JP7552223B2 - Polymer, polymer manufacturing method, photosensitive resin composition, and cured product - Google Patents

Description

The present invention relates to a polymer, a method for producing the polymer, a photosensitive resin composition containing the polymer, and a cured product formed from the photosensitive resin composition. More specifically, the present invention relates to a polymer used for producing a color filter or a black matrix, a method for producing the polymer, and uses thereof.

Liquid crystal display devices and solid-state imaging devices are usually equipped with color filters and black matrices. Color filters and black matrices are configured by forming structures such as colored patterns and protective films on a substrate. The main method for forming colored patterns and protective films among these structures is to form them by photolithography using a photosensitive resin composition. Various studies have been conducted on photosensitive resin compositions. For example, Patent Document 1 describes a photosensitive resin composition containing an alkali-soluble resin having at least a group having an acidic group and two or more different polymerizable unsaturated groups in the side chain, 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.

International Publication No. 2012/147706

Photosensitive resin compositions for forming color filters and black matrices use resins that undergo polymerization reactions and harden when exposed to light. Color filters and black matrices are produced by patterning a photosensitive resin composition through exposure and development, and then hardening it. Although "high sensitivity" is considered a common issue for photosensitive resin compositions, there is a demand for even higher levels of sensitivity due to the increasing complexity and popularity of display devices and imaging devices. The higher the sensitivity of the photosensitive resin composition, the shorter the time required for exposure, which can improve productivity. In addition, photosensitive resin compositions are required to have excellent processability in photolithography using an alkaline developer.

The inventors discovered that by improving the polymer used in the photosensitive resin composition, a photosensitive resin composition having good sensitivity and high alkali solubility, and therefore excellent developability, can be obtained, and thus arrived at the present invention.

According to the present invention, there is provided a polymer comprising a structural unit represented by formula (NB), a structural unit represented by formula (1), a structural unit represented by formula (2), and a structural unit represented by formula (3).

（式（ＮＢ）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、ａ_１は０、１または２である。）

(In formula (NB), 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 a ₁ is 0, 1 or 2.)

（式（１）中、Ｒ^ｐは、２以上の（メタ）アクリロイル基を有する基である。）

(In formula (1), R ^p is a group having two or more (meth)acryloyl groups.)

（式（２）中、Ｒ^ｓは、１つの（メタ）アクリロイル基を有する基である。）

(In formula (2), ^Rs is a group having one (meth)acryloyl group.)

According to the present invention, there is also provided a method for producing a polymer containing a structural unit represented by formula (NB), a structural unit represented by formula (1), a structural unit represented by formula (2), and a structural unit represented by formula (3), comprising the steps of:
A first step of preparing a polymer precursor including a structural unit represented by formula (NB), a structural unit represented by formula (1), a structural unit represented by formula (2), and a structural unit represented by formula (MA);
A method for producing a polymer is provided which comprises a second step of treating the polymer precursor with water in the presence of a catalyst.

（式（ＮＢ）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、ａ_１は０、１または２である。）

(In formula (NB), 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 a ₁ is 0, 1 or 2.)

（式（１）中、Ｒ^ｐは、２以上の（メタ）アクリロイル基を有する基である。）

(In formula (1), R ^p is a group having two or more (meth)acryloyl groups.)

（式（２）中、Ｒ^ｓは、１つの（メタ）アクリロイル基を有する基である。）

(In formula (2), ^Rs is a group having one (meth)acryloyl group.)

The present invention also provides a photosensitive resin composition containing the above polymer and a photoradical polymerization initiator.

Furthermore, the present invention provides a cured product formed from the above photosensitive resin composition.

The present invention provides a polymer that is used to produce a photosensitive resin composition that has good sensitivity and excellent developability.

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 ¹³ C-NMR chart of polymer P13 obtained in Example 13. 1 is a ¹³ C-NMR chart of polymer P14 obtained in Example 14.

The following describes an embodiment of the present invention with reference to the drawings. In all drawings, similar components are given similar reference symbols and descriptions are omitted as appropriate. In addition, all drawings are for explanatory purposes only. The shapes and dimensional ratios of each member in the drawings do not necessarily correspond to actual articles. 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, "1-5 mol%" means "1 mol% or more and 5 mol% 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 includes 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 of this embodiment (hereinafter referred to as "polymer P") contains a structural unit represented by formula (NB), a structural unit represented by formula (1), a structural unit represented by formula (2), and a structural unit represented by formula (3). These structural units typically constitute the main chain of polymer P.

式（ＮＢ）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、ａ_１は０、１または２である。

In formula (NB), 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; a ₁ is 0, 1 or 2.

式（１）中、Ｒ^ｐは、２以上の（メタ）アクリロイル基を有する基である。

In formula (1), R ^p is a group having two or more (meth)acryloyl groups.

式（２）中、Ｒ^ｓは、１つの（メタ）アクリロイル基を有する基である。

In formula (2), R ^s is a group having one (meth)acryloyl group.

Since polymer P contains a structural unit represented by formula (1) and a structural unit represented by formula (2), a photosensitive resin composition containing this has excellent sensitivity when subjected to a photolithography method. This is thought to be because the (meth)acryloyl group contained in the structural units represented by formula (1) and formula (2) promotes the curing reaction (polymerization reaction). In addition, polymer P has high alkali solubility due to the structural unit represented by formula (3). As a result, a photosensitive resin composition containing polymer P has excellent developability when subjected to a photolithography method using an alkaline aqueous solution as a developer. In addition, the structural unit represented by formula (NB) is chemically robust. Therefore, polymer P containing this as a part of the structural unit has small weight loss and is stable when heated during the manufacture of a liquid crystal display device or a solid-state imaging device.

In addition to the above structural units, the polymer P of this embodiment may contain a structural unit represented by formula (MA). The structural unit represented by formula (MA) is ring-opened by an alkaline developer to generate two carboxyl groups. Therefore, the polymer P has excellent developability. When the polymer P contains a structural unit represented by formula (MA), the structural unit represented by formula (MA) preferably accounts for 3 to 40 mol %, and more preferably 10 to 30 mol %, of all structural units of the polymer P.

In the structural unit represented by formula (NB) constituting polymer P, examples of the organic group having 1 to 30 carbon atoms which may 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 formula (NB), 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 group 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 a fluorine atom, a hydroxyl group, a carboxyl group, 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 formula (NB), _a1 is preferably 0 or 1, more preferably 0.

The proportion of the structural units represented by formula (NB) 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 %.

In the structural unit represented by formula (1) constituting the polymer P, R ^p 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 ^p , the sensitivity of the polymer P containing it can be further increased. In addition, it becomes easier to achieve a high degree of compatibility between sensitivity and developability. Furthermore, heat resistance can be improved.
From the viewpoint of further improving the sensitivity and of preventing steric hindrance, it is preferred that R ^p contains two or more acryloyl groups (groups represented by -C(=O)-CH= _CH2 ).

