JPH04218001A - Color filter - Google Patents

Abstract

PURPOSE:To obtain a color filter superior in colored density. CONSTITUTION:The color filter is obtained by dyeing a film formed on a substrate with a dyeing bath containing ureas and/or an inorganic salt.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter. More specifically, the present invention relates to a color filter that can be used in solid-state image sensors, color liquid crystal display devices, and the like.

0002

[Prior Art] Color filters are manufactured using a dyeing method, which consists of a synthetic material having transparent cationic groups in the form of a striped or mosaic thin film (called a pattern) on the surface of a substrate such as glass or silicon wafer. The basic principle is to provide a resin film or a protein-based natural polymeric material film such as gelatin, casein, or glue as a colored film, and then dye (color) this using a dye. The following three methods are known as specific manufacturing processes for color filters.

(1) After a film to be colored is provided on the surface of the substrate, it is exposed to light through a mask and developed, and the resulting pattern is dyed to form a colored layer. Next, a non-colored protective coating film is provided over the entire surface, and a second colored film is provided thereon by the same procedure as described above. Thereafter, colored layers are sequentially laminated as necessary. (2) After forming a film to be colored on the surface of the substrate, it is exposed to light through a mask, developed, and the resulting pattern is dyed to form a color. After that, the dye is fixed and resisted with tannic acid, etc. Rub. A second coating to be colored is provided by a similar operation. Thereafter, if necessary, a colored layer is formed on the same substrate surface. (3) First, a film to be colored (a film to be colored) is provided on the surface of the substrate. After providing a positive resist layer thereon, the colored film exposed in a pattern is dyed by exposure and development through a mask, and then the positive resist layer is peeled off to form a colored portion. The operations after forming the positive resist layer are repeated to dye the same colored film in a plurality of colors in a desired pattern.

[0004] Color filters manufactured by the above process usually have three primary colors, R (red) and G (
green), B (blue) or three complementary primary colors Y (yellow), M
(magenta) and C (cyan). The most important property required of a color filter is its optical property, and the spectral properties of each colored layer greatly control the value of the final product. By the way, gelatin
Since protein-based natural polymer substances such as casein and glue have cationic groups, they can be dyed (colored) with water-soluble anionic dyes. In addition, when using a photocurable synthetic resin base material instead of these, by retaining cationic groups in the resin component, it can be dyed with water-soluble anionic dyes in the same way as protein-based natural polymer substances. Become so.

[0005] In the method for producing a color filter using the dyeing method described above, each film must be dyed to a density that satisfies predetermined optical properties as a color filter.
The concentration depends on the thickness of the patterned film to be dyed, but recently there has been a tendency to reduce the thickness from the viewpoint of electrical characteristics, viewing angle, etc. In order to maintain sufficient performance as a color filter even if the dyed pattern film becomes thinner, it is necessary to dye the film at a high concentration.

Factors governing the color density of the patterned film to be dyed are the dye-receiving ability of the photosensitive resin used, the dyeing power (affinity) of the dye used for the photosensitive resin, and the dyeing conditions employed. . The dye-receiving ability of a photosensitive resin is determined based on the balance with the other main characteristics of a color filter, such as film-forming properties, sensitivity to irradiation light, resolution, and developability, and is unique to photosensitive resins. Yes, it cannot be changed arbitrarily. In addition, the dye's ability to dye photosensitive resins is mainly controlled by the molecular structure of the dye, but the molecular structure is also a factor that controls color characteristics (spectral characteristics) and durability (heat resistance, light resistance, etc.), and overall It is usually difficult to change it arbitrarily as it is determined based on the objective balance.

A factor that can be changed arbitrarily is the dyeing conditions, and generally, by adopting conditions of high temperature, long time, and low pH (increasing the acidity of the bath), the amount of dye adhering to the photosensitive resin increases. Although color density can also be increased, under such conditions there is a risk of problems such as film roughening, peeling of the film from the substrate, and deterioration of resolution due to swelling. It has also been proposed to add a dyeability improver to the dye solution (dyebath) for the purpose of increasing the amount of dyeing. For example, when dyeing nitrogen-containing fibers with acid dyes, benzyl alcohol or butanol is A solvent-assisted dyeing method in which a poorly soluble organic solvent is added is known. Although this method has been shown to produce a deep color effect, it is not practical due to the deterioration of film properties due to the use of organic solvents, the difficulty in handling and processing the dye solution after dyeing, and the problem of odor. put on.

[0008]

Problems to be Solved by the Invention When dyeing a patterned film for producing a color filter, it is desired to establish a method for obtaining a patterned film dyed in a deep color using a simple method.

