JPH08262216A - Production of color filter - Google Patents

Abstract

PURPOSE: To prevent the contamination of a photomask by contact with a photosensitive coating film and to increase the latitude of the shapes of a light shielding region and colored regions by developing an exposed positive type photosensitive coating film and coating a colored coating material by electrodeposition after exposing the transparent electrically conductive regions. CONSTITUTION: A transparent substrate with a light shielding region and transparent electrically conductive regions corresponding to separate image elements on the surface is prepd. and a positive photosensitive coating film is formed on at least the transparent electrically conductive regions. The photosensitive coating film is then exposed from the rear side of the substrate through a photo-mask. The exposed photosensitive coating film is developed and coated after exposing the transparent electrically conductive regions, with a colored coating material by electrodeposition to form colored regions. If such processes are carried out, the order and frequency of the processes may properly be selected and the processes may be combined with different processes in other method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter manufacturing method, and more particularly to a color filter manufacturing method suitable for a color liquid crystal display device.

[0002]

2. Description of the Related Art At present, as a color filter manufacturing method that is generally used, there are a dyeing method, a printing method, a pigment dispersion method, and the like, in which a transparent substrate is colored with a binder containing a dye or a pigment.

Since the dyeing method is a method of selectively dyeing a resin thin film on a substrate with a dye, it is necessary to carry out a dye-proofing step and a photolithography step each time the color is changed, which complicates the steps. There is a problem that the manufacturing cost becomes high due to the above. Further, since a dye is used as a coloring agent, there is a problem that heat resistance and weather resistance are inferior.
Although the printing method does not require anti-staining, there is a limit to the miniaturization of the color pattern, and there is a problem in that the accuracy of the printing position becomes worse as the display becomes higher in definition. In the pigment dispersion method, a fine pattern is possible, but a high-definition lithographic process has to be performed every time the color is changed, and the process is extremely complicated.

On the other hand, in order to eliminate these drawbacks, a method of manufacturing a color filter by an electrodeposition coating method has been proposed. In this method, it is general to form a transparent electrode in a predetermined pattern in advance, disperse an ionized polymer containing a dye or a pigment in a solvent, and apply a voltage to form a color filter. In addition to this, Japanese Patent Laid-Open No. 61-20
No. 3403, JP-A-61-272720 and JP-A-61-279803 disclose that a positive type photosensitive composition should be coated on a glass substrate having a transparent electrode to form a color filter. Is exposed and developed to expose the electrode surface, and a color filter is formed on the exposed transparent electrode by an electrodeposition method.

For example, in JP-A-61-272720, a conductive area is formed on a substrate, a positive type photosensitive coating film is formed on the conductive area, then exposed, and the exposed portion is developed and removed. A method of repeating a necessary number of steps of forming a colored region of a required color by electrodeposition is disclosed. In this method, a positive type photosensitive coating film is used, and only the exposed portion is solubilized in the developing solution. Therefore, exposure and development are repeated without peeling the photosensitive coating film.

In the method for producing a color filter by these electrodeposition coating methods, the photosensitive coating film is usually exposed through a photomask on the surface (front surface) on which the photosensitive coating film is formed. In the case of exposure from such a surface, for example, if the photosensitive coating film has tackiness or stain resistance, when the photomask is brought into contact with the photosensitive coating film, the photomask is contaminated and There is a problem that continuous use becomes difficult. Also, first the light-blocking area (black matrix)
And a photosensitive coating film is formed on the portion on the black matrix, if the black matrix is conductive, the photomask is precisely aligned to develop and color the portion. If the photosensitive coating film is only developed and the colored layer is not formed only on the developed portion, the colored layer may be formed on the black matrix. Furthermore, in this case, even if precise alignment of the photomask is performed, it is difficult to completely remove the photosensitive coating film at the boundary between the black matrix and each pixel during development, and the accuracy of forming the colored layer may be poor. There is a nature.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks and meet the above-mentioned demands, and there is no fear of contamination due to contact with the photosensitive coating film of the photomask.
It is an object of the present invention to provide a method for manufacturing a color filter that has a large degree of freedom in the shapes of the light-shielding area and the colored area, can easily cope with a large screen, and can be easily mass-produced.

[0008]

According to the present invention, there is provided a color filter manufacturing method characterized by comprising the following steps (A) to (C) (hereinafter referred to as the first method).
Will be provided.

(A) a step of forming a positive photosensitive coating film on at least the transparent conductive region of a transparent substrate having a light-shielding region and a transparent conductive region corresponding to each pixel on the surface,
(B) a step of exposing the positive photosensitive coating from the back surface of the transparent substrate through a photomask, and (C) developing the positive photosensitive coating exposed in the step (B) to be transparent. A step of forming a colored region by exposing the conductive region and then electrodepositing a colored electrodeposition paint. Further, according to the present invention, there is provided a method for producing a color filter (hereinafter, referred to as a second method), which comprises the steps (A), (B1) and (C1). To be done.

(B1) a step of forming a plurality of exposure areas having different exposure amounts in at least three stages on the positive photosensitive coating film by exposure from the back surface of the transparent substrate through a photomask, (C1) positive photosensitive Of the conductive coating film to expose the transparent conductive region, and then to electrocoat a colored electrodeposition coating composition on the exposed transparent conductive region, the exposure amount of the exposed region formed in the step (B1) A step of forming colored regions by sequentially repeating the steps from the largest. Further, according to the invention, in the first and second methods, the exposure of the positive type photosensitive coating film from the back surface of the transparent substrate through the photomask is performed more than the transparent conductive region corresponding to each pixel. Provided is a method for manufacturing a color filter, which is an exposure of a wide area and does not exceed an adjacent light-shielding area.

The present invention will be described in more detail below. In the first and second methods of the present invention, a step of forming a positive photosensitive coating film on at least the transparent conductive region of a transparent substrate having a light-shielding region and a transparent conductive region corresponding to each pixel on the surface ( Hereinafter, the step (A)) is provided.

