WO2020095774A1

WO2020095774A1 - Copolymer, and resin composition containing copolymer

Info

Publication number: WO2020095774A1
Application number: PCT/JP2019/042472
Authority: WO
Inventors: 優介青木; 恭章川口
Original assignee: 昭和電工株式会社
Priority date: 2018-11-08
Filing date: 2019-10-30
Publication date: 2020-05-14
Also published as: CN113039216B; CN113039216A; KR20210060588A; KR102611643B1; JPWO2020095774A1; JP7347442B2; TW202035481A

Abstract

Provided is an acrylic resin having photosensitivity for realizing photocurability, and having a superior low-refractive index. This copolymer has an acid value of 20 KOHmg/g or more, and is obtained through ring-opening addition performed on an epoxy group of an epoxy group-containing copolymer (P1) by using an unsaturated carboxylic acid (a-4), and adding a polybasic acid anhydride (a-5) to a hydroxyl group generated through ring-opening of the epoxy group. The epoxy group-containing copolymer (P1) contains: at least one structural unit selected from the group consisting of structural units derived from polymerizable monomers (a-1A) having a bridged cyclic hydrocarbon group having 10-20 carbon atoms, and structural units derived from polymerizable monomers (a-1B) represented by chemical formula (1); a structural unit derived from a fluorine-containing (meth)acrylate (a-2) represented by chemical formula (2); and a structural unit derived from an epoxy group-containing (meth)acrylate (a-3).

Description

Copolymer and resin composition containing the copolymer

The present invention relates to a copolymer, a resin composition containing the copolymer, and a resist.
The present application claims priority based on Japanese Patent Application No. 2018-210789 filed in Japan on November 8, 2018, and the content thereof is incorporated herein.

In recent years, from the viewpoint of resource saving and energy saving, photosensitive resin compositions curable by active energy rays such as ultraviolet rays and electron rays have been widely used in the fields of various coatings, printing, paints, adhesives and the like. Also in the field of electronic materials such as printed wiring boards, photosensitive resin compositions curable by active energy rays can be used as solder resists, color filters, black matrices, black column spacers, photo spacers, protective film resists, etc. It is used. Furthermore, the required properties for curable photosensitive resin compositions are becoming more diverse and sophisticated. These required properties include, for example, short-time curability in consideration of productivity, low-temperature curability that suppresses thermal damage to applied members, and the like.

Above all, the low reflectivity of electronic material members is emphasized in order to enhance the functionality of various devices. Therefore, in recent years, the development of members with the theme of low reflectivity has been earnestly studied. For example, in microlenses used in digital cameras, smartphones, etc., there is an increasing demand for coating a low reflectance layer along the surface of the microlens. By coating the low-reflectance layer, the reflected light from the concave portions between the lenses can be significantly suppressed, the S / N ratio can be improved, and a high-quality image with little noise can be realized.
In an image display device such as a liquid crystal display or an organic EL display, when external light such as sunlight or a fluorescent lamp is reflected, the external light diffuses after reaching the inside of the substrate of the image display device. As a result, the visibility of the screen is reduced. Therefore, for the purpose of improving visibility, there is an increasing demand for a low-reflection display in which various members constituting the image display device substrate are made to have a low reflectance to minimize the reflection of external light. Examples of these members include a transparent substrate, a color filter, a black matrix, a column spacer, and a protective film.

In order to meet these demands, it is required to reduce the reflectance of a photosensitive resin composition used as a resist for coating the surface of a microlens, and to manufacture a member constituting an image display device substrate. There is a demand for lowering the reflectance of the photosensitive resin composition used as a resist. That is, it is required to reduce the reflectance of the resin itself that constitutes these photosensitive resin compositions.

As shown by the Fresnel equation, there is a positive correlation between the reflectance and the refractive index. Therefore, it is effective to introduce into the resin an atomic group exhibiting a low refractive index as a method for achieving a low reflectance of the resin constituting the photosensitive resin composition. One of the most effective methods is to introduce a fluorine atom. Above all, an acrylic resin obtained by polymerizing a fluorine-containing (meth) acrylate is particularly noted as a fluorine atom-introduced resin that can be provided simply and efficiently. However, the fluorine atom-introduced resin has poor solubility and poor affinity with other photosensitive resin compositions. Therefore, when a composition containing the resin is applied to a substrate, it becomes a ball on the substrate. As a result, there often occurs a problem that the cured film cannot be formed smoothly.

Therefore, as shown in Patent Documents 1 and 2, by introducing a fluorine atom introducing another monomer group and a fluorine-containing (meth) acrylate, the solubility is improved and smooth coatability of the cured film is realized. A resin can be provided.

On the other hand, strict dimensional accuracy is required to manufacture a coating on the surface of a microlens or a member constituting an image display device substrate. When forming these members, a photolithography method is widely used in which the photosensitive resin composition is applied, exposed, developed, and baked, and the members are pinpointed without any defects such as pinholes at required portions. It is used.
Generally, the photolithography method includes exposure with active energy rays such as ultraviolet rays and electron beams, and a developing step with an alkali developing solution. The photosensitive resin composition used in this method is required to have sensitivity to active energy rays and alkali developability. Therefore, in the photosensitive resin composition used in this method, an alkali-soluble resin is used as the binder of the coating film forming the member. In addition, a reactive diluent, a photopolymerization initiator, and if necessary, an additive such as a colorant are included.

To improve the sensitivity of the alkali-soluble resin, it is necessary to introduce a functional group that causes a reaction during exposure to active energy rays. As such a functional group, an ethylenically unsaturated group is generally mentioned. On the other hand, in order to improve the alkali developability, the method of introducing an acid group is the most general. Examples of the acid group include a carboxy group, a phosphoric acid group and a sulfonic acid group. When a black matrix, a color filter (a colored pattern of each pixel of R / G / B), a protective film, and the like are repeatedly formed like an image display device substrate, an alkali-soluble resin as a binder of a coating film is used. , High degradability, high heat yellowing, high solvent resistance, etc. are required.

JP, 2007-119572, A JP, 2013-6928, A

However, the conventional resin has a low degree of fluorine substitution in the fluorine-containing (meth) acrylate and a low composition ratio of the fluorine-containing (meth) acrylate in all the monomers, so that it is possible to provide a satisfactory low refractive index acrylic resin. Is insufficient. Further, the conventional resin is not a photosensitive resin that can be cured by active energy rays such as ultraviolet rays and electron beams, but exhibits photocurability by blending with other photosensitive resins and additives. For the purpose of improving productivity, a photosensitive resin composition that exhibits photocurability with a single liquid is in high demand, but a photosensitive acrylic resin having a satisfactory low refractive index has not been provided yet. Furthermore, fluorine-containing acrylic resins, including conventional resins, generally have poor affinity with alkali developers, and further improvement in alkali developability is necessary to satisfy the strict dimensional accuracy of the members. is there.
The present invention has been made in order to solve the above problems, and provides an acrylic resin having an excellent low refractive index in one liquid while exhibiting both photocurability and alkali developability, and the resin Accordingly, it is an object of the present invention to provide a photosensitive resin composition used for a resist that contributes to low reflection and high definition of all electronic material members such as microlenses and image display devices.

That is, the present invention is shown in the following [1] to [11].

[1] The unsaturated carboxylic acid (a-4) is ring-opened and added to the epoxy group of the epoxy group-containing copolymer (P1), and the hydroxy group formed by ring opening of the epoxy group is polybasic acid. A copolymer (A1) obtained by adding an anhydride (a-5),
The epoxy group-containing copolymer (P1) is
Consisting of a structural unit derived from a polymerizable monomer (a-1A) having a bridged cyclic hydrocarbon group having 10 to 20 carbon atoms and a structural unit derived from a polymerizable monomer (a-1B) represented by the following chemical formula (1) At least one selected from the group;
A structural unit derived from a fluorine-containing (meth) acrylate (a-2) represented by the following chemical formula (2),
A copolymer containing a structural unit derived from an epoxy group-containing (meth) acrylate (a-3),
A copolymer having an acid value of 20 KOHmg / g or more.

(X and X ′ in the formula (1) each independently represent a hydrogen atom, a linear or branched hydrocarbon group having 1 to 4 carbon atoms, and R 1 and R 2 each independently. A hydrogen atom, a carboxy group, or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and may have a cyclic structure connecting R1 and R2.)

(In the formula (2), R3 represents a hydrogen atom or a methyl group, L represents —O—, —O—CH ₂ —CH (OH) —CH ₂ —, —O—NH—C (═O) —CH. ₂ --CH _2-, each Z independently represents a hydrogen atom, a fluorine atom, a CF ₃ group, a C ₂ F ₅ group, a C ₃ F ₇ group or a hydroxy group, and n is 0 to It is an integer of 12. However, at least three fluorine atoms are included in the formula (2).
[2] Unsaturated group-containing copolymer (A2-) having a hydroxy group formed by ring-opening addition of the carboxyl group-containing copolymer (P2) to the epoxy group of the epoxy group-containing (meth) acrylate (a-3) I), and the unsaturated group-containing copolymer (A2) obtained by adding the polybasic acid anhydride (a-5) to the hydroxy group of the unsaturated group-containing copolymer (A2-I) having the hydroxy group. -II) a copolymer (A2) containing at least one selected from the group consisting of
The carboxy group-containing copolymer (P2) is
Consisting of a structural unit derived from a polymerizable monomer (a-1A) having a bridged cyclic hydrocarbon group having 10 to 20 carbon atoms and a structural unit derived from a polymerizable monomer (a-1B) represented by the following chemical formula (1) At least one selected from the group;
A structural unit derived from a fluorine-containing (meth) acrylate (a-2) represented by the following chemical formula (2),
A copolymer containing a structural unit derived from an unsaturated carboxylic acid (a-4),
A copolymer having an acid value of 20 KOHmg / g or more.

(In the formula (2), R3 represents a hydrogen atom or a methyl group, L represents —O—, —O—CH ₂ —CH (OH) —CH ₂ —, —O—NH—C (═O) —CH. ₂ --CH _2-, each Z independently represents a hydrogen atom, a fluorine atom, a CF ₃ group, a C ₂ F ₅ group, a C ₃ F ₇ group or a hydroxy group, and n is 0 to It is an integer of 12. However, at least three fluorine atoms are included in the formula (2).
[3] The copolymer according to [1] or [2], which has a refractive index of less than 1.50.
[4] The copolymer according to [1] or [3], wherein the epoxy group-containing copolymer (P1) has a fluorine equivalent of 100 g / mol or less.
[5] The copolymer according to [2] or [3], wherein the carboxy group-containing copolymer (P2) has a fluorine equivalent of 100 g / mol or less.
[6] The polymerizable monomer (a-1A) having a bridged cyclic hydrocarbon group having 10 to 20 carbon atoms is dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, isobornyl (meth) acrylate. And the copolymer according to any one of [1] to [5], containing at least one selected from the group consisting of, and adamantyl (meth) acrylate.
[7] A resin composition containing the copolymer according to any one of [1] to [6] and a solvent (B).
[8] The resin composition according to [7], which further contains a reactive diluent (C).
[9] The resin composition according to [7] or [8], which further contains a photopolymerization initiator (D).
[10] contains a colorant (E),
The resin composition according to any one of [7] to [9], wherein the colorant (E) is at least one selected from the group consisting of dyes and pigments.
[11] A resist comprising a cured product of the resin composition according to [9] or [10].

According to the present invention, it is possible to provide an acrylate-based copolymer having an excellent low refractive index while exhibiting photocurability. In addition, the resin composition of the present invention can be suitably used for a resist that contributes to low reflection and high definition of all electronic material members such as microlenses and image display devices.

The present invention will be described in detail below.

[Copolymer (A)]
[First embodiment]
The first embodiment of the copolymer (A) of the present invention is such that the unsaturated carboxylic acid (a-4) is ring-opened and added to the epoxy group of the epoxy group-containing copolymer (P1). Is a copolymer (A1) obtained by adding a polybasic acid anhydride (a-5) to the hydroxy group generated by ring opening, and is characterized by having an acid value of 20 KOHmg / g or more. The epoxy group-containing copolymer (P1) is a structural unit derived from a polymerizable monomer (a-1A) having a bridged cyclic hydrocarbon group having 10 to 20 carbon atoms and a polymerizable unit represented by the above chemical formula (1). At least one selected from the group consisting of structural units derived from the monomer (a-1B), a structural unit derived from the fluorine-containing (meth) acrylate (a-2) represented by the chemical formula (2), and an epoxy group-containing It is a copolymer containing a structural unit derived from (meth) acrylate (a-3). The epoxy group-containing copolymer (P1) preferably further contains a constituent unit derived from a hydroxy group-containing (meth) acrylate (a-6). Here, the (meth) acrylate means one or more selected from methacrylate and acrylate.

