WO2019059169A1 - Transparent photosensitive resin composition, photospacer, liquid crystal display device, method for producing photospacer, method for producing liquid crystal display device, and use of transparent photosensitive resin composition for lens scan exposure - Google Patents

Abstract

The purpose of the present invention is to provide: a transparent photosensitive resin composition that enables the formation of photospacers which are suppressed in height variation, while being not susceptible to plastic deformation, in other words, having high elastic recovery rate at the same time; a photospacer which is obtained using this transparent photosensitive resin composition; a liquid crystal display device; a method for producing a photospacer; a method for producing a liquid crystal display device; and use of this transparent photosensitive resin composition for lens scan exposure. The present invention is a transparent photosensitive resin composition which contains at least an alkali-soluble resin, a photopolymerization initiator and a polymerizable monomer, and wherein: the alkali-soluble resin has (A) a structural unit represented by general formula (1), (B) a structural unit represented by general formula (2), and (C) a structural unit represented by general formula (3); and the ethylenically unsaturated group equivalent of the alkali-soluble resin is 400 g/mol or less. (In general formula (1), R1 represents a hydrogen atom or a methyl group.) (In general formula (2), each of R2 and R3 independently represents a hydrogen atom or a methyl group; and X represents -CH2CH(OH)CH2O(C=O)-, -CH2CH2NH(C=O)O(CH2)mO(C=O)- or -(CH2)nO(C=O)NHCH2CH2O(C=O)-, wherein each of m and n independently represents an integer of 1-4.) (In general formula (3), Y represents an optionally substituted aryl group having 6-11 carbon atoms, an optionally substituted aralkyl group having 7-10 carbon atoms or an optionally substituted cycloalkyl group having 3-10 carbon atoms.)

Description

Transparent photosensitive resin composition, photo spacer, liquid crystal display device, method of manufacturing photo spacer, method of manufacturing liquid crystal display device, and use of transparent photosensitive resin composition for lens scan exposure

The present invention relates to a transparent photosensitive resin composition, a photospacer, a liquid crystal display, a method of manufacturing a photospacer, a method of manufacturing a liquid crystal display, and use of the transparent photosensitive resin composition for lens scan exposure.

Liquid crystal display devices are used in various applications such as laptop computers, personal digital assistants, smart phones, digital cameras and desktop monitors, taking advantage of characteristics such as light weight, thinness and low power consumption.

The liquid crystal display device includes a liquid crystal layer capable of displaying an image according to a predetermined orientation between a color filter substrate and a TFT (Thin Film Transistor) substrate, and the distance (cell gap) between these substrates is made uniform. Maintaining is one of the important factors affecting image quality.

Conventionally, in order to keep the cell gap uniform, spacer particles such as glass or alumina having a predetermined particle diameter have been used. Since these spacer particles are randomly scattered on the substrate, there is a problem such as display unevenness due to film thickness variation.

To solve this problem, a photosensitive film for resin spacer formation, which is used to form a resin spacer for liquid crystal display comprising a support film and a photosensitive resin layer having a thickness of 1 to 10 μm, has been proposed (for example, , Patent Document 1). However, even if the resin spacer described in Patent Document 1 is used, plastic deformation occurs at the time of assembling (cell pressure bonding) between the color filter and the TFT array substrate, and thus the display unevenness is apt to occur due to spacer height variations. there were.

As a technique for suppressing the plastic deformation of the spacer, a plurality of columnar spacers are provided in the non-display area on the substrate so far, and the columnar spacer has an elastic deformation ratio to a compressive load of 2.0 GPa at room temperature. A photosensitive resin composition for a spacer comprising, as a main component, a liquid crystal panel substrate (see, for example, Patent Document 2), an alkali-soluble resin, a photopolymerization initiator, and a polymerizable monomer, which is 60% or more. A photosensitive resin composition for spacers (see, for example, Patent Document 3) or the like, which is characterized in that the acrylic equivalent of the whole of these photosensitive resin compositions is 200 or less has been proposed.

On the other hand, in order to increase the number of chamfers and improve the yield, the mother glass substrate is increasing in size, and a constant speed is provided by the substrate transfer means as a technique for exposing a substrate having a wide exposure area using a small mask. The exposure light from the continuous light source is irradiated through the opening of the mask provided on the light path of the exposure optical system in the exposure unit to the substrate being transported in a predetermined direction. A scan exposure method for transferring an image has been proposed (see, for example, Patent Document 4).

Japanese Patent Application Laid-Open No. 11-174464 Unexamined-Japanese-Patent No. 2003-241199 JP, 2005-292269, A Unexamined-Japanese-Patent No. 2006-292955

Methods of increasing the elastic deformation rate of the columnar spacers described in Patent Documents 2 and 3 include a method in which a large amount of a monomer having a large number of functional groups is contained in the photosensitive resin composition. The coating film of the base resin composition has high fluidity even after drying, and unevenness in film thickness easily occurs in the production process, so that the height of the photospacer tends to vary.

On the other hand, in the scan exposure method of Patent Document 4, particularly in the case of lens scan type exposure in which a plurality of lenses are arranged in two rows, twice at the joint portion between the lens and the lens where the exposure amount is lower than that of the normal portion. It is designed to have the same exposure amount as that of a normal part in exposure, and a wide range of printing is possible.

However, when a photosensitive resin composition containing a large amount of monomers as described in Patent Documents 2 and 3 is exposed by a lens scan method, the height of the photo spacer formed at the joint portion between the lens and the lens There was a problem that the variation became large. Since variations in the height of the photo spacers cause the display unevenness of the liquid crystal display device, it is required to form the photo spacers at a uniform height.

Further, in the case of proximity type exposure, which is a conventional exposure type, when the distance between the photo spacers is about 15 μm or less, the photo spacers tend to be connected due to the influence of diffracted light. In order to avoid such connection, multipatterning in which one plate is shifted to perform multiple exposure has been proposed. However, even in multi-patterning, the film thickness of the next exposed portion becomes thinner due to the flow of the pre-baking film after the first exposure, and there is a problem that the dispersion of the height of the photo spacer becomes large.

Therefore, the present invention is directed to a transparent photosensitive resin composition which can suppress the variation of the height of the photospacer and can form a photospacer which is resistant to plastic deformation, that is, having a high elastic recovery ratio. It is an object of the present invention to provide a photo spacer, a liquid crystal display device, a method of manufacturing the photo spacer, a method of manufacturing the liquid crystal display device, and use of the transparent photosensitive resin composition for lens scan exposure.

In order to solve the above-mentioned subject, the present invention mainly has the following composition.
A transparent photosensitive resin composition comprising at least an alkali soluble resin, a photopolymerization initiator and a polymerizable monomer, wherein the alkali soluble resin is A) a structural unit represented by the following general formula (1):
B) Structural units represented by the following general formula (2):
C) having a structural unit represented by the following general formula (3),
The transparent photosensitive resin composition whose ethylenically unsaturated group equivalent of the said alkali-soluble resin is 400 g / mol or less.

In the above general formula (1), R ¹ represents a hydrogen atom or a methyl group.

In the above general formula (2), R ² and R ³ each independently represent a hydrogen atom or a methyl group. X is _{-CH 2 CH (OH) CH 2} O (C = O) -, - CH 2 CH 2 NH (C = O) O (CH 2) m O (C = O) - or - _{(CH 2) n O (C = O) NHCH 2} CH 2 O (C = O) - shows the. However, m and n each independently represent an integer of 1 to 4.

In the above general formula (3), Y has an aryl group having 6 to 11 carbon atoms which may have a substituent, an aralkyl group having 7 to 10 carbon atoms which may have a substituent, or a substituent. And an optionally substituted C 3-10 cycloalkyl group.

According to the transparent photosensitive resin composition of the present invention, even when exposure is performed by a lens scan method or a proximity method in which the variation in height of the photo spacer tends to be large, the high elastic recovery rate suppressed the variation in height. Can be formed.

It is the schematic which shows an example of the hysteresis curve showing the elastic characteristic of a photo spacer.

The transparent photosensitive resin composition of the present invention (hereinafter sometimes referred to as "photosensitive resin composition") contains at least an alkali-soluble resin, a photopolymerization initiator and a polymerizable monomer. By containing a photopolymerization initiator and a polymerizable monomer, the exposed portion can be photocured to be insolubilized in an alkali developer, and by containing an alkali-soluble resin, it is not exposed using an alkali developer. Since the part can be removed, the desired pattern can be formed by exposure and development.

The "transparent" in the present invention means that the light transmittance at a wavelength of 400 to 700 nm is 80% or more when the photosensitive resin composition is photocured to form a cured film having a thickness of 3 μm. The photosensitive resin composition of the present invention is preferably substantially free of a colorant such as a pigment or a dye in order to increase the light transmittance at a wavelength of 400 to 700 nm.

The alkali-soluble resin in the present invention means a resin having a structural unit represented by the general formula (1) described later. By having a carboxyl group, the solubility in an alkali developer can be enhanced.

