 .

[Polymer P]
The polymer P of the present embodiment contains a structural unit represented by the following general formula (1-1) and a structural unit represented by the following general formula (1-2). The polymer P containing these structural units is excellent in sensitivity and alkali solubility. In other words, it has an excellent balance of these properties, and is particularly excellent in sensitivity.

In general formula (1-1), 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 is an oxygen atom or a substituted or unsubstituted alkylene group having 1 to 4 carbon atoms, and the alkyl group of Q and any carbon atom of the alkylene group of X may be bonded to form a ring.
In the general formula (1-2), R 1 ^D is a group containing a polyfunctional (meth)acryloyl group.

The polymer P of this embodiment contains a structural unit represented by general formula (1-1) and a structural unit represented by general formula (1-2), and therefore has excellent sensitivity and alkaline solubility, and can be suitably used as a polymer for forming a color filter or a black matrix. In particular, the polymer P of this embodiment has adjusted alkaline solubility and excellent sensitivity, so that when a strong basic developer such as a tetramethylammonium hydroxide (TMAH) solution is used, the pattern after exposure and development can be formed into the designed shape.

In general formula (1-1), Z is not particularly limited as long as it is a group containing one or more (meth)acryloyl groups, but is more preferably a group containing 1 to 4 (meth)acryloyl groups, and even more preferably a group containing 1 to 3 (meth)acryloyl groups. By optimizing the number of (meth)acryloyl groups contained in Z, the composition has excellent sensitivity and excellent alkali solubility (developability), in other words, a good balance between these properties.

From the viewpoint of these properties, Z is preferably a group containing one (meth)acryloyl group, and more preferably a group represented by the following general formula (1a):

In general formula (1a), R is a hydrogen atom or a methyl group.

In general formula (1-1), Q is a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms.
Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. Examples of the substituent of the substituted alkyl group having 1 to 6 carbon atoms include a halogen atom, a hydroxyl group, a carboxyl group, an amino group, a cyano group, and a mercapto group.

In the general formula (1-1), X is an oxygen atom or a substituted or unsubstituted alkylene group having 1 to 4 carbon atoms.
Examples of the alkylene group include a methylene group, an ethylene group, a propylene group, and a butylene group. Examples of the substituent of the substituted alkylene group having 1 to 4 carbon atoms include a halogen atom, a hydroxyl group, a carboxyl group, an amino group, a cyano group, and a mercapto group.

In general formula (1-1), the alkyl group of Q and any carbon atom of the alkylene group of X may be bonded to form a ring. Examples of the ring structure include a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a decalin ring, a benzene ring, and a naphthalene ring.

In the general formula (1-2), R ^D is not particularly limited as long as it is a group containing two or more (meth)acryloyl groups, but is more preferably a group containing 2 to 6 (meth)acryloyl groups, and even more preferably a group containing 3 to 5 (meth)acryloyl groups. By optimizing the number of (meth)acryloyl groups contained in R ^D , it is possible to further increase sensitivity. In addition, it becomes easier to achieve a high degree of compatibility between sensitivity and developability. Furthermore, it becomes easier to further increase heat resistance.

From the viewpoint of further improving sensitivity and of preventing steric hindrance, it is preferred that R 3 ^D contains two or more acryloyl groups (groups represented by -C(=O)-CH=CH ₂ ).

R 3 ^D is preferably a group represented by the following general formula (1b), (1c) or (1d): By using such a group, the above-mentioned various effects tend to be easily obtained.

In general formula (1b),
k is 2 or 3;
R is a hydrogen atom or a methyl group, and multiple R may be the same or different.
X ¹ is a single bond, an alkylene group having 1 to 6 carbon atoms, or a group represented by -Z-X- (Z is -O- or -OCO-, and X is an alkylene group having 1 to 6 carbon atoms), and a plurality of X ^1s may be the same or different;
X ¹ ' is a single bond, an alkylene group having 1 to 6 carbon atoms or a group represented by -X'-Z'- (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 having 1 to 12 carbon atoms.
R is preferably a hydrogen atom in view of further improving sensitivity (ease of polymerization) and the like.
Although k may be 2 or 3, it is preferably 3 from the viewpoints of availability of raw materials and further improvement of sensitivity.

When X ¹ is an alkylene group having 1 to 6 carbon atoms, the alkylene group may be linear or branched.
When X ¹ is an alkylene group having 1 to 6 carbon atoms, X ¹ is preferably a linear alkylene group, more preferably a linear alkylene group having 1 to 3 carbon atoms, and further preferably -CH ₂ - (methylene group).

When ^X1 is a group represented by -ZX- (Z is -O- or -OCO-, and X is an alkylene group having 1 to 6 carbon atoms), the alkylene group having 1 to 6 carbon atoms of X may be linear or branched.

The alkylene group having 1 to 6 carbon atoms for X 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 X ¹ ' is an alkylene group having 1 to 6 carbon atoms, specific embodiments thereof are the same as those of X ¹ .
When X ¹ ' is a group represented by -X'-Z'-, specific embodiments of X' are the same as those of X above.

The k+1 valent organic group having 1 to 12 carbon atoms for ^X2 may be any group obtained by removing k+1 hydrogen atoms from any organic compound. The "any organic compound" here is, for example, an organic compound having a molecular weight of 300 or less, preferably 200 or less, more preferably 100 or less.

^X2 is, for example, a group in which k+1 hydrogen atoms have been removed from a linear or branched hydrocarbon having 1 to 12 carbon atoms (preferably 1 to 6 carbon atoms). More preferably, it is a group in which k+1 hydrogen atoms have been removed from a linear hydrocarbon having 1 to 3 carbon atoms. The hydrocarbon here may contain an oxygen atom (for example, an ether bond or a hydroxyl group). In addition, the hydrocarbon is preferably a saturated hydrocarbon.

In another embodiment, ^X2 may be a group containing a cyclic structure. Examples of the group containing a cyclic structure include a group containing an alicyclic structure and a group containing a heterocyclic structure (for example, an isocyanuric acid structure).

In general formula (1c),
k, R, ^X1 , and ^X2 are the same as R, k, ^X1 , and ^X2 in the above general formula (1b), respectively, and a plurality of R may be the same or different from each other, and a plurality of ^X1 may be the same or different from each other;
^X3 is a divalent organic group having 1 to 6 carbon atoms;
^X4 and ^X5 each independently represent 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.
Specific and preferred aspects of R, k, ^X1 and ^X2 are the same as those explained in relation to formula (1b).

Examples of the divalent organic group having 1 to ⁶ carbon atoms for ^X3 and X6 include a group in which two hydrogen atoms have been removed from a linear or branched hydrocarbon having 1 to 6 carbon atoms. The hydrocarbon may contain an oxygen atom (e.g., an ether bond or a hydroxyl group). The hydrocarbon is preferably a saturated hydrocarbon.

The divalent organic group having 1 to 6 carbon atoms for ^X4 and ^X5 may be a linear or branched alkylene group. The linear or branched alkylene group preferably has 1 to 3 carbon atoms.

In general formula (1d), n is an integer from 2 to 5, preferably 2 or 3.

In the total structural units of the polymer P of this embodiment, the proportion of the structural units represented by general formula (1-1) is preferably 0.5 to 20 mol %, more preferably 1 to 15 mol %. The proportion of the structural units represented by general formula (1-2) is preferably 1 to 30 mol %, more preferably 2 to 20 mol %.

The polymer P of this embodiment may contain a structural unit represented by the following general formula (1), which is composed of a structural unit represented by general formula (1-1) and a structural unit represented by general formula (1-2). The polymer P containing the structural unit represented by the following general formula (1) is excellent in sensitivity and alkali solubility. In other words, it has an excellent balance of these properties, and is particularly excellent in sensitivity.

In formula (1), Q, X and Z are defined as same as in formula (1-1), and R ^D is defined as same as in formula (1-2).
The proportion of the structural unit represented by formula (1) in all structural units of the polymer P of this embodiment is preferably 0.25 to 17 mol %, more preferably 0.5 to 12 mol %.
The polymer P of the present embodiment may also contain a structural unit represented by the general formula (3), a structural unit represented by the general formula (5), or a structural unit represented by the general formula (6), which will be described later, as a structural unit containing the structural unit represented by the general formula (1-1). These structural units will be described later.
Furthermore, the polymer P of the present embodiment may also contain a structural unit represented by the general formula (8) described below as a structural unit containing the structural unit represented by the general formula (1-2). This structural unit will be described later.

The polymer P of this embodiment may further include a structural unit represented by the following general formula (2):

In formula (2), R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom or an organic group having 1 to 30 carbon atoms; a1 is 0, 1 or 2.

The structural unit represented by general formula (2) is chemically robust. Therefore, polymer P containing this structural unit undergoes little weight loss when subjected to heat treatment and is stable. Therefore, 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 imaging devices that require heat resistance.

Examples of the organic group having 1 to 30 carbon atoms that can constitute R ¹ to R ⁴ include substituted or unsubstituted, linear or branched alkyl groups having 1 to 30 carbon atoms, more specifically, alkyl groups, alkenyl groups, alkynyl groups, alkylidene groups, aryl groups, aralkyl groups, alkaryl groups, cycloalkyl groups, alkoxy groups, heterocyclic groups, and carboxyl groups.

Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a neopentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group.
Examples of the alkenyl group include an allyl group, a pentenyl group, and a vinyl group.
The alkynyl group includes, for example, an ethynyl group.
Examples of the alkylidene group include a methylidene group and an ethylidene group.

Examples of the aryl group include a tolyl group, a xylyl group, a phenyl group, a naphthyl group, and an anthracenyl group.
Examples of the aralkyl group include a benzyl group and a phenethyl group.
Examples of the alkaryl group include a tolyl group and a xylyl group.
Examples of the cycloalkyl group include an adamantyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group.

Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, an isobutoxy group, a tert-butoxy group, an n-pentyloxy group, a neopentyloxy group, and an n-hexyloxy group.
Examples of the heterocyclic group include an epoxy group and an oxetanyl group.

In the structural unit represented by formula (2), R ¹ , R ² , R ³ and R ⁴ are preferably hydrogen or an alkyl group, and more preferably hydrogen.

The hydrogen atoms in the organic groups having 1 to 30 carbon atoms of R ¹ , R ² , R ³ and R ⁴ may be substituted with any atomic group. For example, they may be substituted with fluorine atoms, hydroxyl groups, carboxyl groups, etc. More specifically, a fluorinated alkyl group may be selected as the organic group having 1 to 30 carbon atoms of R ¹ , R ² , R ³ and R ⁴ .
In the structural unit represented by formula (2), a1 is preferably 0 or 1, and more preferably 0.

The proportion of the structural units represented by general formula (2) in all 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 %.