The transparent substrate having a light-shielding region and a transparent conductive region corresponding to each pixel on the surface means, for example, a light-shielding region as a light-shielding film used for a liquid crystal display device such as a black matrix, that is, light is substantially emitted. There is no particular limitation as long as it is a substrate provided with a light-shielding region having a function of shielding and a transparent conductive region that is transparent and has conductivity to the extent that electrodeposition coating is possible. For example, light shielding area / transparent conductive area /
A laminated body such as a transparent substrate or a three-layer structure formed in the order of transparent conductive region / light-shielding region / transparent substrate, in which a pattern corresponding to subpixels as pixels of three primary colors is opened in the light-shielding region, A substrate having a structure in which a transparent conductive region is exposed in the opening may be used. The light-shielding layer does not necessarily have to cover the entire surface of the transparent substrate, and may be formed by appropriately removing the outer frame portion, for example.

Examples of the material of the transparent substrate include glass, various laminated plates, various plastic plates and the like. It is desirable that the surface of the substrate is smooth in view of the performance of the color filter, and the surface can be polished before use if necessary.

The transparent conductive region formed on the transparent substrate is usually formed by forming a transparent conductive film on the substrate. Examples of the transparent conductive film include a transparent conductive material containing tin oxide, indium oxide, antimony oxide, or a mixture thereof. The thickness of the transparent conductive film is usually preferably 20 to 300 nm. The method of forming the transparent conductive region on the transparent substrate is not particularly limited, and examples thereof include known coating methods such as a spray method, a CDV method, a sputtering method, and a vacuum deposition method using the above materials. It is desirable to use the transparent conductive region having the highest possible transparency in view of the performance of the color filter.

As a material for forming the light-shielding region provided on the transparent substrate, for example, chromium, chromium oxide / chromium,
Examples thereof include metals such as molybdenum, nickel, iron oxide and tantalum, metal oxides, and mixtures thereof.
The method for forming the light-shielding region is not particularly limited, and the light-shielding region can be formed by applying the above-mentioned material by a known method such as a plating method, a sputtering method, a CVD method, or a vacuum vapor deposition method. Other examples of the light-shielding region include a light-shielding region made of a fine powder of metal or metal oxide, a resin dispersion such as a paint in which a light blocking agent such as carbon black, a dye, a pigment is dispersed. Such a light-shielded area is formed by the dip method,
It can be formed by a known method such as a printing method, an electrodeposition method, or a lithography method using a photosensitive resin.

The positive type photosensitive coating film formed on at least the transparent conductive region of the transparent substrate is not particularly limited as long as it is a positive type photosensitive material in which an exposed portion is eluted with a developing solution, and it is conventionally known. Positive type photosensitive paints can be used. The method for forming a positive photosensitive coating film on the substrate is not particularly limited, and known methods for forming a positive photosensitive coating film, such as electrodeposition method, spraying method, dip coating method, roll coating method, printing It can be formed by a method, a method of applying with a spin coater, or the like.

In general, as a positive type photosensitive coating material for forming a positive type photosensitive coating film, a resin having a coating film forming ability and photosensitivity (hereinafter referred to as a resin for positive type photosensitive coating material), and if necessary, Examples thereof include paints in which dyes, pigments and the like are dispersed or dissolved in organic solvents, water and the like. When a positive photosensitive coating material capable of electrodeposition is selected, part of the step (A) can be performed by electrodeposition. The positive photosensitive paint may contain a dye or a pigment.

Preferred examples of the positive type photosensitive coating resin include a resin having a quinonediazide group, a resin containing diazomeldrum acid or nitrobenzyl ester, and a resin composition containing these resins. . Specifically, for example, an acrylic resin, an epoxy resin, a urethane resin, a polybutadiene resin, etc., an amino group, an onium group such as sulfonium and a hydroxyl group were introduced, and further obtained by adding a quinonediazide sulfonic acid compound by an esterification reaction. Modified resin, formic acid, acetic acid,
A cationic resin composition having a quinonediazide group such as a resin solubilized or dispersed in water with an acid such as propionic acid or lactic acid or an acidic substance; acrylic resin, polyester resin, maleated oil resin, polybutadiene resin, epoxy resin A resin obtained by introducing a carboxyl group and a hydroxyl group into, etc. and further adding a quinonediazide sulfonic acid compound by an esterification reaction, solubilizes it in water with a basic substance such as triethylamine, diethylamine, dimethylethanolamine, and ammonia. Or an anionic resin composition having a quinonediazide group such as a dispersed resin; a composition comprising a reaction product of a resin having a film-forming function and a compound having a hydroxyl group, and a quinonediazidesulfonic acid derivative. Yes, especially from the viewpoint of process simplification and pollution prevention, Use of a resin capable of solubilizing or dispersing is preferred. The mixing ratio in the composition is
It can be arbitrarily selected depending on exposure conditions and development conditions.

In addition to these, it is possible to use a compound for a positive type photosensitive coating containing a compound having a group capable of forming an alkali or water-soluble group by an acid catalyst and a photo-acid generator as essential components.

The organic solvent used to disperse or dissolve each component such as the resin used in the positive type photosensitive paint may be any one which can dissolve or disperse the resin, and various glycol ethers, For example, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, propylene glycol monomethyl ether, propylene glycol monophenyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, ethylene glycol monoethylene ether acetate, propylene glycol monoethylene ether. Acetate and the like; Ketones such as acetone,
Methyl ethyl ketone, isobutyl ketone, cyclohexanone, isophorone, N-methylpyrrolidone and the like; ethers such as dibutyl ether, dioxane, tetrahydrofuran and the like; alcohols such as methoxybutanol, diacetone alcohol, butanol, octanol, isopropanol and the like; hydrocarbons , For example, toluene, xylene, cyclohexene, hexane, etc .; Esters, for example, ethyl acetate, butyl acetate, 2-methoxyethyl acetate, 2-ethoxyethyl acetate, 2-methoxypropyl acetate, ethyl benzoate, ethyl-2-ethoxy. Propionate, methyl lactate, ethyl lactate, methyl pyruvate, ethyl pyruvate, etc .; acid amides such as dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide Can be mentioned, it can be used alone or as mixtures in use. Further, the organic solvent, in order to facilitate the solubilization and dispersion of the resin to improve the stability of the electrodeposition bath, and further to obtain a smooth electrodeposition coating film, the cationic resin or anionic resin It can also be added when solubilizing or dispersing in water.

