JPH0358002A - Color filter - Google Patents

Abstract

PURPOSE:To obtain a color filter, especially correcting a red dye and exhibiting superior spectral characteristics and reliability by coloring a colored pattern film on a base plate with a specified asymmetric (2:1) chromium complex salt dye. CONSTITUTION:The patternwise colored film on the base plate is colored with the asymmetric (2:1) chromium complex salt dye represented by formula I in which each of R1 to R4 is H or Cl, independently of each other, and M is H, Li, K, Na, NH4, mono-, di-, or tri-ethanolammonium. The film is colored by using this chromium complex salt dye, for example, by an immersion or printing method, preferably, by the immersion method using, especially, an aqueous solution, in a mixing ratio of the compound of formula I to the red anionic dye of (10:90)-(80:20).

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to color filters. For more details,
This invention relates to color filters with excellent optical properties used in liquid crystal display devices, color field devices, and sensors.

The conventional method for manufacturing color filters using the dyeing method is to coat the surface of a substrate such as glass or silicon wafer with a transparent thin film-like film of synthetic resin or gelatin containing cationic groups in the form of stripes or mosaics (called a pattern). A coat of protein-based natural polymer substances such as casein, glue, etc. is provided as a colored film, and this is dyed (colored) using a dye.
The basic principle is to do so. 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 colored layer. After that, the dye is fixed and resisted with tannic acid, etc. I'll give it a try. A second coating to be colored is applied using a similar procedure. Thereafter, if necessary, a colored layer is formed on the same substrate surface.

(3) A film to be colored (a colored film) is provided on the surface of the substrate. After a layer of bright resist is provided thereon, the colored film exposed in a pattern is dyed by exposure and development through a mask, and then the bright resist layer is peeled off to form a colored portion. Repeat the operations after forming the body resist layer,
The same colored film is dyed in multiple colors in a desired pattern.

Color filters manufactured by the above process usually have three primary colors: R (to), G (m), and B.
(blue) or the three complementary primary colors Y(2)M (magenta, LC (cyan), (M may be omitted).Required for color filters. The most important property is the optical property, and the spectral properties of each colored layer largely control the value of the final product.

In this regard, it has a high degree of resistance to the heat treatment required in the manufacturing process of liquid crystal display devices equipped with color filters, as well as to the light applied during use as a final product, and has specified optical properties. It must not be damaged. Naturally, the dyes applied must also have good solubility and solubility in water and be stable for long periods in acidic dye baths. By the way, since protein-based natural polymer substances such as gelatin, 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 a cationic group in the resin component, water-soluble anionic dyes can be used in the same way as protein-based natural polymer substances. Becomes stained.

In addition, as a method for producing color filters using dyes, in addition to the above method, a film of a colored resin composition in which dyes are dissolved in advance in a photocurable resin composition is provided on the substrate surface, and then the photolithography technique described above is used. It is also possible to adopt a method in which a patterned colored layer is provided on the substrate.

A number of water-soluble anionic dyes have been investigated in order to obtain dyes with the desired optical properties and reliability (mainly good resistance to heat and light). However, in the case of a primary red dye, it is difficult to satisfy the desired optical properties with a single dye, and it is inevitable to use a yellow or orange dye to correct the optical properties.

This correction dye must be highly compatible with the red dye used in combination, must not inhibit the properties of the red dye, and must have the same level of reliability. The current situation is that no dye has been found.

The spectral characteristics required for red dye are 5 of the dyed colored film.
When the wavelength that gives 0% transmittance, λT=50%, is adjusted to a predetermined wavelength (generally 600±2Qnm), 620~
Transmittance at 700 nm is close to Zoo%, 400
~540nm't: The transmittance is as small as possible, preferably 1% or less, but all conventionally known red dyes have a portion that exhibits a fairly large transmittance in the region of 400 to 540 nm. Yes, it transmits light other than red, and the transmitted light is no longer pure red. The spectral characteristics required for the dye used in combination to correct this are 6
It has absorption in the wavelength range of 0.01 m or more, that is, the transmittance is close to 100% (,400~520n
The purpose is to have a transmittance of 1% or less over the entire area of m, and to completely block transmitted blue light that makes red an impure k color. For the purpose of such correction, C. I.
A dye belonging to Acid Orange 56 is used, but this dye has the drawback of poor resistance to light and loss of correction ability over time.