The polymer P of the present embodiment may further include a structural unit represented by the following general formula (3-1).

In general formula (3-1), R 1 ^S is a group containing only one (meth)acryloyl group. In particular, in the design of a typical photosensitive resin composition, when the curability is increased in order to increase the sensitivity, the curing tends to proceed too much, resulting in poor developability, whereas when the developability is improved, the curing tends to be insufficient. Therefore, it is preferable that the polymer P further contains a structural unit represented by general formula (3-1), thereby achieving a good balance between the sensitivity and the developability.

R 1 ^S is, for example, a group represented by the following general formula (3a).

In formula (3a), ^X10 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 1-30, more preferably 1-20, and even more preferably 1-10.
In formula (3a), ^X10 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 1-30, more preferably 1-20, and even more preferably 1-10.

The divalent organic group of X ¹⁰ is preferably, for example, an alkylene group. A portion of -CH ₂ - in this alkylene group may be an ether group (-O-). The alkylene group may be linear or branched, but is more preferably linear.

The divalent organic group of X ¹⁰ is more preferably a linear alkylene group having a total carbon number of 3 to 6. By appropriately selecting the number of carbon atoms of X ¹⁰ (the chain length of X ¹⁰ ), the structural unit represented by general formula (3-1) becomes more likely to participate in the crosslinking reaction, and the sensitivity can be increased.

The divalent organic group (e.g., an alkylene group) of X ¹⁰ may be substituted with any substituent. Examples of the substituent include an alkyl group, an aryl group, an alkoxy group, and an aryloxy group.

The divalent organic group of ^X10 may be any group other than an alkylene group, for example, a divalent group formed by linking one or more groups selected from an alkylene group, a cycloalkylene group, an arylene group, an ether group, a carbonyl group, a carboxy group, and the like.

In the present embodiment, the proportion of the structural units represented by general formula (3-1) in all structural units of polymer P is preferably 5 to 40 mol %, more preferably 10 to 30 mol %.

The polymer P of this embodiment can contain a structural unit represented by the following general formula (3), which is composed of a structural unit represented by general formula (1-1) and a structural unit represented by general formula (3-1).

In formula (3), Z, Q and X are defined as in formula (1-1), and R 1 and R ² are defined as in formula (3-1).

When the polymer P contains a structural unit represented by the general formula (3), the proportion of the structural unit represented by the general formula (3) in all structural units of the polymer P is preferably 3 to 35 mol %, more preferably 7 to 25 mol %.
The polymer P of the present embodiment may also contain a structural unit represented by the general formula (8) described below as a structural unit containing the structural unit represented by the general formula (3-1). This structural unit will be described later.

The polymer P of this embodiment may further include a structural unit represented by the following general formula (4):

By containing the structural unit represented by general formula (4) in addition to the structural unit represented by general formula (1-1) and the structural unit represented by general formula (1-2), the polymer P can adjust its alkali solubility. As a result, the photosensitive resin composition containing the polymer P has an excellent balance of sensitivity and developability even when subjected to photolithography processing using a strongly basic developer.

When polymer P contains a structural unit represented by general formula (4), the proportion of the structural unit represented by general formula (4) in the total structural units of polymer P is preferably 1 to 15 mol %, more preferably 2 to 10 mol %.

The polymer P of this embodiment may further contain a structural unit represented by the following general formula (5), which contains a structural unit represented by general formula (1-1). By containing this structural unit, it is possible to achieve a better balance between both sensitivity and developability.

In formula (5), Z, X and Q are the same as those in formula (1-1).
When the polymer P contains a structural unit represented by the general formula (5), the proportion of the structural unit represented by the general formula (5) in all structural units of the polymer P is preferably 1 to 12 mol %, more preferably 1 to 9 mol %.

From the viewpoint of the effects of the present invention, the polymer P of this embodiment may further contain a structural unit represented by the following general formula (6) which is composed of two structural units represented by general formula (1-1). By containing this structural unit, the sensitivity can be further improved.

In general formula (6), Z, X, and Q have the same meanings as in general formula (1-1). Multiple Zs, multiple Qs, and multiple Xs may be the same or different.

When polymer P contains a structural unit represented by general formula (6), the proportion of the structural unit represented by general formula (6) in the total structural units of polymer P is preferably 1 to 10 mol %, more preferably 1 to 8 mol %.

From the viewpoint of the effects of the present invention, the polymer P of this embodiment may further contain a structural unit represented by the following general formula (7) and/or a structural unit represented by the following general formula (8).

In formula (7), R 3 ^D has the same meaning as in formula (1-2).
When the polymer P contains a structural unit represented by the general formula (7), the proportion of the structural unit represented by the general formula (7) in all structural units of the polymer P is preferably 0.5 to 25 mol %, more preferably 1 to 18 mol %.

From the viewpoint of the effects of the present invention, the polymer P of this embodiment may further contain a structural unit represented by the following general formula (8).

In formula (8), Q, X and Z are the same as defined in formula (3-1).
When the polymer P contains a structural unit represented by general formula (8), the proportion of the structural unit represented by general formula (8) in all structural units of the polymer P is preferably 3 to 35 mol %, more preferably 5 to 25 mol %.

In this embodiment, the polymer P may contain a structural unit represented by the general formula (MA) in addition to the above structural units. The structural unit represented by the general formula (MA) is ring-opened by an alkaline developer to generate two carboxyl groups. Therefore, the polymer P containing this structural unit has excellent developability. When the polymer P contains a structural unit represented by the general formula (MA), the structural unit represented by the general formula (MA) is preferably 1 to 30 mol %, more preferably 2 to 25 mol %, of all the structural units of the polymer P.

The content (ratio) of each structural unit contained in polymer P can be estimated/calculated from the amount (molar amount) of raw materials used in synthesizing polymer P, the amount of raw materials remaining after synthesis, the presence of peaks in various spectra (e.g., IR spectrum, ^1H -NMR spectrum, ^13C -NMR spectrum), the peak area, etc.

The weight average molecular weight Mw of the polymer P is, for example, 2,000 to 200,000, preferably 3,000 to 150,000, more preferably 5,000 to 100,000, and even more preferably 8,000 to 80,000. By appropriately adjusting the weight average molecular weight, it is possible to adjust the sensitivity and solubility in an alkaline developer.

The dispersity of polymer P (weight average molecular weight Mw/number average molecular weight Mn) is preferably 1.0 to 8.0, more preferably 1.5 to 7.0, and even more preferably 2.0 to 6.0. By appropriately adjusting the dispersity, the physical properties of polymer P can be made homogenous, which is preferable. These values can be determined by gel permeation chromatography (GPC) measurements 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 the inclusion of structural units mainly represented by general formula (2). This is preferable in that the pattern formed on the substrate can be stable when manufacturing liquid crystal display devices and solid-state imaging devices. The glass transition temperature can be determined, for example, by differential thermal analysis (DTA).

The acid value of the polymer P is 70 mgKOH/g or more and 150 mgKOH/g or less, preferably 80 mgKOH/g or more and 140 mgKOH/g or less.
When the acid value is within this range, the sensitivity and the alkali solubility are excellent, in other words, these properties are well balanced.

The acid value can be measured by the following method.
Specifically, ^the amount of carboxyl groups is determined from the integral value of the H peak (near 12.4 ppm) of the carboxyl groups (--COOH) of polymer P, based on the integral value of the 4H peak (near 8.1 ppm) of the phenyl group of dimethyl terephthalate, the internal standard for 1H-NMR measurement. The acid value (mg KOH/g) can then be calculated from the amount.

(Production of Polymer P)
The polymer P of this embodiment can be produced (synthesized) by any method. The production method of the polymer P will be described with reference to a first embodiment and a second embodiment.
In the first and second embodiments, the polymer precursor P′ is shown as including a structural unit represented by general formula (8), but the structural unit is optional, and the polymer P of this embodiment may include a structural unit represented by general formula (8) and a structural unit represented by general formula (3).

(First embodiment)
The method for producing the polymer P of this embodiment is as follows:
(I) a first step of preparing a polymer precursor (hereinafter referred to as "polymer precursor P'") including a structural unit represented by the following general formula (2), a structural unit represented by the following general formula (7), a structural unit represented by the following general formula (8), and a structural unit represented by the following general formula (MA);

(II) a second step of reacting the polymer precursor P′ obtained in the first step with an epoxy group-containing (meth)acrylic compound in the presence of a catalyst to prepare a polymer P including a structural unit represented by the following general formula (1), a structural unit represented by the following general formula (2), a structural unit represented by the following general formula (3), a structural unit represented by the following general formula (7), a structural unit represented by the following general formula (8), and optionally a structural unit represented by the following general formula (MA);
Includes.

Hereinafter, the method for producing (synthesizing) the polymer P of this embodiment through these steps will be described.
The first step (I) of preparing the polymer precursor P′ comprises
(I-i) preparing a raw material polymer including a structural unit represented by the following general formula (2) and a structural unit represented by the following general formula (MA);

(I-ii) A step of reacting the raw polymer obtained in step (I-i) with a compound having a hydroxyl group and two or more (meth)acryloyl groups (hereinafter referred to as a "polyfunctional (meth)acrylic compound") in the presence of a basic catalyst to prepare a first polymer precursor containing a structural unit represented by the following general formula (2), a structural unit represented by the following general formula (7), and a structural unit represented by the following general formula (MA);

(I-iii) It is preferable to include a step of reacting the first polymer precursor obtained in step (I-ii) with 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 second polymer precursor containing a structural unit represented by the following general formula (2), a structural unit represented by the following general formula (7), a structural unit represented by the following general formula (8), and a structural unit represented by the following general formula (MA). Here, the second polymer precursor obtained in step (I-iiii) corresponds to the polymer precursor P' described in the above step (I).

(Step (I-i))
In the step (I-i), the step of preparing a raw material polymer containing a structural unit represented by general formula (2) and a structural unit represented by general formula (MA) can be produced by polymerizing (addition polymerization) a monomer represented by general formula (NBm) and maleic anhydride. The definitions of R ¹ , R ² , R ³ , R ⁴ and a1 in general formula (NBm) are the same as those in general formula (2). The same also applies to preferred aspects.

Examples of monomers represented by the general formula (NBm) include norbornene, norbornadiene, bicyclo[2.2.1]-hept-2-ene (common name: 2-norbornene), 5-methyl-2-norbornene, 5-ethyl-2-norbornene, 5-butyl-2-norbornene, 5-hexyl-2-norbornene, 5-decyl-2-norbornene, 5-allyl-2-norbornene, 5-(2-propenyl)-2-norbornene, 5-(1-methyl-4-pentenyl)-2-norbornene, 5-ethynyl-2-norbornene, 5-benzyl-2-norbornene, 5-phenethyl-2-norbornene, 2-acetyl-5-norbornene, methyl 5-norbornene-2-carboxylate, and 5-norbornene-2,3-dicarboxylic anhydride. During polymerization, the monomer represented by general formula (NBm) may be used alone or in combination of two or more.

