JP2015011095A - Photosensitive resin composition for forming photospacer and color filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive resin composition for a photospacer that allows formation while enabling both smaller diameter of a PS concurrent with higher definition of a color filter 1 and higher sensitivity, and a color filter 1 using the photospacer.SOLUTION: A photosensitive resin composition for forming a photospacer 5 includes photoinitiator, binder polymer, photosensitive monomer, surfactant and solvent. The photosensitive resin composition for forming a photospacer 5 is laminated on a light shielding layer 3 on a transparent substrate 2, as a photospacer 5 included in a color filter 5 for a liquid crystal display device. The photoinitiator includes a fluorene-based oxime ester compound expressed by chemical formula 1.

Description

  The present invention relates to a photosensitive resin composition for forming a photospacer used in a color liquid crystal display device and the like, and a color filter formed using the same.

  Liquid crystal display devices are widely used in various display devices because they are small, thin, lightweight, and have low power consumption. As an example of such a liquid crystal display device, the color filter has a plurality of colors (usually red (R), green (G), and blue (B) 3 on a transparent substrate provided with a light shielding layer (black matrix). A colored layer composed of a primary color) is disposed, and a transparent conductive film (transparent electrode) serving as an electrode of a liquid crystal display device is laminated thereon, and is provided between the color filter substrate and the thin film transistor (TFT) substrate. A spacer for maintaining a predetermined thickness (cell gap) is provided.

  If this cell gap is not accurately maintained, the thickness of the liquid crystal layer will be different and coloring due to the difference in the optical rotation characteristics of the liquid crystal or partial color unevenness will be adversely affected. For example, a method of forming a columnar resin spacer at a desired position, for example, on a lattice-patterned BM at the boundary between pixels, has become a mainstream by photolithography. Hereinafter, such a spacer is referred to as a photo spacer (PS) (Patent Documents 1 and 2).

  In recent years, liquid crystal display devices have been increased in size and cost, and accordingly, improvement in productivity has been demanded, and the photosensitive resin composition used for forming various members constituting the color filter has also been increased. There is a need for more efficient production processes such as increased sensitivity.

  More recently, the resolution of liquid crystal display devices has increased, and the pixel pitch has become narrower. In the past, the width of one pixel was around 100 μm, but for example, the VGA type for cellular phones has become narrower to about 25 μm. The line width of the BM formed on the color filter substrate is 6 μm or less than the conventional line width of 20 to 30 μm. Along with such changes, the size of the PS also decreases. For example, in the case of PS, a conventional pyramid with an upper base of 20 μm × 20 μm or more is reduced to an upper base of 10 μm × 10 μm or less. ing.

  For such a PS having a reduced diameter, the development resistance tends to be lower than that of a conventional PS, and pattern peeling tends to occur. Furthermore, when the exposure amount is kept low for higher sensitivity, the film is more easily peeled off. In recent years, carbazole-based oxime ester compounds have been widely used as high-sensitivity photopolymerization initiators, but there has been no discussion about the development of such small-diameter PS (Patent Document 3).

  Furthermore, proposals using ketoxime ester-based photopolymerization initiators have been made, but only a resolution check with a fine line pattern has been made, and specific mention has been made of the formation of small-diameter PS with a narrower peeling margin. In fact, in order to form a small-diameter PS, a photosensitive resin composition capable of forming PS with higher sensitivity and higher adhesion is required (Patent Document 4).

JP 2001-91954 A JP 2001-92128 A Japanese Patent No. 5151433 JP 2011-105713 A

  The present invention has been made in view of the problems as described above, and is a photosensitive resin composition for a photospacer that can be formed with both a reduction in the diameter of PS and an increase in sensitivity associated with higher definition of a color filter. Another object of the present invention is to provide a color filter using the same.

As means for solving the above-mentioned problems, the invention described in claim 1 is directed to a photosensitive resin composition for forming a photospacer comprising a photopolymerization initiator, a binder polymer, a photosensitive monomer, a surfactant, and a solvent. Because
The photo-spacer-forming photosensitive resin composition is laminated on a light-shielding layer on a transparent substrate as a photo-spacer constituting a color filter for a liquid crystal display device,
The photopolymerization initiator contains a fluorene-based oxime ester compound represented by the chemical formula 1, and is a photosensitive resin composition for forming a photospacer.

