WO2020044677A1

WO2020044677A1 - Photosensitive resin composition, black column spacer and image display device

Info

Publication number: WO2020044677A1
Application number: PCT/JP2019/020494
Authority: WO
Inventors: 健宏木下; 正義柳
Original assignee: 昭和電工株式会社
Priority date: 2018-08-30
Filing date: 2019-05-23
Publication date: 2020-03-05
Also published as: TW202020559A; JP2021192068A

Abstract

Provided is a photosensitive resin composition comprising: a polymer (A) which contains structural units derived from a difunctional epoxy resin having a biphenyl skeleton, structural units derived from an unsaturated monobasic acid or an unsaturated dibasic acid monoester, and structural units derived from a polybasic acid anhydride; a solvent (B); and a photopolymerization initiator (C).

Description

Photosensitive resin composition, black column spacer, and image display device

<< The present invention relates to a photosensitive resin composition, a black column spacer, and an image display device.

(2) In image display devices such as liquid crystal display devices and organic EL display devices, spacers are used to keep the distance (cell gap) between two substrates constant. In recent years, various methods for forming a spacer from a photosensitive resin composition have been proposed. In this method, a photosensitive resin composition is applied on a substrate, a resin layer is formed, the resin layer is exposed through a predetermined mask, and then developed to form a columnar spacer or the like. According to this method, the spacer can be formed only in a predetermined portion other than the pixel display portion. Further, it has been proposed to form a black column spacer having a light-shielding property by using a photosensitive resin composition to which a light-shielding agent such as an organic black pigment is added (see Patent Documents 1 and 2).

In particular, high dimensional accuracy is required for the height of the black column spacer. In an image display device such as a liquid crystal display device, a substrate such as a TFT substrate in which elements are formed on the substrate is often used. When such a substrate is used, it may be necessary to form a black column spacer on an element formed on the substrate or on a portion of the substrate that is paired with the element on which the element is formed, facing the element. In such a case, it is necessary to change the height of the black column spacer between the place where the element is formed and the other places in consideration of the height of the element. By performing exposure through a halftone mask, the amount of exposure can be changed according to the location where the black column spacer is formed, and black column spacers having different heights can be formed at once.

JP 2015-191234 A JP-A-2014-146029

However, since the photosensitive resin composition for forming the black column spacer has a high optical density (OD), light cannot reach the lower portion of the resin layer in the exposure step, and thus hardening hardly proceeds. Therefore, in the related art, patterning is performed by performing exposure and development to form a step of the black column spacer, and then thermosetting in a subsequent post-baking step. In this case, the step forming margin of the black column spacer becomes very narrow, and there is a problem that the height of each step cannot be maintained uniformly (obtain an excellent developing margin) over the entire surface of the substrate. In addition, since the lower part of the resin layer is mainly cured by thermal curing, there is a problem that necessary chemical resistance cannot be sufficiently obtained. Furthermore, when an organic black pigment is used as a light-shielding agent, compared to a case where an inorganic black pigment such as carbon black is used, for a solvent used in a subsequent manufacturing process, metal ions and an organic black pigment contained in a spacer pattern are used. There is a problem of solvent resistance that elution occurs easily. Therefore, there is a problem that the reliability of the black column spacer in contact with the liquid crystal is reduced.

The present invention has been made to solve the above-described problems, and has an object to provide a photosensitive resin composition having excellent colorant dispersibility, development margin, solvent resistance and elastic recovery. I do.

That is, the present invention is represented by the following [1] to [17].
[1] A polymer containing a structural unit derived from a bifunctional epoxy resin having a biphenyl skeleton, a structural unit derived from an unsaturated monobasic acid or an unsaturated dibasic acid monoester, and a structural unit derived from a polybasic anhydride ( A photosensitive resin composition containing A), a solvent (B), and a photopolymerization initiator (C).
[2] The photosensitive resin composition according to [1], wherein the polymer (A) further contains a structural unit derived from a dibasic acid.
[3] The photosensitive resin composition according to [1] or [2], wherein the polymer (A) further contains a structural unit derived from a saturated monobasic acid.
[4] The polymer (A) according to any of [1] to [3], wherein the polymer (A) is obtained by adding an epoxy group-containing unsaturated compound to at least a part of the carboxy groups in the structural unit derived from the polybasic acid anhydride. The photosensitive resin composition according to any one of the above.
[5] The polymer according to any one of [1] to [4], wherein the polymer (A) is obtained by adding a bifunctional epoxy resin to at least a part of the carboxy groups in the structural unit derived from the polybasic acid anhydride. 3. The photosensitive resin composition according to item 1.
[6] The polymer (A) is composed of 30 to 80% by mass of a structural unit derived from the bifunctional epoxy resin having the biphenyl skeleton and a structural unit derived from the unsaturated monobasic acid or the unsaturated dibasic acid monoester. The photosensitive resin composition according to [1], comprising 10 to 40% by mass and 10 to 40% by mass of a structural unit derived from the polybasic acid anhydride.
[7] The polymer (A) is composed of 30 to 80% by mass of a structural unit derived from the bifunctional epoxy resin having the biphenyl skeleton and a structural unit derived from the unsaturated monobasic acid or the unsaturated dibasic acid monoester. The photosensitive composition according to [2], comprising 5 to 40% by mass, 5 to 40% by mass of the structural unit derived from the polybasic anhydride, and more than 0 to 20% by mass of the structural unit derived from the dibasic acid. Resin composition.
[8] The polymer (A) comprises 30 to 80% by mass of a structural unit derived from the bifunctional epoxy resin having the biphenyl skeleton and a structural unit derived from the unsaturated monobasic acid or the unsaturated dibasic acid monoester. The photosensitive material according to [3], comprising 5 to 40% by mass, 5 to 40% by mass of the structural unit derived from the polybasic acid anhydride, and more than 0% to 20% by mass of the structural unit derived from the saturated monobasic acid. Resin composition.
[9] The photosensitive resin composition according to [4], wherein an addition amount of the epoxy group-containing unsaturated compound is more than 0% by mass to 10% by mass with respect to the polymer (A).
[10] The photosensitive resin composition according to any one of [1] to [9], further comprising a reactive diluent (D).
[11] The polymer (A) is 1 to 20% by mass, the solvent (B) is 50 to 94% by mass, the photopolymerization initiator (C) is 0.01 to 5% by mass, and the reactive diluent is used. The photosensitive resin composition according to [10], containing 1 to 20% by mass of (D).
[12] The photosensitive resin composition according to [10], further comprising a coloring agent (E).
[13] The photosensitive resin composition according to [12], wherein the colorant (E) contains an organic black pigment.
[14] The photosensitive resin composition according to [13], wherein the colorant (E) further contains an inorganic black pigment.
[15] The polymer (A) is 1 to 20% by mass, the solvent (B) is 50 to 94% by mass, the photopolymerization initiator (C) is 0.01 to 5% by mass, and the reactive diluent is The photosensitive resin composition according to any one of [12] to [14], which contains 1 to 20% by mass of (D) and 3 to 30% by mass of the colorant (E) and is used for forming a black column spacer. .

{16} A black column spacer obtained by curing the photosensitive resin composition according to [15].

画像 An image display device comprising the black column spacer according to [17] or [16].

According to the present invention, a photosensitive resin composition having excellent colorant dispersibility, development margin, solvent resistance and elastic recovery can be provided. The photosensitive resin composition of the present invention can be used for forming a color filter, a photo spacer, a black matrix, a black column spacer, etc., and can be particularly suitably used for forming a black column spacer.

<Photosensitive resin composition>
Hereinafter, the photosensitive resin composition of the present invention will be described in detail.
The photosensitive resin composition of the present invention has a constitutional unit derived from a bifunctional epoxy resin having a biphenyl skeleton and a constitutional unit derived from an unsaturated monobasic acid or an unsaturated dibasic acid monoester and a constitution derived from a polybasic anhydride. It contains a polymer (A) containing a unit, a solvent (B), and a photopolymerization initiator (C).