The polymerization method is not limited, but radical polymerization using a radical polymerization initiator is preferred. Examples of the polymerization initiator that can be used include azo compounds and organic peroxides.

Specific examples of azo compounds include azobisisobutyronitrile (AIBN), dimethyl 2,2'-azobis(2-methylpropionate), and 1,1'-azobis(cyclohexanecarbonitrile) (ABCN).

Examples of organic peroxides include hydrogen peroxide, di-tert-butyl peroxide (DTBP), benzoyl peroxide (BPO), and methyl ethyl ketone peroxide (MEKP).
The polymerization initiator may be used alone or in combination of two or more kinds.

As the polymerization solvent, for example, an organic solvent such as diethyl ether, tetrahydrofuran, toluene, or methyl ethyl ketone can be used. The polymerization solvent may be a single solvent or a mixed solvent.

The synthesis of the raw polymer is carried out by dissolving the monomer represented by the general formula (NBm), maleic anhydride, and a polymerization initiator in a solvent and charging the resulting solution into a reaction vessel, and then heating the mixture 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.

The molar ratio of the monomer represented by formula (NBm) to maleic anhydride when charged into a reaction vessel is preferably 0.5:1 to 1:0.5. From the viewpoint of controlling the molecular structure, the molar ratio is preferably 1:1.
Through such a process, a "raw polymer" can be obtained.

The raw polymer may be any of random copolymers, alternating copolymers, block copolymers, and periodic copolymers. Typically, it is a random copolymer or an alternating copolymer. Maleic anhydride is generally known as a monomer with strong alternating copolymerizability.
After synthesis of the raw polymer, a step of removing low molecular weight components such as unreacted monomers, oligomers, and residual polymerization initiators may be carried out.

Specifically, the organic phase containing the synthesized raw 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 monomer. The precipitate is filtered and dried to increase the purity of the raw polymer.

(Step (I-ii))
The raw material polymer obtained in step (I-i) is reacted with a polyfunctional (meth)acrylic compound in the presence of a basic catalyst, whereby a part of the structural units represented by general formula (MA) contained in the raw material polymer is ring-opened to form structural units represented by general formula (7), thereby obtaining a first polymer precursor containing structural units represented by general formula (2), structural units represented by general formula (MA), and structural units represented by general formula (7).

More specifically, first, a solution is prepared by dissolving the raw polymer in an appropriate organic solvent. As the organic solvent, a single solvent or a mixed solvent such as methyl ethyl ketone (MEK), propylene glycol monomethyl ether acetate (PGMEA), dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), tetrahydrofuran (THF), etc. can be used, but it is not limited to these, and various organic solvents used in the synthesis of organic compounds and polymers can be used.
Next, a polyfunctional (meth)acrylic compound is added to the above solution, and a basic catalyst is further added, and the solution is mixed appropriately to obtain a homogeneous solution.

Examples of the polyfunctional (meth)acrylic compound include a compound represented by general formula (1b-m), a compound represented by general formula (1c-m), or a compound represented by general formula (1d-m). The definitions and specific aspects of k, R, X ¹ , X ¹ ', and X ² in general formula (1b-m) are the same as those in the above-mentioned general formula (1b). The definitions and specific aspects of k, R, X ¹ , X ² , X ³ , X ⁴ , X ⁵ , and X ⁶ in general formula (1c-m) are the same as those in the above-mentioned general formula (1c). The definition of n in general formula (1d-m) is the same as that in the above-mentioned general formula (1d).

Specific examples of polyfunctional (meth)acrylic compounds represented by general formula (1b-m) include, but are not limited to, the following compounds:

Specific examples of polyfunctional (meth)acrylic compounds represented by general formula (1c-m) include, but are not limited to, the following compounds:

As the basic catalyst, amine compounds and nitrogen-containing heterocyclic compounds known in the field of organic synthesis can be appropriately used. For example, amine compounds or nitrogen-containing heterocyclic compounds such as triethylamine, pyridine, and dimethylaminopyridine can be used as catalysts. The amount of the basic catalyst used can be, for example, about 10 to 60 parts by mass per 100 parts by mass of the raw polymer.

The solution is heated, preferably at 60 to 80°C, for about 3 to 9 hours, to open some of the structural units of general formula (MA) contained in the raw polymer and form structural units of general formula (7), producing a first polymer precursor containing structural units represented by general formula (2), structural units represented by general formula (MA), and structural units represented by general formula (7).

(Step (I-iii))
Next, the first polymer precursor obtained in step (I-ii) is reacted with a monofunctional (meth)acrylic compound in the presence of a basic catalyst, whereby a part of the structural units represented by general formula (MA) contained in the first polymer precursor is ring-opened to form structural units represented by general formula (8). As a result, a second polymer precursor containing structural units represented by general formula (2), structural units represented by general formula (MA), structural units represented by general formula (7), and structural units represented by general formula (8), i.e., polymer precursor P', is obtained.

It is preferable to carry out step (I-iii) by adding a monofunctional (meth)acrylic compound to the reaction system containing the first polymer precursor obtained in step (I-ii). Note that, from the viewpoint of steric hindrance of the reaction, monofunctional (meth)acrylic compounds tend to react more easily with the raw material polymer than polyfunctional (meth)acrylic compounds. Therefore, it is preferable to carry out step (I-ii) of reacting a monofunctional (meth)acrylic compound and step (I-iii) of reacting a monofunctional (meth)acrylic compound sequentially in this order, rather than simultaneously.

The reaction between the monofunctional (meth)acrylic compound and the first polymer precursor proceeds in the presence of a basic catalyst. The basic catalyst may be the catalyst remaining in the reaction system obtained in step (I-ii) as it is. Therefore, it is preferable to carry out step (I-iii) in situ by adding the monofunctional (meth)acrylic compound to the reaction mixture containing the first polymer precursor obtained in step (I-ii) without isolating and purifying the first polymer precursor from the reaction mixture containing the first polymer precursor obtained in step (I-ii) or neutralizing the basic catalyst contained in the mixture.

Specifically, a monofunctional (meth)acrylic compound is added to a reaction mixture containing a first polymer precursor, and the resulting reaction solution is heated, preferably at 60 to 80°C, for about 1 to 9 hours, whereby some of the structural units represented by general formula (MA) contained in the first polymer precursor are ring-opened to form structural units represented by general formula (8), thereby producing polymer precursor P'.

The monofunctional (meth)acrylic compound used in the step (I-iii) may, for example, be a compound represented by the following general formula (3a-m): In the general formula (3a-m), the definitions of ^X10 and R are the same as those in the general formula (3a).

Specific examples of compounds represented by general formula (3a-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.

(Step II)
The polymer precursor P' obtained in the first step (I) is reacted with an epoxy group-containing (meth)acrylic compound in the presence of a catalyst, and a structural unit represented by general formula (1) and a structural unit represented by general formula (3) are formed by a reaction between a carboxyl group of the polymer precursor P' and an epoxy group of the epoxy group-containing (meth)acrylic compound, thereby preparing a polymer P containing a structural unit represented by general formula (1), a structural unit represented by the above general formula (2), a structural unit represented by the above general formula (3), a structural unit represented by the above general formula (7), a structural unit represented by the above general formula (8), and optionally a structural unit represented by the above general formula (MA).

It is preferable to carry out step (II) by adding an epoxy group-containing (meth)acrylic compound to the reaction system containing the polymer precursor P' obtained in step (I-iii).

The reaction between the polymer precursor P' and the epoxy group-containing (meth)acrylic compound proceeds in the presence of a basic catalyst. The basic catalyst may be the catalyst remaining in the reaction system obtained in step (I-iii) as is. Therefore, it is preferable to carry out step (II) in situ by adding the epoxy group-containing (meth)acrylic compound to the reaction mixture containing the polymer precursor P' obtained in step (I-iii) without isolating and purifying the polymer precursor P' from the reaction mixture containing the polymer precursor P' obtained in step (I-iii) 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 polymer precursor P' is heated, preferably at 60 to 80°C, for about 1 to 9 hours. The carboxyl groups of polymer precursor P' react with the epoxy groups of the epoxy group-containing (meth)acrylic compound to form structural units represented by general formula (1) and structural units represented by general formula (3), producing polymer P.

Examples of epoxy group-containing (meth)acrylic compounds include glycidyl methacrylate (GMA), 4-hydroxybutyl acrylate glycidyl ether (4HBAGE), 3,4-epoxycyclohexylmethyl acrylate, 3,4-epoxycyclohexylmethyl methacrylate, glycidyl acrylate, etc., and one or more selected from 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 group in the polymer precursor P'.

After step (II), it is preferable to further carry out the following steps as appropriate to remove unnecessary components other than the desired polymer P.

First, the reaction solution diluted with the 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 is left to stand for 30 minutes or more to separate into an organic phase and an 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 obtained organic solution of polymer P to reprecipitate polymer P. The polymer powder obtained by the reprecipitation is further washed several times (for example, twice) with toluene.
Furthermore, in order to remove the acid or basic catalyst, the obtained polymer powder is washed with ion-exchanged water several times (for example, three times).
The polymer powder washed with ion-exchanged water is dried, for example, at 30 to 60° C. for 16 hours or more, to obtain a high-purity polymer P of this embodiment.

Second Embodiment
The method for producing the polymer P of this embodiment is as follows:
(a) a first step of preparing a polymer precursor (hereinafter referred to as "polymer precursor P'") including a structural unit represented by the following general formula (2), a structural unit represented by the following general formula (7), a structural unit represented by the following general formula (8), and a structural unit represented by the following general formula (MA);

(b) A second step of treating the polymer precursor P' obtained in the first step with water in the presence of a catalyst to prepare a polymer precursor (hereinafter referred to as "polymer precursor P") that contains a structural unit represented by the following general formula (2), a structural unit represented by the following general formula (4), a structural unit represented by the following general formula (7), and a structural unit represented by the following general formula (8), and optionally a structural unit represented by the following general formula (MA);

(c) a third step of reacting the polymer precursor P" obtained in the second step with an epoxy group-containing (meth)acrylic compound in the presence of a catalyst to prepare a polymer containing a structural unit represented by the following general formula (1), a structural unit represented by the following general formula (2), a structural unit represented by the following general formula (3), a structural unit represented by the following general formula (4), a structural unit represented by the following general formula (5), a structural unit represented by the following general formula (6), a structural unit represented by the following general formula (7), a structural unit represented by the following general formula (8), and optionally a structural unit represented by the following general formula (MA);
Includes.

