JP4029461B2 - Color filter and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a color filter provided for various display devices such as a plasma display, an electroluminescence display, a field emission display, a liquid crystal display, and a solid-state imaging device, and used for reducing reflectance, color synthesis, or color separation, and a method for manufacturing the same. About.
[0002]
[Prior art]
For example, a color liquid crystal display requires a color filter for performing color display, and a color filter created by a known dyeing method or pigment dispersion method is used. This is a color filter obtained by coloring a resin layer with an organic dye or organic pigment.
In plasma displays, it has been proposed to use color filters to improve the contrast when images are displayed. Thus, in some display devices, color filters are indispensable for color display and image quality improvement. It has become.
[0003]
By the way, in the case of a plasma display, the manufacturing process includes a process of baking at about 600 ° C. If a color filter for a liquid crystal display is diverted to a color filter for a plasma display, the organic dye, organic pigment, and resin binder that composes the color filter undergo a combustion or decomposition reaction in such a production process, and characteristics as a color filter are obtained. It will disappear.
[0004]
As a solution to this problem, it has been proposed to use a heat-resistant inorganic pigment formed on a substrate as a color filter.
This is done by patterning a paste in which an inorganic pigment is mixed with an appropriate binder resin and a solvent by a method such as screen printing on a predetermined substrate, and then baking the paste to remove the binder resin and the solvent. To get. In this case, since the color filter is an inorganic material, it can withstand a high-temperature process related to plasma display fabrication.
[0005]
[Problems to be solved by the invention]
When using color filters for plasma displays, electroluminescent displays, field emission displays, etc., transparent electrodes are wired above or below the color filters for the purpose of scanning and maintaining the pixels to be lit. Yes. In order for the display device to operate normally, it is extremely important not to cause disconnection or pinholes in the transparent electrode. For this reason, the dye layer not only has heat resistance but also chemical resistance in the electrode pattern wiring process and the substrate. Is required.
[0006]
Since the color filter manufactured by the conventional method is merely a pattern in which a dye layer is formed at a predetermined position on a substrate, the dye layer has a weak substrate adhesion.
[0007]
Such a dye layer cannot maintain sufficient substrate adhesion only by the adhesion between the pigments, and easily drops off in a series of paneling processes, and a product with stable quality cannot be obtained. In addition, in the structure in which the electrode pattern is wired on the dye layer, the dye layer causes chemical deterioration, discoloration, or fading in the wiring process, and color filter characteristics such as color separation and antireflection are impaired and display quality is improved. Reduce. In addition, disconnection or pinholes are generated in the electrode due to this defect, and the writing signal cannot be processed, and the video cannot be displayed as a display device.
[0008]
In order to ensure the characteristics of the dye layer and the transparent electrode without causing defects and defects with respect to such problems, it has been proposed to form a glass overcoat layer. However, since the glass material uses a low-melting glass frit, even if it is atomized, its particle size is limited to the range of 3 to 10 μm. However, it has not been possible to solve the problem of a decrease in the spectral transmittance of the filter.
[0009]
Accordingly, the present invention has been made to solve the above-described conventional problems, and an object thereof is to provide a color filter capable of improving the adhesion of the dye layer and maintaining the panel display quality, and a method for manufacturing the same. To do.
[0010]
Another object is to improve the reliability in each panel assembly process so that the filter layer is not altered, discolored, fading, wire electrode disconnection, pinholes, etc. Is provided, and a method for manufacturing the same.
[0011]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a substrate, a dye layer regularly arranged on the substrate, and a light-transmitting overcoat layer formed on the substrate so as to cover the dye layer. in becomes a color filter, Ri particles 5 up to 50 nm der constituting the overcoat layer, a color filter, wherein the particles have penetrated into the dye layer.
[0012]
According to a second aspect of the present invention, there is provided the color filter according to claim 1, wherein the overcoat layer is an insulating metal oxide layer.
[0013]
According to a third aspect of the present invention, in the color filter according to claim 2, the insulating metal oxide layer includes at least one insulating material selected from silicon, lithium, titanium, alumina, antimony, tin, zirconia, and yttrium. It is a color filter characterized by using a conductive metal oxide.