式（１ｂ）中、
ｋは２または３であり、
Ｒは水素原子またはメチル基であり、複数のＲは同じでも異なっていてもよく、
Ｘ^１は単結合、炭素数１～６のアルキレン基または－Ｚ－Ｘ－で表される基（Ｚは－Ｏ－または－ＯＣＯ－であり、Ｘは炭素数１～６のアルキレン基である）であり、複数存在するＸ^１は同一であっても異なっていてもよく、
Ｘ^１'は単結合、炭素数１～６のアルキレン基または－Ｘ'－Ｚ'－で表される基（Ｘ'は炭素数１～６のアルキレン基であり、Ｚ'は－Ｏ－または－ＣＯＯ－である）であり、
Ｘ^２は炭素数１～１２のｋ＋１価の有機基である。 R ^p is preferably a group represented by formula (1b), a group represented by formula (1c), or a group represented by formula (1d). By using such a group, the above-mentioned various effects tend to be easily obtained.

In formula (1b),
k is 2 or 3;
R is a hydrogen atom or a methyl group, and multiple Rs may be the same or different.
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 even more 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 described 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 formula (1c),
k, R, ^X1 , and ^X2 are the same as R, k, ^X1, and ^X2 in formula (1b), respectively, a plurality of R may be the same or different, and a plurality of ^X1 may be the same or different;
^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.

式（１ｄ）中、ｎは、２～５の整数であり、好ましくは、２または３である。
Ｒの具体的態様、好ましい態様などについては、一般式（１ｂ）で説明したものと同様である。

In formula (1d), n is an integer of 2 to 5, and preferably 2 or 3.
Specific and preferred embodiments of R are the same as those explained in relation to formula (1b).

The proportion of the structural unit represented by formula (1) in all structural units of polymer P is preferably 3 to 40 mol %, more preferably 3 to 30 mol %.

In the structural unit represented by formula (2) constituting the polymer P, R 1 ^S is a group containing only one (meth)acryloyl group. By including both the structural unit of formula (1) containing two or more (meth)acryloyl groups and the structural unit of formula (2) containing only one acryloyl group in the polymer P, it is possible to achieve a higher compatibility between sensitivity and developability. In particular, in the design of a normal 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, while when the developability is improved, the curing tends to be insufficient. However, the polymer P of this embodiment has both sensitivity and developability in a good balance.

More specifically, R 1 ^S is a group represented by the following formula (2a).

式（２ａ）において、Ｘ^１０は２価の有機基であり、Ｒは水素原子またはメチル基である。
Ｘ^１０の総炭素数は、好ましくは１～３０、より好ましくは１～２０である、さらに好ましくは１～１０である。
式（２ａ）において、Ｘ^１０は２価の有機基であり、Ｒは水素原子またはメチル基である。
Ｘ^１０の総炭素数は、好ましくは１～３０、より好ましくは１～２０である、さらに好ましくは１～１０である。
Ｘ^１０の２価の有機基としては、例えばアルキレン基が好ましい。このアルキレン基中の一部の－ＣＨ_２－はエーテル基（－Ｏ－）となっていてもよい。アルキレン基は、直鎖状でも分枝状でもよいが、直鎖状であることがより好ましい。

In formula (2a), ^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 (2a), ^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 formula (2) 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.

The proportion of the structural unit represented by formula (2) in all structural units of the polymer P is preferably from 5 to 40 mol %, more preferably from 10 to 30 mol %.
In addition, in the polymer P of the present embodiment, the total content of the structural unit represented by formula (1) and the structural unit represented by formula (2) is preferably 5 to 60 mol %, more preferably 10 to 50 mol %, and even more preferably 10 to 40 mol %, based on the total structural units of the polymer P.

The polymer P of this embodiment contains a structural unit represented by formula (3). This gives the polymer P excellent solubility in an alkaline developer and therefore excellent developability.

The proportion of the structural unit represented by formula (3) in all structural units of polymer P is preferably 1 to 10 mol %, more preferably 2 to 7 mol %.

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 the polymer, 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 of the present embodiment is preferably 1000 to 80000, more preferably 2000 to 40000, and further preferably 3000 to 30000. By appropriately adjusting the weight average molecular weight, it is possible to adjust the sensitivity and the solubility in an alkaline developer.
The dispersity (weight average molecular weight Mw/number average molecular weight Mn) of the polymer P of the present embodiment is preferably 1.0 to 5.0, more preferably 1.0 to 4.0, and even more preferably 1.0 to 3.0. By appropriately adjusting the dispersity, the physical properties of the polymer P can be made uniform, 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 the polymer P of this embodiment is preferably 150 to 250°C, more preferably 170 to 230°C. The polymer P of this embodiment tends to have a high glass transition temperature due to the inclusion of structural units of formula (NB). This is preferable in that the pattern formed on the substrate can be stable when manufacturing a liquid crystal display device or a solid-state imaging device. The glass transition temperature can be determined, for example, by differential thermal analysis (DTA).

By having the above-mentioned configuration, the polymer P of this embodiment can have an alkali dissolution rate of 150 nm/s or more, preferably 180 nm/s or more, and more preferably 200 nm/s or more. The upper limit is not particularly limited, but can be, for example, 500 nm/s or less. In the present specification, the alkali dissolution rate is a value measured under the following conditions.
(Method of measuring alkaline dissolution rate) Polymer P is dissolved in propylene glycol monomethyl ether acetate (PGMEA) to prepare a solution with a solid concentration of 30 mass%. The obtained polymer solution is then spin-coated on a wafer, the PGMEA is dried, and the wafer is pre-baked at a temperature of 100°C for 2 minutes to prepare a resin film with a thickness of 2 μm±0.2. The resin film is immersed together with the wafer in a 2.0 mass% aqueous sodium carbonate solution at a temperature of 23°C. The immersed wafer is visually observed to measure the time until the resin film dissolves and the interference pattern disappears, and the alkali dissolution rate (μm/sec) is calculated by dividing the film thickness (2 μm±0.2) before immersion by that time.

(Method for producing polymer P)
The polymer P of this embodiment can be produced (synthesized) by any method.
(I) a first step of preparing a polymer precursor (hereinafter referred to as "polymer precursor P'") comprising a structural unit represented by the above formula (NB), a structural unit represented by the above formula (1), a structural unit represented by the above formula (2), and a structural unit represented by the above formula (MA);
(II) the second step of treating the polymer precursor obtained in the first step with water in the presence of a catalyst, thereby producing a polymer P comprising the structural unit represented by the above formula (NB), the structural unit represented by the above formula (1), the structural unit represented by the above formula (2), and the structural unit represented by the above formula (3), and optionally comprising the structural unit represented by the above formula (MA).