The method for producing (synthesizing) the polymer of this embodiment using these steps will be described below. Note that the first step (a) of preparing the polymer precursor is similar to the first step (I) of this embodiment, so a description thereof will be omitted.

(Step (b))
The polymer precursor P' obtained in step (a) is treated with water in the presence of a catalyst, whereby the structural unit represented by general formula (MA) contained in the polymer precursor P' undergoes ring-opening to form the structural unit represented by general formula (4), thereby producing a polymer precursor P" containing the structural unit represented by general formula (2), the structural unit represented by general formula (4), the structural unit represented by general formula (7), and the structural unit represented by general formula (8). When a part of the structural unit represented by general formula (MA) undergoes ring-opening and a part of the structural unit of general formula (MA) remains without being ring-opened, the polymer contains the structural unit represented by general formula (MA) in addition to the structural units of general formula (2), general formula (4), general formula (7), and general formula (8).

Step (b) is preferably carried out by adding water to the reaction system containing the polymer precursor P' obtained in the above step (I-iii). A basic catalyst can be used as the catalyst used in step (b), and the same catalyst as the basic catalyst used in the above step (I-ii) or step (I-iii) can be used. Specific examples of basic catalysts include amine compounds such as triethylamine, pyridine, and dimethylaminopyridine, or nitrogen-containing heterocyclic compounds.

In step (b), water is added to the reaction system containing the polymer precursor P' obtained in the above-mentioned step (I-iii), and the resulting reaction solution is heated, preferably at 60 to 80°C, for about 0.25 to 6 hours, to open the structural unit of general formula (MA) contained in the polymer precursor P' and generate the structural unit represented by general formula (4). This reaction proceeds in the presence of a basic catalyst. The basic catalyst remaining in the reaction system obtained in step (I-iii) can be used as it is. Therefore, step (b) is preferably carried out in situ by adding water to the reaction mixture containing the polymer precursor P' obtained in step (I-iii) without isolating and purifying the polymer precursor P' from the reaction mixture containing the polymer precursor P' obtained in step (I-iii) or neutralizing the basic catalyst contained in the mixture.

In the third step (c), the polymer precursor P″ obtained in the second step (b) is reacted with an epoxy group-containing (meth)acrylic compound in the presence of a catalyst to prepare a polymer P. Note that the reaction conditions in the third step (c) are the same as those in the second step (ii) of the first embodiment, and therefore the explanation thereof will be omitted.
After the third step (c), in order to remove unnecessary components other than the desired polymer P, it is preferable to appropriately carry out a washing step or the like as in the first embodiment.

[Polymer solution]
The polymer solution of this embodiment contains the polymer P described above.
Furthermore, the polymer P may contain at least one compound selected from a polyfunctional (meth)acrylic compound and a monofunctional (meth)acrylic compound, as long as the effect of the present invention is not adversely affected.

[Polyfunctional (meth)acrylic compound]
As the polyfunctional (meth)acrylate compound, which is a compound having two or more (meth)acryloyl groups, any conventionally known compound can be used as long as it can exert the effects of the present invention.
Examples of the polyfunctional (meth)acrylic compound include, but are not limited to, a compound represented by the following general formula (1b-p), a compound represented by the general formula (1c-p), and a compound represented by the general formula (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) above. 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) above.

In general formulae (1b-p), (1c-p) and (1d-p), Y represents a hydrogen atom, a (meth)acryloyl group, or a combination thereof.
The compounds in which Y is a hydrogen atom in general formula (1b-p), general formula (1c-p), and general formula (1d-p) may be unreacted monomers (i.e., compounds represented by general formula (1b-p), general formula (1c-p), and general formula (1d-p)), or may be added separately.

In general formula (1d-p), n is an integer of 2 or more, preferably an integer of 2 to 5, and more preferably an integer of 2 to 3.

Specific examples of polyfunctional (meth)acrylic compounds represented by general formula (1b-p) include, but are not limited to, compounds having the following structures. In the following compounds, Y represents a hydrogen atom, a (meth)acryloyl group, or a combination thereof.

Specific examples of polyfunctional (meth)acrylic compounds represented by general formula (1c-p) include, but are not limited to, the following compounds:

In the polymer solution of this embodiment, the polyfunctional (meth)acrylic compound can be blended in an amount that does not affect the effects of the present invention, and the polyfunctional (meth)acrylic compound can be blended in an amount such that the peak area attributable to the polyfunctional (meth)acrylic compound in a gel permeation chromatography (GPC) chart of the resin composition is preferably 10% or less, more preferably 5% or less, and even more preferably 2% or less of the peak area of the resin.

[Monofunctional (meth)acrylic compound]
The polymer solution of the present embodiment may contain a monofunctional (meth)acrylic compound, which is a compound having one (meth)acryloyl group.

Examples of the monofunctional (meth)acrylic compound include compounds represented by the following general formula (2a-m): The monofunctional (meth)acrylic compound may be an unreacted monomer, or may be added separately.
In the general formula (2a-m), the definitions of ^X10 and R are the same as those in the general formula (2a).

Specific examples of compounds represented by 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.

In the polymer solution of this embodiment, the monofunctional (meth)acrylic compound can be blended in an amount that does not affect the effects of the present invention, and the monofunctional (meth)acrylic compound can be blended in an amount such that the peak area attributable to the monofunctional (meth)acrylic compound in a gel permeation chromatography (GPC) chart of the resin composition is preferably 10% or less, more preferably 5% or less, and even more preferably 2% or less of the peak area of the resin.

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

Specific examples of the organic solvent include propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, γ-butyrolactone, N-methylpyrrolidone, cyclohexanone, etc. These may be used alone or in combination of two or more.
The amount of the organic solvent used is not particularly limited, but is used in such an amount that the concentration of the non-volatile components becomes, for example, 10 to 70% by mass, preferably 15 to 60% by mass.

(Preparation of polymer solution)
The polymer solution of the present embodiment can be prepared by mixing the above components by a known method. The polymer solution of the present embodiment is used as a resin material for the photosensitive resin composition described below.

<Photosensitive resin composition>
The photosensitive resin composition of the present embodiment includes the above-mentioned polymer, a polyfunctional (meth)acrylic compound or a monofunctional (meth)acrylic compound added as necessary, and a photosensitizer. That is, the photosensitive resin composition of the present embodiment includes the above-mentioned polymer solution (varnish, resin composition) of the present embodiment and a photosensitizer. Each component will be described below.

[Photosensitizer]
The photosensitizer used in the photosensitive resin composition of the present embodiment includes a photoradical polymerization initiator. Known compounds can be used as the photoradical polymerization initiator, such as 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl 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 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, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, and 2,4-diethylthioxanthone; 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 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-ethoxycarbonylnaphthyl)-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; halomethylated oxadiazole compounds such as 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4-dichlorophenyl)-4,4',5,5'-tetraphenyl-1,2 biimidazole compounds such as 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-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime); titanocene compounds such as bis(η5-2,4-cyclopentadiene-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium; benzoate 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 kinds.
The photoradical polymerization initiator is used in an amount of, for example, 1 to 20 parts by mass, and preferably 3 to 10 parts by mass, per 100 parts by mass of the polymer.

The photosensitive resin composition of this embodiment contains the above components, and thus has high sensitivity in photolithography processing and excellent alkali solubility. Therefore, the photosensitive resin composition has excellent developability and excellent processability in photolithography. In addition, since yellowing of the photosensitive resin composition is suppressed, the article obtained by curing the photosensitive resin composition has transparency.

In the photosensitive resin composition of this embodiment, the polyfunctional (meth)acrylic compound is preferably blended in an amount such that the peak area attributable to the polyfunctional (meth)acrylic compound in a gel permeation chromatography (GPC) chart of the photosensitive resin composition is 5 to 50% of the peak area of the polymer, and more preferably 10 to 35%. By blending the polyfunctional (meth)acrylic compound in the above range, the resulting photosensitive resin composition has excellent alkali solubility.

The photosensitive resin composition of this embodiment may contain, in addition to the above-mentioned polymer, polyfunctional (meth)acrylic compound, and photosensitizer, a compound having one (meth)acryloyl group (monofunctional (meth)acrylic compound). The monofunctional (meth)acrylic compound is the same as that described above. By containing the monofunctional (meth)acrylic compound, the alkali solubility of the obtained photosensitive resin composition is further improved and yellowing is reduced.

When the photosensitive resin composition of this embodiment contains a monofunctional (meth)acrylic compound, the amount of the compound is preferably such that the peak area attributable to the monofunctional (meth)acrylic compound in a gel permeation chromatography (GPC) chart of the photosensitive resin composition is 5 to 50% of the peak area of the polymer, and more preferably 10 to 35%. By adding the monofunctional (meth)acrylic compound in the above range, the resulting photosensitive resin composition has excellent alkali solubility.

In one embodiment, the photosensitive resin composition may contain a colorant. By containing a colorant, the composition can be preferably used as a material for forming a color filter of a liquid crystal display device or a solid-state image sensor. As the colorant, various pigments or dyes can be used.
As the pigment, an organic pigment or an inorganic pigment can be used.

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, pyrromethene pigments, dye lake pigments, etc. can be used.

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

As the dye, for example, known dyes described in JP-A-2003-270428, JP-A-9-171108, JP-A-2008-50599, etc. can be used.
When the photosensitive resin composition contains a colorant, the photosensitive resin composition may contain only one type of colorant, or may contain two or more types of colorants.

Colorants (particularly pigments) with an appropriate average particle size can be used depending on the purpose and application, but when transparency is required, such as in color filters, a small average particle size of 0.1 μm or less is preferred, and when hiding properties are required, such as in paints, a large average particle size of 0.5 μm or more is preferred.

Depending on the purpose and application, the colorant may be surface-treated with rosin, surfactant, resin-based dispersant, pigment derivative, oxide film, silica coating, wax coating, or other treatments.

When the photosensitive resin composition contains a colorant, the amount of the colorant may be set appropriately depending on the purpose and application, but in order to achieve both coloring concentration and dispersion stability of the colorant, the amount of the colorant is preferably 3 to 70 mass %, more preferably 5 to 60 mass %, and even more preferably 10 to 50 mass % of the total non-volatile components (components excluding the solvent) of the photosensitive resin composition.

(Surfactant)
The photosensitive resin composition of the present embodiment may contain a surfactant, and the surfactant is preferably a nonionic surfactant.

By including a nonionic surfactant, the photosensitive resin composition has good coatability when applied to a substrate to obtain a resin film, and a coating film of uniform thickness can be obtained. In addition, residues and pattern lifting during development of the coating film can be prevented.