The alkali-soluble resin in the present invention is represented by A) a structural unit represented by the following general formula (1), B) a structural unit represented by the following general formula (2), and C) the following general formula (3) Have structural units. By having a structural unit represented by the following general formula (1), the solubility of the resin in an alkali developer can be improved. By introducing an ethylenically unsaturated group into the side chain of the alkali-soluble resin by having a structural unit represented by the following general formula (2), the sensitivity in exposure and development and the elastic recovery of the photospacer are improved. Can. By having a structural unit represented by the following general formula (3), variation in height of the photo spacer can be suppressed.

In the above general formula (1), R ¹ represents a hydrogen atom or a methyl group. R ¹ is preferably a methyl group, which can increase the viscosity of the pre-baked film and can further suppress variations in height.

In the above general formula (2), R ² and R ³ each independently represent a hydrogen atom or a methyl group. X is _{-CH 2 CH (OH) CH 2} O (C = O) -, - CH 2 CH 2 NH (C = O) O (CH 2) m O (C = O) - or - _{(CH 2) n O (C = O) NHCH 2} CH 2 O (C = O) - shows the. However, m and n each independently represent an integer of 1 to 4.

In the above general formula (3), Y has an aryl group having 6 to 11 carbon atoms which may have a substituent, an aralkyl group having 7 to 10 carbon atoms which may have a substituent, or a substituent. And an optionally substituted C 3-10 cycloalkyl group. Y is preferably a cycloalkyl group having a carbon number of 3 to 10 which may have a substituent, more preferably a cyclohexyl group, which can further increase the viscosity of the pre-baked film and can further suppress the variation in height.

The alkali-soluble resin in the present invention is, for example, a copolymer component constituting the structural unit represented by the general formula (1), a copolymer component constituting the structural unit represented by the general formula (2), and the general It can obtain by copolymerizing the copolymerization component which comprises the structural unit represented by Formula (3). Furthermore, other copolymerizable components may be copolymerized.

An ethylenically unsaturated compound having a glycidyl group is subjected to an addition reaction with the carboxyl group of the acrylic polymer having the structural unit represented by the general formula (1) and the structural unit represented by the general formula (3) Thus, the structural unit represented by the general formula (2) can be introduced. Similarly, it has a carboxyl group to the glycidyl group, the hydroxyl group, and the isocyanate group of the acrylic polymer having the structural unit represented by the general formula (1) and the structural unit represented by the general formula (3) The structural unit represented by the general formula (2) can be introduced also by the addition reaction of an ethylenically unsaturated compound, an ethylenically unsaturated compound having an isocyanate group, and an ethylenically unsaturated compound having a hydroxyl group. it can.

As a copolymerization component which comprises the structural unit represented by the said General formula (1), (meth) acrylic acid etc. are mentioned, for example. Two or more of these may be used. Among these, methacrylic acid is preferable, and the viscosity of the pre-baked film can be further increased, and the variation in height can be further suppressed.

As a copolymerization component which comprises the structural unit represented by said General formula (2), (meth) acrylic acid; glycidyl (meth) acrylate, 2-isocyanatoethyl methacrylate, 2-hydroxyethyl (meth) acrylate, for example Etc. Two or more of these may be used. Among these, it is preferable to add glycidyl (meth) acrylate to (meth) acrylic acid.

As a copolymerization component which comprises the structural unit represented by said General formula (3), N- benzyl maleimide, N- phenyl maleimide, N- cyclohexyl maleimide etc. are mentioned, for example. Two or more of these may be used. Among these, N-cyclohexyl maleimide is preferable, and the viscosity of the pre-baked film can be further increased, and the variation in height can be further suppressed.

Other copolymerization components include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate ( (Meth) acrylic acid sec-butyl, (meth) acrylic acid isobutyl, (meth) acrylic acid tert-butyl, (meth) acrylic acid n-pentyl, 2-hydroxyethyl (meth) acrylate, benzyl (meth) acrylate, benzyl ( Unsaturated carboxylic acid alkyl ester such as meta) acrylate and isobornyl (meth) acrylate; Unsaturated carboxylic acid amino alkyl ester such as aminoethyl acrylate, Polyvalent carboxylic acid such as mono (2- (meth) acryloyloxyethyl) phthalate Acid monoester; styrene, p-methylstyrene, o Aromatic vinyl compounds such as methylstyrene, m-methylstyrene and α-methylstyrene; Vinyl esters of carboxylic acids such as vinyl acetate and vinyl propionate; Vinyl cyanide compounds such as (meth) acrylonitrile and α-chloro (meth) acrylonitrile Aliphatic conjugated dienes such as 1,3-butadiene and isoprene; dicyclopentenyl (meth) acrylate, dicyclopentenyl oxyethyl (meth) acrylate, tricyclodecanyl (meth) acrylate, tricyclodecane dimethanol di (meth); ) Ethylenic unsaturated compounds having a tricyclodecane skeleton or dicyclopentadiene skeleton such as acrylates; monocarboxylic acids such as crotonic acid and vinyl acetic acid or acid anhydrides thereof; dicarboxylic acids such as itaconic acid, maleic acid, fumaric acid or the like That Acid anhydride and the like.

When the total amount of structural units of the alkali-soluble resin is 100 mol%, the amount of the structural unit represented by the general formula (3) is preferably 10 to 23 mol%. The dry viscosity can be further increased when the amount of the structural unit represented by the general formula (3) is 10 mol% or more, and the viscosity of the pre-baked film can be further increased when the amount is 15 mol% or more. On the other hand, the ethylenic unsaturated bond equivalent and an acid value can be easily adjusted to the preferable range mentioned later as the structural unit quantity represented by the said General formula (3) is 23 mol% or less.

The ethylenically unsaturated group equivalent of the alkali-soluble resin in the present invention is 400 g / mol or less. When the ethylenically unsaturated group equivalent exceeds 400 g / mol, the crosslink density of the photo spacer decreases and the elastic recovery rate decreases. 360 g / mol or less is preferable and 300 g / mol or less of the ethylenically unsaturated group equivalent of alkali-soluble resin is more preferable.

Here, the ethylenically unsaturated group equivalent refers to the number of grams per mole of the ethylenically unsaturated group, and the smaller the value, the larger the amount of the ethylenically unsaturated group contained. For example, the higher the content ratio of the structural unit represented by the general formula (2) B having an ethylenically unsaturated group, the smaller the equivalent amount of the ethylenically unsaturated group. The ethylenically unsaturated group equivalent of the alkali-soluble resin can be adjusted to a desired range by the copolymerization ratio of the compound having the ethylenically unsaturated group. The ethylenically unsaturated group equivalent can be calculated by measuring the iodine value by the method described in paragraph 6.0 of the test method of JIS K 0070: 1992.

The weight average molecular weight ("Mw") of the alkali-soluble resin in the present invention is preferably 10,000 to 100,000. By setting Mw to 10,000 or more, the viscosity of the pre-baked film can be increased, and the variation in height can be further suppressed. Mw is more preferably 20,000 or more. On the other hand, by setting Mw to 100,000 or less, unevenness of the pattern surface can be suppressed, and the surface shape of the pattern can be improved. Mw is more preferably 80,000 or less. Here, Mw of the alkali-soluble resin in the present invention is a value converted by standard polystyrene, and can be measured using gel permeation chromatography.

The acid value of the alkali-soluble resin in the present invention is preferably 60 to 100 mg KOH / g. By setting the acid value to 60 mg KOH / g or more, the height variation can be further reduced. The acid value is more preferably 65 mg KOH / g or more. On the other hand, by setting the acid value to 100 mgKOH / g or less, unevenness on the surface of the pattern can be suppressed, and the surface shape of the pattern can be improved. The acid value is more preferably 95 mg KOH / g or less. The acid value of the alkali-soluble resin can be adjusted to a desired range by the copolymerization ratio of the compound having a carboxyl group. Here, the acid value of the alkali-soluble resin in the present invention can be determined by the neutralization titration method of test method section 3.1 of JIS K 0070: 1992. When using an alkali-soluble resin solution with a solid content concentration of about 30% by mass, 5 g of the alkali-soluble resin solution is put in an aluminum cup (φ 45 mm) and heated at 130 ° C. for 1 hour to remove the solvent. As a result, it is possible to obtain an alkali-soluble resin solid content in an amount necessary for measuring the acid value.

When the alkali-soluble resin is obtained by adding glycidyl (meth) acrylate to (meth) acrylic acid, unreacted glycidyl (meth) acrylate may remain together with the alkali-soluble resin. The residual amount of glycidyl (meth) acrylate is preferably 0.001 to 0.500% by mass per solid content in the method determined above. By setting the residual amount of glycidyl (meth) acrylate to 0.001% by mass or more, the heating time for removing glycidyl (meth) acrylate does not need to be long, and the gelation of the alkali-soluble resin due to heating is suppressed be able to. On the other hand, by setting the residual amount of glycidyl (meth) acrylate to 0.500% by mass or less, it is possible to suppress the loss during development. 0.2% or less is more preferable, and 0.03% or less is even more preferable. Here, the remaining amount of glycidyl (meth) acrylate of the alkali-soluble resin can be determined from the amount of glycidyl (meth) acrylate measured from the alkali-soluble resin solution using gas chromatography and the solid content concentration of the alkali resin solution .