In this specification, “(meth) acryloyloxy group” means at least one selected from acryloyloxy group and methacryloyloxy group, and “(meth) acrylic acid” means acrylic acid and methacrylic acid. "(Meth) acrylate" means at least one selected from acrylates and methacrylates. Further, “bifunctional” of a bifunctional epoxy resin means having two epoxy groups.

<Polymer (A)>
The polymer (A) used in the present invention comprises a structural unit derived from a bifunctional epoxy resin having a biphenyl skeleton, a structural unit derived from an unsaturated monobasic acid or a monoester derived from an unsaturated dibasic acid, and a polybasic acid anhydride. At least a structural unit.

The polymer (A) is obtained by reacting a bifunctional epoxy resin having a biphenyl skeleton reacted with an unsaturated monobasic acid or unsaturated dibasic acid monoester with a polybasic acid anhydride in the presence of a reaction catalyst. It can be manufactured by the following.

The bifunctional epoxy resin having a biphenyl skeleton is not particularly limited as long as it has a biphenyl skeleton in the molecule and has two epoxy groups. Examples of the biphenyl skeleton include those represented by the following formula.

ＲIn the above formula, R represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and * represents a divalent linking group.

Specific examples of the bifunctional epoxy resin having a biphenyl skeleton include YX4000 (in the following formula, R ′ is CH ₃ ) and YX4000K (in the following formula, R ′ is CH ₃ ) manufactured by Mitsubishi Chemical Corporation. YX4000H (in the following formula, R 'is CH ₃ ), and YL6121HA (in the following formula, a mixture of a compound in which R' is H and a compound in which R 'is CH ₃ ).

An unsaturated monobasic acid or unsaturated dibasic acid monoester is added to the epoxy group of the bifunctional epoxy resin having a biphenyl skeleton to introduce an unsaturated group into the polymer (A).
Examples of the unsaturated monobasic acid include (meth) acrylic acid, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, α-bromo (meth) acrylic acid, β -Unsaturated carboxylic acids such as furyl (meth) acrylic acid, crotonic acid, propiolic acid, cinnamic acid and α-cyanocinnamic acid. Examples of the unsaturated dibasic acid monoester include monomethyl maleate, monoethyl maleate, monoisopropyl maleate, monomethyl fumarate, monoethyl itaconate, and the like. These unsaturated monobasic acid or unsaturated dibasic acid monoesters may be used alone or in combination of two or more. Among these, (meth) acrylic acid is preferable from the viewpoint of availability and reactivity.

The polybasic acid anhydride is an epoxy group of the bifunctional epoxy resin having a biphenyl skeleton by an addition reaction between the unsaturated monobasic acid or unsaturated dibasic acid monoester and the bifunctional epoxy resin having a biphenyl skeleton. Ring opening is added to the hydroxy group generated by ring opening to introduce a carboxy group into the polymer (A).
Polybasic acid anhydrides include maleic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, succinic anhydride, butanetetracarboxylic anhydride, pentanetetracarboxylic anhydride, hexane Examples thereof include tetracarboxylic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic dianhydride, biphenyltetracarboxylic dianhydride, and cyclohexanetricarboxylic anhydride. Among these, biphenyltetracarboxylic dianhydride, tetrahydrophthalic anhydride and succinic anhydride are preferable from the viewpoint of availability and reactivity.

The polymer (A) may further contain a structural unit derived from a dibasic acid. The polymer (A) can be made high molecular weight by a polycondensation reaction between the carboxy group of the dibasic acid and the epoxy group of the bifunctional epoxy resin having the biphenyl skeleton. Although it does not specifically limit as a dibasic acid, Adipic acid, itaconic acid, succinic acid, oxalic acid, malonic acid, phthalic acid, fumaric acid, maleic acid, glutaric acid, tartaric acid, glutamic acid, sebacic acid, etc. are mentioned. The dibasic acids may be used alone or in combination of two or more. Among these, adipic acid and itaconic acid are preferred from the viewpoint of reactivity. When the polymer (A) further contains a structural unit derived from a dibasic acid, the flexibility is improved.

The polymer (A) may further contain not only a constitutional unit derived from an unsaturated monobasic acid or an unsaturated dibasic acid monoester but also a constitutional unit derived from a saturated monobasic acid, if necessary. The saturated monobasic acid can be introduced into the polymer (A) by adding the unsaturated monobasic acid or unsaturated dibasic acid monoester to the epoxy group of the bifunctional epoxy resin having the biphenyl skeleton. it can. Although it does not specifically limit as a saturated monobasic acid, Formic acid, acetic acid, propionic acid, butyric acid, lauric acid, tridecylic acid, palmitic acid, stearic acid, etc. are mentioned. The saturated monobasic acids may be used alone or in combination of two or more. Among these, acetic acid and propionic acid are preferred from the viewpoint of boiling point and reactivity. When the polymer (A) further contains a structural unit derived from a saturated monobasic acid, flexibility is improved.

The polymer (A) further containing a constitutional unit derived from a dibasic acid and / or a constitutional unit derived from a saturated monobasic acid can be used in combination with a bifunctional epoxy resin having a biphenyl skeleton and optionally a dibasic acid in the presence of a polymerization catalyst. And a polycondensation reaction with an unsaturated monobasic acid or an unsaturated dibasic acid monoester, a polybasic acid anhydride, and a optionally used saturated monobasic acid in the presence of a reaction catalyst. Can be manufactured. The order of the polycondensation reaction and the addition reaction may be appropriately changed.

The polymer (A) contains 30 to 80% by mass of a structural unit derived from a bifunctional epoxy resin having a biphenyl skeleton, and 10 to 40% by mass of a structural unit derived from an unsaturated monobasic acid or an unsaturated dibasic acid monoester. And a structural unit derived from a polybasic acid anhydride in an amount of 10 to 40% by mass, a structural unit derived from a bifunctional epoxy resin having a biphenyl skeleton in an amount of 40 to 70% by mass, and an unsaturated monobasic acid-derived or unsaturated unit. More preferably, it contains 15 to 30% by mass of a structural unit derived from a dibasic acid monoester and 15 to 30% by mass of a structural unit derived from a polybasic acid anhydride. The mass ratio of the structural unit derived from the bifunctional epoxy resin having the biphenyl skeleton, the structural unit derived from the unsaturated monobasic acid or the unsaturated dibasic acid monoester, and the structural unit derived from the polybasic anhydride is within the above range. It is preferable to balance the elastic recovery rate, developability, and solvent resistance. Here, the molar ratio of the structural unit derived from the unsaturated monobasic acid or the unsaturated dibasic acid monoester to the structural unit derived from the bifunctional epoxy resin having a biphenyl skeleton in the polymer (A) is 1.8. The molar ratio of the structural units derived from polybasic acid anhydride is preferably from 0.1 to 1.3, more preferably from 0.2 to 1.2. The ratio of these constituent units can be calculated from the amount of raw materials charged when producing the polymer (A), in addition to being calculated by NMR analysis.