[Epoxy group-containing copolymer (P1)]
The epoxy group-containing copolymer (P1) relating to the copolymer (A1) of the present embodiment (hereinafter sometimes simply referred to as “copolymer (P1)”) is a crosslinker having 10 to 20 carbon atoms. At least one selected from the group consisting of a polymerizable monomer (a-1A) having a cyclic hydrocarbon group and a polymerizable monomer (a-1B) represented by the following chemical formula (1) and the following chemical formula (2) It is a copolymer of the monomer (M1) containing the indicated fluorine-containing (meth) acrylate (a-2) and the epoxy group-containing (meth) acrylate (a-3). The fluorine equivalent of the epoxy group-containing copolymer (P1) is preferably 100 g / mol or less, more preferably 30 to 100 g / mol, and further preferably 40 to 100 g / mol.
The monomer (M1) of the copolymer (P1) of the present embodiment preferably further contains a hydroxy group-containing (meth) acrylate (a-6). When the hydroxy group-containing (meth) acrylate (a-6) is copolymerized, alkali developability can be further enhanced.
The above-mentioned monomer (M1) of the copolymer (P1) of the present embodiment is other than the above-mentioned monomers (a-1A), (a-1B), (a-2), (a-3) and (a-6). Other polymerizable monomer (a-7) may be included.

[Polymerizable Monomer (a-1A)]
The polymerizable monomer (a-1A) (hereinafter sometimes simply referred to as “monomer (a-1A)”) has a bridged cyclic hydrocarbon group having 10 to 20 carbon atoms. Here, the bridged cyclic hydrocarbon means one having a structure represented by the following formula (3) or (4) represented by adamantane and norbornane, and the bridged cyclic hydrocarbon group is , Refers to a group corresponding to the rest of the structure except for some hydrogen. Further, the polymerizable monomer (a-1A) does not include the later-described polymerizable monomer (a-1B).

(In the formula (3), A and B each represent a linear or branched alkylene group (including cyclic group), R4 represents a hydrogen atom or a methyl group. A and B may be the same or different. , Or the branches of A and B may be connected to form a ring.)

(In formula (4), A ', B', and D each represent a linear or branched alkylene group (including cyclic group), and R5 represents a hydrogen atom or a methyl group. A ', B', and D. May be the same or different, and the branches of A ′, B ′, and D may be connected to form a ring.)

The monomer (a-1A) is preferably a (meth) acrylate having a bridged cyclic hydrocarbon group having 10 to 20 carbon atoms, and has an adamantyl (meth) acrylate or a structure represented by the following formula (5) ( More preferred is (meth) acrylate. ‥

(In formula (5), R6 to R8 each represent a hydrogen atom or a methyl group. R9 and R10 may be a hydrogen atom or a methyl group, or may be bonded to each other to form a saturated or unsaturated ring. The ring is preferably a 5-membered ring or a 6-membered ring. * Represents a bond linked to the (meth) acrylate group.)

Examples of the monomer (a-1A) include dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, isobornyl (meth) acrylate and adamantyl (meth) acrylate. These may be used alone or in combination of two or more.

[Polymerizable Monomer (a-1B)]
The polymerizable monomer (a-1B) (hereinafter sometimes simply referred to as “monomer (a-1B)”) is a monomer represented by the following general formula (1).

The monomer (a-1B) is not particularly limited as long as it has the chemical structure represented by the general formula (1). In the general formula (1), examples of X and X'representing a linear or branched hydrocarbon group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and an n-butyl group. Group, isobutyl group, t-butyl group and the like. In addition, examples of the substituent of the hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, which is represented by R1 and R2, include an alkoxy group and an aryl group. Examples of R1 and R2 are methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, t-amyl group, stearyl group, lauryl group, 2-ethylhexyl group. A linear or branched alkyl group such as; cyclohexyl group, t-butylcyclohexyl group, dicyclopentadienyl group, tricyclodecanyl group, isobornyl group, adamantyl group, 2-methyl-2-adamantyl group, etc. Examples thereof include a cyclic group; an alkyl group substituted with an alkoxy group such as a 1-methoxyethyl group and a 1-ethoxyethyl group; an alkyl group substituted with an aryl group such as a phenylaralkyl group.

Examples of the monomer (a-1B) having the chemical structure represented by the general formula (1) include norbornene, norbornene (bicyclo [2.2.1] hept-2-ene), and 5-methylbicyclo [2.2]. .1] hept-2-ene, 5-ethylbicyclo [2.2.1] hept-2-ene, tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-methyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-ethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodeca-3-ene, dicyclopentadiene, tricyclo [5.2.1.0 ^2,6 ] deca-8-ene, tricyclo [5.2.1.0 ^2,6 ] deca-3 -Ene, tricyclo [4.4.0.1 ^2,5 ] undec-3-ene, tricyclo [6.2.1.0 ^1,8 ] undec-9-ene, tricyclo [6.2.1.0] ^1,8 ] undec-4-ene, tetracyclo [4.4.0.1 ^2,5 . 1 ^{7, 10} . 0 ^1,6 ] dodec-3-ene, 8-methyltetracyclo [4.4.0.1 ^2,5 . 1 ^{7, 10} . 0 ^1,6 ] dodec-3-ene, 8-ethylidenetetracyclo [4.4.0.1 ^2,5 . 1 ^7,12 ] Dodeca-3-ene, 8-ethylidenetetracyclo [4.4.0.1 ^2,5 . 1 ^{7, 10} . 0 ^1,6 ] dodec-3-ene, pentacyclo [6.5.1.1 ^3,6 . 0 ^2,7 . 0 ^9,13] pentadeca-4-ene, pentacyclo [7.4.0.1 ^2,5. 1 ^{9 and 12} . 0 ^8,13] pentadeca-3-ene, and the like. These may be used alone or in combination of two or more.

Use of the monomer (a-1A) and / or the monomer (a-1B) contributes to smooth coatability of the cured film, high thermal decomposition resistance, and high heat yellowing. Further, it is possible to suppress the decrease in the solubility of the copolymer in the solvent due to the presence of fluorine. One of the monomer (a-1A) and the monomer (a-1B) may be used, or both of them may be used.
Among them, it is preferable to use one or more selected from adamantyl (meth) acrylate, a (meth) acrylate having a structure represented by the above formula (5), and norbornene. Dicyclopentenyl (meth) acrylate, dicyclopenta It is more preferable to use one or more selected from nyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate and norbornene.

[Fluorine-containing (meth) acrylate (a-2)]
The fluorine-containing (meth) acrylate (a-2) (hereinafter sometimes simply referred to as “monomer (a-2)”) is a fluorine-containing (meth) acrylate represented by the following chemical formula (2).

(In the formula (2), R3 represents a hydrogen atom or a methyl group, L represents —O—, —O—CH ₂ —CH (OH) —CH ₂ —, —O—NH—C (═O) —CH. ₂ --CH _2-, each Z independently represents a hydrogen atom, a fluorine atom, a CF ₃ group, a C ₂ F ₅ group, a C ₃ F ₇ group or a hydroxy group, and n is 0 to It is an integer of 12. However, at least three fluorine atoms are included in the formula (2).

The fluorine-containing (meth) acrylate (a-2) is not particularly limited as long as it is represented by the above formula (2). The use of the fluorine-containing (meth) acrylate (a-2) makes it possible to lower the refractive index of the resin, but the effect becomes remarkable when the monomer contains three or more fluorine atoms. When n ≧ 13, further lowering of the refractive index can be expected, but there is a risk that the hardness of the cured film may not be sufficiently exhibited, so that n is in the range of 0 to 12.

As the fluorine-containing (meth) acrylate (a-2), a commercially available product may be used, or a reactive (meth) acrylic acid such as (meth) acrylic acid, glycidyl (meth) acrylate, or 2-isocyanatoethyl (meth) acrylate may be used. ) Acrylic acid derivative and fluoroalcohol may be self-condensed and prepared. Specific examples include 2,2,2-trifluoroethyl (meth) acrylate, 3,3,3-trifluoropropyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate and 3 , 3,4,4-Tetrafluorobutyl (meth) acrylate, 2,2,3,3,3-pentafluoropropyl (meth) acrylate, 3,3,4,4,4-pentafluorobutyl (meth) acrylate 1H, 1H-perfluoro-n-butyl (meth) acrylate, 1H, 1H-perfluoro-n-pentyl (meth) acrylate, 1H, 1H-perfluoro-n-hexyl (meth) acrylate, 1H, 1H-perfluoro-n -Octyl (meth) acrylate, 1H, 1H-perfluoro-n-decyl (meth) acrylate, 1H 1H-perfluoro-n-dodecyl (meth) acrylate, 1H, 1H-perfluoroisobutyl (meth) acrylate, 1H, 1H-perfluoroisooctyl (meth) acrylate, 1H, 1H-perfluoroisododecyl (meth) acrylate, 1H, 1H , 5H-octafluoropentyl (meth) acrylate, 1H, 1H, 5H-perfluoropentyl (meth) acrylate, 1H, 1H, 6H-perfluorohexyl (meth) acrylate, 1H, 1H, 7H-perfluoroheptyl (meth) acrylate, 1H, 1H, 8H-perfluorooctyl (meth) acrylate, 1H, 1H, 9H-perfluorononyl (meth) acrylate, 1H, 1H, 10H-perfluorodecyl (meth) acrylate, 1H, 1H, 11H Perfluoroundecyl (meth) acrylate, 1H, 1H, 12H-perfluorododecyl (meth) acrylate, 2- (perfluoro-n-propyl) ethyl (meth) acrylate, 2- (perfluoro-n-butyl) ethyl (meth) acrylate , 2- (perfluoro-n-hexyl) ethyl (meth) acrylate, 2- (perfluoro-n-octyl) ethyl (meth) acrylate, 2- (perfluoro-n-decyl) ethyl (meth) acrylate, 2- (perfluoro Isobutyl) ethyl (meth) acrylate, 2- (perfluoroisooctyl) ethyl (meth) acrylate, 1H, 1H, 2H, 2H-nonafluorohexyl (meth) acrylate, 1H, 1H, 2H, 2H-tridecafluorooctyl ( (Meth) acrylate, 1H, 1H, 2H, 2H-heptadecafluorodecyl (meth) acrylate and the like can be mentioned. These may be used alone or in combination of two or more.
Of these, fluoroalkyl (meth) acrylates (a-2) having 3 to 20 fluorine atoms are preferable from the viewpoint of easy production of the copolymer (P1).

[Epoxy group-containing (meth) acrylate (a-3)]
The epoxy group-containing (meth) acrylate (a-3) (hereinafter sometimes simply referred to as “monomer (a-3)”) is not particularly limited as long as it is a monomer having an epoxy group and an ethylenically unsaturated group. Not done. Specific examples include glycidyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate glycidyl ether, and 3,4-epoxycyclohexylmethyl (meth) acrylate. In particular, glycidyl (meth) acrylate is preferable from the viewpoint of easy availability and good reactivity.

The constitutional unit derived from the epoxy group-containing (meth) acrylate (a-3) and the unsaturated carboxylic acid (a-4) described later impart a photosensitive group that exhibits photocurability, and therefore, are included in one embodiment of the present invention. It is an essential constituent in the copolymer (A). By introducing a photosensitive group exhibiting photocurability, the cured film exhibits sufficient hardness and high solvent resistance. Further, it is possible to suppress the decrease in solubility of the copolymer in the solvent due to the presence of fluorine, a photosensitive resin composition obtained by mixing a fluororesin having no photocurability and another photocurable component In comparison, a photosensitive resin composition having a good affinity can be provided.
The (meth) acrylate having a hydroxy group, a carboxy group, and an epoxy group is a monomer (a-3).

[Hydroxy group-containing (meth) acrylate (a-6)]
The hydroxy group-containing (meth) acrylate (a-6) is not particularly limited as long as it is a (meth) acrylate containing one or more hydroxy groups. Specific examples include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3-hydroxypentyl (meth) acrylate, 4-hydroxypentyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate, 4-hydroxyhexyl (meth) acrylate, 5-hydroxyhexyl (meth) acrylate, 6-hydroxyhexyl ( (Meth) acrylate, 5-hydroxy-3-methyl-pentyl (meth) acrylate, cyclohexane-1,4-dimethanol-mono (meth) acrylate, 2- (2-hydroxyethyloxy) ethyl (meth) a Relate, 2,3-dihydroxy (meth) acrylate, butane triol mono (meth) acrylate, pentane triol mono (meth) acrylate.
The (meth) acrylate having a hydroxy group and a carboxy group is a monomer (a-6).