[0014]
According to a fourth aspect of the present invention, there is provided a process in which a dye layer on a substrate is regularly formed at a predetermined position on a substrate using a dye paste composed of an inorganic pigment, a binder resin, and a solvent; A step of applying a metal colloid solution having a particle size of 5 to 50 nm on the dye layer, a step of drying the metal colloid solution to obtain a hydrated gel film of metal colloids, and baking the dye layer and the dried metal colloid gel And a step of removing an organic component and forming an insulating metal oxide layer having light transmittance on the dye layer.
[0015]
According to a fifth aspect of the present invention, there is provided a process in which a dye layer on a substrate is regularly formed at a predetermined position on a substrate using a dye paste composed of an inorganic pigment, a binder resin, and a solvent; A step of baking the pigment layer to remove organic components, a step of applying and infiltrating a metal colloid solution having a particle diameter of 5 to 50 nm on the baked pigment layer, and a hydrated gel film of metal colloids by drying the metal colloid solution. And a step of forming a light-transmitting insulating metal oxide layer on the dye layer by subsequent firing, and a method for producing a color filter.
[0016]
Further, a sixth invention of the present invention is the method for producing a color filter according to claim 4 or 5, wherein the metal element of the metal colloid solution having a particle diameter of 5 to 50 nm includes silicon, lithium, titanium, alumina, antimony, A color filter manufacturing method using at least one of tin, zirconia, and yttrium.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view for explaining an embodiment of a color filter according to the present invention. As shown in the figure, a substrate 10 and dye layers 11R, 11G, and 11B of respective colors that are regularly arranged and patterned at predetermined positions; And an insulating metal oxide layer 12 covering the same.
As the substrate, those used for ordinary color filters can be used, and soda-lime glass, heat-resistant alkali-free glass such as borosilicate glass and aluminosilicate glass, and the like can be used.
[0018]
The dye layer 11 regularly formed at a predetermined position on the substrate is composed of an inorganic pigment.
[0019]
Examples of the inorganic pigment include Fe ₂ O ₃ as a red pigment, TiO ₂ —CoO—NiO—ZnO, CoO—CrO—TiO ₂ —Al ₂ O _{3 as} a green pigment, and CoO—Al ₂ O as a blue pigment. _3- CrO, CoO-Al ₂ O _{3 and the} like can be used, and other pigments such as yellow, brown, and black are used depending on applications.
[0020]
Next, on the glass substrate 10 on which each color pigment layer 11 is formed, a metal colloid solution in which metal colloids are adjusted to a liquid state is applied by, for example, spin coating to form a hydrogel coating film of the metal colloid solution. . The application method is not limited to the spin coating method, and it is possible to apply by a spray method, a dipping method, a flow coating method, or the like. At this time, the metal colloids penetrate more into the dye layer 11 and sufficiently penetrate between the pigment particles as the coating is dried gently (about 15 to 60 minutes) for a predetermined time after application of the solution.
Thereafter, firing is performed in an oxidizing atmosphere at a temperature of about 500 ° C. for several hours, thereby forming an insulating metal oxide layer 12 having optical transparency.
[0021]
According to such a method, the metal colloids uniformly formed on the surface of the dye layer 11 are decomposed and removed from the organic components such as the solvent and the binder of the dye layer 11 in the heating and baking step, and the resulting pigment is formed. Between the particles, sintering is performed while filling, and an insulating metal oxide layer 12 having light transmittance covering the surface of the dye layer 11 is formed. The color filter thus manufactured can significantly reduce the reaction between the dye layer 11 and the atmospheric gas even in a post-panel process as a display device.
[0022]
Further, the insulating metal oxide layer 12 having a light transmission property coated with the dye layer 11 can simultaneously obtain a function as an inorganic binder, so that the inorganic pigment particles constituting the dye layer 11 significantly improve the adhesion to each other, Even after passing through a series of paneling processes, it is possible to prevent pigment particles from dropping and alteration, discoloration or fading in the electrode wiring process. Therefore, the conventional problems described above can be solved.