In the polymer (A) further containing a structural unit derived from a dibasic acid, 30 to 80% by mass of a structural unit derived from a bifunctional epoxy resin having a biphenyl skeleton is combined with an unsaturated monobasic acid-derived or unsaturated dibasic acid monoester. It preferably contains 5 to 40% by mass of a structural unit derived from a polybasic acid anhydride, 5 to 40% by mass of a structural unit derived from a polybasic acid anhydride, and more than 0 to 20% by mass of a structural unit derived from a dibasic acid. A structural unit derived from a bifunctional epoxy resin having a skeleton of 40 to 70% by mass, a structural unit derived from an unsaturated monobasic acid or an unsaturated dibasic acid monoester from 10 to 40% by mass, and a polybasic acid anhydride derived More preferably, it contains 10 to 40% by mass of the structural unit and more than 0% to 20% by mass of the structural unit derived from a dibasic acid, and the structural unit 40 to 6 derived from a bifunctional epoxy resin having a biphenyl skeleton. %, A structural unit derived from an unsaturated monobasic acid or an unsaturated dibasic acid monoester, 10 to 25% by mass, a structural unit derived from a polybasic acid anhydride, 15 to 30% by mass, and a structural unit derived from a dibasic acid. More preferably, it contains 5 to 15% by mass of a structural unit. Here, the molar ratio of the structural unit derived from the unsaturated monobasic acid or unsaturated dibasic acid monoester to the structural unit derived from the bifunctional epoxy resin having a biphenyl skeleton in the polymer (A) is 0.3. It is preferably from 1.6 to 1.6, more preferably from 0.5 to 1.0, and the molar ratio of the structural unit derived from a dibasic acid is preferably from 0.1 to 0.8, and from 0.1 to 0.8. It is more preferably from 15 to 0.7, and the molar ratio of the structural unit derived from polybasic acid anhydride is preferably from 0.1 to 1.3, more preferably from 0.2 to 1.2. preferable.

In the polymer (A) further containing a structural unit derived from a saturated monobasic acid, 30 to 80% by mass of a structural unit derived from a bifunctional epoxy resin having a biphenyl skeleton and an unsaturated monobasic acid-derived or unsaturated dibasic acid It preferably contains 5 to 40% by mass of a structural unit derived from an ester, 5 to 40% by mass of a structural unit derived from a polybasic anhydride, and more than 0 to 20% by mass of a structural unit derived from a saturated monobasic acid. A structural unit derived from a bifunctional epoxy resin having a biphenyl skeleton, from 40 to 70% by mass, a structural unit derived from an unsaturated monobasic acid or an unsaturated dibasic acid monoester from 10 to 40% by mass, and a polybasic anhydride. More preferably, the composition contains 10 to 40% by mass of a structural unit derived from a bifunctional epoxy resin having a biphenyl skeleton, and more than 0% to 20% by mass of a structural unit derived from a saturated monobasic acid. 40 to 64% by mass, 10 to 25% by mass of a structural unit derived from an unsaturated monobasic acid or an unsaturated dibasic acid monoester, 15 to 30% by mass of a structural unit derived from a polybasic anhydride, More preferably, it contains 5 to 15% by mass of a structural unit derived from a monobasic acid. Here, a structural unit derived from an unsaturated monobasic acid or an unsaturated dibasic acid monoester and a structural unit derived from a saturated monobasic acid with respect to the structural unit derived from a bifunctional epoxy resin having a biphenyl skeleton in the polymer (A). The total molar ratio of the structural units is preferably 1.8 to 2.0, and the molar ratio of the structural units derived from polybasic acid anhydride is preferably 0.1 to 1.3, and 0.2 More preferably, it is ～ 1.2.

In the polymer (A) further containing a constitutional unit derived from a dibasic acid and a constitutional unit derived from a saturated monobasic acid, 30 to 80% by mass of a constitutional unit derived from a bifunctional epoxy resin having a biphenyl skeleton is added to the unsaturated monobasic acid. 5 to 40% by weight of a structural unit derived from a monobasic or unsaturated dibasic acid monoester, 5 to 40% by weight of a structural unit derived from a polybasic anhydride, and more than 0 to 20% by weight of a structural unit derived from a dibasic acid % And more than 0% by mass to 20% by mass of a structural unit derived from a saturated monobasic acid, and 40 to 70% by mass of a structural unit derived from a bifunctional epoxy resin having a biphenyl skeleton, and an unsaturated monobasic acid. 10 to 40% by mass of a structural unit derived from a monobasic or unsaturated dibasic acid monoester, 10 to 40% by mass of a structural unit derived from a polybasic anhydride, and more than 0 to 20% by mass of a structural unit derived from a dibasic acid % And saturation More preferably, it contains more than 0 to 20% by mass of a structural unit derived from a basic acid, and 40 to 64% by mass of a structural unit derived from a bifunctional epoxy resin having a biphenyl skeleton and an unsaturated monobasic acid-derived or unsaturated unit. 10 to 25% by mass of a structural unit derived from a dibasic acid monoester, 15 to 30% by mass of a structural unit derived from a polybasic anhydride, 5 to 15% by mass of a structural unit derived from a dibasic acid, and a saturated monobasic acid More preferably, it contains 5 to 15% by mass of a structural unit derived therefrom. Here, a structural unit derived from an unsaturated monobasic acid or an unsaturated dibasic acid monoester and a structural unit derived from a saturated monobasic acid are used with respect to the structural unit derived from a bifunctional epoxy resin having a biphenyl skeleton in the polymer (A). The total molar ratio of the structural units is preferably from 0.3 to 1.6, more preferably from 0.5 to 1.0, and the molar ratio of the dibasic acid-derived structural units is from 0.1 to 1.0. It is preferably 0.8, more preferably 0.15 to 0.7, and the molar ratio of the structural unit derived from polybasic acid anhydride is preferably 0.1 to 1.3. It is more preferable that the ratio be from 2 to 1.2.

(4) An epoxy group-containing unsaturated compound may be added to at least a part of the carboxy group generated from the polybasic acid anhydride in the above addition reaction. Examples of the epoxy group-containing unsaturated compound include glycidyl (meth) acrylate, 2-glycidyloxyethyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate having an alicyclic epoxy, and a lactone adduct thereof ( For example, Cyclomer (registered trademark) A200, M100 manufactured by Daicel Chemical Industries, Ltd., mono (meth) acrylate of 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, dicyclopentenyl Epoxidized (meth) acrylate, epoxidized dicyclopentenyloxyethyl (meth) acrylate and the like can be mentioned. These unsaturated compounds containing an epoxy group may be used alone or in combination of two or more. Among these, glycidyl (meth) acrylate is preferred from the viewpoint of availability and reactivity.

The addition amount of the epoxy group-containing unsaturated compound is preferably more than 0% by mass to 10% by mass, more preferably more than 0% by mass to 5% by mass, based on the polymer (A). It is preferable that the addition amount of the epoxy group-containing unsaturated compound exceeds 0% by mass because sensitivity can be increased. On the other hand, when the addition amount of the epoxy group-containing unsaturated compound is 10% by mass or less, the elastic recovery rate and the developability are preferably maintained.
The molar ratio of the added epoxy group-containing unsaturated compound to the structural unit derived from the bifunctional epoxy resin having a biphenyl skeleton in the polymer (A) is preferably 0.05 to 0.3. The molar ratio of the epoxy group-containing unsaturated compound added to the structural unit derived from the polybasic acid anhydride of the polymer (A) is preferably 0.1 to 0.5.

(4) An epoxy resin may be added to at least a part of the carboxy groups generated from the polybasic acid anhydride in the above reaction. Examples of the epoxy resin include, but are not particularly limited to, a novolak epoxy resin, a bisphenol epoxy resin, and a biphenyl epoxy resin. From the viewpoint of preventing an increase in molecular weight, it is preferable to use a bifunctional epoxy resin. The added amount of the epoxy resin is preferably more than 0% by mass to 20% by mass based on the polymer (A). The molar ratio of the epoxy resin added to the structural unit derived from the bifunctional epoxy resin having a biphenyl skeleton in the polymer (A) is preferably 0.05 to 0.3. The epoxy resin to be added preferably has a weight average molecular weight of 150 to 350. When a bifunctional epoxy resin having a biphenyl skeleton is used as the epoxy resin, when calculating the ratio of each structural unit, the epoxy resin used for the main skeleton of the polymer (A) is distinguished from the epoxy resin to be added later. Without considering them.

