JP5498051B2 - Bulkhead and color filter - Google Patents

Description

The present invention relates to a partition wall and a color filter .

  A color filter usually forms a black matrix (black matrix) on the surface of a transparent substrate such as glass or plastic sheet, and then successively forms three or more different hues such as red, green, blue, etc. in stripes or It is formed with a color pattern such as a mosaic. The pattern size varies depending on the use of the color filter and each color, but is generally about 5 to 700 μm. Further, the positional accuracy of superposition is several μm to several tens of μm, and is manufactured by a fine processing technique with high dimensional accuracy.

  Typical methods for producing a color filter include a dyeing method, a printing method, a pigment dispersion method, and an electrodeposition method. Among these, in particular, a pigment dispersion method for forming a color filter image by coating a photopolymerizable composition containing a color material on a transparent substrate and repeating image exposure, development, and curing as necessary is a color filter. It is widely used because it has a high accuracy such as pixel position and film thickness, is excellent in durability such as light resistance and heat resistance, and has few defects such as pinholes.

  Of these, the black matrix is generally arranged in a grid, stripe, or mosaic pattern between the red, green, and blue color patterns. The contrast is improved by suppressing color mixing between colors, or the TFT malfunctions due to light leakage. Play a role to prevent. For this reason, the black matrix is required to have high light shielding properties. Conventionally, the black matrix is generally formed by a metal film such as chromium. In this method, a metal such as chromium is vapor-deposited on a transparent substrate, and the chromium layer is etched through a photolithography process. Therefore, a high light-shielding property can be obtained with a small thickness and high accuracy. On the other hand, it is a method with a long manufacturing process and low productivity, and has problems such as high costs and environmental problems caused by waste liquid from etching processing.

  In order to solve these problems, Patent Document 1 proposes a photolithography method using a photosensitive resin. However, for the resin light-shielding film obtained by this method, it is necessary to increase the content of the light-shielding pigment or the like in order to develop a light-shielding property (optical density) equivalent to that of a black matrix made of a metal film such as chromium. However, in the case where a light blocking ability is required in the entire light wavelength region, such as a resin black matrix, the light-shielding pigment absorbs ultraviolet rays in the process of photocuring by irradiating with ultraviolet rays. However, there is a difference in crosslink density with respect to the film thickness direction, and even if it is sufficiently photocured on the coating surface, it is difficult to photocure on the basal plane. 2) The difference in crosslink density between exposed and unexposed areas 3) Black resist photosensitivity, resolution, adhesion, developability, edge shape, etc. There is a problem in terms of sharpness, etc. of.

  In Patent Document 2, an unsaturated group-containing compound obtained by reacting a reaction product of a specific aromatic epoxy compound and (meth) acrylic acid with a polybasic acid carboxylic acid or its anhydride is used as a resin main component. The black resist contained as a component has a high light-shielding rate, facilitates the formation of fine patterns by photolithography, and has excellent light-shielding properties such as insulation, heat resistance, adhesion, and room temperature storage stability. It has been reported that it becomes a composition for forming a thin film. However, this Patent Document 2 is suitable for a black resist for a thin film having a standard thickness of 1 μm, which is a standard film thickness of the black matrix, and is related to photocurability, development characteristics, etc. with a film thickness exceeding 1.5 μm. Is not mentioned.

  In order to achieve high brightness and high definition, the resin black matrix, which is one of the color filter related materials, has been mainly used for thin films with a film thickness of about 1 μm. High light-shielding is required, and a new resin black matrix with a film thickness exceeding 1.5 μm has also appeared. Recently, panels that have introduced color filter-on-array technology are attracting attention. This technology integrates a color filter substrate and a TFT array substrate, and does not require precise alignment of the two substrates, and it makes the red, blue, and green pixels of the color filter as fine as possible. Can lead to higher definition of the panel. However, such a resin black matrix for color filter on array requires a high light-shielding property, and therefore generally requires a film thickness of 2 μm or more.

  However, as the film thickness of the resin black matrix increases, the difference in crosslink density in the film thickness direction at the exposed part increases, making it more difficult to achieve high sensitivity and obtain a well-shaped black pattern. Become. Furthermore, in the subsequent thermal firing process, there is a difference in the crosslink density in the film thickness direction at the exposed part, resulting in a difference in thermal curing shrinkage between the coating surface and the substrate, increasing the coating surface roughness. As a result, the surface smoothness deteriorates, wrinkles occur on the surface, and the subsequent formation of red, blue, and green pixels may be adversely affected.

  Thus, examples of color filter-related materials suitable for thick films can be found in Patent Documents 3-6. However, Patent Document 3 is a method that requires a long time for film formation because it is a method of forming a film to about 1.5 to 1.8 μm by repeating thin film printing by a printing method, and not a resin black matrix, Since the content relates to a method of forming a color matrix such as red, blue, and green, the light shielding ability is insufficient for use as a light shielding film. Further, Patent Document 4 is a method of forming a thick film by back light, but this is also not using black but blue as a light shielding film, which is not sufficient in terms of light shielding properties. Since different back exposure is performed, problems remain in terms of productivity and yield. Furthermore, patent document 5 is the content regarding the protective film for color filters excellent in the planarization performance which mix | blended inorganic oxide sol, and when a light shielding film is formed using the composition of this literature description, light-shielding ability is There is a great shortage.