[0023]
Here, the method for forming the light-transmissive insulating metal compound layer 12 after applying the metal colloid solution on the color filter substrate on which the dye layer 11 is formed on the substrate 10 has been described. After forming 11R, 11G, and 11B, firing is performed, and a metal colloid solution is applied thereon, the metal colloid solution is sufficiently permeated into the pigment particle gaps, and then dried and refired to have light transmittance. A similar effect can be obtained by a method of forming an insulating metal compound.
[0024]
The metal colloid solution described above is a colloidal form in which amorphous metal particles are dispersed in water, and the shape of the particles is preferably spherical. The metal element of the metal colloids is at least one of silicon, lithium, titanium, alumina, antimony, tin, zirconia, and yttrium, and the colloid particle diameter is in the range of 5 to 50 nm.
[0025]
If the colloidal particle diameter is 50 nm or more, the degree of filling when applied onto the dye layer 11 becomes insufficient, and a dense film cannot be obtained, and there is a possibility that adhesion and resistance to various chemicals may not be obtained. In addition, particles having a particle size of 5 nm or less are preferably in the above-mentioned range because it becomes difficult to stably disperse amorphous metal particles in a solution and aggregation occurs . If the particle element size is 5~50nm is of course it can be produced by the method of claims 4 to 6.
[0026]
Examples of colloidal dispersion media include water, alcohol solvents such as methanol, isopropanol, n-butanol, isobutanol and ethylene glycol, aromatic solvents such as toluene and xylene, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexane, Ether solvents such as dioxane, tetrahydrofuran and ethylene glycol mono n-propyl ether are used.
[0027]
【Example】
Hereinafter, a color filter and a method for manufacturing the color filter of the present invention will be described with reference to the drawings schematically showing the state of each stage in one embodiment. The material used in the explanation, and the material processing conditions such as temperature and time show a suitable example, and the drawings used in the explanation outline the size, shape, and arrangement relationship of each component. It is shown.
[0028]
<Example 1>
First, “Cobalt Blue X” manufactured by Toyo Pigment Co., Ltd. as a blue pigment and ethyl cellulose (manufactured by Kanto Chemical Co., Ltd.) and α-terpineol (manufactured by Kanto Chemical Co., Ltd.) as a binder resin are mixed at a predetermined ratio to prepare a blue paste dispersed in a roll mill. did.
[0029]
The blue paste was printed using a polyester 300 mesh screen plate opened in stripes, and a dye layer 11B having a stripe pattern with a line width of 150 μm, a pitch of 220 μm, and a film thickness of 8 μm was printed on the soda-lime glass substrate 10. .
[0030]
In the same manner, “ND-801” manufactured by NIPPON DENKO Co., Ltd. is used as a green pigment, and “Sicotrans Red L-2817” manufactured by BASF is used as a red pigment, and dispersed and pasted together with a binder resin to align the screen plate. The green stripe pattern dye layer 11G and the red stripe pattern dye layer 11R were printed at predetermined positions (FIG. 2). Both had a line width of 150 μm and a film thickness of 8 μm.
[0031]
Thereafter, a colloidal solution in which spherical anhydrous silicic acid (SiO ₂ ) having a particle size of 10 to 20 nm obtained by heating, reacting and dissolving colloidal silicic acid and caustic soda in autoclave is dispersed in water at a solid content ratio of 20%. Was coated on the entire surface of the substrate 10 on which each color dye layer was formed by spin coating. Thereafter, it was gently dried (left at room temperature for 30 minutes), passed through a hydrogel from the colloidal solution, and then dried at 90 ° C. to obtain a dried gel coating film. In this manner, the dye layers 11R, 11G, and 11B and the dried gel coating of anhydrous silicic acid were sequentially formed on the soda lime glass substrate 10.
[0032]
Thereafter, baking is performed in an oxidizing atmosphere at about 530 ° C. for 60 minutes to remove organic components of the dye layer 11 and sintering of anhydrous silicic acid (SiO ₂ ), and blue, green, red on the glass substrate 10 is performed. A color filter in which a dye layer and a light-transmissive insulating metal oxide layer were sequentially laminated was manufactured (FIG. 1).
