JP2011145677A - Photosensitive resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition which has proper storage stability, avoids odor annoyance, ensures proper solvent resistance and satisfactory surface smoothness of a cured resin pattern formed therefrom, does not cause coating defects, such as a granular foreign substance, has a high resolution for forming a fine pattern, and can form a photospacer with a superior recovery rate. <P>SOLUTION: The photosensitive resin composition for forming a photospacer includes a binder resin (A); a photopolymerizable compound (B); a photopolymerization initiator (C), which is a compound selected from an acetophenone compound, and so on; and a solvent (D), wherein the binder resin (A) is a copolymer prepared by copolymerizing a compound having at least one skeleton selected from tricyclodecane and dicyclopentadiene and an unsaturated bond in one molecule, a copolymerizable compound having an unsaturated bond, and a compound having an unsaturated bond and an epoxy group within a single molecule to obtain a copolymer 1, reacting the copolymer 1 with a carboxylic acid having an unsaturated bond to obtain a copolymer 2, and making the copolymer react with acid anhydride. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a photosensitive resin composition.

A spacer is provided between the color filter constituting the display device, such as a liquid crystal display device or a touch panel, and the array substrate in order to maintain the distance between the two substrates. Conventionally, spherical particles such as glass beads and plastic beads are used as the spacer.
However, when such spherical particles are used, the liquid crystal display element is scattered randomly on the glass substrate. If the TFT element or the electrode is damaged or exists in the transmissive pixel portion, the liquid crystal display element is scattered due to scattering of incident light. In some cases, the contrast of the image was lowered. Therefore, it has been proposed to form a spacer using a photosensitive resin composition instead of spraying spherical particles. By this method, since the spacer can be formed at an arbitrary place, the above-mentioned problems can be solved. As such a photosensitive resin composition, conventionally, a spacer forming composition containing a binder resin made of an acrylic copolymer having a carboxyl group and an epoxy group is known, and an epoxy is used during post-baking after development. A spacer pattern excellent in solvent resistance and heat resistance can be obtained by crosslinking between a group and a carboxyl group (Patent Document 1).
Further, a spacer forming composition containing a radiation-sensitive curable resin having a (meth) acryloyl group and a carboxyl group is known as a spacer forming composition (Patent Document 2).

JP-A-11-133600, page 2, left column, line 2-page 2, left column, line 9 JP, 2002-20442, page 2 left column 2 line 3 page left column 6 line

However, although the spacer formed by the composition described in Patent Document 1 has good performance after formation, it is important to note that if the composition is stored for a long period of time, thickening or gelation will occur. The inventor found.
In addition, in the radiation-sensitive curable resin described in Patent Document 2, an isocyanate compound is used when a (meth) acryloyl group is introduced, and the resulting radiation-sensitive curable resin, and further a spacer using the isocyanate compound The inventor has also found that there is an odor problem due to isocyanate compounds when handling the forming composition.

  An object of the present invention is to provide a photosensitive resin composition having good storage stability and no odor problem, and having a solvent resistance of a cured resin pattern formed using the photosensitive resin composition of the present invention. Photosensitive resin that is good, has excellent surface smoothness, does not cause coating defects such as granular foreign matter, can be resolved to fine patterns, and can form a pattern like a photo spacer with excellent recovery rate An object is to provide a composition.

As a result of intensive studies on new means that can solve the above-mentioned problems, the present inventors have found that a photosensitive resin composition containing a specific resin and a specific photopolymerization initiator can solve the above-mentioned problems. Invented.
That is, the present invention relates to a photosensitive resin composition containing a binder resin (A), a photopolymerizable compound (B), a photopolymerization initiator (C), and a solvent (D).
The binder resin (A) is obtained by copolymerizing the following (A1), (A2) and (A4) to obtain a copolymer 1, and the obtained copolymer 1 and (A3) are combined into the copolymer 1. The copolymer 2 is obtained by reacting at the site of the epoxy group derived from (A4), and the obtained copolymer 2 and (A5) are further reacted with (A4) and (A3) of the copolymer 1 The photopolymerization initiator (C) is a copolymer obtained by reacting with a hydroxyl group produced by the above, at least selected from the group consisting of acetophenone compounds, biimidazole compounds, oxime compounds and triazine compounds. A photosensitive resin composition that is a kind of compound and is used for forming a photospacer is provided.
(A1); Compound (A2) having at least one skeleton selected from the group consisting of a tricyclodecane skeleton and a dicyclopentadiene skeleton and an unsaturated bond in one molecule; and (A1) and (A4) Compound (A3) having polymerizable unsaturated bond; Carboxylic acid (A4) having unsaturated bond; Compound (A5) having unsaturated bond and epoxy group in one molecule; Acid anhydride provided that (A1) ~ (A5) are not the same.

  Moreover, this invention is formed using the pattern formed using the said photosensitive resin composition, the photo spacer formed using the said photosensitive resin composition, and the said photosensitive resin composition. Insulating film, overcoat formed using the photosensitive resin composition, pattern, photospacer, insulating film, overcoat, and liquid crystal alignment control protrusion formed using the photosensitive resin composition A color filter comprising at least one structure selected from the group consisting of: and a display device comprising the color filter.

  The photosensitive resin composition of the present invention has good storage stability, no odor problem, the formed coating film or pattern has good solvent resistance, excellent surface smoothness, particulate foreign matter, etc. A coating defect does not occur, it is possible to resolve a fine pattern, and it is suitable for leaving a pattern like a photo spacer.

  Hereinafter, the present invention will be described in detail.