If necessary, the positive type photosensitive coating material may include
Dyes, pigments or mixtures thereof can be included. The hue of the dye or pigment can be appropriately selected according to the purpose. For example, in order to improve the resolution of the photosensitive coating, a light having a long wavelength with large diffraction is removed at the time of exposure.
It is desirable to incorporate a dye that absorbs light having a wavelength of up to 500 nm, such as oil yellow, or an ultraviolet absorber, such as trihydroxybenzophenone. Further, depending on the desired hue, two or more kinds of the above dyes or pigments may be mixed and used as long as the characteristics thereof are not impaired.

The use ratio of the dye and / or pigment is appropriately selected depending on the purpose, hue, type of dye or pigment used, film thickness of the positive photosensitive coating upon drying, and preferably positive photosensitive. The amount is preferably 0.01 to 10% by weight, and more preferably 0.1 to 5.0% by weight, based on the entire paint.

The positive photosensitive paint is prepared by using a resin for positive photosensitive paint, an organic solvent, water, and if necessary, a dye, a pigment, an acidic substance, a basic substance, a dispersion aid of a dye or a pigment, and a coating. A leveling agent for improving the smoothness of the film, a viscosity adjusting agent, various auxiliaries such as an antifoaming agent are mixed and sufficiently dispersed using a generally used sand mill, roll mill, disperser such as attritor, and the like. It can be obtained by a method of diluting to a concentration of.

The film thickness of the positive type photosensitive coating film formed by the positive type photosensitive coating material thus obtained is not particularly limited and can be appropriately selected according to the performance required for the color filter. Usually 0.3 to 20 when the coating film is dried
μm, preferably 0.5 to 15 μm, more preferably 1
It may be about 3 μm. The film thickness can be controlled by adjusting the electrodeposition conditions such as current, voltage, electrodeposition time, and liquid temperature when the film is formed by the electrodeposition method. It can be performed under the same conditions as the electrodeposition conditions of the coating composition.

Forming the positive photosensitive coating film on at least the transparent conductive region means that the positive photosensitive coating film is formed only on the transparent conductive region excluding the light shielding region.
Further, a positive type photosensitive coating film may be formed on both the transparent conductive region and the light shielding region.

In the first method of the present invention, the positive type photosensitive coating film is exposed from the back surface of the transparent substrate (the surface of the transparent substrate not coated with the positive type photosensitive coating film) through a photomask. The following step (hereinafter referred to as step (B)) is provided.
Further, in the second method, a step of forming a plurality of exposure regions having different exposure amounts in at least three stages on the positive photosensitive coating by exposure performed from the back surface of the transparent substrate through a photomask (hereinafter, referred to as step ( B1)).

In the steps (B) and (B1),
Since the photomask is placed on the opposite side of the surface coated with the positive type photosensitive coating and exposed to light, there is no contact between the photomask and the positive type photosensitive coating, and therefore the photomask is positive type. There is no problem of contamination by the photosensitive coating film. Therefore, if the step (B) or (B1) is adopted, it is possible to use, for example, a positive type photosensitive coating material which has tackiness or stains in the unexposed state.

The exposure in the step (B) or (B1) can be carried out by using a conventionally used apparatus, that is, an apparatus capable of generating a sufficiently large amount of ultraviolet rays.
For example, a high pressure mercury lamp, an ultra high pressure mercury lamp, a metal halide lamp, or the like can be used as the light source. A radiation source other than ultraviolet rays may be used if necessary. The exposure conditions can be appropriately selected according to the positive photosensitive coating used, the exposure device, the photomask, and the like. For example, in the case of ultraviolet irradiation, it can be appropriately selected from the irradiation intensity in the range of 10 to 1000 mJ / cm ² .

In the exposure of the step (B) or (B1), it is not always necessary to precisely expose only the range of the positive type photosensitive coating film of the transparent conductive region corresponding to each pixel, and for example, each pixel is exposed. The exposure may be performed to expose an area that is wider than the corresponding transparent conductive area and does not exceed the adjacent light-shielding area. Specifically, the back surface can be exposed through a photomask that irradiates the transparent conductive area and the light shielding area around the subpixel. By such an exposure method, for example, when the light-shielding region is conductive and a positive photosensitive coating film is formed on the light-shielding region, exposure from the surface causes precise alignment of the photomask and development. However, if the positive photosensitive coating film is not developed only on the part to be colored, the positive photosensitive coating film on the light-shielding area is developed, and the coloring paint adheres to the conductive light-shielding area during coloring. Occurs. However, by exposing from the back side, such a problem can be avoided, and since it is not always necessary to align the photomask with the transparent conductive area corresponding to each pixel with strict accuracy, the exposure operation can be performed in a short time. Can be done at.

In the step (B), for example, the exposure of a portion corresponding to the subpixel patterns of red, green, and blue colors required for the color filter is performed in one colored region, that is, one subpixel pattern. After the exposure, the developing and electrodeposition steps are performed in the next step (C), then the step (B) of exposing another subpixel pattern is performed, and the developing and electrodeposition operations in the step (C) are performed. It can be performed according to the number of sub-pixels (the number of colors of the colored region), but the number is not limited to this. For example, in step (B), after exposure of a portion corresponding to a plurality of subpixel patterns, in the next step (C), development and electrodeposition may be performed for each subpixel, or one subpixel. After the exposure, development and electrodeposition for forming the film, the remaining positive type photosensitive coating film is removed, the positive type photosensitive coating film is formed in the step (A), and the step (B) is performed again. May be. Furthermore, in the first method, the step (B
It is also possible to combine 1) and step (C).

On the other hand, in the step (B1), a plurality of exposure areas having different exposure amounts in at least three stages are formed on the positive photosensitive coating film by exposure from the back surface of the transparent substrate through a photomask. As such a method,
In the case of using a gradation mask, for example, a gradation mask having different light transmittances corresponding to red, green, and blue subpixel pattern portions and transparent outer frame portions in at least three stages is used, and A method of exposing a positive type photosensitive coating film to form a plurality of exposure areas having different exposure amounts in at least three steps, and exposing through a photomask having a specific pattern having two steps of different transmittances to obtain different patterns. The method of repeating the operation of changing the amount of exposure through the photomask and repeating the exposure again, the exposure is performed through a photomask having a specific pattern or the same photomask having two different light transmittances, and then the transparent substrate and Alternatively, any of a method of moving the photomask and re-exposure with different exposure amounts of at least two steps may be used. That is, any method can be used as long as different exposure areas can be formed in at least three stages. At this time, the portion with the smallest exposure amount may be the unexposed portion. By adopting a process of forming at least three different exposure areas in advance before development and electrodeposition, the number of expensive exposure devices can be reduced,
Moreover, since the number of operations of passing through the exposure device again after washing with water and drying accompanying development and electrodeposition can be reduced, work efficiency can be improved. Further, this step (B1) can be performed in combination with the step (B).