［化式１において、Ｘ^１は、Ｒ^１１、ＯＲ^１１、ＣＯＲ^１１、ＳＲ^１１、ＣＯＮＲ^１２Ｒ^１３又はＣＮを表し、Ｘ^２・Ｘ^３・Ｘ^７は置換基を有していてもよい炭素原子数１〜２０のアルキル基、置換基を有していてもよい炭素原子数６〜３０のアリール基、置換基を有していてもよい炭素原子数７〜３０のアリールアルキル基又は置換基を有していてもよい炭素原子数２〜２０の複素環基を表し、Ｘ^４は、Ｒ^１１、ＯＲ^１１、ＣＯＲ^１１、ＳＲ^１１、ＣＯＮＲ^１２Ｒ^１３、ＮＯ_２、ＳＯ_４Ｈ、ＣＮ、ハロゲン原子又は水酸基を表し、Ｘ^５及びＸ^６は、それぞれ独立に、Ｒ^１１、ＯＲ^１１、ＳＲ^１１、ＣＯＲ^１１、ＣＯＮＲ^１２Ｒ^１３、ＮＲ^１２ＣＯＲ^１１、ＯＣＯＲ^１１、ＣＯＯＲ^１１、ＳＣＯＲ^１１、ＣＯＳＲ^１１、ＣＯＳＲ^１１、ＣＳＯＲ^１１、ＣＮ、ハロゲン原子又は水酸基を表す。Ｒ^１１、Ｒ^１２及びＲ^１３は、それぞれ独立に、水素原子、置換基を有していてもよい炭素原子数１〜２０のアルキル基、置換基を有していてもよい炭素原子数６〜３０のアリール基、置換基を有していてもよい炭素原子数７〜３０のアリールアルキル基又は置換基を有していてもよい炭素原子数２〜２０の複素環基を表す。ａ及びｂはそれぞれ独立に、０〜３である。]
また、請求項２に記載の発明は、前記フルオレン系オキシムエステル化合物が、化式２で表されることを特徴とする請求項１に記載のフォトスペーサー形成用感光性樹脂組成物である。

[In the chemical formula 1, X ¹ represents R ¹¹ , OR ¹¹ , COR ¹¹ , SR ¹¹ , CONR ¹² R ¹³ or CN, and X ² · X ³ · X ⁷ may have a substituent. An alkyl group having 1 to 20 atoms, an aryl group having 6 to 30 carbon atoms which may have a substituent, an arylalkyl group having 7 to 30 carbon atoms which may have a substituent or a substituent; And X ⁴ represents R ¹¹ , OR ¹¹ , COR ¹¹ , SR ¹¹ , CONR ¹² R ¹³ , NO ₂ , SO ₄ H, CN, Represents a halogen atom or a hydroxyl group, and X ⁵ and X ⁶ are each independently R ¹¹ , OR ¹¹ , SR ¹¹ , COR ¹¹ , CONR ¹² R ¹³ , NR ¹² COR ¹¹ , OCOR ¹¹ , COOR ¹¹ , SCOR ¹¹ , COSR ¹¹ , COSR ¹¹ , CSOR ¹¹ , CN, a halogen atom or a hydroxyl group. R ¹¹ , R ¹² and R ¹³ are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 20 carbon atoms, or an optionally substituted carbon atom having 6 to 6 carbon atoms. It represents a 30 aryl group, an optionally substituted arylalkyl group having 7 to 30 carbon atoms, or an optionally substituted heterocyclic group having 2 to 20 carbon atoms. a and b are each independently 0-3. ]
The invention described in claim 2 is the photosensitive resin composition for forming a photospacer according to claim 1, wherein the fluorene-based oxime ester compound is represented by the formula 2.

また、請求項３に記載の発明は、前記フルオレン系オキシムエステル化合物が、化式３で表されることを特徴とする請求項１に記載のフォトスペーサー形成用感光性樹脂組成物である。

The invention described in claim 3 is the photosensitive resin composition for forming a photospacer according to claim 1, wherein the fluorene-based oxime ester compound is represented by Formula 3.

また、請求項４に記載の発明は、請求項１〜３のいずれか一項に記載のフォトスペーサー形成用感光性樹脂組成物を用いたフォトスペーサーを具備したことを特徴とするカラーフィルタである。

The invention according to claim 4 is a color filter comprising a photo spacer using the photosensitive resin composition for forming a photo spacer according to any one of claims 1 to 3. .

According to the photosensitive resin composition of the present invention, since a specific oxime ester photopolymerization initiator is used, a photospacer excellent in development resistance and resolution can be formed even at a low exposure amount. Can do. Therefore, a high-definition color filter or liquid crystal display device can be efficiently obtained by using the photosensitive resin composition of the present invention.

It is the conceptual diagram which showed an example of embodiment of the color filter 1 provided with the photo spacer 5 of this invention.

  Hereinafter, the photosensitive resin composition of this invention and the color filter 1 using the same are demonstrated in detail based on one Embodiment below.

