KR20070121544A - Photosensitive resin composition and bump for controlling liquid crystal alignment using the same - Google Patents

Abstract

A photosensitive resin composition is provided to form a good pattern in alkali development after exposure by restricting an acid number of a photopolymerizable compound within a predetermined range. A photosensitive resin composition is installed within a liquid crystal cell of a plurally divided vertical alignment mode, and forms a bump for controlling alignment of liquid crystals. The photosensitive resin composition contains (A) a photopolymerizable compound, (B) a photopolymerization initiator, and (C) a pigment. The photopolymerizable compound(A) has an acid number of 40-160 mg KOH/g. The pigment is contained in an amount of 10-60% by mass based on the total solid components except solvent.

Description

PHOTOSENSITIVE RESIN COMPOSITION AND BUMP FOR CONTROLLING LIQUID CRYSTAL ALIGNMENT USING THE SAME}

The present invention relates to a photosensitive resin composition which forms a bump provided in a liquid crystal cell of a multi-division vertical alignment system, and a bump for liquid crystal alignment using the same.

In general, among the image display apparatuses displaying the image information on the screen, the CRT (CRT) is the most used so far, which has a large inconvenience compared to the display area because the volume is large and heavy. For this reason, even if the display area is large, the thickness thereof is thin, and a liquid crystal display (LCD) that can be conveniently used in any place has been developed, and is gradually changing from the CRT display.

The liquid crystal display device has a structure in which two glass substrates are opposed to each other and fixed, and a liquid crystal is sealed therebetween. A transparent common electrode is formed on one glass substrate, and a plurality of transparent pixel electrodes are formed in a matrix on the other glass substrate, and a circuit for applying a voltage to each pixel electrode is formed separately.

However, the liquid crystal display device has a problem that the viewing angle is narrow because the display is embedded in the polarizing plate.

In order to widen the viewing angle, an IPS (In Plane Swiching) method, a VA (Vertical Alignment) method, and the like have been proposed. However, even in the VA system, when halftones are displayed, the viewing angle is narrowed because the liquid crystals face the same direction obliquely.

Here, in order to solve the viewing angle problem in the halftone of the VA system, an MVA (Multi-domain VA) system has been proposed (see, for example, Japanese Patent Laid-Open No. 2004-252480). This is a method of forming domain regulating means for regulating the orientation directions of the liquid crystals which are oriented obliquely when the voltage is applied to be in different directions in different domains in one pixel. The domain regulating means may be provided on at least one of the two substrates, and the at least one domain regulating means has a slope. In addition, projections are provided as domain regulating means having a slope. As the formation method of this protrusion, the formation method using a positive resist is described.

Moreover, the formation method of the processus | protrusion using the negative resist which does not worry about the film thickness reduction by image development is also proposed (for example, refer Unexamined-Japanese-Patent No. 2003-330011).

However, the projections described in these prior art documents are usually colorless. Therefore, the light is diffusely reflected in the projections, thereby causing a problem such as display stains.

In order to prevent diffuse reflection of light, it has been studied to color the liquid crystal alignment control bumps (hereinafter also referred to as "bumps") and absorb light using a photosensitive resin composition to which a pigment is added.

In addition, it has been found that the cross-sectional shape is important for the bumps to orient the liquid crystal. However, the photosensitive resin composition containing a pigment has a problem that it is difficult to make the bump formed from this photosensitive resin composition into a desired shape.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, the inventors carried out detailed study focusing on the photopolymerizable compound contained in the photosensitive resin composition. As a result, the inventors have found that the above problems can be solved by using a specific photopolymerizable compound, and have completed the present invention. More specifically, the present invention provides the following.

A first invention of the present invention is a photosensitive resin composition which is provided in a liquid crystal cell of a multi-division vertical alignment method and forms bumps for controlling the alignment of liquid crystals. The photosensitive resin composition comprises a photopolymerizable compound (A) and a photopolymerization. It contains an initiator (B) and a pigment (C), The acid value of the said photopolymerizable compound (A) is 40 mg / g or more and 160 mg / g or less, The said pigment is 10 mass% or more with respect to the total solid other than a solvent 60 It is a photosensitive resin composition which is the mass% or less.

