KR102146622B1 - Photosensitive resin composition for forming black column spacers, black column spacers, and image display devices - Google Patents

Abstract

At least one type selected from the group consisting of the structural unit (a) having a carboxyl group, the structural unit (b-1) having a (meth)acryloyloxy group, and the structural unit (b-2) having a functional group reacting with a carboxyl group It is a photosensitive resin composition for forming a black column spacer, comprising a resin (A) having a structural unit, a solvent (B), a photoinitiator (C), and a colorant (D). It is preferable that the resin (A) further has a structural unit (c) having an aromatic ring skeleton.

Description

Photosensitive resin composition for forming black column spacers, black column spacers, and image display devices

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

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

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

Japanese Unexamined Patent Publication No. 2015-191234 Japanese Unexamined Patent Publication No. 2014-146029

However, since the photosensitive resin composition for forming the black column spacer has a high optical density (OD), light does not reach the lower portion of the resin layer in the exposure step, so that curing does not proceed well. Therefore, in the prior art, after exposure and development are performed to form a step difference of the black column spacer, patterning is formed by thermal curing in a subsequent post-baking step. In this case, there is a problem in that the step formation margin of the black column spacer is very narrow, so that the height of each step is uniformly maintained over the entire surface of the substrate (an excellent development margin is obtained). In addition, since the lower portion of the resin layer undergoes curing mainly by thermal curing, there is a problem that the necessary chemical resistance is not sufficiently obtained. In addition, when an organic black pigment is used as a light-shielding agent, compared to the case of using an inorganic black pigment such as carbon black, the elution of metal ions and organic black pigments contained in the spacer pattern with respect to the solvent used in the subsequent manufacturing process. There is a problem of solvent resistance that this happens well. Therefore, there is a problem that the reliability of the black column spacer in contact with the liquid crystal is lowered.

An object of the present invention is to provide a photosensitive resin composition for forming a black column spacer having excellent colorant dispersibility, development margin, solvent resistance, and elastic recovery rate.

That is, this invention is represented by the following [1]-[12].

[1] At least selected from the group consisting of a structural unit having a carboxyl group (a), a structural unit having a (meth)acryloyloxy group (b-1), and a structural unit having a functional group reacting with a carboxyl group (b-2) A photosensitive resin composition for forming a black column spacer, comprising a resin (A), a solvent (B), a photoinitiator (C), and a colorant (D) having one structural unit.

[2] The photosensitive resin composition for forming a black column spacer according to [1], wherein the resin (A) further has a structural unit (c) having an aromatic ring skeleton.

[3] For forming a black column spacer according to [1] or [2], wherein the resin (A) further has a structural unit (d) having a crosslinked alicyclic hydrocarbon group having 7 to 20 carbon atoms. Photosensitive resin composition.

[4] The photosensitive resin composition for forming a black column spacer according to [2], wherein the aromatic ring skeleton is at least one selected from the group consisting of a biphenyl skeleton, a naphthalene skeleton, and an anthracene skeleton.

[5] The photosensitive for forming a black column spacer according to any one of [1] to [4], wherein the functional group reacting with the carboxyl group is at least one functional group such as an oxetanyl group, an epoxy group, or an isocyanato group. Resin composition.

[6] The photosensitive resin composition for forming a black column spacer according to any one of [1] to [5], wherein the carboxyl group is a carboxyl group derived from an unsaturated carboxylic acid, a carboxyl group derived from a polybasic acid, or a carboxyl group derived from a polybasic acid anhydride. .

[7] The photosensitive resin composition for forming a black column spacer according to any one of [1] to [6], wherein the resin (A) has an equivalent weight of an unsaturated group of 200 to 2000 g/mol.

[8] The photosensitive resin composition for forming a black column spacer according to any one of [1] to [7], wherein the colorant (D) contains an inorganic black pigment and an organic black pigment.

[9] 1 to 20 mass% of the resin (A), 50 to 94 mass% of the solvent (B), 0.01 to 5 mass% of the photopolymerization initiator (C), and 3 to 30 of the colorant (D) The photosensitive resin composition for forming a black column spacer according to any one of [1] to [8], containing mass%.

[10] The photosensitive resin composition for forming a black column spacer according to [9], further comprising 1 to 20 mass% of a reactive diluent (E).

[11] A black column spacer obtained by curing the photosensitive resin composition for forming a black column spacer according to any one of [1] to [10].

[12] An image display device comprising the black column spacer according to [11].

According to the present invention, it is possible to provide a photosensitive resin composition for forming a black column spacer having excellent colorant dispersibility, development margin, solvent resistance, and elastic recovery rate. The black column spacer obtained by curing the photosensitive resin composition for forming a black column spacer of the present invention is excellent in colorant dispersibility, solvent resistance, and elastic recovery rate.

<Photosensitive resin composition for forming a black column spacer>

Hereinafter, the photosensitive resin composition for forming a black column spacer of the present invention will be described in detail.

The photosensitive resin composition for forming a black column spacer of the present invention comprises a structural unit (a) having a carboxyl group and a structural unit (b-1) having a (meth)acryloyloxy group, and a structural unit (b) having a functional group reacting with a carboxyl group. It contains a resin (A), a solvent (B), a photoinitiator (C), and a colorant (D) having at least one structural unit selected from the group consisting of -2).

In addition, in this specification, "(meth)acryloyloxy group" means at least 1 type selected from acryloyloxy group and methacryloyloxy group, and "(meth)acrylic acid" is acrylic acid and methacrylic It means at least 1 type selected from an acid, and "(meth)acrylate" means at least 1 type selected from acrylate and methacrylate.

<Resin (A)>

The resin (A) used in the present invention is a structural unit (a) having a carboxyl group, a structural unit (b-1) having a (meth)acryloyloxy group, and a structural unit (b-) having a functional group reacting with a carboxyl group. 2) has at least one structural unit selected from the group consisting of. In this specification, the "constituent unit" means a monomer unit forming the main chain of the resin (A). In addition, when another monomer is added to the monomer unit forming the main chain of the resin (A) to form a side chain, the monomer unit of the main chain and the monomer unit forming the side chain are combined to form one ``constituent unit''. To Therefore, the resin (A) used in the present invention includes one having a carboxyl group and a (meth)acryloyloxy group in one structural unit. In addition, in this specification, when one structural unit has a carboxyl group and a (meth)acryloyloxy group, it may express as structural unit (a, b-1).

The structural unit (a) has a carboxyl group. You may have a carboxyl group as an anhydride. The structural unit (a) can be generally introduced into the resin (A) by the following two methods.

The first method is a method (derived from a carboxyl group-containing polymerizable monomer) introduced by using a carboxyl group-containing polymerizable monomer as a polymerizable monomer used when producing the resin (A) by copolymerization. As a carboxyl group-containing polymerizable monomer, for example, (meth)acrylic acid, 2-(meth)acryloyloxyethylsuccinic acid, 2-(meth)acryloyloxyethylhexahydrophthalic acid, α-bromo(meth)acrylic acid, Unsaturated carboxylates such as β-furyl (meth)acrylic acid, crotonic acid, propiolic acid, cinnamic acid, α-cyano cinnamic acid, monomethyl maleate, monoethyl maleate, monoisopropyl maleate, monomethyl fumarate, monoethyl itaconic acid, etc. Acids and the like. These carboxyl group-containing polymerizable monomers 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 second method is an epoxy group by adding an epoxy group-containing (meth)acrylate as a polymerizable monomer to be used when preparing the precursor of the resin (A) by copolymerization, and reacting the epoxy group with the carboxyl group of the carboxyl group-containing monomer. This is a method for introducing a carboxyl group by ring-opening and adding a polybasic acid or polybasic acid anhydride to the hydroxyl group generated at that time. As an epoxy group-containing (meth)acrylate, for example, glycidyl (meth)acrylate, 2-glycidyloxyethyl (meth)acrylate, and 3,4-epoxycyclohexylmethyl (meth)acrylate having an alicyclic epoxy )Acrylate, its lactone adduct (for example, Cychroma (registered trademark) A200, M100 manufactured by Daicel Chemical Industries, Ltd.), 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexane Mono(meth)acrylic acid ester of carboxylate, epoxidation of dicyclopentenyl (meth)acrylate, epoxidation of dicyclopentenyloxyethyl (meth)acrylate, etc. are mentioned. These epoxy group-containing (meth)acrylates may be used alone or in combination of two or more. Among these, glycidyl (meth)acrylate is preferable from the viewpoint of availability and reactivity. Moreover, as a carboxyl group-containing monomer, the unsaturated carboxylic acid enumerated in the 1st method mentioned above can be used. Among them, (meth)acrylic acid is preferred from the viewpoint of reactivity. Examples of the polybasic acid include tetrahydrophthalic acid, hexahydrophthalic acid, 4-methylhexahydrophthalic acid, and succinic acid. Examples of the polybasic acid anhydride include anhydrides of the polybasic acid described above. These polybasic acids and polybasic acid anhydrides may be used alone, or two or more types may be used. Among these, tetrahydrophthalic anhydride is preferred from the viewpoint of improving developability. In the second method, the structural units (a, b-1) having a carboxyl group and a (meth)acryloyloxy group can be introduced into the resin (A).