  The photosensitive resin composition according to the present invention is a photosensitive resin composition comprising at least a binder polymer, a photosensitive monomer, and a photopolymerization initiator, and is a fluorene-based oxime represented by Formula 1 as a photopolymerization initiator. It contains an ester compound.

In the chemical formula 1, X ¹ represents R ¹¹ , OR ¹¹ , COR ¹¹ , SR ¹¹ , CONR ¹² R ¹³ or CN, and X ² , X ^3, and X ⁷ may have a substituent. An alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms which may have a substituent, an arylalkyl group having 7 to 30 carbon atoms which may have a substituent or a substituent; Represents an optionally substituted heterocyclic group having 2 to 20 carbon atoms, and X ⁴ represents R ¹¹ , OR ¹¹ , COR ¹¹ , SR ¹¹ , CONR ¹² R ¹³ , NO ₂ , SO ₄ H, CN, halogen represents an atom or a hydroxyl group, ^{X 5} and ^{X 6, independently, R 11, oR 11, SR} 11, COR 11, CONR 12 R 13, NR 12 COR 11, OCOR 11, COOR 11, SCOR 11 ^{COSR 11, COSR 11, CSOR 11} , CN, a halogen atom or a hydroxyl group. R ¹¹ , R ¹² and R ¹³ are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 20 carbon atoms, or an optionally substituted carbon atom having 6 to 6 carbon atoms. It represents a 30 aryl group, an optionally substituted arylalkyl group having 7 to 30 carbon atoms, or an optionally substituted heterocyclic group having 2 to 20 carbon atoms. a and b are each independently 0-3.

X ¹ is particularly preferably a methyl group, an ethyl group, an n-propyl group, an isopropyl group, n, from the viewpoint of ease of synthesis, sensitivity, solubility, and storage stability when contained in a black photosensitive resin composition. -Butyl group, isobutyl group, t-butyl group, n-amyl group, isoamyl group, t-amyl group, n-hexyl group, 2-ethylhexyl group and other alkyl groups having 10 or less carbon atoms, cyclopentyl group, cyclohexyl group, etc. An arylalkyl group having an aromatic ring such as a cyclic alkyl group, an aryl group, or a methylaryl group, which may have a side chain of 10 or less carbon atoms, a methoxymethyl group, an ethoxymethyl group, an ethoxyethyl group, 2- ( 1-methoxypropyl) group, 2- (1-ethoxypropyl) group and the like are alkyl groups having 10 or less carbon atoms and one ether bond in the methylene chain.

X ² · X ³ · X ⁷ is particularly preferably a methyl group, an ethyl group, or n-propyl, from the viewpoint of ease of synthesis, sensitivity, solubility, and storage stability when contained in a black photosensitive resin composition. Group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, n-amyl group, isoamyl group, t-amyl group, n-hexyl group and other alkyl groups having 6 or less carbon atoms, cyclopentyl group, cyclohexyl group Or a cyclic alkyl group having 6 or less carbon atoms, such as a methoxymethyl group, an ethoxymethyl group, an ethoxyethyl group, a 2- (1-methoxypropyl) group, or a 2- (1-ethoxypropyl) group. An alkyl group having one ether bond in the methylene chain.

X ⁴ is particularly preferably hydrogen, or a methyl group, an ethyl group, an n-propyl group, or an isopropyl group from the viewpoint of ease of synthesis, sensitivity, solubility, and storage stability when contained in a photosensitive coloring composition. , N-butyl group, isobutyl group, t-butyl group, n-amyl group, isoamyl group, t-amyl group, n-hexyl group and other alkyl groups having 6 or less carbon atoms, cyclopentyl group, cyclohexyl group, etc. 6 or less cyclic alkyl group, methoxymethyl group, ethoxymethyl group, ethoxyethyl group, 2- (1-methoxypropyl) group, 2- (1-ethoxypropyl) group and the like having 6 or less carbon atoms in the methylene chain An alkyl group having one ether bond, a nitro group, a sulfone group, a cyano group, a halogen atom, a hydroxyl group and the like.

X ⁵ and X ⁶ are particularly preferably a methyl group, an ethyl group, an n-propyl group, or an isopropyl group from the viewpoint of ease of synthesis, sensitivity, solubility, and storage stability when contained in a photosensitive coloring composition. , N-butyl group, isobutyl group, t-butyl group, n-amyl group, isoamyl group, t-amyl group, n-hexyl group and other alkyl groups having 6 or less carbon atoms, cyclopentyl group, cyclohexyl group, etc. 6 or less cyclic alkyl group, methoxymethyl group, ethoxymethyl group, ethoxyethyl group, 2- (1-methoxypropyl) group, 2- (1-ethoxypropyl) group and the like having 6 or less carbon atoms in the methylene chain An alkyl group having one ether bond, a cyano group, a halogen atom, a hydroxyl group and the like.