Hereinafter, the method for producing (synthesizing) the polymer of this embodiment through these steps will be described.
The first step (I) of preparing the polymer precursor comprises:
(I-i) preparing a raw material polymer including a structural unit represented by formula (NB) and a structural unit represented by formula (MA);
(I-ii) a step of reacting the raw material polymer obtained in the 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 including a structural unit represented by formula (NB), a structural unit represented by formula (MA), and a structural unit represented by formula (1);
(I-iii) A step of reacting the first polymer precursor obtained in step (I-iii) 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 formula (NB), a structural unit represented by formula (MA), a structural unit represented by formula (1), and a structural unit represented by formula (2). Here, the second polymer precursor obtained in step (I-iii) 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 formula (NB) and a structural unit represented by formula (MA) can be produced by polymerizing (addition polymerization) a monomer represented by formula (NBm) and maleic anhydride. The definitions of R ¹ , R ² , R ³ , R ⁴ and a ₁ in formula (NBm) are the same as those in formula (NB). The same also applies to preferred aspects.

Examples of monomers represented by the 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 formula (NBm) may be used alone or in combination of two or more.

Although there is no limitation on the polymerization method, radical polymerization using a radical polymerization initiator is preferable. As the polymerization initiator, for example, an azo compound, an organic peroxide, etc. can be used.
Specific examples of the azo compound 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 material polymer is carried out by dissolving the monomer represented by formula (NBm), maleic anhydride and a polymerization initiator in a solvent and charging the resulting solution into a reaction vessel, and then heating the resulting solution to cause addition polymerization. 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.

(Process (I-ii))
The raw polymer obtained in step (I-i) is reacted with a polyfunctional (meth)acrylic compound in the presence of a basic catalyst to form a structure represented by formula (MA) contained in the raw polymer. A part of the units is ring-opened to form the structural unit represented by formula (1), and the structural unit represented by formula (NB), the structural unit represented by formula (MA), and the structural unit represented by formula (1 A first polymer precursor containing a structural unit represented by the formula:

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), or tetrahydrofuran (THF) can be used, but is not limited to these, and various organic solvents used in the synthesis of organic compounds or polymers can be used.

Next, a polyfunctional (meth)acrylic compound is added to the above solution. A basic catalyst is then added. The solution is then mixed appropriately to obtain a homogeneous solution.

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

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

Specific examples of polyfunctional (meth)acrylic compounds represented by 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 formula (MA) contained in the raw polymer and form structural units of formula (1), producing a first polymer precursor containing structural units represented by formula (NB), structural units represented by formula (MA), and structural units represented by formula (1).

(Process (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 to form a monofunctional (meth)acrylic compound contained in the first polymer precursor. A part of the structural unit represented by formula (MA) is ring-opened to form a structural unit represented by formula (2), and the structural unit represented by formula (NB) and the structural unit represented by formula (MA) are A second polymer precursor, ie, a polymer precursor P′, is obtained which contains the structural unit represented by the formula (1) and the structural unit represented by the formula (2).

It is preferable to carry out the step (I-iii) by adding a monofunctional (meth)acrylic compound to the reaction system containing the first polymer precursor obtained in the step (I-ii). In addition, from the viewpoint of steric hindrance of the reaction, the monofunctional (meth)acrylic compound tends to react more easily with the raw material polymer than the polyfunctional (meth)acrylic compound. Therefore, it is preferable to carry out the step (I-ii) of reacting the monofunctional (meth)acrylic compound and the step (I-iii) of reacting the monofunctional (meth)acrylic compound sequentially in this order, rather than simultaneously. In addition, the reaction between the monofunctional (meth)acrylic compound and the first polymer precursor proceeds in the presence of a basic catalyst. As the basic catalyst, the catalyst remaining in the reaction system obtained in the step (I-ii) can be used as it is. Therefore, it is preferable to carry out step (I-iii) in situ by adding a 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, the reaction solution obtained by adding a monofunctional (meth)acrylic compound to the reaction mixture containing the first polymer precursor is heated, preferably at 60 to 80° C. for about 1 to 9 hours, to open a part of the structural unit represented by formula (MA) contained in the first polymer precursor, forming a structural unit represented by formula (2), and generating polymer precursor P'.

The monofunctional (meth)acrylic compound used in the step (I-iii) may, for example, be a compound represented by the following formula (2a-m): In the formula (2a-m), the definitions of ^X10 and R are the same as those in the formula (2a).

Specific examples of compounds represented by 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.

(Step (II))
The polymer precursor P' obtained in step (I-iii) is treated with water in the presence of a catalyst, whereby the structural unit represented by formula (MA) contained in the polymer precursor P' undergoes ring-opening to form a structural unit represented by formula (3), thereby producing a polymer P containing a structural unit represented by formula (NB), a structural unit represented by formula (1), a structural unit represented by formula (2), and a structural unit represented by formula (3). When a part of the structural unit represented by formula (MA) undergoes ring-opening and a part of the structural unit of formula (MA) remains without being ring-opened, the polymer P contains a structural unit represented by formula (MA) in addition to the structural units of formula (NB), formula (1), formula (2), and formula (3).

Step (II) is preferably carried out by adding water to the reaction system containing the polymer precursor P' obtained in step (I-iii). A basic catalyst can be used as the catalyst used in step (II), and the same catalyst as the basic catalyst used in 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 (II), water is added to the reaction system containing the polymer precursor P' obtained in 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 formula (MA) contained in the polymer precursor P' and generate the structural unit represented by formula (3). 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 is. Therefore, it is preferable to carry out step (II) 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.

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

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 the polymer, and 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).
After washing with ion-exchanged water, the polymer powder is dried, for example, at 30 to 60° C. for 16 hours or more, to obtain a high-purity polymer P.

(Photosensitive resin composition)
A photosensitive resin composition can be prepared using the above polymer P and a photoradical polymerization initiator.
As already explained, this photosensitive resin composition has excellent curing properties and therefore good sensitivity, and has high alkali solubility and therefore excellent developability.

The photoradical polymerization initiator that can be used is not particularly limited, and any known initiator can be used appropriately.
For example, 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)methyl]-1-[4-(4-morpholinyl)phenyl ]-1-butanone and other alkylphenone compounds; benzophenone, 4,4'-bis(dimethylamino)benzophenone, 2-carboxybenzophenone and other benzophenone compounds; benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether and other benzoin compounds; thioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone and other thioxanthone compounds; 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-ethoxynaphthyl)- halomethylated triazine compounds such as 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; 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, and 2,2'-bis(2,4-dichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole 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, and 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 photosensitive resin composition may contain only one type of photoradical polymerization initiator, or may contain two or more types of photoradical polymerization initiators.
The amount of the photoradical polymerization initiator used is, for example, 1 to 20 parts by mass, and preferably 3 to 10 parts by mass, based on 100 parts by mass of the polymer P.

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 color filters in liquid crystal displays and solid-state imaging devices. Various pigments or dyes can be used as colorants.