The structural unit (b-1) can be generally introduced into the resin (A) by the following two methods.

The first method is introduced by using an epoxy group-containing (meth)acrylate as a polymerizable monomer used when preparing the precursor of the resin (A) by copolymerization, and adding a carboxyl group-containing (meth)acrylate to the epoxy group. That's how it is. As for the epoxy group-containing (meth)acrylate, those described above can be used. As a carboxyl group-containing (meth)acrylate, for example, (meth)acrylic acid, 2-(meth)acryloyloxyethylsuccinic acid, 2-(meth)acryloyloxyethylhexahydrophthalic acid, α-bromo(meth) Acrylic acid, β-furyl (meth)acrylic acid, and the like.

The second method is to use a carboxyl group-containing monomer as a polymerizable monomer to be used when preparing the precursor of the resin (A) by copolymerization, and to contain an epoxy group-containing (meth)acrylate or isocyanato group in the carboxyl group (meth ) It is a method of introducing by adding an acrylate. As the carboxyl group-containing monomer, an unsaturated carboxylic acid listed as the above-described carboxyl group-containing polymerizable monomer can be used. As the epoxy group-containing (meth)acrylate, those described above can be used. Examples of the isocyanato group-containing (meth)acrylate include 2-isocyanatoethyl (meth)acrylate.

Although it does not specifically limit as a functional group which reacts with the carboxyl group which the structural unit (b-2) has, Usually, an epoxy group, an oxetanyl group, an isocyanato group, etc. are mentioned, and especially an epoxy group is preferable. The structural unit (b-2) is a polymerizable monomer used when producing the resin (A) by copolymerization, and introduced by using a functional group-containing polymerizable monomer reacting with a carboxyl group (a functional group-containing polymerizable reacting with a carboxyl group It is a method derived from a monomer). As a functional group-containing polymerizable monomer reacting with a carboxyl group, in addition to the above-described epoxy group-containing (meth)acrylate, oxetanyl (meth)acrylate, (meth)acrylic acid (3-methyloxetan-3-yl)methyl, ( Meth)acrylic acid (3-ethyloxetan-3-yl)methyl, (meth)acrylic acid (3-methyloxetan-3-yl) ethyl, (meth)acrylic acid (3-ethyloxetan-3-yl) ethyl, (Meth)acrylic acid (3-chloromethyloxetan-3-yl)methyl, (meth)acrylic acid (oxetan-2-yl)methyl, (meth)acrylic acid (2-methyloxetan-2-yl)methyl, ( Meth)acrylic acid (2-ethyloxetan-2-yl)methyl, (1-methyl-1-oxetanyl-2-phenyl)-3-(meth)acrylate, (1-methyl-1-oxetanyl) )-2-trifluoromethyl-3-(meth)acrylate, (1-methyl-1-oxetanyl)-4-trifluoromethyl-2-(meth)acrylate, etc. containing oxetanyl groups ( Meth)acrylate; Isocyanato group-containing (meth)acrylates, such as 2-isocyanatoethyl (meth)acrylate, etc. are mentioned.

Introducing the structural unit (a) having a carboxyl group, the structural unit (b-1) having a (meth)acryloyloxy group, and the structural unit (b-2) having a functional group reacting with a carboxyl group into the resin (A) The method can be introduced by appropriately combining the above-described structural unit (a), the structural unit (b-1), and the method of introducing the structural unit (b-2). A preferred method is to use a carboxyl group-containing polymerizable monomer and a functional group-containing polymerizable monomer that reacts with a carboxyl group as the polymerizable monomer used when preparing the precursor of the resin (A) by copolymerization, and derived from a carboxyl group-containing polymerizable monomer. An epoxy group-containing (meth)acrylate or an isocyanato group-containing (meth)acrylate may be added to a part of the carboxyl group. As another method, by using an epoxy group-containing (meth)acrylate as a polymerizable monomer used when preparing the precursor of the resin (A) by copolymerization, and adding a carboxyl group-containing (meth)acrylate to a part of the epoxy group, The epoxy group may be ring-opened, and a polybasic acid anhydride may be added to a part of the hydroxyl group generated at that time. That is, as the structural unit introduced into the resin (A) in the latter example, a structural unit (b-2) having a functional group reacting with a carboxyl group, a structural unit (b-1) having a (meth)acryloyloxy group, and a carboxyl group The structural unit (a, b-1) which has a (meth)acryloyloxy group is mentioned.

When the resin (A) used in the present invention further has a structural unit (c) having an aromatic ring skeleton as necessary, the resin (A) having more excellent dispersibility of the colorant can be obtained. The structural unit (c) is a polymerizable monomer used in producing the resin (A) by copolymerization, and is introduced by using an aromatic ring-containing polymerizable monomer (it is derived from an aromatic ring-containing polymerizable monomer). As an aromatic ring-containing polymerizable monomer, for example, styrene, α-methylstyrene, o-vinyltoluene, m-vinyltoluene, p-vinyltoluene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, o -Aromatic vinyl compounds such as methoxystyrene, m-methoxystyrene, p-methoxystyrene, p-nitrostyrene, p-cyanostyrene, and p-acetylaminostyrene; Benzyl (meth)acrylate, rosin (meth)acrylate, phenyl (meth)acrylate, cumyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxy-polyethylene glycol (meth)acrylate (trade name: Light acrylate P-200A, manufactured by Kyei Chemical Co., Ltd.), nonylphenoxy polyethylene glycol mono(meth)acrylate, o-phenoxybenzyl(meth)acrylate, m-phenoxybenzyl(meth)acrylate, p-phenoxy Cybenzyl (meth)acrylate, 4-phenoxyphenyl (meth)acrylate, biphenyloxyethyl (meth)acrylate, ethoxylated o-phenylphenol (meth)acrylate, naphthalene (meth)acrylate, anthracene ( And meth)acrylate. Among these, it is preferable to introduce a structural unit having a skeleton having a plurality of aromatic rings into the resin (A) used in the present invention from the viewpoint of the elastic recovery rate, and selected from the group consisting of a biphenyl skeleton, a naphthalene skeleton, and an anthracene skeleton. It is more preferable to introduce a structural unit having at least one type of.

The resin (A) used in the present invention further has a structural unit (d) having a crosslinked alicyclic hydrocarbon group having 7 to 20 carbon atoms as necessary, thereby obtaining a resin (A) having a more excellent elastic recovery rate. have. The structural unit (d) is a polymerizable monomer used when preparing the resin (A) by copolymerization, and is introduced by using a polymerizable monomer having a crosslinked alicyclic hydrocarbon group having 7 to 20 carbon atoms (the number of carbon atoms It is derived from a polymerizable monomer having a crosslinked alicyclic hydrocarbon group of 7 to 20). The crosslinked alicyclic hydrocarbon means having a structure represented by the following formula (1) or (2) represented by adamantane, norbornane, and the like. The crosslinked alicyclic hydrocarbon group refers to a group corresponding to the rest of the structures excluding some hydrogen atoms.

[Formula 1]

(In formula (1), A ¹ and B ¹ each independently represent a linear or branched alkylene group (which may include a ring), and R ⁴ represents a hydrogen atom or a methyl group. A ¹ and B ¹ are, Branches of A ¹ and B ¹ may be connected to each other to form a cyclic shape.)

[Formula 2]

(In formula (2), A ² , B ² and L each independently represent a linear or branched alkylene group (which may include a ring), and R ⁵ represents a hydrogen atom or a methyl group. A ² , B ² And L may be cyclic by connecting branches of A ² , B ^2, and L.)

Among the monomers having the above structure, (meth)acrylate having a crosslinked alicyclic hydrocarbon group having 7 to 20 carbon atoms is preferable, and adamantyl (meth)acrylate and (meth)acrylate having a structure represented by the following formula (3) ) Acrylate is more preferable.