  As such a photopolymerization initiator, compounds of the chemical formulas 4 to 9 can be specified.

化式１で表される光重合開始剤の合成法は、特に制限は無いが以下の方法により合成できる。

The method for synthesizing the photopolymerization initiator represented by Formula 1 is not particularly limited, but can be synthesized by the following method.

  As shown in Chemical Formula 10, synthesis of acyl body: Fluorene compound 1 and acid chloride 2 are reacted in the presence of aluminum chloride to obtain acyl body 3 as a target product.

オキシムエステル化合物の合成：化式１１に示す様に、アシル体３と、塩酸ヒドロキシルアミンと、ジメチルホルムアミドを仕込み、加熱攪拌し、オキシム化合物４を得る。オキシム化合物４と酸無水物５を加熱攪拌し、反応終了後、アルカリで中和し、オキシムエステル化合物６が得られる。

Synthesis of Oxime Ester Compound: As shown in Chemical Formula 11, acyl body 3, hydroxylamine hydrochloride and dimethylformamide are charged and heated and stirred to obtain oxime compound 4. The oxime compound 4 and the acid anhydride 5 are heated and stirred. After completion of the reaction, the oxime compound 4 is neutralized with an alkali to obtain the oxime ester compound 6.

オキシムエステル化合物の合成：化式１２に示す様にオキシムエステル化合物６と酸クロライド７を塩化アルミニウムの存在下で反応し、目的物であるオキシムエステル化合物８を得る。

Synthesis of oxime ester compound: As shown in chemical formula 12, oxime ester compound 6 and acid chloride 7 are reacted in the presence of aluminum chloride to obtain oxime ester compound 8 which is the target product.

オキシムエステル化合物の合成：化式１３に示す様にオキシムエステル化合物６を硫酸
酸性条件下で硝酸と反応し、目的物であるオキシムエステル化合物９を得る。

Synthesis of oxime ester compound: As shown in chemical formula 13, oxime ester compound 6 is reacted with nitric acid under sulfuric acid acidic condition to obtain oxime ester compound 9 which is the target product.

化式１で表される光重合開始剤は、近接露光装置の光源として広く用いられている高圧水銀灯とのマッチングに優れ、主要な輝線であるｉ線（３６５ｎｍ）、ｈ線（４０５ｎｍ）の光を効率良く吸収するため、感光性樹脂組成物を高感度化することができる。このため、小径化のために露光量を低く抑えた場合にもパターンを十分に硬化することができ、パターン剥がれの発生を防止することが可能である。また、少量で感光性樹脂組成物の感度を生産性に支障が生じないレベルに調整できる。

The photopolymerization initiator represented by Formula 1 is excellent in matching with a high-pressure mercury lamp widely used as a light source of a proximity exposure apparatus, and emits light of i-line (365 nm) and h-line (405 nm) which are main emission lines. Is efficiently absorbed, the sensitivity of the photosensitive resin composition can be increased. For this reason, the pattern can be sufficiently cured even when the exposure amount is kept low to reduce the diameter, and pattern peeling can be prevented. In addition, the sensitivity of the photosensitive resin composition can be adjusted to a level that does not hinder productivity in a small amount.

  The content of the photopolymerization initiator represented by Formula 1 is preferably 0.5 to 5% by weight, more preferably 1 to 3% by weight in the solid content of the photosensitive resin composition. is there. When the content of the photopolymerization initiator is within this range, it is possible to form a photo spacer having a line width of 10 μm or less with an exposure amount suitable for production. When the content of the photopolymerization initiator is 0.5% by weight or less, the sensitivity of the photosensitive resin composition is insufficient. On the other hand, when the content of the photopolymerization initiator is 5% by weight or more, the pattern line width becomes too thick.

  In addition to the photopolymerization initiator represented by Formula 1, another photopolymerization initiator can be used in combination with the photosensitive resin composition of the present invention. Other photopolymerization initiators include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl)- Acetophenone compounds such as butan-1-one, benzoin compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl dimethyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenyl Benzophenone compounds such as nzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4′-methyldiphenyl sulfide, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, thioxanthone, 2- Thioxanthone compounds such as chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, 2,4-diethylthioxanthone, 2,4,6-trichloro-s-triazine, 2-phenyl-4,6- Bis (trichloromethyl) -s-triazine, 2- (p-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -S-triazine 2-piperonyl-4,6-bis (trichloromethyl) -s-triazine, 2,4-bis (trichloromethyl) -6-styryl-s-triazine, 2- (naphth-1-yl) -4,6- Bis (trichloromethyl) -s-triazine, 2- (4-methoxy-naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6 -Triazines such as triazine, 2,4-trichloromethyl (4'-methoxystyryl) -6-triazine, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenyl Phosphine compounds such as phosphine oxide, 9,10-phenanthrenequinone, camphorquinone, ethyl anthracite Non-quinone compounds, borate compounds, carbazole compounds, imidazole compounds, titanocene compounds, and the like are used. These photopolymerization initiators can be used alone or in combination of two or more at any ratio as required.