The light transmittance of the photomask means the ratio of the intensity of light rays used for exposure before and after passing through the mask. At this time, the number of steps of the difference in the exposure amount of the plurality of exposure areas may be at least three steps, and can be determined according to the number of kinds of the colored coating material to be used. It can be appropriately selected depending on the developing conditions. Usually, it is preferable to have a significant difference of 5% or more. Further, the movement of the photomask is to change the relative position of the photomask and the substrate,
For example, the substrate is fixed and the photomask is moved, or the photomask is fixed and the substrate is moved. Alternatively, the photomask is moved by moving both the substrate and the photomask.

In the case of the method of repeating the operation of moving the transparent substrate and / or the photomask and exposing with a different exposure amount, in the mask having a specific pattern, a portion through which light passes (hereinafter referred to as a pattern block) is It is preferable to use the pattern blocks that do not overlap each other after the necessary number of movements. Therefore, the distance between one pattern block and the adjacent pattern block must be at least wide enough so that the pattern blocks do not overlap at each exposure even if one pattern block moves by the number of movements.

The moving direction of the transparent substrate and / or the photomask is not particularly limited and may be any of front, rear, left and right as long as they are on the same plane, and the position and relative distance of the pattern block of the mask are the number of times of movement and the moving method. , The moving distance, etc.

In the exposure performed by moving the transparent substrate and / or the photomask, each exposure is performed with a light irradiation amount different from the light irradiation performed before that. The means for changing the light irradiation amount is not particularly limited, and for example, a method of changing the exposure time, a method of changing the distance of the light source,
Various methods such as a method of changing the output of the light source can be used. At this time, the difference in the light irradiation amount at the time of exposure so that the light irradiation amount is different can be appropriately selected according to the exposure condition and the developing condition described later. The relative difference in light irradiation amount is not particularly limited, but it is usually preferable that the difference is 5% or more.

In addition to the method of moving the transparent substrate and / or the photomask, two photomasks having different patterns can be replaced for each exposure and used.
The exposure method, the exposure amount, etc. can be the same as those described above.

In the method using at least two masks, the patterns of the masks may partially overlap with each other, and in this case, one light irradiation through each mask may be different or the same. good. When the light irradiation amount through each mask is the same, the exposure amount of the pattern overlapping portion is larger than that of the non-overlapping portion. The amount can be adjusted in at least three stages or more.

In the first method of the present invention, the above step (B)
The step of developing the positive type photosensitive coating film exposed in step (3) to expose the transparent conductive area, and then forming the colored area by electrocoating the colored electrodeposition coating composition (hereinafter referred to as step (C)). To have. In the second method, an operation of developing the positive photosensitive coating film to expose the transparent conductive region and then electrodepositing the colored electrodeposition coating composition on the exposed transparent conductive region,
The method further includes a step of forming a colored region by repeating the exposure region formed in the step (B1) in order from the largest exposure amount (hereinafter, referred to as step (C1)). In this step C1), in the development after the exposure area having the second largest exposure amount (including the exposure having the second largest exposure amount), if necessary, the entire surface of the substrate may be exposed from the back surface before the development. it can. At this time, the exposure amount of the entire surface exposure and the like can be appropriately selected.

In the steps (C) and (C1), the conditions for developing the positive type photosensitive coating film are as follows: the exposure amount of the portion to be removed, the solubility of the positive type photosensitive coating used in the developing solution, the developing solution. It may vary depending on the type and concentration of the resin, the developing temperature, the developing time, and the like, and the conditions suitable for the resin and the like used for preparing the photosensitive coating may be appropriately selected.

In particular, when the step (C1) is carried out, the portions of the exposure area having different exposure amounts are selectively developed and removed,
It is desirable to prepare necessary kinds of developers having different dissolving abilities for positive photosensitive paint so that the electrodeposition can be sequentially repeated. Further, in some cases, even if the number of kinds of the developing solution is less than the required number of kinds, selective development can be performed by a method of adjusting the developing time.

As the developing solution used in the steps (C) and (C1), an aqueous solution in which a basic substance is dissolved can be usually used. Specific examples of the basic substance include sodium carbonate, sodium hydrogen carbonate, sodium metasilicate, tetraalkylammonium hydroxide, sodium hydroxide, potassium hydroxide and the like. For example, an aqueous potassium hydroxide solution is used as a developing solution. When used in, the concentration of potassium hydroxide is usually 0.01 to 25% by weight, preferably 0.05 to 20% by weight, the developing temperature is usually 10 to 70 ° C, preferably 15 to 50 ° C, and the developing time is usually 2 It can be appropriately selected from the range of ˜600 seconds, preferably 30-300 seconds.

Further, in the developing solution, in addition to water, alcohols,
Organic solvents such as glycol ethers, ketones and chlorinated hydrocarbons can be used. In addition, a surfactant or an antifoaming agent may be added to these developers for improving wettability and defoaming, and an aqueous solution-type developing solution is used particularly in view of toxicity and working environment. Is preferred.

Development removes the exposed portions of the positive working photosensitive coating, resulting in the exposure of the transparent conductive layer underlying the positive working photosensitive coating. Then, the colored region is formed by electrodeposition coating the colored electrodeposition coating material on the exposed transparent conductive region which is the transparent conductive layer.

As the colored electrodeposition coating material for forming the colored region by the electrodeposition coating method, a conventionally known coloring electrodeposition coating material can be used. For example, a cationic or anionic resin is used as the resin component, and the coloring component is It is possible to use a paint or the like in which a dye and / or a pigment is added as described above, and the solution is dissolved or dispersed in water by neutralizing with an acidic or basic substance. In order to facilitate the dissolution or dispersion of the resin in the colored electrodeposition coating composition, further improve the stability of the electrodeposition bath, or to obtain a smooth electrodeposition coating film, alcohols and glycol ethers are used. Organic solvents such as, ketones, chlorinated hydrocarbons and the like can be appropriately added.