The nonionic surfactant is, for example, a compound containing a fluorine group (e.g., a fluorinated alkyl group) or a silanol group, or a compound having a siloxane bond as the main skeleton. In this embodiment, it is more preferable to use a nonionic surfactant containing 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 manufactured by DIC Corporation, and Novec FC4430 and FC4432 manufactured by Sumitomo 3M Limited.
When a surfactant is used, the amount of the surfactant added is preferably 0.01 to 10% by weight based on 100 parts by weight of the resin.

(solvent)
The photosensitive resin composition may typically contain a solvent. As the solvent, an organic solvent is preferably used. Specifically, one or more of ketone-based solvents, ester-based solvents, ether-based solvents, alcohol-based solvents, lactone-based solvents, carbonate-based solvents, etc. may be used.

Examples of solvents include propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), ethyl lactate, methyl isobutyl carbinol (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 the solvent used is not particularly limited, but is used in such an amount that the concentration of the non-volatile components becomes, for example, 10 to 70% by mass, preferably 15 to 60% by mass.

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

When the photosensitive resin composition contains a light-blocking agent, the amount of the light-blocking agent may be set appropriately depending on the purpose and application, but in order to achieve both light-blocking performance and dispersion stability of the light-blocking agent, the amount of the light-blocking agent is preferably 3 to 70 mass %, more preferably 5 to 60 mass %, and even more preferably 10 to 50 mass % of the total non-volatile components (components excluding the solvent) of the photosensitive resin composition.

(Crosslinking Agent)
The photosensitive resin composition of the present embodiment may contain a crosslinking agent.
The crosslinking agent is not particularly limited as long as it can crosslink the polymer (can chemically bond with the polymer) by the action of the activated chemical species generated from the photopolymerization initiator.
The crosslinking agent may form a bond by reacting with itself instead of only chemically bonding with the polymer.

The crosslinking agent is preferably, for example, 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 above-mentioned polymer). It is preferable to use a crosslinking agent having the same type of crosslinking group as the crosslinking group (polymerizable double bond) of the polymer in terms of uniform curing property, further improvement of sensitivity, etc.
There is no particular upper limit to the number of functionalities (the number of polymerizable double bonds) per molecule of the crosslinking agent, but it is, for example, 8 or less, and preferably 6 or less.

Specific examples of the crosslinking agent 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 ethylene oxide-added ditrimethylolpropane tetra(meth)acrylate, ethylene oxide-added pentaerythritol tetra(meth)acrylate, ethylene oxide-added dipentaerythritol hexa(meth)acrylate, propylene oxide-added trimethylolpropane tri(meth)acrylate, propylene oxide-added ditrimethylolpropane tetra(meth)acrylate, propylene oxide-added pentaerythritol tetra(meth)acrylate, propylene oxide-added dipentaerythritol hexa(meth)acrylate, ε-caprolactone-added trimethylolpropane tri(meth)acrylate, ε-caprolactone-added ditrimethylolpropane tetra(meth)acrylate, ε-caprolactone-added pentaerythritol tetra(meth)acrylate, and ε-caprolactone-added dipentaerythritol hexa(meth)acrylate;
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 hexavinyl ether, ethylene oxide-added trimethylolpropane trivinyl ether, ethylene oxide-added ditrimethylolpropane tetravinyl ether, ethylene oxide-added pentaerythritol tetravinyl ether, and ethylene oxide-added dipentaerythritol hexavinyl 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-(vinyloxyethoxyethoxyethoxy)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)acrylate;
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 reacting polyfunctional isocyanates, such as tolylene diisocyanate, isophorone diisocyanate, and xylylene diisocyanate, with hydroxyl group-containing (meth)acrylic acid esters, such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate;
Polyfunctional aromatic vinyls such as divinylbenzene;
etc. can be mentioned.

Among these, 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 the photosensitive resin composition contains a crosslinking agent, the photosensitive resin composition may contain only one type of crosslinking agent, or may contain two or more types. When the photosensitive resin composition contains a crosslinking agent, the amount may be appropriately set according to the purpose and application. As an example, the amount of the crosslinking agent may be usually about 30 to 70 parts by mass, preferably about 40 to 60 parts by mass, per 100 parts by mass of the photosensitive resin.

Depending on various purposes and required characteristics, the photosensitive resin composition may contain components such as fillers, binder resins other than the above-mentioned polymers, acid generators, heat resistance improvers, development aids, plasticizers, polymerization inhibitors, UV absorbers, antioxidants, matting agents, defoamers, leveling agents, antistatic agents, dispersants, slip agents, surface modifiers, thixotropic agents, thixotropic aids, silane coupling agents, and polyhydric phenol compounds.

[Films, color filters, black matrices, liquid crystal display devices and solid-state imaging devices]
A patterned film can be obtained by forming a film using the above-mentioned photosensitive resin composition, exposing and developing the film to form a pattern. This film is applied to color filters, black matrices, and the like. That is, a color filter can be obtained by forming a pattern using a photosensitive resin composition containing a colorant. Also, a black matrix can be obtained by forming a pattern using a photosensitive resin composition containing a light-shielding agent. Then, a liquid crystal display device or a solid-state imaging device equipped with a color filter or a black matrix can be manufactured.
A typical procedure for forming a pattern will now be described.

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

The substrate to which the composition is applied is not particularly limited, and examples thereof include a glass substrate, a silicon wafer, a ceramic substrate, an aluminum substrate, a SiC wafer, a GaN wafer, and a copper-clad laminate.
The substrate may be an unprocessed substrate or a substrate having electrodes or elements formed on its surface, and may be surface-treated to improve adhesion.

The method for applying the photosensitive resin composition is not particularly limited. It can be applied by spin coating using a spinner, spray coating using a spray coater, immersion, printing, roll coating, inkjet method, etc.

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

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

(exposure)
Exposure is typically carried out by applying actinic rays to the photosensitive resin film through an appropriate photomask.

Examples of actinic rays include X-rays, electron beams, ultraviolet rays, and visible rays. In terms of wavelength, light of 200 to 500 nm is preferred. In terms of pattern resolution and ease of handling, the light source is preferably g-rays, h-rays, or i-rays from a mercury lamp, and i-rays are particularly preferred. Two or more types of light may be used in combination. As the exposure device, a contact aligner, a mirror projection, or a stepper is preferred.
The amount of light for exposure may be appropriately adjusted depending on the amount of photosensitizer in the photosensitive resin film, and is, for example, about 100 to 500 mJ/cm ² .

After exposure, the photosensitive resin film may be heated again (Post Exposure Bake) if necessary. 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 caused by the radicals generated from the photoradical polymerization initiator, further accelerating the curing reaction.

(developing)
The exposed photosensitive resin film can be developed with an appropriate developer to obtain a pattern, and a substrate having a pattern can be produced.

In the development step, development can be carried out using an appropriate developer, for example, by a dipping method, a paddle method, a rotary spray method, etc. By development, the exposed area (in the case of a positive type) or the unexposed area (in the case of a negative type) of the photosensitive resin film is dissolved and removed, thereby obtaining a pattern.
There is no particular limitation on the type of developer that can be used, and for example, an alkaline aqueous solution or an organic solvent can be used.

Specific examples of the alkaline aqueous solution include: (i) aqueous solutions of inorganic alkali such as sodium hydroxide, sodium carbonate, sodium silicate, and ammonia; (ii) aqueous solutions of organic amines 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 the present embodiment has adjusted alkali solubility and excellent sensitivity, and therefore, when a strongly basic developer such as a TMAH (tetramethylammonium hydroxide) solution is used, a pattern after exposure and development can be formed in a designed shape.

Specific examples of the organic solvent include ketone-based solvents such as cyclopentanone, ester-based solvents such as propylene glycol monomethyl ether acetate (PGMEA) and butyl acetate, and ether-based solvents such as propylene glycol monomethyl ether.
The developer may contain, for example, a water-soluble organic solvent such as methanol or ethanol, a surfactant, or the like.

In this embodiment, it is preferable to use an alkaline aqueous solution as the developer, and it is more preferable to use tetramethylammonium hydroxide, an aqueous sodium carbonate solution, or an aqueous potassium hydroxide solution.
The concentration of the aqueous alkaline solution is preferably 0.1 to 10% by mass, and more preferably 0.5 to 5% by mass.
Through the above steps, a pattern can be obtained/a substrate having a pattern can be manufactured, but various treatments may be carried out after development.

For example, after development, the pattern and the substrate may be washed with a rinse liquid. Examples of the rinse liquid include distilled water, methanol, ethanol, isopropanol, and propylene glycol monomethyl ether. These may be used alone or in combination of two or more.

The pattern thus obtained may be heated to sufficiently harden it. 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, within the range of 15 to 300 minutes. This heat treatment can be performed using a hot plate, an oven, a temperature-programmable heating oven, or the like. The atmospheric gas used in the heat treatment may be air or an inert gas such as nitrogen or argon. Heating may also be performed under reduced pressure.
FIG. 1 shows a schematic diagram of an example of the structure of a liquid crystal display device and/or a solid-state imaging device that includes a color filter and/or a 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 on top of the black matrix 11 and the color filter 12.

The substrate 10 is usually made of a material that transmits light, such as glass, polyester, polycarbonate, polyolefin, polysulfone, a polymer of a cyclic olefin, etc. The substrate 10 may be subjected to a corona discharge treatment, an ozone treatment, a chemical treatment, etc., as necessary.
The substrate 10 is preferably made of glass.
The black matrix 11 is formed, for example, from a cured product of a photosensitive resin composition containing a light-shielding agent.

Color filters 12 usually come in three colors: red, green, and blue. The color filters 12 are made of a cured product of a photosensitive resin composition that contains a colorant corresponding to each color.

The above describes the embodiments of the present invention, but these are merely examples of the present invention, and various configurations other than those described above can be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements that can achieve the object of the present invention are included in the present invention.

The present invention will be described in more detail below with reference to 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; NB: 2-norbornene; MEK: Methyl ethyl ketone; 4-HBA: 4-hydroxybutyl acrylate; HEMA: 2-hydroxyethyl methacrylate; GMA: Glycidyl methacrylate; 4HBAGE: 4-hydroxybutyl acrylate glycidyl ether; 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 Co., Ltd.)

・A-9550: A mixture of the following two compounds. The amount of the compound on the left in the mixture estimated from the hydroxyl value is approximately 50% (manufactured by Shin-Nakamura Chemical Co., Ltd.)