As the binder polymer of the photosensitive resin composition of the present invention, acrylic acrylate, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, and other alkyl acrylates or alkyl methacrylates, cyclic cyclohexyl acrylate or methacrylate A resin having a molecular weight of about 5,000 to 100,000, which is synthesized using about 3 to 5 types of monomers from hydroxyethyl acrylate or methacrylate, styrene, or the like can be preferably used.

  In addition, as a resin in which an unsaturated double bond is added to a part of an acrylic resin, a compound such as the above acrylic resin, isocyanate ethyl acrylate having at least one vinyl group and an isocyanate group, or methacryloyl isocyanate is reacted. The photosensitive copolymer having an acid value of 50 to 150 can be preferably used from the viewpoints of heat resistance, developability and the like. Furthermore, bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac type epoxy resin, polycarboxylic acid glycidyl ester, polyol polyglycidyl ester, aliphatic or cycloaliphatic epoxy resin, amine epoxy resin, triphenolmethane type epoxy resin, Ordinary photopolymerizable resins such as epoxy (meth) acrylate obtained by reacting an epoxy resin such as a dihydroxybenzene type epoxy resin and (meth) acrylic acid, or a cardo resin can also be used.

  As the photosensitive monomer of the photosensitive resin composition of the present invention, for example, ethylene glycol (meth) acrylate, diethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polyethylene glycol di (Meth) acrylate, polypropylene glycol di (meth) acrylate, hexane di (meth) acrylate, neopentyl glycol di (meth) acrylate, glycerol di (meth) acrylate, glycerol tri (meth) acrylate, glycerol tetra (meth) acrylate, tetra Trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipenta Risuri penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate and the like, these components are used alone or as a mixture. Various modified (meth) acrylates, urethane (meth) acrylates, and the like can also be used.

  Solvents include methanol, ethanol, ethyl cellosolve, ethyl cellosolve acetate, diglyme, cyclohexanone, ethylbenzene, xylene, isoamyl acetate, n amyl acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, propylene glycol mono Ethyl ether acetate, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, triethylene glycol, Liethylene glycol monomethyl ether, triethylene glycol monomethyl ether acetate, triethylene glycol monoethyl ether, triethylene glycol monoethyl ether acetate, liquid polyethylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether , Dipropylene glycol monoethyl ether acetate, lactic acid ester, ethyl ethoxypropionate and the like.

  Moreover, you may contain an additive further in the photosensitive coloring composition of this invention as needed. Specific examples of such additives include surfactants, dissolution accelerators, adhesion promoters, antioxidants, ultraviolet absorbers, polymerization inhibitors, and sensitizers.

Hereinafter, a method for manufacturing a color filter 1 for a liquid crystal display device and a color filter 1 according to the present invention will be described with reference to FIG. The color filter 1 includes a transparent substrate 2, a light shielding layer 3 formed on the substrate, and a colored layer 4 composed of red pixels 4R, green pixels 4G, and blue pixels 4B, on which ITO serving as a transparent conductive film is formed. Is formed by sputtering. Thereafter, a photospacer 5 is formed at a predetermined position of the light shielding layer 3 with the photosensitive resin composition of the present invention.

  As the transparent substrate 2 constituting the color filter 1, a substrate having a certain transmittance with respect to visible light is preferable, and a substrate having a transmittance of 80% or more is more preferable. Generally used for liquid crystal display devices, such as plastic substrates such as PET and glass can be mentioned. Generally, non-alkali glass with a low coefficient of thermal expansion and excellent dimensional accuracy at high temperatures is widely used. It has been.

  In addition, the light shielding layer 3 provided on the transparent substrate 2 is provided between pixels of each color or outside the region where the colored layer 4 is formed in order to prevent a decrease in contrast due to light leakage.

  As a method for forming the colored pixels 4 and the light shielding layer 3 on the transparent substrate 2, a pigment dispersion method is mainly used. In the pigment dispersion method, a coating layer of a photosensitive coloring composition in which a color material such as an organic pigment is dispersed is patterned by a known photolithography method, whereby the color filter 1 is divided into a plurality of colored layers 4 (red pixels 4R, green pixels). 4G, blue pixel 4B, etc.). Although the order of coloration of the plurality of colored layers 4 is not limited, for the sake of alignment, colored pixels (red pixel 4R, green pixel 4G, blue pixel are formed by applying the colored layer, exposing, developing, etc. after forming the pattern of the light shielding layer. 4B, etc.) are formed sequentially.