[0009]

[Means for Solving the Problems] The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, they have arrived at the present invention. That is, the present invention provides a color filter obtained by dyeing a film placed on a substrate in the presence of ureas and/or inorganic salts.

The present invention will be explained in detail. First, protein-based natural polymeric substances such as gelatin, casein, and glue for forming the film to be colored in the present invention will be explained. Gelatin is an animal protein made by boiling collagen with water to irreversibly make it water-soluble. Gelatin is extracted from animal bones, skin, tendons, etc. by boiling it with water. Casein is a phosphorus protein that is the main component of milk. A dichromate such as ammonium dichromate is added to an aqueous solution of these natural proteins, and after it is applied uniformly onto a substrate such as glass by spin coating or roller coating, the coated layer is cured by irradiation with ultraviolet rays. , then e.g. 10-60°C, 1-
A patterned cured film is obtained by processing (developing) in water or the like for 10 minutes.

[0011] Further, examples of synthetic resins having a cationic group as the coloring material used in the present invention include the following. That is, a photoreactive resin composition consisting of an anionic dyeable polymer, a compound having two or more photoreactable unsaturated groups in one molecule, a diazide photosensitive compound, and optionally an organic solvent is used to produce a group. After being applied to the surface of a material, it is irradiated with active light such as ultraviolet rays to cause a reaction and form a film. In this case, the anionic dye-dyeable polymer includes a nitrogen-containing monomer such as (N,N-dimethylamino)ethyl acrylate, (N,N-diethylamino)ethyl methacrylate, and a hydrophilic monomer such as hydroxyethyl acrylate or dimethylamino acrylamide. It is obtained by polymerizing a monomer with a hydrophobic monomer such as methyl acrylate or butyl methacrylate. Examples of compounds having two or more photoreactive unsaturated groups in one molecule include ethylene glycol diacrylate and diethylene glycol diacrylate. Further, as the diazide photosensitive compound, for example, 4,4'-
Examples include diazidochalcone, 2,6-bis(4'-azidobenzal)cyclohexanone, and the like. Examples of organic solvents that can be used to dilute the resin composition include methyl cellosolve, methyl ethyl ketone, and toluene, which may be used alone or in combination. Such a photoreactive resin composition is applied to the surface of a substrate and irradiated with active light such as ultraviolet rays by a conventional method to obtain a cured film.

Examples of the photocurable anionic dye-dyeable synthetic resin are not limited to the above examples, but include polymers having a photoreactive unsaturated group and a quaternary ammonium base in the side chain. A photoreactive resin composition consisting of a photopolymerization initiator and a solvent as main components, or chalcone, cinnamic acid,
It may also be a resin composition in which a cationic group-containing polymer in which a photocrosslinking group such as an azide or stilbazole group has been introduced into the polymer is dissolved in water or an organic solvent.

For dyeing (coloring) the cured coating using an anionic dye, for example, a dipping method or a printing method is used, and a dipping method using an aqueous solution is particularly convenient. In this case, the substrate (substrate) provided with the above film is usually placed in a dye bath of 10 to 100°C in which 0.1 to 30 g, preferably 1 to 10 g of the dye is dissolved in 1 liter of water for 10 seconds or more.
After soaking for about 0 minutes, take it out, wash it with water, and dry it. The colored film thus obtained exhibits favorable optical properties as a color filter. A method for forming a non-staining protective film on a colored film is to use a negative photoresist (for example, a resin composition obtained by adding a photo-crosslinking agent such as a diazo compound to an acrylic or polyvinyl alcohol-based polymer, or A method in which a photocrosslinking group such as chalcone or silicon film is introduced into an acrylic or polyvinyl alcohol polymer in advance) is dissolved in water or an organic solvent, applied by spin coating, and cured by irradiation with ultraviolet rays. Adopted.

In the present invention, the substrate (substrate) on which the film to be dyed is provided may be a glass, plastic sheet or silicon wafer, etc., which may be pretreated with a silane coupling agent or the like or provided with a flattening layer, if necessary. available for use above. In addition, water or a hydrophilic solvent (methanol,
ethanol, isopropanol, methyl cellosolve, etc.)
Alternatively, acidic dyes, direct dyes, and reactive dyes that can be dissolved in a mixed solvent of both are used, and commercially available dyes are used as they are or preferably after being purified. Among these, acid dyes are particularly preferred.