As the pigment, an organic pigment or an inorganic pigment can be used.
Examples of organic pigments that can be used include 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, and dye lake pigments.
Examples of inorganic pigments that can be used include white/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.), lustrous 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) having an appropriate average particle size can be used depending on the purpose and application. In particular, when transparency is required, such as in a color filter, a small average particle size of 0.1 μm or less is preferred, whereas in other cases, such as when hiding properties are required, such as in a paint, a large average particle size of 0.5 μm or more is preferred.
Depending on the purpose and use, the colorant may be subjected to surface treatment such as rosin treatment, surfactant treatment, resin-based dispersant treatment, pigment derivative treatment, oxide film treatment, silica coating, wax coating, etc.

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.

In one embodiment, the photosensitive resin composition may contain a light-shielding agent. By containing a light-shielding agent, the composition can be preferably used as a material for forming a black matrix of a liquid crystal display device or a solid-state image sensor.
As the light-shielding agent, any known light-shielding agent can be used without any particular limitation. For example, black pigments such as carbon black, bone black, graphite, iron black, and titanium black can be used as the light-shielding agent.

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

The photosensitive resin composition typically contains 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. can 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 solvent used is not particularly limited, but is used in an amount that results in a concentration of non-volatile components of, for example, 10 to 70% by mass, preferably 15 to 60% by mass.

In one embodiment, the photosensitive resin composition 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 active 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 crosslinking agents include the following:

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 adduct trimethylolpropane tri(meth)acrylate, ethylene oxide adduct Multifunctional (meth)acrylates such as 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.

(Meth)acrylic acid esters containing vinyl ether groups, 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.

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 of crosslinking agents.
When the photosensitive resin composition contains a crosslinking agent, the amount of the crosslinking agent may be appropriately set according to the purpose and application. For 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 polymer P.

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, surfactants, antistatic agents, dispersants, slip agents, surface modifiers, thixotropic agents, thixotropic aids, silane coupling agents, and polyhydric phenol compounds.

(Patterns, color filters, black matrices, liquid crystal display devices, and solid-state imaging devices)
A film can be formed using the above-mentioned photosensitive resin composition, and the film can be exposed and developed to form a pattern. This pattern is applied to a color filter, a black matrix, 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 having a color filter or a black matrix can be manufactured.

Describe a typical procedure for forming a pattern.

(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, and may be spin coating using a spinner, spray coating using a spray coater, dipping, printing, roll coating, an inkjet method, or the like.

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, preferably 90 to 120°C. The heating time is usually 30 to 600 seconds, 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 the g-line, h-line, or i-line of a mercury lamp, and particularly preferably the i-line. Two or more light beams may be mixed and used. 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 inorganic alkaline solutions such as sodium hydroxide, sodium carbonate, sodium silicate, and ammonia; (ii) aqueous organic amine solutions such as ethylamine, diethylamine, triethylamine, and triethanolamine; and (iii) aqueous solutions of quaternary ammonium salts such as tetramethylammonium hydroxide and tetrabutylammonium hydroxide.
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 0.2 to 5% by mass.

Through the above steps, a pattern can be obtained/a substrate having a pattern can be manufactured, and 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 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 heating process may be performed using a hot plate, an oven, or a temperature-programmable heating oven. The atmospheric gas used during the heating process 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 a substrate 10. A protective film 13 and a transparent electrode layer 14 are provided on 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.
There are usually three colors, red, green, and blue, for the color filter 12. The color filter 12 is made of a cured product of a photosensitive resin composition containing a coloring agent 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 within the scope of the present invention are included in the present invention.

The embodiments of the present invention will be described in detail based on examples and comparative examples. Note that the present invention is not limited to the examples.

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 BHEA: 2-Hydroxyethyl acrylate 4-HBA: 4-Hydroxybutyl acrylate

・A-TMM-3L: A mixture of the following two compounds, the amount of the compound on the left in the mixture based on gas chromatographic measurements is approximately 55% (manufactured by Shin-Nakamura Chemical Co., Ltd.)

・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 chromatographic measurements 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 Material Polymer 1)
588.36 g (6.0 mol) of maleic anhydride, 564.90 g (6.0 mol) of 2-norbornene, and 55.26 g (0.24 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 1716.8 g of methyl ethyl ketone and 188.3 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 dropped into 14,230.2 g of methanol to precipitate a white solid. The obtained white solid was further washed with 3,557.5 g of methanol and then vacuum dried at a temperature of 120° C. to obtain 1,027.2 g of a polymer (raw polymer 1) 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 7,236 and a polydispersity (weight average molecular weight Mw)/(number average molecular weight Mn) of 1.83 as measured by gel permeation chromatography (GPC).

<Synthesis of Polymer P>
Polymer P was prepared using the following method.
(Synthesis Example 1)
Polymer P1 was prepared by ring-opening the MA units of raw material polymer 1 with a trifunctional (meth)acrylic compound and a monofunctional (meth)acrylic compound. The details are described below.
First, 99.01 g of MEK was added to 60 g of raw polymer 1 (0.312 mol in terms of MA) to prepare a solution. Next, 38.75 g of A-TMM-3LM-N was added to this solution, and then 36.00 g (0.356 mol) of triethylamine was added and reacted at a temperature of 70° C. for 2 hours. After that, 45.31 g (0.390 mol) of BHEA 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 solution of formic acid and an aqueous solution of citric acid 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.
The polymer powder after the above-mentioned two washings 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, 61.39 g of 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 BHEA.
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.
Furthermore, ¹³ C-NMR measurement confirmed that polymer P1 had a structure ring-opened with A-TMM-3LM-N and BHEA.
Table 1 also shows the weight average molecular weight (Mw) and polydispersity (Mw/Mn) of polymer P1 measured by GPC.

(Synthesis Example 2)
20.00 g of the polymer P1 obtained in Synthesis Example 1 was dissolved in 46.67 g of PGMEA (propylene glycol monomethyl ether acetate) to prepare a solution. Next, 8.00 g (0.444 mol) of water was added to the solution, and the mixture was reacted at a temperature of 70° C. for 6 hours. The resulting reaction mixture was subjected to solvent substitution to obtain 55.20 g of polymer P2 (solid content concentration: 28.56% by mass).
The above solvent replacement was carried out according to the following procedure.
The obtained reaction mixture was subjected to solvent removal at 50° C. under reduced pressure using a rotary evaporator. When it was confirmed that the polymer solution had become considerably viscous, the operation of removing the solvent was interrupted. Thereafter, 60.00 g of PGMEA was added and mixed until it became uniform. The solvent was removed at 50° C. under reduced pressure in the same manner. When it was confirmed that the polymer solution had become considerably viscous, the operation of removing the solvent was interrupted. Thereafter, 80.00 g of PGMEA was added and mixed until it became uniform. The solvent was removed at 50° C. under reduced pressure in the same manner, and a solution having a solid content concentration of 30% by mass ± 2% by mass was prepared as measured by a heat-drying type moisture meter. The above operations remove the water used in the reaction, and the solvent is replaced with PGMEA.
¹³ C-NMR measurement of polymer P2 confirmed that polymer P2 had a structure ring-opened with A-TMM-3LM-N, BHEA and water.
The weight average molecular weight (Mw) and polydispersity (Mw/Mn) of polymer P2 measured by GPC are shown in Table 1.