The conditions of the addition reaction and the polycondensation reaction for obtaining the polymer (A) or the precursor of the polymer (A) used in the present invention may be appropriately set according to a conventional method. In the polycondensation reaction, for example, each raw material and a polymerization catalyst are added to a solvent, preferably in an atmosphere having an oxygen gas concentration of 5 to 7% by volume, preferably at 50 to 150 ° C, more preferably at 60 to 140 ° C for 1 to 1%. All you have to do is 12 hours.
The addition reaction is performed by adding each raw material and an addition reaction catalyst to a solvent, preferably in an atmosphere having an oxygen gas concentration of 5 to 7% by volume, preferably at 50 to 150 ° C, more preferably at 80 to 130 ° C for 3 to 12 hours. Just do it. In these reactions, there is no problem even if the solvent used for obtaining the precursor of the polymer (A) is directly contained as a solvent used in the next reaction.

溶媒 The solvent that can be used in the above-mentioned polycondensation reaction and addition reaction is not particularly limited, and a known solvent can be appropriately used. Specific examples of the solvent include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, and triethylene glycol. Glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene Glycol monomethyl ether, tri (Poly) alkylene glycol monoalkyl ethers such as propylene glycol monoethyl ether; (poly) alkylene glycol monoalkyls such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate Ether acetate; other ether compounds such as diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, and tetrahydrofuran; ketone compounds such as methyl ethyl ketone, cyclohexanone, 2-heptanone and 3-heptanone; methyl 2-hydroxypropionate and 2-hydroxypropion Ethyl acid, 2 Methyl hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethoxyacetic acid Ethyl, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutyrate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, ethyl acetate, n-butyl acetate, n-propyl acetate I-propyl acetate, n-butyl acetate, i-butyl acetate, n-amyl acetate, i-amyl acetate, n-butyl propionate, ethyl butyrate, n-propyl butyrate, i-propyl butyrate, n-butyl butyrate, Methyl pyruvate, ethyl pyruvate, n-propyl pyruvate, aceto Ester compounds such as methyl acetate, ethyl acetoacetate and ethyl 2-oxobutyrate; aromatic hydrocarbon compounds such as toluene and xylene; carboxylic acids such as N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide Amide compounds and the like can be mentioned. These solvents may be used alone or in combination of two or more.

Among them, (poly) alkylene glycol monoalkyl ethers such as propylene glycol monomethyl ether and (poly) alkylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate, that is, glycol ether solvents are preferable.

The amount of the solvent used is not particularly limited, but generally 10 to 300 parts by mass, preferably 100 to 300 parts by mass, based on 100 parts by mass of the raw materials of the polymer (A) or the precursor of the polymer (A). Is from 20 to 100 parts by mass. When the amount of the solvent used is 300 parts by mass or less, it is preferable because the reaction can be performed in an appropriate time and the viscosity of the polymer (A) can be controlled in an appropriate range. On the other hand, when the amount of the solvent used is 10 parts by mass or more, the reaction can be stably performed, which is preferable. Further, coloring and gelling of the polymer (A) can also be prevented.

種類 The types of the polymerization catalyst and the addition reaction catalyst used in the above-mentioned polymerization reaction and addition reaction are not particularly limited, and are selected as necessary. Examples of these catalysts include tertiary amines such as triethylamine, quaternary ammonium salts such as triethylbenzylammonium chloride, phosphorus compounds such as triphenylphosphine, chromium chelate compounds and the like. These catalysts may be used alone or in combination of two or more. The amount of the catalyst to be used is not particularly limited, but is generally 0.01 to 5 parts by mass based on 100 parts by mass of each raw material of the polymer (A) or the precursor of the polymer (A). , Preferably 0.05 to 2 parts by mass, more preferably 0.1 to 1 part by mass.

When using an unsaturated group-containing compound (unsaturated monobasic acid or unsaturated dibasic acid monoester, epoxy group-containing unsaturated compound) as a raw material, it is preferable to add a polymerization inhibitor to prevent gelation. . The type of the polymerization inhibitor is not particularly limited, and is selected as needed. Examples of the polymerization inhibitor include hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, butylhydroxytoluene, and the like. These polymerization inhibitors may be used alone or in combination of two or more. Although the amount of the polymerization inhibitor used is not particularly limited, it is generally 0.01 to 5 parts by mass based on 100 parts by mass of each raw material of the polymer (A) or the precursor of the polymer (A). Parts by mass, preferably 0.02 to 2 parts by mass, more preferably 0.04 to 0.5 parts by mass.

重合 The polymer (A) used in the present invention has a weight average molecular weight of preferably from 1,000 to 50,000, more preferably from 3,000 to 40,000, as calculated as polystyrene by gel permeation chromatography (GPC). It is preferable that the weight average molecular weight of the polymer (A) is 1,000 or more, since pattern chipping does not occur after alkali development. On the other hand, when the weight average molecular weight of the polymer (A) is 50,000 or less, the development time becomes an appropriate time and it is practical in use, and thus it is preferable. In particular, the weight average molecular weight of the polymer (A) obtained by adding a bifunctional epoxy resin to the precursor of the polymer (A) to increase the molecular weight is preferably from 3,000 to 40,000.

The acid value (JIS K6901 5.3) of the polymer (A) used in the present invention is not limited as long as the desired effect of the present invention is exhibited, but is usually 20 to 300 KOH mg / g, preferably 30 to 200 KOH mg / g. is there. It is preferable that the acid value of the polymer (A) is 20 KOHmg / g or more, since the developability becomes good. On the other hand, when the acid value of the polymer (A) is 300 KOH mg / g or less, the exposed portion (photocured portion) is less likely to be dissolved in the alkali developing solution, so that it is preferable.

The unsaturated group equivalent of the polymer (A) used in the present invention is not limited as long as the desired effect of the present invention is obtained, but is usually 100 to 4000 g / mol, preferably 200 to 2000 g / mol. Preferably it is 250 to 500 g / mol. When the unsaturated group equivalent of the polymer (A) is at least 100 g / mol, it is effective in enhancing the properties of the coating film and the alkali developability, so that it is preferable. On the other hand, when the unsaturated group equivalent of the polymer (A) is 4000 g / mol or less, it is effective in further increasing the sensitivity, and thus it is preferable. Note that the unsaturated group equivalent is the mass of the polymer (A) per mole of the unsaturated bond (ethylenic carbon-carbon double bond) in the polymer (A). The unsaturated group equivalent can be determined by dividing the mass of the polymer (A) by the number of unsaturated groups in the polymer (A) (g / mol). In the present specification, the unsaturated group equivalent is a theoretical value calculated from a charged amount of a raw material used for introducing an unsaturated group.

<Solvent (B)>
The solvent (B) used in the photosensitive resin composition of the present invention is not particularly limited as long as it is an inert solvent that can dissolve the polymer (A) and does not react with the polymer (A). You can choose. The solvent (B) preferably has compatibility with the reactive diluent described below. As the solvent (B), the same solvent as used in producing the polymer (A) can be used. As the solvent (B), (poly) alkylene glycol monoalkyl ether such as propylene glycol monomethyl ether and (poly) alkylene glycol monoalkyl ether acetate such as propylene glycol monomethyl ether acetate are preferable.

The solvent (B) can be used to isolate the desired polymer (A) from the solution of the polymer (A) after the reaction, and to appropriately add the isolated polymer (A). However, it is not always necessary to isolate the target polymer (A) from the polymer (A) solution. The solvent contained at the end of the reaction can be used as the solvent (B) without separating the solvent contained in the polymer (A) solution. If necessary, another solvent may be added to the polymer (A) solution. Further, a solvent contained in another component used when preparing the photosensitive resin composition may be used as it is as the solvent (B).