  Furthermore, Patent Document 6 exemplifies a photosensitive resin composition for resin black matrix containing granular silica. When a photosensitive resin composition (coating film) applied on a transparent substrate is cured to form a partition (black matrix), the coating is usually photocured and developed to form a predetermined pattern of partitioning. Thereafter, heat treatment (post-bake) is performed. As described above, only photocuring may cause insufficient curing on the base surface side in the thickness direction of the coating film, and the partition walls are finally formed by post-baking. However, as shown in FIG. 2, when the coated film 2 after development (in the state shown in FIG. 2 (a), 2a is a photocured portion) is post-baked, it becomes a partition wall with a skirt on the substrate side. (State shown in FIG. 2B). This is because a part of the resin is softened by heat, which is a so-called sagging phenomenon. Therefore, the invention described in Patent Document 6 ensures the shape stability after post-baking by including granular silica in the resin composition, and is ultimately represented by reference numeral 3 in FIG. In addition, the aim is to form partition walls that maintain the shape of the coated film as much as possible.

  However, since granular silica has high cohesive force, there is room for improvement in terms of dispersion stability. Further, when the photosensitive resin composition containing the granular silica is applied to a substrate and then dried or post-baked, the silica particles are aggregated with each other due to high cohesive force, and thus are used as a light-shielding component. When the distance between the carbon black particles approaches, the volume resistivity may decrease. Furthermore, since granular silica has low affinity for organic solvents, it is necessary to add a certain amount or more in order to ensure shape stability after post-baking, but if the content of granular silica increases, pattern linearity May adversely affect the development characteristics.

  By the way, although a large amount of a light-shielding component has been tried as a means for achieving high light-shielding properties, when a conductive material such as carbon is used as a pigment, the volume resistance of the black matrix decreases, and a display device or the like. There is a risk of reducing the reliability.

JP-A-4-177202 JP-A-8-278629 JP-A-5-045513 Japanese Patent Laid-Open No. 5-181009 JP-A-5-288926 JP 2008-304583 A

  Therefore, the present inventors have excellent shape stability when a coating film coated with a photosensitive resin composition is cured, and particularly has excellent development characteristics even when a thick film containing a light shielding component is formed. As a result of earnestly examining a photosensitive resin composition that can obtain a film and excellent in dispersion stability, it has been found that all the conventional problems can be solved by blending predetermined acrylic resin particles. Completed the invention.

Therefore, the object of the present invention is to solve the above-mentioned problems. For example, even when a cured film having a thickness exceeding 1.5 μm is obtained, the pattern dimensional stability is excellent, the development margin, and the edge shape of the pattern. A partition obtained by using a photosensitive resin composition that does not have a decrease in volume resistance even when a conductive material such as carbon is used as a light-shielding component. It is to provide.

Another object of the present invention is to provide a color filter in which pixels are formed on a substrate provided with partition walls obtained by using this photosensitive resin composition.

That is, the present invention is a partition partitioning a plurality of pixel regions on a substrate, and (a) a photocurable resin and / or a photocurable monomer, and (b) acrylic resin particles as essential components, (B) The average value of the primary particle diameter of the acrylic resin particles of the component is 50 to 200 nm, and the weight ratio of the acrylic resin particles (b) to the photocurable resin and / or the photocurable monomer (A) ( (B) / (b)) is applied to a photosensitive resin composition in the range of 0.1 to 2.0 on a substrate and dried, then (a) exposure by an ultraviolet exposure device, (b) by an alkaline aqueous solution. The partition wall is characterized by having each step of development and (c) heat treatment as essential, having a height of 1.5 to 4 μm and a taper angle of 60 ° or more .

In addition, the present invention is a color filter in which pixels are formed on a substrate provided with the above partition walls .

  The photosensitive resin composition of the present invention is excellent in dispersion stability, and is excellent in shape stability when cured, and also has excellent development characteristics. Therefore, display element materials such as color filters, EL elements, etc. Useful as. In particular, it is suitable for obtaining a thick cured film containing a light-shielding component. For example, even when obtaining a thick black matrix of about 1.5 μm or more, it has excellent pattern dimension stability and development. A pattern with good margins, sharpness of the edge shape of the pattern, and the like can be obtained. Furthermore, the photosensitive resin composition of the present invention can reduce the decrease in volume resistance as much as possible even when a conductive material such as carbon is used as the light shielding component.

FIG. 1 is an explanatory cross-sectional view showing a state of a cured film (partition) formed on a substrate. FIG. 2 is a cross-sectional explanatory view showing a state of curing of the photosensitive resin composition (coating film) in the conventional example.

Hereinafter, the present invention will be described in detail.
The composition of the present invention contains the components (a) and (b) as essential components, and when a light-shielding cured film is obtained, the components (c) are further included as essential components. Here, it is preferable that the photocurable resin as the component (a) is, for example, the following unsaturated group-containing compound. That is, (meth) acrylic acid (which means “acrylic acid and / or methacrylic acid”) is reacted with an epoxy compound having two glycidyl ether groups derived from bisphenols, and the resulting hydroxy group is obtained. It is an epoxy (meth) acrylate acid adduct obtained by reacting a polybasic acid carboxylic acid or an anhydride thereof with a compound having the above. Here, the epoxy compound derived from bisphenols means an epoxy compound obtained by reacting bisphenols with epihalohydrin. Such an epoxy compound and an unsaturated group-containing compound (epoxy (meth) acrylate acid adduct) derived from the epoxy compound are known from Patent Document 2 and the like, and such compounds can be widely used.