Moreover, 2nd invention of this invention is liquid crystal orientation control bump formed by the said photosensitive resin composition.

EMBODIMENT OF THE INVENTION Hereinafter, the Example of this invention is described. The photosensitive resin composition which forms the bump for controlling the orientation of the liquid crystal concerning this invention contains a photopolymerizable compound (A), a photoinitiator (B), and a pigment (C).

[Photopolymerizable compound (A)]

As a photopolymerizable compound (A) in this invention, the compound which has at least 1 or more of ethylenically unsaturated double bond is mentioned.

<Compounds having ethylenically unsaturated double bonds>

Examples of the compound having an ethylenically unsaturated double bond include acrylic acid, methacrylic acid, fumaric acid, maleic acid, monomethyl fumaric acid, monoethyl fumarate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and ethylene glycol monomethyl Ether acrylate, ethylene glycol monomethyl ether methacrylate, ethylene glycol monoethyl ether acrylate, ethylene glycol monoethyl ether methacrylate, glycerol acrylate, glycerol methacrylate, acrylic acid amide, methacrylic acid amide, acrylonitrile , Methacrylonitrile, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, isobutyl acrylate, isobutyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, Benzyl acrylate, benzyl methacrylate, ethylene glycol diac Ethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, butylene glycol di Methacrylate, propylene glycol diacrylate, propylene glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, tetramethylolpropane tetraacrylate, tetramethylolpropane tetramethacrylate, penta Erythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, dipentaerythritol hexaacrylate Monomers and oligomers such as yate, dipentaerythritol hexamethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, and cardoepoxy diacrylate; Polyester (meth) acrylate obtained by reacting (meth) acrylic acid with a polyester prepolymer obtained by condensing polyhydric alcohols with monobasic acid or polybasic acid; Polyurethane (meth) acrylates obtained by reacting a compound having a polyol group and two isocyanate groups and then reacting (meth) acrylic acid; And bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol or cresol novolak type epoxy resin, resol type epoxy resin, triphenol methane type epoxy resin, polycarboxylic acid polyglycidyl ester, polyol poly And epoxy (meth) acrylate resins obtained by reacting (meth) acrylic acid with epoxy resins such as glycidyl esters, aliphatic or alicyclic epoxy resins, amine epoxy resins, and dihydroxybenzene type epoxy resins. Moreover, resin which made polybasic acid anhydride react with the said epoxy (meth) acrylate resin can also be used. In view of the introduction of acryloyl or methacryloyl groups into these compounds, the crosslinking efficiency in the coating film is increased, and the coating film is excellent in light resistance and chemical resistance.

The acid value of the photopolymerizable compound is KOH 40 mg / g or more and 160 mg / g or less, preferably KOH 60 mg / g or more and 140 mg / g or less. By using a photopolymerizable compound having an acid value of KOH 40 mg / g or more, a better pattern than alkali development can be formed. In addition, by using the photopolymerizable compound whose acid value is 160 mg / g or less, pattern peeling does not generate | occur | produce also by alkali development. That is, a favorable pattern can be formed by making the acid value of a photopolymerizable compound into the said range.

Moreover, it is preferable to use the compound which has the said ethylenically unsaturated double bond whose mass mean molecular weight is 1,000 or more. By making a mass average molecular weight 1,000 or more, a coating film can be made uniform. Moreover, it is preferable to make mass average molecular weight 100,000 or less. Developability can be made favorable by making a mass mean molecular weight 100,000 or less. In this invention, the compound which has an ethylenically unsaturated double bond whose mass mean molecular weight is 1,000 or more is called the high molecular compound which has an ethylenically unsaturated double bond.

Moreover, it is preferable to use the high molecular compound which has the said ethylenically unsaturated double bond in combination with a photopolymerizable monomer. As this photopolymerizable monomer, methyl acrylate, methyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, ethylene glycol diacrylate, ethylene glycol di Methacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, propylene glycol diacrylate, propylene glycol dimethacrylate, trimethylolpropane Triacrylate, trimethylolpropane trimethacrylate, tetramethylolpropane tetraacrylate, tetramethylolpropane tetramethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pentaerythritol tetraacrylate, Pentaerythritol tetrametha Relate, dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, 1,6-hexanediol diacrylate, benzyl acrylate, benzyl methacrylate The rate, cardoepoxy diacrylate, acrylic acid, methacrylic acid, etc. are mentioned, It is not limited to these. Among these photopolymerizable monomers, polyfunctional photopolymerizable monomers are preferable. By combining the polymer compound having an ethylenically unsaturated double bond with the photopolymerizable monomer in this manner, the curability can be improved and the pattern formation can be facilitated.