The transparent conductive film is provided on the top of the color filter 1 and is made of a transparent and conductive material that can be formed into a thin film. Usually, an ITO (complex oxide of indium and tin) film is used, and the other is IZO (indium). And a composite oxide of zinc and SnO ₂ (tin dioxide) are selected, and can be formed by a general film forming method such as a sputtering method, a PVD method such as a vacuum evaporation method, or a CVD method.

  The photo spacer 5 determines the gap of the liquid crystal cell when the color filter 1 and the TFT substrate are bonded together, and plays an important role for display quality. The photo spacer 5 of the present invention has a certain height, and its uniformity is required. In addition to the height, the shape, size, density, and the like required for the photospacer 5 are appropriately determined depending on the design of the liquid crystal display device.

  In the color filter 1 according to the present invention, the layer configuration for forming the photo spacer 5 may be changed as appropriate according to the driving method of the liquid crystal display device. For example, in the case of an IPS (lateral electric field) type liquid crystal display device, a transparent protective layer can be formed on a colored pixel, and a photospacer 5 made of the photosensitive resin composition of the present invention can be formed thereon.

<Synthesis of binder polymer solution>
In a 5-neck reaction vessel with an internal volume of 2 liters,
Propylene glycol monomethyl ether acetate (PGMAc) 800 g Butyl methacrylate (BMA) 140 g Methacrylic acid (MAA) 30 g Hydroxyethyl methacrylate (HEMA) 30 g Azobisisobutyronitrile (AIBN) 4 g is added and heated at 80 ° C. for 6 hours while blowing nitrogen. Thus, a transparent soluble resin (A) solution was obtained. After cooling to room temperature, about 2 g of the resin solution was sampled and heated and dried at 180 ° C. for 20 minutes to measure the nonvolatile content. Propylene glycol monomethyl ether so that the nonvolatile content was 20% by mass in the previously synthesized resin solution. Acetate was added to prepare a binder polymer solution.

<Preparation of photosensitive resin composition 1>
Binder polymer solution: 120.2 parts by weight Photosensitive monomer: UD408A (manufactured by Osaka Organic Chemical Industries) 30.0 parts by weight Dipentaerythritol pentaacrylate diisocyanate urethane prepolymer photopolymerization initiator: Formula 2 DFI-020 (Dai-Tokemix) Manufactured) A photosensitive resin composition 1 was prepared by diluting with cyclohexanone so that the solid content in 1.0 part by weight of the photosensitive resin composition was 20% by weight.

<Preparation of coloring material>
The following were used as the coloring agents for coloring the coloring material used for producing the color filter.
Red pigment: C.I. I. Pigment Red 254
Ilgar For Red B-CF (Ciba Specialty Chemicals)
: C.I. I. Pigment Red 177
Chromothal Red A2B (Ciba Specialty Chemicals)
Green pigment: C.I. I. Pigment Green 36
Lionol Green 6YK (Toyo Ink Manufacturing Co., Ltd.)
: C.I. I. Pigment Yellow 150
Funchon First Yellow Y-5688 (manufactured by Bayer)
Blue pigment: C.I. I. Pigment Blue 15
Lionol Blue ES (Toyo Ink Manufacturing Co., Ltd.)
: C.I. I. Pigment Violet 23
Paliogen Violet 5890 (BASF)
Red, green and blue coloring materials were prepared using the above pigments.

<Red coloring material>
A mixture having the following composition was uniformly stirred and mixed, then dispersed in a sand mill for 5 hours using glass beads having a diameter of 1 mm, and then filtered through a 5 μm filter to prepare a red pigment dispersion.
Red pigment: C.I. I. Pigment Red254 18 parts by weight Red pigment: C.I. I. Pigment Red177 2 parts by weight Krill varnish (solid content 20%) 108 parts by weight Thereafter, a mixture having the following composition was stirred and mixed so as to be uniform, and then filtered through a 5 μm filter to obtain a red colored material.
150 parts by weight of the above dispersion NK ester ATMPT (manufactured by Shin-Nakamura Chemical) 13 parts by weight
Trimethylolpropane triacrylate photopolymerization initiator: Irgacure 907 (manufactured by BASF) 3 parts by weight Sensitizer: EAB-F (manufactured by Hodogaya Chemical Co., Ltd.) 1 part by weight Solvent: 253 parts by weight of cyclohexanone.