(Synthesis Example 3)
A solution was prepared by adding 99.01 g of MEK to 60 g of raw polymer 1 (0.312 mol in terms of MA). Next, 38.75 g of A-TMM-3LM-N was added to this solution, and then 36.00 g (0.356 mol) of triethylamine was added and reacted at a temperature of 70° C. for 2 hours. After that, 45.31 g (0.390 mol) of BHEA was added and reacted at a temperature of 70° C. for 3.5 hours to prepare a reaction solution.
Next, 3.00 g (0.167 mol) of water was added to the resulting reaction solution without post-treatment, and the mixture was reacted at 70° C. for 0.5 hours.
The resulting reaction solution was diluted with MEK and treated with an aqueous solution of formic acid and an aqueous solution of citric acid 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.
The polymer powder after the above-mentioned two washings was washed with an excess amount of water three times.
The resulting reaction product was dried at 40°C for 12 hours.
As a result, 70.52 g of polymer P3 was obtained in which the structural units derived from maleic anhydride in the raw polymer were ring-opened with A-TMM-3LM-N, BHEA and water.
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 P3, which confirmed that the obtained polymer P3 did not contain any unreacted (meth)acrylic compound or any (meth)acrylic compound not having a hydroxyl group.
Furthermore, ¹³ C-NMR measurement confirmed that polymer P3 had a structure ring-opened with A-TMM-3LM-N, BHEA, and water, and ¹³ C-NMR measurement also revealed that polymer P3 had a higher proportion of structures ring-opened with water than polymer P2.
Table 1 also shows the weight average molecular weight (Mw) and polydispersity (Mw/Mn) of polymer P3 measured by GPC.

(Synthesis Example 4)
Polymer P4 was prepared by ring-opening the MA units of raw polymer 1 with a trifunctional (meth)acrylic compound and a monofunctional (meth)acrylic compound. The details are described below.
First, 108.26 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 36.00 g (0.356 mol) of triethylamine was added and reacted at a temperature of 70° C. for 2 hours. After that, 45.31 g (0.390 mol) of BHEA 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 solution of formic acid and an aqueous solution of citric acid 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.
The polymer powder after the above-mentioned two washings 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, 65.76 g of polymer P4 was obtained in which the structural units derived from maleic anhydride in the raw polymer were ring-opened with A-TMM-3LM-N and BHEA.
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 P4, which confirmed that the obtained polymer P4 did not contain any unreacted (meth)acrylic compound or any (meth)acrylic compound not having a hydroxyl group.
Furthermore, ¹³ C-NMR measurement confirmed that polymer P4 had a structure ring-opened with A-TMM-3LM-N and BHEA.
Table 1 also shows the weight average molecular weight (Mw) and polydispersity (Mw/Mn) of polymer P4 measured by GPC.

(Synthesis Example 5)
20.00 g of the polymer P4 obtained in Synthesis Example 1 was dissolved in 46.67 g of PGMEA (propylene glycol monomethyl ether acetate) to prepare a solution. Next, 8.00 g (0.444 mol) of water was added to this solution, and the solution was reacted at a temperature of 70° C. for 6 hours. The resulting reaction mixture was subjected to solvent substitution to obtain 59.35 g of polymer P5 (solid content concentration: 28.70% by mass). The solvent substitution was carried out in the same manner as in Synthesis Example 2.
Furthermore, ¹³ C-NMR measurement confirmed that polymer P5 had a structure ring-opened with A-TMM-3LM-N, BHEA and water.
The weight average molecular weight (Mw) and polydispersity (Mw/Mn) of polymer P5 measured by GPC are shown in Table 1.

(Synthesis Example 6)
A solution was prepared by adding 108.26 g of MEK to 60 g of raw polymer 1 (0.312 mol in terms of MA). Next, 58.12 g of A-TMM-3LM-N was added to this solution, and then 36.00 g (0.356 mol) of triethylamine was added and reacted at a temperature of 70° C. for 2 hours. After that, 45.31 g (0.390 mol) of BHEA was added and reacted at a temperature of 70° C. for 3.5 hours to prepare a reaction solution.
Next, 24.00 g (1.332 mol) of water was added to the resulting reaction solution without post-treatment, and the mixture was reacted at 70° C. for 0.5 hours.
The resulting reaction solution was diluted with MEK and treated with an aqueous solution of formic acid and an aqueous solution of citric acid 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.
The polymer powder after the above-mentioned two washings was washed with an excess amount of water three times.
The resulting reaction product was dried at 40°C for 12 hours.
As a result, 78.50 g of polymer P6 was obtained in which the structural units derived from maleic anhydride in the raw polymer were ring-opened with A-TMM-3LM-N, BHEA and water.
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 P6, which confirmed that the obtained polymer P6 did not contain any unreacted (meth)acrylic compound or any (meth)acrylic compound not having a hydroxyl group.
Furthermore, ¹³ C-NMR measurement confirmed that polymer P6 had a structure ring-opened with A-TMM-3LM-N, BHEA, and water, and ¹³ C-NMR measurement also revealed that polymer P6 had a higher proportion of structures ring-opened with water than polymer P5.
Table 1 also shows the weight average molecular weight (Mw) and polydispersity (Mw/Mn) of polymer P6 measured by GPC.

(Synthesis Example 7)
A solution was prepared by adding 108.26 g of MEK to 60 g of raw polymer 1 (0.312 mol in terms of MA). Next, 58.12 g of A-TMM-3LM-N was added to this solution, and then 36.00 g (0.356 mol) of triethylamine was added and reacted at a temperature of 70° C. for 2 hours. After that, 45.31 g (0.390 mol) of BHEA was added and reacted at a temperature of 70° C. for 3.5 hours to prepare a reaction solution.
Next, 6.00 g (0.333 mol) of water was added to the resulting reaction solution without post-treatment, and the mixture was reacted at 70° C. for 0.5 hours.
The resulting reaction solution was diluted with MEK and treated with an aqueous solution of formic acid and an aqueous solution of citric acid 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.
The polymer powder after the above-mentioned two washings was washed with an excess amount of water three times.
The resulting reaction product was dried at 40°C for 12 hours.
As a result, 70.59 g of polymer P7 was obtained in which the structural units derived from maleic anhydride in the raw polymer were ring-opened with A-TMM-3LM-N, BHEA and water.
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 P7, which confirmed that the obtained polymer P7 did not contain any unreacted (meth)acrylic compound or any (meth)acrylic compound not having a hydroxyl group.
Furthermore, ¹³ C-NMR measurement confirmed that polymer P7 had a structure ring-opened with ^A -TMM-3LM-N, BHEA, and water, and also showed that polymer P7 had a higher proportion of structures ring-opened with water than polymer P5.
The weight average molecular weight (Mw) and polydispersity (Mw/Mn) of polymer P7 measured by GPC are shown in Table 1.