<Synthesis of raw polymer>
(Synthesis of Raw Polymer 1)
353.02 g (3.6 mol) of maleic anhydride, 338.94 g (3.6 mol) of 2-norbornene, and 41.45 g (0.180 mol) of dimethyl 2,2'-azobis(2-methylpropionate) were weighed into a suitable sized reaction vessel equipped with a stirrer and a condenser, and dissolved in a mixed solvent of 578.98 g of methyl ethyl ketone and 113.0 g of toluene to prepare a solution.
Nitrogen was bubbled through this solution for 30 minutes to remove oxygen, and then the solution was heated at 63° C. for 9.5 hours with stirring to polymerize the maleic anhydride and 2-norbornene, producing a polymerized solution.
The polymerization solution obtained above was diluted with 712.92 g of methyl ethyl ketone, and then added dropwise to 8519.9 g of methanol to precipitate a white solid. The obtained white solid was vacuum-dried at a temperature of 120° C. to obtain 550.4 g of a polymer (raw polymer 3) having a structural unit derived from 2-norbornene and a structural unit derived from maleic anhydride.
The resulting polymer was subjected to GPC measurement, and as a result, it was found that the weight average molecular weight Mw was 11,600 and the polydispersity (weight average molecular weight Mw)/(number average molecular weight Mn) was 1.79.

(Synthesis of Raw Material Polymer 2)
353.02 g (3.6 mol) of maleic anhydride, 338.94 g (3.6 mol) of 2-norbornene, and 33.16 g (0.144 mol) of dimethyl 2,2'-azobis(2-methylpropionate) were weighed into a suitable sized reaction vessel equipped with a stirrer and a condenser, and dissolved in a mixed solvent of 1030.1 g of methyl ethyl ketone and 113.0 g of toluene to prepare a solution.
Nitrogen was bubbled through this solution for 30 minutes to remove oxygen, and then the solution was heated at 65° C. for 1.5 hours with stirring, and then further heated at 80° C. for 6 hours to polymerize maleic anhydride and 2-norbornene, thereby producing a polymerization solution.
The polymerization solution obtained above was added dropwise to 8,519.9 g of methanol to precipitate a white solid. The obtained white solid was vacuum-dried at a temperature of 120° C. to obtain 607.5 g of a polymer (raw polymer 2) having a structural unit derived from 2-norbornene and a structural unit derived from maleic anhydride.
The resulting polymer had a weight average molecular weight Mw of 7,000 as measured by gel permeation chromatography (GPC), and the polydispersity (weight average molecular weight Mw)/(number average molecular weight Mn) was 1.82.

[Comparative Example 1]
(Polymer synthesis)
Polymer P1 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). Details are described below.
First, 100.30 g of MEK was added to 60 g of raw polymer 1 (0.312 mol in terms of MA) to prepare a solution. Next, 58.12 g of A-TMM-3LM-N was added to this solution, and then 18.00 g (0.178 mol) of triethylamine was added and reacted at a temperature of 70° C. for 2 hours. After that, 56.27 g (0.390 mol) of 4-HBA was added and reacted at a temperature of 70° C. for 4 hours to prepare a reaction solution.
The reaction solution was diluted with MEK and treated with an aqueous formic acid solution to remove the aqueous phase from the reaction solution. The polymer was then purified by the following procedure.
- The polymer was reprecipitated with excess toluene.
The polymer powder obtained by reprecipitation was washed twice with an excess amount of toluene.
After washing twice, the polymer powder was washed with an excess amount of water three times.
The resulting reaction product was dried at 40°C for 16 hours.
As a result, a polymer P1 was obtained in which the structural units derived from maleic anhydride in the raw polymer were ring-opened with A-TMM-3LM-N and 4-HBA.
The disappearance of the peaks of the polyfunctional (meth)acrylic compound and the monofunctional (meth)acrylic compound used was confirmed by GPC measurement of the polymer P1, which confirmed that the obtained polymer P1 did not contain any unreacted (meth)acrylic compound or any (meth)acrylic compound not having a hydroxyl group.
Table 1 shows the components used in the synthesis examples and the amount of each component charged in terms of maleic anhydride (MA) charged. The amount of each structural unit (mol fraction, mol %) was calculated by ^1H -NMR integral value analysis and is shown in terms of maleic anhydride (MA) charged.
¹ H-NMR measurement confirmed that polymer P1 had a structure ring-opened with A-TMM-3LM-N and 4-HBA.

(Preparation of polymer solution)
The obtained polymer P1 was dissolved in propylene glycol monomethyl ether acetate (PGMEA) to prepare a polymer solution having a solid content concentration of 30% by mass.

(Preparation of Photosensitive Resin Composition)
A photosensitive resin composition was prepared by dissolving the following components in propylene glycol monomethyl ether acetate (PGMEA) so that the total solids concentration was 30% by mass.
Polymer P1: 100 parts by mass Polyfunctional acrylate (dipentaerythritol hexaacrylate): 50 parts by mass Photopolymerization initiator (Ingacure OXE01, manufactured by BASF): 5 parts by mass Adhesion assistant (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.): 1 part by mass Surfactant (F-556, manufactured by DIC Corporation): 0.5 parts by mass If necessary, the obtained photosensitive resin composition was filtered through a PTFE membrane filter Millex-LS (manufactured by Merck Millipore) to remove insoluble matters.

[Comparative Example 2]
(Polymer synthesis)
The MA unit of the raw material polymer 1 was ring-opened with a monofunctional (meth)acrylic compound (HEMA), and then reacted with an epoxy group-containing (meth)acrylic compound (GMA) to prepare a polymer P2. Details are described below.
First, 111.43 g of MEK was added to 60 g of raw polymer 1 (0.312 mol in terms of MA) to prepare a solution. Next, 25.38 g (0.195 mol) of HEMA was added to this solution, and then 6.00 g (0.059 mol) of triethylamine was added and reacted at a temperature of 70° C. for 6 hours. After that, 13.31 g (0.094 mol) of GMA was added and reacted at a temperature of 70° C. for 4 hours to prepare a reaction solution.
The reaction solution was diluted with MEK and treated with an aqueous formic acid solution to remove the aqueous phase from the reaction solution. The polymer was then purified by the following procedure.
- The polymer was reprecipitated with excess 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.
As a result, the structural units derived from maleic anhydride in the raw polymer were ring-opened with HEMA, and reacted with GMA to obtain polymer P2.
The GPC measurement of the polymer P2 confirmed the disappearance of the peaks of the monofunctional (meth)acrylic compound used and . This confirmed that the obtained polymer P2 did not contain any unreacted (meth)acrylic compound or epoxy group-containing (meth)acrylic compound.
Table 1 shows the components used in the synthesis examples and the amounts of each component charged in terms of maleic anhydride (MA). The amounts (molar fraction, mol%) of each structural unit were calculated by ^1H -NMR integral value analysis and are shown in terms of maleic anhydride (MA).
¹ H-NMR measurement confirmed that polymer P2 had a structure ring-opened with HEMA and a structure reacted with GMA.
The polymer solution and the photosensitive resin composition were prepared in the same manner as in Comparative Example 1.

[Example 1]
(Polymer synthesis)
The MA units of the raw material polymer 1 were ring-opened with a trifunctional (meth)acrylic compound (A-TMM-3LM-N) and a monofunctional (meth)acrylic compound (4-HBA), and then reacted with an epoxy group-containing (meth)acrylic compound (GMA) to prepare a polymer P3. Details are described below.
First, 102.63 g of MEK was added to 60 g of raw polymer 1 (0.312 mol in terms of MA) to prepare a solution. Next, 58.12 g of A-TMM-3LM-N was added to this solution, and then 18.00 g (0.178 mol) of triethylamine was added and reacted at a temperature of 70° C. for 2 hours. After that, 27.12 g (0.187 mol) of 4-HBA was added and reacted at a temperature of 70° C. for 4 hours. After that, 13.31 g (0.094 mol) of GMA was added and reacted at a temperature of 70° C. for 4 hours to prepare a reaction solution.
The reaction solution was diluted with MEK and treated with an aqueous formic acid solution to remove the aqueous phase from the reaction solution. The polymer was then purified by the following procedure.
- The polymer was reprecipitated with excess toluene.
The polymer powder obtained by reprecipitation was washed twice with an excess amount of toluene.
After washing twice, the polymer powder was washed with an excess amount of water three times.
The resulting reaction product was dried at 40°C for 16 hours.
As a result, the structural units derived from maleic anhydride in the raw polymer were ring-opened with A-TMM-3LM-N and 4-HBA, and reacted with GMA to obtain polymer P3.
By GPC measurement of the polymer P3, it was confirmed that the peaks of the polyfunctional (meth)acrylic compound, the monofunctional (meth)acrylic compound, and the epoxy group-containing (meth)acrylic compound used disappeared, and it was confirmed that the obtained polymer P3 did not contain any unreacted (meth)acrylic compound, any (meth)acrylic compound not having a hydroxyl group, or any unreacted epoxy group-containing (meth)acrylic compound.
Table 1 shows the components used in the synthesis examples and the amounts of each component charged in terms of maleic anhydride (MA). The amounts (molar fractions, mol%) of each structural unit were calculated by ^1H -NMR integral value analysis and are shown in terms of maleic anhydride (MA).
FIG. 2 shows the ¹ H-NMR chart of polymer P3, and FIG. 3 shows an enlarged portion of the peak near 6.0 ppm.

In addition to the peak corresponding to 3H of an acryloyl group (-CH= _CH2 ) at 5.8-6.7 ppm shown in the ^1H -NMR chart of polymer P3 in FIG. 3, peaks corresponding to 2H of a methacryloyl group (-C( _CH3 )= _CH2 (CH2 of -C( _CH3 )= _CH2 ) appeared at 5.6-5.8 ppm and _6.0-6.1 ppm indicated by x. In the GPC measurement of polymer P3, no peaks corresponding to unreacted trifunctional (meth)acrylic compound (A-TMM-3LM-N), monofunctional (meth)acrylic compound (4-HBA), or epoxy group-containing (meth)acrylic compound (GMA) were observed, which indicates that an acryloyl group and a methacryloyl group derived from GMA were introduced into the polymer.
Furthermore, in GPC measurements of the reaction solution before and after the ring-opening reaction and before and after the GMA addition reaction, the peak derived from the trifunctional (meth)acrylic compound (A-TMM-3LM-N) decreased before and after the ring-opening reaction, and the peak derived from GMA decreased before and after the GMA addition reaction, which indicates that A-TMM-3LM-N and GMA were introduced into the polymer.