<Green coloring material>
It produced by the method similar to a red coloring material so that a composition might become the following composition, respectively.
Green pigment: C.I. I. Pigment Green 36 16 parts by weight yellow pigment: C.I. I. Pigment Yellow 150 8 parts by weight Acrylic varnish: (solid content 20%) 102 parts by weight Trimethylolpropane triacrylate: NK ester ATMPT 14 parts by weight
(Shin Nakamura Chemical Co., Ltd.)
Photoinitiator: Irgacure 907 (manufactured by BASF) 4 parts by weight Sensitizer: EAB-F (manufactured by Hodogaya Chemical) 2 parts by weight Solvent: 257 parts by weight of cyclohexanone.

<Blue coloring material>
It produced by the method similar to a red coloring material so that a composition might become the following composition, respectively.
Blue pigment: C.I. I. Pigment Blue 15 50 parts by weight purple pigment: C.I. I. Pigment Violet 23 2 parts by weight Dispersant: Sols Birds 20000 (manufactured by Zeneca) 6 parts by weight Acrylic varnish: (solid content 20%) 200 parts by weight Trimethylolpropane triacrylate: NK ester ATMPT 19 parts by weight
(Shin Nakamura Chemical Co., Ltd.)
Photoinitiator: Irgacure 907 (manufactured by BASF) 4 parts by weight Sensitizer: EAB-F (manufactured by Hodogaya Chemical Co., Ltd.) 2 parts by weight Solvent: 214 parts by weight of cyclohexanone.

<Colored layer formation and transparent conductive film formation>
A colored layer was formed using the obtained coloring material. A photomask having a stripe pattern for colored pixels after a red coloring material is applied to a transparent substrate made of glass on which a light shielding layer is formed by spin coating so as to have a finished film thickness of 2.0 μm and dried under reduced pressure. Was irradiated with 150 mJ / cm ² with a high-pressure mercury lamp. After developing with an alkali developer for 60 seconds, washing with water and drying, a post-baking treatment at 230 ° C. for 20 minutes was performed to form a red colored layer. Subsequently, the same processing was performed for the green coloring material and the blue coloring material, and a color filter having three colored layers of red, green, and blue was formed on the substrate. The alkaline developer has the following composition.
Sodium carbonate 1.5 parts by weight Sodium hydrogen carbonate 0.5 parts by weight Anionic surfactant: Perirex NBL (manufactured by Kao Corporation) 8.0 parts by weight Water 90.0 parts by weight Next, this color filter was oxidized. A transparent electrode film (thickness 1500 mm) made of indium tin (ITO) was formed by a general sputtering method.

<Formation of photo spacer>
The photosensitive resin composition 1 was spin-coated on the transparent conductive film of the above-described color filter so that the final film thickness was 4 μm, pre-baked at 90 ° C. for 1 minute, and a pattern formation mask (hexagonal shape with an opening of 8 μmφ) The pattern was exposed with a high-pressure mercury lamp (30 to 100 mJ / cm ² ). After developing with an alkali developer for 60 seconds, washing with water and drying, a post-baking treatment was performed at 230 ° C. for 40 minutes to form a photo spacer on the non-display portion of the color filter.

  A photospacer was formed in the same manner as in Example 1 except that the photosensitive resin composition for forming the photospacer was changed to the photosensitive resin composition 2 having the following composition.

<Preparation of photosensitive resin composition 2>
Binder polymer: 120.2 parts by weight Photosensitive monomer: UD408A (manufactured by Osaka Organic Chemical Industry) 30.0 parts by weight
Dipentaerythritol pentaacrylate diisocyanate urethane prepolymer initiator: Formula 3 DFI-091 (manufactured by Daitokemix) 1.0 part by weight Dilute with cyclohexanone so that the solid content in the photosensitive resin composition is 20% by weight, Photosensitive resin composition 2 was prepared.

<Comparative Example 1>
A photospacer was formed in the same manner as in Example 1 except that the photosensitive resin composition for forming the photospacer was changed to the photosensitive resin composition 3 having the following composition.

<Preparation of photosensitive resin composition 3>
Binder polymer: 115.7 parts by weight Photopolymerizable monomer: UD408A (manufactured by Osaka Organic Chemical Industry) 28.9 parts by weight
Dipentaerythritol pentaacrylate diisocyanate urethane prepolymer initiator: OXE-01 (manufactured by BASF) 1.9 parts by weight Diluted with cyclohexanone so that the solid content in the photosensitive resin composition is 20% by weight, and photosensitive resin Composition 3 was prepared.
<Comparative example 2>
A photospacer was formed in the same manner as in Example 1 except that the photosensitive resin composition for forming a photospacer was changed to the photosensitive resin composition 4 having the following composition.