<Photopolymerization initiator (C)>
The photopolymerization initiator (C) is not particularly limited. Examples of the photopolymerization initiator (C) include 1,2-octanedione, 1- [4- (phenylthio)-, 2- (o-benzoyloxime)], ethanone, and 1- [9-ethyl-6- Oxime esters such as (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (o-acetyloxime); benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether and benzoin butyl ether; acetophenone; 2,2-dimethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 4- (1-t-butyldioxy-1-methylethyl) acetophenone, 2-methyl-1- [4- (methylthio) phenyl] -2 -Morpholino-propan-1-one, 2-benzyl-2-dimethylamino-1- (4-mo Acetophenones such as (holinophenyl) butanone-1; anthraquinones such as 2-methylanthraquinone, 2-amylanthraquinone, 2-t-butylanthraquinone and 1-chloroanthraquinone; xanthone, thioxanthone, 2,4-dimethylthioxanthone and 2,4 Thioxanthones such as -diisopropylthioxanthone and 2-chlorothioxanthone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenone, 4- (1-t-butyldioxy-1-methylethyl) benzophenone, 3,3 ', 4 Benzophenones such as 4′-tetrakis (t-butyldioxycarbonyl) benzophenone; acylphosphine oxides; These photopolymerization initiators (C) may be used alone or in combination of two or more.

As the photopolymerization initiator (C), among the above compounds, 2-methyl-1- (4) is particularly preferred because of its high sensitivity to i-line (365 nm) and little yellowing of the cured product during curing and baking. Acetophenones such as -methylthiophenyl) -2-morpholinopropan-1-one, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (o-benzoyloxime)], ethanone, 1- It is preferable to use an oxime ester type such as [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl]-, 1- (o-acetyloxime). These photopolymerization initiators may be used alone or in combination of two or more, depending on, for example, the intended sensitivity.

Preferred amounts of the polymer (A), the solvent (B) and the photopolymerization initiator (C) in the photosensitive resin composition of the present invention are as follows.
The compounding amount of the polymer (A) is preferably from 1 to 20% by mass, more preferably from 5 to 15% by mass, based on the whole photosensitive resin composition. When the blending amount of the polymer (A) is 1% by mass or more, it is preferable because it has good photocurability. On the other hand, when the blending amount of the polymer (A) is 20% by mass or less, it is preferable because it has good coatability.
The compounding amount of the solvent (B) is preferably from 50 to 94% by mass, more preferably from 60 to 87.9% by mass, based on the entire photosensitive resin composition. It is preferable that the amount of the solvent (B) is 50% by mass or more, since good coating properties are obtained. On the other hand, when the blending amount of the solvent (B) is 94% by mass or less, it is preferable because the coating film can have a sufficient film thickness.
The compounding amount of the photopolymerization initiator (C) is preferably from 0.01 to 5% by mass, more preferably from 0.1 to 2% by mass, based on the whole photosensitive resin composition. When the blending amount of the photopolymerization initiator (C) is 0.01% by mass or more, it is preferable since the resist can have curability. On the other hand, when the blending amount of the photopolymerization initiator (C) is 5% by mass or less, a residue after development hardly occurs, which is preferable.

<Reactive diluent (D)>
The photosensitive resin composition of the present invention can further contain a reactive diluent (D). By containing the reactive diluent (D), the workability is improved by adjusting the viscosity of the photosensitive resin composition, and the strength of the cured product of the photosensitive resin composition and / or the adhesion to the substrate are improved. Can be improved.

As the reactive diluent (D), a compound having at least one polymerizable ethylenically unsaturated group as a polymerizable functional group in a molecule is used, and it is particularly preferable to use a compound having a plurality of polymerizable functional groups. . Specifically, as the reactive diluent (D), the following monofunctional monomers and / or polyfunctional monomers can be used.

Monofunctional monomers include (meth) acrylamide, methylol (meth) acrylamide, methoxymethyl (meth) acrylamide, ethoxymethyl (meth) acrylamide, propoxymethyl (meth) acrylamide, butoxymethoxymethyl (meth) acrylamide, methyl (meth) Acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate , 2-phenoxy-2-hydroxypropyl (meth) acrylate, 2- (meth) acryloyloxy-2-hydroxypropyl phthalate, glycerin mono (meth) acrylate, tetra Drofurfuryl (meth) acrylate, glycidyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, half (meth) of phthalic acid derivative (Meth) acrylates such as acrylate; aromatic vinyl compounds such as styrene, α-methylstyrene, α-chloromethylstyrene, and vinyltoluene; and carboxylic acid esters such as vinyl acetate and vinyl propionate. These monofunctional monomers may be used alone or in combination of two or more.

Examples of the polyfunctional monomer include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, and butylene glycol di ( (Meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexane glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, glycerin di (meth) acrylate, pentaerythritol di (meth) acrylate, Pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 2, -Bis (4- (meth) acryloxydiethoxyphenyl) propane, 2,2-bis (4- (meth) acryloxypolyethoxyphenyl) propane, 2-hydroxy-3- (meth) acryloyloxypropyl (meth) Acrylate, ethylene glycol diglycidyl ether di (meth) acrylate, diethylene glycol diglycidyl ether di (meth) acrylate, phthalic acid diglycidyl ester di (meth) acrylate, glycerin triacrylate, glycerin polyglycidyl ether poly (meth) acrylate, urethane ( Reaction of (meth) acrylate (ie, tolylene diisocyanate), trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, etc. with 2-vidroxyethyl (meth) acrylate (Meth) acrylates such as tri (meth) acrylate of tris (hydroxyethyl) isocyanurate; aromatic vinyl compounds such as divinylbenzene, diallyl phthalate and diallylbenzene phosphonate; dicarboxylic acid esters such as divinyl adipate; Examples include allyl cyanurate, methylene bis (meth) acrylamide, (meth) acrylamide methylene ether, and condensates of polyhydric alcohol with N-methylol (meth) acrylamide. These polyfunctional monomers may be used alone or in combination of two or more.

As the reactive diluent (D), among the above monomers, any one of trimethylolpropane tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate It is preferable to include

(4) When the reactive diluent (D) is blended, the blending amount is preferably 1 to 20% by mass, more preferably 2 to 10% by mass, based on the whole photosensitive resin composition. It is preferable that the content of the reactive diluent (D) is 1% by mass or more, since it has good curability. On the other hand, when the content of the reactive diluent (D) is 20% by mass or less, it is preferable because residues after development are less likely to be generated.

<Colorant (E)>
When a colored pattern is formed by curing the photosensitive resin composition of the present invention, the photosensitive resin composition of the present invention may further contain a colorant (E).

The colorant (E) is not particularly limited, and examples thereof include dyes and pigments. The dye and the pigment may be used alone, two or more of them may be used, or the dye and the pigment may be used in combination. When the photosensitive resin composition of the present invention is cured to form a black column spacer, from the viewpoint of solubility in the solvent (B) and the alkaline developer, interaction with other components, and light-shielding properties, the photosensitive resin composition of the present invention is used. The conductive resin composition preferably contains a black pigment as the colorant (E).

Examples of the black pigment include an inorganic black pigment and an organic black pigment, and specific examples include aniline black, perylene black, titanium black, cyanine black, lignin black, lactam organic black, RGB black, and carbon black. These black pigments may be used alone or in combination of two or more. From the viewpoint of optical density, it is preferable to use an inorganic black pigment and an organic black pigment in combination, and it is more preferable to use carbon black and a lactam organic black in combination. It is also preferable to mix three types of RGB black, which is a mixture of carbon black, lactam-based organic black, Red, Green, and Blue.