[Other polymerizable monomers (a-7)]
The epoxy group-containing copolymer (P1) relating to the copolymer (A) according to one aspect of the present invention includes the monomer (a-1A), the monomer (a-1B), the monomer (a-2), and Copolymerization of the monomer (a-3) and other polymerizable monomer (a-7) other than the above-mentioned monomer (a-6) (hereinafter sometimes simply referred to as “monomer (a-7)”). It may be done.
The other polymerizable monomer (a-7) is a copolymerizable monomer other than the above-mentioned monomers (a-1A), (a-1B), (a-2) and (a-3). This monomer (a-7) is generally a radically polymerizable compound having an ethylenically unsaturated group, and specific examples thereof include dienes such as butadiene; methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl. (Meth) acrylate, iso-propyl (meth) acrylate, n-butyl (meth) acrylate, sec-butyl (meth) acrylate, iso-butyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) ) Acrylate, neopentyl (meth) acrylate, benzyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, dodecyl (meth) acrylate, cyclopentyl (Meth) acrylate, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, ethylcyclohexyl (meth) acrylate, rosin (meth) acrylate, allyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, triphenylmethyl (meth) (Meth) acrylic acid esters such as acrylate, cumyl (meth) acrylate, 3- (N, N-dimethylamino) propyl (meth) acrylate, naphthalene (meth) acrylate, anthracene (meth) acrylate; (meth) acrylic acid Amide, (meth) acrylic acid N, N-dimethylamide, (meth) acrylic acid N, N-diethylamide, (meth) acrylic acid N, N-dipropylamide, (meth) acrylic acid N, N-di-iso -Propyl Amide, (meth) acrylic acid amide such as (meth) acrylic acid anthracenylamide; (meth) acrylic acid anilide, (meth) acryloylnitrile, acrolein, vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, N -Vinyl compounds such as vinylpyrrolidone, vinylpyridine, vinyl acetate and vinyltoluene; styrene, α-alkyl, o-alkyl, m-alkyl, p-alkyl, nitro, cyano, amide derivatives of styrene; N-phenylmaleimide, N -Maleimides such as -cyclohexylmaleimide, N-laurylmaleimide and N- (4-hydroxyphenyl) maleimide; unsaturated dicarboxylic acid diesters such as diethyl citraconic acid, diethyl maleate, diethyl fumarate, diethyl itaconic acid and the like. These may be used alone or in combination of two or more, if necessary.

[Ratio of structures derived from each monomer of the epoxy group-containing copolymer (P1)]
In the copolymer (P1) according to the present invention, the ratio of the structure derived from each monomer is the value of the molar ratio of each polymerizable monomer added for the copolymerization reaction. The mixing ratio (molar ratio) of each monomer is not particularly limited, but when the total amount of the monomers (M1) constituting the epoxy group-containing copolymer (P1) is 100 mol%, the monomer (a-1A) and The total blending ratio of the monomer (a-1B) is preferably 1 to 40 mol%, more preferably 2 to 20 mol%. When the mixing ratio of the monomer (a-1A) and the monomer (a-1B) is 1 mol% or more, desired thermal decomposition resistance, thermal yellowing resistance, and good solubility in a solvent can be obtained. On the other hand, when the blending ratio is 40 mol% or less, the blending ratio of the monomer (a-2) and the monomer (a-3) becomes sufficiently large, and the copolymer (A) having a desired refractive index and curability. Is obtained. The mixing ratio of the monomer (a-2) is preferably 20 to 90 mol%, more preferably 30 to 85 mol%. When the blending ratio of the monomer (a-2) is 20 mol% or more, the copolymer (A) having a sufficiently low refractive index can be obtained. If the blending ratio of the monomer (a-2) is 90 mol% or less, the blending ratio of the monomer (a-1A) and / or the monomer (a-1B) and the monomer (a-3) will be sufficiently high, and the desired amount will be obtained. A copolymer (A) having thermal decomposition resistance, curability, and good solubility in a solvent can be obtained. The mixing ratio of the monomer (a-3) is preferably 9 to 70 mol%, more preferably 13 to 65 mol%. When the blending ratio of the monomer (a-3) is 9 mol% or more, sufficient curability can be exhibited when the photosensitive resin composition is formed, and the fluororesin and other photocurable resin having no photocurability can be used. It is possible to provide a photosensitive resin composition having good affinity as compared with a photosensitive resin composition in which a photocurable component is mixed. If the blending ratio of the monomer (a-3) is 70 mol% or less, the blending ratio of the monomer (a-1A) and / or the monomer (a-1B) and the monomer (a-2) will be sufficiently high, and the desired amount will be obtained. A copolymer (A) having thermal decomposition resistance and refractive index can be obtained. The blending ratio of the monomer (a-6) is preferably 0 to 50%, more preferably 0 to 20%.

[Copolymerization reaction (method for producing epoxy group-containing copolymer (P1)]]
The epoxy group-containing copolymer (P) according to the present invention can be produced by using a copolymerization reaction. The copolymerization reaction carried out in the present invention can be carried out according to a radical polymerization method known in the art. For example, a monomer used for copolymerization may be dissolved in a solvent, a polymerization initiator may be added to the solution, and the reaction may be performed at 50 to 130 ° C. for 1 to 20 hours. Alternatively, the monomer used for the copolymerization and the polymerization initiator may be added dropwise to the solvent adjusted to 50 to 130 ° C. for the reaction.

The solvent that can be used in this copolymerization reaction is not particularly limited as long as it is inert to radical polymerization, and a commonly used organic solvent can be used. Specific examples include glycol ether solvents such as propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate; aromatic solvents such as toluene and xylene; ester solvents such as ethyl acetate, isopropyl acetate and ethyl lactate. These may be used alone or in combination of two or more. Of these, glycol ether solvents are preferred.

The amount of the solvent used in the copolymerization reaction is not particularly limited, but is generally 30 to 1000 parts by mass, preferably 50 to 800 parts by mass, when the total amount of the monomers used in the copolymerization is 100 parts by mass. In particular, when the amount of the solvent used is 1000 parts by mass or less, the decrease in the molecular weight of the copolymer (P) due to the chain transfer action is suppressed, and the viscosity of the copolymer (P) is controlled within an appropriate range. be able to. Further, by using the solvent in an amount of 30 parts by mass or more, an abnormal polymerization reaction can be prevented, the polymerization reaction can be stably performed, and coloring and gelation of the copolymer (P) can be prevented. You can also

The polymerization initiator that can be used in this copolymerization reaction is not particularly limited as long as it can initiate radical polymerization, and a commonly used organic peroxide catalyst or azo compound can be used. You can Specifically, azobisisobutyronitrile, azobisisovaleronitrile, 2,2'-azobis (2,4-dimethylvaleronitrile), azobis (2-methylpropionic acid) dimethyl, benzoyl peroxide, dicumyl Peroxide, diisopropyl peroxide, di-t-butyl peroxide, t-butyl peroxybenzoate, t-hexyl peroxybenzoate, t-butyl peroxy-2-ethylhexanoate, t-hexyl peroxy-2- Examples thereof include ethylhexanoate and 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate.
These may be used alone or in combination of two or more, and it is desirable to select a radical polymerization initiator having an appropriate half-life according to the polymerization temperature.

The amount of the polymerization initiator used in this copolymerization reaction is not particularly limited, but is generally 0.5 to 20 parts by mass, preferably 1.0 to 10 parts by mass when the total amount of the monomers used in the copolymerization is 100 parts by mass. 10 parts by mass.

The fluorine equivalent of the epoxy group-containing copolymer (P1) is the mass of the polymer per the number of moles of fluorine atom, and is a calculated value calculated based on the amount of the monomer used. If this value is 100 g / mol or less, the refractive index of the acrylic resin as an acrylic resin that exhibits photocurability by adding an unsaturated carboxylic acid (a-4) or an ethylenically unsaturated group-containing reactive monomer (b-2) It is possible to obtain the copolymer (A) of the present invention having a sufficiently low value. The lower this value is, the lower the refractive index of the copolymer (A) can be, but the solubility of the copolymer in a solvent is lowered, and the affinity with other photosensitive resin compositions is deteriorated. There is a fear. Therefore, the fluorine equivalent is preferably 30 to 100 g / mol, more preferably 40 to 100 g / mol.

[Unsaturated group-containing copolymer (A1)]
The unsaturated group-containing copolymer (A1) is obtained by ring-opening addition of the unsaturated carboxylic acid (a-4) to the epoxy group of the epoxy group-containing copolymer (P1), and further by opening the epoxy group. The polybasic acid anhydride (a-5) is added to the resulting hydroxy group and the hydroxy group of the monomer (a-6).

The copolymer (A1) of the present embodiment is excellent in photosensitivity because it contains the structural unit derived from the addition reaction in which the unsaturated carboxylic acid (a-4) and the polybasic acid anhydride (a-5) participate. At the same time when the double bond is introduced, a hydroxy group having excellent alkali developability can be obtained by ring opening of the epoxy group. Further, by adding a polybasic acid anhydride to the obtained hydroxy group, a carboxy group can be introduced to enhance the alkali developability. With this structural unit, sufficient hardness of the cured product is exhibited, and high solvent resistance is exhibited. Further, by introducing an acidic group or a hydroxy group as an alkali developing group, the affinity of the copolymer with an alkali developing solution is increased, and a highly precise curing pattern can be formed, and strict dimensional accuracy is realized. To do.
Further, the curability due to heat can be simultaneously exhibited by leaving the whole amount of the epoxy group without reacting with the unsaturated carboxylic acid (a-4).

[Unsaturated carboxylic acid (a-4)]
The unsaturated carboxylic acid (a-4) (hereinafter sometimes simply referred to as “monomer (a-4)”) includes, among acid groups, a carboxy group which has a high reactivity with an epoxy group and an ethylenic unsaturated group. There is no particular limitation as long as it is a monomer having a group. Specific examples of the monomer include (meth) acrylic acid, itaconic acid, crotonic acid, cinnamic acid, 2- (meth) acryloyloxyethylsuccinic acid, 2- (meth) acryloyloxyethylphthalic acid, 2- (meth) acryloyl Examples thereof include oxyethylhexahydrophthalic acid. In particular, (meth) acrylic acid is preferable from the viewpoints of easy availability and good reactivity.

[Polybasic acid anhydride (a-5)]
The polybasic acid anhydride is not particularly limited as long as it has an acid anhydride structure having good reactivity with a hydroxy group, but a polybasic acid anhydride having a ring structure that does not generate a by-product after the reaction is preferable. Specifically, 1,2,3,6-tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, bicyclo [2.2.1] heptane-2,3-dicarboxylic anhydride , Methylbicyclo [2.2.1] heptane-2,3-dicarboxylic acid anhydride, succinic anhydride, octenylsuccinic anhydride and the like.

The reaction ratio of the unsaturated carboxylic acid (a-4) is preferably 10 to 70 mol%, more preferably 10 to 70 mol% when the total amount of the monomers (M1) constituting the epoxy group-containing copolymer (P1) is 100 mol%. It is preferably 15 to 65 mol%. When the blending ratio of the unsaturated carboxylic acid (a-4) is 10 mol% or more, sufficient curability can be exhibited in the photosensitive resin composition. On the other hand, when it is 70 mol% or less, a sufficient mixing ratio of the monomer (a-1A) and / or the monomer (a-1B) and the monomer (a-2) is ensured to obtain desired thermal decomposition resistance and refractive index. The copolymer (A) having is obtained. The ratio of the unsaturated carboxylic acid (a-4) to be added to the number of moles of the epoxy group contained in the epoxy group-containing copolymer (P1) is preferably 90 to 100 mol%, and It is preferably 95 to 100 mol%. When the addition ratio of the unsaturated carboxylic acid (a-4) is 90% or more, sufficient curability can be exhibited when the photosensitive resin composition is prepared, and other fluororesins having no photocurability can be obtained. It is possible to provide a photosensitive resin composition having a good affinity as compared with the photosensitive resin composition in which the photocurable component of (1) is mixed.