  In the photosensitive resin composition of the present invention, the binder resin (A), the photopolymerizable compound (B), the photopolymerization initiator (C), and optionally other additives (E) are dissolved in the solvent (D). Or distributed.

The binder resin (A) has reactivity and alkali solubility due to the action of light and heat. The binder resin (A) used in the photosensitive resin composition of the present invention is obtained by copolymerizing the following (A1), (A2) and (A4) to obtain a copolymer 1, and the obtained copolymer 1 and (A3) are reacted at the site of the epoxy group derived from (A4) of copolymer 1 to obtain copolymer 2, and the obtained copolymer 2 and (A5) are copolymerized. This is a copolymer obtained by reacting with the site of the hydroxyl group produced by the reaction of (A4) and (A3) of the coalescence 1.
(A1); Compound (A2) having at least one skeleton selected from the group consisting of a tricyclodecane skeleton and a dicyclopentadiene skeleton and an unsaturated bond in one molecule; and (A1) and (A4) Compound (A3) having polymerizable unsaturated bond; Carboxylic acid (A4) having unsaturated bond; Compound (A5) having unsaturated bond and epoxy group in one molecule; Acid anhydride provided that (A1) -(A5) are not mutually the same.

  As the compound (A1) having an unsaturated bond, at least one skeleton selected from the group consisting of a tricyclodecane skeleton and a dicyclopentadiene skeleton in one molecule, and an unsaturated bond, specifically, dicyclo Examples include pentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, and dicyclopentenyloxyethyl (meth) acrylate. These can be used alone or in combination. Here, description of (meth) acrylate in this specification represents an acrylate and / or a methacrylate.

Specific examples of the compound (A2) having an unsaturated bond copolymerizable with (A1) and (A4) include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-hydroxy Unsubstituted or substituted alkyl esters of unsaturated carboxylic acids such as ethyl (meth) acrylate and aminoethyl (meth) acrylate;
Cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, cycloheptyl (meth) acrylate, cyclooctyl (meth) acrylate, menthyl (meth) acrylate, cyclopentenyl (meth) acrylate, cyclohexenyl (meta) ) Acrylate, cycloheptenyl (meth) acrylate, cyclooctenyl (meth) acrylate, mentadienyl (meth) acrylate, isobornyl (meth) acrylate, pinanyl (meth) acrylate, adamantyl (meth) acrylate, norbornenyl (meth) acrylate, pinenyl (meth) acrylate An ester compound containing an alicyclic group of an unsaturated carboxylic acid such as
Monosaturated carboxylic acid ester compounds of glycols such as oligoethylene glycol monoalkyl (meth) acrylate;
Ester compounds containing an aromatic ring of an unsaturated carboxylic acid such as benzyl (meth) acrylate and phenoxy (meth) acrylate;
Aromatic vinyl compounds such as styrene, α-methylstyrene, α-phenylstyrene and vinyltoluene;
Carboxylic acid vinyl esters such as vinyl acetate and vinyl propionate;
Vinyl cyanide compounds such as (meth) acrylonitrile and α-chloroacrylonitrile;
And N-substituted maleimide compounds such as N-cyclohexylmaleimide, N-phenylmaleimide, and N-benzylmaleimide. These can be used alone or in combination.

  Specific examples of the carboxylic acid (A3) having an unsaturated bond include acrylic acid and methacrylic acid. Acrylic acid and methacrylic acid can be used alone or in combination. In addition to these acrylic acid and methacrylic acid, other carboxylic acids having an unsaturated group can be used. Specific examples of other carboxylic acid having an unsaturated group include crotonic acid, itaconic acid, maleic acid, and fumaric acid. In addition, a carboxylic acid having an unsaturated group containing a hydroxy group and a carboxyl group in the same molecule, such as α- (hydroxymethyl) acrylic acid, can be used in combination.

  As the compound (A4) having an unsaturated bond and an epoxy group in one molecule, glycidyl (meth) acrylate, (meth) acrylic acid-β-methylglycidyl, (meth) acrylic acid-β-ethylglycidyl, ( (Meth) acrylic acid-β-propylglycidyl, α-ethylacrylic acid-β-methylglycidyl, (meth) acrylic acid-3-methyl-3,4-epoxybutyl, (meth) acrylic acid-3-ethyl-3, Examples include 4-epoxybutyl, (meth) acrylic acid-4-methyl-4,5-epoxypentyl, (meth) acrylic acid-5-methyl-5,6-epoxyhexyl, and glycidyl vinyl ether. ) Glycidyl acrylate.

  The acid anhydride (A5) is a compound having one acid anhydride group in the molecule, specifically, maleic acid anhydride, succinic acid anhydride, itaconic acid anhydride, phthalic acid anhydride, tetrahydrophthalic acid. Examples of the acid anhydride include hexahydrophthalic anhydride, methyl endomethylenetetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, trimellitic anhydride, and the like. Tetrahydrophthalic anhydride is preferable.

  The binder resin (A) used in the present invention is obtained by copolymerizing (A1), (A2) and (A4) to obtain a copolymer 1, and the obtained copolymer 1 and (A3) It is a copolymer obtained by reacting to obtain a copolymer 2, and further reacting the obtained copolymer 2 with (A5).