In the above, the polymer compound which has ethylenically unsaturated double bond was mentioned as a photopolymerizable compound. In this invention, the mixture of a polymeric binder and a photopolymerizable monomer shall also be included in a photopolymerizable compound. In this case, the acid value of the polymeric binder is KOH 40 mg / g or more and 160 mg / g or less, preferably KOH 60 mg / g or more and 140 mg / g or less. By using the photopolymerizable compound whose acid value is KOH 40 mg / g or more, a pattern better than alkali image development can be formed. In addition, by using the photopolymerizable compound whose acid value is 160 mg / g or less, pattern peeling does not arise also by alkali image development. That is, a favorable pattern can be formed by making the acid value of a photopolymerizable compound into the said range.

Specific examples of the polymer binder include monomers having carboxyl groups such as acrylic acid and methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, 2-hydroxyethyl acrylate, and 2-hydroxyethyl. Methacrylate, 2-hydroxypropyl methacrylate, N-butyl acrylate, N-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, benzyl acrylate, benzyl methacrylate, phenoxyacrylic Copolymers of latex, phenoxy methacrylate, isobornyl acrylate, isobornyl methacrylate, glycidyl methacrylate, styrene, acrylamide, and acrylonitrile, and phenol novolac type epoxy acrylate Polymer, phenol novolak type epoxy methacrylate polymer, cresol novolak type epoxy acrylate polymer, cresol novolak type When there may be mentioned a resin having a methacrylate polymer, a bisphenol A type epoxy acrylate polymer, and a bisphenol S type epoxy acrylate polymer. As for content of the monomer component which has carboxyl groups, such as acrylic acid and methacrylic acid which comprise the said resin, the range of 5 mol% or more and 40 mol% or less is preferable.

The range with preferable mass average molecular weight of the said polymeric binder is 1,000 or more and 100,000 or less. By making a mass average molecular weight 1,000 or more, a coating film can be formed uniformly. Moreover, developability can be made favorable by making a mass mean molecular weight 100,000 or less.

When a polymeric binder and a photopolymerizable monomer are included as a photopolymerizable compound, it is preferable that a polymeric binder is mix | blended in the range of 10 mass parts or more and 60 mass parts or less per 100 mass parts of total amounts of a polymeric binder, a photopolymerizable monomer, and a photoinitiator. . By making the said compounding quantity 10 mass parts or more, a film can be easily formed at the time of application | coating and drying of the photosensitive resin composition of this invention, and the film strength after hardening can fully be raised. Moreover, developability can be made favorable by carrying out compounding quantity to 60 mass parts or less.

Moreover, it is preferable to mix | blend a photopolymerizable monomer in the range of 15 mass parts or more and 50 mass parts or less per 100 mass parts of total amounts of a polymeric binder, a photopolymerizable monomer, and a photopolymerization initiator. By making the said compounding quantity 15 mass parts or more, the photocuring defect can be prevented and sufficient heat resistance and chemical-resistance can be obtained. In addition, when the blending amount is 50 parts by mass or less, the coating film forming ability can be improved.

[Photopolymerization Initiator (B)]