[Example 2]
(Polymer synthesis)
The MA unit of the raw material polymer 1 was ring-opened with a trifunctional (meth)acrylic compound (A-TMM-3LM-N), further ring-opened by adding water, and then reacted with an epoxy group-containing (meth)acrylic compound (GMA) to prepare the polymer P4. Details are described below.
First, 103.92 g of MEK was added to 60 g of raw polymer 1 (0.312 mol in terms of MA) to prepare a solution. Next, 58.12 g of A-TMM-3LM-N was added to this solution, and then 18.00 g (0.178 mol) of triethylamine was added and reacted at a temperature of 70° C. for 2 hours. After that, 1.50 g (0.083 mol) of water was added and reacted at a temperature of 70° C. for 2 hours. After that, 26.62 g (0.187 mol) of GMA was added and reacted at a temperature of 70° C. for 4 hours to prepare a reaction solution.
The reaction solution was diluted with MEK and treated with an aqueous formic acid solution to remove the aqueous phase from the reaction solution. The polymer was then purified by 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.
After washing twice, the polymer powder was washed with an excess amount of water three times.
The resulting reaction product was dried at 40°C for 16 hours.
As a result, the structural units derived from maleic anhydride in the raw polymer were ring-opened with A-TMM-3LM-N and water, and reacted with GMA to obtain polymer P4.
By GPC measurement of the polymer P3, it was confirmed that the peaks of the polyfunctional (meth)acrylic compound and the epoxy group-containing (meth)acrylic compound used disappeared, and it was confirmed that the obtained polymer P4 did not contain any unreacted (meth)acrylic compound, any (meth)acrylic compound not having a hydroxyl group, or any unreacted epoxy group-containing (meth)acrylic compound.
The polymer solution and the photosensitive resin composition were prepared in the same manner as in Comparative Example 1.

[Example 3]
Polymer P5 was produced in the same manner as in Example 2 except that the amounts of the raw materials added were changed as shown in Table 1. The polymer solution and the photosensitive resin composition were prepared in the same manner as in Comparative Example 1.
By GPC measurement of the prepared polymer P5, it was confirmed that the peaks of the polyfunctional (meth)acrylic compound and the epoxy group-containing (meth)acrylic compound used disappeared. This confirmed that the obtained polymer P5 did not contain any unreacted (meth)acrylic compound, any (meth)acrylic compound not having a hydroxyl group, or any unreacted epoxy group-containing (meth)acrylic compound.

[Example 4]
(Polymer synthesis)
The MA unit of the raw material polymer 1 was ring-opened with a pentafunctional (meth)acrylic compound and a monofunctional (meth)acrylic compound (4-HBA), and then reacted with an epoxy group-containing (meth)acrylic compound (GMA) to prepare the polymer P6. Details are described below.
First, 102.36 g of MEK was added to 60 g of raw polymer 1 (0.312 mol in terms of MA) to prepare a solution. Next, 52.54 g of A-9550 was added to this solution, and then 18.00 g (0.178 mol) of triethylamine was added and reacted at a temperature of 70° C. for 2 hours. Further, 56.27 g (0.390 mol) of 4-HBA was added and reacted at a temperature of 70° C. for 4 hours. Further, 26.62 g (0.187 mol) of GMA was added and reacted at a temperature of 70° C. for 4 hours to prepare a reaction solution.
The reaction solution was diluted with MEK and treated with an aqueous formic acid solution to remove the aqueous phase from the reaction solution. The polymer was then purified by the following procedure.
- The polymer was reprecipitated with excess toluene.
The polymer powder obtained by reprecipitation was washed twice with an excess amount of toluene.
After washing twice, the polymer powder was washed with an excess amount of water three times.
The resulting reaction product was dried at 40°C for 16 hours.
As a result, the structural units derived from maleic anhydride in the raw polymer were ring-opened with A-9550 and 4-HBA, and polymer P6 was obtained in which the structural units were reacted with GMA.
By GPC measurement of the polymer P6, it was confirmed that the peaks of the polyfunctional (meth)acrylic compound, the monofunctional (meth)acrylic compound, and the epoxy group-containing (meth)acrylic compound used disappeared, and it was confirmed that the obtained polymer P6 did not contain any unreacted (meth)acrylic compound, any (meth)acrylic compound not having a hydroxyl group, or any unreacted epoxy group-containing (meth)acrylic compound.
The polymer solution and the photosensitive resin composition were prepared in the same manner as in Comparative Example 1.

[Example 5]
Polymer P7 was produced in the same manner as in Example 4 except that the amounts of the raw materials added were changed as shown in Table 1. The polymer solution and the photosensitive resin composition were prepared in the same manner as in Comparative Example 1.

[Example 6]
(Polymer synthesis)
The MA unit of the raw material polymer 1 was ring-opened with a trifunctional (meth)acrylic compound (A-TMM-3LM-N) and a monofunctional (meth)acrylic compound (HEMA), and then reacted with an epoxy group-containing (meth)acrylic compound (GMA) to prepare the polymer P8. Details are described below.
First, 102.26 g of MEK was added to 60 g of raw polymer 1 (0.312 mol in terms of MA) to prepare a solution. Next, 58.12 g of A-TMM-3LM-N was added to this solution, and then 18.00 g (0.178 mol) of triethylamine was added and reacted at a temperature of 70° C. for 2 hours. After that, 50.78 g (0.390 mol) of HEMA was added and reacted at a temperature of 70° C. for 4 hours. After that, 26.62 g (0.187 mol) of GMA was added and reacted at a temperature of 70° C. for 4 hours to prepare a reaction solution.
The reaction solution was diluted with MEK and treated with an aqueous formic acid solution to remove the aqueous phase from the reaction solution. The polymer was then purified by the following procedure.
- The polymer was reprecipitated with excess toluene.
The polymer powder obtained by reprecipitation was washed twice with an excess amount of toluene.
After washing twice, the polymer powder was washed with an excess amount of water three times.
The resulting reaction product was dried at 40°C for 16 hours.
As a result, the structural units derived from maleic anhydride in the raw polymer were ring-opened with A-TMM-3LM-N and HEMA, and reacted with GMA to obtain polymer P8.
By GPC measurement of the polymer P8, it was confirmed that the peaks of the polyfunctional (meth)acrylic compound, the monofunctional (meth)acrylic compound, and the epoxy group-containing (meth)acrylic compound used disappeared, and it was confirmed that the obtained polymer P8 did not contain any unreacted (meth)acrylic compound, any (meth)acrylic compound not having a hydroxyl group, or any unreacted epoxy group-containing (meth)acrylic compound.
The polymer solution and the photosensitive resin composition were prepared in the same manner as in Comparative Example 1.

[Example 7]
Polymer P9 was produced in the same manner as in Example 6 except that the amounts of the raw materials added were changed as shown in Table 1. The polymer solution and the photosensitive resin composition were prepared in the same manner as in Comparative Example 1.
By GPC measurement of the polymer P9, it was confirmed that the peaks of the polyfunctional (meth)acrylic compound, the monofunctional (meth)acrylic compound, and the epoxy group-containing (meth)acrylic compound used disappeared, and it was confirmed that the obtained polymer P9 did not contain any unreacted (meth)acrylic compound, any (meth)acrylic compound not having a hydroxyl group, or any unreacted epoxy group-containing (meth)acrylic compound.

[Example 8]
(Polymer synthesis)
The MA unit of the raw material polymer 1 was ring-opened with a trifunctional (meth)acrylic compound (A-TMM-3LM-N) and a monofunctional (meth)acrylic compound (4-HBA), and then reacted with an epoxy group-containing (meth)acrylic compound (4HBAGE) to prepare a polymer P10. Details are described below.
First, 99.49 g of MEK was added to 60 g of raw polymer 1 (0.312 mol in terms of MA) to prepare a solution. Next, 58.12 g of A-TMM-3LM-N was added to this solution, and then 18.00 g (0.178 mol) of triethylamine was added and reacted at a temperature of 70° C. for 2 hours. After that, 56.27 g (0.390 mol) of 4-HBA was added and reacted at a temperature of 70° C. for 4 hours. After that, 28.13 g (0.140 mol) of 4HBAGE was added and reacted at a temperature of 70° C. for 4 hours to prepare a reaction solution.
The reaction solution was diluted with MEK and treated with an aqueous formic acid solution to remove the aqueous phase from the reaction solution. The polymer was then purified by 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.
After washing twice, the polymer powder was washed with an excess amount of water three times.
The resulting reaction product was dried at 40°C for 16 hours.
As a result, the structural units derived from maleic anhydride in the raw polymer were ring-opened with A-TMM-3LM-N and 4-HBA, and polymer P10 was obtained which had been reacted with 4HBAGE.
By GPC measurement of the polymer P10, it was confirmed that the peaks of the polyfunctional (meth)acrylic compound, the monofunctional (meth)acrylic compound, and the epoxy group-containing (meth)acrylic compound used disappeared, and it was confirmed that the obtained polymer P10 did not contain any unreacted (meth)acrylic compound, any (meth)acrylic compound not having a hydroxyl group, or any unreacted epoxy group-containing (meth)acrylic compound.
The polymer solution and the photosensitive resin composition were prepared in the same manner as in Comparative Example 1.

[Example 9]
(Polymer synthesis)
The MA unit of the raw material polymer 2 was ring-opened with a trifunctional (meth)acrylic compound (A-TMM-3LM-N), and then reacted with an epoxy group-containing (meth)acrylic compound (GMA) to prepare a polymer P11. Details are described below.
First, 100.57 g of MEK was added to 60 g of raw polymer 2 (0.312 mol in terms of MA) to prepare a solution. Next, 58.12 g of A-TMM-3LM-N was added to this solution, and then 18.00 g (0.178 mol) of triethylamine was added and reacted at a temperature of 70° C. for 2 hours. After that, 13.31 g (0.094 mol) of GMA was added and reacted at a temperature of 70° C. for 4 hours to prepare a reaction solution.
The reaction solution was diluted with MEK and treated with an aqueous formic acid solution to remove the aqueous phase from the reaction solution. The polymer was then purified by 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.
After washing twice, the polymer powder was washed with an excess amount of water three times.
The resulting reaction product was dried at 40°C for 16 hours.
As a result, the structural unit derived from maleic anhydride in the raw polymer was ring-opened with A-TMM-3LM-N, and reacted with GMA to obtain polymer P11.
By GPC measurement of the polymer P11, it was confirmed that the peaks of the polyfunctional (meth)acrylic compound, the monofunctional (meth)acrylic compound, and the epoxy group-containing (meth)acrylic compound used disappeared, and it was confirmed that the obtained polymer P11 did not contain any unreacted (meth)acrylic compound, any (meth)acrylic compound not having a hydroxyl group, or any unreacted epoxy group-containing (meth)acrylic compound.
The polymer solution and the photosensitive resin composition were prepared in the same manner as in Comparative Example 1.

<Evaluation method>
The polymers, polymer solutions, and photosensitive resin compositions synthesized in the Examples and Comparative Examples were evaluated as follows. The results are shown in Tables 1 and 2.