The pigments usable for RGB black are not particularly limited, but C.I. I. Pigment Red 9, 97, 105, 122, 123, 144, 149, 154, 166, 168, 176, 177, 180, 192, 209, 215, 216, 224, 242, 254, 255, 264, 265, etc. Pigments; C.I. I. Green pigments such as CI Pigment Green 7, 36, 58, 59, 62; I. And blue pigments such as CI Pigment Blue 15, 15: 3, 15: 4, 15: 6, and 60. In addition, complementary colors of yellow, orange, violet and brown can also be used together. 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, Yellow pigments such as 147, 148, 150, 153, 154, 166, 173, 194, 214; I. Orange pigments such as CI Pigment Orange 13, 31, 36, 38, 40, 42, 43, 51, 55, 59, 61, 64, 65, 71, 73; I. Violet color pigments such as CI Pigment Violet 1, 19, 23, 29, 32, 36, 38; I. And brown pigments such as CI Pigment Brown 23 and 25. These pigments may be used alone or in combination of two or more depending on, for example, the color of a target pixel.

場合 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, a polymer dispersant is preferably used because of its excellent dispersion stability over time. The polymer dispersant can be arbitrarily selected, for example, a urethane dispersant, a polyethyleneimine dispersant, a polyoxyethylene alkyl ether dispersant, a polyoxyethylene glycol diester dispersant, a sorbitan aliphatic ester dispersant, Examples include aliphatic modified ester dispersants. As such a polymer dispersant, EFKA (registered trademark, manufactured by BASF Japan), Disperbyk (registered trademark, manufactured by Big Chemie), Disparon (registered trademark, manufactured by Kusumoto Kasei Co., Ltd.), SOLSPERSE (registered trademark, manufactured by Zeneca Corporation) ) May be used. The compounding amount of the dispersant may be appropriately set according to the type of the pigment or the like used.

(4) When the colorant (E) is compounded, the compounding amount is preferably 3 to 30% by mass, more preferably 5 to 20% by mass, based on the whole photosensitive resin composition. When the blending amount of the coloring agent (E) is 3% by mass or more, it is preferable since it has light-shielding properties. On the other hand, when the blending amount of the coloring agent (E) is 30% by mass or less, a residue after development hardly occurs, which is preferable.

Further, the photosensitive resin composition of the present invention may contain known additives such as a coupling agent, a leveling agent, and a thermal polymerization inhibitor as long as the effects of the present invention are not impaired. The amounts of these additives are not particularly limited as long as the effects of the present invention are not impaired.

感光 The photosensitive resin composition of the present invention can be produced by mixing the above components (A) to (E) using a known mixing device. If desired, a composition containing the polymer (A) and the solvent (B) is prepared in advance, and then the photopolymerization initiator (C), a reactive diluent (D) as an optional component, and a colorant (E) Can also be added and mixed for production.

<Black column spacer>
Next, the black column spacer will be described in detail.
The black column spacer is obtained by curing the photosensitive resin composition for forming a black column spacer containing the above components (A) to (D) and a black pigment as a coloring agent (E). Specifically, first, a photosensitive resin composition for forming a black column spacer is applied on a substrate to form a resin layer (coating film). Thereafter, the resin layer is exposed to light through a halftone mask having a predetermined pattern, and the exposed portions are light-cured. Then, the unexposed portion and the semi-exposed portion are developed with an alkali developer to form a black column spacer. Thereafter, the black column spacer is post-baked as necessary.

材質 The material of the substrate is not particularly limited, and examples thereof include 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 substrate, and an array substrate.

The method of applying the photosensitive resin composition for forming a black column spacer is not particularly limited, and examples thereof include a screen printing method, a roll coating method, a curtain coating method, a spray coating method, and a spin coating method. Further, after the photosensitive resin composition for forming a black column spacer is applied, if necessary, the solvent (B) contained in the resin layer is heated by using a heating means such as a circulation oven, an infrared heater and a hot plate. ) May be volatilized. The heating conditions are not particularly limited, and may be appropriately set according to the composition of the photosensitive resin composition for forming a black column spacer to be used. Generally, it is preferable to heat at a temperature of 50 ° C to 120 ° C for 30 seconds to 30 minutes.

The method of exposing the resin layer is not particularly limited, and examples thereof include irradiation with active energy rays such as ultraviolet rays and excimer laser light. The irradiation energy dose may be appropriately set according to the composition of the photosensitive resin composition for forming a black column spacer. For example, it is preferably 30 to 2000 mJ / cm ² , but is not limited to this range. 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, or the like can be arbitrarily selected and used.

The alkali developer used for development is not particularly limited, and examples thereof include aqueous solutions of sodium carbonate, potassium carbonate, calcium carbonate, sodium hydroxide, potassium hydroxide, and the like; aqueous solutions of amine compounds such as ethylamine, diethylamine, and dimethylethanolamine. Tetramethylammonium, 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 sulfates, hydrochlorides or p-toluenes such as p-toluenesulfonate An aqueous solution of a phenylenediamine compound is exemplified. Incidentally, an antifoaming agent, a surfactant and the like may be added to these alkali developing solutions as needed. After development with an alkali developer, it is preferable to wash with water and dry.

ポスト By post-baking the black column spacer formed by alkali development, the curing of the resin can be further promoted. The post-baking conditions are not particularly limited and can be arbitrarily selected. Heat treatment may be performed under suitable conditions according to the composition of the photosensitive resin composition for forming a black column spacer. For example, heating may be performed at a temperature of 130 ° C. to 250 ° C., preferably for 10 minutes to 4 hours, more preferably for 20 minutes to 2 hours.

ブラック The black column spacer thus produced is excellent in colorant dispersibility, solvent resistance and elastic recovery.

<Image display device>
An image display device according to the present invention is an image display device including the above-described black column spacer. Specific examples of the image display device include a liquid crystal display device and an organic EL display device. In manufacturing the image display device, there is no limitation except that the above-described black column spacer is formed, and the image display device can be manufactured according to a conventional method.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

<Measurement of physical properties>
The acid value, unsaturated group equivalent and weight average molecular weight described in the synthesis examples are values obtained by the methods described below.
(1) Acid value: An acid value of a polymer measured using a mixed indicator of bromothymol blue and phenol red according to JIS K6901 5.3.2. It means the number of mg of potassium hydroxide required to neutralize the acidic component contained in 1 g of the polymer.
(2) Unsaturated group equivalent: the mass of the polymer per mole of polymerizable unsaturated bonds, and is a calculated value calculated based on the amount of the monomer used.
(3) Weight average molecular weight (Mw): means the weight average molecular weight measured by gel permeation chromatography (GPC) under the following conditions and converted into standard polystyrene.
Column: Showdex (registered trademark) LF-804 + LF-804 (manufactured by Showa Denko KK)
Column temperature: 40 ° C
Specimen: 0.2% tetrahydrofuran solution of polymer Developing solvent: tetrahydrofuran Detector: Differential refractometer (Showdex (registered trademark) RI-71S) (manufactured by Showa Denko KK)
Flow rate: 1 mL / min

<Synthesis example 1>
In a flask equipped with a stirrer, a dropping funnel, a condenser, a thermometer and a gas introduction tube, 126.4 g of propylene glycol monomethyl ether acetate as a solvent and YX4000K 186. manufactured by Mitsubishi Chemical Corporation as a bifunctional epoxy resin having a biphenyl skeleton were used. Then, the flask was stirred while replacing the inside of the flask with a nitrogen gas / air mixed gas having an oxygen gas concentration of 5 to 7% by volume, and the temperature was raised to 120 ° C.
Next, 72.0 g of acrylic acid, 0.8 g of triphenylphosphine (catalyst) and 0.8 g of methoquinone (polymerization inhibitor) were added to the flask. Thereafter, the reaction was continued at 120 ° C. for 10 hours to obtain an epoxy acrylate having a biphenyl skeleton.
Further, 73.5 g of biphenyltetracarboxylic dianhydride and 12.2 g of tetrahydrophthalic anhydride were added to the flask, and the reaction was continued at 120 ° C. for 6 hours to obtain a solution of the polymer (A1). Propylene glycol monomethyl ether acetate was further added to the polymer (A1) solution to prepare a polymer (A1) solution of Synthesis Example 1 (solid content concentration: 40% by mass). In addition, the solid content means a heating residue when the polymer (A1) solution is heated at 130 ° C. for 2 hours, and the polymer (A1) is a main component. The acid value of the polymer (A1) contained in the polymer (A1) solution was 95 KOH mg / g, the weight average molecular weight was 8,000, and the equivalent of unsaturated group was 340 g / mol.