As a photoinitiator, for example, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- [4- (2-hydroxyethoxy) phenyl]- 2-hydroxy-2-methyl-1-propan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- (4-ddecylphenyl) 2-hydroxy-2-methylpropan-1-one, 2,2-dimethoxy-1,2-diphenylethan-1-one, bis (4-dimethylaminophenyl) ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-monopolynopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-monopolynophenyl) -butan-1-one, ethanone , 1- [9-ethylene-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -1- (O-acetyloxime), 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 4-benzoyl-4'-methyldimethylsulfide, 4-dimethylamino benzoic acid, 4-dimethylamino benzoic acid methyl, 4-dimethylamino benzoic acid ethyl, 4-dimethylamino benzoic acid butyl, 4-dimethylamino-2-ethylhexyl benzoic acid, 4 Dime Amino-2-isoamyl benzoic acid, benzyl-β-methoxyethylacetal, benzyldimethyl ketal, 1-phenyl-1,2-propanedione-2- (O-ethoxycarbonyl) oxime, methyl O-benzoyl benzoate, 2,4-diethyl thioxanthone, 2-chloro thioxanthone, 2,4-dimethyl thioxanthone, 1-chloro-4-propoxy thioxanthone, thioxanthene, 2-chloro thioxanthene, 2,4-diethylthioxanthene, 2-methylthioxanthene, 2-isopropylthioxanthene, 2-ethylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-diphenyl Anthraquinone, azobisisobutyronitrile, benzoylperoxide, cumeneperoxide, 2-mercaptobenzoimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2- (o-chlorophenyl) -4,5-di (m-methoxyphenyl) -imidazolyl dimer, benzophenone, 2-chlorobenzophenone, p, p'-bisdimethylaminobenzophenone, 4,4'-bisdiethylaminobenzo Phenone, 4,4'-dichlorobenzophenone, 3,3-dime -4-methoxy benzophenone, benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, benzoin butyl ether, acetophenone , 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, dichloroacetophenone, trichloroacetophenone, p-tert-butylacetophenone, p-dimethylaminoacetophenone, p- tert-butyltrichloroacetophenone, p-tert-butyldichloroacetophenone, α, α-dichloro-4-phenoxyacetophenone, thioxanthone, 2-methylthioxanthone, 2-isopropyl thioxanthone, di Benzosuberone, pentyl-4-dimethylaminobenzoate, 9-phenylacridine, 1,7-bis- (9-acridinyl) heptane, 1,5-bis- (9-acridinyl ) Heptane, 1,3-bis- (9-acridinyl) propane, p-methoxytriazine, 2,4,6-tris (trichloromethyl) -s-triazine, 2-methyl-4,6 -Bis (trichloro Methyl) -s-triazine, 2- [2- (5-methylfuran-2-yl) ethenyl] -4,6-bis (trichloromethyl) -s-triazine, 2- [2- (furan -2-yl) ethenyl] -4,6-bis (trichloromethyl) -s-triazine, 2- [2- (4-diethylamino-2-methylphenyl) ethenyl] -4,6-bis (Trichloromethyl) -s-triazine, 2- [2- (3,4-dimethoxyphenol) ethenyl] -4,6-bis (trichloromethyl) -s-triazine, 2- (4- Methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-ethoxystyryl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-n-butoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-bis-trichloromethyl-6- (3-bromo-4-methoxy) phenyl -s-triazine, 2,4-bis-trichloromethyl-6- (2-bromo-4-methoxy) phenyl-s-triazine, 2,4-bis-trichloromethyl-6- (3 -Bromo-4-methoxy) styrylphenyl-s-triazine, and 2,4-bis-trichloromethyl-6- (2-bromo-4-methoxy) styrylphenyl-s-triazine Etc. can be mentioned. You may use these photoinitiators individually or in combination of 2 or more types.

It is preferable that this photoinitiator is contained 1 mass part or more and 40 mass parts or less with respect to 100 mass parts of total amounts of the said photopolymerizable compound and a photoinitiator.

Pigment (C)

The photosensitive resin composition according to the present invention contains a pigment. Colored bumps can be formed by using the photosensitive resin composition containing this pigment. Therefore, the diffused reflection of light can be prevented by this colored bump. As the pigment, any of an inorganic pigment and an organic pigment can be used. It is preferable to use organic pigments from the viewpoint of lowering the dielectric constant of the formed bumps among the pigments.

(Organic Pigments)

As organic pigments, compounds classified as pigments in the color index (CI: The Society of Dyers and Colourists, Inc.) can be used. Specifically, compounds having the following color index (CI) numbers are used. Can be used.