  In the above case, since the photocurable resin as component (a) has both an ethylenically unsaturated double bond and a carboxyl group, the photocurable resin composition has excellent photocurability, good developability, and patterning characteristics. Improves physical properties of the cured film.

（但し、式中、Ｒ₁及びＲ₂は、独立に水素原子、炭素数１〜５のアルキル基、フェニル基又はハロゲン原子のいずれかであり、Ｘは独立に単結合、−ＣＯ−、−ＳＯ₂−、−Ｃ（ＣＦ₃）₂−、−Ｓｉ（ＣＨ₃）₂−、−ＣＨ₂−、−Ｃ（ＣＨ₃）₂−、−Ｏ−又は下記式（２）で表される９，９−フルオレニル基を示し、ｎは０〜１０の数である）

That is, the photocurable resin as component (a) is preferably derived from an epoxy compound represented by the following general formula (1). This epoxy compound is derived from bisphenols. Therefore, since an unsaturated group-containing compound is understood by explaining bisphenols, preferred specific examples will be explained by bisphenols.

(In the formula, R ₁ and R ₂ are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group or a halogen atom, and X is independently a single bond, —CO—, — SO ₂ —, —C (CF ₃ ) ₂ —, —Si (CH ₃ ) ₂ —, —CH ₂ —, —C (CH ₃ ) ₂ —, —O— or 9 represented by the following formula (2) , 9-fluorenyl group, n is a number from 0 to 10)

  Examples of bisphenols that give preferable unsaturated group-containing compounds include the following. Bis (4-hydroxyphenyl) ketone, bis (4-hydroxy-3,5-dimethylphenyl) ketone, bis (4-hydroxy-3,5-dichlorophenyl) ketone, bis (4-hydroxyphenyl) sulfone, bis (4 -Hydroxy-3,5-dimethylphenyl) sulfone, bis (4-hydroxy-3,5-dichlorophenyl) sulfone, bis (4-hydroxyphenyl) hexafluoropropane, bis (4-hydroxy-3,5-dimethylphenyl) Hexafluoropropane, bis (4-hydroxy-3,5-dichlorophenyl) hexafluoropropane, bis (4-hydroxyphenyl) dimethylsilane, bis (4-hydroxy-3,5-dimethylphenyl) dimethylsilane, bis (4- Hydroxy-3,5-dichlorophenyl) dimethyl Silane, bis (4-hydroxyphenyl) methane, bis (4-hydroxy-3,5-dichlorophenyl) methane, bis (4-hydroxy-3,5-dibromophenyl) methane, 2,2-bis (4-hydroxyphenyl) ) Propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane, 2,2-bis (4-hydroxy-) 3-methylphenyl) propane, 2,2-bis (4-hydroxy-3-chlorophenyl) propane, bis (4-hydroxyphenyl) ether, bis (4-hydroxy-3,5-dimethylphenyl) ether, bis (4 -Hydroxy-3,5-dichlorophenyl) ether or the like, or X is the 9,9-fluorenyl group 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 9,9-bis (4-hydroxy-3-chlorophenyl) fluorene, 9,9 -Bis (4-hydroxy-3-bromophenyl) fluorene, 9,9-bis (4-hydroxy-3-fluorophenyl) fluorene, 9,9-bis (4-hydroxy-3-methoxyphenyl) fluorene, 9, 9-bis (4-hydroxy-3,5-dimethylphenyl) fluorene, 9,9-bis (4-hydroxy-3,5-dichlorophenyl) fluorene, 9,9-bis (4-hydroxy-3,5-dibromo Phenyl) fluorene and the like, and further compounds such as 4,4′-biphenol and 3,3′-biphenol.

  The photocurable resin as the component (a) is preferable because it is obtained from an epoxy compound derived from the above bisphenols, and is excellent in transparency, heat resistance, development characteristics and the like. In addition to such an epoxy compound, a phenol novolac type epoxy compound, a cresol novolac type epoxy compound, or the like can be used as long as it contains a compound having two glycidyl ether groups. In addition, when bisphenols are converted to glycidyl ether, oligomer units are mixed. If the average value of n in formula (1) is in the range of 0 to 10, preferably 0 to 2, the present resin composition. There is no problem in the performance of things.

  In addition, as the polybasic acid carboxylic acid or its acid anhydride that can react with the hydroxy group in the epoxy (meth) acrylate molecule obtained by reacting such an epoxy compound with (meth) acrylic acid, for example, Maleic acid, succinic acid, itaconic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, methylendomethylenetetrahydrophthalic acid, chlorendic acid, methyltetrahydrophthalic acid, trimellitic acid, pyromellitic acid and the acid anhydride thereof, Furthermore, aromatic polyvalent carboxylic acids such as benzophenone tetracarboxylic acid, biphenyl tetracarboxylic acid, biphenyl ether tetracarboxylic acid, and acid dianhydrides thereof can be used. And about the usage-amount of an acid anhydride and an acid dianhydride, the ratio suitable for forming a fine pattern by exposure and alkali image development operation can be selected.