Under these circumstances, we have developed a dye for color filters that has excellent spectral properties for correcting red dyes, has excellent light resistance and heat resistance, is compatible with red dyes, has excellent water solubility, and has excellent fixation resistance. development is desired.

Means for Solving the Problems The present inventors have developed the above-mentioned optical properties and excellent reliability (
As a result of our earnest efforts to find a color filter that has high solubility in water (light resistance, heat resistance), we discovered that a specific metal-containing azo compound has excellent solubility in water, and as a result, a dyed (colored) color filter that satisfies the optical properties described above. It was discovered that the reliability was also excellent, leading to the present invention. That is, the present invention is characterized in that in a color filter in which a patterned colored film is placed on a substrate, at least one pattern is colored with an asymmetric 2:1 chromium complex dye represented by the following formula (1). We provide color filters for

(In formula (1), Rl, Rz- R3 and R4 & are independently H or U, and M is Hr L L * K+
Na + NH4 means monoethanolammonium, diethanolammonium or triethanolammonium. ) The dye of formula (1) is prepared by known methods in the production of chromium complex dyes. That is, for example, an azo dye containing a sulfonic acid group, which is one of the components, is treated with a chromating agent to convert it into a 1:1 chromium complex salt, and this complex salt is reacted with an azomethine dye, which is another component. An asymmetric 2:1 chromium complex dye is obtained. As a chromating agent,
Trivalent chromium salts (chromium acetate, chromium salicylic acid, chromium chloride, etc.) can be used.

Then, if necessary, acidification treatment and ion exchange treatment are performed to remove metals, and then treatment with caustic soda, lithium hydroxide caustic potassium, ammonia, monoethanolamine, diethanolamine or triethanolamine is performed to obtain 2 of formula (1). =1 chromium complex dye is obtained.

Next, an example of the color filter of the present invention will be explained using the drawings. Figure 1 (a) to (h) are glass plates (substrate)
FIG. 2 is a conceptual diagram showing a method of manufacturing a color filter using a fixation method in which colored layers of different colors are provided on top using a fixation resist dyeing process.

Spin coating a mixture of a protein-based natural polymer such as gelatin, casein, or glue and a dichromate such as ammonium dichromate or a photocurable synthetic resin composition having a cationic group on a glass plate. It is applied by a method such as roller coating to a thickness of 0. 2~2μ
A photocurable thin film 2 is provided (FIG. 1(b)).

Next, a photomask 4 having a predetermined pattern on the thin film
The exposed area is cured by irradiating ultraviolet light 9 through the . (Figure 1 (C)).

Next, the unexposed areas are removed by development with water, etc., to form a colored layer 2' with a predetermined pattern (Fig. 1(d)), and a dye having predetermined optical properties to obtain the first color is applied. The first colored layer 2 is formed by dyeing using the dye (FIG. 1(e)).

Next, it is treated in an aqueous solution of a fixed resisting agent such as tannic acid tartrate to form a resisting thin film 3 (FIG. 1(f)).

Next, a photocurable coating layer for obtaining a colored layer is provided in the same manner as described above, and exposed and developed through a mask to form a colored layer in a predetermined pattern, and a second color is applied. In order to obtain a second
A colored layer 5 is formed (FIG. 1(g)).

Next, a resist dyeing layer is provided on the colored layer 5, and the next colored layer is provided.
In this way, it is also possible to form a colored layer of a third color, or even a colored layer of a fourth color.