[Formula 3]

(In formula (3), R ⁶ to R ⁸ each independently represent a hydrogen atom or a methyl group. R ⁹ and R ¹⁰ are either a hydrogen atom or a methyl group, or are connected to each other to be a saturated or unsaturated ring (preferably 5-membered ring or 6-membered ring) may be formed In formula (3), * represents a bond hand connected to a (meth)acryloyloxy group.)

As a polymerizable monomer having a crosslinked alicyclic hydrocarbon group having 7 to 20 carbon atoms, for example, dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, isobornyl (meth) acrylate, And adamantyl (meth)acrylate. Among these, dicyclopentanyl methacrylate is preferable from the viewpoint of heat decomposition resistance and heat discoloration resistance. These polymerizable monomers may be used alone, or two or more types may be used.

In addition, norbornene-based monomers represented by the following formula (4) can also be used as a preferred polymerizable monomer for introducing the structural unit (d).

[Formula 4]

(In formula (4), X and Y each independently represent a hydrogen atom or a linear or branched hydrocarbon group having 1 to 4 carbon atoms, and R ¹ and R ² each independently represent a hydrogen atom or a carboxyl group Or a hydrocarbon group having 1 to 20 carbon atoms (which may have a substituent). R ¹ and R ² may be connected to each other to form a cyclic structure.)

Here, as specific examples of the linear or branched hydrocarbon group having 1 to 4 carbon atoms, a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, and t-butyl group are mentioned. . In addition, specific examples of the hydrocarbon group having 1 to 20 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, t-amyl group, stearyl group, and A linear or branched alkyl group such as a uryl group and a 2-ethylhexyl group; Aryl groups such as phenyl groups; Alicyclic groups, such as a cyclohexyl group, t-butylcyclohexyl group, a dicyclopentadienyl group, a tricyclodecanyl group, an isobornyl group, an adamantyl group, and a 2-methyl-2-adamantyl group, are mentioned. Specific examples of the substituent include an alkoxy group such as a methoxy group and an ethoxy group, and an aryl group such as a phenyl group.

As specific examples of the norbornene-based monomer, norbornene (bicyclo[2.2.1] hepto-2-ene), 5-methylbicyclo[2.2.1]hepto-2-ene, and 5-ethylbicyclo[2.2. 1]Hepto-2-ene, tetracyclo[4.4.0.12,5.17,10]dodeca-3-ene, 8-methyltetracyclo[4.4.0.12,5.17,10]dodeca-3-ene, 8-ethyl Tetracyclo[4.4.0.12,5.17,10]dodeca-3-ene, dicyclopentadiene, tricyclo[5.2.1.02,6]deca-8-ene, tricyclo[5.2.1.02,6]deca-3 -Ene, tricyclo[4.4.0.12,5]undeca-3-ene, tricyclo[6.2.1.01,8]undeca-9-ene, tricyclo[6.2.1.01,8]undeca-4-ene , Tetracyclo[4.4.0.12,5.17,10.01,6]dodeca-3-ene, 8-methyltetracyclo[4.4.0.12,5.17,10.01,6]dodeca-3-ene, 8-ethylidenetetracyclo [4.4.0.12,5.17,12]dodeca-3-ene, 8-ethylidenetetracyclo[4.4.0.12,5.17,10.01,6]dodeca-3-ene, pentacyclo[6.5.1.13,6.02,7.09 ,13]pentadeca-4-ene, pentacyclo[7.4.0.12,5.19,12.08,13]pentadeca-3-ene, and the like. Among these, norbornene and dicyclopentadiene are preferable from the viewpoint of thermal decomposition resistance and heat discoloration resistance. These norbornene-based monomers may be used alone, or two or more types may be used.

The resin (A) used in the present invention may have, if necessary, a structural unit derived from a radical polymerizable monomer having an ethylenic carbon-carbon double bond other than the structural unit described above. The constituent unit derived from a radically polymerizable monomer having an ethylenic carbon-carbon double bond is a polymerizable monomer used when preparing the resin (A) by copolymerization, and a radically polymerizable monomer having an ethylenic carbon-carbon double bond It is introduced by using Examples of the radically polymerizable monomer having an ethylenic carbon-carbon double bond include diene compounds such as butadiene, isoprene, and chloroprene; 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, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, ethylcyclohexyl (meth)acrylic Rate, 1,4-cyclohexanedimethanol mono(meth)acrylate, norbornyl(meth)acrylate, 5-methylnorbornyl(meth)acrylate, 5-ethylnorbornyl(meth)acrylate, Tetrahydrofurfuryl (meth)acrylate, 1,1,1-trifluoroethyl (meth)acrylate, perfluoroethyl (meth)acrylate, perfluoro-n-propyl (meth)acrylate, purple Luoro-isopropyl(meth)acrylate, 3-(N,N-dimethylamino)propyl(meth)acrylate, triphenylmethyl(meth)acrylate, (meth)acryloyloxyethylisocyanate (i.e. 2- (Meth)acrylic acid ester compounds such as a reaction product of isocyanatoethyl (meth)acrylate) and ε-caprolactam, and a reaction product of (meth)acryloyloxyethyl isocyanate and propylene glycol monomethyl ether; (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 (Meth)acrylic acid amides, such as isopropylamide and (meth)acrylate anthracenylamide; Vinyl compounds such as anilide (meth)acrylate, (meth)acrylonitrile, acrolein, vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, N-vinylpyrrolidone, vinylpyridine, vinyl acetate, and vinyltoluene; Unsaturated dicarboxylic acid diester compounds such as diethyl citracate, diethyl maleate, diethyl fumarate, and diethyl itaconic acid; And monomaleimide compounds such as N-phenylmaleimide, N-cyclohexylmaleimide, N-laurylmaleimide, and N-(4-hydroxyphenyl)maleimide.

The reaction conditions in the copolymerization reaction for obtaining the resin (A) used in the present invention or the copolymerization reaction for obtaining the resin (A) precursor before performing the addition reaction may be appropriately set according to a conventional method. The copolymerization reaction may be carried out for 1 to 12 hours at preferably 50 to 150°C, more preferably 60 to 140°C while dropping the polymerizable monomer and polymerization initiator for copolymerization in a solvent. In the addition reaction to the resin (A) precursor, a monomer for addition reaction with the resin (A) precursor is added to the solvent, and an addition reaction catalyst is further added, preferably 50 to 150°C, more preferably 80. What is necessary is just to react at -130 degreeC for 3-12 hours. Moreover, in this addition reaction, even if the solvent used for the copolymerization reaction for obtaining the resin (A) precursor is contained, there is no problem. Therefore, after the copolymerization reaction for obtaining the resin (A) precursor is completed, the addition reaction can be continuously carried out without removing the solvent.

The preferred structural unit ratio of the resin (A) used in the present invention is as follows (I) to (IV).

(I) The resin (A) having the structural unit (a) having a carboxyl group and the structural unit (b-1) having a (meth)acryloyloxy group is 10 to 70 mol% of the structural unit (a) and 10 to It is preferable to have 80 mol% of structural unit (b-1), and it is more preferable to have 20 to 60 mol% of structural unit (a) and 15 to 70 mol% of structural unit (b-1).

(II) The resin (A) having the structural unit (a) having a carboxyl group and the structural unit (b-2) having a functional group reacting with the carboxyl group is 10 to 80 mol% of the structural unit (a) and 10 to 70 mol It is preferable to have a structural unit (b-2) of %, and it is more preferable to have a structural unit (a) of 20 to 70 mol% and a structural unit (b-2) of 15 to 60 mol%.

(III) The structural unit (a) having a carboxyl group, the structural unit (b-1) having a (meth)acryloyloxy group, and the resin (A) having a structural unit (b-2) having a functional group reacting with a carboxyl group are , It is preferable to have 10 to 70 mol% of the structural unit (a), 10 to 70 mol% of the structural unit (b-1) and 10 to 50 mol% of the structural unit (b-2), and 20 to 60 mol It is more preferable to have the structural unit (a) of %, the structural unit (b-1) of 20 to 60 mol%, and the structural unit (b-2) of 20 to 40 mol%.

(IV) a structural unit (a, b-1) having a carboxyl group and a (meth)acryloyloxy group, and a structural unit having a (meth)acryloyloxy group (b-1) and a structural unit having a functional group reacting with a carboxyl group The resin (A) having (b-2) has a constitutional unit (a, b-1) of 10 to 80 mol%, a constitutional unit (b-1) of 10 to 80 mol%, and a constitution of 1 to 10 mol% It is preferable to have a unit (b-2), 20-70 mol% of structural units (a, b-1), 15-70 mol% of structural units (b-1), and 1-5 mol% of structural units It is more preferable to have (b-2).