  About (a) component photocurable resin, only the 1 type may be used and 2 or more types of mixtures can also be used. In addition, the reaction between the epoxy compound and (meth) acrylic acid, and the reaction between the epoxy (meth) acrylate obtained by this reaction and the polybasic acid or its acid anhydride employs a method known in Patent Document 2 above. There is no particular limitation.

  In addition, since the component (a) in the present invention only needs to be cured (polymerized) by light, only the component (monomer) that is not resinized in the uncured state of the photosensitive resin composition is included. Including cases. That is, the photocurable monomer used as the component (a) is a photopolymerizable monomer having at least one ethylenically unsaturated bond, such as 2-hydroxyethyl (meth) acrylate, 2- Monomers having hydroxyl groups such as hydroxypropyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (Meth) acrylate, tetramethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, pentaerythritol di (meth) acrylate, pentae List of (meth) acrylic esters such as lithitol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, glycerol (meth) acrylate, etc. These compounds can be used alone or in combination of two or more thereof.

  The photosensitive resin composition of the present invention contains the photopolymerizable compound of component (a), but preferably contains a photopolymerization initiator in order to photocure it. The photopolymerization initiator generates radical species upon irradiation with ultraviolet light, and is added to the photopolymerizable compound to start radical polymerization and cure the resin composition.

  Photopolymerization initiators include benzophenone, Michler's ketone, N, N'tetramethyl-4,4'-diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 4,4'-diethylaminobenzophenone, 2-ethylanthraquinone, Aromatic ketones such as phenanthrene, benzoin ethers such as benzoin methyl ether, benzoin ethyl ether and benzoin phenyl ether, benzoins such as methyl benzoin and ethyl benzoin, 2- (o-chlorophenyl) -4,5-phenylimidazole dimer 2- (o-chlorophenyl) -4,5-di (m-methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxy Phenyl) -4,5-diphenylimidazole dimer, 2,4,5-triarylimidazole dimer, 2-benzyl-2-dimethylamino-1- (4-molybdenum) Ruphorinophenyl) -butanone, 2-trichloromethyl-5-styryl-1,3,4-oxadiazole, 2-trichloromethyl-5- (p-cyanostyryl) -1,3,4-oxadiazole, Halomethylthiazole compounds such as 2-trichloromethyl-5- (p-methoxystyryl) -1,3,4-oxadiazole, 2,4,6-tris (trichloromethyl) -1,3,5-triazine, 2-methyl-4,6-bis (trichloromethyl) -1,3,5-triazine, 2-phenyl-4, 6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-chlorophenyl) ) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- ( 4-methoxynaphthyl) -4,6-bis (trichloroRmethyl) -1,3,5-triazine, 2- (4-methoxystyryl) -4,6-bis (trichloromethyl) -1,3,5- Triazine, 2- (3,4,5-trimethoxys Halomethyl such as lyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-methylthiostyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine -S-triazine compounds, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone, 2-benzyl-2 Photopolymerization initiators such as 2-dimethylamino-1- [4-morpholinophenyl] -butanone-1,1-hydroxy-cyclohexyl-phenylketone, and oxime ester systems as described in JP-T-2004-534794 Initiators are mentioned.

  These photoinitiators can be used individually or in mixture of 2 or more types. In addition, although it does not act as a photopolymerization initiator or sensitizer by itself, it is also possible to add a compound that can increase the ability of the photopolymerization initiator or sensitizer by using in combination with the above compound. it can. Examples of such compounds include tertiary amines such as triethanolamine which are effective when used in combination with benzophenone.

  The use amount of the photopolymerization initiator is suitably 7 to 50 parts by weight based on 100 parts by weight of the total of component (a). When the blending ratio of the photopolymerization initiator is less than 7 parts by weight, the rate of photopolymerization becomes slow and the sensitivity decreases. On the other hand, when it exceeds 50 parts by weight, the sensitivity is too strong and the pattern line The width becomes thicker than the pattern mask, and there is a possibility that a line width that is faithful to the mask cannot be reproduced, or that the pattern edge does not become jagged and sharp.

  (B) Component acrylic resin particles are not limited by the production method or shape (spherical, non-spherical, mononuclear structure, core-shell structure, etc.), but have low cohesiveness and excellent dispersibility, and the photosensitivity. In order to make the taper angle of the cured film obtained by applying and drying the resin composition on the substrate, drying through an ultraviolet exposure device, developing with an alkaline aqueous solution, and heat treatment to be 60 ° or more, spherical, mononuclear A structure is preferred. Here, the taper angle of the cured film is a substrate side of a cured film (a partition wall in the case of a color filter or the like) obtained by developing into a predetermined shape and heat-treating as shown in the cross-sectional explanatory diagram of FIG. Say the angle θ made by. When the taper angle is 60 ° or more, it means that the shape stability of the obtained cured film is excellent. The upper limit of the taper angle is theoretically 90 ° except in the case of using an inversely tapered shape.