The reaction ratio of the polybasic acid anhydride (a-5) is not particularly limited as long as the reaction is performed so that the acid value of the copolymer (A1) is 20 KOHmg / g or more. When the total amount of the monomers (M1) constituting the epoxy group-containing copolymer (P1) is 100 mol%, it is preferably 5 to 30 mol%, more preferably 5 to 20 mol%. When the blending ratio of the polybasic acid anhydride (a-5) is 5 mol% or more, the copolymer (A1) having a desired alkali developability can be obtained. On the other hand, when it is 30 mol% or less, the compounding ratio of the monomer (a-1A) and / or the monomer (a-1B), the monomer (a-2) and the monomer (a-4) is sufficiently secured to obtain a desired amount. The copolymer (A1) having the above-mentioned thermal decomposition resistance, refractive index, and curability can be obtained. Further, based on the total number of moles of the hydroxy group generated by ring opening of the epoxy group of the epoxy group-containing copolymer (P1) and the hydroxy group of the monomer (a-6), the polybasic acid anhydride (a- The addition ratio of 5) is preferably 10 to 90 mol%, more preferably 10 to 70 mol%. When the addition ratio of the polybasic acid anhydride (a-5) is 10 mol% or more, the copolymer (A1) having a desired alkali developability can be obtained. Further, when the content is 90% mol% or less, the unreacted product of the polybasic acid anhydride (a-5) does not remain and the desired copolymer (A1) is obtained.

The unsaturated group-containing copolymer (A1) preferably has a structure represented by the following formula (6).

(In the formula (6), X and X ′ each independently represent a hydrogen atom, a linear or branched hydrocarbon group having 1 to 4 carbon atoms, and R 1 and R 2 are each independently It is a hydrocarbon group having 1 to 20 carbon atoms which may have a hydrogen atom, a carboxy group or a substituent, and may have a cyclic structure connecting R1 and R2.
R11 is a substituent having a bridged cyclic hydrocarbon group having 10 to 20 carbon atoms. L is a chain of any one of —O—, —O—CH ₂ —CH (OH) —CH ₂ —, and —O—NH—C (═O) —CH ₂ —CH ₂ —. Each Z independently represents a hydrogen atom, a fluorine atom, a CF ₃ group, a C ₂ F ₅ group, a C ₃ F ₇ group or a hydroxy group, and n is an integer of 0 to 12. However, in the formula (6), at least three fluorine atoms are included.
R12 to R14 each independently represent a hydrogen atom or a methyl group. One of R15 is a hydroxy group and the other is a substituent represented by the following chemical formula (7). Further, one of R16 is a substituent represented by the following chemical formula (7), and the other is a substituent represented by the following chemical formula (8). L ′ is a divalent hydrocarbon group having 1 to 6 carbon atoms which may have a substituent, and L ″ is a hydrogen atom or a hydrocarbon group which connects L ″ and L ′ to form a cyclic structure.
x1, x2, y, a, b, and c are molar ratios of the respective structural units, y, a, and b are larger than 0, and x1, x2, and c may be 0. However, x1 and x2 are never 0 at the same time. The bonding order of each structural unit is not limited to that shown in the formula, and a block polymer or a random polymer may be formed. * Represents a bond. )

(In the formula (7), R17 represents a hydrogen atom or a methyl group. * Represents a bond.)

(In the formula (8), R18 and R19 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms which may have a substituent, and has a cyclic structure connecting R18 and R19. May be. * Represents a bond.)

R11 is a substituent having a bridged cyclic hydrocarbon group having 10 to 20 carbon atoms, and is preferably an adamantyl group or a group having a structure represented by the following formula (5). ‥

(In formula (5), R6 to R8 each represent a hydrogen atom or a methyl group. R9 and R10 may be a hydrogen atom or a methyl group, or may be bonded to each other to form a saturated or unsaturated ring. The ring is preferably a 5-membered ring or a 6-membered ring. * Represents a bond linked to the (meth) acrylate R11.)

X, X ', R1 and R2 in the formula (6) are the same as those described in the formula (1).

[Method for producing unsaturated group-containing copolymer (A1)]
The unsaturated group-containing copolymer (A1) according to the present invention is obtained by adding a polymerization inhibitor and a catalyst to a solution of the copolymer (P1) having an epoxy group and then adding the unsaturated carboxylic acid (a-4). After the addition, the epoxy group is subjected to a ring-opening addition reaction under the condition of 50 to 150 ° C., preferably 80 to 130 ° C., and then the polybasic acid anhydride (a-5) is added to perform the ring-opening addition reaction of the epoxy group. It can be produced by reacting under the same conditions as.

When reacting the unsaturated carboxylic acid (a-4) and then the polybasic acid anhydride (a-5), it is used for the copolymerization reaction when producing the above-mentioned copolymer (P1) having an epoxy group. Since there is no particular problem even if the solvent is contained, the reaction can be carried out without removing the solvent after the completion of the copolymerization reaction. Here, the polymerization inhibitor is added to prevent gelation due to polymerization of the introduced double bond. The type is not particularly limited, and specific examples thereof include hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, dibutylhydroxytoluene and the like. The catalyst is also not particularly limited, but specifically, tertiary amines such as triethylamine, quaternary ammonium salts such as triethylbenzylammonium chloride, phosphorus compounds such as triphenylphosphine, and organic metals such as chromium and tin. A compound etc. are mentioned.

[Second embodiment]
The second embodiment of the copolymer (A) of the present invention is a hydroxy obtained by ring-opening addition of the carboxyl group-containing copolymer (P2) to the epoxy group of the epoxy group-containing (meth) acrylate (a-3). It is an unsaturated group-containing copolymer (A2-I) having a group and is characterized by having an acid value of 20 KOHmg / g or more. The epoxy group-containing copolymer (P2) is a structural unit derived from the polymerizable monomer (a-1A) having a bridged cyclic hydrocarbon group having 10 to 20 carbon atoms and the polymerizable monomer represented by the chemical formula (1). At least one selected from the group consisting of structural units derived from (a-1B), a structural unit derived from the fluorine-containing (meth) acrylate (a-2) represented by the chemical formula (2), and an unsaturated carboxylic acid. It is a copolymer containing a structural unit derived from (a-4). Here, the (meth) acrylate means one or more selected from methacrylate and acrylate.

[Carboxy group-containing copolymer (P2)]
The carboxy group-containing copolymer (P2) (hereinafter sometimes simply referred to as “copolymer (P2)”) related to the copolymer (A2-I) of the present embodiment has 10 to 20 carbon atoms. At least one selected from the group consisting of a polymerizable monomer having a bridged cyclic hydrocarbon group (a-1A) and a polymerizable monomer represented by the chemical formula (1) (a-1B); ) Is a copolymer of the monomer (M2) containing the fluorine-containing (meth) acrylate (a-2) and the unsaturated carboxylic acid (a-4). The fluorine equivalent of the carboxy group-containing copolymer (P2) is preferably 100 g / mol or less, more preferably 30 to 100 g / mol, and further preferably 40 to 100 g / mol.
The monomer (M2) of the copolymer (P2) of this embodiment preferably further contains a hydroxy group-containing (meth) acrylate (a-6). When the hydroxy group-containing (meth) acrylate (a-6) is copolymerized, alkali developability can be further enhanced. Further, the above-mentioned monomer (M2) of the copolymer (P2) of the present embodiment may contain other polymerizable monomer (a-7).

It contains a polymerizable monomer (a-1A), a polymerizable monomer (a-1B), a fluorine-containing (meth) acrylate (a-2), an unsaturated carboxylic acid (a-4), and a hydroxy group according to this embodiment. The (meth) acrylate (a-6) and the other polymerizable monomer (a-7) are the same as those described in the first embodiment, and the description thereof will be omitted.

[Ratio of structures derived from each monomer of carboxy group-containing copolymer (P2)]
In the copolymer (P2) according to the present invention, the ratio of each monomer-derived structure is the value of the molar ratio of each polymerizable monomer added for the copolymerization reaction. The mixing ratio (molar ratio) of each monomer is not particularly limited, but when the total amount of the monomers (M2) constituting the carboxy group-containing copolymer (P2) is 100 mol%, the monomer (a-1A) and The total blending ratio of the monomer (a-1B) is preferably 1 to 40 mol%, more preferably 2 to 20 mol%. When the mixing ratio of the monomer (a-1A) and the monomer (a-1B) is 1 mol% or more, desired thermal decomposition resistance, thermal yellowing resistance, and good solubility in a solvent can be obtained. On the other hand, when the blending ratio is 40 mol% or less, the blending ratio of the monomer (a-2) or the monomer (a-4) becomes sufficiently large, and the copolymer (A) having a desired refractive index and curability. Is obtained. The mixing ratio of the monomer (a-2) is preferably 20 to 90 mol%, more preferably 30 to 85 mol%. When the blending ratio of the monomer (a-2) is 20 mol% or more, the copolymer (A) having a sufficiently low refractive index can be obtained. When the blending ratio of the monomer (a-2) is 90 mol% or less, the blending ratio of the monomer (a-1A) and / or the monomer (a-1B) and the monomer (a-4) is sufficiently high, and the desired amount is obtained. A copolymer (A) having thermal decomposition resistance, curability, and good solubility in a solvent can be obtained. The mixing ratio of the monomer (a-4) is preferably 9 to 70 mol%, more preferably 13 to 65 mol%. When the blending ratio of the monomer (a-4) is 9 mol% or more, sufficient curability can be exhibited when the photosensitive resin composition is prepared, and the fluororesin and other photocurable resins which do not have photocurability can be obtained. It is possible to provide a photosensitive resin composition having good affinity as compared with a photosensitive resin composition in which a photocurable component is mixed. If the blending ratio of the monomer (a-4) is 70 mol% or less, the blending ratio of the monomer (a-1A) and / or the monomer (a-1B) and the monomer (a-2) will be sufficiently high, and the desired amount will be obtained. A copolymer (A2) having thermal decomposition resistance and refractive index is obtained. The mixing ratio of the monomer (a-6) is preferably 0 to 50 mol%, more preferably 0 to 20 mol%.

[Copolymerization Reaction (Method for Producing Carboxy Group-Containing Copolymer (P2))]
The carboxy group-containing copolymer (P2) according to the present invention can be produced by using a copolymerization reaction, like the copolymer (P1) according to the first embodiment.

The fluorine equivalent of the carboxyl group-containing copolymer (P2) is the mass of the polymer per the number of moles of the fluorine atom, and is a calculated value calculated based on the amount of the monomer used. If this value is 100 g / mol or less, the refractive index of the acrylic resin that exhibits photocurability by adding an epoxy group-containing (meth) acrylate (a-3) or a polybasic acid anhydride (a-5) will be high. It is possible to obtain a sufficiently low copolymer (A2) of the present invention. The lower this value is, the lower the refractive index of the copolymer (A2) is, but the solubility of the copolymer in a solvent is lowered, and the affinity with other photosensitive resin compositions is deteriorated. There is a fear. Therefore, the fluorine equivalent is preferably 30 to 100 g / mol, more preferably 40 to 100 g / mol.

[Unsaturated group-containing copolymer (A2-I)]
The unsaturated group-containing copolymer (A2-I) is obtained by ring-opening addition of the carboxy group-containing copolymer (P2) to the epoxy group of the epoxy group-containing (meth) acrylate (a-3).

When the copolymer (A2-I) of the present embodiment contains a structural unit derived from an addition reaction in which the epoxy group-containing (meth) acrylate (a-3) participates, a double bond excellent in photosensitivity is introduced. At the same time, a hydroxy group can be obtained by ring opening of the epoxy group. Curability can be exhibited by light or heat, and alkali developability can be exhibited. With this structural unit, sufficient hardness of the cured product is exhibited, and high solvent resistance is exhibited. Furthermore, the carboxy group can be introduced at the same time by leaving the whole amount of the carboxy group contained in the carboxy group-containing copolymer (P2) without reacting with the epoxy group. By introducing a carboxy group or a hydroxy group as the alkali developing group, the affinity of the copolymer with the alkali developing solution is increased. By using such a copolymer, a highly precise cured pattern can be formed and strict dimensional accuracy is realized.

The epoxy group-containing (meth) acrylate (a-3) and polybasic acid anhydride (a-5) according to the present embodiment are the same as those according to the first embodiment, and the description thereof will be omitted.