(Synthesis Example 8)
Polymer P8 was prepared by ring-opening the MA units of raw polymer 1 with a trifunctional (meth)acrylic compound and a monofunctional (meth)acrylic compound. The details are described below.
First, 99.71 g of MEK was added to 60 g of raw polymer 1 (0.312 mol in terms of MA) to prepare a solution. Next, 38.75 g of A-TMM-3L 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 solution of formic acid and an aqueous solution of citric acid 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.
The polymer powder after the above-mentioned two washings 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, 58.17 g of polymer P8 was obtained in which the structural units derived from maleic anhydride in the raw polymer were ring-opened with A-TMM-3L 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 P8, 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.
Furthermore, ¹³ C-NMR measurement confirmed that polymer P8 had a structure ring-opened with A-TMM-3L and 4-HBA.
Table 1 also shows the weight average molecular weight (Mw) and polydispersity (Mw/Mn) of polymer P8 measured by GPC.

(Synthesis Example 9)
A solution was prepared by adding 99.71 g of MEK to 60 g of raw polymer 1 (0.312 mol in terms of MA). Next, 38.75 g of A-TMM-3L 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 3.5 hours to prepare a reaction solution.
Next, 9.00 g (0.500 mol) of water was added to the resulting reaction solution without post-treatment, and the mixture was reacted at 70° C. for 0.5 hours.
The resulting reaction solution was diluted with MEK and treated with an aqueous solution of formic acid and an aqueous solution of citric acid 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.
The polymer powder after the above-mentioned two washings was washed with an excess amount of water three times.
The resulting reaction product was dried at 40°C for 12 hours.
As a result, 58.56 g of polymer P9 was obtained in which the structural units derived from maleic anhydride in the raw polymer were ring-opened with A-TMM-3L, 4-HBA and water.
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 P9, and it was confirmed that the obtained polymer P7 did not contain any unreacted (meth)acrylic compound or any (meth)acrylic compound having no hydroxyl group.
Furthermore, ¹³ C-NMR measurement confirmed that polymer P9 had a structure ring-opened with A-TMM-3L, 4-HBA and water.
Table 1 also shows the weight average molecular weight (Mw) and polydispersity (Mw/Mn) of polymer P8 measured by GPC.

(Synthesis Example 10)
Polymer P10 was prepared by ring-opening the MA units of raw material polymer 1 with a trifunctional (meth)acrylic compound and a monofunctional (meth)acrylic compound. The details are described below.
First, 114.39 g of MEK was added to 60 g of raw polymer 1 (0.312 mol in terms of MA) to prepare a solution. Next, 35.03 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. After that, 45.31 g (0.390 mol) of BHEA 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 solution of formic acid and an aqueous solution of citric acid 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.
The polymer powder after the above-mentioned two washings 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, 57.82 g of polymer P10 was obtained in which the structural units derived from maleic anhydride in the raw polymer were ring-opened with A-9550 and BHEA.
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 P10, and it was confirmed that the obtained polymer P7 did not contain any unreacted (meth)acrylic compound or any (meth)acrylic compound having no hydroxyl group.
Furthermore, ¹³ C-NMR measurement confirmed that polymer P10 had a structure ring-opened with A-9550 and BHEA.
Table 1 also shows the weight average molecular weight (Mw) and polydispersity (Mw/Mn) of polymer P10 measured by GPC.

(Synthesis Example 11)
A solution was prepared by adding 102.73 g of MEK to 60 g of raw polymer 1 (0.312 mol in terms of MA). Next, 35.03 g of A-9550 was added to this solution, and then 36.00 g (0.356 mol) of triethylamine was added, and the mixture was reacted at a temperature of 70° C. for 2 hours. After that, 45.31 g (0.390 mol) of BHEA was added, and the mixture was reacted at a temperature of 70° C. for 3.5 hours, and a reaction solution was prepared.
Next, 3.00 g (0.167 mol) of water was added to the resulting reaction solution without post-treatment, and the mixture was reacted at 70° C. for 0.5 hours.
The resulting reaction solution was diluted with MEK and treated with an aqueous solution of formic acid and an aqueous solution of citric acid 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.
The polymer powder after the above-mentioned two washings was washed with an excess amount of water three times.
The resulting reaction product was dried at 40°C for 12 hours.
As a result, 70.77 g of polymer P11 was obtained in which the structural units derived from maleic anhydride in the raw polymer were ring-opened with A-9550, BHEA and water.
It was confirmed by ¹³ C-NMR that polymer P11 had a structure ring-opened with A-9550, BHEA and water.
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 P11. This confirmed that the obtained polymer P7 did not contain any unreacted (meth)acrylic compound or any (meth)acrylic compound not having a hydroxyl group.
Furthermore, ¹³ C-NMR measurement confirmed that polymer P11 had a structure ring-opened with A-9550, BHEA and water.
Table 1 also shows the weight average molecular weight (Mw) and polydispersity (Mw/Mn) of polymer P11 measured by GPC.

(Synthesis Example 12)
A solution was prepared by adding 103.03 g of MEK to 60 g of raw polymer 1 (0.312 mol in terms of MA). Next, 35.03 g of A-9550 was added to this solution, and then 36.00 g (0.356 mol) of triethylamine was added, and the mixture was reacted at a temperature of 70° C. for 2 hours. After that, 45.01 g (0.312 mol) of 4-HBA was added, and the mixture was reacted at a temperature of 70° C. for 3.5 hours, and a reaction solution was prepared.
Next, 6.00 g (0.333 mol) of water was added to the resulting reaction solution without post-treatment, and the mixture was reacted at 70° C. for 0.5 hours.
The resulting reaction solution was diluted with MEK and treated with an aqueous solution of formic acid and an aqueous solution of citric acid 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.
The polymer powder after the above-mentioned two washings was washed with an excess amount of water three times.
The resulting reaction product was dried at 40°C for 12 hours.
As a result, 70.64 g of polymer P12 was obtained in which the structural units derived from maleic anhydride in the raw polymer were ring-opened with A-9550, 4-HBA and water.
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 P12, and it was confirmed that the obtained polymer P7 did not contain any unreacted (meth)acrylic compound or any (meth)acrylic compound having no hydroxyl group.
Furthermore, ¹³ C-NMR measurement confirmed that polymer P12 had a structure ring-opened with A-9550, 4-HBA and water.
Table 1 also shows the weight average molecular weight (Mw) and polydispersity (Mw/Mn) of polymer P12 measured by GPC.