  Moreover, the average value of the primary particle diameter of acrylic resin particles needs to be in the range of 50 to 200 nm, and preferably in the range of 70 to 150 nm. Here, the average value of the primary particle diameter of the particles is observed with a transmission electron microscope, 100 particles are selected at random, and the major axis length and minor axis length of the particles are measured. Calculate by arithmetic mean. In that case, when the aggregate and the aggregate are comprised, the primary particle refers to the particle | grains which comprise these. If the average primary particle diameter of the acrylic resin particles is less than 50 nm, it is not preferable from the viewpoint of dispersibility. On the contrary, when it exceeds 200 nm, the surface roughness is deteriorated, which is not preferable in terms of maintaining the volume resistance value. In addition, in order to improve the shape stability, if the particle size becomes too large, the volume ratio of the particles to the particle weight decreases, so it is necessary to add a large amount of acrylic resin particles, and maintain good developability for alkaline aqueous solutions. It is difficult to do. The photosensitive resin composition to which acrylic resin particles having a particle diameter exceeding 200 nm are added in a range where good developability can be maintained is applied on the substrate, dried, then exposed to an ultraviolet exposure device, developed with an alkaline aqueous solution, and subjected to heat treatment. The cured film obtained through each step has a crushed shape like a so-called sagging phenomenon, and its side surface has an arc shape. The particle size distribution of the acrylic resin particles is not particularly limited, but is 80% or more in the range of ± 3σ with respect to the average value of the primary particle diameters obtained by the above method in order to maintain the particle dispersibility. Is preferred.

  Regarding the blending ratio of the acrylic resin particles, the weight ratio ((b) / (b)) between the acrylic resin particles (b) and the photocurable resin and / or the photocurable monomer (b) in the composition is The range is from 0.1 to 2.0, preferably from 0.5 to 1.5. If the weight ratio is less than 0.1, the effect of improving the shape stability of the cured film is poor, whereas if it exceeds 2.0, the development performance may be reduced or the volume resistance value may be reduced. In the present invention, the resin composition may contain the light-shielding component (c). In that case, it can be considered that a part of the acrylic fine particles is replaced with the light-shielding component. B), and the weight ratio ((b) + (c) / (b)) between the total weight of the light-shielding component (c) and the photocurable resin and / or the photocurable monomer (b) is 0. The range is from 1 to 2.0, preferably from 0.5 to 1.5. The meanings of the lower limit and the upper limit of the weight ratio in this case are the same as those described above.

  The surface of the acrylic resin particles (b) is preferably acid-treated. By applying surface acid treatment, the particle dispersibility is improved, and after the photosensitive resin composition is applied on the substrate and dried, the developability with an alkaline aqueous solution after exposure by an ultraviolet exposure device is further improved, and linearity is improved. A good pattern can be obtained.

  Moreover, the photosensitive resin composition of this invention can also be made into the aspect which mix | blends a light-shielding component (c) and obtains a light-shielding cured film. The light-shielding component (c) is at least one selected from black organic pigments, mixed-color organic pigments and light-shielding materials, and the (c) component light-shielding component is excellent in heat resistance, light resistance and solvent resistance. It is preferable. Here, examples of the black organic pigment include perylene black and cyanine black. Examples of the mixed color organic pigment include those obtained by mixing at least two pigments selected from red, blue, green, purple, yellow, cyanine, magenta and the like into a pseudo black color. Examples of the light shielding material include carbon black, chromium oxide, iron oxide, titanium black, aniline black, and cyanine black. Two or more types can be appropriately selected and used. The surface smoothness, dispersion stability, and compatibility with the resin are preferable.

  (C) About the compounding ratio of a component, it is 50-150 weight with respect to a total of 100 weight part of said (I) component (a total of 100 weight part including this when it contains a photoinitiator component). Good part. When the amount is less than 50 parts by weight, the light shielding property is not sufficient. When the amount exceeds 150 parts by weight, the content of the photosensitive resin as the original binder is decreased, which causes an undesired problem that the development characteristics are impaired and the film forming ability is impaired.

  In the photosensitive resin composition of the present invention, it is preferable to use a solvent in addition to the components (A) to (C). Examples of the solvent include alcohols such as methanol, ethanol, n-propanol, isopropanol, ethylene glycol and propylene glycol, terpenes such as α- or β-terpineol, acetone, methyl ethyl ketone, cyclohexanone, N-methyl-2- Ketones such as pyrrolidone, aromatic hydrocarbons such as toluene, xylene, tetramethylbenzene, cellosolve, methyl cellosolve, ethyl cellosolve, carbitol, methyl carbitol, ethyl carbitol, butyl carbitol, propylene glycol monomethyl ether, propylene Glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, triethylene glycol monomethyl ether, Glycol ethers such as reethylene glycol monoethyl ether, ethyl acetate, butyl acetate, cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, carbitol acetate, ethyl carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, propylene glycol mono Examples include acetic acid esters such as ethyl ether acetate, and the like, and these can be dissolved and mixed to form a uniform solution-like composition.

  Moreover, the photosensitive resin composition of the present invention may contain additives such as a curing accelerator, a thermal polymerization inhibitor, a plasticizer, a filler, a solvent, a leveling agent, and an antifoaming agent as necessary. . Examples of the thermal polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, pyrogallol, tert-butylcatechol, phenothiazine and the like, and examples of the plasticizer include dibutyl phthalate, dioctyl phthalate, tricresyl and the like. Examples of foaming agents and leveling agents include silicon-based, fluorine-based, and acrylic compounds.