Specific examples of the cationic resin used as the resin component of the colored electrodeposition coating composition include acrylic resins, epoxy resins, urethane resins, polybutadiene resins, polyamide resins and the like, and onium groups such as amino groups and sulfonium groups. Examples of the resin having introduced therein are resins that are solubilized or dispersed in water with an acid such as formic acid, acetic acid, propionic acid, lactic acid or an acidic substance. As the anionic resin used as the resin component of the colored electrodeposition coating composition, for example, acrylic resin, polyester resin, maleated oil, polybutadiene resin, epoxy resin or the like having a carboxyl group introduced, triethylamine, diethylamine, dimethylethanolamine. , A resin solubilized or dispersed in water with a basic substance such as ammonia.

Furthermore, the colored electrodeposition coating composition may have photosensitivity. In addition, as the resin component of the colored electrodeposition coating composition, a thermosetting resin such as a mixture of acrylic resin and melamine resin may be used. When the colored electrodeposition coating material has photosensitivity or thermosetting property, the colored electrodeposition coating material is cured by appropriate light irradiation or heating after electrodeposition.

In the steps (C) and (C1), the colored electrodeposition paint is different in type, hue, color density, and
It is desirable to use different hues of light and shade, but if there are more than the required number of colors with different exposures, the same hue can be used redundantly.

The dye and / or pigment used in the colored electrodeposition coating composition is selected according to the intended hue, but the transparency of the resulting coating film, the stability of the coating composition and coating film, the electrodeposition characteristics,
It is desirable to select a film that does not cause a problem with respect to the durability of the coating film. Depending on the desired hue, dyes,
Two or more kinds of pigments can be mixed and used as long as the properties are not impaired.

It is desirable to select, as the dye and / or pigment, one that does not impair the stability of the coating, the electrodeposition characteristics, the durability of the coating film, etc., if necessary. From this point, the dye is preferably an oil-soluble or dispersible dye, and specific examples thereof include azo type, anthraquinone type, benzodifuranone type and condensed methine type dyes. As a pigment,
For example, organic pigments such as azo chelate type, quinacridone type, phthalocyanine type, isoindolinone type, anthraquinone type, thioindigo type, yellow lead, iron oxide, chrome vermillion, chrome green, ultramarine blue, navy blue, cobalt blue, cobalt green, emerald Inorganic pigments such as green can be mentioned. The dyes and / or pigments can be appropriately selected by referring to materials such as "COLOR INDEX".

The above-mentioned colored electrodeposition coating composition is prepared by using a resin, a dye and / or a pigment, an acidic substance, a basic substance, if necessary, an organic solvent, a dispersion aid for the dye or the pigment, and leveling for improving the smoothness of the coating film. Agents, viscosity modifiers, defoamers, and various other auxiliaries, etc. are mixed and sufficiently dispersed using a commonly used disperser such as a sand mill, roll mill, or attritor, and then a predetermined concentration with water. , Preferably a solid content of about 1
It can be carried out by a method of diluting to 25 wt%, particularly preferably 3 to 15 wt% to obtain a coating suitable for electrodeposition. The colored electrodeposition coating composition thus obtained forms a colored layer by electrodeposition coating on the transparent conductive region. The thickness of the colored layer is not particularly limited and can be appropriately selected according to the performance required for the color filter, but it is usually 0.3 to 5 μm, preferably 1 to 3 μm when dried.

The conditions for the electrodeposition coating are appropriately selected depending on the kind of the colored electrodeposition coating used and the thickness of the intended colored layer, but the voltage is usually 2 to 500 V, preferably 4 to 3 V.
A direct current of 00 V is preferable, and the electrodeposition time is usually 5 to
300 seconds, preferably 10-200 seconds, liquid temperature is usually 10
It is desirable that the temperature is ˜35 ° C., preferably 15˜30 ° C. At this time, stop the energization when the electrodeposition time to obtain the desired film thickness has elapsed, remove the substrate from the electrodeposition bath, thoroughly wash the electrodeposition bath solution adhering to the substrate with water, etc., and then dry it appropriately. By this, a colored layer can be formed.

The above-mentioned drying conditions after electrodeposition can be appropriately selected depending on the conditions of the subsequent steps, etc., but it is usually required that the surface moisture can be dried, for example, 150 ° C. or less, preferably 60 ° C. to 120 ° C. It is desirable to dry at 1 ° C. for usually 1 minute to 1 hour, preferably 5 to 30 minutes.

The colored layer formed by electrodeposition may be further heat-cured if necessary, such as when the colored electrodeposition coating composition is thermosetting, to further improve weather resistance and chemical resistance. When such heat curing is performed, for example, the temperature is usually 100 to 270 ° C., preferably 120 to 25.
It may be carried out under conditions of 0 ° C., 5 minutes to 1 hour, preferably 15 to 40 minutes.

In the method for producing a color filter of the present invention, in the case of the first method, the steps (A), (B),
When the step (C) is the second method, on the other hand, the step (A), the step (B1) and the step (C1) may be included, and the order and the number of steps can be appropriately selected. . Further, if the essential steps in each of the above methods are provided, different steps in other methods can be performed in combination.

[0055]

EXAMPLES The present invention will be described in more detail with reference to production examples and examples, but the present invention is not limited thereto.

[0056]

[Production Example 1] Color coatings (R-1), (G-1), (B-1) and black coatings
Production of (BK-1) An acrylic resin (manufactured by Toagosei Co., Ltd., trade name "Aron S-4020") was neutralized with triethylamine until the pH reached about 8, and deionized water was added thereto. An aqueous resin solution (S) was prepared. Next, carbon black, azo metal salt red pigment, phthalocyanine green, and phthalocyanine blue were added to the resin aqueous solution (S) under stirring to prepare black, red, green, and blue pigment dispersions, respectively.

In addition to these, melamine resin (manufactured by Sumitomo Chemical Co., Ltd., trade name "M-5" is added to the acrylic resin.
6 ") was mixed with triethyleneamine to adjust the pH to 8
It neutralized until it became and the deionized water was added to this, and the resin aqueous solution (T) was created.