[0033]
The color filter substrate manufactured by the above process is shifted to the panel forming process of the display device, and an ITO film (Indium Tin Oxide) is formed on the upper surface of the color filter substrate by a sputtering method, and an arbitrary resist pattern is used as a mask. The transparent electrode was wired with an etching solution in which ferric chloride and hydrochloric acid were mixed. The dye layer 11 of the color filter substrate that has undergone these steps is free from problems such as alteration, discoloration, fading, peeling, cracking, and dropping, and the wiring electrodes are also excellent without disconnection or pinholes. The measurement result of the spectral transmittance of this color filter is shown in FIG.
[0034]
<Example 2>
In the same manner as in Example 1, the blue, green and red pastes were repeatedly printed on the soda lime glass substrate 10 by the screen printing method, and the stripe-shaped dye layers 11B, 11G and 11R having a line width of 150 μm and a film thickness of 8 μm. Formed. Thereafter, baking was performed at 500 ° C. for 60 minutes in an oxidizing atmosphere to remove organic components of the color filter.
[0035]
Thereafter, a colloidal solution in which spherical silicic acid (SiO ₂ ) having a particle size of 10 to 20 nm is dispersed in water at a solid content ratio of 20% is applied on the entire surface of the substrate 10 on which each color pigment layer is formed by spin coating. did. Thereafter, it was gently dried (left at room temperature for 30 minutes), passed through a hydrogel from the colloidal solution, and then dried at 90 ° C. to obtain a dry gel film. In this manner, the dye layers 11R, 11G, and 11B and the dried gel coating of anhydrous silicic acid were sequentially formed on the soda lime glass substrate 10.
[0036]
Thereafter, baking is performed in an oxidizing atmosphere at about 530 ° C. for 60 minutes to remove organic components of the dye layer 11 and sintering of anhydrous silicic acid (SiO ₂ ), and blue, green, red on the glass substrate 10 is performed. A color filter in which a dye layer and a light-transmissive insulating metal oxide layer were sequentially laminated was manufactured (FIG. 1).
[0037]
The color filter substrate manufactured by the above process is shifted to the panel forming process of the display device, and an ITO film (Indium Tin Oxide) is formed on the upper surface of the color filter substrate by a sputtering method, and an arbitrary resist pattern is used as a mask. The transparent electrode was wired with an etching solution in which ferric chloride and hydrochloric acid were mixed. The dye layer 11 of the color filter substrate that has undergone these steps is free from problems such as alteration, discoloration, fading, peeling, cracking, and dropping, and the wiring electrodes are also excellent without disconnection or pinholes. The measurement result of the spectral transmittance of this color filter is as shown in FIG.
[0038]
<Example 3>
In the same manner as in Example 1, the blue, green and red pastes were repeatedly printed on the soda lime glass substrate 10 by the screen printing method, and the stripe-shaped dye layers 11B, 11G and 11R having a line width of 150 μm and a film thickness of 8 μm. Formed. Thereafter, baking was performed at 500 ° C. for 60 minutes in an oxidizing atmosphere to remove organic components of the color filter.
[0039]
Next, an alumina colloidal solution in which spherical alumina (Al ₂ O ₃ ) having a particle diameter of 10 to 20 nm is dispersed in water at a solid content ratio of 20% is spin-coated on the substrate 10 on which each color pigment layer is formed by spin coating. The entire surface was coated by the method. Thereafter, it was dried gently (left at room temperature for 30 minutes), passed through a hydrous alumina gel from the colloidal solution, and then dried at 90 ° C. to obtain a dry alumina gel film. In this way, the pigment layers 11B, 11G, and 11R and the dried alumina gel coating film were sequentially formed on the soda lime glass substrate 10.
[0040]
Thereafter, baking is performed at about 520 ° C. in an oxidizing atmosphere for 60 minutes to sinter the alumina gel on the dye layer 11, and the blue, green, and red dye layers on the glass substrate 10 and the light-transmitting insulation. A color filter in which a conductive metal oxide layer was sequentially laminated was manufactured (FIG. 1).