[0015] The dye bath for dyeing is prepared using water, and the concentration of dye in the dye bath is 0.1 to 5.0%.
Preferably, it is 0.1 to 2%, and the amount of urea added to the dye bath is 1 to 30%, preferably 5 to 30%.
It is 20%. Also, the amount of inorganic salt used is 0 for the dye bath.
．． 5-5%, preferably 0.5-3%. These ureas and inorganic salts may be used alone or in combination, and they are thought to act as a deep dyeing agent. The pH of the dye bath is preferably adjusted to 3 to 7 with an acid, but the optimum pH depends on the dye used and the dyeable resin to be dyed, and is determined by the type thereof. Specific examples of ureas include urea, thiourea, ethylene urea, tetramethyl urea, etc. Specific examples of inorganic salts include ammonium chloride, ammonium sulfate, sodium sulfate, phosphate, sodium chloride, etc. It is not limited to these. Furthermore, preferred inorganic salts include ammonium salts that do not contain metal ions. When preparing a dyebath, water is usually used, but if desired, a water-soluble solvent such as methanol, ethanol, isopropanol, methyl cellosolve, etc. may be used in combination.

The dye bath is prepared by adding ureas and/or inorganic salts to an aqueous solution of the dye, or by preparing a powder composition obtained by mixing ureas and/or inorganic salts with the dye in advance. It may also be prepared by adding an aqueous solution composition. The dyeing temperature is usually 20 to 80°C, preferably 40 to 70°C. In addition, the dyeing time is usually 3 to 60 minutes, preferably 5 to 3 minutes.
It is 0 minutes.

According to the dyeing method of the present invention, a dyeable film provided on a substrate can be dyed in a deep color.

【Example】

The present invention will be explained in more detail with reference to Examples.

Example 1 A photosensitive solution prepared by mixing 10 parts of FUR-12 (casein manufactured by Fuji Pharmaceutical Co., Ltd.) with 10 parts of a 7.5% aqueous solution of ammonium dichromate was applied onto optical glass by spin coating. , was applied to a film thickness of 1 μm, dried at 70° C. for 30 minutes, and then exposed to light through a prescribed mask. Subsequently, the substrate was immersed in water for 3 minutes, and after development, a dyeable resin pattern film was obtained on the substrate. Next, this patterned film was coated with 0.5 phthalocyanine dye represented by formula (1).
1 part of urea in an aqueous solution (1005 parts) consisting of 100 parts of water
pH 5 in a dyebath containing 0 parts of ammonium chloride and 2 parts of ammonium chloride.
．． The sample was dyed at 70° C. for 20 minutes, washed with water and dried to obtain a green colored pattern. The dyeing density (absorbance) of this colored pattern film is 0.89 (680 nm) on the cyan side and 1 on the yellow side.
．． 14 (435 nm), and the maximum transmittance is 78% (5
30 nm).

[0019]

[Chemical formula 1]

(In formula (1), Pc represents a phthalocyanine residue, and X represents 1 to 3, respectively.)

[0021]
Example 2 A dyeable resin pattern film obtained in the same manner as in Example 1 was dissolved in a mixture of 0.5 parts of the dye of formula (1), 10 parts of tetramethylurea, and 2 parts of ammonium chloride in 100 parts of water. It was dyed in the obtained dye bath at pH 5.0 and 70° C. for 20 minutes, washed with water and dried to obtain a green colored pattern. The dyeing density (absorbance) of this colored pattern film is 1.0 on the cyan side.
22 (680nm), 1.62 (435nm) on the yellow side
, the maximum transmittance was 68% (530 nm).

Example 3 CFR-633L on optical glass
(Acrylic anion dye dyeable photosensitive resin composition manufactured by Nippon Kayaku Co., Ltd.) was coated by spin coating,
After drying at 80°C for 30 minutes, UV irradiation was performed for 5 seconds at a surface illuminance of 8 mw/cm2 through a patterned mask, and Emulgen 913 (manufactured by Kao Corporation, a polyoxyethylene nonylphenol ether type nonionic surfactant) was dissolved in water. 10
When development was carried out for 5 minutes with stirring in a developer solution at 60° C. containing 2 parts to 00 parts, a glass substrate was obtained that had a dyeable film only in the areas irradiated with UV through the mask. This glass plate was further post-baked at 160° C. for 30 minutes, resulting in a film thickness of 0.5 μm. This substrate was dyed in the same dye bath as in Example 1 at pH 5.0 at 50° C. for 10 minutes, washed with water and dried to obtain a colored pattern film. The dyeing density (absorbance) of this colored pattern film is 0.5 (680n) on the cyan side.
m) was 1.48 (435 nm) on the yellow side, and the maximum transmittance was 70.3% (530 nm).