First, in order to obtain the copolymer 1, (A1), (A2) and (A4) are copolymerized.
This copolymerization is performed under ordinary conditions. For example, in a flask equipped with a stirrer, a thermometer, a reflux condenser, a dropping funnel and a nitrogen introduction tube, 0.5 to 0.5 on a mass basis with respect to the total amount of (A1), (A2) and (A4). A 20-fold amount of solvent is introduced, and the atmosphere in the flask is replaced with nitrogen from air. Then, after heating up a solvent to 40-140 degreeC, it is a mass reference | standard with respect to the predetermined amount of (A1), (A2) and (A4), and the total amount of (A1), (A2) and (A4). 0 to 20 times the amount of solvent, and a polymerization initiator such as azobisisobutyronitrile and benzoyl peroxide are added in an amount of 0.1 to the total number of moles of (A1), (A2) and (A4). A solution added with 10 mol% (stirred and dissolved at room temperature or under heating) is dropped from the dropping funnel into the flask over 0.1 to 8 hours, and further stirred at 40 to 140 ° C. for 1 to 10 hours.
In the above step, a part or the whole amount of the polymerization initiator may be charged to the flask side, and a part or the whole amount of (A1), (A2) and (A4) may be charged to the flask side. Moreover, in order to control molecular weight and molecular weight distribution, you may use (alpha) -methylstyrene dimer and a mercapto compound as a chain transfer agent. The usage-amount of (alpha) -methylstyrene dimer and a mercapto compound is 0.005 to 5% on a mass basis with respect to the total amount of (A1)-(A3). In addition, the above-described polymerization conditions may be appropriately adjusted in the preparation method and the reaction temperature in consideration of the production equipment, the amount of heat generated by the polymerization, and the like.

  The ratio of the component derived from each is preferably in the following range in terms of a mole fraction with respect to the total number of moles of the component constituting the copolymer 1.

Structural units derived from (A1); 2 to 40 mol%
Structural units derived from (A2); 2 to 95 mol%
Structural units derived from (A4); 3 to 65 mol%

Moreover, it is more preferable in the ratio of the said structural component being the following ranges.

Structural units derived from (A1); 5-35 mol%
Structural units derived from (A2); 5 to 80 mol%
Structural units derived from (A4); 15-60 mol%

  When the composition ratio is in the above range, the balance between flexibility and heat resistance is good, and a preferable trunk polymer is obtained.

  Next, (A3) is added to the copolymer 1 to impart light / thermosetting properties to the binder resin (A).

  Reaction of the copolymer 1 and (A3) can be performed on the conditions as described in Unexamined-Japanese-Patent No. 2001-89533, for example. Specifically, the atmosphere in the flask is replaced with air from nitrogen, and 5 to 100 mol% of (A3), carboxyl with respect to the structural unit derived from (A4) of the copolymer 1 As a reaction catalyst for a group and an epoxy group, for example, trisdimethylaminomethylphenol is 0.01 to 5% on a mass basis with respect to the total amount of (A1) to (A4), and as a polymerization inhibitor, for example, By adding 0.001 to 5% in a flask on a mass basis with respect to the total amount of (A1) to (A4), the hydroquinone is reacted at 60 to 130 ° C. for 1 to 10 hours. Copolymer 1 and (A3) can be reacted. Similar to the polymerization conditions, the charging method and the reaction temperature may be appropriately adjusted in consideration of the production equipment, the amount of heat generated by the polymerization, and the like.

The amount of (A3) added is 5 to 100 mol%, preferably 5 to 100 mol%, based on the epoxy group (derived from the A4 component) in the resin obtained by copolymerizing (A1), (A2) and (A4). 10 to 95 mol%.
It is preferable that the composition ratio of (A4) is in the above range because sufficient photocurability and thermosetting can be obtained and the reliability is excellent.

  Next, the copolymer 2 and (A5) are reacted to impart alkali solubility to the binder resin (A).

  The reaction between the copolymer 2 and (A5) can be performed, for example, under the conditions described in JP-A-2001-89533. Specifically, with respect to the structural unit derived from (A3) of the copolymer 2, (A5) having a molar fraction of 5 to 100 mol%, for example, triethylamine is used as the reaction catalyst (A1) to With respect to the total amount of (A4), 0.01 to 5% is put in a flask on a mass basis and reacted at 60 to 130 ° C. for 1 to 10 hours. A5) can be reacted. Similar to the polymerization conditions, the charging method and the reaction temperature may be appropriately adjusted in consideration of the production equipment, the amount of heat generated by the polymerization, and the like.

  The addition amount of (A5) is 5 to 100 mol%, preferably 10 to 95 mol%, based on the number of moles of the alcoholic hydroxyl group of copolymer 2 (derived from component A3).

  The weight average molecular weight in terms of polystyrene of the binder resin (A) is preferably 3,000 to 100,000, more preferably 5,000 to 30,000. When the weight average molecular weight of the binder resin (A) is within the above range, the coating property is good, the film is not easily reduced during development, and the unexposed part tends to be easily removed during development. ,preferable.

  The molecular weight distribution [weight average molecular weight (Mw) / number average molecular weight (Mn)] of the binder resin (A) is preferably 1.5 to 6.0, and more preferably 1.8 to 4.0. The molecular weight distribution in the above range is preferable because the developability is excellent.

  Content of binder resin (A) used for the photosensitive resin composition of this invention is a mass fraction with respect to solid content of the photosensitive resin composition, and is 5-90 mass% normally, Preferably it is 10-70. % By mass. When the content of the binder resin (A) is in the above range, the solubility in the developer is sufficient, development residue is hardly generated on the unexposed part of the substrate, and the film thickness of the exposed part is reduced during development. This is preferable because the non-exposed portion tends to be easily removed.

  As in the present invention, the binder resin having a (meth) acryl group introduced into the side chain of the binder resin, in addition to the binder resin (A) of the present invention, a binder resin having a carboxyl group, and in one molecule There is a type in which an epoxy group and a compound containing a (meth) acryl group are reacted. In this type, in order to increase the content of (meth) acrylic groups in the side chain, a binder resin having a high carboxyl group ratio must be used. However, a binder resin having a high carboxyl group ratio has a high solution viscosity, which causes problems in synthesis and handling. Since the present invention uses a trunk polymer that does not contain a carboxyl group, there is no problem as described above.

