KR20070121543A - Photosensitive resin composition, bump for controlling liquid crystal alignment using the same and method of forming bump for controlling liquid crystal alignment - Google Patents

Abstract

A photosensitive resin composition is provided to disperse a pigment therein effectively and to prevent the formation of residues on an electrode after alkali development by using a pigment dispersant having a polyester bond. A photosensitive resin composition is placed within a liquid crystal cell of a plurally divided vertical alignment mode and forms a bump for controlling alignment of liquid crystals on an electrode. The composition comprises (A) a photopolymerizable compound, (B) a photopolymerization initiator, (C) a pigment, and (D) a pigment dispersant having a polyester bond. A method for forming the bump includes the steps of: applying the photosensitive resin composition onto an electrode-formed substrate to form a photosensitive resin layer; exposing the photosensitive resin layer to a light selectively; and alkali-developing the photosensitive resin layer to form a bump on the photosensitive resin layer.

Description

PHOTOSENSITIVE RESIN COMPOSITION, BUMP FOR CONTROLLING LIQUID CRYSTAL ALIGNMENT USING THE SAME AND METHOD OF FORMING BUMP FOR CONTROLLING LIQUID CRYSTAL ALIGNMENT}

1 is a surface SEM photograph on an ITO film after development when the photosensitive composition of Example 1 is used.

2 is a surface SEM photograph on the ITO film after development in the case of using the photosensitive composition of Example 2. FIG.

3 is a SEM image of the surface on the ITO film after development when the photosensitive composition of Comparative Example 1 is used.

4 is a surface SEM photograph on the ITO film after development when the photosensitive composition of Comparative Example 2 is used.

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

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 sandwiched between the structure and 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.

However, the projections, which are domain regulating means (liquid crystal aligning agents) described in Japanese Patent Laid-Open No. 2004-252480, 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") using a photosensitive resin composition to which a pigment is added and to absorb light. However, when the bump for liquid crystal orientation control was formed using the photosensitive resin composition which added this pigment, the problem which the residue generate | occur | produced on the electrode formed in the board | substrate after image development generate | occur | produced.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, it focused on the dispersing agent which disperse | distributes the pigment contained in the photosensitive resin composition, and studied in detail. As a result, it discovered that the said subject could be solved by using the dispersing agent which has a polyester bond, and came to complete this 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 liquid crystal alignment on an electrode, wherein the pigment (C) has a pigment having a polyester bond. It is a photosensitive resin composition containing a dispersing agent (D).

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

In addition, according to the third aspect of the present invention, the photosensitive resin composition is coated on a substrate on which an electrode is formed to form a photosensitive resin layer, and after the photosensitive resin layer is selectively exposed, alkali development is performed to form bumps on the photosensitive resin layer. A bump forming method for liquid crystal alignment control.

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 which concerns on this invention contains the pigment (C) and the pigment dispersant (D) which has a polyester bond.

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. Among the pigments, organic pigments are preferably used from the viewpoint of lowering the dielectric constant of the formed bumps.

(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 the 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.

(Content of pigment)

It is preferable that they are 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.

Moreover, 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.

[Pigment Dispersant (D)]

The photosensitive resin composition according to the present invention uses a dispersant having a polyester bond as a pigment dispersant for dispersing the pigment in the photosensitive resin composition. Specifically as a dispersing agent which has the said polyester bond, the Sparse 24000, 37500, 39000 (made by Avecia) is mentioned. By using the dispersing agent which has a polyester bond, it can suppress that a residue generate | occur | produces on an electrode (especially on ITO membrane) after alkali image development.

The photosensitive resin composition of the present invention may be either a positive photosensitive composition or a negative photosensitive composition.

<< positive photosensitive composition >>

When the photosensitive resin composition of this invention is a positive photosensitive resin composition, alkali-soluble resin and a photosensitive agent are included in addition to the said pigment (C) and a pigment dispersant (D).

As said alkali-soluble resin, a novolak resin is mentioned, for example.

As said novolak resin, For example, formaldehyde and mixed aldehyde of formaldehyde and salicylaldehyde are added to phenols, such as m-cresol, p-cresol, xylenol, and trimethylphenol, The novolak resin etc. which are manufactured and manufactured by a conventional method under an acidic catalyst are mentioned.

As said photosensitizer, the quinonediazido group containing compound is mentioned, for example. Examples of the quinone diazide group-containing compound include naphthoquinone-1,2-diazide-4-sulfonyl halide or naphthoquinone-1,2-diazide-5-sulfonyl halide, and 2,3 Polyhydroxybenzophenones such as, 4-trihydroxybenzophenone, and 2,3,4,4'-tetrahydroxybenzophenone or bis (4-hydroxy-3,5-dimethylphenyl) -2 -Hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,3,5-trimethylphenyl) -2-hydroxyphenyl Methane, bis (4-hydroxy-2,3,5-trimethylphenyl) -3-hydroxyphenylmethane, bis (4-hydroxy-2,3,5-trimethylphenyl) -4-hydroxyphenylmethane, Bis (4-hydroxy-2-methyl-5-cyclohexylphenyl) -3,4-hydroxyphenylmethane, bis (4-hydroxy-2-methyl-5-cyclohexylphenyl) -4-hydroxyphenyl Trisphenols such as methane and 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene And condensation reaction in organic solvents such as dioxane and γ-butyloacton in the presence of amine catalysts such as butyl amine and triethanol amine, and complete esterification or partial esterification. .