By adding an aqueous resin solution (T) to the pigment dispersions of the respective colors, the colored electrodeposition paints (R-1), (G-1) and (B-1) having the compositions shown in Table 1 were obtained. And black paint
(BK-1) was obtained. The obtained coating is thermosetting,
It is also an anionic colored electrodeposition paint.

[0059]

[Table 1]

[0060]

[Manufacturing Example 2] Manufacturing Method of Original Plate 1 A 0.7-mm-thick Pyrex glass substrate having a transparent conductive film (ITO film) with a film thickness of 100 nm on its surface was used as a positive photoresist (trade name "OFRR" manufactured by Tokyo Ohka Co., Ltd.). -8
00 ”) was applied by a spin coater and dried at 80 ° C. for 10 minutes to form a positive photosensitive coating film having a film thickness of 2.5 μm.

A UV exposure apparatus (manufactured by Oak Manufacturing Co., Ltd., trade name "JL-3300") having a high-pressure mercury lamp through the mask shown in FIG. 1 (mask having a pattern corresponding to the portion 1 corresponding to the light shielding layer). ), 100m
After irradiation with UV of J / cm ² , development was carried out with a tetramethylammonium hydroxide aqueous solution having a concentration of 2.4% by weight. As a result, the positive photosensitive coating film in the exposed region, that is, the portion corresponding to the portion 1 where the light transmittance of the mask was 100% was selectively removed, and the transparent conductive film (ITO film) was exposed.

After washing with water and drying, chromium and chromium oxide as a light-shielding film were vapor-deposited so as to have a film thickness of 100 nm, and the remaining positive photosensitive coating film was removed. Next, this substrate is washed with ion-exchanged water and then dried at 120 ° C. for 10 minutes, and a transparent substrate having a 100 nm-thick chromium oxide / chrome light-shielding film and a 100 nm-thick ITO transparent conductive layer on its surface (hereinafter referred to as “ Original plate 1 ”) was manufactured.

[0063]

[Manufacture Example 3] Manufacture of original plate 2 A 0.7 mm-thick Pyrex glass substrate having a transparent conductive film (ITO film) having a film thickness of 100 nm on its surface was used as a positive photoresist (trade name "OFRR-" manufactured by Tokyo Ohka Co., Ltd.). 8
00 ”) was applied by a spin coater and dried at 80 ° C. for 10 minutes to form a positive photosensitive coating film having a film thickness of 2.5 μm.

A UV exposure apparatus (manufactured by Oak Manufacturing Co., Ltd., trade name "JL-3300") having a high-pressure mercury lamp through the mask shown in FIG. 1 (mask having a pattern corresponding to the portion 1 corresponding to the light shielding layer). ), 100m
After irradiation with UV of J / cm ² , development was carried out with a tetramethylammonium hydroxide aqueous solution having a concentration of 2.4% by weight. As a result, the positive photosensitive coating film in the exposed region, that is, the portion corresponding to the portion 1 where the light transmittance of the mask was 100% was selectively removed, and the transparent conductive film (ITO film) was exposed.

After washing with water and drying, the obtained transparent substrate was used as an anode and electrodeposition was carried out for 20 seconds under conditions of a DC voltage of 28 V and 25 ° C. to form a black paint having a film thickness of 1.8 μm.

Then, the remaining positive type photosensitive coating film is removed, the substrate is washed with ion-exchanged water, and then at 120 ° C. for 1 hour.
After drying for 0 minutes, the black electrodeposition coating film was further heat-cured at 180 ° C. for 30 minutes to produce a transparent substrate (hereinafter referred to as “original plate 2”) having a light-shielding film and a transparent conductive layer on the surface.

[0067]

Example 1 A positive photoresist (manufactured by Tokyo Ohka Co., Ltd., trade name "OFRR-80") was applied to the original plate 1 produced in Production Example 2.
0 ") was applied by a spin coater and dried at 80 ° C. for 10 minutes to form a positive photosensitive coating film having a film thickness of 2.5 μm on the surface.

Then, through the mask shown in FIG. 2 (this is a mask having a pattern corresponding to the portion 3 corresponding to the colored layer of the first color), from the back surface of the substrate on which the photosensitive coating film is not formed, UV backside exposure device using an ultra-high pressure mercury lamp (manufactured by Toshiba Lighting & Technology Corp., trade name "91A-1"
3127C ”), and irradiated with ultraviolet rays of 100 mJ / cm ² , followed by development with a tetramethylammonium hydroxide aqueous solution having a concentration of 2.4% by weight. As a result, the light transmittance of the exposed area, that is, the mask in FIG.
The positive type photosensitive coating film in the portion corresponding to 0% portion 3 is selectively removed, and the transparent conductive film (ITO film) in that portion is removed.
Was exposed.

The area of the portion 3 in FIG. 2 is as shown in FIG.
The area is wider than the area of the portion 2 and does not exceed the area corresponding to the light shielding layer in the periphery. Therefore, the alignment of the mask in FIG. 2 does not need to be precise, and it can be performed easily and easily. The alignment of the mask in the following examples was similar.

Next, after washing with water and drying, the original plate 1 was used as an anode, and a stainless steel beaker containing the first color (red) colored paint (R-1) was used as a cathode, and a DC voltage of 3 was applied.
It was electrodeposited at 0 V and 20 ° C. for 18 seconds, washed with ion-exchanged water, and then dried at 120 ° C. for 10 minutes. As a result, a red area could be formed in the exposed transparent conductive area.

Next, using the mask shown in FIG. 2, alignment is performed so that the pattern portion 3 corresponds to the portion corresponding to the second color (green) colored layer, and the back surface is passed through the mask in the same manner as the previous time. Exposed. Next, development was performed with a tetramethylammonium hydroxide aqueous solution having a concentration of 2.4% by weight.
As a result, the light transmittance of the exposed area, that is, the mask is 10
The positive type photosensitive coating film in the portion corresponding to 0% portion 3 was selectively removed, and the transparent conductive film (ITO film) was exposed. Further, the second color was electrodeposited in the same manner as the first color. At this time, the second color region could be formed without any change being observed in the first color electrodeposition coating film formed previously.

