JP2001154010A - Color paste composition for baking and heat-resistant color filter using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color paste composition, having sufficient fixing strength to a transparent substrate and to provide a heat-resistant color filter having superior color characteristics suitable for a display device such as a field emission display, fluorescent display device, discharge display panel and color liquid crystal display and for a solid-state image pickup device. SOLUTION: Color paste composition for baking contains (A) an inorganic or organic phosphorus compound, (B) inorganic color pigment and (C) resin as the main components. The heat-resistant color filter has a color pattern layer, which is formed on a transparent substrate and which contains a phosphate glass and an inorganic color pigment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a firing paste composition for forming a coloring layer containing an inorganic coloring pigment as a coloring material by firing. The present invention also relates to a heat-resistant color filter applied to a display device such as a field emission display, a fluorescent display device, a discharge display panel, and a color liquid crystal display, or a solid-state imaging device.

[0002]

2. Description of the Related Art Conventionally, in a liquid crystal display, a color filter having a color characteristic of a desired color light is used for displaying a color image. These color filters are formed by a dyeing method, a pigment dispersion method, a printing method, or the like. A resin layer colored with a pigment or an organic dye is used as a color filter. (M.Tani, et al: "LCD Color Filters: Characterist
ics and Future Issues ", SID 95 SEMINAR LECTURE (199
In addition, in a cathode ray tube display (CRT), a low-speed electron beam fluorescent display panel, a discharge display panel, etc., a color filter is used to reduce the reflectance when displaying an image and to control color characteristics. It has been proposed. (T.Ito, et al: "Micro
filterTM "ColorCRT, SID 95 Digest, p.25 (1995), etc.) As described above, in a display device, a solid-state image sensor, or the like, using a color filter for the purpose of reducing reflectance and controlling color characteristics is not sufficient for color. This is an effective means for improving the display image quality.

[0003] In the case of a field emission display or a discharge display panel, about 45 minutes are required in the manufacturing process.
A process of melting low-melting glass at a temperature of 0 ° C. and sealing two glass substrates is used. Therefore, when a color filter for a liquid crystal display is used as the color filter, the organic component constituting the color filter causes a reaction such as combustion and decomposition due to high heat during the manufacturing process, so that characteristics as a color filter are obtained. I can't do that.

As a solution to this problem, it has been proposed to use a color filter in which an inorganic coloring pigment is dispersed as a coloring material in a low-melting glass. (See Sakai et al .: “Ultra-low reflectivity color display discharge panel (III)” Television Society Technical Report, ED993, IPD113-8 (1986-11), etc.) A colored pattern layer is formed by screen printing on pixel portions on the glass substrate using low-melting glass powder and a paste made of an organic resin component for temporarily fixing these on a glass substrate. The color filter is obtained by baking the printed colored pattern layer at about 600 ° C. to burn off the organic resin component and the like, melt the glass powder, and fix the inorganic colored pigment to the glass substrate. In this case, since all of the colored pattern layers are made of an inorganic material, the colored pattern layers have durability against a high-temperature process involved in manufacturing.

[0005] However, low melting glass powder is relatively expensive, and generally has a glass powder that can withstand about 60%.
At a temperature of 0 ° C., the powdery low-melting glass does not completely melt, so that the low-melting glass cannot uniformly fill the pores formed by burning out the organic resin component and the like. It cannot exhibit sufficient transparency. That is, the strength of fixing of the colored pattern layer required in the manufacturing process, such as prevention of peeling of the colored pattern layer at the time of handling the substrate, is insufficient, and scattering of incident light due to a difference in refractive index between the inorganic colored pigment and air is prevented. At the same time, there is a problem that the color pattern layer is whitened and the color characteristics are deteriorated at the same time that the color pattern layer cannot be sufficiently suppressed.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made to solve such problems, and an object of the present invention is to provide a colored paste composition having a sufficient fixing strength to a transparent substrate. Another object of the present invention is to provide a heat-resistant color filter having excellent color characteristics, which is suitable for a display device such as a field emission display, a fluorescent display device, a discharge display panel, and a color liquid crystal display, and a solid-state imaging device.

[0007]

Means for Solving the Problems A first invention of the present invention is:
(A) an inorganic or organic phosphorus compound, (B) an inorganic color pigment,
(C) A colored paste composition for firing containing a resin as a main component.