In a direct-cut color separation color filter for solid-state imaging devices, a flattening layer is provided on a silicon wafer, which serves as a base, and on which a light detection section, etc. is provided, and a colored layer is formed thereon using the same procedure as described above. The same material as the non-staining protective film can be used for the planarization layer.

The colored layer may be primary colors R (f<), G (green), B (blue), or complementary colors Y (yellow), M (magenta).
, C (cyan).

In the present invention, the compound of formula (1) can be used alone, but it is more preferable to use it as a primary color.
Used as a correction dye to obtain a colored layer. By using this dye in combination with a red dye, the red colored layer has good spectral transmission characteristics, light resistance, heat resistance, etc., so it is possible to obtain faithful color reproducibility as a color separation color filter. Also, as a color filter for color display, it is possible to obtain color images with good color balance and excellent durability.

Protein-based natural polymer substances such as gelatin, casein, and glue as 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, arms, 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 the coated layer is cured by applying ultraviolet rays after uniformly coating it on a substrate such as glass using spin coating or roller coating. , a water-insoluble film is formed.

Further, examples of synthetic resins having a cationic group as a coloring material used in the present invention include the following.

That is, an anionic dye-dyeable polymer, a compound having two or more photoreactive unsaturated groups in one molecule, a diazide photosensitive compound, and optionally an organic solvent are used to form a group using a certain photoreactive resin composition. 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 is, for example, (N,N-dimethylamino)ethyl acrylate},
It is obtained by polymerizing a nitrogen-containing monomer such as (N,N-diethylamino)ethyl methacrylate, a hydrophilic monomer such as hydroxyethyl acrylate or dimethylamino acrylamide, and 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. In addition, examples of diazide photosensitive compounds include 4,4'-diazide chalcone,
Examples include 2,6-his(4'-7dopenzale)cyclohexanone. As the organic solvent used for diluting the resin composition, for example, methyl cellosolp, methyl ethyl ketone, toluene, etc. are used alone or in a mixed system.

Such a photoreactive resin composition is applied to the surface of a base material and cured by irradiation with actinic light such as ultraviolet rays to obtain a film.

Examples of photocurable anionic dye-dyeable synthetic resins 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 the main component, or a cationic group-containing polymer in which a photocrosslinking group such as chalcone, cinnamic acid, azide, or stilbazole group has been introduced into the polymer in advance, is mixed with water or organic A resin composition dissolved in a solvent may also be used.

To dye (color) the film using the asymmetric 2:1 chromium complex dye represented by formula (1), for example, a dipping method or a printing method is used, and a dipping method using an aqueous solution is particularly convenient. be. In this case, it is usually 0. 1 to 30 g, more preferably 1 to Log, of an asymmetric 2:1 chromium complex dye of formula (1) dissolved in water 11 with a usually red anionic dye.
The base material provided with the film is immersed in a dye bath at 0 to 100°C for usually 10 seconds or more and about 60 minutes, then taken out, washed with water, and dried. The red colored film thus obtained exhibits optical properties suitable for use as a color filter. The ceremony (
The mixing ratio of the compound 1) and the red anionic dye is 10:
A ratio of 90:20 to 80:20 is desirable.

An example of a method for forming a resist dyeing thin film on the colored layer is to immerse the colored layer in an acidic aqueous solution of tannic acid at 50 to 80°C for 5 to 30 minutes, and then in an aqueous solution of tartarite for 5 to 30 minutes at 50 to 80°C. A thin film made of tannic acid tartar is formed on the surface of the colored layer to both fix the dye and resist dyeing. When the compound of formula (1) is used alone, staining is carried out in the same manner as when it is used in combination.

In the present invention, glass, plastic sheets, silicon wafers, etc. may be used as substrates on which the coating to be dyed is provided, after being pretreated with a silane coupling agent or the like or provided with a flattening layer, if necessary. Ru.

Example The present invention will be explained in more detail by way of examples.