The reaction ratio of the epoxy group-containing (meth) acrylate (a-3) is not particularly limited as long as the reaction is performed so that the acid value of the copolymer (A2-I) is 20 KOHmg / g or more. When the total amount of the monomers (M2) constituting the carboxy group-containing copolymer (P2) is 100 mol%, it is preferably 5 to 40 mol%, more preferably 5 to 20 mol%. When the compounding ratio of the epoxy group-containing (meth) acrylate (a-3) is 5 mol% or more, sufficient curability can be exhibited in the photosensitive resin composition. On the other hand, when it is 40 mol% or less, the compounding ratio of the monomer (a-1A) and / or the monomer (a-1B), the monomer (a-2) and the monomer (a-4) is sufficiently secured to obtain a desired amount. A copolymer (A2-I) having thermal decomposition resistance, refractive index, and alkali developability can be obtained. Further, the ratio of the epoxy group-containing (meth) acrylate (a-3) to be added to the number of moles of the carboxy group contained in the carboxy group-containing copolymer (P2) is preferably 10 to 90 mol%. %, And more preferably 10 to 70 mol%. When the addition ratio of the epoxy group-containing (meth) acrylate (a-3) is 10 mol% or more, sufficient curability can be exhibited when the photosensitive resin composition is prepared and photocurability is not exerted. It is possible to provide a photosensitive resin composition having good affinity as compared with a photosensitive resin composition in which a fluororesin and another photocurable component are mixed. Further, when it is 90% mol% or less, the unreacted product of the epoxy group-containing (meth) acrylate (a-3) does not remain, and the desired copolymer (A2-I) is obtained.

The unsaturated group-containing copolymer (A2-I) preferably has a structure represented by the following formula (9-I).

(In formula (9-I), X and X ′ each independently represent a hydrogen atom, a linear or branched hydrocarbon group having 1 to 4 carbon atoms, and R 1 and R 2 are each independently A hydrogen atom, a carboxy group or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent and may have a cyclic structure connecting R1 and R2.
R11 is a substituent having a bridged cyclic hydrocarbon group having 10 to 20 carbon atoms. L is a chain of any one of —O—, —O—CH ₂ —CH (OH) —CH ₂ —, and —O—NH—C (═O) —CH ₂ —CH ₂ —. Each Z independently represents a hydrogen atom, a fluorine atom, a CF ₃ group, a C ₂ F ₅ group, a C ₃ F ₇ group or a hydroxy group, and n is an integer of 0 to 12. However, in the formula (9-I), at least three fluorine atoms are contained.
R12, R13, and R20 each independently represent a hydrogen atom or a methyl group, one of R21 is a hydrogen atom, and the other is a substituent represented by the following chemical formula (10).
x1, x2, y, d, and e are molar ratios of the respective constituent units, y, d, and e are larger than 0, and x1 and x2 may be 0. However, x1 and x2 are never 0 at the same time. The bonding order of each structural unit is not limited to that shown in the formula, and a block polymer or a random polymer may be formed. )

(In the formula (10), R22 represents a hydrogen atom or a methyl group, L ′ ″ represents a divalent hydrocarbon group having 1 to 6 carbon atoms, which may have a substituent, and is represented by the formula (9- One of R21s in I) (that is, R of the formula (10) where R is not linked may be connected to form a ring structure. * Represents a bond)

R11, X, X ', R1 and R2 in formula (9-I) are the same as in formula (6).

[Method for producing unsaturated group-containing copolymer (A2-I)]
The unsaturated group-containing copolymer (A2-I) according to the present invention is obtained by adding a polymerization inhibitor and a catalyst to a solution of the copolymer (P2) having a carboxy group, and then adding an epoxy group-containing (meth) acrylate ( It can be produced by adding a-3) and reacting under the same conditions as in the ring-opening addition reaction of the epoxy group of the first embodiment.

[Third embodiment]
The third embodiment of the copolymer (A) of the present invention is a hydroxy obtained by ring-opening addition of the carboxyl group-containing copolymer (P2) to the epoxy group of the epoxy group-containing (meth) acrylate (a-3). An unsaturated group-containing copolymer (A2-II) obtained by adding a polybasic acid anhydride (a-5) to a hydroxy group of an unsaturated group-containing copolymer (A2-I) having a group, The acid value is 20 KOHmg / g or more. Since the unsaturated group-containing copolymer (A2-I) according to the third embodiment is the same as the unsaturated group-containing copolymer (A2-I) according to the second embodiment, the description thereof will be omitted.

[Unsaturated group-containing copolymer (A2-II)]
The unsaturated group-containing copolymer (A2-II) is an unsaturated group obtained by adding a polybasic acid anhydride (a-5) to the hydroxy group of the unsaturated group-containing copolymer (A2-I). It is a containing copolymer. The hydroxy group is a hydroxy group formed by ring-opening addition of the carboxyl group-containing copolymer (P2) to the epoxy group of the epoxy group-containing (meth) acrylate (a-3) and a monomer (a-6) which is an optional component. ) Is a hydroxy group.

The copolymer (A2-II) of the present embodiment contains the structural unit derived from the addition reaction in which the epoxy group-containing (meth) acrylate (a-3) and the polybasic acid anhydride (a-5) participate. At the same time as introducing a double bond having excellent photosensitivity, a hydroxy group having excellent alkali developability can be obtained by ring opening of the epoxy group. With this structural unit, sufficient hardness of the cured product is exhibited, and high solvent resistance is exhibited. Further, the carboxy group can be introduced at the same time by leaving the whole amount of the carboxy group contained in the carboxy group-containing copolymer (P2) with the epoxy group and leaving a part thereof. It is also possible to add a polybasic acid anhydride (a-5) to the hydroxy group to increase the amount of carboxylic acid introduced.
By introducing a carboxy group or a hydroxy group as an alkali developing group, the affinity of the copolymer with an alkali developing solution is increased, a highly precise curing pattern can be formed, and strict dimensional accuracy is realized.
In addition, the carboxylic acid can be introduced at the same time by not reacting the whole amount of the unsaturated carboxylic acid with the epoxy group and leaving a part thereof. Furthermore, the amount of carboxylic acid introduced can be increased by adding a polybasic acid anhydride to the obtained hydroxy group.

The reaction ratio of the epoxy group-containing (meth) acrylate (a-3) is the same as the reaction ratio of the epoxy group-containing (meth) acrylate (a-3) of the copolymer (A2-I) of the second embodiment. ..

The reaction ratio of the polybasic acid anhydride (a-5) is preferably 5 to 30 mol% when the total amount of the monomers (M2) constituting the carboxy group-containing copolymer (P2) is 100 mol%. It is more preferably 5 to 20 mol%. When the blending ratio of the polybasic acid anhydride (a-5) is 5 mol% or more, the alkali developability of the copolymer (A2-I) can be further enhanced. On the other hand, when the amount is 30 mol% or less, the compounding ratio of the monomer (a-1A) and / or the monomer (a-1B) and the monomer (a-2) is sufficiently secured to obtain desired thermal decomposition resistance and refractive index. A copolymer (A2-II) having is obtained. In addition, the polybasic acid anhydride (a) is added to the total number of moles of the epoxy group-containing (meth) acrylate (a-3) and the monomer (a-6) of the unsaturated group-containing copolymer (A2-I). The ratio of -5) is preferably 10 to 90 mol%, more preferably 10 to 70 mol%. When the addition ratio of the polybasic acid anhydride (a-5) is 10 mol% or more, a copolymer (A2-II) having a desired alkali developability can be obtained. Further, when the content is 90 mol% or less, the unreacted product of the polybasic acid anhydride (a-5) does not remain, and the desired copolymer (A2-II) is obtained.

The unsaturated group-containing copolymer (A2-II) of this embodiment preferably has a structure represented by the following formula (9-II).

(In the formula (9-II), X and X ′ each independently represent a hydrogen atom, a linear or branched hydrocarbon group having 1 to 4 carbon atoms, and R 1 and R 2 are each independently A hydrogen atom, a carboxy group or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent and may have a cyclic structure connecting R1 and R2.
R11 is a substituent having a bridged cyclic hydrocarbon group having 10 to 20 carbon atoms. L is a chain of any one of —O—, —O—CH ₂ —CH (OH) —CH ₂ —, and —O—NH—C (═O) —CH ₂ —CH ₂ —. Each Z independently represents a hydrogen atom, a fluorine atom, a CF ₃ group, a C ₂ F ₅ group, a C ₃ F ₇ group or a hydroxy group, and n is an integer of 0 to 12. However, in the formula (9-II), at least three fluorine atoms are contained.
R12, R13, and R20 each independently represent a hydrogen atom or a methyl group, and R23 is a substituent represented by the following chemical formula (8). One of R21 is a hydrogen atom and the other is a substituent represented by the following chemical formula (10).
x1, x2, y, d, e, and f are molar ratios of the respective constituent units, y, d, e, and f are larger than 0, and x1 and x2 may be 0. However, x1 and x2 are never 0 at the same time. The bonding order of each structural unit is not limited to that shown in the formula, and a block polymer or a random polymer may be formed. )

(In the formula (10), R 22 represents a hydrogen atom or a methyl group, L ′ ″ represents a divalent hydrocarbon group having 1 to 6 carbon atoms, which may have a substituent, and is represented by the formula (9- One ring of R21 in II) (that is, R21 in which * in formula (10) is not linked) may be connected to form a ring structure.
* Represents a bond. )

R11, X, X ', R1 and R2 in formula (9-II) are the same as in formula (6).

[Method for producing unsaturated group-containing copolymer (A2-II)]
The unsaturated group-containing copolymer (A2-II) is prepared by producing the unsaturated group-containing copolymer (A2-I) and then adding the polybasic acid anhydride (a-5) to the mixture at 50 to 150 ° C. Preferably, it can be produced by reacting a hydroxy group with a polybasic acid anhydride (a-5) at 80 to 130 ° C.

When the polybasic acid anhydride (a-5) is reacted, there is no particular problem even if the solvent used in the above-mentioned copolymerization reaction is contained. Therefore, the solvent is not removed after the completion of the copolymerization reaction. The reaction can be carried out. Here, the polymerization inhibitor is added to prevent gelation due to polymerization of the introduced double bond. The type is not particularly limited, and specific examples thereof include hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, dibutylhydroxytoluene and the like. The catalyst is also not particularly limited, but specifically, tertiary amines such as triethylamine, quaternary ammonium salts such as triethylbenzylammonium chloride, phosphorus compounds such as triphenylphosphine, and organic metals such as chromium and tin. A compound etc. are mentioned.

[Fourth embodiment]
The fourth embodiment of the copolymer (A) of the present invention is a hydroxy obtained by ring-opening addition of the carboxy group-containing copolymer (P2) to the epoxy group of the epoxy group-containing (meth) acrylate (a-3). An unsaturated group-containing copolymer (A2-I) having a group and a polybasic acid anhydride (a-5) added to the hydroxy group of the unsaturated group-containing copolymer (A2-I). It is characterized by containing a saturated group-containing copolymer (A2-II) and having an acid value of 20 KOHmg / g or more.
The fourth embodiment of the copolymer of the present invention is preferably a mixture of the unsaturated group-containing copolymer (A2-I) and the unsaturated group-containing copolymer (A2-II). The unsaturated group-containing copolymer (A2-I) and the unsaturated group-containing copolymer (A2-II) according to the fourth embodiment are respectively the unsaturated group-containing copolymer (A2) according to the second embodiment. -I) and the unsaturated group-containing copolymer (A2-II) according to the third embodiment, the description thereof will be omitted.

[Method for producing mixture of unsaturated group-containing copolymer (A2-I) and unsaturated group-containing copolymer (A2-II)]
The unsaturated group-containing copolymer (A2-I) and the unsaturated group-containing copolymer (A2-II) are mixed in a mass ratio (A2-I / A2-II) of 5/95 to 95/5, for example. Mix within the range to prepare a copolymer having an acid value of 20 KOHmg / g or more. Alternatively, in the third embodiment, after the unsaturated group-containing copolymer (A2-I) is produced, the polybasic acid anhydride (a-5) is added to the unsaturated group-containing copolymer (A2-II). In producing the compound, the addition amount of the polybasic acid anhydride (a-5) is adjusted to obtain an unsaturated group-containing copolymer (A2-I) and an unsaturated group-containing copolymer (A2-II). It may be a mixture of.

[Characteristics of copolymer]
The molecular weight (polystyrene-equivalent weight average molecular weight) of the copolymer (A) of the present invention obtained in the above-mentioned first embodiment to fourth embodiment is preferably 1,000 to 50,000, more preferably 3,000 to 40,000. .. When this molecular weight is 1,000 or more, the solvent resistance and thermal decomposition resistance of the cured film can be sufficiently secured. On the other hand, when the molecular weight is 50,000 or less, the molecular weight and the viscosity can be controlled in an appropriate range, which is practical.