A second invention of the present invention is a heat-resistant color filter, characterized in that the color pattern layer formed on the transparent substrate contains a phosphate glass and an inorganic color pigment.

A third invention of the present invention is the heat-resistant color filter according to claim 2, wherein said phosphate glass is contained in an amount of 0.1 to 50% by weight based on the weight of said inorganic coloring pigment.

[0010]

Embodiments of the present invention will be described below. As the inorganic or organic phosphorus compound (A) in the present invention, phosphoric acid such as orthophosphoric acid, metaphosphoric acid and pyrophosphoric acid can be used. In addition to phosphoric acid, various phosphates, phosphates, and the like can also be suitably used. The amount of (A) is such that the content of the phosphate glass produced by firing is from 0.1% by weight to 50% by weight, preferably from 1% by weight to 30% by weight, based on the inorganic color pigment. Decide the amount.

The (B) inorganic coloring pigment in the present invention functions as a coloring material. For this, an inorganic compound having heat resistance can be suitably used. For example, inorganic oxides exhibiting various colors called red iron oxide, cobalt green, cobalt blue, molybdate orange, titanium yellow, and cobalt purple can be used. It is also possible to appropriately adjust the color by mixing a plurality of these.

The resin (C) in the present invention is necessary for temporarily fixing the coloring material on the substrate. For example, vinyl acetate resin, ethyl cellulose, vinyl butyral resin, methyl methacrylate resin, nitrocellulose, polyvinyl alcohol, vinyl formal resin, shellac, rosin, polyethylene, acrylic resin, vinyl chloride resin, polyester resin, urea resin, phthalate An acid resin, a phenol resin, a polystyrene, a vinylidene chloride resin and the like can be used, and they can be suitably used alone or as a mixture of two or more kinds. However, in the heat-resistant color filter, it is not preferable that carbon in the organic component remains in a carbon-like state at the time of sintering, which affects color characteristics. Therefore, the organic component may be a compound having a short carbon chain. desirable. This resin is preferably used in an amount of 1 to 500 parts by weight, more preferably 5 to 300 parts by weight, based on 100 parts by weight of the colorant (B) inorganic coloring pigment.

[0013] Further, a solvent component can be suitably blended as required. As the solvent, it can be used arbitrarily according to the compatibility with the resin component and the like, the affinity with the coloring material, the pattern forming method, etc., and cyclohexanone, hexane,
Toluene, 2- (2-ethoxyethoxy) ethanol and the like can be suitably used. The amount is 100 resin components
5 to 400 parts by weight, more preferably 1 to 100 parts by weight,
0 to 200 parts by weight.

Further, if necessary, a silica such as ortho-silicic acid, meso-silicic acid, meso-di-silicic acid, meso-tri-silicic acid, meso-tetra-silicic acid or the like is used in order to more securely adhere to the glass substrate used as the transparent substrate. be able to. In addition to silica, various silicas, silicates, polysiloxanes, alkoxysilanes, and the like can be suitably used. The blending amount is (A)
1 to 10 with respect to 100 parts by weight of the inorganic or organic phosphorus compound
0 parts by weight, more preferably 10 to 50 parts by weight.
These materials are mixed into a colored paste by a known dispersion mixing method such as a disper mixer or a sand mill.

Next, a heat-resistant color filter according to the second and third aspects of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a heat-resistant color filter according to claim 2, which is one embodiment of the present invention. As shown in FIG. 1, the heat-resistant color filter 1 has a state in which a blue color material 5, a green color material 6, and a red color material 7 are dispersed in a phosphate glass 4 on a transparent substrate 2.
Are formed in a pixel shape such as a stripe shape or a mosaic shape. As the transparent substrate 2, any substrate having high transparency and excellent in various properties such as heat resistance and weather resistance can be used, but a glass substrate is generally used. The phosphate glass 4 can be obtained by reacting the colored paste composition for firing described in claim 1 at 400 ° C. or higher.