C.I. Pigment Yellow 1 (hereinafter 'CI Pigment Yellow' is the same and only numbers are listed), 3, 11, 12, 13, 14, 15, 16, 17, 20, 24, 31, 53, 55, 60, 61, 65, 71, 73, 74, 81, 83, 86, 93, 95, 97, 98, 99, 100, 101, 104, 106, 108, 109, 110, 113, 114, 116, 117, 119, 120, 125, 126, 127, 128, 129, 137, 138, 139, 147, 148, 150, 151, 152, 153, 154, 155, 156, 166, 167, 168, 175, 180, 185;

C.I. Pigment Orange 1 (hereinafter 'CI Pigment Orange' is the same and only numbers are listed), 5, 13, 14, 16, 17, 24, 34, 36, 38, 40, 43, 46, 49, 51, 55 59, 61, 63, 64, 71, 73;

C.I. Pigment Violet 1 (hereinafter 'C.I. Pigment Violet' is the same and lists only the numbers), 19, 23, 29, 30, 32, 36, 37, 38, 39, 40, 50;

C.I. Pigment Red 1 (hereinafter 'CI Pigment Red' is the same and only numbers are listed), 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17 , 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 40, 41, 42, 48: 1, 48: 2, 48: 3, 48: 4, 49: 1, 49: 2 , 50: 1, 52: 1, 53: 1, 57, 57: 1, 57: 2, 58: 2, 58: 4, 60: 1, 63: 1, 63: 2, 64: 1, 81: 1 , 83, 88, 90: 1, 97, 101, 102, 104, 105, 106, 108, 112, 113, 114, 122, 123, 144, 146, 149, 150, 151, 155, 166, 168, 170 , 171, 172, 174, 175, 176, 177, 178, 179, 180, 185, 187, 188, 190, 192, 193, 194, 202, 206, 207, 208, 209, 215, 216, 217, 220 , 223, 224, 226, 227, 228, 240, 242, 243, 245, 254, 255, 264, 265;

C.I. Pigment Blue 1 (hereinafter 'C.I. Pigment Blue' is the same and lists only the numbers), 2, 15, 15: 3, 15: 4, 15: 6, 16, 22, 60, 64, 66;

C.I. Pigment Green 7, C.I. Pigment Green 36, C.I. Pigment green 37;

C.I. Pigment Brown 23, C.I. Pigment Brown 25, C.I. Pigment Brown 26, C.I. Pigment brown 28;

C.I. Pigment Black 1, C.I. Pigment Black 7.

The organic pigments are preferably used in combination of at least two organic pigments, and more preferably in combination of three or more organic pigments. Moreover, it is more preferable to use this organic pigment combining organic pigment so that it may become black by color mixing. By using two or more organic pigments or three or more organic pigments, the wavelength range of light to be absorbed becomes wider, so that diffuse reflection of light can be further prevented.

Preferred among organic pigments, C.I. Pigment blue 15: 6, C.I. Pigment red 177, and C.I. Pigment yellow 139. The organic pigment in the present invention is preferably used in combination of two or more of these three organic pigments in terms of absorbing light, and it is particularly preferable to use all three kinds.

(Inorganic pigment)

As an inorganic pigment, if it is a pigment with light-shielding property, it will not specifically limit but can be used. Specific examples thereof include metal oxides such as carbon black, titanium black, copper, iron, manganese, cobalt, chromium, nickel, zinc, calcium and silver, composite oxides, metal sulfides, metal sulfates, and metal carbonates. Among these black pigments, it is more preferable to use carbon black having low cost and high light shielding properties.

As carbon black, well-known carbon black, such as channel black, furnace black, thermal black, and lamp black, can be used. It is also preferable to use resin coated carbon black. By this resin-coated carbon black, the dielectric constant of the light shielding film formed can be further reduced.

As the dispersant, it is preferable to use a polymer dispersant of polyethyleneimine, urethane resin, and acrylic resin.

As these dispersing agents, for example, the brand name BYK-161, 162, 163, 164, 166, 170, 182, and the brand name Sol Spas S3000, S9000, S17000, S20000, S27000, S24000 manufactured by Vikchem Japan Co., Ltd. , S26000, S28000, and the like.

(Content of pigment)

It is preferable that it is 10 mass% or more and 60 mass% or less with respect to total solids other than a solvent, and, as for content of a pigment, it is more preferable that they are 15 mass% or more and 40 mass% or less. When the content of the pigment is 10% by mass or more, the formed bumps sufficiently absorb light and do not cause diffuse reflection. Moreover, when it is 60 mass% or less, coloring is not too strong, the brightness | luminance of the screen in the liquid crystal display device which has the bump formed from the photosensitive resin composition of this invention is maintained favorable, and it is not difficult to form a pattern.