The acid value (JIS K6901 5.3) of the copolymer (A) of the present invention is 20 KOHmg / g or more, preferably 20 to 300 KOHmg / g, and more preferably 30 to 100 KOHmg / g. If the acid value is less than 20 KOHmg / g, developability may be deteriorated and unexposed portions (non-cured portions) may be generated as residues. On the other hand, when the acid value is 300 KOHmg / g or less, the exposed portion (cured portion) is not easily dissolved in the alkali developing solution.

The hydroxyl equivalent of the copolymer (A) of the present invention is preferably 200 to 4000 g / mol, more preferably 500 to 3000 g / mol. By introducing fluorine, the water repellency of the alkaline developer is increased, but by controlling the hydroxyl group equivalent to 4000 g / mol or less, more preferably 3000 g / mol or less, the water repellency of the alkaline developer is suppressed and good developing property is obtained. Can be realized. On the other hand, when the hydroxyl group equivalent is 200 g / mol or more, the introduction amount of other substituents necessary for the present invention can be sufficiently secured, and desired curability, heat decomposition resistance, heat yellowing and refractive index can be obtained.

The unsaturated group equivalent of the copolymer (A) is preferably 3000 g / mol or less, more preferably 100 to 3000 g / mol, and further preferably 500 to 2000 g / mol. When the unsaturated group equivalent is 100 g / mol or more, it is more effective to further enhance the thermal decomposition resistance and the thermal yellowing resistance. An unsaturated group equivalent of preferably 3000 g / mol or less, more preferably 2000 g / mol or less, is required to impart high sensitivity and desired photocurability.

Also, the refractive index of the copolymer (A) is preferably less than 1.50 under the conditions of 589 nm and 20 ° C. When it is less than 1.50, the refractive index is sufficiently lower than the refractive index of the fluorine-free photocurable acrylic resin, and good low reflectance of the cured film can be obtained.

[Resin composition]
The resin composition of the present invention contains a copolymer (A) and a solvent (B). The resin composition of the present invention may further contain a reactive diluent (C), a photopolymerization initiator (D) and a colorant (E). By containing the photopolymerization initiator (D), a photosensitive resin composition can be obtained.

[Solvent (B)]
The solvent (B) is not particularly limited as long as it is a solvent that does not react with the copolymer (A). As the solvent (B), the same solvent as used in the production of the copolymer (A) can be used, and the solvent contained after the reaction can be used as it is or further added. In addition, when other components are added, they may coexist there. Specific examples of the solvent (B) include propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, ethyl acetate, butyl acetate, isopropyl acetate, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol. Examples thereof include monomethyl ether, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethylene glycol monoethyl ether acetate and diethylene glycol ethyl ether acetate. These may be used alone or in combination of two or more. Among these, glycol ether solvents such as propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate used in the production of the copolymer (A) are preferable.

The blending amount of the solvent (B) in the resin composition or the photosensitive resin composition of the present embodiment is generally 30 to 1000 parts by mass when the total amount of the components excluding the solvent (B) in the composition is 100 parts by mass. Parts, preferably 50 to 800 parts by weight, more preferably 100 to 700 parts by weight. If it is the compounding quantity of this range, it will become a resin composition or a photosensitive resin composition which has suitable viscosity.

[Reactive diluent (C)]
The reactive diluent (C) is not particularly limited, but those containing an ethylenically unsaturated double bond, a vinyl group and a (meth) acryloyloxy group are preferable. Specific examples thereof include aromatic vinyl monomers such as styrene, α-methylstyrene, α-chloromethylstyrene, vinyltoluene, divinylbenzene, diallylphthalate and diallylbenzenephosphonate; polycarboxylic acids such as vinyl acetate and vinyl adipate. Monomers: methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, β-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, ethylene glycol di (meth) acrylate , Diethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylol (Meth) acrylic monomers such as propane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tri (meth) acrylate of tris (hydroxyethyl) isocyanurate; triallyl cyanurate Etc. These may be used alone or in combination of two or more.
Among them, a polyfunctional (meth) acrylate having a plurality of (meth) acryloyloxy groups is preferable, and a polyfunctional (meth) acrylate having three or more (meth) acryloyloxy groups is more preferable.

The compounding amount of the reactive diluent (C) in the resin composition or photosensitive resin composition of the present embodiment is generally 10 when the total amount of the components excluding the solvent (B) in the composition is 100% by mass. ˜90% by mass, preferably 20 to 80% by mass, more preferably 25 to 70% by mass. If it is the compounding quantity of this range, it will become a resin composition or photosensitive resin composition which has suitable viscosity, and a photosensitive resin composition has suitable photocurability.

[Photopolymerization initiator (D)]
The photopolymerization initiator (D) is not particularly limited, but specific examples thereof include benzoin such as benzoin, benzoin methyl ether, and benzoin ethyl ether, and alkyl ethers thereof; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1 , 1-dichloroacetophenone, 4- (1-t-butyldioxy-1-methylethyl) acetophenone and other acetophenones; 2-methylanthraquinone, 2-amylanthraquinone, 2-t-butylanthraquinone, 1-chloroanthraquinone and other anthraquinones Thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone and 2-chlorothioxanthone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzoph Benzophenones such as non-, 4- (1-t-butyldioxy-1-methylethyl) benzophenone, 3,3 ′, 4,4′-tetrakis (t-butyldioxycarbonyl) benzophenone; 2-methyl-1- [ 4- (methylthio) phenyl] -2-morpholino-propan-1-one; 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1; acylphosphine oxides; and xanthone and the like. Be done. These may be used alone or in combination of two or more.

The blending amount of the photopolymerization initiator (D) in the photosensitive resin composition of the present embodiment is 100 parts by mass based on the total amount of the copolymer (A) and the reactive diluent (C) in the photosensitive resin composition. Then, it is generally 0.1 to 30 parts by mass, preferably 0.5 to 20 parts by mass, more preferably 1 to 15 parts by mass. A blending amount within this range results in a photosensitive resin composition having appropriate photocurability.

[Colorant (E)]
The colorant (E) is not particularly limited as long as it can be dissolved or dispersed in the solvent (B), and known dyes or pigments can be used. When a dye is used as the colorant (E), it is possible to obtain a colored pattern having a higher brightness than when a pigment is used, and a good alkali developability is exhibited. On the other hand, when a pigment is used as the colorant (E), the heat resistance of the colored pattern is higher than when a dye is used. Dyes and pigments may be used in combination depending on the required performance and the intended pixel color.

"dye"
As the dye, an acid dye having an acidic group such as a carboxy group, from the viewpoint of solubility in a solvent (B) or an alkali developing solution, interaction with other components in the resin composition for a color filter, heat resistance, and the like, It is preferable to use a salt of an acidic dye with a nitrogen compound, a sulfonamide body of an acidic dye, or the like. Specific examples of such dyes include acid alizarin violet N; acid black 1, 2, 24, 48; acid blue 1, 7, 9, 25, 29, 40, 45, 62, 70, 74, 80, 83, 90. , 92, 112, 113, 120, 129, 147; acid chrome violet K; acid Fuchsin; acid green 1, 3, 5, 25, 27, 50; acid orange 6, 7, 8, 10, 12, 50, 51, 52. , 56, 63, 74, 95; acid
red1, 4, 8, 14, 17, 18, 26, 27, 29, 31, 34, 35, 37, 42, 44, 50, 51, 52, 57, 69, 73, 80, 87, 88, 91, 92, 94, 97, 103, 111, 114, 129, 133, 134, 138, 143, 145, 150, 151, 158, 176, 183, 198, 211, 215, 216, 217, 249, 252, 257, 260, 266, 274; acid violet 6B, 7, 9, 17, 19; acid yellow1, 3, 9, 11, 17, 23, 25, 29, 34, 36, 42, 54, 72, 73, 76, 79 , 98, 99, 111, 112, 114, 116; food yellow 3 and derivatives thereof.
Among these, azo, xanthene, anthraquinone or phthalocyanine acid dyes are preferable. These dyes can be used alone or in combination of two or more, depending on the intended color of the pixel.

"Pigment"
Specific examples of the pigment include C.I. I. Pigment Yellow 1, 3, 12, 13, 14, 15, 16, 17, 20, 24, 31, 53, 83, 86, 93, 94, 109, 110, 117, 125, 128, 137, 138, 139, 147, 148, 150, 153, 154, 166, 173, 194, 214 and other yellow pigments; C.I. I. Pigment Orange 13, 31, 36, 38, 40, 42, 43, 51, 55, 59, 61, 64, 65, 71, 73 and the like; orange pigments; I. Pigment Red 9, 97, 105, 122, 123, 144, 149, 166, 168, 176, 177, 180, 192, 209, 215, 216, 224, 242, 254, 255, 264, 265 and the like; C. I. Pigment Blue 15, 15: 3, 15: 4, 15: 6, 60 and other blue pigments; C.I. I. Pigment Violet 1, 19, 23, 29, 32, 36, 38 and the like violet color pigments; C.I. I. Pigment Green 7, 36, 58 and other green pigments; C.I. I. Pigment Brown 23, 25 and the like brown pigments; C.I. I. Pigment Black 1 and 7, black pigments such as carbon black, titanium black and iron oxide. These pigments can be used alone or in combination of two or more, depending on the intended color of the pixel.

When the colorant (E) is blended in the photosensitive resin composition of the present embodiment, it is preferable that the total amount of the components excluding the solvent (B) in the photosensitive resin composition is 100 parts by mass. The amount is 5 to 80 parts by mass, more preferably 5 to 70 parts by mass, and further preferably 10 to 60 parts by mass.

When a pigment is used as the colorant (E), a known dispersant may be added to the photosensitive resin composition from the viewpoint of improving the dispersibility of the pigment. As the dispersant, it is preferable to use a polymer dispersant having excellent dispersion stability over time. Examples of polymer dispersants include urethane dispersants, polyethyleneimine dispersants, polyoxyethylene alkyl ether dispersants, polyoxyethylene glycol diester dispersants, sorbitan aliphatic ester dispersants, and aliphatic modified esters. Examples include a system dispersant. As such a polymer dispersant, EFKA (manufactured by EFKA CHEMICALS BV (EFKA)), Disperbyk (manufactured by Big Chemie), Disparon (manufactured by Kusumoto Kasei Co., Ltd.), and SOLSPERSE (manufactured by Zeneca) are commercially available. You may use what has been. The blending amount of the dispersant in the photosensitive resin composition of the present embodiment may be appropriately set according to the type of pigment used.

[Composition of resin composition]
In the resin composition of the present embodiment, the copolymer (A) and the solvent (B) are blended in such amounts that the total amount of the components excluding the solvent (B) in the resin composition is 100 parts by mass. (A) is 50 to 100 parts by mass, and the solvent (B) is 30 to 1000 parts by mass, preferably 50 to 800 parts by mass, more preferably 100 to 700 parts by mass.
When the resin composition of the present embodiment contains the reactive diluent (C), the blending amounts of the copolymer (A), the solvent (B) and the reactive diluent (C) are the same as those of the solvent in the resin composition. When the total amount of the components excluding (B) is 100 parts by mass, the copolymer (A) is 10 to 90 parts by mass, the solvent (B) is 30 to 1000 parts by mass, and the reactive diluent (C) is 10 to 10 parts by mass. 90 parts by mass, preferably 20 to 80 parts by mass of the copolymer (A), 50 to 800 parts by mass of the solvent (B), and 20 to 80 parts by mass of the reactive diluent (C), More preferably, the copolymer (A) is 30 to 75 parts by mass, the solvent (B) is 100 to 700 parts by mass, and the reactive diluent (C) is 25 to 70 parts by mass.