The photopolymerizable compound (B) contained in the photosensitive resin composition of the present invention can be a bifunctional or other polyfunctional monomer in addition to a monofunctional monomer.
Specific examples of the monofunctional monomer include nonylphenyl carbitol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-ethylhexyl carbitol acrylate, 2-hydroxyethyl acrylate, N-vinyl pyrrolidone and the like.
Specific examples of the bifunctional monomer include 1,6-hexanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, and bisphenol A. Bis (acryloyloxyethyl) ether, 3-methylpentanediol di (meth) acrylate, and the like.
Specific examples of other polyfunctional monomers include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa ( Examples thereof include a reaction product of meth) acrylate, pentaerythritol tri (meth) acrylate and an acid anhydride, a reaction product of dipentaerythritol penta (meth) acrylate and an acid anhydride, and the like. Of these, polyfunctional monomers having two or more functions are preferably used.
The content of the photopolymerizable compound (B) is preferably 1 to 70 parts by mass with respect to 100 parts by mass in total of the binder resin (A) and the photopolymerizable compound (B) in the photosensitive resin composition. Preferably it is 5-60 mass parts. When the content of the photopolymerizable compound (B) is within the above range, the strength, smoothness and reliability of the structure formed using the composition tend to be favorable, which is preferable.

  As the photopolymerization initiator (C) contained in the photosensitive resin composition of the present invention, an acetophenone compound, a biimidazole compound, an oxime compound, a triazine compound, or a mixture thereof is used. By using the photopolymerization initiator and the photopolymerization initiation aid (C-1) in combination, the photosensitive resin composition becomes more sensitive, and the productivity when forming a pattern using this is improved. Therefore, it is preferable. However, when the absorption wavelength of the photopolymerization initiator auxiliary agent (C-1) is on the longer wavelength side than the absorption wavelength of the photopolymerization initiator (C), the transmittance of the formed film is lowered, so the effect of the present invention Can be used as long as it does not damage the surface.

  Examples of the acetophenone compound include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 2-hydroxy-1- [4- (2-hydroxyethoxy) phenyl]. 2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- Specific examples of (4-morpholinophenyl) butan-1-one and acetophenone include 2- (2-methylbenzyl) -2-dimethylamino-1- (4-morpholinophenyl) -butanone, 2- ( 3-methylbenzyl) -2-dimethylamino-1- (4-morpholinophenyl) -butanone, -(4-methylbenzyl) -2-dimethylamino-1- (4-morpholinophenyl) -butanone, 2- (2-ethylbenzyl) -2-dimethylamino-1- (4-morpholinophenyl) -butanone, 2 -(2-propylbenzyl) -2-dimethylamino-1- (4-morpholinophenyl) -butanone, 2- (2-butylbenzyl) -2-dimethylamino-1- (4-morpholinophenyl) -butanone, 2 -(2,3-dimethylbenzyl) -2-dimethylamino-1- (4-morpholinophenyl) -butanone, 2- (2,4-dimethylbenzyl) -2-dimethylamino-1- (4-morpholinophenyl) -Butanone, 2- (2-chlorobenzyl) -2-dimethylamino-1- (4-morpholinophenyl) -butanone, 2- (2-bromobenze ) -2-dimethylamino-1- (4-morpholinophenyl) -butanone, 2- (3-chlorobenzyl) -2-dimethylamino-1- (4-morpholinophenyl) -butanone, 2- (4-chlorobenzyl) ) -2-dimethylamino-1- (4-morpholinophenyl) -butanone, 2- (3-bromobenzyl) -2-dimethylamino-1- (4-morpholinophenyl) -butanone, 2- (4-bromobenzyl) ) -2-dimethylamino-1- (4-morpholinophenyl) -butanone, 2- (2-methoxybenzyl) -2-dimethylamino-1- (4-morpholinophenyl) -butanone, 2- (3-methoxybenzyl) ) -2-Dimethylamino-1- (4-morpholinophenyl) -butanone, 2- (4-methoxybenzyl) -2-dimethylamino-1- ( 4-morpholinophenyl) -butanone, 2- (2-methyl-4-methoxybenzyl) -2-dimethylamino-1- (4-morpholinophenyl) -butanone, 2- (2-methyl-4-bromobenzyl)- 2-dimethylamino-1- (4-morpholinophenyl) -butanone, 2- (2-bromo-4-methoxybenzyl) -2-dimethylamino-1- (4-morpholinophenyl) -butanone, 2-hydroxy-2 -Methyl-1- [4- (1-methylvinyl) phenyl] propan-1-one oligomer and the like.

  Examples of the biimidazole compound include 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole and 2,2′-bis (2,3-dichlorophenyl) -4. , 4 ′, 5,5′-tetraphenylbiimidazole (see, for example, JP-A-6-75372 and JP-A-6-75373), 2,2′-bis (2-chlorophenyl) -4, 4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetra (alkoxyphenyl) biimidazole, 2,2′-bis ( 2-chlorophenyl) -4,4 ′, 5,5′-tetra (dialkoxyphenyl) biimidazole, 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetra (trialkoxy) Phenyl) biimidazole (for example, see JP-B-48-38403, JP-A-62-174204, etc.), and the phenyl group at the 4,4′5,5′-position is substituted with a carboalkoxy group. Imidazole compounds (see, for example, JP-A-7-10913) and the like, preferably 2,2′-bis (2-chlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole, 2,2′-bis (2,3-dichlorophenyl) -4,4 ′, 5,5′-tetraphenylbiimidazole may be mentioned.