Here, the phosphate glass 4 contained in the colored pattern layer 3 formed on the transparent substrate 2 is made up of the respective color materials 5 to 7.
Is desirably contained in an amount of 0.1% by weight to 50% by weight. More preferably, it is 1% by weight to 30% by weight. When the content of the phosphate glass is less than 0.1% by weight with respect to the coloring material, the coloring pattern layer made of the coloring material is not sufficiently fixed to obtain a sufficient strength, and the coloring material formed by the burned-out organic component. The voids between them are not filled enough,
The scattering of incident light cannot be suppressed. 50% by weight
When the thickness exceeds the threshold value, the pores between the coloring materials when the organic component is burned out are sufficiently filled, and the strength due to the fixation is given. However, as the thickness of the layer increases, cracks are easily generated, and the color characteristics as well as the surface roughness are increased. Lower.

Next, as a method for forming the colored pattern layer 3, an inorganic coloring pigment, which is a coloring material, is dispersed in a resin by a known dispersion method such as a disper mixer or a sand mill. The organic phosphorus compound is mixed. It can be formed by patterning a sufficiently mixed colored paste on the transparent substrate 2 and performing a baking treatment at a high temperature exceeding 400 ° C.

The patterning method is optional, but in the production stage, printing, photolithography, electrophotography,
Generally, an electrodeposition method, a transfer method, or the like is used, and any method can be used. Here, a case where an alkali developing method which is one of the photolithography methods is used will be described. In the alkali development method, a photosensitive monomer, a photopolymerization initiator, and the like are suitably mixed with a resin having an acidic functional group such as a carboxyl group, and a pattern can be formed by utilizing photopolymerization and photocrosslinking reaction.

Examples of the photosensitive monomer include acrylates such as N-vinylpyrrolidone, ethyl acrylate and propyl acrylate, methacrylates such as ethyl methacrylate and propyl methacrylate, tetrahydrofurfuryl methacrylate, and modified caprolactone thereof. Examples include derivatives, styrene, α-methylstyrene, acrylic acid, and the like, and mixtures thereof. The amount is preferably 1 to 100 parts by weight, more preferably 5 to 80 parts by weight, per 100 parts by weight of the resin component.

Examples of the photopolymerization initiator include benzoin such as benzoin, benzoin methyl ether, and benzoin ethyl ether and alkyl ethers thereof; acetophenones such as acetophenone and 2,2-dimethoxy-2-phenylacetophenone; methylanthraquinone;
Anthraquinones such as ethylanthraquinone; thioxanthones such as thioxanthone and 2,4-diethylthioxanthone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenones such as benzophenone and 4,4-bismethylaminobenzophenone and azo compounds; Triazine compounds and the like can be suitably used alone or as a mixture of two or more. The amount used is preferably from 1 to 50 parts by weight, more preferably 5 to 50 parts by weight, based on 100 parts by weight of the photosensitive monomer.
-30 parts by weight.

Further, a solvent component can be suitably blended as required. The solvent can be used arbitrarily according to the compatibility with the resin component and the like, the affinity with the coloring material, the pattern forming method, and the like, and the compounding amount is 5 to 400 parts by weight with respect to 100 parts by weight of the resin component. Parts, more preferably 10
200 parts by weight. Furthermore, various compounding components can be suitably compounded as needed in addition to known general additives and fillers. For example, a wetting agent and a dispersant for improving the wettability of the coloring material to a resin component and a solvent and for imparting dispersion stability, a leveling agent for imparting smoothness when a colored paste is formed into a film, and adjusting the viscosity of the colored paste. A rheology control agent or the like can be suitably blended. The compounding amount of the wetting agent and the dispersant is based on 100 parts by weight of the coloring material.
0.1 to 30 parts by weight is desirable, and more preferably 0.1 to 30 parts by weight.
5 to 20 parts by weight. The amount of the leveling agent or the rheology control agent is preferably 0.1 to 30 parts by weight, more preferably 0.5 to 20 parts by weight, based on 100 parts by weight of the resin component.

Here, a mixture of the above-mentioned colored paste composition and the above-mentioned photosensitive monomer and photopolymerization initiator is screen-printed on a transparent substrate. Then, after being exposed and cured using a photomask, the unexposed portions are removed with an alkali developing solution and dried to form a colored pattern layer. The thickness of the colored pattern layer patterned on the substrate,
0.5 to 30 μm is desirable. More preferably 1-2
0 μm.