[0041]
The color filter substrate manufactured by the above process is shifted to the panel forming process of the display device, and an ITO film (Indium Tin Oxide) is formed on the upper surface of the color filter substrate by a sputtering method, and an arbitrary resist pattern is used as a mask. The transparent electrode was wired with an etching solution in which ferric chloride and hydrochloric acid were mixed. The dye layer 11 of the color filter substrate that has undergone these steps is free from problems such as alteration, discoloration, fading, peeling, cracking, and dropping, and the wiring electrodes are also excellent without disconnection or pinholes. The measurement result of the spectral transmittance of this color filter is as shown in FIG.
[0042]
<Example 4>
In the same manner as in Example 1, a striped blue, green, and red pigment layer 11 is formed on a soda lime glass substrate 10 and baked in an oxidizing atmosphere at 500 ° C. for 60 minutes to remove organic components of the color filter. did.
[0043]
Next, a colloidal solution in which lithium silicate having a particle size of 10 to 20 nm (SiO ₂ / LiO ₂ molar ratio 3.5) was dispersed in water at a solid content ratio of 20% was similarly applied to the entire surface of the substrate by spin coating. Then, it dried at 90 degreeC and formed the pigment | dye layer 11B * 11G * 11R and the dry lithium silicate coating film one by one.
[0044]
Thereafter, baking is performed in an oxidizing atmosphere at about 530 ° C. for 60 minutes to sinter lithium silicate on the dye layer 11, and the blue, green, and red dye layers and the light transmissive insulation are formed on the glass substrate 10. A color filter in which a conductive metal oxide layer was sequentially laminated was manufactured (FIG. 1).
[0045]
In the color filter substrate manufactured by the above steps, the light-transmitting insulating metal oxide layer 12 is filled and penetrated into the surface and inside of the dye layer 11. The lithium silicate solution was low in viscosity and excellent in permeability, and the cured product had improved film strength.
[0046]
This color filter substrate is shifted to a panel forming process of a display device, and an ITO film (Indium Tin Oxide) is formed on the upper surface of the color filter substrate by a sputtering method, and then an arbitrary resist pattern is used as a mask with ferric chloride. The transparent electrode was wired with an etching solution mixed with hydrochloric acid. The dye layer 11 of the color filter substrate that has undergone these processes is free from problems such as alteration, discoloration, fading, peeling, cracking, and dropping, and the wired electrodes are similarly free from disconnection and pinholes. Met. The measurement result of the spectral transmittance of this color filter is as shown in FIG.
[0047]
<Comparative example>
In the same manner as in Example 1, the blue, green and red pastes were repeatedly printed on the soda lime glass substrate 10 by the screen printing method, and the stripe-shaped dye layers 11B, 11G and 11R having a line width of 150 μm and a film thickness of 8 μm. Formed. Thereafter, baking was performed at 500 ° C. for 60 minutes in an oxidizing atmosphere to remove organic components of the color filter.
[0048]
Next, ethyl cellulose (manufactured by Kanto Chemical Co., Inc.) using a low melting point glass frit having an average particle diameter of 5 μm composed of PbO, SiO ₂ , B ₂ O ₃ , Na ₂ O, and F ₂ as a glass raw material and α- Terpineol (manufactured by Kanto Chemical) was kneaded at a predetermined ratio to prepare a low melting point glass paste.
[0049]
Thereafter, a glass paste was printed using a polyester 300 mesh screen and dried at 100 ° C. for 30 minutes.
[0050]
Thereafter, baking is performed in an oxidizing atmosphere at about 520 ° C. for 60 minutes to remove organic components of the low melting point glass paste on the dye layer 11 and soften the glass frit. A color filter in which the dye layer 11 and the overcoat glass layer were sequentially laminated was manufactured. The film thickness of the overcoat glass layer was 20 μm.
[0051]
The color filter substrate manufactured by the above process is transferred to the panel forming process of the display device, ITO (Indium Tin Oxide) is formed on the upper surface of the color filter substrate by a sputtering method, and an arbitrary resist pattern is used as a mask. The transparent electrode was wired with an etching solution in which ferric acid and hydrochloric acid were mixed. As a result of inspecting the color filter substrate having undergone such a process, a defect region in which many pinholes existed in the overcoat glass layer and the etching solution penetrated from this portion to discolor the dye layer 11 was confirmed. Moreover, the etching property of PbO which is an overcoat glass component was not resistant and the surface was clouded. The measurement result of the spectral transmittance of this color filter is shown in FIG.