<Preparation of photosensitive resin composition 4>
Binder polymer: 120.2 parts by weight Photosensitive monomer: UD408A (manufactured by Osaka Organic Chemical Industry) 30.0 parts by weight
Dipentaerythritol pentaacrylate diisocyanate urethane prepolymer initiator: OXE-02 (manufactured by BASF) 1.0 part by weight Diluted with cyclohexanone so that the solid content in the photosensitive resin composition is 20% by weight, and the photosensitive resin Composition 4 was prepared <Evaluation of photosensitive resin composition>
About the photosensitive resin composition of Examples 1-2 and Comparative Examples 1-2, it evaluated according to the following procedure.

<Sensitivity>
During exposure,
○: × what amount was sufficient 30mJ / cm ^2: 30mJ / cm at ² insufficient, and to those exposed at 100 mJ / cm ^2.

<Resolution>
During exposure development,
◯: The pattern was satisfactorily formed with a PS line width of 10 μm (± 1 μm). X: The PS line width was 10 μm to 2 μm or more.

<Adhesion>
Observe the peeling of the pattern obtained by development visually,
◯: Pattern peeling was not observed at all ×: Pattern peeling was observed

The results are shown in Table 1. In Examples 1 and 2 using the photosensitive resin composition of the present invention, a photospacer having a lower bottom line width of 10 μm or less and having a good appearance can be formed under a low exposure amount condition of an exposure amount of about 30 mJ / cm ² , and a development margin is also achieved. It was good.

On the other hand, in Comparative Example 1, a photospacer having a lower bottom line width of 10 μm or less with good appearance could be formed, but the sensitivity was low, and an exposure amount of 100 mJ / cm ² or more was required for pattern formation.

  In Comparative Example 2, although the sensitivity is high, it is difficult to form a photo spacer having a lower bottom line width of 10 μm or less without peeling, and the pattern line width is increased at an exposure amount that can be formed without peeling. Therefore, it was impossible to form a small-diameter pattern.

本発明の感光性樹脂組成物を用いることにより、低露光量にて小径パターンのフォトスペーサーを形成することが可能となり、高精細のカラーフィルタ製造における生産性の向上が可能となる。

By using the photosensitive resin composition of the present invention, it is possible to form a photo spacer having a small diameter pattern with a low exposure amount, and it is possible to improve productivity in manufacturing a high-definition color filter.

DESCRIPTION OF SYMBOLS 1 ... Color filter 2 ... Transparent substrate 3 ... Light shielding layer 4 ... Colored layer 4R ... Red pixel 4G ... Green pixel 4B ... Blue pixel 5 ... Photo spacer

Claims (4)

A photosensitive resin composition for forming a photospacer comprising a photopolymerization initiator, a binder polymer, a photosensitive monomer, a surfactant, and a solvent,
The photo-spacer-forming photosensitive resin composition is laminated on a light-shielding layer on a transparent substrate as a photo-spacer constituting a color filter for a liquid crystal display device,
The photopolymerization initiator contains a fluorene-based oxime ester compound represented by Formula 1;

[In the chemical formula 1, X ¹ represents R ¹¹ , OR ¹¹ , COR ¹¹ , SR ¹¹ , CONR ¹² R ¹³ or CN, and X ² · X ³ · X ⁷ may have a substituent. An alkyl group having 1 to 20 atoms, an aryl group having 6 to 30 carbon atoms which may have a substituent, an arylalkyl group having 7 to 30 carbon atoms which may have a substituent or a substituent; And X ⁴ represents R ¹¹ , OR ¹¹ , COR ¹¹ , SR ¹¹ , CONR ¹² R ¹³ , NO ₂ , SO ₄ H, CN, Represents a halogen atom or a hydroxyl group, and X ⁵ and X ⁶ are each independently R ¹¹ , OR ¹¹ , SR ¹¹ , COR ¹¹ , CONR ¹² R ¹³ , NR ¹² COR ¹¹ , OCOR ¹¹ , COOR ¹¹ , SCOR ¹¹ , COSR ¹¹ , COSR ¹¹ , CSOR ¹¹ , CN, a halogen atom or a hydroxyl group. R ¹¹ , R ¹² and R ¹³ are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 20 carbon atoms, or an optionally substituted carbon atom having 6 to 6 carbon atoms. It represents a 30 aryl group, an optionally substituted arylalkyl group having 7 to 30 carbon atoms, or an optionally substituted heterocyclic group having 2 to 20 carbon atoms. a and b are each independently 0-3. ] The photosensitive resin composition for forming a photospacer according to claim 1, wherein the fluorene-based oxime ester compound is represented by Formula 2.

The photosensitive resin composition for forming a photospacer according to claim 1, wherein the fluorene-based oxime ester compound is represented by Formula 3.

  A color filter comprising a photospacer using the photosensitive resin composition for forming a photospacer according to any one of claims 1 to 3.

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