Example 1. On optical glass (a high-purity glass plate with excellent light transmission), 1 part of an 8% aqueous solution of ammonium dichromate was mixed with 4 parts of FCR-500 (manufactured by Fuji Pharmaceutical Co., Ltd., a gelatin aqueous solution) and degassed. A photosensitive solution was applied to a film thickness of 1μ using the Subin coating method, prebaked at 80°C for 10 minutes, and then exposed to an energy amount of 300 millijoules/cm2 using a mask alignment device MA-10 model (manufactured by Mikasa ■). Developed in warm water at 40°C. then 120
The gelatin film was hardened by post-baking at °C for 10 minutes.

Next, it was immersed in a 0.4% aqueous solution of the compound of formula (2) described below, whose pH was adjusted to 4 with acetic acid, at 70° C. for 10 minutes to obtain a colored layer. When the spectral transmittance curve of this colored layer was measured, the transmittance in the wavelength region of 400 to 520 1 m was over 90%, and it had perfect spectral characteristics as a red dye correction dye. .

Ultraviolet cut filter (manufactured by HOYA Corporation, L-4
When exposed to light for 80 hours using a standard fade meter (manufactured by Suga Test Instruments, model FAL-3H) through a standard fade meter (model FAL-3H), the decrease rate of optical density (-1ogT) at the maximum absorption wavelength of 500 nm of the yellow colored part was 1%. There was almost no fading.

Comparative Example The dye used for coloring was C.I. I. The spectral transmittance curve of the colored layer obtained by the same method as in Example 1 except that Acid Orange 56 was used was very similar to the curve obtained in Example 1. However, when the same light fastness test as in Example 1 was conducted, the reduction rate of the optical density (-1ogT) at the maximum absorption wavelength of 410 nm of the colored portion was 32%, and the color was noticeably faded.

Example 2, Dimethylaminopropylacrylamide 31
Part 2-Hydroxyethyl methacrylate
14-part vinylpyrrolidone
15 parts methyl methacrylate
15 parts methyl acrylate
13 parts dimethylamino acrylamide
10 parts dioxane
200 parts a,a'-azopis (imptilonitrile) 1 part The liquid of the above formulation was subjected to a polymerization reaction at 80°C for 5 hours in a nitrogen atmosphere, and then the polymerization solution was poured into a large amount of inglovir ether to form a polymer. After the fraction is precipitated, the polymer is taken out and dried.

To 15 parts of this dry polymer, 0.63 parts of 4,4'-diazide chalcone and 0.57 parts of subiloglycol diacrylate.
88 parts of ethyl cellosolve, 27 parts of diethylene glycol dimethyl ether, silane coupling agent KBM6
A dyeable photosensitive resin solution was prepared by mixing and dissolving 0.6 part of 03 (Shin-Etsu Chemical Co., Ltd.).

Next, coat this on a glass plate using the Subin coat method.
After drying at 80°C for 30 minutes, UV irradiation was performed for 5 seconds at a surface illuminance of 8 mw/cm through a mask with a pattern for resolution testing. ) was developed for 5 minutes with stirring in a developer solution at 60°C containing 2 parts per 1000 parts of water, to obtain a glass substrate having a dyeable film only in the irradiated area.
Post-baking was performed at 60°C for 30 minutes.

This glass plate is C. I. Acid Red 114 and formula (3
) of a 7:3 mixture with a compound of A 7% aqueous solution was immersed in a dye bath whose pH was adjusted to 4 with acetic acid at 70° C. for 10 minutes to obtain a patterned red colored layer. When the spectral transmittance curve of this colored layer was measured, the wavelength showing transmittance of 50%, λ = 50%, was 600 nm and C.I. I
．． The wavelength is the same as that obtained with Acid Red 114 alone, and when the compound of formula (3) is not used in combination, it is 420-4
The transmittance is more than 10% in the 5 Q nm region, which causes color mixture, but this drawback has been completely eliminated, and the transmittance is less than 1% in the wide wavelength region of 400 to 54 Q nm. , showed an ideal spectral transmittance curve as the primary color system R (to).