In addition, it is preferable that content of the said pigment is adjusted so that OD value per 1 micrometer of film thickness in the bump formed from the photosensitive resin composition of this invention may be 0.6 or more. If it is in the range of the said OD value, reflection of the light from a bump can be prevented.

[Other Ingredients]

In the photosensitive resin composition which concerns on this invention, an additive can be mix | blended as needed. Specific examples include sensitizers, curing accelerators, photocrosslinkers, photosensitizers, dispersants, dispersion aids, fillers, adhesion promoters, antioxidants, ultraviolet absorbers, anticoagulants, thermal polymerization inhibitors, antifoaming agents, and surfactants. .

In the photosensitive resin composition according to the present invention, a solvent for dilution may be added.

Here, as a solvent which can be added to the photosensitive resin composition, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol mono Methyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, Propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-n-butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene Glycol mono-n-butyl ether, tripropylene glycol monomethyl ether, and tripropylene Recall monoethyl ether and (poly) alkylene glycol monoalkyl ether; (Poly) alkyl such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate Lenglycol monoalkyl ether acetates; Other ethers such as diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, and tetrahydrofuran; Ketones such as methyl ethyl ketone, cyclohexanone, 2-heptanone, and 3-heptanone; Lactic acid alkyl esters such as methyl 2-hydroxypropionate and ethyl 2-hydroxypropionate; Ethyl 2-hydroxy-2-methylpropyl, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl ethoxy acetate, ethyl hydroxy acetate, 2-hydroxy-3-methylbutyrate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutylpropionate, ethyl acetate, n-propyl acetate , I-propyl acetate, n-butyl acetate, i-butyl acetate, n-pentyl acetate, i-pentyl acetate, n-butyl propionate, ethyl butyrate, n-propyl butyrate, i-propyl butyrate, i-propyl butyrate, n-butyl, pyruvic acid Other esters such as methyl, ethyl pyruvate, n-propyl pyruvate, methyl acetoacetate, ethyl acetoacetate, and ethyl 2-oxobutanoate; Aromatic hydrocarbons such as toluene and xylene; And amides such as N-methylpyrrolidone, N, N-dimethylformamide, and N, N-dimethylacetamide. These solvents can be used individually or in mixture of 2 or more types.

Among the above solvents, propylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, cyclohexanone, and 3- Methoxybutyl acetate is preferable because it shows excellent solubility with respect to a photopolymerizable compound and a photoinitiator, and can make the dispersibility of insoluble components, such as a pigment, favorable, and is propylene glycol monomethyl ether acetate, and 3-meth Particular preference is given to using oxybutyl acetate. A solvent can be used in 50 mass parts or more and 500 mass parts or less with respect to 100 mass parts of total amounts of a photopolymerizable compound, a photoinitiator, and a coloring agent.

As a manufacturing method of the photosensitive resin composition which concerns on this invention, it can obtain by mixing all the components, such as a pigment, a photopolymerizable compound, and a photoinitiator, mentioned above in a stirrer. In addition, you may filter using a filter so that the obtained mixture may become uniform.

It is preferable to set the film thickness of the liquid crystal alignment control bump formed on the board | substrate within the range of 1.0 micrometer-2.0 micrometers normally. On the other hand, the 'film thickness' refers to the maximum film thickness of the bump.

The profile angle of the liquid crystal alignment control bumps is preferably 10 ° or more and 55 ° or less, more preferably 15 ° or more and 40 ° or less. By carrying out a profile angle in the said range, a liquid crystal can be made into a desired orientation and the viewing angle of a display can be widened.

In addition, a "profile angle" means the angle which the tangent in the cross section of the board | substrate surface and the formed pattern makes.

<Formation of Bump for Liquid Crystal Alignment Control>

First, the photosensitive resin composition according to the present invention is applied onto a substrate using a contact transfer type coating device such as roll coating, reverse coating, and bar coating, or a non-contact type coating device such as a spinner (rotary coating device), and curtain flow coating. . Although it does not specifically limit as a board | substrate, For example, a glass plate, a quartz plate, a transparent or translucent resin plate, etc. are mentioned.