When the structural unit (a) having a carboxyl group is 10 mol% or more, developability becomes good, which is preferable. On the other hand, if the proportion of the structural unit (a) having a carboxyl group is equal to or less than the above upper limit, it is preferable because it can prevent a decrease in the residual film rate during development.

When the structural unit (b-1) having a (meth)acryloyloxy group is 10 mol% or more, since solvent resistance and developability become good, it is preferable. On the other hand, if the ratio of the structural unit (b-1) having a (meth)acryloyloxy group is not more than the above upper limit, it is preferable because it can suppress the occurrence of a residue during development.

When the structural unit (b-2) having a functional group reacting with a carboxyl group is 10 mol% or more, since solvent resistance becomes good, it is preferable. On the other hand, when the proportion of the structural unit (b-2) having a functional group reacting with a carboxyl group is not more than the above upper limit, storage stability becomes good, which is preferable.

In the resin (A) of (I), (II), (III) and (IV), if necessary, a structural unit having an aromatic ring skeleton (c) and a crosslinked alicyclic hydrocarbon group having 7 to 20 carbon atoms The unit (d) or a structural unit other than that can be introduced.

When introducing the structural unit (c) which has an aromatic ring skeleton, it is preferable that it is more than 0 mol%-50 mol% of the structural unit of resin (A), and it is more preferable that it is more than 0 mol%-40 mol%.

When introducing the structural unit (d) having a crosslinked alicyclic hydrocarbon group having 7 to 20 carbon atoms, it is preferably more than 0 mol% to 40 mol% of the constitutional unit of the resin (A), and more than 0 mol% to 30 It is more preferable that it is mol%.

When introducing a structural unit other than that, it is preferable that it is more than 0 mol%-60 mol% of the structural unit of resin (A), and it is more preferable that it is more than 0 mol%-50 mol%.

It does not specifically limit as a solvent which can be used for a copolymerization reaction, A well-known thing can be used suitably. As a specific example of the solvent, 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, triethylene 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 , (Poly)alkylene glycol monoalkyl ethers such as dipropylene glycol mono-n-butyl ether, tripropylene glycol monomethyl ether, and tripropylene glycol monoethyl ether; (Poly) alkylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl 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; 2-hydroxymethylpropionate, 2-hydroxypropionate ethyl, 2-hydroxy-2-methylpropionate methyl, 2-hydroxy-2-methylpropionate ethyl, 3-methoxypropionate methyl, 3-methoxyethylpropionate, 3-ethoxy methyl propionate, 3-ethoxy ethyl propionate, ethyl ethoxy acetate, ethyl hydroxyacetate, 2-hydroxy-3-methyl butyrate methyl, 3-methyl-3-methoxybutyl acetate, 3-methyl- 3-methoxybutylpropionate, ethyl acetate, n-butyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, n-amyl acetate, i-amyl acetate, n-propionic acid Ester compounds such as butyl, ethyl butyrate, n-propyl butyrate, i-propyl butyrate, n-butyl butyrate, methyl pyruvate, ethyl pyruvate, n-propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, and ethyl 2-oxobutyrate; Aromatic hydrocarbon compounds such as toluene and xylene; Carboxylic acid amide compounds, such as N-methylpyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide, etc. are mentioned. These solvents may be used alone, or two or more types may be used.

Among these, (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 preferred.

The amount of the solvent used for the copolymerization reaction is not particularly limited, but generally 30 to 1000 parts by mass, preferably 50 to 800 parts by mass, when the total amount of the monomers injected is 100 parts by mass. When the amount of the solvent used is 1000 parts by mass or less, it is preferable because a decrease in the molecular weight of the resin (A) due to a chain transfer action can be efficiently suppressed and the viscosity of the resin (A) can be controlled within an appropriate range. On the other hand, when the amount of the solvent is 30 parts by mass or more, it is possible to prevent abnormality in the copolymerization reaction and to perform the copolymerization reaction stably, which is preferable. Moreover, coloring and gelation of the resin (A) can also be prevented.

It does not specifically limit as a polymerization initiator which can be used for a copolymerization reaction, A well-known thing can be used suitably. Specific examples of the polymerization initiator include azobisisobutyronitrile, azobisisovaleronitrile, benzoyl peroxide, and t-butylperoxy-2-ethylhexanoate. These polymerization initiators may be used alone, or two or more of them may be used. The amount of the polymerization initiator used is not particularly limited, but when the total injection amount of the monomer is 100 parts by mass, it is generally 0.5 to 20 parts by mass, preferably 0.7 to 15 parts by mass, and more preferably 1 to 10 parts by mass. It is a mass part.

The kind of the addition reaction catalyst used for addition reaction of a monomer to the resin (A) precursor is not specifically limited, It is selected as needed. Examples of the addition reaction catalyst include tertiary amines such as triethylamine, quaternary ammonium salts such as triethylbenzyl ammonium chloride, phosphorus compounds such as triphenylphosphine, and chelate compounds of chromium. These addition reaction catalysts may be used alone, or two or more types may be used. The amount of the addition reaction catalyst to be used is not particularly limited, but when the amount of the resin (A) precursor is 100 parts by mass, it is generally 0.01 to 5 parts by mass, preferably 0.1 to 2 parts by mass, and more preferably Is 0.2 to 1 part by mass.

When adding a monomer to the resin (A) precursor, it is preferable to add a polymerization inhibitor to prevent gelation. The kind of polymerization inhibitor is not particularly limited and is selected as needed. As a polymerization inhibitor, hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, butylhydroxytoluene, etc. are mentioned, for example. These polymerization inhibitors may be used alone, or two or more of them may be used. The amount of the polymerization inhibitor to be used is not particularly limited, but when the amount of the resin (A) precursor is 100 parts by mass, it is generally 0.01 to 5 parts by mass, preferably 0.1 to 2 parts by mass, more preferably Is 0.2 to 1 part by mass.

As for the resin (A) used in the present invention, the weight average molecular weight obtained in terms of polystyrene by gel permeation chromatography (GPC) is preferably from 1000 to 50000, and more preferably from 3000 to 40000. When the weight average molecular weight is 1000 or more, it is preferable because no defect of the pattern occurs after alkali development. On the other hand, when the weight average molecular weight is 50000 or less, the developing time becomes a suitable time, and it is preferable because it is practical for use. Moreover, it is preferable that the weight average molecular weight of resin (A) is 3000-30000 from a viewpoint of an elastic recovery rate.

The acid value (JIS K6901 5.3) of the resin (A) used in the present invention is not limited as long as it exhibits the desired effect of the present invention, but is usually 20 to 300 KOHmg/g, preferably 30 to 200 KOHmg/g. . When the acid value is 20 KOHmg/g or more, developability becomes good, which is preferable. On the other hand, when the acid value is 300 KOHmg/g or less, it is preferable because the exposed portion (photocured portion) is not easily dissolved in an alkali developer. Moreover, it is preferable that the acid value of the resin (A) is 30-200 KOHmg/g from a viewpoint of an elastic recovery rate.

The unsaturated group equivalent of the resin (A) used in the present invention is not limited as long as it exhibits the desired effect of the present invention, but is usually 100 to 4000 g/mol, preferably 200 to 2000 g/mol, more Preferably it is 300 to 500 g/mol. When the unsaturated group equivalent is 100 g/mol or more, since it is effective in improving the coating film physical properties and alkali developability, it is preferable. On the other hand, when the unsaturated group equivalent is 4000 g/mol or less, since it is effective in increasing the sensitivity, it is preferable. Moreover, it is preferable that the unsaturated group equivalent of resin (A) is 200-2000 g/mol from a viewpoint of an elastic recovery rate. Moreover, the unsaturated group equivalent is the mass of resin (A) per 1 mol of unsaturated bond (ethylenic carbon-carbon double bond) in resin (A). The unsaturated group equivalent can be obtained by dividing the mass of the resin (A) by the number of unsaturated groups in the resin (A) (g/mol). In addition, in this specification, the unsaturated group equivalent is a theoretical value calculated from the injection amount of the raw material used to introduce an unsaturated group.

The epoxy equivalent of the resin (A) used in the present invention is not limited as long as it exhibits the desired effect of the present invention, but is usually 100 to 4000 g/mol, preferably 200 to 2000 g/mol, more preferably It is 300 to 500 g/mol. When the epoxy equivalent is 100 g/mol or more, it is effective in improving the physical properties and storage stability of the coating film, and is preferable. Conversely, when the epoxy equivalent weight is 4000 g/mol or less, it is effective to further increase the solvent resistance. Moreover, the said epoxy equivalent is the mass of a polymer per 1 mole of the epoxy group of a polymer. This value can be obtained by dividing the mass of the polymer by the amount of epoxy groups in the polymer (g/mol). In this specification, "epoxy equivalent" is a theoretical value calculated from the injection amount of the raw material used to introduce an epoxy group.