The resin composition of the present embodiment, in addition to the above components, in order to impart predetermined properties, known coupling agents, leveling agents, known additives such as thermal polymerization inhibitors, and known colorants. You may mix | blend a filler, a dispersing agent, etc. The blending amount of these additives is not particularly limited as long as the effects of the present invention are not impaired.
[Composition of photosensitive resin composition]

When the resin composition of the present embodiment is a photosensitive resin composition containing a photopolymerization initiator (D), a copolymer (A), a solvent (B), a reactive diluent (C), a photopolymerization initiator When the total amount of the components excluding the solvent (B) in the photosensitive resin composition is 100 parts by mass, the blending amount of (D) is preferably 5 to 80 parts by mass of the copolymer (A) and the solvent (B ) Is 30 to 1000 parts by mass, the reactive diluent (C) is 10 to 90 parts by mass, and the photopolymerization initiator (D) is 0.1 to 30 parts by mass, and more preferably the copolymer (A). Is 8 to 70 parts by mass, the solvent (B) is 50 to 800 parts by mass, the reactive diluent (C) is 20 to 80 parts by mass, and the photopolymerization initiator (D) is 0.5 to 20 parts by mass, More preferably, the copolymer (A) is 10 to 60 parts by mass, the solvent (B) is 100 to 700 parts by mass, and the reactive diluent (C) is 25 to 70 parts by mass. Parts, the photopolymerization initiator (D) is 1 to 15 parts by weight.

When the photosensitive resin composition of the present embodiment contains the colorant (E), the copolymer (A), the solvent (B), the reactive diluent (C), the photopolymerization initiator (D), the colorant When the total amount of the components excluding the solvent (B) in the photosensitive resin composition is 100 parts by mass, the amount of the (E) compounded is generally 5 to 80 parts by mass of the copolymer (A) and the solvent (B). 30 to 1000 parts by mass, reactive diluent (C) 10 to 89.9 parts by mass, photopolymerization initiator (D) 0.1 to 30 parts by mass, colorant (E) 5 to 80 parts by mass. Preferably, the copolymer (A) is 8 to 70 parts by mass, the solvent (B) is 50 to 800 parts by mass, the reactive diluent (C) is 20 to 80 parts by mass, and the photopolymerization initiator (D). Is 0.5 to 20 parts by mass, the colorant (E) is 5 to 70 parts by mass, and more preferably the copolymer (A) is 10 to 60 parts by mass and the solvent (B) is 10 parts by mass. To 700 parts by weight reactive diluent (C) is 25 to 70 parts by weight, the photopolymerization initiator (D) 1 to 15 parts by mass, the colorant (E) is 10 to 60 parts by weight.

[Method for producing resin composition]
The resin composition of the present embodiment can be produced by mixing the above components using a known mixing device. The resin composition of the present embodiment is prepared by first preparing the resin composition containing the copolymer (A) and the solvent (B), and then preparing the reactive diluent (C) and the photopolymerization initiator (D). It is also possible to mix and manufacture. The resin composition can be used for preparing the photosensitive resin composition of the present embodiment, and can also be used for other purposes.

The photosensitive resin composition of the present embodiment obtained as described above has excellent sensitivity to light, and since it has alkali developability, it can be developed by using an alkaline aqueous solution, and thermal decomposition It is possible to provide a high-definition cured product (curing pattern) excellent in heat resistance, heat-resistant yellowing and low reflectance. Therefore, the photosensitive resin composition of the present embodiment, various resists, in particular, a microlens surface capable of suppressing reflected light, a substrate incorporated in an image display device capable of suppressing reflection of external light, a color filter, a black matrix. It is suitable for use as a resist used for manufacturing a column spacer, a protective film, and the like. In addition, the photosensitive resin composition of the present embodiment gives a cured film excellent in various properties such as heat decomposition resistance, heat yellowing, high transparency, and low reflectivity, and therefore various coatings, adhesives, printing It is also suitable for use as a binder for inks and the like.

[Registration]
Next, the resist prepared using the photosensitive resin composition of the present invention will be described. The resist of the present invention refers to a cured film obtained from the above photosensitive resin composition. The resist of one embodiment of the present invention includes a glass substrate, a silicon substrate, a polycarbonate substrate, a polyester substrate, a polyamide substrate, a polyamideimide substrate, a polyimide substrate, an aluminum substrate, a printed wiring board, an array substrate, and other substrates on which the present invention is applied. The photosensitive resin composition is applied and the coating film is exposed to light to cure the exposed portion. Then, by baking, a predetermined cured film can be formed on the substrate. The method for applying the photosensitive resin composition is not particularly limited, but a screen printing method, a roll coating method, a curtain coating method, a spray coating method, a spin coating method, a slit coating method or the like can be used. In addition, after applying the photosensitive resin composition, the solvent (B) may be volatilized by heating using a heating means such as a circulation oven, an infrared heater, or a hot plate, if necessary. The heating conditions are not particularly limited and may be appropriately set depending on the type of photosensitive resin composition used. Generally, heating may be performed at a temperature of 50 ° C. to 120 ° C. for 30 seconds to 30 minutes.

The light source used for the exposure is not particularly limited, but a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, a xenon lamp, a metal halide lamp and the like can be used.
The amount of exposure is also not particularly limited, and may be appropriately adjusted according to the type of photosensitive resin composition used.

The alkaline aqueous solution used for development is not particularly limited, but an aqueous solution of sodium carbonate, potassium carbonate, calcium carbonate, sodium hydroxide, potassium hydroxide or the like; an aqueous solution of an amine compound such as ethylamine, diethylamine or dimethylethanolamine; 3 -Methyl-4-amino-N, N-diethylaniline, 3-methyl-4-amino-N-ethyl-N-β-hydroxyethylaniline, 3-methyl-4-amino-N-ethyl-N-β- Methanesulfonamidoethylaniline, 3-methyl-4-amino-N-ethyl-N-β-methoxyethylaniline and their water-soluble p-phenylenediamine compounds such as sulfates, hydrochlorides or p-toluenesulfonates Etc. can be used. Among these, it is preferable to use an aqueous solution of a p-phenylenediamine compound. In addition, an antifoaming agent or a surfactant may be added to these aqueous solutions, if necessary. Further, it is preferable to wash with water and dry after the development with the above alkaline aqueous solution.

The baking conditions are not particularly limited, and heat treatment may be performed depending on the type of photosensitive resin composition used. Generally, heating may be performed at 130 to 250 ° C. for 10 to 60 minutes.

A desired colored pattern can be formed by sequentially repeating the above-mentioned coating, exposure, development and baking using the photosensitive resin composition for black matrix and the photosensitive resin composition for pixels. .. In the above, the method for forming a colored pattern by photocuring has been described. However, if a photosensitive resin composition containing a curing accelerator and a known epoxy resin is used instead of the photopolymerization initiator (D), an inkjet method can be used. It is also possible to form a desired colored pattern by applying the coating method and then heating.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. In this example, all parts and percentages are based on mass unless otherwise specified.

<Measurement method of molecular weight>
The molecular weight (Mw) means a standard polystyrene-equivalent weight average molecular weight measured by gel permeation chromatography (GPC) under the following conditions.
Column: Showdex (registered trademark) LF-804 + LF-804 (manufactured by Showa Denko KK)
Column temperature: 40 ° C
Sample: 0.2% tetrahydrofuran solution of copolymer (A) Developing solvent: Tetrahydrofuran Detector: Differential refractometer (Showdex RI-71S) (Showa Denko KK)
Flow rate: 1 mL / min

<Method of measuring acid value>
According to JIS K6901 5.3.2, the number of mg of potassium hydroxide required to neutralize the acidic component contained in 1 g of the copolymer (A) was measured.
Measuring device: 776 Dosimat (Metrohm)
Mixed indicator: Mixed indicator of bromothymol blue and phenol red

<Method for measuring hydroxyl equivalent>
It is the mass of the polymer per the number of moles of hydroxy groups, and is a calculated value calculated based on the amount of the monomer used.

<Measuring method of unsaturated group equivalent>
It is the mass of the polymer per mol of the ethylenically unsaturated group, and is a calculated value calculated based on the amount of the monomer used.

<Method of measuring refractive index>
The refractive index means the refractive index of the copolymer (A) measured using a refractometer. The refractive index of the resin composition (sample) containing the copolymer (A) and the solvent (B) of the present invention is measured under the following conditions, and then the refractive index of the solvent (B) is measured under the following conditions. Next, the content (solid content) of the copolymer (A) contained in the sample was measured according to JIS K6901 5.11, and the refractive index of the copolymer (A) alone contained in the sample was calculated using the following formula. calculate.
Measuring device: J-357 Automatic Refractometer (Rudolf Research Analytical)
Measurement wavelength: 589 nm
Measurement temperature: 20 ℃
Refractive index of copolymer (A) alone = (refractive index of sample−refractive index of solvent (B)) ÷ solid content × 100 + refractive index of solvent (B) <measurement method of solid content>
The heating residue when the sample obtained in the following synthesis example was heated at 130 ° C. for 2 hours was measured.

<Method of measuring fluorine equivalent>
It is the mass of the polymer per the number of moles of the fluorine atom, and is a calculated value calculated based on the amount of the monomer used.

A production example of a resin composition (sample) containing the copolymer (A) and the solvent (B) of the present invention is shown below.
<Example 1>
"Synthesis of Copolymer (A)"
302.4 g of propylene glycol monomethyl ether acetate was placed in a flask equipped with a stirrer, a dropping funnel, a condenser, a thermometer, and a gas introduction tube, and the mixture was stirred while substituting with nitrogen and heated to 80 ° C. Next, 9.1 g of dicyclopentanyl methacrylate (a-1A), 237.3 g of 2,2,2-trifluoroethyl methacrylate (a-2), and 88.5 g of glycidyl methacrylate (a-3). 21.0 g of 2,2'-azobis (2,4-dimethylvaleronitrile) (polymerization initiator, 6.0 parts by mass with respect to 100 parts by mass of the monomer mixture) was added dropwise to the monomer mixture consisting of It dripped from the funnel into the said flask. After completion of the dropping, the mixture was stirred at 80 ° C. for 2 hours to carry out a copolymerization reaction to obtain an epoxy group-containing copolymer (P1).

Next, after the inside of the flask was replaced with air, 43.5 g of acrylic acid (a-4), 1.1 g of triphenylphosphine (catalyst, monomer (a-1A), (a-2), (a-2) -3), 0.3 parts by mass relative to 100 parts by mass of (a-4) in total, and 1.1 g of hydroquinone monomethyl ether (polymerization inhibitor, monomer (a-1A), (a-2), After adding (a-3) and (a-4) 0.3 parts by mass to the total 100 parts by mass) and reacting at 120 ° C. for 10 hours, 41.5 g of succinic anhydride (a-5) Was added and the mixture was reacted for 1 hour to obtain a solution containing the copolymer (A) of Example 1 consisting of the unsaturated group-containing copolymer (A1). Then, to the solution containing this copolymer, 269.8 g of propylene glycol monomethyl ether acetate was added as a solvent (B), and sample No. Got 1. The blending ratio of each monomer when the total amount of the monomers (a-1A), (a-2) and (a-3) is calculated as 100 mol%, and the fluorine equivalent of the epoxy group-containing copolymer (P1), Table 1 shows the molecular weight, acid value, hydroxyl group equivalent, unsaturated group equivalent, and refractive index of the copolymer (A1).

<Examples 2 to 6, Comparative Examples 1 to 3>
"Synthesis of Copolymer (A)"
A solution containing each of the copolymers (A) of Examples 2 to 6 and Comparative Examples 1 to 3 was produced in the same manner as in Comparative Example 1 except that the mixing ratios of the monomers shown in Table 1 were used. Propylene glycol monomethyl ether acetate was added as B), and sample No. 2 to 6, No. 9-11 were obtained. Table 1 shows the fluorine equivalent of the epoxy group-containing copolymer (P1), the molecular weight of the copolymer (A1), the acid value, the hydroxyl group equivalent, the unsaturated group equivalent, and the refractive index contained in each sample.

<Example 7>
"Synthesis of Copolymer (A)"
In the same manner as in Example 1, 492.9 g of propylene glycol monomethyl ether acetate was placed in the flask, stirred while substituting with nitrogen, and heated to 80 ° C. Next, 11.4 g of dicyclopentanyl methacrylate (a-1A), 295.3 g of 2,2,2-trifluoroethyl methacrylate (a-2), and 66.7 g of methacrylic acid (a-4). 22.4 g of 2,2'-azobis (2,4-dimethylvaleronitrile) (polymerization initiator, 6.0 parts by mass with respect to 100 parts by mass of the monomer mixture) was added dropwise to the monomer mixture consisting of It dripped from the funnel into the said flask. After completion of the dropping, the mixture was stirred at 80 ° C. for 2 hours to carry out a copolymerization reaction to obtain a carboxy group-containing copolymer (P2). Next, after the air in the flask was replaced with air, 36.7 g of glycidyl methacrylate (a-3), 1.2 g of triphenylphosphine (catalyst, monomer (a-1A), (a-2), (a -3), 0.3 parts by mass relative to 100 parts by mass of (a-4) in total, and 1.2 g of hydroquinone monomethyl ether (polymerization inhibitor, monomer (a-1A), (a-2), (0.3 parts by mass relative to 100 parts by mass of (a-3) and (a-4) in total) and reacted at 120 ° C. for 5 hours to prepare the unsaturated group-containing copolymer (A2-I). A solution containing the copolymer (A) of Example 7 was obtained. Next, to the solution containing this copolymer, 118.8 g of propylene glycol monomethyl ether acetate was added as a solvent (B), and sample No. Got 7. When the total amount of the monomers (a-1A), (a-2) and (a-4) is calculated as 100 mol%, the mixing ratio of each monomer and the fluorine equivalent of the carboxy group-containing copolymer (P2) Table 2 shows the molecular weight, acid value, hydroxyl group equivalent, unsaturated group equivalent, and refractive index of the polymer (A2).