(Synthesis Example 13)
Polymer P13 was prepared by ring-opening the MA units of raw polymer 1 with a trifunctional (meth)acrylic compound and a monofunctional (meth)acrylic compound. The details are described below.
First, 99.71 g of MEK was added to 60 g of raw polymer 1 (0.312 mol in terms of MA) to prepare a solution. Next, 38.75 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 solution of formic acid and an aqueous solution of citric acid 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.
The polymer powder after the above-mentioned two washings 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, 56.44 g of polymer P13 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.
By GPC measurement of polymer P13, it was confirmed that the peaks of the polyfunctional (meth)acrylic compound and the monofunctional (meth)acrylic compound used disappeared. This confirmed that the obtained polymer P7 did not contain any unreacted (meth)acrylic compound or any (meth)acrylic compound without a hydroxyl group. The weight average molecular weight (Mw) and polydispersity (Mw/Mn) of polymer P13 measured by GPC measurement are shown in Table 1.
It was confirmed by ¹³ C-NMR that polymer P13 had the structure A-TMM-3LM-N and ring-opened with 4-HBA.
Furthermore, the amounts (molar fractions, mol %) (A, B, C, and D, respectively) of the structural unit derived from a trifunctional (meth)acrylic compound (A-TMM-3LM-N) (structural unit of formula (1)), the structural unit derived from a monofunctional (meth)acrylic compound (4-HBA) (structural unit of formula (2)), the water ring-opened side chain (structural unit of formula (3)), and the unreacted (unring-opened) MA unit (structural unit of formula (MA)) in polymer P13 were calculated by ¹³ C-NMR integral value analysis. The results are shown below. A ¹³ C-NMR chart is shown in FIG. 2.
As shown in FIG. 2, integral values a, b, c, and d corresponding to each structure were determined as signals present in the chemical shift ranges shown below, and integral values were measured.
a: 164.8-165.3ppm
b: 165.3 to 165.6 ppm
c: 174.7-178.0ppm
d: 168.0 to 174.7 ppm
From the integral values a, b, c, and d, the molar ratios A, B, C, and D were calculated according to the following formula.
A = a / 3
B = b
C={c-(a/3)-b}/2
D={d-(a/3)-b}/2
In addition, since the peaks from 168.0 to 174.7 ppm in the ¹³ C-NMR chart included the peak of citric acid used in the extraction (peak top: 171.30 ppm), the integral value d was calculated by subtracting the integral value from 171.23 to 171.33 ppm (corresponding to citric acid) from the integral value from 168.0 to 174.7 ppm.
The mole fractions of the respective structural units were as follows:
Structural units derived from A-TMM-3LM-N: 13.1 mol%
Structural units derived from 4-HBA: 34.2 mol%
Water-ring-opened side chain: 0.7 mol %
MA units: 52.1 mol%

(Synthesis Example 14)
A solution was prepared by adding 99.71 g of MEK to 60 g of raw polymer 1 (0.312 mol in terms of MA). Next, 38.75 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 3.5 hours to prepare a reaction solution.
Next, 9.00 g (0.500 mol) of water was added to the resulting reaction solution without post-treatment, and the mixture was reacted at 70° C. for 0.5 hours.
The resulting reaction solution was diluted with MEK and treated with an aqueous solution of formic acid and an aqueous solution of citric acid 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.
The polymer powder after the above-mentioned two washings was washed with an excess amount of water three times.
The resulting reaction product was dried at 40°C for 12 hours.
As a result, 65.04 g of polymer P14 was obtained in which the structural units derived from maleic anhydride in the raw polymer were ring-opened with A-TMM-3LM-N, 4-HBA and water.
By GPC measurement of polymer P14, it was confirmed that the peaks of the polyfunctional (meth)acrylic compound and the monofunctional (meth)acrylic compound used disappeared. This confirmed that the obtained polymer P7 did not contain any unreacted (meth)acrylic compound or any (meth)acrylic compound without a hydroxyl group. The weight average molecular weight (Mw) and polydispersity (Mw/Mn) of polymer P13 measured by GPC measurement are shown in Table 1.
It was confirmed by ¹³ C-NMR that polymer P14 had a structure ring-opened with A-TMM-3LM-N, 4-HBA, and water. Furthermore, the amount of each structural unit was calculated in the same manner as in Synthesis Example 13. The results are shown below. The ¹³ C-NMR chart is shown in FIG. 3.
In addition, since the peaks from 168.0 to 174.7 ppm in ^the C-NMR chart included the peaks of citric acid used in the extraction (peak tops: 171.34 ppm and 175.12 ppm), the integral value d was calculated by dividing the integral value from 168.0 to 174.7 ppm by the integral values from 171.33 to 171.39 ppm and 175.08 to 175.15 ppm (both of which correspond to citric acid).
The mole fractions of the respective structural units were as follows:
Structural units derived from A-TMM-3LM-N: 14.0 mol%
Structural units derived from 4-HBA: 35.3 mol%
Water-ring-opened side chain: 7.0 mol %
MA units: 43.6 mol%

The conditions for the ¹³ C-NMR measurement are as follows:
(Test Conditions) The measurement sample was prepared by adding a measurement solvent to a weighed sample to adjust the concentration, and then pouring a specified amount into a sample tube for NMR measurement.
Measurement equipment: JEOL JNM-ECA400 superconducting FT-NMR equipment Resonance frequency: 100.53 MHz
Measurement nucleus: ^13C
Measurement method: NNE measurement (inverse gate decoupling method)
Pulse width: 3.83 μsec
Pulse repetition waiting time: 30 s
Number of measurements: 4096 Measurement temperature: room temperature Measurement solvent: DMSO-d ₆ (deuterated dimethyl sulfoxide)
Sample concentration: 20% (w/v)

Table 1 below shows the components used in each synthesis example and their amounts (converted to maleic anhydride (MA)).

(Examples 1 to 7, Reference Examples 1 to 2, Comparative Examples 1 to 5)
In each of the Examples and Comparative Examples, the alkali solubility of the polymer P obtained in the above synthesis examples was evaluated. Photosensitive resin compositions were prepared using these polymers P, and their performance was evaluated.

<Evaluation>
[Evaluation of Developability] (Dissolution Rate of Polymer P in Alkaline Developer)
Polymers P1, P3, P4, and P6 to P14 obtained in Synthesis Examples 1, 3, 4, and 6 to 14 were dissolved in propylene glycol monomethyl ether acetate (PGMEA) to prepare solutions having a solid content concentration of 30% by mass. Polymers P2 and P5 obtained in Synthesis Examples 2 and 5 were adjusted to have a solid content concentration of 30% by mass ±2% by mass, and were therefore used as they were in the next operation.
Next, the above solution was spin-coated on a wafer, the PGMEA was dried, and the wafer was pre-baked at a temperature of 100° C. for 2 minutes to prepare a resin film having a thickness of 2 μm±0.2 μm.
This resin film was immersed together with the wafer in a 2.0% by mass aqueous solution of sodium carbonate 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 2. If the alkali dissolution rate is 180 nm/s or more, the developability can be considered to be good.