<Solvent (B)>

The solvent (B) used in the present invention is not particularly limited as long as it is an inert solvent that can dissolve the resin (A) and does not react with the resin (A), and can be selected arbitrarily. Moreover, it is preferable that the solvent (B) has compatibility with the reactive diluent mentioned later. As the solvent (B), the same solvents that can be used when producing the resin (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 isolate the target resin (A) from the resin (A) solution after the copolymerization reaction has been completed, and can be appropriately added to the isolated resin (A). However, it is not always necessary to isolate the target resin (A) from the resin solution. The solvent contained at the end of the copolymerization reaction can also be used as it is as the solvent (B) without separating from the resin (A) solution. If necessary, another solvent may be added to the resin (A) solution. Further, a solvent contained in the other components used when preparing the photosensitive resin composition for forming a black column spacer may be used as it is as the solvent (B).

<Photopolymerization initiator (C)>

Although it does not specifically limit as a photoinitiator (C) used by this invention, For example, Benzoin compounds, such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin butyl ether; Acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 4-(1-t-butyldioxy-1-methylethyl)acetophenone, 2-methyl-1-[ Acetophenone compounds such as 4-(methylthio)phenyl]-2-morpholino-propan-1-one and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone-1; Anthraquinone compounds such as 2-methylanthraquinone, 2-amylanthraquinone, 2-t-butylanthraquinone, and 1-chloroanthraquinone; Xanthone compounds such as xanthone, thioxanthone, 2,4-dimethyl thioxanthone, 2,4-diisopropyl thioxanthone, and 2-chlorothioxanthone; Ketal compounds such as acetophenone dimethyl ketal and benzyl dimethyl ketal; Benzophenone compounds such as benzophenone, 4-(1-t-butyldioxy-1-methylethyl)benzophenone, and 3,3',4,4'-tetrakis(t-butyldioxycarbonyl)benzophenone ; And acylphosphine oxide compounds. These photoinitiators may be used individually or may use 2 or more types.

<Coloring agent (D)>

The colorant (D) used in the present invention is not particularly limited as long as it is dissolved or dispersed in the solvent (B), and examples thereof include dyes and pigments. Dye and pigment may be used individually, may use 2 or more types, or may be used combining dye and pigment. In the case of forming the black column spacer of the present invention, the photosensitive resin composition for forming the black column spacer contains a black pigment as a coloring agent (D) from the viewpoint of solubility in a solvent (B) and an alkali developer, interaction with other components, and light blocking properties. It is preferable to contain as ).

Examples of the black pigment include inorganic black pigments and organic black pigments, and specifically, 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 two or more types may be used. From the viewpoint of optical density, it is preferable to use an inorganic black pigment and an organic black pigment together, and it is more preferable to use a carbon black and a lactam type organic black together.

When a pigment is used as the colorant (D), from the viewpoint of improving the dispersibility of the pigment, a known dispersant may be incorporated into the photosensitive resin composition for forming a black column spacer. As the dispersant, it is preferable to use a polymeric dispersant because it has excellent dispersion stability over time. The polymeric dispersant can be arbitrarily selected, but for example, a urethane-based dispersant, a polyethyleneimine-based dispersant, a polyoxyethylene alkyl ether-based dispersant, a polyoxyethylene glycol diester-based dispersant, a sorbitan aliphatic ester-based dispersant, an aliphatic modified ester-based dispersant, etc. Can be mentioned. As such a polymeric dispersant, EFKA (registered trademark, manufactured by BASF Japan), Disperbyk (registered trademark, manufactured by Vicchemy), Disparon (registered trademark, manufactured by Kusumoto Chemical Co., Ltd.), SOLSPERSE (registered trademark, manufactured by Geneva Corporation) You may use what is marketed under a brand name such as. The blending amount of the dispersant may be appropriately set according to the kind of pigment to be used.

In the photosensitive resin composition for forming a black column spacer of the present invention, the preferred blending amounts of the resin (A), the solvent (B), the photoinitiator (C) and the colorant (D) are as follows.

It is preferable that it is 1-20 mass% with respect to the whole photosensitive resin composition, and, as for the compounding quantity of resin (A), it is more preferable that it is 5-15 mass %. When the blending amount of the resin (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 resin (A) is 20% by mass or less, it is preferable because it has good coatability.

The blending amount of the solvent (B) is preferably 50 to 94% by mass, and more preferably 60 to 90% by mass with respect to the whole photosensitive resin composition. When the blending amount of the solvent (B) is 50% by mass or more, it is preferable because it has good coatability. On the other hand, if the compounding amount of the solvent (B) is 94% by mass or less, it is preferable because the coating film has a sufficient film thickness.

The amount of the photoinitiator (C) added is preferably 0.01 to 5% by mass, and more preferably 0.1 to 2% by mass with respect to the whole photosensitive resin composition. When the blending amount of the photoinitiator (C) is 0.01% by mass or more, it is preferable because the resist has curability. On the other hand, if the blending amount of the photoinitiator (C) is 5% by mass or less, it is preferable because a residue after development is hardly generated.

It is preferable that it is 3-30 mass% with respect to the whole photosensitive resin composition, and, as for the compounding amount of a coloring agent (D), it is more preferable that it is 5-20 mass %. When the blending amount of the coloring agent (D) is 3% by mass or more, it is preferable because it has light-shielding properties. On the other hand, when the blending amount of the coloring agent (D) is 30 mass% or less, it is preferable because a residue after development hardly occurs.

The photosensitive resin composition for forming a black column spacer of the present invention may further contain a reactive diluent (E) from the viewpoint of viscosity adjustment and sensitivity adjustment.

<Reactive diluent (E)>

The reactive diluent (E) is a compound having at least one ethylenically unsaturated group in the molecule. Among them, a compound having a plurality of ethylenically unsaturated groups is preferable. The reactive diluent (E) is not an essential component of the photosensitive resin composition for forming a black column spacer. However, by using the reactive diluent (E) in combination with the resin (A), the film strength of the coating film formed from the photosensitive resin composition for forming a black column spacer and adhesion to the substrate can be improved.

As the monofunctional monomer used as the reactive diluent (E), for example, (meth)acrylamide, methylol (meth)acrylamide, methoxymethyl (meth)acrylamide, ethoxymethyl (meth)acrylamide, pro Foxymethyl (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-hydroxypropylphthalate, glycerin mono(meth)acrylate, tetrahydrofurfuryl(meth)acrylate, glycidyl(meth)acrylate, 2,2,2-tri (Meth)acrylate compounds such as fluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, and half (meth)acrylate of a phthalic acid derivative; Aromatic vinyl compounds such as styrene, α-methylstyrene, α-chloromethylstyrene, and vinyl toluene; Carboxylate esters, such as vinyl acetate and vinyl propionate, are mentioned. These monofunctional monomers may be used alone or in combination of two or more.

As the polyfunctional monomer used as the reactive diluent (E), for example, 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, butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexane glycol di(meth)acrylate, trimethylol Propane tri(meth)acrylate, glycerin di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaeryth Litholhexa(meth)acrylate, 2,2-bis(4-(meth)acryloxydiethoxyphenyl)propane, 2,2-bis(4-(meth)acryloxypolyethoxyphenyl)propane, 2-hydride Roxy-3-(meth)acryloyloxypropyl(meth)acrylate, ethylene glycol diglycidyl ether di(meth)acrylate, diethylene glycol diglycidyl ether di(meth)acrylate, phthalate digly Cydyl ester di(meth)acrylate, glycerin triacrylate, glycerin polyglycidyl ether poly(meth)acrylate, urethane (meth)acrylate (i.e. tolylene diisocyanate), trimethylhexamethylene diisocyanate and hexamethylene (Meth)acrylate compounds such as reactants of diisocyanate and the like of 2-hydroxyethyl (meth)acrylate, and tri(meth)acrylate of tris(hydroxyethyl)isocyanurate; Aromatic vinyl compounds such as divinylbenzene, diallylphthalate, and diallylbenzenephosphonate; Dicarboxylic acid ester compounds such as divinyl adipate; Triallyl cyanurate, methylenebis(meth)acrylamide, (meth)acrylamide methylene ether, and condensation products of a polyhydric alcohol and N-methylol(meth)acrylamide. These polyfunctional monomers may be used alone or in combination of two or more.