  The photosensitive resin composition of the present invention has a total of 70 wt% or more of the components (a) to (c) in the solid content excluding the solvent (the solid content includes a monomer that becomes a solid content after curing), preferably Is preferably 80 wt%, more preferably 90 wt% or more. The content ratio of the solvent in the resin composition is preferably in the range of 50 to 90 wt% although the optimum viscosity range varies depending on the coating machine used for coating.

  Moreover, about the cured film of this invention, it can form by the photolithographic method using the photosensitive resin composition of this invention mentioned above. As the manufacturing process, first, the photosensitive resin composition is applied to the substrate surface as a solution, and then the solvent is dried (prebaked), and then a photomask is applied on the coating thus obtained, Examples include a method in which an exposed portion is cured by irradiating ultraviolet rays, a pattern is formed by performing development in which an unexposed portion is eluted with an alkaline aqueous solution, and post-baking is performed as post-drying.

  As a substrate on which the solution of the photosensitive resin composition is applied, a glass, a transparent film (for example, polycarbonate, polyethylene terephthalate, polyether sulfone, etc.) on which a transparent electrode such as ITO or gold is deposited or patterned is used. It is done.

  As a method of applying the photosensitive resin composition solution to the substrate, known means can be applied. For example, any of a solution dipping method, a spray method, a roller coater machine, a land coater machine, a spinner machine, etc. This method can also be adopted. After applying to a desired thickness by these methods, the film is formed by removing the solvent (pre-baking). Pre-baking is performed by heating with an oven, a hot plate or the like. The heating temperature and heating time in the pre-baking are appropriately selected according to the solvent used, and for example, the heating is performed at a temperature of 80 to 120 ° C. for 1 to 10 minutes.

  The exposure performed after pre-baking can be performed by an exposure machine, and only the resist corresponding to the pattern is exposed by exposing through a photomask. The exposure machine and the exposure irradiation conditions are appropriately selected, and exposure is performed using a light source such as an ultra-high pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, or a deep ultraviolet lamp, and the resin composition in the coating film is photocured.

  The alkali development after the exposure is performed for the purpose of removing the resist in the unexposed portion, and a desired pattern is formed by this development. Examples of the developer suitable for the alkali development include, for example, an aqueous solution of an alkali metal or alkaline earth metal carbonate, an aqueous solution of an alkali metal hydroxide, and the like. Particularly, sodium carbonate, potassium carbonate, carbonate It is preferable to develop at a temperature of 20 to 30 ° C. using a weakly alkaline aqueous solution containing 0.05 to 3% by weight of a carbonate such as lithium, and a fine image using a commercially available developing machine or ultrasonic cleaner. Can be formed precisely.

After the development as described above, a heat treatment (post-bake) is performed at a temperature of 180 to 250 ° C. and a condition of 20 to 100 minutes, for example. This post-baking is performed for the purpose of improving the adhesion between the patterned light-shielding film and the substrate. This is performed by heating with an oven, a hot plate or the like, as in the pre-baking. The patterned cured film of this invention is formed through each process by the above photolithography method. The cured film obtained from the resin composition of the present invention has a volume resistance of 10 ¹⁰ Ωcm or more, preferably 10 ¹² Ωcm or more. In particular, when a partition wall is formed, a material having a height of 1.5 to 4 μm and a taper angle of 60 ° or more can be obtained. Moreover, since it can also achieve 2.0-4.5 / micrometer also about OD value (optical density), it is suitable as a black matrix for color filters for color filters which have high light-shielding property and high resistance value. Moreover, it can be suitably used as a black matrix for a color filter corresponding to an inkjet process.

  As described above, the photosensitive resin composition of the present invention is suitable for forming a fine pattern by operations such as exposure and alkali development, but the same curing can be achieved even if the pattern is formed by conventional screen printing. A membrane can be obtained.

  The photosensitive resin composition of the present invention can be suitably used as a coating material for forming a cured film, and in particular, each color filter of R, G, B, etc. used for a liquid crystal display device or a photographing element. In addition to the formation of a light-shielding film such as ink for ink and black matrix (partition), it is useful as a black matrix for liquid crystal projection. Furthermore, the photosensitive resin composition of the present invention includes various multicolor display ink materials such as a color liquid crystal display device, a color facsimile, and an image sensor in addition to the color filter ink of the color liquid crystal display as described above, The present invention can also be applied to display element materials in EL elements and the like.