  Examples of the oxime compound include O-ethoxycarbonyl-α-oximino-1-phenylpropan-1-one, a compound represented by formula (a), a compound represented by formula (b), and the like.

  Examples of the triazine compound include 2,4-bis (trichloromethyl) -6- (4-methoxyphenyl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- (4- Methoxynaphthyl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6-piperonyl-1,3,5-triazine, 2,4-bis (trichloromethyl) -6- (4-methoxy Styryl) -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- [2- (5-methylfuran-2-yl) ethenyl] -1,3,5-triazine, 2,4 -Bis (trichloromethyl) -6- [2- (furan-2-yl) ethenyl] -1,3,5-triazine, 2,4-bis (trichloromethyl) -6- [2- (4-diethylamino- 2-methylphenyl) Thenyl] -1,3,5-triazine, such as 2,4-bis (trichloromethyl) -6- [2- (3,4-dimethoxyphenyl) ethenyl] -1,3,5-triazine.

In addition, a photopolymerization initiator or the like commonly used in this field can be used in combination as long as the effect of the present invention is not impaired. For example, benzoin compounds, benzophenone compounds, thioxanthone compounds, anthracene And photopolymerization initiators such as a series compound.
More specifically, the following compounds can be mentioned, and these can be used alone or in combination of two or more.

  Examples of the benzoin-based compound include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

  Examples of the benzophenone compounds include benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4′-methyldiphenyl sulfide, 3,3 ′, 4,4′-tetra (tert-butyl). Peroxycarbonyl) benzophenone, 2,4,6-trimethylbenzophenone, and the like.

  Examples of the thioxanthone compound include 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, and the like.

  Examples of the anthracene compound include 9,10-dimethoxyanthracene, 2-ethyl-9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, and 2-ethyl-9,10-diethoxyanthracene. It is done.

  In addition, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 10-butyl-2-chloroacridone, 2-ethylanthraquinone, benzyl, 9,10-phenanthrenequinone, camphorquinone, methyl phenylglyoxylate A photopolymerization initiator such as a titanocene compound can be used in combination.

Moreover, what is described in Tokushu 2002-544205 gazette can be used together as a photoinitiator which has the group which can raise | generate a chain transfer.
As a photoinitiator which has the group which can raise | generate the said chain transfer, the thing of following formula (2)-(7) is mentioned, for example.

  The photopolymerization initiator having a group capable of causing chain transfer can be used as the constituent component (A2) of the copolymer 1. And binder resin (A) obtained using (A2) can be used together with the binder resin of this invention.

In addition, the photopolymerization initiator may be used in combination with a photopolymerization initiation assistant (C-1). As the photopolymerization initiation assistant, an amine compound and the following carboxylic acid compound are preferable, and the amine compound is more preferably an aromatic amine compound. However, when the absorption wavelength of the photopolymerization initiator auxiliary agent (C-1) is on the longer wavelength side than the absorption wavelength of the photopolymerization initiator (C), the transmittance of the formed film is lowered, and thus the effect of the present invention. Can be used as long as it does not damage the surface.
Specific examples of the photopolymerization initiation aid include aliphatic amine compounds such as triethanolamine, methyldiethanolamine, triisopropanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, 4-dimethylaminobenzoic acid. Isoamyl, 2-dimethylhexyl 4-dimethylaminobenzoate, 2-dimethylaminoethyl benzoate, N, N-dimethylparatoluidine, 4,4′-bis (dimethylamino) benzophenone (common name: Michler's ketone), 4,4′- Examples include aromatic amine compounds such as bis (diethylamino) benzophenone.
Examples of the carboxylic acid compound include phenylthioacetic acid, methylphenylthioacetic acid, ethylphenylthioacetic acid, methylethylphenylthioacetic acid, dimethylphenylthioacetic acid, methoxyphenylthioacetic acid, dimethoxyphenylthioacetic acid, chlorophenylthioacetic acid, dichlorophenylthioacetic acid, Examples include aromatic heteroacetic acids such as N-phenylglycine, phenoxyacetic acid, naphthylthioacetic acid, N-naphthylglycine, and naphthoxyacetic acid.

The content of the photopolymerization initiator (C) is preferably 0.1 to 40 parts by mass, more preferably 1 to 30 parts with respect to 100 parts by mass in total of the binder resin (A) and the photopolymerizable compound (B). Part by mass.
Moreover, when using photoinitiator adjuvant (C-1), the content is 0.1-50 mass parts on the said reference | standard, More preferably, it is 0.1-40 mass parts.
When the content of the photopolymerization initiator (C) is in the above range, the photosensitive resin composition becomes highly sensitive, the strength of the structure formed using the photosensitive resin composition, and the structure There is a tendency that the smoothness on the surface of the film becomes good, which is preferable. In addition to the above, when the amount of the photopolymerization initiation assistant (C-1) is in the above range, the sensitivity of the obtained photosensitive resin composition is further increased, and the photosensitive resin composition is formed using the photosensitive resin composition. This is preferable because the productivity of the patterned substrate tends to be improved.