In the case of blending the reactive diluent (E), the blending amount is preferably 1 to 20% by mass, more preferably 2 to 10% by mass with respect to the whole photosensitive resin composition. When the blending amount of the reactive diluent (E) is 1% by mass or more, it is preferable because it has good curability. On the other hand, when the blending amount of the reactive diluent (E) is 20% by mass or less, it is preferable because a residue after development hardly occurs.

Further, the photosensitive resin composition for forming a black column spacer of the present invention may contain known additives such as a coupling agent, a leveling agent, and a thermal polymerization inhibitor within a range that does not impair the effect of the present invention. The blending amount of these additives is not particularly limited as long as the effect of the present invention is not impaired.

The photosensitive resin composition for forming a black column spacer of the present invention can be produced by mixing each component described above using a known mixing device. Further, if desired, after preparing a composition containing the resin (A) and the solvent (B) in advance, a photopolymerization initiator (C), a colorant (D) and an optional reactive diluent (E) as an optional component are further added and mixed. It can also be manufactured.

<Black column spacer>

Next, the black column spacer of the present invention will be described in detail.

The black column spacer of the present invention is obtained by curing the photosensitive resin composition for forming the black column spacer described above. Specifically, first, a photosensitive resin composition for forming a black column spacer is applied on a substrate to form a resin layer (coating film). After that, the resin layer is exposed through a halftone mask of a predetermined pattern, and the exposed portion is photocured. Then, the unexposed portion and the semi-exposed portion are developed with an alkali developer to form a black column spacer. After that, the black column spacer is post-baked as necessary.

The material of the substrate is not particularly limited, and for example, 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, an array substrate And the like.

The coating method of 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 application of the photosensitive resin composition for forming a black column spacer, if necessary, the solvent (B) contained in the resin layer may be volatilized by heating using a heating means such as a circulation oven, an infrared heater, or a hot plate. The heating conditions are not particularly limited, and may be appropriately set according to the kind of the photosensitive resin composition for forming a black column spacer to be used. In general, it is preferable to heat at a temperature of 50°C to 120°C for 30 seconds to 30 minutes.

Although the exposure method of the resin layer is not particularly limited, for example, irradiation of active energy rays such as ultraviolet rays and excimer laser light may be mentioned. The energy dose to be irradiated may be appropriately set according to the composition of the photosensitive resin composition for forming a black column spacer. For example, although it is preferable that it is 30-2000 mJ/cm<2>, it is not limited to this range. The light source used for 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 such as sodium carbonate, potassium carbonate, calcium carbonate, sodium hydroxide, and potassium hydroxide; 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-methanesulfonamide ethylaniline, 3-methyl-4-amino-N-ethyl-N-β-methoxyethylaniline and p-phenylene such as sulfate, hydrochloride or p-toluenesulfonate And aqueous solutions of diamine compounds. Moreover, you may add a defoaming agent, a surfactant, etc. to these alkaline developing solutions as needed. In addition, after development with an alkali developer, it is preferable to wash with water and dry.

By post-baking the black column spacer formed by alkali development, curing of the resin can be further advanced. The conditions for post-baking are not particularly limited and can be selected arbitrarily. Depending on the composition of the photosensitive resin composition for forming a black column spacer, preferable conditions may be selected to perform heat treatment. For example, at a temperature of 130°C to 250°C, heating is preferably performed for 10 minutes to 4 hours, more preferably 20 minutes to 2 hours.

The black column spacer produced in this way is excellent in colorant dispersibility, solvent resistance, and elastic recovery rate.

<Image display device>

The image display device of the present invention is an image display device including the black column spacer described above. As a specific example of an image display device, a liquid crystal display device, an organic EL display device, etc. are mentioned. In manufacturing the image display device, there is no limitation other than forming the black column spacer described above, and manufacturing can be performed according to a conventional method.

Example

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

<Synthesis Example 1>

To a flask equipped with a stirring device, a dropping funnel, a condenser, a thermometer, and a gas introduction tube, propylene glycol monomethyl ether acetate 139 g was added as a solvent, and the flask was stirred while being replaced with nitrogen gas, and the temperature was raised to 120°C.

Then, to a monomer mixture consisting of 22.0 g (0.1 mol) of tricyclodecanyl methacrylate, 70.0 g (0.4 mol) of benzyl methacrylate, and 43.0 g (0.5 mol) of methacrylic acid, t-butylperoxy-2- What added 6.6 g of ethylhexanoate (polymerization initiator, Nichiyu Corporation make, Perbutyl (registered trademark) O) was separately prepared. The mixture of this monomer and a polymerization initiator was dripped into the flask over 2 hours from a dropping funnel. After completion of the dropwise addition, the mixture was stirred at 120° C. for 2 hours to perform a copolymerization reaction to synthesize the precursor of the resin (A). After that, the flask was replaced with air, and glycidyl methacrylate 21.3 g (0.15 mol), triphenylphosphine (catalyst) 0.5 g and butylhydroxytoluene (polymerization inhibitor) 0.5 g were added to the resin ( A) It was added to the precursor solution. Then, reaction was continued at 110 degreeC over 10 hours, and the solution of resin (A) was obtained. This resin is referred to as "resin (A-1)". The acid value of the resin (A-1) contained in this resin solution was 126 KOHmg/g, the weight average molecular weight was 10000 and the unsaturated group equivalent was 1100.

To this resin solution, propylene glycol monomethyl ether acetate was further added to prepare a resin (A-1) solution (solid content concentration 40% by mass) of Synthesis Example 1. Moreover, the solid content means the heating residual content when the resin solution is heated at 130 degreeC for 2 hours, and the resin (A-1) and a polymerization initiator become a main component.

<Synthesis Example 2>

To a flask equipped with a stirring device, a dropping funnel, a condenser, a thermometer, and a gas introduction tube, 140 g of propylene glycol monomethyl ether acetate was added as a solvent, and the flask was stirred while being substituted with nitrogen gas, and the temperature was raised to 120°C.

Subsequently, to a monomer mixture consisting of 66.0 g (0.3 mol) of tricyclodecanyl methacrylate, 31.2 g (0.3 mol) of styrene, and 56.8 g (0.4 mol) of glycidyl methacrylate, t-butylperoxy-2- What added 7.3 g of ethylhexanoate (polymerization initiator, Nichiyu Corporation make, Perbutyl (registered trademark) O) was prepared separately. The mixture of this monomer and a polymerization initiator was dripped into the flask over 2 hours from a dropping funnel. After completion of the dropwise addition, the mixture was stirred at 120° C. for 2 hours and copolymerized to produce a precursor of the resin (A). Then, the inside of the flask was replaced with air, and acrylic acid 28.8 g (0.4 mol), triphenylphosphine (catalyst) 0.6 g and butylhydroxytoluene (polymerization inhibitor) 0.6 g were added to the resin (A) precursor solution. Was put in. After that, the reaction was continued at 110° C. over 10 hours. Subsequently, 38.0 g (0.25 mol) of tetrahydrophthalic anhydride was added to the flask, and the reaction was continued at 110° C. over 3 hours to obtain a solution of the resin (A). This resin is referred to as "resin (A-2)". The acid value of the resin (A-2) contained in this resin solution was 65 KOHmg/g, the weight average molecular weight was 9400 and the unsaturated group equivalent was 600. In the same manner as in Synthesis Example 1, propylene glycol monomethyl ether acetate was added to prepare a resin (A-2) solution (solid content concentration 40% by mass) of Synthesis Example 2.

<Synthesis Example 3>

To a flask equipped with a stirring device, a dropping funnel, a condenser, a thermometer, and a gas introduction tube, 191 g of propylene glycol monomethyl ether acetate was added as a solvent, and the flask was stirred while being substituted with nitrogen gas, and the temperature was raised to 100°C.

Then, tricyclodecanyl methacrylate 22.0 g (0.1 mol), methyl methacrylate 50.0 g (0.5 mol), methacrylic acid 21.5 g (0.25 mol) and glycidyl methacrylate 21.3 g (0.15 mol) To the resulting monomer mixture, 12.6 g of azobisisobutyronitrile was added to prepare separately. The mixture of this monomer and a polymerization initiator was dripped into the flask over 2 hours from a dropping funnel. After completion of the dropwise addition, it was stirred at 100° C. for 2 hours and copolymerized to obtain a solution of the resin (A). This resin is referred to as "resin (A-3)". The acid value of the resin (A-3) contained in this resin solution was 100 KOHmg/g, and the weight average molecular weight was 8400. In the same manner as in Synthesis Example 1, propylene glycol monomethyl ether acetate was added to prepare a resin (A-3) solution (solid content concentration 40% by mass) of Synthesis Example 3.