The content of the alkali-soluble resin in the photosensitive resin composition of the present invention is preferably 25 to 82 parts by mass with respect to 100 parts by mass of a polymerizable monomer described later. By setting the content of the alkali-soluble resin to 25 parts by mass or more, the height variation can be further suppressed. The content of the alkali-soluble resin is more preferably 34 parts by mass or more. On the other hand, by setting the content of the alkali-soluble resin to 82 parts by mass or less, the elastic recovery rate can be further improved. 66 mass parts or less are more preferable, 62 mass parts or less are more preferable, 55 mass parts or less are more preferable, and 40 mass parts or less are more preferable as content of alkali-soluble resin.

The photopolymerization initiator in the present invention refers to a compound which is decomposed and / or reacted by light (including ultraviolet light or electron beam) to generate a radical. The photosensitive resin composition of the present invention can improve sensitivity by containing a photopolymerization initiator. Examples of the photopolymerization initiator include oxime ester compounds, alkylphenone compounds, benzophenone compounds, thioxanthone compounds, imidazole compounds, benzothiazole compounds, benzoxazole compounds, acylphosphine oxide compounds, and titanocene compounds. A compound etc. are mentioned. Two or more of these may be contained.

Examples of oxime ester compounds include 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], ethanone, 1- [9-ethyl-6- (2-) Methyl benzoyl) -9H-carbazol-3-yl]-, 1- (O-acetyloxime), ethanone, 1- [9-ethyl-6- (2-methyl-4-tetrahydrofuranylmethoxybenzoyl) -9H-carbazole -3-yl]-, 1- (O-acetyloxime), ethanone, 1- [9-ethyl-6- {2-methyl-4- (2,2-dimethyl-1,3-dioxolanyl) methoxybenzoyl} -9H-Carbazol-3-yl]-, 1- (O-acetyloxime), “Optomer” (registered trademark) N-1919, NCI-831, NCI-930 (or more) Both Co., Ltd. ADEKA), "IRGACURE" (registered trademark) OXE01, OXE02, OXE03 (or more, both BASF Japan Co., Ltd.), and the like.

Examples of the alkylphenone compounds include 2,2-diethoxyacetophenone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone, 2- (dimethylamino) -2-[(4) -Methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, α-hydroxyisobutylphenone, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1- Examples thereof include phenyl-propan-1-one, “IRGACURE” (registered trademark) 907 (manufactured by BASF Japan Ltd.), and the like.

Examples of benzophenone compounds include benzophenone, N, N'-tetraethyl-4,4'-diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone and the like.

Examples of thioxanthone compounds include thioxanthone, 2-chlorothioxanthone, 2-methyl thioxanthone, 2-isopropyl thioxanthone, 4-isopropyl thioxanthone, 2,4-dimethyl thioxanthone, 2,4-diethyl thioxanthone, 2,4-diiso. Pirthioxanthone, 1-chloro-4-propylthioxanthone, 1-hydroxycyclohexyl phenyl ketone and the like can be mentioned.

Examples of the imidazole compounds include 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer and the like.

Examples of the benzothiazole compound include 2-mercaptobenzothiazole and the like.

Examples of the benzoxazole compounds include 2-mercaptobenzoxazole and the like.

Examples of the acyl phosphine oxide compound include 2,4,6-trimethyl benzoyl-diphenyl-phosphine oxide, bis (2,4,6-trimethyl benzoyl) -phenyl phosphine oxide and the like.

Examples of the titanocene compounds include bis (η5-2, 4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium and the like. Be

Among these, from the viewpoint of further improving sensitivity, oxime ester compounds and alkylphenone compounds are preferable. Among the oxime ester compounds, “Adekaqules” (registered trademark) N-1919 is more preferable, and among the alkylphenone compounds, “IRGACURE” (registered trademark) 907 is more preferable.

The content of the photopolymerization initiator in the photosensitive resin composition of the present invention is preferably 2 to 30 parts by mass, more preferably 5 to 25 parts by mass with respect to 100 parts by mass of the total content of the alkali-soluble resin and the polymerizable monomer. preferable.

The polymerizable monomer in the present invention refers to a monomer having at least one ethylenically unsaturated bond. Examples of the polymerizable monomer include monofunctional or polyfunctional monomers and oligomers. Two or more of these may be contained. In addition, since the crosslink density is increased and the elastic recovery rate is improved, polyfunctional monomers are preferable.

As a polyfunctional polymerizable monomer, for example, tripropylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, trimethylolpropane tri (meth) Acrylate, pentaerythritol tri (meth) acrylate, triacryl formal, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, tripentaerythritol octa (meth) acrylate, tri Pentaerythritol octa (meth) acrylate, 9,9-bis [4- (3-acryloxy-2-hydroxypropoxy) phenyl] fluorene, 9,9-bis 3-Methyl-4- (3-acryloxy-2-hydroxypropoxy) phenyl] fluorene, 9,9-bis [3-chloro-4- (3-acryloxy-2-hydroxypropoxy) phenyl] fluorene, bisphenoxyethanolfluorene Acrylate, bisphenoxyethanolfluorene methacrylate, a reaction product of dipentaerythritol pentaacrylate and succinic anhydride, and the like. Two or more of these may be contained.

Among these, from the viewpoint of facilitating adjustment of the viscosity, exposure sensitivity and processability of the pre-baked film into desired ranges, combinations of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate, and reactions of these with succinic anhydride Are preferred.

The photosensitive resin composition of the present invention comprises a filler, a sensitizer, a UV absorber, an adhesion improver, a surfactant, a polymerization inhibitor, a polymer compound other than the above-mentioned alkali-soluble compound, an organic acid, an organic amino compound, You may contain additives and solvents, such as a hardening agent.

By containing the filler, the photosensitive resin composition of the present invention can further increase the viscosity after drying of the pre-baked film, and can further suppress the height variation. Examples of the filler include inorganic oxide particles such as silica, alumina, titania and barium sulfate; metal particles; and resin particles such as acrylic, styrene, silicone and fluorine-containing polymer. Two or more of these may be contained. Among these, silica particles are preferable from the viewpoint of particle diameter and dispersibility. The average particle diameter in terms of specific surface area of the filler is preferably 4 to 120 nm. When the average particle diameter of the filler is 4 nm or more, the height variation can be further suppressed. On the other hand, when the particle diameter is 120 nm or less, unevenness of the pattern surface can be suppressed, and the surface shape of the pattern can be improved.

The photosensitive resin composition of the present invention can improve sensitivity by containing a sensitization auxiliary. Examples of the sensitization assistant include aromatic or aliphatic tertiary amines and the like.

The photosensitive resin composition of the present invention can easily form a fine, short, tapered photospacer by containing an ultraviolet light absorber. As the UV absorber, organic compound UV absorbers such as benzotriazole compounds, benzophenone compounds, and triazine compounds are preferable from the viewpoint of transparency and non-coloring property. Two or more of these may be contained. Among these, benzotriazole compounds are preferable.

Examples of benzotriazole compounds include 2- (2H-benzotriazol-2-yl) -p-cresol and 2- (2H-benzotriazol-2-yl) -4--6-bis (1-methyl-1). -Phenylethyl) phenol, 2- [5 chloro (2H) -benzotriazol-2-yl] -4-methyl-6- (tert-butylphenol), 2,4-di-tert-butyl-6- (5-chloro) Benzotriazol-2-yl) phenol, 2- (2H-benzotriazol-2-yl) phenol, 2- (2H-benzotriazol-2-yl) -4,6-tert-pentylphenol, 2- (2H- Benzotriazol-2-yl-4- (1,1,3,3-tetramethylbutyl) phenol, 2 (2H-benzotriazol-2-yl) ) -6-dodecyl-4-methylphenol, 2 [2-hydroxy-3- (3,4,5,6 tetrahydrophthalimide - methyl) -5-methylphenyl] benzotriazole and the like.

Examples of benzophenone compounds include octabenzone, 2-hydroxy-4-n-octoxybenzophenone and the like.

Examples of triazine compounds include 2- (4,6-diphenyl-1,3,5 triazin-2-yl) -5-[(hexyl) oxy] -phenol.

The content of the ultraviolet light absorber in the photosensitive resin composition of the present invention is preferably 0.3 to 10% by mass in the solid content. By setting the content of the ultraviolet absorber to 0.3% by mass or more, the tapered portion can be further shortened. As for content of a ultraviolet absorber, 2 mass% or more is more preferable. On the other hand, the sensitivity can be maintained high by setting the content of the ultraviolet absorber to 10% by mass or less. As for content of a ultraviolet absorber, 8 mass% or less is more preferable. In addition, solid content means the component except the solvent contained in the photosensitive resin composition.

As the adhesion improver, for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-amino) Ethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl Trimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane Silane coupling agents such as 3-mercaptopropyl trimethoxysilane. Two or more of these may be contained.