<Synthesis Example 2>
27.9 g of YX4000K manufactured by Mitsubishi Chemical Corporation was added to the polymer (A1) solution of Synthesis Example 1 in the flask, and the reaction was continued at 120 ° C. for 3 hours to obtain a solution of the polymer (A2). Propylene glycol monomethyl ether acetate was further added to the polymer (A2) solution to prepare a polymer (A2) solution (solid content concentration: 40% by mass) of Synthesis Example 2. The acid value of the polymer (A2) contained in this polymer (A2) solution was 65 KOH mg / g, the weight average molecular weight was 30,000, and the unsaturated group equivalent was 370 g / mol.

<Synthesis Example 3>
14.2 g of glycidyl methacrylate was added to the polymer (A2) solution of Synthesis Example 2 in the flask, and the reaction was continued at 120 ° C. for 6 hours to obtain a solution of the polymer (A3). Propylene glycol monomethyl ether acetate was further added to the polymer (A3) solution to prepare a polymer (A3) solution of Synthesis Example 3 (solid content concentration: 40% by mass). The acid value of the polymer (A3) contained in the polymer (A3) solution was 48 KOH mg / g, the weight average molecular weight was 34,000, and the equivalent of the unsaturated group was 350 g / mol.

<Synthesis example 4>
A flask equipped with a stirrer, a dropping funnel, a condenser, a thermometer and a gas inlet tube was charged with 84.2 g of propylene glycol monomethyl ether acetate as a solvent and YX4000K 186. manufactured by Mitsubishi Chemical Corporation as a bifunctional epoxy resin having a biphenyl skeleton. Then, the flask was stirred while replacing the inside of the flask with a nitrogen gas / air mixed gas having an oxygen gas concentration of 5 to 7% by volume, and the temperature was raised to 120 ° C.
Next, 6.5 g of itaconic acid, 36.5 g of adipic acid, 0.8 g of triphenylphosphine (catalyst) and 0.8 g of methoquinone (polymerization inhibitor) were added to the flask, and the reaction was continued at 120 ° C. for 10 hours. Thereafter, 28.1 g of acrylic acid was added and the reaction was further continued at 120 ° C. for 10 hours to obtain an epoxy acrylate having a biphenyl skeleton.
Further, 86.6 g of tetrahydrophthalic anhydride was added to the flask, and the reaction was continued at 120 ° C. for 6 hours to obtain a solution of the polymer (A4). Propylene glycol monomethyl ether acetate was further added to the polymer (A4) solution to prepare a polymer (A4) solution of Synthesis Example 4 (solid content concentration: 40% by mass). The acid value of the polymer (A4) contained in this polymer (A4) solution was 93 KOH mg / g, the weight average molecular weight was 8,000, and the unsaturated group equivalent was 770 g / mol.

<Synthesis example 5>
In a flask equipped with a stirrer, a dropping funnel, a condenser, a thermometer and a gas introduction tube, 126.4 g of propylene glycol monomethyl ether acetate as a solvent and YX4000K 186. manufactured by Mitsubishi Chemical Corporation as a bifunctional epoxy resin having a biphenyl skeleton were used. Then, the flask was stirred while replacing the inside of the flask with a nitrogen gas / air mixed gas having an oxygen gas concentration of 5 to 7% by volume, and the temperature was raised to 120 ° C.
Next, 31.7 g of acrylic acid, 33.6 g of acetic acid, 0.8 g of triphenylphosphine (catalyst) and 0.8 g of methoquinone (polymerization inhibitor) were added to the flask. Thereafter, the reaction was continued at 120 ° C. for 10 hours to obtain an epoxy acrylate having a biphenyl skeleton.
Further, 73.5 g of biphenyltetracarboxylic dianhydride and 12.2 g of tetrahydrophthalic anhydride were added to the flask, and the reaction was continued at 120 ° C. for 6 hours to obtain a polymer solution. 27.9 g of YX4000K manufactured by Mitsubishi Chemical Corporation was added to this polymer solution, and the reaction was continued at 120 ° C. for 3 hours to obtain a solution of the polymer (A5). Propylene glycol monomethyl ether acetate was further added to the polymer (A5) solution to prepare a polymer (A5) solution of Synthesis Example 5 (solid content concentration: 40% by mass). The acid value of the polymer (A5) contained in the polymer (A5) solution was 66 KOH mg / g, the weight average molecular weight was 29000, and the unsaturated group equivalent was 830 g / mol.

<Comparative Synthesis Example 1>
194.9 g of propylene glycol monomethyl ether acetate as a solvent was added to a flask equipped with a stirrer, a dropping funnel, a condenser, a thermometer and a gas inlet tube, and the flask was stirred while replacing the inside of the flask with nitrogen gas, and the temperature was raised to 100 ° C. I let it.
Then, 12.6 g of azobisisobutyronitrile (polymerization initiator) was added to a monomer mixture consisting of 88.0 g of benzyl methacrylate and 43.0 g of methacrylic acid to prepare separately. The mixture of the monomer and the polymerization initiator was dropped into the flask from the dropping funnel over 2 hours. After completion of the dropwise addition, the mixture was further stirred at 120 ° C. for 2 hours to carry out a reaction, thereby producing a polymer precursor. Then, the inside of the flask was replaced with a nitrogen gas / air mixed gas having an oxygen gas concentration of 5 to 7% by volume, and 42.6 g of glycidyl methacrylate, 0.5 g of triphenylphosphine (catalyst) and 0.5 g of methoquinone (polymerization inhibitor) were used. Was added. Thereafter, the reaction was continued at 120 ° C. for 6 hours to obtain a solution of the polymer (A6). Propylene glycol monomethyl ether acetate was further added to the polymer (A6) solution to prepare a polymer (A6) solution (solid content concentration: 40% by mass) of Comparative Synthesis Example 1. The acid value of the polymer (A6) contained in the polymer (A6) solution was 63 KOH mg / g, the weight average molecular weight was 10,000, and the unsaturated group equivalent was 600.

<Comparative Synthesis Example 2>
To a flask equipped with a stirrer, a dropping funnel, a condenser, a thermometer and a gas inlet tube, 165.4 g of propylene glycol monomethyl ether acetate and 254.0 g of a fluorene-type epoxy resin as a solvent were added, and the oxygen gas concentration in the flask was 5 to 5. The mixture was stirred while being replaced with a nitrogen gas / air mixed gas of 7% by volume, and heated to 120 ° C.
Next, 72.0 g of acrylic acid, 0.8 g of triphenylphosphine (catalyst) and 0.8 g of methoquinone (polymerization inhibitor) were added to the flask. Thereafter, the reaction was continued at 120 ° C. for 10 hours.
Further, 75.0 g of biphenyltetracarboxylic dianhydride and 38.0 g of tetrahydrophthalic anhydride were added to the flask, and the reaction was continued at 120 ° C. for 6 hours to obtain a solution of the polymer (A7). Propylene glycol monomethyl ether acetate was further added to the polymer (A7) solution to prepare a polymer (A7) solution (solid content concentration: 40% by mass) of Comparative Synthesis Example 2. The acid value of the polymer (A7) contained in the polymer (A7) solution was 97 KOH mg / g, the weight average molecular weight was 5000, and the equivalent of unsaturated group was 440 g / mol.