Similarly to the second color, the third color (blue) colored layer was also formed by backside exposure, development and electrodeposition. No change was observed in the first-color and second-color coloring layers formed earlier, and the third-color coloring layer was formed.

The entire surface of the original plate 1 is irradiated with ultraviolet rays of 200 mJ / cm ² , and the positive photosensitive coating film remaining on the surface is removed with a 3.5% by weight aqueous solution of tetramethylammonium hydroxide, followed by washing with water and drying. I did. By this operation, the transparent conductive layer as the outer frame portion of the color filter was exposed.

When the colored layer was cured by heating at 180 ° C. for 30 minutes, the film thickness was 2 μm ±
Having a colored layer of 0.1 μm, a light-shielding layer and a transparent outer frame,
A uniform and excellent color filter was obtained.

[0075]

[Example 2] A positive photoresist (manufactured by Tokyo Ohka Co., Ltd., trade name "OFRR-80") was applied to the original plate 1 produced in Production Example 2.
0 ") was applied by a spin coater and dried at 80 ° C. for 10 minutes to form a positive photosensitive coating film having a film thickness of 2.5 μm on the surface.

Next, through the mask shown in FIG. 2 (this is a mask having a pattern corresponding to the portion 3 corresponding to the colored layer of the first color), from the back surface of the substrate on which the photosensitive coating film is not formed, UV backside exposure device with ultra high pressure mercury lamp (manufactured by Toshiba Lighting & Technology Corp., trade name "91A-1"
3127C ”), and irradiated with ultraviolet rays of 100 mJ / cm ² , followed by development with a tetramethylammonium hydroxide aqueous solution having a concentration of 2.4% by weight. As a result, the light transmittance of the exposed area, that is, the mask in FIG.
The positive type photosensitive coating film in the portion corresponding to 0% portion 3 is selectively removed, and the transparent conductive film (ITO film) in that portion is removed.
Was exposed.

Next, after washing with water and drying, the original plate 1 was used as an anode, a stainless steel beaker containing the first color (red) colored paint (R-1) was used as a cathode, and a DC voltage of 3 was applied.
It was electrodeposited at 0 V and 20 ° C. for 18 seconds, washed with ion-exchanged water, and then dried at 120 ° C. for 10 minutes.

Next, a mask shown in FIG. 3 (this is a portion 5 corresponding to the colored layer of the second color and a portion 6 corresponding to the third color).
Is a mask having a pattern corresponding to. UV backside exposure apparatus (from Co., Ltd.) having an ultra-high pressure mercury lamp from the backside of the substrate through the order of high light transmittance; part 5> part 6> part 7)
Product made by Toshiba Lighting & Technology, product name "91A-13127C")
Was irradiated with ultraviolet rays of 100 mJ / cm ² and then developed with an aqueous tetramethylammonium hydroxide solution having a concentration of 2.4% by weight. As a result, the positive photosensitive coating film in the area having the largest exposure amount, that is, the portion corresponding to the portion 5 having the highest light transmittance of the mask is selectively removed,
The transparent conductive film (ITO film) was exposed.

After washing with water and drying, the original plate 1 was used as an anode, and a stainless steel beaker containing the second color (green) colored paint (G-1) was used as a cathode, and a DC voltage of 30 V was used.
It was electrodeposited for 18 seconds under the condition of 20 ° C. The obtained original plate 1 was washed with ion-exchanged water and then dried at 120 ° C. for 10 minutes,
A second color (green) colored layer was formed.

Next, from the back surface to the entire substrate, 20 mJ / cm
After irradiating with the ultraviolet ray of ² , it was developed with a 3.5% by weight aqueous solution of tetramethylammonium hydroxide. As a result, the positive photosensitive coating film in the exposed region, that is, the portion corresponding to the portion 6 having the second highest light transmittance of the mask was selectively removed, and the transparent conductive film (ITO film) was exposed.

Then, after washing with water and drying, a colored paint (G-1)
In the same manner as in the electrodeposition coating of No. 1, after the third color (blue) colored paint (B-1) was electrodeposited and washed with ion-exchanged water, 12
It was dried at 0 ° C. for 10 minutes. At this time, no change was observed in the first and second color electrodeposition coating films formed previously,
A third color was formed.

The entire surface of the original plate 1 was irradiated with ultraviolet rays of 200 mJ / cm ² , the remaining positive photosensitive film was removed with a 3.5% by weight aqueous solution of tetramethylammonium hydroxide, washed with water and dried. At this time, the transparent conductive layer in the outer frame portion of the color filter was exposed.

When the colored layer was cured by heating at 180 ° C. for 30 minutes, the film thickness was 2 μm ±
Having a colored layer of 0.1 μm, a light-shielding layer and a transparent outer frame,
A uniform and excellent color filter was obtained.

[0084]

Example 3 A positive photoresist (manufactured by Tokyo Ohka Co., Ltd., trade name “OFRR-80”) was added to the original plate 2 produced in Production Example 3.
0 ") was applied by a spin coater and dried at 80 ° C. for 10 minutes to form a positive photosensitive coating film having a film thickness of 2.5 μm on the surface.

Then, through the mask shown in FIG. 2 (this is a mask having a pattern corresponding to the portion 3 corresponding to the colored layer of the first color), from the back surface of the substrate on which the photosensitive coating film is not formed, UV backside exposure device with ultra high pressure mercury lamp (manufactured by Toshiba Lighting & Technology Corp., trade name "91A-1"
3127C ”), and irradiated with ultraviolet rays of 100 mJ / cm ² , followed by development with a tetramethylammonium hydroxide aqueous solution having a concentration of 2.4% by weight. As a result, the light transmittance of the exposed area, that is, the mask in FIG.
The positive type photosensitive coating film in the portion corresponding to 0% portion 3 is selectively removed, and the transparent conductive film (ITO film) in that portion is removed.
Was exposed. At this time, no change was observed in the black light shielding layer of the original plate 2.

After washing with water and drying, the original plate 1 is used as an anode, and the first color (red) colored paint (R-1) is electrodeposited,
After washing with ion-exchanged water, it was dried at 120 ° C. for 10 minutes. At this time, no change was observed in the black light shielding layer formed previously, and the first colored layer was formed.