The content of the adhesion improver in the photosensitive resin composition of the present invention is preferably 0.1 to 20% by mass in the solid content. By making the content of the adhesion improver 0.1% by mass or more, the development adhesion can be improved. The content of the adhesion improver is more preferably 0.5% by mass or more. On the other hand, aggregation of the alkali-soluble resin and the polymerizable monomer can be suppressed by setting the content of the adhesion improver to 20% by mass or less. The content of the adhesion improver is more preferably 10% by mass or less.

As the surfactant, for example, anionic surfactants such as ammonium lauryl sulfate, polyoxyethylene alkyl ether triethanolamine and the like; cationic surfactants such as stearyl amine acetate, lauryl trimethyl ammonium chloride and the like; lauryl dimethyl amine oxide, lauryl Amphoteric surfactants such as carboxymethyl hydroxyethyl imidazolium betaine; nonionic surfactants such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, sorbitan monostearate; perfluorobutyl sulfonate, perfluoroalkyl group-containing Carboxylic acid salt, perfluoroalkyl group-containing trimethyl ammonium salt, perfluoroalkyl group-containing phosphoric acid ester, or perfluoroalkyl ether Fluorine-based surfactants such as lenoxide adducts; polyether-modified polymethylalkylsiloxane, polyether-modified polydimethylsiloxane, polyester-modified polydimethylsiloxane, polyester-modified methylalkylpolysiloxane, aralkyl-modified polymethylalkylsiloxane, polyether-modified hydroxyl group Examples thereof include silicone surfactants such as contained polydimethylsiloxane and polyester modified hydroxyl group-containing polydimethylsiloxane. Two or more of these may be contained. Among these, polyether modified polydimethylsiloxane "BYK" (registered trademark) 333 (manufactured by Bick Chemie) is preferable.

The content of the surfactant in the photosensitive resin composition of the present invention is preferably 0.001 to 10% by mass in the solid content. The coatability of the photosensitive resin composition can be improved by setting the content of the surfactant to 0.001% by mass or more. The content of the surfactant is more preferably 0.01% by mass or more. On the other hand, by setting the content of the surfactant to 10% by mass or less, unevenness of the pattern surface can be suppressed, and the surface shape of the pattern can be improved. As for content of surfactant, 1 mass% or less is more preferable.

Examples of the polymerization inhibitor include hydroquinone, tert-butyl hydroquinone, 2,5-bis (1,1,3,3-tetramethylbutyl) hydroquinone, 2,5-bis (1,1-dimethylbutyl) and the like. Hydroquinone hydroquinone polymerization inhibitors; catechol polymerization inhibitors such as catechol and tert-butyl catechol, and the like. Two or more of these may be contained.

The content of the polymerization inhibitor in the photosensitive resin composition of the present invention is preferably 0.01 to 0.5% by mass in the solid content. By setting the content of the polymerization inhibitor to 0.01% by mass or more, the storage stability over time of the photosensitive resin composition can be improved. On the other hand, by setting the content of the polymerization inhibitor to 0.5% by mass or less, it is possible to suppress the occurrence of erosion and stains on the film surface due to the decrease in sensitivity when immersed in a polar solvent.

Examples of the polymer compound other than the alkali-soluble resin include acrylic resins having no structural unit represented by the general formulas (1) to (3), alkyd resin, melamine resin, polyvinyl alcohol, polyester, polyether, polyamide , Polyamide imide, polyimide, polyimide precursor and the like. Two or more of these may be contained.

Examples of the solvent include ether solvents, ester solvents, alcohol solvents, ketone solvents, xylene, ethylbenzene, solvent naphtha and the like. Two or more of these may be contained.

Examples of the ether solvents include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol tertiary butyl ether, diethylene glycol methyl ethyl ether, dipropylene glycol monomethyl ether and the like. Among these, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and diethylene glycol methyl ethyl ether are preferable.

As an ester solvent, for example, benzyl acetate, ethyl benzoate, γ-butyrolactone, methyl benzoate, diethyl malonate, 2-ethylhexyl acetate, 2-butoxyethyl acetate, 3-methoxy-butyl acetate, 3-methoxy-3-methyl ester -Butyl acetate, diethyl oxalate, ethyl acetoacetate, 3-methoxy-butyl acetate, methyl acetoacetate, ethyl 3-ethoxy propionate, 2-ethyl butyl acetate, isopentyl propionate, propylene glycol monomethyl ether propio Nitrate, propylene glycol monoethyl ether acetate, pentyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, propylene glycol Coulter tertiary butyl ether, dipropylene glycol monomethyl ether acetate, ethyl acetate, butyl acetate, acetic acid isopentyl and the like. Among these, 3-methoxy-butyl acetate, propylene glycol monoethyl ether acetate, propylene glycol monomethyl ether propionate and the like are preferable.

Examples of alcohol solvents include butanol, 3-methyl-2-butanol and 3-methyl-3-methoxybutanol.

Examples of ketone solvents include cyclopentanone and cyclohexanone.

The photosensitive resin composition of the present invention is coated to a film thickness of 3 μm after curing, dried under reduced pressure for 200 seconds under conditions of 25 ° C. and 45 Pa, and then heat dried in an oven at 105 ° C. for 10 minutes at 23 ° C. It is preferable that the viscosity in the above becomes 1 × 10 ³ to 1 × 10 ⁸ Pa · s. By having such viscosity, it can be used suitably for the manufacturing method of the photo spacer mentioned later. Here, with the viscosity at 23 ° C. after drying, 90 mm ³ or more of the photosensitive resin composition after drying is collected, and a rheometer (MCR-302; manufactured by Anton Paar Co., Ltd.) and a plate of φ 15 mm are used. Measured thickness: 0.5 mm, frequency: 1 Hz, strain: 0.5%, measured from 20 ° C to 110 ° C at a heating rate of 0.083 ° C / sec at 23 ° C. Say the viscosity at

The photosensitive resin composition of the present invention forms a truncated cone-shaped photospacer having a diameter of 6 μm at the top and a diameter of 9 μm at the bottom, and a height of 3 μm at the bottom, and the elastic recovery rate when a load of 50 mN is applied. It is preferably 70% or more. The dispersion | variation in the height of the spacer at the time of cell pressure bonding is more suppressed as an elastic restoration rate is 70% or more, and the display nonuniformity by the plastic deformation of a photo spacer can be reduced more. The elastic recovery rate is more preferably 73% or more. As the elastic recovery rate approaches 100%, it is possible to further suppress the influence of the deformation of the photo spacer on the cell gap and the display unevenness due to it. The above shape is a typical shape of the photo spacer, and the above load is an example of the load that the photo spacer receives during manufacture or use. According to this method, the degree of plastic deformation of the photosensitive resin composition used to form the photospacer can be relatively evaluated.

FIG. 1 shows a schematic view of an example of a hysteresis curve that represents the elastic properties of the photo spacer. When a load is applied to the photo spacer, a hysteresis curve of the load applied to the photo spacer and the deformation amount D of the photo spacer as shown in FIG. 1 is obtained. By determining the total deformation amount Ha [μm], the plastic deformation amount Hb [μm] and the elastic deformation amount of the photospacer from the hysteresis curve, the elastic recovery rate of the photospacer (((Ha-Hb) / Ha) × 100) is obtained. It can be calculated. Here, after applying a pressure until a load of 50 mN is reached at a speed of 2.5 mN / sec using a hardness tester Fischer (Fischerscope H100; Helmut Fischer GmbH & Co) and a flat indenter with a diameter of 50 μm. , Speed of 2.5 mN / sec.

It is preferable to use the photosensitive resin composition of the present invention described above in order to make the elastic recovery rate when forming a photo spacer into the above range, and in particular, the ethylenically unsaturated group equivalent is in the above-mentioned preferred range Photosensitive resin compositions are more preferred.

The photosensitive resin composition of the present invention comprises an alkali-soluble resin, a photopolymerization initiator and a polymerizable monomer, and, if necessary, other additives such as a surfactant, a polymerization inhibitor, a solvent, a UV absorber and the like, as desired. It can be obtained by mixing in

The photosensitive resin composition of the present invention can be preferably used for exposure of a lens scan method because height variations can be suppressed, and can be more preferably used for formation of a photo spacer by lens scan exposure.

The shape of the photo spacer is preferably a frusto-conical shape for high definition of the color filter, and the diameter of the upper base is preferably 15 μm or less. The ratio of the diameter of the upper base to the diameter of the lower (upper base / lower lower) is preferably 0.3 to 2.0.

Next, the method of manufacturing the photo spacer of the present invention will be described by taking the case of forming it on a substrate as an example. The photosensitive resin composition of the present invention described above is preferably coated on a substrate and dried to obtain a pre-baked film, and the pre-baked film is preferably subjected to lens scan exposure and development to form a photospacer. Furthermore, it is preferable to heat-process and harden the coating film pattern after image development.

Examples of the substrate include transparent substrates such as glass and polymer films.

Examples of the method for applying the photosensitive resin composition include a dip method, a roll coater method, a spinner method, a die coating method, a wire bar coating method, and the like.