The photosensitive resin composition of the present invention contains a solvent (D). As said solvent (D), the various organic solvent currently used in the field | area of the photosensitive resin composition can be used. Specific examples thereof include ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether and ethylene glycol monobutyl ether;
Diethylene glycol dialkyl ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether and diethylene glycol dibutyl ether;
Ethylene glycol alkyl ether acetates such as methyl cellosolve acetate and ethyl cellosolve acetate;
Alkylene glycol alkyl ether acetates such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, methoxybutyl acetate and methoxypentyl acetate;
Aromatic hydrocarbons such as benzene, toluene, xylene and mesitylene;
Ketones such as methyl ethyl ketone, acetone, methyl amyl ketone, methyl isobutyl ketone and cyclohexanone;
Alcohols such as ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol and glycerin;
Esters such as ethyl 3-ethoxypropionate and methyl 3-methoxypropionate;
and cyclic esters such as γ-butyrolactone.
Among the above solvents, organic solvents having a boiling point of 100 to 200 ° C. are preferable among the above solvents from the viewpoints of coating properties and drying properties, and more preferable are alkylene glycol alkyl ether acetates, ketones, 3 -Esters such as ethyl ethoxypropionate and methyl 3-methoxypropionate, particularly preferably propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, cyclohexanone, ethyl 3-ethoxypropionate, 3-methoxy And methyl propionate.
These solvents (D) can be used alone or in admixture of two or more.
Content of the solvent (D) in the photosensitive resin composition of this invention is a mass fraction with respect to the photosensitive resin composition, and is 60-90 mass% normally, Preferably it is 70-85 mass%. When the content of the solvent (D) is within the above range, when applied by a spin coater, slit & spin coater, slit coater (sometimes called a die coater or curtain flow coater), an ink jet or the like. The coating property tends to be good, which is preferable.

In the photosensitive resin composition of the present invention, if necessary, a filler, other polymer compound, a surfactant, an adhesion promoter, an antioxidant, an ultraviolet absorber, an anti-aggregation material, an aggregating agent, a chain transfer An additive (E) such as an agent can also be used in combination.
Examples of the filler include glass, silica, and alumina.
Examples of other polymer compounds include curable resins such as epoxy resins and maleimide resins, and thermoplastic resins such as polyvinyl alcohol, polyacrylic acid, polyethylene glycol monoalkyl ether, polyfluoroalkyl acrylate, polyester, and polyurethane. .
As the surfactant, commercially available surfactants can be used, and examples thereof include silicone-based, fluorine-based, ester-based, cationic-based, anionic-based, nonionic-based, and amphoteric surfactants. Or a combination of two or more. Examples of the surfactant include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyethylene glycol diesters, sorbitan fatty acid esters, fatty acid-modified polyesters, tertiary amine-modified polyurethanes, and polyethyleneimines. In addition, KP (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow (manufactured by Kyoei Chemical Co., Ltd.), F-Top (manufactured by Tochem Products), MegaFuck (manufactured by Dainippon Ink & Chemicals, Inc.) ), FLORARD (manufactured by Sumitomo 3M Co., Ltd.), Asahi Guard, Surflon (manufactured by Asahi Glass Co., Ltd.), Solsperse (manufactured by Geneca Co., Ltd.), EFKA (manufactured by EFKA CHEMICALS), PB82
1 (manufactured by Ajinomoto Co., Inc.).
Specific examples of the adhesion promoter include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2- Aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) Examples include ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, and 3-mercaptopropyltrimethoxysilane.
Specific examples of the antioxidant include 2,2′-thiobis (4-methyl-6-tert-butylphenol) and 2,6-di-tert-butyl-4-methylphenol.
Specific examples of the ultraviolet absorber include 2- (3-tert-butyl-2-hydroxy-5-methylphenyl) -5-chlorobenzotriazole and alkoxybenzophenone.
Specific examples of the flocculant include sodium polyacrylate.
Examples of the chain transfer agent include dodecyl mercaptan and 2,4-diphenyl-4-methyl-1-pentene.

  Since the photosensitive resin composition of the present invention does not contain a resin component as described in Patent Document 1, the rate of change in viscosity after storage with respect to the viscosity before storage is small, which is preferable.

  The photosensitive resin composition of this invention can be easily adjusted by methods, such as mixing each component of said (A)-(D) and (E) component in arbitrary orders as needed.

The photosensitive resin composition is, for example, on a substrate (for example, a color filter or a liquid crystal driving circuit formed on a substrate) or a substrate (for example, glass, plastic, silicon, etc.) as follows. The pattern can be formed by coating on top, photocuring and developing. First, this composition is apply | coated on the layer which consists of solid content of the photosensitive resin composition formed previously in the board | substrate. The coating is performed using a known apparatus such as a spin coater, a slit coater, a curtain flow coater, or a bar coater.
The applied photosensitive resin composition layer is pre-baked to remove volatile components such as a solvent to obtain a smooth coating film. The thickness of the coating film at this time is usually about 1 to 6 μm.
The coating film thus obtained is irradiated with ultraviolet rays through a mask for forming a target pattern. At this time, it is preferable to use an apparatus such as a mask aligner or a stepper so that the entire exposed portion is uniformly irradiated with parallel light rays and the mask and the substrate are accurately aligned. Thereafter, the cured coating film is brought into contact with an alkaline aqueous solution to dissolve the unexposed portion and developed, whereby the intended pattern shape is obtained. The developing method may be any of a liquid piling method, a dipping method, a spray method, and the like. Further, the substrate may be tilted at an arbitrary angle during development. After the development, it is washed with water, and further post-baked at 150 to 230 ° C. for 10 to 60 minutes, if necessary.