After apply | coating this photosensitive resin composition, it dries to remove a solvent and forms the photosensitive resin layer. The drying method is not particularly limited, and for example, (1) a method of drying for 60 seconds to 120 seconds at a temperature of 80 ° C or more and 120 ° C or less, preferably 90 ° C or more and 100 ° C or less on a hot plate, (2) You may use either the method of leaving to stand at room temperature for several hours, and (3) the method of removing a solvent by putting in a warm air heater or an infrared heater for ten to several minutes.

Subsequently, active energy rays, such as an ultraviolet-ray and an excimer laser beam, are irradiated through a negative mask to partially expose a photosensitive resin layer. Energy dose of irradiation is different according to the composition of the photosensitive resin composition, for example, it is preferred from 30mJ / cm ² around 2000mJ / cm ^2.

Subsequently, the photosensitive resin layer after exposure is patterned with a developing solution to pattern the desired shape. The image development method is not specifically limited, For example, an immersion method, a spray method, etc. can be used. As a developing solution, organic-type things, such as monoethanolamine, diethanolamine, and triethanolamine, and aqueous solution, such as sodium hydroxide, potassium hydroxide, sodium carbonate, ammonia, and a quaternary ammonium salt, are mentioned.

Next, the pattern after development is post-baked at about 200 degreeC. By the above method, a bump for liquid crystal alignment control having a predetermined shape can be formed.

Synthesis Example 1

56 parts by mass of benzyl methacrylate, 36 parts by mass of 2-hydroxyethyl methacrylate, and 78 parts by mass of glycidyl methacrylate are dissolved in 250 parts by mass of ethylene glycol monomethyl ether acetate, and azobisisobutyronitrile 2 mass parts were added and heat-polymerized.

Then, 40 mass parts of acrylic acid which melt | dissolved 2 mass parts of methylhydroquinone as a polymerization inhibitor was added and reacted. Subsequently, 42 mass parts of tetrahydrophthalic anhydrides were added and reacted, and resin was obtained. The mass average molecular weight of the obtained resin was 3000, and the acid value was KOH 112 mg / g.

(Example 1)

C.I. Pigment Red 177 10 parts by mass, C.I. Pigment blue 15: 6 15 parts by mass, C.I. Pigment Yellow 139 10 parts by mass and 7 parts by mass of a polymer dispersant (product name: Solspas 24000, manufactured by Avecia) were dispersed in 3-methoxybutyl acetate to prepare Pigment Dispersion A having a solid content concentration of 15% by mass.

30 parts by mass of the resin synthesized in Synthesis Example 1, 20 parts by mass of dipentaerythritol hexaacrylate (DPHA), and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane-1 as a polymerization initiator 10 parts by mass (product name: Ilgacure 369, manufactured by Chiba Specialty Chemical Co., Ltd.) and 20 parts by mass of the above-mentioned pigment dispersion A were dissolved, dissolved in propylene glycol monomethyl ether acetate (PGMEA), and the solid concentration was 20% by mass. It adjusted so that the photosensitive resin composition was produced.

(Example 2)

30 parts by mass of the resin synthesized in Synthesis Example 1, 20 parts by mass of dipentaerythritol hexaacrylate (DPHA), and 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane- as a polymerization initiator. 10 parts by mass of 1-one (product name: Ilgacure 369, manufactured by Chiba Specialty Chemicals), and carbon black dispersion (product name: RB (22% carbon black content, solvent 3-methoxybutyl acetate), manufactured by Mikuni Color) 20 A mass part was mixed, it melt | dissolved in propylene glycol monomethyl ether acetate (PGMEA), and it adjusted so that solid content concentration might be 20 mass%, and the photosensitive resin composition was produced.

(Comparative Example 1)

102 parts by mass of methyl methacrylate, 29 parts by mass of 2-hydroxyethyl methacrylate, and 95 parts by mass of glycidyl methacrylate are dissolved in 250 parts by mass of ethylene glycol monomethyl ether acetate, and azobisisobutyronitrile 2 mass parts were added and heat-polymerized.