As a drying method, drying under reduced pressure, heating drying using an oven or a hot plate (pre-baking), etc. may be mentioned. In the case of drying under reduced pressure, the heating temperature is preferably 100 ° C. or less from the viewpoint of suppressing re-condensation of the drying solvent on the inner wall of the reduced pressure chamber. The reduced pressure drying pressure is preferably equal to or less than the vapor pressure of the solvent contained in the photosensitive resin composition, and is preferably 1 to 1000 Pa. The reduced pressure drying time is preferably 10 to 600 seconds. In the case of pre-baking, the heating temperature is generally 60 to 200 ° C., and the heating time is generally 1 to 60 minutes.

In the present invention, the viscosity at 23 ° C. of the pre-baked film is preferably 1 × 10 ³ to 1 × 10 ⁸ Pa · s. By exposing the pre-baked film having a viscosity of 1 × 10 ³ Pa · s or more at 23 ° C., the flowability of the pre-baked film is appropriately suppressed, and the process of transporting the pre-baked film, the exposure process, and the heating and drying (post-baking) process is performed. The occurrence of unevenness can be further suppressed. The viscosity at 23 ° C. is more preferably 1 × 10 ⁵ Pa · s or more. On the other hand, the developability can be improved by exposing the pre-baked film having a viscosity of 1 × 10 ⁸ Pa · s or less at 23 ° C. Here, the viscosity at 23 ° C. of the pre-baked film is determined by collecting 90 mm ³ or more of the pre-baked film and using a rheometer (MCR-302; Anton Paar Co., Ltd.) and a plate with a diameter of 15 mm. The viscosity at 23 ° C when measured while raising the temperature from 20 ° C to 110 ° C at a temperature rising rate of 0.083 ° C / sec under the condition of frequency: 1 Hz, strain: 0.5%. Although the temperature of the pre-baked film is heated to about 100 ° C. in the drying step in the process of producing the photospacer on the color filter substrate, it is general that it becomes about room temperature (about 23 ° C.) by cooling before exposure. It is. Therefore, in the present invention, attention was paid to the viscosity at 23 ° C. as the pre-baked film temperature during general exposure.

The obtained pre-baked film is preferably exposed to light through a mask to cure the exposed portion, and developed with an alkaline developer to remove the unexposed portion and to form a pattern.

Examples of the exposure method include proximity exposure, lens scan exposure, mirror projection exposure, stepper exposure and the like. In the present invention, lens scan exposure excellent in high definition pattern processing on a large substrate is preferably used. Since the photosensitive resin composition of the present invention can suppress height variations, it can be suitably used for lens scan exposure in which height variations are likely to occur. Examples of the lens scan exposure apparatus include FX-65S (manufactured by Nikon Corporation).

As the development step, development with an alkaline developer is preferred. As an alkali developing solution, an organic alkali developing solution, an inorganic alkali developing solution, etc. are mentioned. As the inorganic alkaline developer, an aqueous solution of sodium carbonate, sodium hydroxide, potassium hydroxide and the like is preferable. As the organic alkali developing solution, an aqueous tetramethyl ammonium hydroxide aqueous solution and an aqueous amine solution such as methanolamine are preferable. The content of the alkaline substance in the alkaline developer is preferably 0.02% by mass or more from the viewpoint of the development solubility of the unexposed area. On the other hand, from the viewpoint of further improving the pattern processability of the exposed portion, 2.0 mass% or less is preferable. The developer preferably contains a surfactant to enhance the uniformity of development. The developing solution temperature is preferably selected in the range of 18 to 40 ° C. because the developing speed changes depending on the temperature of the developing solution.

Examples of the development method include dip development, shower development, and paddle development. It is preferable to appropriately select the temperature and flow rate of the developer and the shower injection pressure, the water washing temperature after development, the flow rate and the shower injection pressure conditions. In order to remove the residue on the substrate, it is preferable to jet the developer or the washing water under high pressure, and the jetting pressure is preferably 0.01 MPa to 20 MPa.

Examples of the heat treatment apparatus for the coating film pattern after development include a hot air oven, a hot plate and the like. The heating temperature is preferably 180 to 300 ° C., and the heating time is preferably 5 to 90 minutes.

Next, a color filter substrate having a photo spacer of the present invention and a liquid crystal display device will be described.

The color filter substrate has the above-mentioned photo spacer and pixel of the present invention on the substrate. If necessary, it may have a black matrix, a planarizing film, a transparent electrode, an alignment film, and the like.

Examples of the color filter substrate include those exemplified as a substrate for forming a photo spacer.

As a pixel, a red pixel, a green pixel, a blue pixel etc. are mentioned, for example. The pixel may contain a colorant, a resin, a polymerizable monomer, a photopolymerization initiator, other additives, and the like, and may be formed of a cured product of a composition including one or more of them. Examples of the colorant include organic pigments, inorganic pigments, and dyes. As a resin, a polymerizable monomer, a photoinitiator, and other additives, what was illustrated as a component of the transparent photosensitive resin composition of this invention is mentioned, for example.

Examples of the shape of the pixel include a rectangle, a stripe, a square, a polygon, and a wave. The pixel width is preferably 1 μm or more from the viewpoint of increasing the area of the opening and improving the transmittance. On the other hand, from the viewpoint of displaying a more precise image, the pixel width is preferably 100 μm or less. The film thickness of the pixel is preferably about 1 to 5 μm.

It is preferable to have a black matrix (hereinafter, "BM") between adjacent pixels. The BM has an effect of improving the contrast of a display image by blocking light between pixels. The BM may be a color overlap BM formed by overlapping a part of pixels adjacent to each other, but in order to improve the display image by suppressing the level difference of the pixels and obtain high light shielding property, the resin and It is preferable to contain a light shielding material. As a resin, a polyimide resin or an acrylic resin is preferable. As a light shielding agent, titanium black, titanium nitride, titanium carbide, carbon black etc. are mentioned, for example. Further, it may contain an adhesion improver, a polymer dispersant, a polymerization initiator, an acid generator, a base generator, a surfactant and the like.

The film thickness of the BM is preferably 0.5 μm or more, and more preferably 0.8 μm or more, from the viewpoint of improving the light shielding property and the resistance value. On the other hand, the thickness of the BM is preferably 2.5 μm or less, and more preferably 2.0 μm or less, from the viewpoint of improving the flatness.

When the color filter substrate having pixels or BM has a step, it is preferable to have a planarization film. The planarizing film may be formed on the entire surface of the pixel or the BM, or may be selectively formed on a portion to be planarized. When the planarizing film is formed on the entire surface of the pixel or BM, the planarizing film is preferably made of a cured product of a thermosetting resin composition, and when the planarizing film is selectively formed, the planarizing film Is preferably made of a cured product of the photosensitive resin composition.

The planarizing film preferably contains a resin, and may further contain an adhesion improver, a polymer dispersant, a polymerization initiator, an acid generator, a base generator, a surfactant, and the like.

The thickness of the planarizing film is preferably 0.5 μm or more, and more preferably 1.0 μm or more from the viewpoint of flatness and suppression of the elution of impurities from the pixels. On the other hand, the thickness of the planarizing film is preferably 3.0 μm or less, more preferably 2.0 μm or less, from the viewpoint of improving the transparency.

The color filter substrate of the present invention can be obtained by forming the photo spacer and the pixel of the present invention, as necessary, a black matrix, a planarizing film, etc. on the substrate. Examples of the method of forming the pixel, the black matrix, and the planarizing film include a photolithography method, a printing method, and an electrodeposition method.

The liquid crystal display device of the present invention comprises the color filter substrate described above, a drive element side substrate disposed opposite to the color filter, a color filter substrate, and a liquid crystal alignment film provided on the drive element side substrate, respectively. It is preferable to have the photo spacer which keeps the cell gap between these liquid crystal aligning films uniform, and the liquid crystal with which it was filled in space. For example, when using a color filter substrate having a black matrix, it is preferable to have a photo spacer above the non-display area, ie, the black matrix. Note that the driving element side substrate may have a photo spacer, and in this case as well, it is preferable to have the photo spacer above the non-display area on the driving element side substrate. As a liquid crystal aligning film, resin films, such as a polyimide, are preferable.

Next, a method of manufacturing a liquid crystal display device using the color filter substrate described above will be described. It is preferable to have a step of manufacturing a photo spacer on the color filter substrate and / or the driving element side substrate by the above-mentioned manufacturing method. Specifically, the above-mentioned color filter substrate and the drive element side substrate are made to face each other, they are pasted together via a photo spacer, liquid crystal is injected from the injection port provided in the seal portion, and then the injection port is sealed. Finally, it is preferable to mount an IC driver or the like. When the liquid crystal display device has a liquid crystal alignment film, it is preferable to apply a polyimide liquid and heat-treat it, and then to carry out surface treatment by rubbing treatment or ultraviolet light treatment. From the viewpoint of suppressing the generation of fine dust and static electricity and orienting liquid crystal molecules uniformly in high definition, it is preferable to perform surface treatment by ultraviolet treatment.

The present invention will be described in detail by way of examples and comparative examples below, but the embodiments of the present invention are not limited thereto.

The properties of the alkali-soluble resin were evaluated by the following method.

(Weight average molecular weight)
For the alkali-soluble resins 1 to 13 obtained in Production Examples 1 to 13, gel permeation chromatography was used to determine converted values using standard polystyrene.