(Weight average molecular weight (Mw)/molecular weight distribution (PDI))
The weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution (PDI: Mw/Mn) are polystyrene equivalent values obtained from a calibration curve of standard polystyrene (PS) obtained by GPC measurement. The measurement conditions are as follows. The results are shown in Table 1.
Tosoh gel permeation chromatography device HLC-8320GPC
Column: TSK-GEL Supermultipore HZ-M manufactured by Tosoh Corporation
Detector: RI detector for liquid chromatography Measurement temperature: 40°C
Solvent: THF
Sample concentration: 2.0 mg/ml

(Acid value)
The acid value of the polymer was measured by the following method.
Approximately 50 mg of the polymer and approximately 5 mg of dimethyl terephthalate as an internal standard were weighed and dissolved in DMSO-d6. This solution was subjected to ¹ H-NMR measurement using a nuclear magnetic resonance spectrometer JNM-AL300 (manufactured by ^JEOL ). The amount of carboxyl groups was calculated from the integral value of the H peak (near 12.4 ppm) of the carboxyl group (-COOH) of the polymer, based on the integral value of the 4H peak (near 8.1 ppm) of the phenyl group of dimethyl terephthalate, the internal standard for 1 H-NMR measurement. The acid value (mg KOH/g) can then be calculated from the amount. The larger the acid value, the greater the amount of carboxyl groups per unit mass of the polymer.
The results are shown in Table 1. When the acid value is 70 gKOH/g or more, it can be considered that the polymer has a carboxy group necessary for the polymer to have sufficient developability.

(Double bond equivalent)
The double bond equivalent of the polymer was measured by the following method.
^{The 1} H-NMR measurement was carried out in the same manner as in the above-mentioned method for measuring the acid value. The amount of acryloyl groups in the polymer (mol/g) was calculated from the integral ratio of the signal (5.6-5.8 ppm, 3H) derived from the acryloyl group in the obtained spectrum chart to the signal (8.1 ppm, 4H) derived from the phenyl group of the internal standard substance, and the amount of methacryloyl groups in the polymer (mol/g) was calculated from the integral ratio of the signal (5.6-5.8 ppm, 2H) derived from the methacryloyl group to the signal (8.1 ppm, 4H) derived from the phenyl group of the internal standard substance. Here, the signal derived from the methacryloyl group at 6.0-6.1 ppm was weak and overlapped with the signal of the acryloyl group, 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 calculated amount of acryloyl groups (mol/g) and methacryloyl groups (mol/g) in the polymer, and the double bond equivalent (g/mol) was calculated from the amount of double bonds.
The results are shown in Table 1. A smaller value of the double bond equivalent indicates a larger amount of C=C double bonds per unit mass of the polymer. A double bond equivalent of 450 g/mol or less can be regarded as (a density of double bonds required for high sensitivity is present in the polymer).

(Developability Evaluation (Dissolution Rate of Polymer (or Photosensitive Resin Composition) in Alkaline Developer))
The polymer solutions (or photosensitive resin compositions) obtained in the Examples and Comparative Examples were spin-coated onto a wafer, the PGMEA was dried, and the wafer was pre-baked at a temperature of 100° C. for 2 minutes to prepare resin films having a thickness of 2 μm±0.2 μm.
This resin film was immersed together with the wafer in a 2.38% by mass aqueous solution of TMAH 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 until the resin film was dissolved and the interference pattern disappeared, and dividing the film thickness by the time. The results are shown in Table 1. If the alkaline dissolution rate of the polymer solution is 200 nm/s or more and 2000 nm/s or less, the developability and reproducibility of the pattern shape can be considered good. If the alkaline dissolution rate of the photosensitive resin composition is 200 nm/s or more and 2500 nm/s or less, the developability and reproducibility of the pattern shape can be considered good.

[Sensitivity evaluation of photosensitive resin composition (2.38% by mass TMAH aqueous solution)]
(Exposure Amount at Which Residual Film Rate is 90% or More)
The photosensitive resin compositions obtained in the Examples and Comparative Examples were spin-coated on a 3-inch silicon wafer that had been treated with HMDS (hexamethyldisilazane), and baked on a hot plate at 100° C. for 120 seconds to obtain a thin film A having 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/cm ² using a photomask having a gradation of light shielding rate of 1 to 100% using a g+h+i ray mask aligner (PLA-501F) manufactured by Canon Inc.
After exposure, the thin film was developed in a 2.38 mass% TMAH (tetramethylammonium hydroxide) aqueous solution at 23°C for 10 seconds (only in Example 1, development was performed for 5 seconds, with the wafer immersed), to obtain a thin film B exposed and developed at each exposure dose of ¹ to 100 mJ/cm2.
From the film thicknesses of the thin films A and B obtained by the above method, the remaining film ratio was calculated according to the following formula.
Remaining film rate (%)=(film thickness of thin film B at each exposure dose/film thickness of thin film A)×100
The exposure dose at which the residual film ratio was 90% or more was defined as the sensitivity of each photosensitive resin composition. The results are shown in Table 2. If the exposure dose at which the residual film ratio was 90% or more was 20 mJ/ ^cm2 or less, the photosensitive composition could be used without any problems.

(Exposure Amount at Which Residual Film Rate is 95% or More)
The photosensitive resin compositions obtained in the Examples and Comparative Examples were spin-coated on a 3-inch silicon wafer that had been treated with HMDS (hexamethyldisilazane), and baked on a hot plate at 100° C. for 120 seconds to obtain a thin film A having 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/cm ² using a photomask having a gradation of light shielding rate of 1 to 100% using a g+h+i ray mask aligner (PLA-501F) manufactured by Canon Inc.
After exposure, the thin film was developed in a 2.38 mass% TMAH (tetramethylammonium hydroxide) aqueous solution at 23°C for 10 seconds (only in Example 1, development was performed for 5 seconds, with the wafer immersed), to obtain a thin film B exposed and developed at each exposure dose of ¹ to 100 mJ/cm2.
From the film thicknesses of the thin films A and B obtained by the above method, the remaining film ratio was calculated according to the following formula.
Remaining film rate (%)=(film thickness of thin film B at each exposure dose/film thickness of thin film A)×100
The exposure dose at which the residual film ratio was 95% or more was defined as the sensitivity of each photosensitive resin composition. The results are shown in Table 3. If the exposure dose at which the residual film ratio was 95% or more was 20 mJ/ ^cm2 or less, the photosensitive composition could be used without any problems.

The polymers synthesized in Examples 1 to 9 all had structural units represented by general formula (1-1) and structural units represented by general formula (1-2) in their polymer structures, and had good alkaline dissolution rates and therefore excellent developability. Furthermore, the polymers had excellent sensitivity. Therefore, it was estimated that the photosensitive resin compositions containing the polymers synthesized in Examples 1 to 9 had a good balance between developability and sensitivity, and that even when a strong basic developer was used, the patterns after exposure and development would have the designed shape.

<Preparation of Color Filter>
A suitable amount of pigment dispersion NX-061 (manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd., green) was further added to the photosensitive resin compositions prepared in Examples 1 to 9 to prepare colored photosensitive resin compositions.
This was formed into a film on a substrate, and then exposed to light and developed with an alkali to form a green color filter.

In addition, by using the company's NX-053 (blue) or NX-032 (red) as the pigment dispersion liquid instead of NX-061, it was possible to form blue or red color filters.

<Preparation of Black Matrix>
A suitable amount of carbon black dispersion NX-595 (manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) was further added to the photosensitive resin compositions prepared in Examples 1 to 9 to prepare black photosensitive resin compositions.
This was applied to a substrate as a film, and then exposed to light and developed with an alkaline solution to form a black matrix.

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

Claims (17)

A polymer comprising a structural unit represented by the following general formula (2), a structural unit represented by the following general formula (1-1), and a structural unit represented by the following general formula (1-2):

(In general formula (2), R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom or an organic group having 1 to 30 carbon atoms, and a1 is 0, 1 or 2.)

(In general formula (1-1), 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 is an oxygen atom or a substituted or unsubstituted alkylene group having 1 to 4 carbon atoms, and the alkyl group of Q and any carbon atom of the alkylene group of X may be bonded to form a ring. In general formula (1-2), R ^D is a group containing a polyfunctional (meth)acryloyl group.) The polymer according to claim 1 , wherein Z comprises a group represented by the following general formula (1a):

(In general formula (1a), R is a hydrogen atom or a methyl group.) 3. The polymer according to claim 1 , wherein R ^D comprises at least one group containing 2 to 6 (meth)acryloyl groups. The polymer according to any one of claims 1 to 3 , wherein the R ^D contains at least one group represented by the following general formula (1b), (1c) or (1d):

(In general 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.
X ¹ is a single bond, an alkylene group having 1 to 6 carbon atoms, or a group represented by -Z-X- (Z is -O- or -OCO-, and X is an alkylene group having 1 to 6 carbon atoms), and a plurality of X ^1s may be the same or different;
X ¹ ' is a single bond, an alkylene group having 1 to 6 carbon atoms or a group represented by -X'-Z'- (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 having 1 to 12 carbon atoms.

(In general formula (1c),
k, R, ^X1 and ^X2 are respectively defined as R, k, ^X1 and ^X2 in the general formula (1b), a plurality of R may be the same or different from each other, a plurality of ^X1 may be the same or different from each other,
^X3 is a divalent organic group having 1 to 6 carbon atoms;
^X4 and ^X5 each independently represent 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.

(In general formula (1d), n is an integer of 2 to 5.) The polymer according to any one of claims 1 to 4 , comprising a structural unit represented by the following general formula (1):

(In formula (1), Q, X, and Z are the same as those in formula (1-1), and R ^D is the same as those in formula (1-2).) The polymer according to any one of claims 1 to 5 , further comprising a structural unit represented by the following general formula (3-1):

(In general formula (3-1), R 1 ^S is a group containing only one (meth)acryloyl group.) The polymer according to any one of claims 1 to 6 , further comprising a structural unit represented by the following general formula (4):

The polymer according to any one of claims 1 to 7 , further comprising a structural unit represented by the following general formula (5):

(In formula (5), Q, X and Z are the same as those in formula (1-1).) The polymer according to any one of claims 1 to 8 , further comprising a structural unit represented by the following general formula (6):

(In the general formula (6), Q, X, and Z have the same meanings as in the general formula (1-1). A plurality of Z's, a plurality of Q's, and a plurality of X's may be the same or different.) The polymer according to any one of claims 1 to 9 , further comprising a structural unit represented by the following general formula (MA):

The polymer according to any one of claims 1 to 10 , having an acid value of 70 mg KOH/g or more and 150 mg KOH/g or less. A polymer solution comprising the polymer according to any one of claims 1 to 11 . The polymer solution according to claim 12 , which is used to form a color filter or a black matrix. A polymer solution according to claim 12 ;
A polyfunctional (meth)acrylate monomer;
A photopolymerization initiator;
A photosensitive resin composition comprising: The photosensitive resin composition according to claim 14 , further comprising a surfactant. A cured product of the photosensitive resin composition according to claim 14 or 15 . A film comprising the cured product of claim 16 .

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