The entire surface of the original plate 2 was irradiated with ultraviolet rays of 200 mJ / cm ² , the residual positive type photosensitive coating film was removed with a 3.5% by weight aqueous solution of tetramethylammonium hydroxide, washed with water and dried. Further, a positive photoresist (manufactured by Tokyo Ohka Co., Ltd., product name “OFRR-800”) is applied to the original plate 2.
Was applied with a spin coater and dried at 80 ° C. for 10 minutes,
A positive photosensitive coating film having a thickness of 2.5 μm was formed.

Next, the mask shown in FIG. 4 (this mask is
UV backside exposure device (manufactured by Toshiba Lighting & Technology Corp., trade name "91A-13" having an ultra-high pressure mercury lamp from the backside of the substrate through a mask having a sufficient length in the moving direction).
127 C ”) was used to irradiate ultraviolet rays of 100 mJ / cm ² (hereinafter referred to as“ first exposure ”). Next, it was moved by the direction and distance shown in FIG. 4 and irradiated with ultraviolet rays of 75 mJ / cm ² (hereinafter referred to as “second exposure”).

Next, it was developed with an aqueous solution of tetramethylammonium hydroxide having a concentration of 2.4% by weight. As a result, the positive type photosensitive coating film in the area having the largest exposure amount, that is, the portion exposed by the first exposure was selectively formed. And the transparent conductive film (I
The TO film) was exposed.

After washing with water and drying, the original plate 2 was used as an anode, and a stainless steel beaker containing the second color (green) colored paint (G-1) was used as a cathode, and a DC voltage of 30 V,
It was electrodeposited for 18 seconds under the condition of 25 ° C. The obtained original plate 2 was washed with ion-exchanged water and then dried at 120 ° C. for 10 minutes,
A second color (green) colored layer was formed.

Next, from the back surface to the entire substrate, 20 mJ / cm
After irradiating with the ultraviolet ray of ² , it was developed with a 3.5% by weight aqueous solution of tetramethylammonium hydroxide. As a result, the positive type photosensitive coating film in the region having the second largest exposure amount, that is, the portion exposed by the second exposure is selectively developed and removed,
The transparent conductive film (ITO film) was exposed.

After washing with water and drying, the third color (blue) colored paint (B-
1) was electrodeposited, washed with ion-exchanged water, and then dried at 120 ° C. for 10 minutes. At this time, no change was observed in the first-color and second-color electrodeposition coating films formed previously, and the third color was formed.

The entire surface of the original plate 2 was irradiated with ultraviolet rays of 200 mJ / cm ² , the residual positive photosensitive coating film was removed with a 3.5 wt% aqueous solution of tetramethylammonium hydroxide, washed with water and dried. At this time, the transparent conductive layer in the outer frame portion of the color filter was exposed.

When the colored layer was cured by heating at 180 ° C. for 30 minutes, the film thickness was 2 μm ±
Having a colored layer of 0.1 μm, a light-shielding layer and a transparent outer frame,
A uniform and excellent color filter was obtained.

[0095]

In the method of manufacturing a color filter of the present invention, since the back side of the substrate is exposed, the positive type photosensitive coating film and the photomask are not in contact with each other, and the photomask is the positive type photosensitive coating film. Not polluted by. Further, by adopting a step of forming a plurality of different exposure areas in at least three levels of exposure amount on the positive type photosensitive coating film,
The required number of expensive exposure machines can be reduced, and this is an inexpensive method. Furthermore, by using a photomask having a pattern corresponding to each pixel, which is wider than the transparent conductive region of the portion corresponding to each pixel and does not exceed the adjacent light-shielding region, as a photomask for exposure. It is not necessary to align the photomask, which requires strict accuracy. Since accurate exposure is performed in a self-aligning manner by utilizing the light-shielding area, there is little risk that the positive photosensitive coating film on the light-shielding area is exposed and developed even when the light-shielding area has conductivity. Therefore, it is possible to prevent the colored layer from being electrodeposited on the light-shielding region and also to prevent the positive photosensitive coating film from remaining at the boundary between each pixel and the light-shielding region.

[Brief description of drawings]

FIG. 1 is a schematic view of a photomask having a pattern in which the light transmittance used in Examples is different in two steps.

FIG. 2 is a schematic view of a photomask having a pattern having two different light transmittances used in the examples.

FIG. 3 is a schematic view of a photomask used in an example and having a pattern in which the light transmittance is different in three stages.

FIG. 4 is a schematic view of a photomask used in an example, having a pattern in which light transmittance is different in two stages and having a sufficient distance in a movable direction.

[Explanation of symbols]

 1, 3, 5, 8: a portion having a light transmittance of 100%, 2, 4, 7, 9: a portion having a light transmittance of 0%, 6: a portion having a light transmittance of 70%

Claims (3)

[Claims] 1. A method of manufacturing a color filter, comprising the following steps (A) to (C). (A) a step of forming a positive photosensitive coating film on at least the transparent conductive area of a transparent substrate having a light-shielding area and a transparent conductive area corresponding to each pixel on the surface, (B) from the back surface of the transparent substrate Exposing the positive photosensitive coating through a photomask, and (C) developing the positive photosensitive coating exposed in the step (B) to expose transparent conductive regions and then coloring A step of forming colored regions by electrodeposition coating an electrodeposition coating. 2. A method of manufacturing a color filter, comprising the following steps (A), (B1) and (C1). (A) a step of forming a positive photosensitive coating film on at least the transparent conductive area of a transparent substrate having a light-shielding area and a transparent conductive area corresponding to each pixel on the surface, (B1) from the back surface of the transparent substrate A step of forming a plurality of exposed regions having different exposure amounts in at least three stages on the positive photosensitive coating by exposure performed through a photomask, (C1) developing the positive photosensitive coating to form a transparent conductive region Are exposed, and then the electrodeposition coating of a colored electrodeposition coating composition is applied to the exposed transparent conductive region in order from the larger exposure amount of the exposed region formed in the step (B1) to sequentially form the colored region. Forming process. 3. The exposure of the positive type photosensitive coating film, which is performed from the back surface of the transparent substrate through a photomask, is wider than the transparent conductive area corresponding to each pixel and does not exceed an adjacent light shielding area. The exposure is an exposure.
Or the method for producing the color filter according to item 2.