(Ethylenically unsaturated group equivalent)
The iodine value of the alkali-soluble resins 1 to 13 obtained in Production Examples 1 to 13 is measured by the method described in section 6.0 of JIS K 0070: 1992, and the ethylenically unsaturated group equivalent is calculated. did.

(Acid number)
5 g of the solution of the alkali-soluble resin 1 to 13 obtained in Production Examples 1 to 13 was placed in an aluminum cup (φ 45 mm) and heated at 130 ° C. for 1 hour to remove the solvent. The acid value of the obtained alkali-soluble resin was measured by the neutralization titration method of JIS K 0070: 1992, test method section 3.1.

(Remaining amount of glycidyl (meth) acrylate)
With respect to the solutions of alkali-soluble resins 1 to 13 obtained in Production Examples 1 to 13, as a gas chromatography using GCMS-GP2010 manufactured by Shimadzu Corporation, using DM-5MS as a column, He as a carrier gas, a column After holding the temperature at 80 ° C. for 4 minutes, the temperature was raised to 320 ° C. over 16 minutes, held at 320 ° C. for 5 minutes, and the amount of glycidyl (meth) acrylate was measured.

The solutions of alkali-soluble resins 1 to 13 obtained in Production Examples 1 to 13 are heated at 130 ° C. for 1 hour, the solid content concentration is calculated from the mass before and after heating, and the glycidyl (meth) acrylate amount and alkali soluble resin are obtained. The amount of residual glycidyl (meth) acrylate (the amount of residual GMA (mass%)) was calculated from the solid content concentration of the solution.

Production Example 1 (Alkali-soluble Resin 1)
72 g of methacrylic acid (MA), 40 g of N-cyclohexylmaleimide (CHMI), 30 g of methyl methacrylate (MMA), 3 g of 2,2'-azobis (2-methylbutyronitrile), 0.5 g of lauryl mercaptan And 220 g of propylene glycol monomethyl ether (PGME) were charged in a polymerization vessel and stirred at 90 ° C. for 2 hours under a nitrogen atmosphere, then the liquid temperature was raised to 100 ° C., and reaction was carried out by heating for 5 hours. Next, the inside of the polymerization vessel is replaced with air, and 97 g of glycidyl methacrylate (GMA), 1.2 g of dimethylbenzylamine and 0.2 g of p-methoxyphenol are added to the obtained reaction solution, and the reaction is carried out at 110 ° C. After stirring for 6 hours, PGME was added to obtain a solution of alkali-soluble resin 1 having a solid concentration of 29.5% by mass. Mw of the obtained alkali-soluble resin 1 was 40,000, the ethylenically unsaturated group equivalent was 350 g / mol, the acid value was 85 mg KOH / g, and the amount of remaining GMA was 0.05% by mass. In the alkali-soluble resin 1, MA constitutes the structural unit represented by the general formula (1), GMA constitutes the structural unit represented by the general formula (2), and CHMI is represented by the general formula (3) Construct a structural unit to be represented.

Production Example 2 (Alkali-Soluble Resin 2)
Solid content concentration 28.3 mass% in the same manner as in Production Example 1 except that the blending amount of MA is 69 g, the blending amount of CHMI is 25 g, the blending amount of MMA is 18 g, and the blending amount of GMA is 98 g. A solution of alkali soluble resin 2 was obtained. The Mw of the obtained alkali-soluble resin 2 was 43,000, the equivalent weight of the ethylenically unsaturated group was 300 g / mol, the acid value was 63 mg KOH / g, and the amount of residual GMA was 0.05 mass%.

Production Example 3 (Alkali Soluble Resin 3)
A solution of alkali soluble resin 3 having a solid content concentration of 28.5% by mass was obtained in the same manner as in Production Example 1 except that the blending amount of MA was changed to 32 g and the blending amount of GMA to 31 g. The Mw of the obtained alkali-soluble resin 3 was 39,000, the equivalent weight of the ethylenically unsaturated group was 600 g / mol, the acid value was 85 mg KOH / g, and the amount of residual GMA was 0.05% by mass.

Production Example 4 (Alkali Soluble Resin 4)
A solution of alkali soluble resin 4 having a solid concentration of 31.8% by mass was obtained in the same manner as in Production Example 1 except that the blending amount of lauryl mercaptan was changed to 2.2 g. The Mw of the obtained alkali-soluble resin 4 was 9,000, the equivalent weight of the ethylenically unsaturated group was 350 g / mol, the acid value was 85 mg KOH / g, and the residual GMA ratio was 0.05% by mass.

Production Example 5 (Alkali Soluble Resin 5)
A solution of alkali-soluble resin 5 having a solid content concentration of 31.0 mass% in the same manner as in Production Example 1 except that the blending amount of MA is 66 g, the blending amount of CHMI is 50 g, and the blending amount of GMA is 96 g. I got The Mw of the obtained alkali-soluble resin 5 was 38,000, the equivalent weight of the ethylenically unsaturated group was 350 g / mol, the acid value was 50 mg KOH / g, and the amount of residual GMA was 0.05% by mass.

Production Example 6 (Alkali-soluble Resin 6)
The solid content concentration is 30.4 mass% in the same manner as in Production Example 1 except that the blending amount of MA is 59 g, the blending amount of CHMI is 28 g, the blending amount of MMA is 19 g, and the blending amount of GMA is 70 g. A solution of alkali soluble resin 6 was obtained. The Mw of the obtained alkali-soluble resin 6 was 35,000, the equivalent weight of the ethylenically unsaturated group was 350 g / mol, the acid value was 110 mg KOH / g, and the amount of residual GMA was 0.05% by mass.

Production Example 7 (Alkali-soluble Resin 7)
13 g of methacrylic acid (MA), 15 g of N-cyclohexylmaleimide (CHMI), 72 g of methyl methacrylate (MMA), 3 g of 2,2'-azobis (2-methylbutyronitrile), 0.5 g of lauryl mercaptan And 220 g of propylene glycol monomethyl ether (PGME) were charged in a polymerization vessel and stirred at 90 ° C. for 2 hours under a nitrogen atmosphere, then the liquid temperature was raised to 100 ° C., and reaction was carried out by heating for 5 hours. After 0.2 g of p-methoxyphenol was added and cooled to room temperature, PGME was added to obtain a solution of alkali-soluble resin 7 having a solid concentration of 29.1% by mass. Mw of the obtained alkali-soluble resin 7 was 37,000, and the acid value was 85 mg KOH / g.

Production Example 8 (Production of Alkali-Soluble Resin 8)
Solid content as in Production Example 1 except that 70 g of MA, 12 g of MMA and 98 g of GMA were changed to 15 g of styrene (St) instead of CHMI. A solution of alkali soluble resin 8 having a concentration of 29.2% by mass was obtained. The Mw of the obtained alkali-soluble resin 8 was 35,000, the equivalent weight of the ethylenically unsaturated group was 285 g / mol, the acid value was 67 mg KOH / g, and the amount of residual GMA was 0.05% by mass.

Production Example 9 (Alkali-soluble Resin 9)
A solution of alkali-soluble resin 9 having a solid concentration of 29.5% by mass was obtained in the same manner as in Production Example 1 except that 40 g of N-benzylmaleimide (BzMI) was used instead of CHMI. Mw of the obtained alkali-soluble resin 9 was 40,000, the equivalent weight of the ethylenically unsaturated group was 350 g / mol, the acid value was 64 mg KOH / g, and the amount of remaining GMA was 0.05% by mass.

Production Example 10 (Production of Alkali-Soluble Resin 10)
A solution of alkali-soluble resin 10 having a solid concentration of 29.5% by mass was obtained in the same manner as in Production Example 1 except that 60 g of acrylic acid (AA) was used instead of MA. The Mw of the obtained alkali-soluble resin 10 was 40,000, the equivalent weight of the ethylenically unsaturated group was 350 g / mol, the acid value was 62 mg KOH / g, and the amount of remaining GMA was 0.05% by mass.

Production Example 11 (Alkali-soluble Resin 11)
A solution of alkali soluble resin 11 having a solid concentration of 29.5% by mass was obtained in the same manner as in Production Example 1 except that the stirring time at 110 ° C. was changed to 8 hours. Mw of the obtained alkali-soluble resin 1 was 40,000, the equivalent weight of the ethylenically unsaturated group was 350 g / mol, the acid value was 64 mg KOH / g, and the residual GMA ratio was 0.02 mass%.

Production Example 12 (Alkali-soluble Resin 12)
A solution of an alkali-soluble resin 12 was obtained in the same manner as in Production Example 1 except that the stirring time at 110 ° C. was changed to 5 hours. Mw of the obtained alkali-soluble resin 12 was 40,000, the ethylenically unsaturated group equivalent was 350 g / mol, the acid value was 64 mg KOH / g, and the residual GMA rate was 0.30 mass%.