<< negative photosensitive composition >>

When the photosensitive resin composition of this invention is a negative photosensitive resin composition, in addition to the said pigment, a photopolymerizable compound (A) and a photoinitiator (B) are contained.

<< photopolymerizable compound (A) >>

As a photopolymerizable compound, the compound which has an ethylenically unsaturated double bond is preferable.

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. Since these compounds introduce | transduce acryloyl group or a methacryloyl group, the crosslinking efficiency in a coating film becomes high, and this coating film becomes excellent in light resistance and chemical resistance.

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 of the coating film can be improved and the pattern formation can be facilitated.

In the above, as the photopolymerizable compound, the molecule itself can be polymerized. In the present invention, a mixture of the polymer binder and the photopolymerizable monomer is also included in the photopolymerizable compound.

As a polymeric binder, since it is easy to develop, it is preferable that it is a binder which can develop alkali.

Specifically, as the polymer binder, 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, phenoxy acrylate , Copolymers with phenoxy methacrylate, isobornyl acrylate, isobornyl methacrylate, glycidyl methacrylate, styrene, acrylamide, and acrylonitrile, and phenol novolac type epoxy acrylate polymer , Phenol novolac type epoxy methacrylate polymer, cresol novolac type epoxy acrylate polymer, cresol novolac type epoxy Resin, such as a cit methacrylate polymer, a bisphenol-A epoxy acrylate polymer, and a bisphenol S-type epoxy acrylate polymer, is mentioned. 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 using 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.

<< photoinitiator (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-chlorothioxanthene, 2 , 4-diethyl thioxanthene, 2-methylthioxanthene, 2-isopropylthioxanthene, 2-ethylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-diphenylanthra Quinone, azobisisobutyronitrile, benzoyl peroxide, cumene peroxide, 2-mercaptobenzoimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2- (o-chlorophenyl)- 4,5-di (m-methoxyphenyl) -imidazolyl dimer, benzophenone, 2-chlorobenzophenone, p, p'-bisdimethylaminobenzophenone, 4,4'-bisdiethylaminobenzophenone , 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-acdidi Yl) heptane, 1,3-bis- (9-acridinyl) propane, p-methoxytriazine, 2,4,6-tris (trichloromethyl) -s-triazine, 2-methyl-4, 6-bis (Triclaw) 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.

[Other Ingredients]

In the photosensitive resin composition which concerns on this invention, an additive can be mix | blended as needed. Specific examples include a sensitizer, a curing accelerator, a photocrosslinker, a photosensitizer, a dispersant, a dispersant, a filler, an adhesion promoter, an antioxidant, an ultraviolet absorber, an anticoagulant, a thermal polymerization inhibitor, an antifoaming agent, and a surfactant. have.

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-hydroxypropionic acid; 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- The methoxybutyl acetate can be preferably used because it exhibits excellent solubility with respect to the photopolymerizable compound and the photopolymerization initiator and can improve the dispersibility of insoluble components such as pigments, and propylene glycol monomethyl ether acetate, and Particular preference is given to using 3-methoxybutylacetate. 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.

In addition, when forming bumps for liquid crystal alignment control using the photosensitive resin composition according to the present invention, the photosensitive resin composition of the present invention is coated and dried on a substrate on which an electrode film such as an ITO film is formed, as described later, to form a film. In addition to the said component, the photosensitive resin composition of this invention may contain a polymeric binder as a binder. The binder may be appropriately selected and used depending on the purpose of improving compatibility, film formation, developability, and adhesion.

<Method of forming bump for liquid crystal alignment control>

In the method for forming the liquid crystal alignment control bump of the present invention, first, a contact transfer type coating device such as roll coating, reverse coating, and bar coating, spinner (rotary coating device), and curtain flow coating are applied to the photosensitive resin composition according to the present invention on a substrate. Coating is carried out using a non-contact type coating apparatus such as. 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. Further, electrodes such as an ITO film are formed on the substrate by sputtering or the like.

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 ultraviolet rays and excimer ray low light are irradiated through a negative or positive mask to partially expose the 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. Examples of the developer include organic solvents such as monoethanolamine, diethanolamine, and triethanolamine, and aqueous solutions such as sodium hydroxide, potassium hydroxide, sodium carbonate, ammonia, and quaternary ammonium salts. Among these developers, tetramethyl hydroxide is particularly preferred. Ammonium is preferably used. By using tetramethylammonium hydroxide, a favorable pattern can be formed.

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 it reacted and obtained resin. The mass average molecular weight of obtained resin was 3000.

(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 having a polyester bond (product name: Solspas 24000, manufactured by Avecia) are dispersed in 3-methoxybutyl acetate to give a pigment dispersion having a solid content of 15% by mass. A was prepared.