<Production Examples A-1 to A-7 and a-1 to a-2 of Acrylic Resin Particle-Containing Dispersion>
Acrylic resin particles (Nippon Paint Co., Ltd. fine spheres), polymer dispersant and propylene glycol monomethyl ether acetate are mixed in the proportions shown in Table 1, dispersed in a bead mill, and dispersion A-1 containing acrylic resin particles -A-4 and a-1 were prepared. Also, acrylic resin particles (Nippon Paint Finesphere), resin-coated carbon black (Mitsubishi Chemical Corporation MS18E, particle size 25 nm), polymer dispersant and propylene glycol monomethyl ether acetate as light-shielding pigment (light-shielding component) The mixture was mixed in the ratio shown in Table 1 and dispersed by a bead mill to obtain a dispersion A-5 containing both acrylic resin particles / light-shielding pigment. Similarly, instead of carbon black as a light-shielding pigment, both titanium resin (Mitsubishi Materials, particle size 30 nm) or mixed organic pigment black (Mikuni Dye, particle size 30 nm) is used for both acrylic resin particles / light-shielding pigments. Dispersions A-6 to A-7 containing the same were prepared. Dispersion a-2 of production number 9 was a dispersion containing no resin resin and containing only resin-coated carbon black (MS18E manufactured by Mitsubishi Chemical Corporation, particle size of 25 nm) as a light-shielding pigment. The acrylic resin particles used in production numbers 1 to 8 are all produced by controlling a single composition acrylic resin (mononuclear composition) to be spherical, and the average value of primary particle diameters. Is as shown in Table 1. In addition, those with production numbers 1, 4 to 8 are treated so that acidic functional groups are present on the particle surface, and those with production number 3 are such that basic functional groups are present on the particle surface. The production number 2 is a surface-untreated one. The average primary particle diameter of the particles is observed with a transmission electron microscope, 100 particles are selected at random, and the major axis length and minor axis length of the particles are measured. Obtained by arithmetic mean. At that time, when agglomerates and aggregates are formed, the primary particles are particles constituting these.

  The viscosity of the dispersion prepared above was measured at 20 rpm, 25.0 ± 0.5 ° C. using an E-type viscometer. Furthermore, the viscosity after standing at room temperature for 1 month and after storage at 40 ° C. for 1 week was measured, and the viscosity stability was evaluated based on the rate of change in viscosity. As a result, dispersions A-1, A-4 to A-7, and a-1 containing acrylic resin particles having acid treatment and mononuclear structure, and dispersion a-2 not containing acrylic resin particles were obtained at room temperature. When the viscosity was measured after standing for 1 month and after storing at 40 ° C. for 1 week, the rate of change in viscosity was less than 10% (indicated by ○ in Table 1). The viscosity change rate of the untreated acrylic resin particle dispersion A-2 and the base-treated acrylic resin particle dispersion a-2 was 10% or more (indicated by x in the table).

[Examples 1 to 11 and Comparative Examples 1 to 4]
<Preparation of photosensitive resin composition for partition walls>
Propylene glycol monomethyl ether acetate together with 0.30 part of silane coupling agent S-510 (manufactured by Shin-Etsu Chemical Co., Ltd.) after mixing the dispersion obtained above and each component shown in Table 2 in the ratio shown in the table. Was added to give a total amount of 100 parts by weight and a solid content concentration of 20% by weight. Furthermore, 0.005 part by weight of a silicon-based surfactant SH3775M (manufactured by Dow Corning Toray) was added, and the mixture was filtered using a 2 μm polypropylene membrane filter at a pressure of 0.2 kg / cm ² to obtain a photosensitive resin composition. Was prepared. In addition, the symbol of each component described in Table 2 represents the following, respectively.

a-3: Nanosilica dispersion, NANO BYK-3650 (by Big Chemie Japan, particle size 20-25nm)
B-1: Propylene glycol monomethyl ether acetate solution of acid anhydride polycondensate of epoxy acrylate having a fluorene skeleton (resin solid content concentration = 56.1% by weight, trade name V259ME manufactured by Nippon Steel Chemical Co., Ltd.)
C-1: Mixture of dipentaerythritol hexaacrylate and dipentaerythritol pentaacrylate (trade name DPHA, manufactured by Nippon Kayaku Co., Ltd.)
C-2: Trimethylolpropane triacrylate (trade name SARTOMER SR-351S manufactured by Sakai Kogyo)
D-1: Photopolymerization initiator, IRGACURE OXE01 (Ciba Japan)
D-2: Photopolymerization initiator, IRGACURE OXE02 (Ciba Japan)

Each photosensitive resin composition obtained above was applied on a 125 mm × 125 mm glass substrate using a spin coater so that the film thickness after post-baking was 2.1 μm, and prebaked at 80 ° C. for 1 minute. . After that, the exposure gap is adjusted to 80 μm, a negative photomask of line / space = 20 μm / 20 μm is covered on the dried coating film, and an ultraviolet ray of 100 mj / cm ² with an ultrahigh pressure mercury lamp with I-line illuminance of 30 mW / cm ² The photocuring reaction of the photosensitive part was performed.

Next, this exposed coated plate was subjected to 1 kgf / cm ² pressure shower development in a 0.05% aqueous potassium hydroxide solution at 23 ° C., and the time during which the pattern was observed was defined as the development omission time (BT seconds). After developing for ² seconds, spray washing with 5 kgf / cm ² pressure is performed to remove the unexposed part of the coating film to form a pixel pattern on the glass substrate, and then at 230 ° C. using a hot air dryer. Heat post-baked for 30 minutes. The evaluation items and methods of the cured films obtained in each Example and Comparative Example are as follows.