Production Example 13 (Alkali-soluble Resin 13)
The solid content concentration is 28.5 mass% in the same manner as in Production Example 1 except that the blending amount of MA is 50 g, the blending amount of CHMI is 30 g, the blending amount of MMA is 0 g, and the blending amount of GMA is 65 g. The solution of alkali-soluble resin 13 was obtained. Mw of the obtained alkali-soluble resin 13 was 36,000, the equivalent weight of the ethylenically unsaturated group was 278 g / mol, the acid value was 93 mg KOH / g, and the amount of residual GMA was 0.05% by mass.

The compositions and evaluation results of Production Examples 1 to 13 are shown in Tables 1 and 2.

(Preparation of a substrate with black matrix)
A 1.0 μm-thick black matrix consisting of a composition containing a polyimide resin and carbon black on the surface of an alkali-free glass substrate (OA-10; manufactured by Nippon Electric Glass Co., Ltd .; 50 mm × 70 mm, thickness 0.7 mm) To form a black matrix-attached substrate.

(Fabrication of a substrate with a flattening film)
The black matrix-coated substrate produced by the above method is cleaned by exposure to light for 60 seconds using a UV / ozone apparatus (SSP 16-110; manufactured by Sen Special Light Source Co., Ltd.) and then planarized by spin coating. A coating film material (NN 901; manufactured by JSR Corp.) was applied and dried to form a transparent flattening film having a thickness of 1.5 μm. This was dried by heating (prebaked) at 90 ° C. for 10 minutes, and irradiated with ultraviolet light until the saturated exposure amount was reached. Next, 0.1% by mass of tetramethylammonium hydroxide (hereinafter, "TMAH") and 0.3% by mass of "Emulgen" (registered trademark) A-60 (hereinafter, "A-60"; Kao ( ) And using the aqueous solution at 23 ° C., and further washed with water to wash away the unexposed area of the planarized film. Then, the substrate was heat-dried (post-baked) at 230 ° C. for 30 minutes to prepare a substrate with a planarized film.

Evaluation in the examples and comparative examples was performed by the following method.

(Transparency of photosensitive resin composition)
Each example using a spin coater (type 1HD2) manufactured by Mikasa Co., Ltd. on the surface of an alkali-free glass substrate (OA-10; manufactured by Nippon Electric Glass Co., Ltd .; 50 mm × 70 mm, thickness 0.7 mm) And the photosensitive resin composition produced in the comparative example was apply | coated. After drying under reduced pressure for 200 seconds under the conditions of temperature: 25 ° C., pressure: 45 Pa, this is heat dried (prebaked) for 10 minutes in an oven (PERFECTOVEN PV-210; Tabai Espec Corp. product) set at 105 ° C. , And a pre-baked film. A substrate with a flattened film on which a pre-baked film has been formed is cooled to room temperature, and an ultraviolet ray exposure machine (PEM-6M; made by Union Optical Co., Ltd.) equipped with a glass UV filter (UV-35; made by Asahi Techno Glass Co., Ltd.) , Collimation angle θ: 2 °, i-line (365 nm) illuminance: 30 mW / cm ² ), without using a negative photomask, each wavelength of i-line: 365 nm, h-line: 405 nm and g-line: 436 nm It exposed by the exposure amount (i-line conversion) of 24 mJ / cm < ² > by using the ultraviolet-ray containing as an irradiation light.

Next, using an aqueous solution of 0.3% by mass of TMAH and 0.3% by mass of A-60 as a developing solution at 23 ° C., an automatic developing apparatus (AD-2000; manufactured by Mikasa Co., Ltd.) is used. It was shower developed, further washed with water and air dried. Next, it was heat-dried (post-baked) in an oven at 230 ° C. for 30 minutes to prepare a substrate with a 3.00 μm thick photo-spacer film.

The light transmittance at a wavelength of 400 to 700 nm is measured with a C light source using a microspectrometer (LCF-100MA: manufactured by Otsuka Electronics Co., Ltd.) for the central portion of the substrate with a photospacer solid film, and the following criteria The transparency of the photosensitive resin composition was evaluated by the following. I passed A.
A: Light transmittance at a wavelength of 400 to 700 nm is 80% or more.
B: Light transmittance at wavelengths of 400 to 700 nm is less than 80%.

(Viscosity of pre-baked film)
As a sample reproducing the viscosity characteristics of the pre-baked films obtained in Examples 1 to 13 and Comparative Examples 1 to 3, alkali-free glass substrates (OA-10; manufactured by Nippon Electric Glass Co., Ltd .; 50 mm × 70 mm, thickness 0) On the .7 mm), a pre-baked film was produced under the conditions of each example and comparative example. The obtained pre-baked film is collected 90 mm ³ or more using a spatula, measured using a rheometer (MCR-302; Anton Paar Co., Ltd. product) and a plate of φ 15 mm, measurement thickness: 0.5 mm, frequency: 1 Hz, strain The viscosity at 23 ° C. was measured while raising the temperature from 20 ° C. to 110 ° C. at a temperature rising rate of 0.083 ° C./sec under a condition of 0.5%.

(Surface shape of photo spacer)
The truncated cone shaped pattern photo spacers formed in Examples 1 to 13 and Comparative Examples 1 to 3 are magnified by 7,000 times using FE-SEM (S-4800; manufactured by Hitachi High-Technologies Corporation). It observed and the surface shape of the photo spacer was evaluated by the following references | standards. I passed A.
B: Irregularities are observed.
A: No unevenness is observed.

(Elastic recovery of photo spacer)
Using a hardness scale Fischer (Fischerscope H100; Helmut Fischer GmbH & Co.) and a flat indenter with a diameter of 50 μm for the frustoconical pattern photospacers formed in Examples 1 to 13 and Comparative Examples 1 to 3, the speed 2. A pressure was applied until the load reached 50 mN at 5 mN / sec and held for 5 seconds, and then a hysteresis curve was created when held at a speed of 2.5 mN / sec and held for 5 seconds after reaching 0 mN. The total deformation amount Ha [μm] and the plastic deformation amount Hb [μm] were obtained from the obtained hysteresis curve, and the elastic recovery factor ((Ha−Hb / Ha) × 100) of the photo spacer was calculated. The number average value measured about five places was computed, and the following standard evaluated. Passed AA, A and B
C: elastic recovery rate less than 70% B: elastic recovery rate 70% or more and less than 72% A: elastic recovery rate 72% or more and less than 73% AA: elastic recovery rate 73% or more.

(Evaluation of height variation of photo spacer in lens scan exposure)
In Examples 1 to 13 and Comparative Examples 1 to 3, in the range of 20 mm square in the substrate plane corresponding to the joint portion of the lens and the lens among the truncated cone shaped photo spacer formed by the lens scan exposure, the in-plane plane Select 20 photo spacers at regular intervals in the direction orthogonal to the direction in which multiple lenses are arranged in two rows, and measure the height variation (maximum height-minimum height) using the step measuring instrument The height variation of the photo spacer was evaluated according to the following criteria. I passed A and B.
C: variation in height is 0.04 μm or more B: variation in height is 0.02 μm or more and less than 0.04 μm A: variation in height is less than 0.02 μm.

(Evaluation of missing photo spacer in lens scan exposure)
Among the frustoconical pattern photo spacers formed in Examples 1 to 13 and Comparative Examples 1 to 3, 10,000 were observed with a microscope to determine the presence or absence of chipping. From the number of truncated conical pattern photo spacers in which chipping was recognized, evaluation was made according to the following criteria. Passed AA, A and B
C: 11 or more chips of photo spacer B: 6 to 10 chips of photo spacer A: 1 to 5 chips of photo spacer AA: 0 chips of photo spacer.

(Evaluation of height variation of photo spacer in proximity exposure multi-patterning)
In Examples 1 to 13 and Comparative Examples 1 to 3, among the truncated cone-shaped pattern photo spacers formed by proximity exposure multi-patterning, the height of the photo spacer formed in the first exposure and the photo spacer formed in the subsequent exposure About the difference with the height of a spacer, the height variation (maximum height-minimum height) was measured using the level difference measuring device, and the height variation of the photo spacer was evaluated by the following criteria. I passed A and B.
C: variation in height is 0.20 μm or more B: variation in height is 0.10 μm or more and less than 0.20 μm A: variation in height is less than 0.10 μm.

Example 1
(Preparation of Photosensitive Resin Composition 1)
Solution of alkali-soluble resin 1 having a solid content concentration of 29.5% by mass obtained by Production Example 1: 21.13 parts by mass, dipentaerythritol pentaacrylate ("KAYARAD" (registered trademark) DPHA; Nippon Kayaku; below, “DPHA”) (ethylenically unsaturated group equivalent 100): 11.58 parts by mass, photopolymerization initiator “Adeka Acrulus” (trademark registered) N-1919; hereinafter, “N1919”: 0.36 parts by mass, “ IRGACURE "(registered trademark) 907 (manufactured by BASF Japan Ltd.); hereinafter," IC 907 ": 0.89 parts by mass, 2,4-diethylthioxanthone (" KAYACURE "(registered trademark) DETX-S; Nippon Kayaku ( Co., Ltd .; hereafter, "DETX"): 0.89 parts by mass, surfactant "BYK" (registered trademark)-333 (manufactured by Bick Chemie Japan Co., Ltd.) The following "BYK-333") 0.03 parts by mass, polymerization inhibitor 2, 5-bis (1, 1, 3, 3- tetramethylbutyl) hydroquinone (Wako Pure Chemical Industries, Ltd.); ): 0.02 parts by mass and 65.10 parts by mass of propylene glycol monomethyl ether (PGME) were stirred at room temperature to obtain a photosensitive resin composition 1.