Each color pattern formed as described above is
A baking treatment is performed at a high temperature exceeding 00 ° C. in the atmosphere or an inert gas atmosphere to obtain a color filter. The thickness of the colored pattern layer after firing is desirably 0.1 to 20 μm, and more desirably 1 to 10 μm.

[0024]

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples. In addition, notation of "part" and "%" is based on weight unless otherwise specified. <Example 1> First, 50 parts of butyl methacrylate, 20 parts of methyl methacrylate, and 30 parts of methyl acrylate
Copolymerization is performed using (2-ethoxyethoxy) ethanol as a solvent to produce an acrylic resin. The acrylic resin solution was adjusted so that the solvent had a ratio of 60 parts to 40 parts of the acrylic resin. Then, based on 20 parts of this acrylic resin solution, 3.1 parts of orthophosphoric acid as a phosphorus compound, 32 parts of a blue pigment (Super Blue CR2 manufactured by Asahi Chemical Industry Co., Ltd.) as a coloring material, and 2- (2-ethoxyethoxy) as a solvent. ) 43 parts of ethanol and 1.5 parts of orthosilicic acid as a silicon compound were pre-dispersed with a disper, and then bead mill (Eiger miniminimill mote manufactured by Eiger Japan)
Dispersed for 1 hour in r).

Next, 2 parts of dipentaerythritol and 2 parts of hexaacrylate as photosensitive monomers and 1 part of a photopolymerization initiator piperonyltrichloromethyl S-triazine were mixed by a disper. This blue paste was screen-printed on a transparent glass substrate using a stainless steel screen plate having a thickness of 325 mesh and a thickness of 80 μm.
After leaving the film surface smooth by leaving it to stand for 70 minutes, it was dried at 70 ° C. for 20 minutes.

Next, a photomask having a light-shielding film in which a stripe pattern having a length of 200 mm and a width of 210 μm was repeatedly formed at a pitch of 450 μm was brought into close contact with each other, and was subjected to close contact exposure with an ultrahigh pressure mercury lamp at an exposure amount of 150 mJ / cm ² . After exposure, an alkaline developing solution at a temperature of 20 ° C. is ejected at a pressure of 1
Spray development was performed at kg / cm ² for 90 seconds to remove an unexposed portion to expose the glass substrate. After drying the substrate after the development treatment, the substrate was heated at 230 ° C. for 1 hour to perform a hardening treatment. The thickness of the blue pattern layer after hardening was 4.1 μm.

On the substrate on which the blue pattern layer is formed,
Green pigment as a color material (manufactured by Dainichi Seika Kogyo Co., Ltd .: TM
A green paste having the same composition as described above was prepared using GREEN # 3340) and then applied under the same conditions as described above. Next, using a photomask similar to the above, an exposure amount of 400 mJ
/ Cm ² for contact exposure. After exposure, an alkali developing solution at a temperature of 20 ° C. was spray-developed for 60 seconds at a jetting pressure of 1 kg / cm ² to remove unexposed portions and expose the glass substrate. After drying the substrate after the development treatment, the substrate was heated at 230 ° C. for 1 hour to perform a hardening treatment. The thickness of the green pattern layer after hardening was 5.2 μm.

In the same manner as in the formation of the blue and green pattern layers, a red pigment (manufactured by Dainichi Seika Kogyo Co., Ltd.) is used as a coloring material.
(TOR) to adjust the red paste to form a pattern. At this time, the thickness of the red pattern was 2.3 μm. Then, the substrate is heated at a temperature rising rate of 4 ° C. per minute in the air atmosphere, baked at a temperature of 440 ° C. for 60 minutes, and further continuously heated up to 600 ° C.
After baking for 2 minutes, when the substrate was cooled at a temperature lowering rate of 4 ° C. per minute, the organic resin component of each color pattern layer was burned off, and the phosphoric acid and silicic acid contained therein reacted to react with SiO _2.
P ₂ O ₅ was formed, and a pattern composed of each color material was fixed to the substrate, and the pattern was covered (see FIG. 1). Note that SiO ₂ · P ₂ O ₅ could be confirmed by an electron beam analyzer and X-ray diffraction. The thicknesses of the blue, green, and red pattern layers after firing are 3.7 μm and 4.7, respectively.
μm and 2.0 μm.