Subsequently, 100 parts by mass of a novolak resin [metacresol: paracresol = 4: 6] (product name: M1, Sumitomo Becrite Co., Ltd.), 25 parts by mass of a sensitizer (product name: PA, Honshu Kagaku Kogyo Co., Ltd.) Product name: MB25, manufactured by Daito Chemical Co., Ltd.), and 50 parts by mass of the above-mentioned pigment dispersion A are mixed, dissolved in propylene glycol monomethyl ether acetate (PGMEA), and adjusted so that the solid content concentration is 20% by mass, thereby providing a photosensitive resin. The composition was prepared.

(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-1 as a polymerization initiator 10 parts by mass of (on product name: Monocure 369, manufactured by Chiba Specialty Chemicals Co., Ltd.) and 20 parts by mass of the above-mentioned pigment dispersion A were dissolved in propylene glycol monomethyl ether acetate (PGMEA) to obtain a solid concentration of 20% by mass. It adjusted and the photosensitive resin composition was produced.

(Example 3)

22 parts by mass of carbon black and 5 parts by mass of a polymer dispersant having a polyester bond (product name: Solpas 24000, manufactured by Avecia) were dispersed in 73 parts by mass of 3-methoxybutyl acetate to obtain a carbon black dispersion.

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 Chemicals Co., Ltd.) and 20 parts by mass of the carbon black dispersion are mixed, dissolved in propylene glycol monomethyl ether acetate (PGMEA) so that the solid concentration is 20% by mass. It adjusted and the photosensitive resin composition was produced.

(Comparative Example 1)

A photosensitive resin composition was prepared in the same manner as in Example 1, using a polyurethane-based dispersant (product name: BYK-164, manufactured by Japan Chemical Co., Ltd.) as a dispersant.

(Comparative Example 2)

A photosensitive resin composition was prepared in the same manner as in Example 2, using a polyurethane-based dispersant (product name: BYK-170, manufactured by VK Chemie Co., Ltd.).

[Method of forming bump for liquid crystal alignment control]

A photosensitive resin composition was applied onto a glass substrate on which an indium tin oxide (ITO) film was formed, and dried at 90 ° C. for 2 minutes to form a photosensitive resin layer. Subsequently, the positive masks were applied to Example 1 and Comparative Example 1, and the ultraviolet rays having an energy dose of 50 mJ / cm ² were selectively irradiated partially through the negative masks of Examples 2 and 2, respectively. . Next, it developed using tetramethylammonium hydroxide aqueous solution and the post-development pattern was post-baked at 220 degreeC, and the bump for liquid crystal orientation control was formed.

(evaluation)

SEM photographs confirmed the presence or absence of residue on the surface of the ITO film after development when bumps were formed using the photosensitive resin compositions of Examples 1 to 3 and Comparative Examples 1 and 2. Moreover, the OD value per film thickness of 1 micrometer was evaluated about the formed bump. OD value was measured using "Gretag Macbeth D-200-2" (brand name: Macbeth company make).

Presence of residue OD value SEM photo Example 1 none 0.60 1 Example 2 none 0.65 2 Example 3 none 1.25 - Comparative Example 1 has exist 0.60 3 Comparative Example 2 has exist 0.65 4

As can be seen with reference to FIGS. 1 and 2, no residues were generated in the photosensitive resin compositions of Examples 1 and 2 using a dispersant having a polyester bond. On the other hand, as can be seen with reference to FIGS. 3 and 4, residues occurred in the photosensitive resin compositions of Comparative Examples 1 and 2 using a dispersant having a polyurethane bond having no polyester bond.

From the above results, it was shown that the photosensitive resin composition of the present invention can prevent the occurrence of residues on the developed ITO film.

According to the photosensitive resin composition of the present invention, as the pigment dispersant (D) included in the photosensitive resin composition, a pigment is sufficiently sprayed into the photosensitive resin composition by using a dispersant having a polyester bond, and the residue is left on the electrode after alkali development. Can be suppressed from occurring.

Claims (7)

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 on an electrode. Photosensitive resin composition containing the pigment (C) and the pigment dispersant (D) which has a polyester bond. The method of claim 1, Photosensitive resin composition wherein the pigment (C) is an organic pigment. The method of claim 1, Photosensitive resin composition containing a photopolymerizable compound (A) and a photoinitiator (B). A liquid crystal alignment control bump formed by the photosensitive resin composition according to any one of claims 1 to 3. The method of claim 4, wherein Bump for liquid crystal orientation control whose OD value in a film thickness of 1 micrometer is 0.6 or more. The photosensitive resin composition as described in any one of Claims 1-3 is apply | coated on the board | substrate with which an electrode was formed, the photosensitive resin layer is formed, after selectively exposing the photosensitive resin layer, alkali development is carried out and bumps are applied to the photosensitive resin layer. A bump forming method for liquid crystal alignment control to be formed. The method of claim 6, The bump formation method for liquid crystal orientation control of which the developing solution used for the said alkali image development is tetramethylammonium hydroxide.

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