The substrate with a planarizing film obtained by the above-mentioned method is subjected to a cleaning treatment by exposure for 60 seconds using a UV / ozone apparatus (SSP 16-110; manufactured by Sen Special Light Source Co., Ltd.), and then a spin coater The photosensitive resin composition 1 was applied using (type 1HD2; manufactured by Mikasa Co., Ltd.). After drying under reduced pressure for 200 seconds under the conditions of temperature: 25 ° C., pressure: 45 Pa, heat drying (pre-baking) in an oven (PERFECTOVEN PV-210; Tabai Espec Corp.) for 10 minutes set at 105 ° C. It was cooled to form a pre-baked film.

Next, using the FX-65S (manufactured by Nikon Corporation) as a lens scan exposure apparatus, the i-line: 365 nm through a circular photomask with a diameter of 7 μm, using the planarizing film-attached substrate on which the pre-baked film has been formed. It exposed by the exposure amount (i-line conversion) of 30 mJ / cm < ² > by making the ultraviolet-ray containing each wavelength of h line | wire: 405 nm and g line | wire 436 nm into irradiation light.

Next, using an aqueous solution of 0.3% by mass of TMAH and 0.3% by mass of A-60 as a developing solution at 23 ° C., an automatic developing apparatus (AD-2000; manufactured by Mikasa Co., Ltd.) is used. It was shower developed, further washed with water and air dried. Finally, it was heat-dried (post-baked) in an oven at 230 ° C. for 30 minutes to produce a photospacer with an upper bottom 6 μm, a lower bottom 9 μm, and a height 3 μm.

Moreover, the ultraviolet exposure machine (PEM-6M; Union Optical Co., Ltd. product) which attached the glass-made UV filter (UV-35; Asahi Techno Glass Co., Ltd. product) to the substrate with a planarization film which formed the above-mentioned pre-baking film Using a negative photomask in which a circular pattern with a diameter of 10 μm is arranged at a pitch of 15 μm using a collimation angle θ = 2 °, i-line (365 nm) illuminance = 30 mW / cm 2); The first exposure was performed using ultraviolet light including 405 nm and g-line: 436 nm wavelengths. Subsequently, the negative photomask was shifted by a half pitch to perform subsequent exposure (proximity exposure multi-patterning).

Next, using an aqueous solution of 0.3% by mass of TMAH and 0.3% by mass of A-60 as a developing solution at 23 ° C., an automatic developing apparatus (AD-2000; manufactured by Mikasa Co., Ltd.) is used. It was shower developed, further washed with water and air dried. Finally, it was heat-dried (post-baked) in an oven at 230 ° C. for 30 minutes to produce a photospacer with an upper bottom 6 μm, a lower bottom 9 μm, and a height 3 μm.

(Examples 2 to 13, Comparative Examples 1 to 3)
A photosensitive resin composition, a pre-baked film and a photo spacer were produced in the same manner as in Example 1 except that the composition of the photosensitive resin composition was changed as shown in Table 2. The results evaluated in the same manner as in Example 1 are shown in Tables 3 to 5.

Here, “M520” in Tables 3 to 5 means the reaction product of a mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate with succinic anhydride (M520; manufactured by Toagosei Co., Ltd .; ethylenic unsaturated equivalent 104 g / Mol) is represented.

The transparent photosensitive resin composition of the present invention is suitably used as a material for forming a photo spacer of a liquid crystal display by lens scan exposure.

Claims (17)

1. A transparent photosensitive resin composition comprising at least an alkali soluble resin, a photopolymerization initiator and a polymerizable monomer, wherein the alkali soluble resin is A) a structural unit represented by the following general formula (1):
   B) Structural units represented by the following general formula (2):
   C) having a structural unit represented by the following general formula (3),
   The transparent photosensitive resin composition whose ethylenically unsaturated group equivalent of the said alkali-soluble resin is 400 g / mol or less.
   

   

   (In the above general formula (1), R ¹ represents a hydrogen atom or a methyl group.)
   

   

   (In the above general formula (2), R ² and R ³ each independently represent a hydrogen atom or a methyl group. X represents —CH ₂ CH (OH) CH ₂ O (C = O) —, —CH ₂ CH _{2 NH (C = O) O (} CH 2) m O (C = O) - or _{- (CH 2) n O (} C = O) NHCH 2 CH 2 O (C = O) -. shows the proviso, m and each n independently represents an integer of 1 to 4)
   

   

   (In the above general formula (3), Y represents an aryl group having 6 to 11 carbon atoms which may have a substituent, an aralkyl group having 7 to 10 carbon atoms which may have a substituent, or a substituent Indicates an optionally substituted cycloalkyl group having 3 to 10 carbon atoms.)
2. The transparent photosensitive resin composition according to claim 1, wherein in the general formula (3), Y is a cycloalkyl group having 3 to 10 carbon atoms which may have a substituent.
3. The transparent photosensitive resin composition according to claim 1 or 2, wherein in the general formula (3), Y is a cyclohexyl group.
4. The transparent photosensitive resin composition according to any one of claims 1 to 3, wherein in the general formula (1), R ¹ is a methyl group.
5. The transparent photosensitive material according to any one of claims 1 to 4, wherein the amount of structural unit represented by the general formula (3) is 10 to 23 mol% when the total amount of structural units of the alkali-soluble resin is 100 mol%. Resin composition.
6. The transparent photosensitive resin composition according to any one of claims 1 to 5, wherein the weight average molecular weight of the alkali-soluble resin is 10,000 to 100,000.
7. The transparent photosensitive resin composition according to any one of claims 1 to 6, wherein the acid value of the alkali-soluble resin is 60 to 100 mg KOH / g.
8. The transparent photosensitive resin composition according to any one of claims 1 to 7, which contains 34 to 66 parts by mass of the alkali-soluble resin relative to 100 parts by mass of the polymerizable monomer.
9. After curing, it is applied to a film thickness of 3 μm, dried under reduced pressure at 25 ° C and 45Pa for 200 seconds, and dried by heating in an oven at 105 ° C for 10 minutes. The viscosity at 23 ° C is 1 × 10 ³ to 1 × The transparent photosensitive resin composition according to any one of claims 1 to 8, which is 10 ⁸ Pa · s.
10. A frustum-shaped photospacer having a diameter of 6 μm at the upper base and a diameter of 9 μm at the lower base and a height of 3 μm is formed, and the elastic recovery rate when a load of 50 mN is applied is 70% or more. The transparent photosensitive resin composition as described in any one of 9.
11. The transparent photosensitive resin composition according to any one of claims 1 to 10 for lens scan exposure.
12. A photo spacer using a cured product of the transparent photosensitive resin composition according to any one of claims 1 to 11.
13. A liquid crystal display device using the photo spacer according to claim 12.
14. A transparent photosensitive resin composition according to any one of claims 1 to 11 is coated on a substrate and dried to obtain a pre-baked film, and the pre-baked film is subjected to lens scan exposure and development to form a photo spacer. How to make a photo spacer.
15. The method for producing a photo spacer according to claim 14, wherein the viscosity at 23 ° C of the pre-baked film is 1 × 10 ³ to 1 × 10 ⁸ Pa · s.
16. A method of manufacturing a liquid crystal display device, wherein a color filter substrate and a drive element side substrate are opposed to each other and a liquid crystal compound is sealed between the two, and the method is applied to the color filter substrate and / or the drive element side substrate. Or the manufacturing method of a liquid crystal display device which has the process of manufacturing a photo spacer by the manufacturing method of 15 statement.
17. A transparent photosensitive resin composition comprising at least an alkali soluble resin, a photopolymerization initiator and a polymerizable monomer, wherein the alkali soluble resin is A) a structural unit represented by the following general formula (1):
    B) Structural units represented by the following general formula (2):
    C) having a structural unit represented by the following general formula (3),
    Use of a transparent photosensitive resin composition in which the ethylenically unsaturated group equivalent of the alkali-soluble resin is 400 g / mol or less for lens scan exposure.
    

    

    (In the above general formula (1), R ¹ represents a hydrogen atom or a methyl group.)
    

    

    (In the above general formula (2), R ² and R ³ each independently represent a hydrogen atom or a methyl group. X represents —CH ₂ CH (OH) CH ₂ O (C = O) —, —CH ₂ CH _{2 NH (C = O) O (} CH 2) m O (C = O) - or _{- (CH 2) n O (} C = O) NHCH 2 CH 2 O (C = O) -. shows the proviso, m and each n independently represents an integer of 1 to 4)
    

    

    (In the above general formula (3), Y represents an aryl group having 6 to 11 carbon atoms which may have a substituent, an aralkyl group having 7 to 10 carbon atoms which may have a substituent, or a substituent Indicates an optionally substituted cycloalkyl group having 3 to 10 carbon atoms.)

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