[Applied foreign matter]
The case where radial streaks were observed in the coating film after spin coating was evaluated as x <defect>, and the case where no radial streaks were observed was evaluated as o <good>.
[sensitivity]
Using a step mask, the exposure dose (mj / cm ² ) at which the remaining film was observed at BT (break time) +20 seconds was measured.
[Development adhesion]
A case where a 20 μm pattern remained at BT (break time) +40 seconds was indicated by ○, and a case where the peeled pattern was indicated by ×.
[Pattern linearity]
The 20 μm line after post-baking was observed with a microscope. In addition, the case where local wrinkles are observed is indicated by Δ.
[Film thickness and surface roughness (surface roughness Ra: JIS B0601-1994)]
It measured using the stylus type film thickness meter (made by Tencor Co., Ltd.). The surface roughness was Ra (Å) that can be placed 2 mm wide on the surface of the black matrix.
[Taper shape]
When the development time is omitted +10 to 30 seconds, the cross section of the 20 μm line after post-baking is observed with an operation electron microscope, and the angle between the substrate and the structure (cured film) taper is always 60 ° or more. Less than is Δ, and the case of an arc shape (FIG. 2, (b)) is ×.
[Volume resistance value]
A film having a thickness of 2.1 μm was formed after post-baking in the same manner as described above on a glass substrate on which chromium had been deposited on the entire surface. A 10 mmφ Al vapor deposition film was formed on the coating film, a voltage of 1 to 10 V was applied between Cr and Al, the current value was measured, and the resistance was determined.
[OD measurement]
It measured using the OD meter made from Otsuka Electronics, using the 2.1 micrometer coating film after post-baking, and described as OD value per micrometer.

  In each of Examples 1, 3, 4, and 6 to 11, the taper angle was 60 ° or more, and the volume resistance value also showed a good value. However, in Comparative Example 1 using acrylic resin particles having a large particle size and Comparative Example 2 in which no acrylic resin particles are present, the taper shape is always an arc shape, and in Comparative Example 2, the volume resistance was also reduced. . Further, Comparative Example 3 containing silica particles and Comparative Example 4 having a large amount of addition of acrylic resin particles had poor development characteristics.

[Example 12]
The photosensitive resin composition used in Examples 6 to 11, the opening (pixel region) is 300 μm × 100 μm, the line width is 30 μm, and the film thickness (height) is 2.1 μm. A matrix having was formed. Then, after treatment with an oxygen atmospheric plasma for 3 seconds, it was performed for 3 seconds treatment at CF ₄ atmospheric pressure plasma. When static contact angles were measured on this light-shielding partition (light-shielding film) using water or butyl carbitol acetate (BCA), they showed 100 ° and 50 °, respectively. Into this black matrix, using a TOSHIBA TEC inkjet head, ink of red, blue and green with a viscosity of 9 mPa · sec and a solid concentration of 20% is applied and post-baked at 230 ° C to form a color filter. did. As a result, a good color filter could be obtained.

1: Substrate 2: Coating film
2a: Cured part of the coating film 3: Ideal shape of the coating film after curing

Claims (8)

A partition partitioning a plurality of pixel regions on a substrate,
(B) photo-curable resin and / or photocurable monomer, and (b) as essential components an acrylic resin particle, (ii) the average value of primary particle diameter of the acrylic resin particles in component in 50~200nm Yes, the weight ratio ((b) / (b)) between the acrylic resin particles (b) and the photocurable resin and / or the photocurable monomer (b) is in the range of 0.1 to 2.0. After the photosensitive resin composition is applied onto a substrate and dried, (a) exposure by an ultraviolet exposure device, (b) development with an aqueous alkali solution, and (c) heat treatment are obtained as essential steps, and the height is 1 A partition wall having a thickness of 5 to 4 μm and a taper angle of 60 ° or more . The photosensitive resin composition further (c) a black organic pigment, it contains at least one light-blocking component selected from the color mixing organic pigments and the light-shielding material, an acrylic resin particles in the composition (ii) And the weight ratio ((b) + (c) / (b)) of the total weight of the light-shielding component (c) to the photocurable resin and / or the photocurable monomer (b) is 0.1 to The partition wall according to claim 1, which is in a range of 2.0. The partition according to claim 1 or 2, wherein the component (b) is a surface acid-treated acrylic resin particle. (A) component is the following general formula (1)

[Wherein, R ₁ and R ₂ are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group or a halogen atom, and X is independently a single bond, —CO—, — SO ₂ —, —C (CF ₃ ) ₂ —, —Si (CH ₃ ) ₂ —, —CH ₂ —, —C (CH ₃ ) ₂ —, —O— or 9 represented by the following formula (2) , 9-fluorenyl group, and n is a number from 0 to 10], and a reaction product of (meth) acrylic acid and a polybasic acid carboxylic acid or an anhydride thereof is further reacted. It consists of the obtained unsaturated group containing compound, The partition in any one of Claims 1-3 characterized by the above-mentioned.

The partition wall according to claim 2, wherein the light-shielding component of component (c) is carbon black. The partition wall according to any one of claims 1 to 5, which has a volume resistance value of 10 ¹⁰ Ωcm or more. The partition wall according to any one of claims 1 to 6, which has an OD value of 2.0 to 4.5 / µm. Color filter to form pixels on a substrate having a barrier rib according to any one of claims 1 to 7.

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