<Synthesis Example 4>

To a flask equipped with a stirring device, a dropping funnel, a condenser, a thermometer, and a gas introduction tube, propylene glycol monomethyl ether acetate 226 g was added as a solvent, and the flask was stirred while being replaced with nitrogen gas, and the temperature was raised to 70°C.

Then, tricyclodecanyl methacrylate 22.0 g (0.1 mol), methyl methacrylate 50.0 g (0.5 mol), methacrylic acid 21.5 g (0.25 mol), and 2-isocyanatoethyl methacrylate and ε-capro To a monomer mixture consisting of 40.2 g (0.15 mol) of the reaction product of lactam, 13.0 g of 2,2'-azobis(2,4-dimethylvaleronitrile) (polymerization initiator, manufactured by Wako Pure Chemical Industries, Ltd., V-65) The addition was prepared separately. The mixture of this monomer and a polymerization initiator was dripped into the flask over 2 hours from a dropping funnel. After completion of the dropwise addition, the mixture was stirred at 70° C. for 2 hours and copolymerized to obtain a solution of the resin (A). This resin is referred to as "resin (A-4)". The acid value of the resin (A-4) contained in this resin solution was 85 KOHmg/g, and the weight average molecular weight was 8800. In the same manner as in Synthesis Example 1, propylene glycol monomethyl ether acetate was added to prepare a resin (A-4) solution (solid content concentration 40% by mass) of Synthesis Example 4.

<Synthesis Example 5>

As a mixture of a monomer and a polymerization initiator, tricyclodecanyl methacrylate 41.8 g (0.19 mol), benzyl methacrylate 24.6 g (0.14 mol), methacrylic acid 57.6 g (0.67 mol) and t-butylperoxy-2 -Ethylhexanoate (polymerization initiator, manufactured by Nichiyu Corporation, Perbutyl (registered trademark) O) Using a mixture consisting of 12.4 g, the addition amount of glycidyl methacrylate was changed to 42.6 g (0.3 mol) Except it, it carried out similarly to Synthesis Example 1, and obtained the solution of resin (A). This resin is referred to as "resin (A-5)". The acid value of the resin (A-5) contained in this resin solution was 124 KOHmg/g, the weight average molecular weight was 10000 and the unsaturated group equivalent was 600. In the same manner as in Synthesis Example 1, propylene glycol monomethyl ether acetate was added to prepare a resin (A-5) solution (solid content concentration 40% by mass) of Synthesis Example 5.

<Synthesis Example 6>

As a mixture of a monomer and a polymerization initiator, tricyclodecanyl methacrylate 52.8 g (0.24 mol), ethoxylated o-phenylphenol acrylate 53.6 g (0.2 mol), methacrylic acid 48.2 g (0.56 mol) and t-butyl A mixture consisting of 5.7 g of peroxy-2-ethylhexanoate (polymerization initiator, manufactured by Nichiyu Corporation, Perbutyl (registered trademark) O) was used, and the amount of glycidyl methacrylate added was 24.1 g (0.17 mol). Except having changed to, it carried out similarly to Synthesis Example 1, and obtained the solution of resin (A). This resin is referred to as "resin (A-6)". The acid value of the resin (A-6) contained in this resin solution was 125 KOHmg/g, the weight average molecular weight was 9200, and the unsaturated group equivalent was 1100. In the same manner as in Synthesis Example 1, propylene glycol monomethyl ether acetate was added to prepare a resin (A-6) solution (solid content concentration of 40% by mass) of Synthesis Example 6.

<Synthesis Example 7>

Resin (A) in the same manner as in Synthesis Example 2 except that the addition amount of t-butylperoxy-2-ethylhexanoate (polymerization initiator, manufactured by Nichiyu Corporation, Perbutyl (registered trademark) O) was changed to 4.7 g. To obtain a solution of. This resin is referred to as "resin (A-7)". The acid value of the resin (A-7) contained in this resin solution was 65 KOHmg/g, the weight average molecular weight was 15000, and the unsaturated group equivalent was 600.

<Synthesis Example 8>

Resin (A) in the same manner as in Synthesis Example 2 except that the addition amount of t-butylperoxy-2-ethylhexanoate (polymerization initiator, manufactured by Nichiyu Corporation, Perbutyl (registered trademark) O) was changed to 2.3 g. To obtain a solution of. This resin is referred to as "resin (A-8)". The acid value of the resin (A-8) contained in this resin solution was 65 KOHmg/g, the weight average molecular weight was 30000, and the unsaturated group equivalent was 600.

<Synthesis Example 9>

As a mixture of a monomer and a polymerization initiator, tricyclodecanyl methacrylate 39.6 g (0.18 mol), methyl methacrylate 57.0 g (0.57 mol), methacrylic acid 7.7 g (0.09 mol), glycidyl methacrylate 22.7 A solution of the resin (A) was obtained in the same manner as in Synthesis Example 3, except that a mixture consisting of g (0.16 mol) and 14.0 g of azobisisobutyronitrile was used. This resin is referred to as "resin (A-9)". The acid value of the resin (A-9) contained in this resin solution was 30 KOHmg/g, and the weight average molecular weight was 8500.

<Synthesis Example 10>

As a mixture of a monomer and a polymerization initiator, tricyclodecanyl methacrylate 22.0 g (0.1 mol), methyl methacrylate 42.0 g (0.42 mol), 2-ethylhexyl acrylate 11.0 g (0.06 mol), methacrylic acid 22.4 g (0.26 mol), glycidyl methacrylate 22.7 g (0.16 mol), and azobisisobutyronitrile 13.2 g, except for using a mixture consisting of the same procedure as in Synthesis Example 3 to obtain a solution of the resin (A). This resin is referred to as "resin (A-10)". The acid value of the resin (A-10) contained in this resin solution was 100 KOHmg/g, and the weight average molecular weight was 8700.

<Comparative Synthesis Example 1>

(1) Preparation of copolymer

A monomer mixture consisting of 64.1 g of N-phenylmaleimide, 18.8 g of methacrylic acid, 10.3 g of glycidyl methacrylate and 6.8 g of styrene, 300 g of propylene glycol monomethyl ether acetate as a solvent, and 2,2' as a radical polymerization initiator -2 g of azobis (2,4-dimethylvaleronitrile) was placed in a 500 ml round bottom flask equipped with a reflux condenser and a stirrer. The temperature was raised to 70° C., and the mixture was stirred for 5 hours for polymerization to form a copolymer. The acid value of the copolymer thus produced was 80 KOHmg/g, and the weight average molecular weight was 11000.

(2) compounds having a xanthene skeleton structure

125.4 g of spiro[fluorene-9,9'-xanthene]-3',6'-diol and 0.1386 g of t-butylammonium bromide were placed in a 3000 ml round bottom flask and mixed. 78.6 g of epichlorohydrin was further added, and the mixture was heated to 90°C to react. After confirming complete consumption of spiro[fluorene-9,9'-xanthene]-3',6'-diol by liquid chromatography analysis, the reaction mass was cooled to 30° C. and 50% NaOH aqueous solution (3 equivalents ) Was added slowly. After confirming complete consumption of epichlorohydrin by liquid chromatography analysis, the reactant was extracted using dichloromethane and washed three times. The organic layer was dried over magnesium sulfate, and dichloromethane was distilled off under reduced pressure. The crude product was crystallized using a mixture solvent of dichloromethane and methanol (50:50, v/v).

0.004 equivalents of t-butylammonium bromide, 0.001 equivalents of 2,6-diisobutylphenol, and 2.2 equivalents of acrylic acid were added to 1 equivalent of the epoxy-based compound thus obtained. Then, 8.29 g of propylene glycol monomethyl ether acetate was further added and mixed. Air was blown into the solution thus prepared at 25 ml/min, and the solution was heated to 90 to 100°C to dissolve the reactant. When the solution was white and cloudy, the temperature was raised to 120° C. to completely dissolve the reactant. When the solution became clear and the viscosity increased, the acid value of the solution was measured, and the solution was stirred until the acid value became less than 1.0 KOHmg/g. Stirring was continued for 11 hours until the acid value reached the target value (0.8 KOHmg/g). After completion of the reaction, the temperature of the reactor was lowered to room temperature, and a colorless transparent solid was obtained.