<Example 2> Next, tributyl phosphate 8.5 was used.
A blue paste having the same composition as in Example 1 was prepared using the parts, and a pattern was formed under the same conditions as described above to form a blue pattern layer having a thickness of 4.3 μm after the heat hardening treatment. Next, green and red pattern layers were sequentially formed on the substrate in the same manner as the blue pattern layer. The thickness of the green pattern after the hardening treatment is 5.7 μm, and the thickness of the red pattern is 2.7 μm.
Met. This substrate was heated in the air atmosphere at a temperature rising rate of 4 ° C. per minute in the same manner as described above, continuously further heated to 600 ° C., baked at a temperature of 600 ° C. for 45 minutes, and baked at a temperature of 440 ° C. for 60 minutes. Thereafter, the substrate is cooled at a temperature lowering rate of 4 ° C. per minute, and the organic resin component of each color pattern is burned and removed, and SiO ₂ · P ₂ O ₅ is formed. And the pattern was covered (see FIG. 1). Also at this time, SiO ₂ · P ₂ O ₅ could be confirmed by an electron beam analyzer and X-ray diffraction. The thickness of each of the blue, green, and red pattern layers after firing is 3.9.
μm, 5.1 μm, and 2.2 μm.

<Comparative Example 1> In order to compare the color characteristics of the heat-resistant color filters produced in Example 1 and Example 2, low-melting glass powder (GA-9, manufactured by Nippon Electric Glass Co., Ltd.) was used. A similar heat-resistant color filter was produced using each color paste having a composition using the same inorganic pigment as in Examples 1 and 2 as a coloring material. The thicknesses of the blue, green, and red pattern layers after patterning were 4.4 μm, 5.3 μm, and 2.1 μm. The film thickness after firing is 3.6 μm and 4.8 μm, respectively.
m, 1.7 μm.

<Evaluation> Examples 1, 2 and Comparative Example 1
2, 3 and 4 show the results of measuring the transmission spectrum of each color pattern using a spectrophotometer (spectrophotometer UV3100 manufactured by Shimadzu Corporation). 2, 3,
In the heat-resistant color filters obtained in Example 1 and Example 2 from the results in FIG. 4, the difference between the maximum value and the minimum value of the transmittance curve in the visible range is larger than that of Comparative Example 1 for any color. It was found that high contrast was obtained and the color characteristics were improved. In addition, the color filters of Examples 1 and 2 did not have any peeling of the colored pattern layer during this handling.

[0032]

When the colored paste composition for firing of the present invention is used for a colored pattern layer of a color filter, the colored pattern layer is fixed on the transparent substrate with sufficient strength, and the organic component from which the phosphate glass has been burned off. By filling the voids between the color materials formed by the above and covering the pattern, it is possible to obtain a heat-resistant color filter in which scattering of incident light is suppressed and color characteristics are improved.

[0033]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a heat-resistant color filter showing one embodiment of the present invention.

FIG. 2 shows a spectral transmittance curve of a heat-resistant color filter manufactured according to Example 1.

FIG. 3 shows a spectral transmittance curve of a heat-resistant color filter manufactured in Example 2.

FIG. 4 is a spectral transmittance curve of a heat-resistant color filter manufactured according to Comparative Example 1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Heat resistant color filter 2 ... Transparent substrate 3 ... Colored pattern layer 4 ... Phosphate glass 5 ... Blue color material 6 ... Green color material 7 ... Red color material

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 2H025 AA10 AB13 BC85 CA02 CA03 CA04 CA09 CA11 CA23 2H048 BA45 BA47 BA48 BB14 BB32 4J037 AA08 AA15 AA21 CA22 CA25 CC02 CC12 CC13 CC14 CC15 CC16 CC22 CC24 DD19 DD23 EE08 EE30 FF13

Claims (3)

[Claims] 1. A firing paste composition comprising (A) an inorganic or organic phosphorus compound, (B) an inorganic color pigment, and (C) a resin as main components. 2. A heat-resistant color filter, wherein the color pattern layer formed on the transparent substrate contains a phosphate glass and an inorganic color pigment. 3. The method according to claim 1, wherein the phosphate glass is based on an inorganic color pigment.
The heat resistant color filter according to claim 2, wherein the color filter is contained in an amount of 0.1 to 50% by weight.