The developer used for development after patterning exposure is usually an aqueous solution containing an alkaline compound and a surfactant.
The alkaline compound may be either an inorganic or organic alkaline compound. Specific examples of the inorganic alkaline compound include sodium hydroxide, potassium hydroxide, disodium hydrogen phosphate, sodium dihydrogen phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, potassium dihydrogen phosphate, sodium silicate, potassium silicate, Examples thereof include sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, sodium borate, potassium borate, and ammonia.
Specific examples of the organic alkaline compound include tetramethylammonium hydroxide, 2-hydroxyethyltrimethylammonium hydroxide, monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, and ethanolamine. Etc. These inorganic and organic alkaline compounds can be used alone or in combination of two or more. The concentration of the alkaline compound in the alkaline developer is preferably 0.01 to 10% by mass, more preferably 0.03 to 5% by mass.

The surfactant in the alkaline developer may be any of a nonionic surfactant, an anionic surfactant, or a cationic surfactant.
Specific examples of nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene aryl ether, polyoxyethylene alkyl aryl ether, other polyoxyethylene derivatives, oxyethylene / oxypropylene block copolymers, sorbitan fatty acid esters, polyoxyethylene Examples thereof include oxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, glycerin fatty acid ester, polyoxyethylene fatty acid ester, and polyoxyethylene alkylamine.
Specific examples of anionic surfactants include higher alcohol sulfate salts such as sodium lauryl alcohol sulfate and sodium oleyl alcohol sulfate, alkyl sulfates such as sodium lauryl sulfate and ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, And alkyl aryl sulfonates such as sodium dodecyl naphthalene sulfonate.
Specific examples of the cationic surfactant include amine salts or quaternary ammonium salts such as stearylamine hydrochloride and lauryltrimethylammonium chloride.
These surfactants can be used alone or in combination of two or more.
The concentration of the surfactant in the alkali developer is usually 0.01 to 10% by mass, preferably 0.05 to 8% by mass, and more preferably 0.1 to 5% by mass.

The cured resin pattern can be formed on the substrate or the color filter substrate through the operations such as application of the photosensitive resin liquid, drying, patterning exposure to the resulting dried coating film, and development.
Moreover, this cured resin pattern is useful as a photospacer used in a liquid crystal display device. Further, among liquid crystal display devices, an MVA (Multi-domain Vertical Alignment) liquid crystal display device having an improved viewing angle has a structure in which protrusions are formed locally by providing a structure on the base of an alignment film. Even so, the pattern formed using the photosensitive resin composition of the present invention is useful. Moreover, if a photomask for hole formation is used in patterning exposure to a dry coating film, a hole can be formed and it is useful as an interlayer insulation film. Furthermore, when the dry coating film is exposed, a resin film can be formed by exposure and heat curing or only heat curing without using a photomask, and this resin film is useful as an overcoat.

  And the color filter manufactured using the photosensitive resin composition of this invention has a small in-plane film thickness difference, for example, is a film thickness of 1-6 micrometers, and an in-plane film thickness difference is 0.15 micrometer or less, Furthermore, Can be 0.05 μm or less. Therefore, the color filter obtained in this way is excellent in smoothness, and is excellent by incorporating the color filter into a color liquid crystal display device as described in, for example, JP-A-11-264969. A quality liquid crystal display device can be manufactured with a high yield.

  Although the embodiments of the present invention have been described above, the embodiments of the present invention disclosed above are merely examples, and the scope of the present invention is not limited to these embodiments. The scope of the present invention is defined by the terms of the claims, and includes the meaning equivalent to the description of the claims and all modifications within the scope. EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by these Examples.

  The structure and the like of the binder resin used in Example 1, Example 2, and Comparative Example 1 are shown in Formula (X), Formula (Y), and Table 1. In Table 1, a to h indicate molar ratios.

  Since no isocyanate compound was used in the binder resin, there was no peculiar odor caused by the isocyanate compound.

Explanation of Structural Units a: Structural units derived from (A1) in the copolymer 1.
b: A structural unit derived from (A2) in the copolymer 1.
c: A structural unit derived by reacting (A3) with the structural unit derived from (A4) in the copolymer 1.
d: A structural unit derived by reacting (A5) with a site derived from (A3) in copolymer 2.
e: A structural unit derived from (A1) of the copolymer obtained by reacting (A1), (A2) and (A3).
f: A structural unit derived from (A2) of the copolymer obtained by reacting (A1), (A2) and (A3).
g: A structural unit derived from (A3) of the copolymer obtained by reacting (A1), (A2) and (A3).
h: a structural unit obtained by reacting the structural unit derived from (A4) with the structural unit derived from (A3) of the copolymer obtained by reacting (A1), (A2) and (A3).

About the measurement of polystyrene conversion weight average molecular weight (Mw) and number average molecular weight (Mn) of said binder polymer, it carried out on condition of the following using GPC method.
Equipment: HLC-8120GPC (manufactured by Tosoh Corporation)
Column; TSK-GELG4000HXL + TSK-GELG2000HXL (series connection)
Column temperature: 40 ° C
Solvent; THF
Flow rate: 1.0 ml / min
Injection volume: 50 μl
Detector; RI
Measurement sample concentration: 0.6 mass% (solvent: THF)
Standard material for calibration; TSK STANDARD POLYSTYRENE F-40, F-4, F-1, A-2500, A-500 (manufactured by Tosoh Corporation)
The ratio of the weight average molecular weight and the number average molecular weight obtained above was defined as molecular weight distribution (Mw / Mn).

  Table 2 shows the compositions of the examples and comparative examples. Numerical values in Table 2 represent parts by mass.