[0052]
【The invention's effect】
As described above, according to the present invention, since the insulating metal oxide layer having light transmittance covers at least a part of the pigment particles constituting the dye layer, Oxidation or reduction reaction between the atmospheric gas and the pigment particles can be avoided in the firing treatment. Further, it has an extremely excellent effect that does not cause problems such as peeling, cracking, alteration, discoloration, or fading of the dye layer even after the electrode wiring process.
[0053]
In addition, after using a colloidal solution in which ultrafine particles having a particle diameter of 5 to 50 nm are dispersed in an insulating metal oxide layer having optical transparency and sufficiently infiltrating between the inorganic pigment particles constituting the dye layer, Sintering can provide a function of firmly bonding inorganic pigment particles as an inorganic binder. Since this gel film coated with colloidal solution and dried has hydroxyl groups on the particle surface, it is dehydrated by heating in the sintering process and has a structure in which the particles are firmly bonded via oxygen atoms. Obtain (Figure 3). The film thus obtained is free from defects such as cracks and peeling of the film itself against external stress. As a result, even after the formation of the wiring electrode on the upper part of the color filter and the display device paneling process, the dye layer did not deteriorate, discolor, fade, peel, crack or drop off. Also, the wiring electrode has an excellent effect without causing problems such as disconnection and pinholes.
[0054]
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a color filter of the present invention.
FIG. 2 is a manufacturing process diagram of a color filter according to an embodiment of the present invention.
FIG. 3 is a manufacturing process diagram of a color filter according to an embodiment of the present invention.
FIG. 4 is a graph showing spectral transmittance measurement results of a color filter according to an embodiment of the present invention.
FIG. 5 is a graph showing spectral transmittance measurement results of a color filter as a comparative example.
[Explanation of symbols]
10 ... Glass substrate 11 ... Dye layer 11B ... Dye layer (blue)
11G ... Dye layer (green)
11R ... Dye layer (red)
12 ... Overcoat layer

Claims (6)

In the color filter comprising a substrate, a dye layer regularly arranged on the substrate, and a light-transmitting overcoat layer formed on the substrate so as to cover the dye layer, the overcoat layer 5 up to 50 nm der constituting the particles is, the color filter, wherein the particles have penetrated into the dye layer.   2. The color filter according to claim 1, wherein the overcoat layer is an insulating metal oxide layer.   3. The color filter according to claim 2, wherein at least one insulating metal oxide of silicon, lithium, titanium, alumina, antimony, tin, zirconia, and yttrium is used for the insulating metal oxide layer. And a color filter. A step in which a dye layer on a substrate is regularly formed at a predetermined position on the substrate using a dye paste composed of an inorganic pigment, a binder resin, and a solvent; and a metal colloid having a particle diameter of 5 to 50 nm on the dye layer A step of applying a solution, a step of drying the metal colloid solution to obtain a water-containing gel film of metal colloids, baking the pigment layer and the dried metal colloid gel to remove organic components, and And a step of forming an insulating metal oxide layer having light transparency. A step in which the dye layer on the substrate is regularly formed at a predetermined position on the substrate using a dye paste composed of an inorganic pigment, a binder resin, and a solvent; and a step of firing the dye layer to remove organic components A step of applying a metal colloid solution having a particle size of 5 to 50 nm on the baked dye layer and infiltrating it, a step of drying the metal colloid solution to obtain a hydrated gel film of metal colloids, and a baked dye after that Forming a light-transmitting insulating metal oxide layer on the layer.   6. The method for producing a color filter according to claim 4, wherein at least one of silicon, lithium, titanium, alumina, antimony, tin, zirconia and yttrium is used as the metal element of the metal colloid solution having a particle diameter of 5 to 50 nm. A method for producing a color filter, characterized by being used.

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