Then, 47 mass parts of acrylic acid which melt | dissolved 2 mass parts of methylhydroquinone as a polymerization inhibitor was added and reacted. Subsequently, 15 mass parts of tetrahydrophthalic anhydrides were added, and it was made to react, and resin was obtained. The mass average molecular weight of obtained resin was 35000, and the acid value was KOH 37 mg / g. 30 parts by mass of this resin, 20 parts by mass of dipentaerythritol hexaacrylate (DPHA), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one (polymer name) as a polymerization initiator : 10 parts by mass of Monocure 369, manufactured by Chivas Specialty Chemicals Co., Ltd., and 20 parts by mass of the above-mentioned pigment dispersion A were dissolved, dissolved in propylene glycol monomethyl ether acetate (PGMEA), and adjusted to a solid content concentration of 20% by mass. A resin composition was prepared.

(Comparative Example 2)

56 parts by mass of 2-hydroxyethyl methacrylate and 50 parts by mass of acrylic acid were dissolved in 250 parts by mass of ethylene glycol monomethyl ether acetate, and 2 parts by mass of azobisisobutyronitrile was added to heat polymerization.

Then, 95 mass parts of glycidyl methacrylates which melt | dissolved 2 mass parts of methylhydroquinones as a polymerization inhibitor were added and reacted. Subsequently, 61 mass parts of tetrahydrophthalic anhydrides were added, and it was made to react, and resin was obtained. The mass average molecular weight of obtained resin was 19000, and the acid value was KOH 161 mg / g. 30 parts by mass of this resin, 20 parts by mass of dipentaerythritol hexaacrylate (DPHA), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one (polymer name) as a polymerization initiator : 10 parts by mass of Monocure 369, manufactured by Chivas Specialty Chemicals, and 20 parts by mass of carbon black dispersion (product name: RB, manufactured by Mikuni Color) were dissolved in propylene glycol monomethyl ether acetate (PGMEA) to obtain a solid content concentration. It adjusted so that it might be 20 mass%, and the photosensitive resin composition was produced.

[Method of forming bump for liquid crystal alignment control]

On the glass substrate on which the indium tin oxide (ITO) film was formed, the photosensitive resin composition was apply | coated using a spin coater, and it dried at 90 degreeC for 2 minutes, and formed the photosensitive resin layer. Subsequently, ultraviolet rays of an energy dose of 50 mJ / cm ² were selectively irradiated through a negative mask, and partially exposed. Next, it developed using tetramethylammonium hydroxide aqueous solution, the unexposed part was removed, and the pattern after image development was post-baked at 220 degreeC finally, and the bump for liquid crystal orientation control was formed. The film thickness of the bump formed by the photosensitive resin composition of Example 1, 2 and the comparative examples 1, 2 was 1.5 micrometers.

The bump formed using the photosensitive resin composition of Example 1 had a profile angle of 25 degrees, and the bump formed using the photosensitive resin composition of Example 2 had a profile angle of 20 degrees, and black bumps of good shape were formed. OD value was measured using "Gretag Macbeth D-200-2" (brand name: Macbeth company make).

Acid OD value Profile angle (°) Example 1 112 0.65 25 Example 2 112 1.25 20 Comparative Example 1 37 0.6 60 Comparative Example 2 161 1.15 5

According to the photosensitive resin composition of the present invention, by setting the acid value of the photopolymerizable compound contained in the photosensitive resin composition within a specific range, a good pattern can be formed in the alkali development after exposure even in the photosensitive resin composition to which the pigment is added.

Claims (4)

A photosensitive resin composition, which is installed in a liquid crystal cell of a multi-division vertical alignment method, forms bumps for controlling the alignment of liquid crystals. The said photosensitive resin composition contains a photopolymerizable compound (A), a photoinitiator (B), and a pigment (C), The acid value of the photopolymerizable compound (A) is KOH 40 mg / g or more and 160 mg / g or less, The said pigment is the photosensitive resin composition which is 10 mass% or more and 60 mass% or less with respect to the total solid content other than a solvent. The method of claim 1, The photosensitive resin composition whose profile angle of the formed bump is 10 degrees or more and 55 degrees or less. A liquid crystal alignment control bump formed by the photosensitive resin composition according to claim 1. The method of claim 3, wherein Bump for liquid crystal orientation control whose film thickness is 1.0 micrometer or more and 2.0 micrometers or less.