Example 4 A dyeable resin pattern film obtained in the same manner as in Example 1 was treated with a phthalocyanine dye of formula (2).
pH 5.0 in a dyebath prepared by dissolving a mixture of 5 parts of ethylene urea, 10 parts of ethylene urea, and 2 parts of ammonium sulfate in 100 parts of water.
It was dyed at 70°C for 20 minutes, washed with water and dried to obtain a cyan colored pattern. The dyeing density (absorbance) of this colored pattern film was 0.83 (635 nm), and the maximum transmittance was 90%.

[0024]

[Case 2]

(In formula (2), Pc represents a phthalocyanine residue, X represents 1 to 4, and y represents 0 to 3.)

Example 5 FCR-500 (
A photosensitive solution prepared by mixing 5 parts of gelatin (manufactured by Fuji Pharmaceutical Co., Ltd.) with 1 part of an 8% aqueous solution of ammonium dichromate was applied to a film thickness of 1 μm using a spin coating method, and then coated at 75°C for 10 minutes. After drying for a minute, it was exposed to light through a prescribed mask. Subsequently, after immersion in water for 3 minutes and development, a dyeable resin pattern film was obtained on the substrate. Next, this pattern film was dyed in the same dye bath as in Example 4 at pH 5.0 and 70° C. for 10 minutes, washed with water and dried to obtain a cyan colored pattern. The dyeing density (absorbance) of this colored pattern film is 0.
99 (635 nm) maximum transmittance was 93%.

Example 6 FCR-500 (
A photosensitive solution prepared by mixing 5 parts of gelatin (manufactured by Fuji Pharmaceutical Co., Ltd.) with 1 part of an 8% aqueous solution of ammonium dichromate was applied to a film thickness of 1 μm by spin coating, and dried at 75°C for 10 minutes. After that, it was exposed to light through a prescribed mask. Subsequently, after immersion in water for 3 minutes and development, a dyeable resin pattern film was obtained on the substrate. Next, this pattern film was mixed with 0.5 parts of phthalocyanine dye represented by formula (1) and 1 part of water.
The dyeing was carried out in a dye bath prepared by adding 4 parts of ammonium chloride to an aqueous solution consisting of 0.00 parts at pH 6.0 at 60° C. for 10 minutes, and the water dye was dried to obtain a green colored pattern. The dyeing density (absorbance) of this coloring pattern is 2.0 (68
The transmittance was 3.0 (435 nm) on the yellow side, and the maximum transmittance was 61% (530 nm).

Example 7 A dyeable resin pattern film obtained in the same manner as in Example 6 was treated with a phthalocyanine dye of formula (1).
5 parts of ammonium acetate and 100 parts of water.
1 part at pH 6.0 and 60°C.
It was dyed for 0 minutes, washed with water and dried to obtain a green colored pattern. The dyeing density (absorbance) of this coloring pattern is 2.
0 (680 nm) and 3.0 (435 nm) on the yellow side, and the maximum transmittance was 60% (530 nm).

Comparative Example 1 A dyeable resin pattern film obtained in the same manner as in Example 1 was dyed in a dye bath similar to that of Example 1, except that it did not contain urea and ammonium chloride, at pH 5 and 70°C.
Stained for 0 minutes. Next, after washing with water and drying, the dyeing density (absorbance) of this colored pattern film was measured to be 0.18 (on the cyan side).
680 nm), and 0.14 (435 nm) on the yellow side.

Comparative Example 2 A dyeable resin pattern film obtained in the same manner as in Example 3 was dyed in the same dye bath as in Example 1, except that it did not contain urea and ammonium chloride, at a pH of 5 and 50°C for 10 minutes.
Stained for minutes. After washing with water and drying, the dyeing density (absorption color) of this colored pattern film was measured to be 1.1 on the cyan side.
2 (680 nm), 1.48 (635 nm) on the yellow side,
Moreover, the maximum transmittance was 63.2% (535 nm).

Comparative Example 3 A dyeable resin pattern film obtained in the same manner as in Example 6 was dyed for 10 minutes at pH 6.0 and 60° C. in the same dye bath as in Example 6 except that it did not contain ammonium chloride. did. After washing with water and drying, the dyeing density (absorbance) of this green pattern was measured to be 0.64 (absorbance) on the cyan side.
80 nm), and 0.60 (635 nm) on the yellow side, and the maximum transmittance was 84.8% (535 nm).

[0032]

[Effects of the Invention] A darkly colored (dyed) patterned film useful as a color filter was obtained, and this film showed excellent optical properties.

Claims (1)

[Claims] Claim 1: A color filter obtained by dyeing a film placed on a substrate in the presence of ureas and/or inorganic salts.