<Examples 1 to 5 and Comparative Examples 1 and 2>
Using the polymer solutions of Synthesis Examples 1 to 5 and Comparative Synthesis Examples 1 and 2, the photosensitive resin compositions of Examples 1 to 5 and Comparative Examples 1 and 2 were prepared according to the formulation (% by mass) shown in Table 1 below. Prepared. In the following composition, the amount of the polymer (A) does not include the solvent used in the preparation. The amount of the solvent contained in the solution of the polymer (A) is added to the amount of the solvent (B) as a compounding component.

<Evaluation of dispersibility of colorant>
The colorant dispersibility was evaluated by the following method.
First, the photosensitive resin compositions of Examples 1 to 5 and Comparative Examples 1 and 2 were spin-coated on a 5 cm × 5 cm glass substrate so that the thickness of the coating film after post-baking was 1 μm. Thereafter, the solvent was volatilized by heating at 90 ° C. for 3 minutes. Next, the entire surface of the coating film was exposed to light (exposure amount 50 mJ / cm ² ) using Multilight ML-251D / B manufactured by Ushio Inc. and an irradiation optical unit PM25C-100, and was light-cured. Further, post-baking was performed at 230 ° C. for 30 minutes to obtain a target cured coating film. The optical density (Optical Density: OD) of the cured coating film having a thickness of 1 μm was measured by using a transmission densitometer (361T, X-lite). Table 2 shows the results. It can be said that the higher the optical density, the better the colorant dispersibility.

<Evaluation of development margin>
A photosensitive resin composition is spin-coated on a glass substrate in the same manner as in the optical density, baked at 100 ° C. for 3 minutes to evaporate the solvent, and a line-and-space or dot-pattern photomask is installed and exposed. A coating film having a thickness of 2.5 μm after curing was produced. The film was developed with a 0.2% by mass aqueous solution of potassium hydroxide, and the rate of decrease in the thickness of the coating film during a development time of 100 seconds to 150 seconds was measured using a fine shape measuring device ET4000M manufactured by Kosaka Laboratory Co., Ltd. Table 2 shows the results. It can be said that the larger the rate of decrease in the thickness of the coating film, the better the development margin.

<Evaluation of solvent resistance>
A photosensitive resin composition is spin-coated on a glass substrate in the same manner as in the optical density, baked at 100 ° C. for 3 minutes to evaporate the solvent, and a line-and-space or dot-pattern photomask is installed and exposed. A coating film having a thickness of 2.5 μm after curing was produced. Each glass substrate was placed in a 500-mL glass bottle with a cap containing 200 mL of N-methyl-2-pyrrolidone, allowed to stand in an oven at 100 ° C. for 15 minutes, and the presence or absence of color loss was evaluated according to the following criteria. Table 2 shows the results.
：: No color loss at the time of observation with the naked eye ×: Very large color loss at the time of observation with the naked eye

<Evaluation of elastic recovery>
A coating film having a thickness of 4.0 μm after post-baking was prepared on a glass substrate in the same manner as in the optical density, and the compression displacement and the elastic recovery were measured at 25 ° C. using an elasticity measuring device (DUH-211, stock). (Shimadzu Corporation) according to the following measurement conditions.
As a pressing body for pressing the pattern, a flat pressing body having a diameter of 50 μm was used in a load-unloading method. The elastic recovery was measured by a test in which a load of 50 mN was applied. A loading speed of 3 mN / s and a holding time of 10 seconds were kept constant. The elastic recovery ratio means a ratio of a distance recovered after a recovery time of 15 seconds to a distance (compression displacement) compressed when a constant force is applied, and is expressed by the following equation.
Elastic recovery rate (%) = [(recovery distance / compression displacement) × 100]
Table 2 shows the results.

From the above results, the photosensitive resin compositions of Examples 1 to 5 are excellent in colorant dispersibility, development margin, solvent resistance and elastic recovery. On the other hand, the photosensitive resin compositions of Comparative Examples 1 and 2 were low in optical density and inferior in physical properties as a black matrix, or in an elastic recovery test, inferior in physical properties as a spacer.

Claims

A polymer (A) containing a structural unit derived from a bifunctional epoxy resin having a biphenyl skeleton, a structural unit derived from an unsaturated monobasic acid or an unsaturated dibasic acid monoester, and a structural unit derived from a polybasic anhydride; , A photosensitive resin composition containing a solvent (B) and a photopolymerization initiator (C).
感光 The photosensitive resin composition according to claim 1, wherein the polymer (A) further contains a structural unit derived from a dibasic acid.
The photosensitive resin composition according to claim 1 or 2, wherein the polymer (A) further contains a constituent unit derived from a saturated monobasic acid.
The polymer (A) according to any one of claims 1 to 3, wherein the polymer (A) is obtained by adding an epoxy group-containing unsaturated compound to at least a part of the carboxy groups in the structural unit derived from the polybasic acid anhydride. The photosensitive resin composition as described in the above.
5. The polymer according to claim 1, wherein the polymer (A) is obtained by adding a bifunctional epoxy resin to at least a part of carboxy groups in the structural unit derived from the polybasic acid anhydride. Photosensitive resin composition.
The polymer (A) is composed of 30 to 80% by mass of a structural unit derived from the bifunctional epoxy resin having a biphenyl skeleton and 10 to 40 structural units derived from the unsaturated monobasic acid or the unsaturated dibasic acid monoester. 2. The photosensitive resin composition according to claim 1, wherein the composition comprises 10% by mass and 10 to 40% by mass of a structural unit derived from the polybasic anhydride.
The polymer (A) comprises 30 to 80% by mass of a structural unit derived from the bifunctional epoxy resin having a biphenyl skeleton and 5 to 40 structural units derived from the unsaturated monobasic acid or the unsaturated dibasic acid monoester. 3. The photosensitive resin composition according to claim 2, wherein the photosensitive resin composition comprises 5% by mass, 5 to 40% by mass of the structural unit derived from the polybasic acid anhydride, and more than 0% to 20% by mass of the structural unit derived from the dibasic acid. .
The polymer (A) comprises 30 to 80% by mass of a structural unit derived from the bifunctional epoxy resin having a biphenyl skeleton and 5 to 40 structural units derived from the unsaturated monobasic acid or the unsaturated dibasic acid monoester. The photosensitive resin composition according to claim 3, wherein the photosensitive resin composition comprises 5% by mass, 5 to 40% by mass of the structural unit derived from the polybasic acid anhydride, and more than 0% to 20% by mass of the structural unit derived from the saturated monobasic acid. object.
5. The photosensitive resin composition according to claim 4, wherein the addition amount of the epoxy group-containing unsaturated compound is more than 0% by mass to 10% by mass based on the polymer (A).
The photosensitive resin composition according to any one of claims 1 to 9, further comprising a reactive diluent (D).
1 to 20% by weight of the polymer (A), 50 to 94% by weight of the solvent (B), 0.01 to 5% by weight of the photopolymerization initiator (C), and the reactive diluent (D) 11. The photosensitive resin composition according to claim 10, comprising 1 to 20% by mass.
The photosensitive resin composition according to claim 10, further comprising a coloring agent (E).
The photosensitive resin composition according to claim 12, wherein the colorant (E) contains an organic black pigment.
The photosensitive resin composition according to claim 13, wherein the colorant (E) further contains an inorganic black pigment.
1 to 20% by weight of the polymer (A), 50 to 94% by weight of the solvent (B), 0.01 to 5% by weight of the photopolymerization initiator (C), and the reactive diluent (D) The photosensitive resin composition according to any one of claims 12 to 14, which comprises 1 to 20% by mass of the coloring agent (E) and 3 to 30% by mass of the colorant (E) and is used for forming a black column spacer.
A black column spacer obtained by curing the photosensitive resin composition according to claim 15.
An image display device comprising the black column spacer according to claim 16.