<Example 8>
"Synthesis of Copolymer (A)"
A copolymer (A) of Example 8 was produced in the same manner as in Example 7 except that the mixing ratios of the monomers shown in Table 1 were used, and propylene glycol monomethyl ether acetate was added as a solvent (B) to obtain a sample. No. Got 8. Table 2 shows the molecular weight, acid value, hydroxyl group equivalent, unsaturated group equivalent, and refractive index of the copolymer (A2) contained in the sample.

(Examples 9 to 16 and Comparative Example 4)
Next, sample No. 1-8, No. 10 was used to prepare a transparent photosensitive resin composition.
<Preparation of transparent photosensitive resin composition>
Sample No. 1-8, No. 10 parts by mass of pentaerythritol tetraacrylate (reactive diluent (C)) and 10 parts by mass of 2,2-dimethoxy-2-phenylacetophenone (photopolymerization initiator (D)) per 100 parts by mass of the solid content of 10. Was added, and then propylene glycol monomethyl ether acetate was added so that the solvent (B) was 210 parts by mass to prepare a transparent photosensitive resin composition.
The residue of the sample excluding the solvent (propylene glycol monomethyl ether acetate) is defined as "solid content".

<Pattern formation by transparent photosensitive resin composition>
The prepared transparent photosensitive resin composition was spin-coated on a 5 cm square glass substrate (alkali-free glass substrate) so that the average thickness of the final cured coating film would be 2.5 μm, and then 3 ° C. at 100 ° C. The solvent was volatilized by heating for a minute. Next, the entire surface of the coating film was exposed with an apparatus (exposure amount: 80 mJ / cm ² ), photocured, and then baked at 230 ° C. for 30 minutes to obtain a transparent resist which was a cured coating film.

<Evaluation of transparent resist>
The transparent resist was evaluated for heat decomposition resistance and heat yellowing.
(1) Evaluation of thermal decomposition resistance Evaluation was carried out by thermogravimetric analysis (TGA) using a sample obtained by cutting out a coating film formed on a glass substrate. In this analysis, this sample was heated to 220 ° C. at a temperature rising rate of 10 ° C./min, held for 2 hours, and then weighed. The weight change rate between the sample after heating and the sample before heating was determined. The weight change rate was measured up to -5.0%, and those with a larger weight change were judged to have poor thermal decomposition resistance.

(2) Evaluation of heat-resistant yellowing The coating film formed on a glass substrate was allowed to stand in a dryer at 230 ° C for 1 hour in a nitrogen gas atmosphere, and the color change (ΔE ^* ab) of the coating film before and after heat treatment was evaluated. Comparison was performed using a color difference meter SE2000 manufactured by Nippon Denshoku Industries Co., Ltd.

Tables 3 and 4 show the evaluation results of the thermal decomposition resistance and the yellowing resistance of the transparent resist.

(Examples 17 to 24 and Comparative Examples 5 to 7)
Next, sample No. 1 to 11 were used to prepare a black photosensitive resin composition.
<Preparation of black pigment dispersion>
In a SUS container filled with 180 parts by mass of zirconia beads having a diameter of 0.5 mm, 10 parts by mass of carbon black, 34 parts by mass of propylene glycol monomethyl ether acetate, and 6 parts by mass of a dispersant (Disperbyk-manufactured by BYK Japan KK 161) was added and mixed by a paint shaker for 3 hours and dispersed to obtain a black pigment dispersion liquid.

<Preparation of black photosensitive resin composition>
Sample No. 67 parts by mass of dipentaerythritol hexaacrylate (reactive diluent (C)), ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H, relative to 100 parts by mass of the solid content of 1 to 11 -Carbazol-3-yl-]-,-1- (O-acetyloxime) (photopolymerization initiator (D)) 13 parts by mass, solid content of the black pigment dispersion (colorant (E)) 180 parts by mass After the addition, propylene glycol monomethyl ether acetate was added so that the solvent (B) was 670 parts by mass to prepare a black photosensitive resin composition.
The solid content of the black pigment dispersion is defined as the residue obtained by removing the solvent (propylene glycol monomethyl ether acetate) from the black pigment dispersion.

<Pattern formation with black photosensitive resin composition (with development)>
The prepared black photosensitive resin composition was spin-coated on a 5 cm square glass substrate (alkali-free glass substrate) so that the average thickness of the final cured coating film would be 1.0 μm, and then 3 ° C. at 100 ° C. The solvent was volatilized by heating for a minute. Next, a line-and-space or dot-pattern photomask was placed on the substrate to expose the coating film (exposure amount 300 mJ / cm ² ), and after photocuring, a 0.2 mass% potassium hydroxide aqueous solution was used. It was developed and further baked at 230 ° C. for 30 minutes to obtain a black resist as a cured coating film.

<Pattern formation with black photosensitive resin composition (no development)>
The prepared black photosensitive resin composition was spin-coated on a 5 cm square glass substrate (alkali-free glass substrate) so that the average thickness of the final cured coating film would be 1.0 μm, and then 3 ° C. at 100 ° C. The solvent was volatilized by heating for a minute. Next, the entire surface of the coating film was exposed (exposure amount 300 mJ / cm ² ), photocured, and then baked at 230 ° C. for 30 minutes to obtain a black resist as a cured coating film.

<Evaluation of black resist>
The black resist was evaluated for developability, solvent resistance, and reflectance.

(1) Evaluation of solvent resistance A coating film prepared by pattern formation (with development) using a black photosensitive resin composition is dipped in N-methyl-2-pyrrolidone together with a glass substrate, and then in an oven at 100 ° C for 15 minutes. After leaving, the presence or absence of color loss was visually confirmed and evaluated according to the following criteria.
◯: There is no color loss in the pattern x: There is color loss in the pattern

(2) Evaluation of developability In pattern formation (with development) using the black photosensitive resin composition, during development with a 0.2 mass% potassium hydroxide aqueous solution, the time taken until the pattern began to be visible was measured. The measurement time was up to 180 seconds, and when the pattern was not visible by then, it was judged that development was not possible. Further, the development form (how the unexposed portion is removed) was visually confirmed and evaluated according to the following criteria.
◯: The unexposed portion is dissolved in the developing solution ×: The unexposed portion is peeled off

(3) Evaluation of reflectance The reflectance at 550 nm of the coating film prepared by pattern formation (without development) using the black photosensitive resin composition was measured using a spectrophotometer UV-1650PC manufactured by Shimadzu Corporation. ..

Tables 5 and 6 show the evaluation results of the developability, solvent resistance, and reflectance of the black resist.

As can be seen from the results of Tables 3 to 6, in Examples 9 to 24, by using the copolymer (A) of the present invention, excellent thermal decomposition resistance, thermal yellowing resistance, solvent resistance, and developability were obtained. A resist exhibiting low reflectivity was obtained. On the other hand, in Comparative Examples 4 to 7, since the copolymer of the present invention was not used, any resist having insufficient performance was obtained.

From the above, according to the present invention, it is possible to provide a copolymer (A) having excellent alkali developability and an excellent low refractive index while exhibiting photocurability. In addition, the photosensitive resin composition of the present invention can provide a resist that contributes to low reflection and high definition of all electronic material members such as microlenses and image display devices.

Claims

The unsaturated carboxylic acid (a-4) is ring-opened and added to the epoxy group of the epoxy group-containing copolymer (P1), and the hydroxy group formed by ring opening of the epoxy group is added to the polybasic acid anhydride ( a-5) which is a copolymer (A1) to which a-5) is added,
The epoxy group-containing copolymer (P1) is
Consisting of a structural unit derived from a polymerizable monomer (a-1A) having a bridged cyclic hydrocarbon group having 10 to 20 carbon atoms and a structural unit derived from a polymerizable monomer (a-1B) represented by the following chemical formula (1) At least one selected from the group;
A structural unit derived from a fluorine-containing (meth) acrylate (a-2) represented by the following chemical formula (2),
A copolymer containing a structural unit derived from an epoxy group-containing (meth) acrylate (a-3),
A copolymer having an acid value of 20 KOHmg / g or more.

(X and X ′ in the formula (1) each independently represent a hydrogen atom, a linear or branched hydrocarbon group having 1 to 4 carbon atoms, and R 1 and R 2 each independently. A hydrogen atom, a carboxy group, or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and may have a cyclic structure connecting R1 and R2.)

(In the formula (2), R3 represents a hydrogen atom or a methyl group, L represents —O—, —O—CH 2 —CH (OH) —CH 2 —, —O—NH—C (═O) —CH. 2 --CH 2-, each Z independently represents a hydrogen atom, a fluorine atom, a CF 3 group, a C 2 F 5 group, a C 3 F 7 group or a hydroxy group, and n is 0 to It is an integer of 12. However, at least three fluorine atoms are included in the formula (2).
An unsaturated group-containing copolymer (A2-I) having a hydroxy group formed by ring-opening addition of the carboxyl group-containing copolymer (P2) to the epoxy group of the epoxy group-containing (meth) acrylate (a-3), And an unsaturated group-containing copolymer (A2-II) obtained by adding a polybasic acid anhydride (a-5) to the hydroxy group of the unsaturated group-containing copolymer (A2-I) having the hydroxy group. A copolymer (A2) containing at least one selected from the group consisting of:
The carboxy group-containing copolymer (P2) is
Consisting of a structural unit derived from a polymerizable monomer (a-1A) having a bridged cyclic hydrocarbon group having 10 to 20 carbon atoms and a structural unit derived from a polymerizable monomer (a-1B) represented by the following chemical formula (1) At least one selected from the group;
A structural unit derived from a fluorine-containing (meth) acrylate (a-2) represented by the following chemical formula (2),
A copolymer containing a structural unit derived from an unsaturated carboxylic acid (a-4),
A copolymer having an acid value of 20 KOHmg / g or more.

(X and X ′ in the formula (1) each independently represent a hydrogen atom, a linear or branched hydrocarbon group having 1 to 4 carbon atoms, and R 1 and R 2 each independently. A hydrogen atom, a carboxy group, or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and may have a cyclic structure connecting R1 and R2.)

(In the formula (2), R3 represents a hydrogen atom or a methyl group, L represents —O—, —O—CH 2 —CH (OH) —CH 2 —, —O—NH—C (═O) —CH. 2 --CH 2-, each Z independently represents a hydrogen atom, a fluorine atom, a CF 3 group, a C 2 F 5 group, a C 3 F 7 group or a hydroxy group, and n is 0 to It is an integer of 12. However, at least three fluorine atoms are included in the formula (2).
The copolymer according to claim 1 or 2, which has a refractive index of less than 1.50.
The copolymer according to claim 1 or 3, wherein the epoxy group-containing copolymer (P1) has a fluorine equivalent of 100 g / mol or less.
The copolymer according to claim 2 or 3, wherein the carboxy group-containing copolymer (P2) has a fluorine equivalent of 100 g / mol or less.
The polymerizable monomer (a-1A) having a bridged cyclic hydrocarbon group having 10 to 20 carbon atoms is dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, isobornyl (meth) acrylate, and adamantyl. The copolymer (A) according to any one of claims 1 to 5, which contains at least one selected from the group consisting of (meth) acrylates.
A resin composition containing the copolymer according to any one of claims 1 to 6 and a solvent (B).
The resin composition according to claim 7, which further contains a reactive diluent (C).
Further, a photopolymerization initiator (D)
The resin composition according to claim 7, which comprises:
Contains a colorant (E),
The resin composition according to any one of claims 7 to 9, wherein the colorant (E) is at least one selected from the group consisting of dyes and pigments.
A resist comprising a cured product of the resin composition according to claim 9.