When the same light resistance test as in Example 1 was conducted, the result was 400-7
Q Q The change in transmittance is 2% in the entire wavelength range of nm.
It was within the range of 100%, and there was almost no fading.

Example 3. 8% of ammonium dichromate to 4 parts of FCR-500 (gelatin aqueous solution manufactured by Fuji Pharmaceutical Co., Ltd.) on optical glass.
A photosensitive liquid mixed with 1 part of an aqueous solution and degassed was applied to a film thickness of 1 μm using a spin coating method, and after blistering at 80°C for 10 minutes, it was applied to the mask alignment device MA- Type 10 (manufactured by Mikasa)
After exposure with an energy amount of 300 millijoules/cm'', the film was developed in warm water at 40°C.
The gelatin film was post-baked at C for 10 minutes to harden the gelatin film.

Then, the compound of formula (4) adjusted to pH 5 with acetic acid and C.I.
■． After immersing in a 0.8% aqueous solution of a mixture of Acid Red 249 in a ratio of 4=6 at 70'C for 10 minutes and washing with water, 0.0% of high tannic acid (manufactured by Dainippon Pharmaceutical ■) was added. 3
% and acetic acid 0. 2% in a bath at 70°C for 5 minutes, washed with water, then immersed in a 0.5% aqueous solution of 211 Paflon (manufactured by Inu Nihon Seiyaku ■, fixative) at 70°C for 5 minutes, washed with water, and then dried. A first red colored layer was provided.

Next, a photosensitive gelatin layer was provided in the same manner as above, exposed and developed, and the pH was adjusted to 5 with acetic acid.
Nippon Kayaku ■, blue dye for color filters) 0.5
% aqueous solution at 60° C. for 10 minutes, and then subjected to fixation resist dyeing treatment in the same manner as described above to provide a second blue colored layer.

Next, another part of the gelatin layer is coated with CFG as described above.
-51P (manufactured by Nippon Kayaku ■, green dye for Color Fino σ tar) 0. After staining in a 5% aqueous solution at 60°C for 15 minutes,
A fixed resist dyeing treatment was applied to provide a third green colored layer.

The obtained color filter consisted of three colors, blue, red, and green, and was suitable for use in liquid crystal color televisions. The spectral transmittance curve of the red colored part shows that the wavelength at which the transmittance is 50%, λT=50%, is 595 nm, and C.I.
I. The wavelength is the same as that obtained with Acid Red 249 alone, and when the compound of formula (3) is used in combination, the wavelength is 400~
The transmittance is more than 10% in the 43Q nm region, which causes color mixture, but this drawback has been completely eliminated, and the transmittance is less than 1% in the wide wavelength region of 400 to 5401 m. It showed desirable spectral characteristics as a primary color R (to).

4. Effects of the invention Used in liquid crystal display devices, color separation devices, sensors, etc., especially in combination with red dye, primary color R (red)
Excellent optical properties and reliability (especially heat resistance and light resistance)
A color filter showing the following was obtained.

[Brief explanation of drawings]

In Figure 1, 1 is a glass plate, 2 is a thin film of photocurable resin etc. provided by the Svin coating method, 2' is a film to be colored that is photocured through a mask, 2' is a colored layer, and 3 is a fixed film. A resist dyeing thin film provided by resist dyeing treatment, 4 a photomask, and 5 a second colored layer are shown. In FIGS. 1(a) to (h), 1 glass plate 2 photocurable thin film colored film first colored layer anti-staining thin film photomask second colored layer anti-staining thin film developing tank dyeing tank irradiation lamp are shown, respectively.

Claims (1)

[Claims] 1. In a color filter in which a patterned colored film is placed on a substrate, at least one pattern is colored with an asymmetric 2:1 chromium complex dye represented by the following formula (1). A color filter characterized by: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (1) (In formula (1), R_1, R_2, R_3 and R_4 each independently represent H or Cl, and M represents H, Li, K, Na
, NH_4 means monoethanolammonium, diethanolammonium or triethanolammonium. )