43 g of the thus obtained solid product, 33.6 g of acrylic acid, 0.04 g of 2,6-di-t-butyl-p-cresol, 0.21 g of tetrabutyl ammonium acetate, and 18 g of propylene glycol monomethyl ether acetate were placed in a reaction flask, The mixture was stirred at 120°C for 13 hours. Then, the reaction body was cooled to room temperature, 24 g of propylene glycol monomethyl ether acetate and 10 g of succinic anhydride were added, and the mixture was then stirred at 100°C for 3 hours. 8 g of bisphenol Z glycidyl ether was further added to the mixture, and the mixture was stirred at 120°C for 4 hours, 90°C for 3 hours, 60°C for 2 hours, and 40°C for 5 hours. Reprecipitation with water and alcohol was performed to obtain the final resin in the form of a powder. Next, propylene glycol monomethyl ether acetate was added so that the solid content concentration became 48 mass%. The acid value of the resin thus obtained was 105 KOHmg/g, and the weight average molecular weight was 5500.

The copolymer obtained in (1) and the compound having a xanthene skeleton structure obtained in (2) were mixed so as to have a solid content ratio of 6:4 to prepare a resin solution of Comparative Synthesis Example 1.

<Measurement method of physical property values>

The acid value, the unsaturated group equivalent, and the weight average molecular weight described in the synthesis example are values obtained by the method described below.

(1) Acid value: It is the acid value of resin (A) measured using the 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 resin (A).

(2) Unsaturated group equivalent: This is the mass of the polymer per mole of polymerizable unsaturated bonds, and is a calculated value calculated based on the amount of monomer used.

(3) Weight average molecular weight (Mw): It means the weight average molecular weight in terms of standard polystyrene measured under the following conditions using gel permeation chromatography (GPC).

Column: Shodex (registered trademark) LF-804+LF-804 (made by Showa Denko Corporation)

Column temperature: 40 °C

Sample: 0.2% tetrahydrofuran solution of the copolymer

Development solvent: tetrahydrofuran

Detector: Differential refractometer (Shōdex (registered trademark) RI-71S) (manufactured by Showa Denko Corporation)

Flow rate: 1 ml/min

<Examples 1, 2, 5 to 8, Reference Examples 3, 4, 9, 10 and Comparative Examples 1 to 2>

Using the resin solution of Synthesis Examples 1 to 10 and Comparative Synthesis Example 1 and a commercially available resin solution, Examples 1, 2, 5 to 8, and Reference Example 3, according to the formulation (based on mass%) of Tables 1 and 2 below. The photosensitive resin composition for forming a black column spacer of 4, 9, 10 and Comparative Examples 1-2 was prepared. Comparative Example 1 is an example corresponding to Patent Document 2. In addition, in the following formulation, the solvent used at the time of preparation is not included in the amount of the resin (A). The amount of the solvent contained in the solution of the resin (A) is added up in the solvent (B) as a compounding component. In Tables 1 and 2, V259ME is a propylene glycol monomethyl ether acetate solution of a fluorene-type epoxy-type acrylate/acid anhydride polymerization adduct (56.5 mass%, such as a resin component), Synnittetsu Chemical Co., Ltd. V259ME, and PGMEA, Propylene glycol monomethyl ether acetate, OXE 01 is 1.2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)], IRGACURE OXE 01 manufactured by BASF, and mill base 1 is , A mill base containing a lactam-based organic black (manufactured by BASF) and a pigment concentration of 18 mass%, a mill base 2 having a mill base containing carbon black and a pigment concentration of 25 mass%, and DPHA is dipentaerythritol Hexaacrylate is A-DPH manufactured by Shin-Nakamura Industries, Ltd., and KBM-403 is 3-glycidoxypropyltriethoxysilane, and KBM-403 manufactured by Shin-Etsu Silicone.

<Evaluation of colorant dispersibility>

The colorant dispersibility was evaluated by the method shown below.

First, the photosensitive resin composition for forming a black column spacer of Examples 1, 2, 5 to 8, Reference Examples 3, 4, 9, 10, and Comparative Examples 1 to 2 was coated on an IZO substrate having a thickness of 10 cm x 10 cm. It was spin-coated so that it might become 1.5 micrometers. Thereafter, the solvent was volatilized by heating at 90° C. for 3 minutes. Next, the entire surface of the coating film was exposed (exposure amount 50 mJ/cm 2) and photocured using the Ushio Electric Co., Ltd. multi-light ML-251D/B and irradiation optical unit PM25C-100. Then, it developed for 120 seconds with 0.2 mass% of potassium hydroxide aqueous solution, and it further post-baked at 230 degreeC for 30 minutes, and obtained the target cured coating film. By using a transmission densitometer (361T, X-lite), the optical density (Optical Density: OD) of the cured coating film having a thickness of 1 μm was measured. The results are shown in Table 2. It can be said that the higher the optical density, the better the dispersibility of the colorant.

<Evaluation of phenomena margin>

A coating film having a thickness of 2.5 µm was prepared on the substrate by the same method as the optical density, and the reduction rate of the coating film thickness between 100 seconds and 150 seconds of development time was measured using a stylus type step meter T4000M manufactured by Kosaka Research Institute. The results are shown in Table 2. It can be said that the larger the reduction rate of the coating film thickness, the better the development margin is.

<Evaluation of solvent resistance>

The black column spacer sample used for the evaluation of the optical density was peeled off from the substrate, cut into 1 cm x 1 cm size, placed in a glass bottle containing 5 ml of N-methylpyrrolidone, and left in an oven at 100° C. for 15 minutes After that, the presence or absence of discoloration was evaluated according to the following criteria. The results are shown in Table 2.

○: When observed with the naked eye, there is no discoloration at all

X: When observed with the naked eye, discoloration is very much

<Evaluation of elastic recovery rate>

The black column spacer prepared in the evaluation of the development margin was measured at 25° C. by using an elasticity measuring device (DUH-W201S, 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 as a load-unloading method. The elastic recovery rate was measured by a test in which a load of 300 mN was applied to obtain discernable results between the compared groups. The load speed of 3 gf/second and the holding time of 3 seconds were kept constant. Regarding the elastic recovery rate, a load was constantly applied to the flat pressurized body for 3 seconds, and then the actual elastic recovery rate of the pattern before and after the load was measured by using a three-dimensional thickness measuring device. The elastic recovery rate means the ratio of the distance recovered after the lapse of the recovery time of 10 minutes to the compressed distance (compression displacement) when a constant force is applied, and it is expressed by the following equation.

Elasticity recovery rate (%) ＝ [(Recovery distance/compression displacement) × 100]

The results are shown in Tables 3 and 4.

From the above results, the photosensitive resin compositions for forming black column spacers of Examples 1, 2, 5 to 8 and Reference Examples 3, 4, 9, and 10 are excellent in colorant dispersibility, development margin, solvent resistance, and elastic recovery rate. On the other hand, in the photosensitive resin composition for forming a black column spacer of Comparative Example 1, when a load is applied in the elastic recovery rate test, the spacer is destroyed, and physical properties as a spacer are inferior. In addition, the photosensitive resin composition for forming a black column spacer of Comparative Example 2 resulted in a large amount of discoloration in the evaluation of solvent resistance.

Claims (12)

A resin (A) having a structural unit (a) having a carboxyl group and a structural unit (b) derived from glycidyl (meth)acrylate, a solvent (B), a photoinitiator (C), and a coloring agent (D), ,
The resin (A) further has a structural unit (c) having an aromatic ring skeleton and a structural unit (d) having a crosslinked alicyclic hydrocarbon group having 7 to 20 carbon atoms. Resin composition. The method of claim 1,
The photosensitive resin composition for forming a black column spacer, wherein the aromatic ring skeleton is at least one member selected from the group consisting of a biphenyl skeleton, a naphthalene skeleton, and an anthracene skeleton. delete The method according to claim 1 or 2,
The photosensitive resin composition for forming a black column spacer, wherein the carboxyl group is a carboxyl group derived from an unsaturated carboxylic acid, a carboxyl group derived from a polybasic acid, or a carboxyl group derived from a polybasic acid anhydride. The method according to claim 1 or 2,
The photosensitive resin composition for forming a black column spacer, wherein the resin (A) has an equivalent weight of an unsaturated group of 200 to 2000 g/mol. The method according to claim 1 or 2,
The photosensitive resin composition for forming a black column spacer, wherein the colorant (D) contains an inorganic black pigment and an organic black pigment. The method according to claim 1 or 2,
Containing 1-20 mass% of said resin (A), 50-94 mass% of said solvent (B), 0.01-5 mass% of said photoinitiator (C), and 3-30 mass% of said coloring agent (D) A photosensitive resin composition for forming a black column spacer, characterized in that. The method of claim 7,
A photosensitive resin composition for forming a black column spacer, further comprising 1 to 20 mass% of a reactive diluent (E). A black column spacer obtained by curing the photosensitive resin composition for forming a black column spacer according to claim 1 or 2. An image display device comprising the black column spacer according to claim 9. delete delete