[Sensitivity evaluation (2.0% by mass sodium carbonate aqueous solution)]
First, a photosensitive resin composition was obtained by dissolving the following components in propylene glycol monomethyl ether acetate (PGMEA) so that the total solid content concentration was 30% by mass.
Polymer P (Polymer P obtained in Synthesis Examples 1 to 14): 100 parts by mass (Polymers P2 and P5 were weighed so that the solid content of the polymer excluding PGMEA was 100 parts by mass.)
Polyfunctional acrylate (dipentaerythritol hexaacrylate): 50 parts by mass Photopolymerization initiator (Ingacure OXE01, manufactured by BASF): 5 parts by mass Adhesion aid (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.

The obtained resin composition was 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 about 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 (immersed with the wafer) in a 2.0 mass % aqueous sodium carbonate solution at 23° C. for 60 seconds to obtain thin film B that had been exposed and developed with exposure doses of 1 to 100 mJ/cm ² .
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 regarded as the sensitivity of each photosensitive resin composition and evaluated according to the following criteria. The results are shown in Table 2. The smaller the value of the exposure dose at which the residual film ratio was 95% or more, the higher the sensitivity. If the exposure dose at which the residual film ratio was 95% or more was 40 mJ/cm2 or ^less , the photosensitive material could be used without problems, and in particular, if it was 25 mJ/cm2 or ^less , the sensitivity could be considered to be good.

The results of the alkaline dissolution rate and sensitivity evaluation are shown in Table 2.

Polymer P3, polymer P6, polymer P7, polymer P9, polymer P11, polymer P12 and polymer P14 all have a structural unit (structural unit of formula (3)) in their polymer structure obtained by ring-opening a maleic anhydride structural unit with water, and have a good alkaline dissolution rate and therefore excellent developability. In addition, polymer P3, polymer P7, polymer P9, polymer P11, polymer P12 and polymer P14 have particularly high sensitivity, and therefore photosensitive resin compositions containing these polymers have a good balance between developability and sensitivity.

<Preparation of Color Filter>
A suitable amount of pigment dispersion NX-061 (green, manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.) was further added to the photosensitive resin compositions prepared in Examples 1 to 7 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.
Furthermore, by using NX-053 (blue) or NX-032 (red) manufactured by the same company instead of NX-061 as the pigment dispersion liquid, blue or red color filters could be formed.

<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 7 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 (14)

A polymer comprising a structural unit represented by formula (NB), a structural unit represented by formula (1), a structural unit represented by formula (2), and a structural unit represented by formula (3).

(In formula (NB), 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 a ₁ is 0, 1 or 2.)

(In formula (1), R ^p is a group having two or more (meth)acryloyl groups.)

(In formula (2), ^Rs is a group having one (meth)acryloyl group.)

The polymer of claim 1 further comprising a structural unit represented by the formula (MA):

The polymer according to claim 1 or 2, having an alkaline dissolution rate of 150 nm/s or more. The polymer according to any one of claims 1 to 3, wherein R ^p in the structural unit represented by formula (1) is at least one selected from a group represented by formula (1b), a group represented by formula (1c), and a group represented by formula (1d).

(In formula (1b),
k is 2 or 3;
R is a hydrogen atom or a methyl group, and multiple Rs may be the same or different.
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 formula (1c),
k, R, ^X1 , and ^X2 are the same as R, k, ^X1, and ^X2 in formula (1b), respectively, a plurality of R may be the same or different, and a plurality of ^X1 may be the same or different;
^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 formula (1d),
n is an integer from 2 to 5,
R is a hydrogen atom or a methyl group, and multiple Rs may be the same or different. The polymer according to any one of claims 1 to 4, wherein R ^s in the structural unit represented by formula (2) is a group represented by formula (2a).

In formula (2a), ^X10 is a divalent organic group, and R is a hydrogen atom or a methyl group. A method for producing a polymer containing a structural unit represented by formula (NB), a structural unit represented by formula (1), a structural unit represented by formula (2), and a structural unit represented by formula (3), comprising the steps of:
A first step of preparing a polymer precursor including a structural unit represented by formula (NB), a structural unit represented by formula (1), a structural unit represented by formula (2), and a structural unit represented by formula (MA);
A method for producing a polymer comprising a second step of treating the polymer precursor with water in the presence of a catalyst.

(In formula (NB), 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 a ₁ is 0, 1 or 2.)

(In formula (1), R ^p is a group having two or more (meth)acryloyl groups.)

(In formula (2), ^Rs is a group having one (meth)acryloyl group.)

The method for producing a polymer according to claim 6, wherein the catalyst used in the second step is a basic catalyst. The method for producing a polymer according to claim 6 or 7, wherein the first step and the second step are carried out in situ. The first step comprises:
A step of preparing a raw material polymer containing a structural unit represented by formula (NB) and a structural unit represented by formula (MA);
The method for producing a polymer according to any one of claims 6 to 8, comprising: a step of reacting the raw material polymer with a compound having a hydroxy group and two or more (meth)acryloyl groups in the presence of a basic catalyst to prepare a first polymer precursor comprising a structural unit represented by formula (NB), a structural unit represented by formula (MA), and a structural unit represented by formula (1); and a step of reacting the first polymer precursor with a compound having a hydroxy group and one (meth)acryloyl group in the presence of a basic catalyst to prepare the polymer precursor comprising the structural unit represented by formula (NB), the structural unit represented by formula (1), the structural unit represented by formula (2), and the structural unit represented by formula (MA). The method for producing a polymer according to claim 9, wherein the compound having a hydroxy group and two or more (meth)acryloyl groups is at least one selected from the group consisting of a compound represented by formula (1b-m), a compound represented by formula (1c-m), and a compound represented by formula (1d-m).

(In formula (1b-m),
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 formula (1c-m),
k, R, ^X1 and ^X2 are respectively defined as R, k, ^X1 and ^X2 in formula (1b-m), 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 formula (1d-m),
n is an integer from 2 to 5,
R is a hydrogen atom or a methyl group, and multiple R may be the same or different. The method for producing a polymer according to claim 9 or 10, wherein the compound having a hydroxy group and one (meth)acryloyl group is a compound represented by formula (2a-m):

In formula (2a-m), ^X10 is a divalent organic group, and R is a hydrogen atom or a methyl group. The polymer according to any one of claims 1 to 5, which is used to form a color filter or a black matrix. A polymer according to any one of claims 1 to 5,
A photoradical polymerization initiator,
Photosensitive resin composition. A cured product formed from the photosensitive resin composition according to claim 13.

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