A 2-inch square glass substrate (manufactured by Corning, # 1737) was sequentially washed with a neutral detergent, water and alcohol and then dried. On this glass substrate, the photosensitive resin composition (Table 2) is exposed at an exposure amount (365 nm) of 100 mJ / cm ² and spinned so that the film thickness after development, water washing and post-baking becomes 4.7 μm. Coated and then prebaked at 100 ° C. for 3 minutes in a clean oven. After cooling, the space between the substrate coated with the photosensitive resin composition and a quartz glass photomask (a square with a side of 20 μm and a space portion having a pattern with a ratio of 1: 2) is set to 50 μm, and ultra-high pressure mercury Using a lamp (USH-250D; manufactured by Ushio Electric Co., Ltd.), light was irradiated with an exposure amount (365 nm) of 100 mJ / cm ^{2 in} an air atmosphere. Thereafter, in the developer in which the coating film is stirred at 23 ° C. (300 rpm with a magnetic stirrer) in an aqueous developer containing 0.12% by mass of a nonionic surfactant and 0.05% by mass of potassium hydroxide. It was developed by dipping for 80 seconds, washed with water, and post-baked at 220 ° C. for 30 minutes to obtain a cured resin pattern.

  Table 3 shows the results of measurement and the like in the following items of the obtained cured resin pattern.

(Explanation in Table 3)
NMP resistance: In the exposure step, a coating film was prepared by performing the same operation as described in Examples except that no photomask was used. The prepared coating film was immersed in N-methylpyrrolidone (30 ° C. × 30 minutes), and the change in film thickness before and after immersion was measured. Change in film thickness before and after immersion (= (film thickness after immersion (μm) / film thickness before immersion (μm)) × 100) is 103% or less, and ○ is over 103%. .
Surface smoothness: The standard of the surface smoothness indicates that the surface is visually observed, ◯ if it is glossy, and x if it is cloudy (opaque).
Particulate foreign matter: The surface is visually observed.
Line width: The dimension of two sides in the bottom part of the pattern was measured using SEM (model number S-4100; manufactured by Hitachi, Ltd.), and the average value of the obtained two sides was determined.
Shape: A cross section with respect to a cross section perpendicular to the substrate of the pattern was observed using the same SEM as described above.
Recovery rate: using a dynamic ultra-micro hardness meter (DUH-W201S; manufactured by Shimadzu Corporation), the total displacement (μm) and the elastic displacement (μm) were measured under the following conditions, and obtained. The recovery rate was calculated from the numerical values.

Test mode: Load-unloading test test force: 5 gf (SI unit converted value; 0.049 N)
Load speed: 0.45 gf / sec (SI unit conversion value: 0.0044 N / sec)
Holding time: 5-second indenter; truncated cone indenter (diameter 50 mmφ)
Recovery rate (%) = (elastic displacement (μm) / total displacement (μm)) × 100

Storage stability: Viscosity change rate before and after storage for 3 months at 23 ° C. was determined by the following formula.
Viscosity change rate (%) = [(viscosity after storage) / (viscosity before storage)] × 100

  In the photosensitive resin compositions of Examples 1 and 2 containing the binder resin of the present invention, it is understood that a pattern and a coating film excellent in NMP resistance, surface smoothness, pattern shape, recovery rate and the like can be obtained. The photosensitive resin composition of Comparative Example 1 that does not contain the binder resin is inferior in NMP resistance.

  The photosensitive resin composition of this invention can be used for formation of the photo spacer in a liquid crystal display device.

Claims (10)

In the photosensitive resin composition containing the binder resin (A), the photopolymerizable compound (B), the photopolymerization initiator (C) and the solvent (D),
The binder resin (A) is obtained by copolymerizing the following (A1), (A2) and (A4) to obtain a copolymer 1, and the obtained copolymer 1 and (A3) are combined into the copolymer 1. The copolymer 2 is obtained by reacting at the site of the epoxy group derived from (A4), and the obtained copolymer 2 and (A5) are further reacted with (A4) and (A3) of the copolymer 1 The photopolymerization initiator (C) is a copolymer obtained by reacting with a hydroxyl group produced by the above, at least selected from the group consisting of acetophenone compounds, biimidazole compounds, oxime compounds and triazine compounds. A kind of compound,
A photosensitive resin composition used for forming a photospacer.
(A1); Compound (A2) having at least one skeleton selected from the group consisting of a tricyclodecane skeleton and a dicyclopentadiene skeleton and an unsaturated bond in one molecule; and (A1) and (A4) Compound (A3) having polymerizable unsaturated bond; Carboxylic acid (A4) having unsaturated bond; Compound (A5) having unsaturated bond and epoxy group in one molecule; Acid anhydride provided that (A1) -(A5) are not mutually the same.   (A1) is at least selected from the group consisting of dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, and dicyclopentenyloxyethyl (meth) acrylate The photosensitive resin composition according to claim 1, which is a single compound.   The photosensitive resin composition according to claim 1 or 2, wherein (A2) is at least one compound selected from the group consisting of styrene, benzyl (meth) acrylate, and N-substituted maleimide.   The photosensitive resin composition according to claim 1, wherein (A3) is at least one compound selected from the group consisting of acrylic acid and methacrylic acid.   5. The photosensitive resin composition according to claim 1, wherein (A4) is at least one compound selected from the group consisting of glycidyl acrylate and glycidyl methacrylate.   (A5) is maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, methyltetrahydrophthal The photosensitive resin composition according to claim 1, which is at least one compound selected from the group consisting of an acid anhydride and trimellitic anhydride.   The ratio of the structural unit produced by the reaction of (A4) and (A3) is a binder resin (A) that is 30 to 60 mol% with respect to all structural units. Photosensitive resin composition.   The photospacer formed using the photosensitive resin composition in any one of Claims 1-7.   A color filter comprising the photospacer according to claim 8.   A liquid crystal display device comprising the color filter according to claim 9.