JPH06308314A - Production of color filter - Google Patents

Abstract

PURPOSE:To enable use of the color filter for a projection type color filter of a one-sheet panel system having improved reliability and transparency by applying a colored sol on a transparent substrate and drying this gel to form a colored gel, then heating the gel to form a colored film on the transparent substrate. CONSTITUTION:A liquid mixture contg. a metal alkoxide previously dissolved or uniformly dispersed with a coloring amt. of pigments is subjected to a hydrolysis or dehydration condensation reaction, by which the colored sol is formed. The colored sol is applied on the transparent substrate and is dried, by which the colored gel is formed. The gel is then heated, by which the colored film is formed on the transparent substrate. Further, the stages for forming the colored films consisting of a first stage for applying a photosensitive resist on the transparent substrate formed with transparent electrodes, a second stage for exposing the lower transparent electrodes by patterning this photosensitive resist to desired patterns and a third stage for removing the photosensitive resist by forming the colored films on the exposed transparent electrodes are executed at least once.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a color filter, and more particularly, to a method of manufacturing a color filter which can be used in a projection type color liquid crystal display device of a single panel type which requires high reliability. It is a thing.

[0002]

2. Description of the Related Art A projection type color liquid crystal display device is a device for irradiating light from the back of a liquid crystal panel to project a color image on a screen.
The panel configuration of this projection type color liquid crystal display device is 1
There are two methods, a single panel method and a three panel method. In the one-panel system, red, green, and blue mosaic color filters are provided so as to correspond to each picture element of the liquid crystal panel. The one-panel system is superior to the three-panel system in terms of downsizing, weight reduction, manufacturing cost reduction, and the like. However, in order to obtain the same brightness as the three-panel system in the one-panel system, it is necessary to irradiate the liquid crystal panel with light having triple the brightness. Therefore, the color filter used for one panel is required to have high reliability.

As a color filter used in a color liquid crystal display device, a gelatin dyeing color filter has been conventionally used, but the reason that gelatin is used as a base material of the color filter and the light resistance of the dye is low. Therefore, it cannot be used as a projection type color filter. Therefore, in order to improve the light resistance of the color filter, a pigment dispersion type color filter in which a pigment is uniformly dispersed in a photosensitive resin has been proposed. This pigment-dispersed color filter uses a pigment instead of the conventional dye, and therefore the light resistance of the pigment itself is improved. However, since the pigment-dispersed color filter uses a polymer resin as a binder, there is a problem in reliability such that the binder is deteriorated under intense light irradiation.

In addition to the above pigment dispersion type color filter, as a means for improving light resistance, an interference color filter in which two kinds of transparent dielectric films having different refractive indexes such as silicon oxide and titanium oxide are alternately laminated. Is proposed. However, it is difficult to apply the interference color filter to a large-sized substrate, and there are essential problems such as the spectral characteristics of the color filter changing due to slight unevenness in the film thickness. Further, the interference color filter has problems in terms of mass production and cost because the forming process is complicated.

The present invention has been made in view of the above problems and is highly reliable and transparent.
An object of the present invention is to provide a color filter that can be used for a projection type color filter of a single panel type.

[0006]

According to the present invention, a colored sol is obtained by subjecting a mixed solution containing a metal alkoxide in which a coloring amount of a pigment is previously dissolved or uniformly dispersed, to a hydrolysis and a dehydration condensation reaction. A method for producing a color filter, which comprises producing a colored gel by applying the colored sol to a transparent substrate and drying it to form a colored gel, and then heating to form a colored film on the transparent substrate. Provided.

Further, according to the present invention, the first step of applying a photosensitive resist on a transparent substrate on which a transparent electrode is formed, and the photosensitive resist is patterned into a desired pattern to form a lower transparent electrode. A step of forming a colored film comprising a second step of exposing and a third step of forming a colored film on the exposed transparent electrode by the method according to claim 1 and removing the photosensitive resist; A method for manufacturing a color filter is provided, which is performed at least once.

The method of the present invention uses an inorganic material (such as glass).
The colored film is manufactured by utilizing the sol-gel method which is one of the synthesizing methods. The sol-gel method starts from a solution of an organic or inorganic compound of a metal, and produces a sol in which fine particles of a metal oxide or a hydroxide are dissolved by hydrolysis and polymerization of the compound in the solution. Gel without impairing sol uniformity (sol solidified in jelly form)
It is a method of converting into a ceramic and further converting into a ceramic.

The present invention makes it possible to form a highly reliable and transparent colored film by utilizing such a sol-gel method as a method for coating a colored film. In the present invention, a metal alkoxide in which a pigment is chemically bonded (hereinafter, referred to as pigment-metal alkoxide) can be used as the metal alkoxide. The metal alkoxide chemically bonded to the pigment is a compound in which one of the alkoxy groups forming the metal alkoxide is substituted with the pigment. When a pigment-metal alkoxide is used, a pigment-metal alkoxide chemically bonded to a coloring amount of a pigment-a mixed solution containing a metal alkoxide previously dissolved or uniformly dispersed is subjected to hydrolysis and dehydration condensation reaction. This produces a colored sol.

As a method of synthesizing the pigment-metal alkoxide used in the present invention, for example, one of the alkoxy groups forming the metal alkoxide is NH ₂ X-group (X
Can be applied to a method of synthesizing a pigment-metal alkoxide by dehydrating and condensing a metal alkoxide substituted with an aliphatic or aromatic hydrocarbon group) and a pigment in the presence of an alcohol under reflux.

Reactions in the synthesis of pigment-metal alkoxide
For example, the formula for forming tetraethyl silicate
One of the coxy groups is NH₂(CH₂)₃A compound substituted by a group
Commercially available γ-aminopropyltriethoxysilane
[NH₂(CH₂)₃Si (OC ₂H_Five)₃] (Shin-Etsu Silicone
Manufactured by K.K.), and the red pigment 1,4-diami
Noanthraquinone-2,3-dicarboxy (3-trieth
Taking xysilano) propylimide as an example
And shown below.

[0012]

[Chemical 1] After the reflux, the synthesized pigment-metal alkoxide can be separated by a method such as filtration after purification by recrystallization in ethanol, for example. As X in the NH ₂ X-group, a lower alkyl group is preferable. A reflux time of 0.5 to 1 hour is suitable. In addition, in the above reaction, 5 to 1 is added to the metal alkoxide in which one of the alkoxy groups forming the metal alkoxide is substituted with an NH ₂ X- group (X is an aliphatic or aromatic hydrocarbon group).
It is expedient to add 0% by weight of pigment.

The metal forming the metal alkoxide used in the present invention includes, for example, silicon and titanium, and silicon is preferable because it is easy to handle. The alkoxy group forming the metal alkoxide may be any aliphatic alkoxy group, and may be a straight chain or branched chain, but a straight chain alkoxy group is preferable. Examples of the straight-chain alkoxy group include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy and the like, and the ethoxy group is preferable. Examples of the branched chain alkoxy group include isopropoxy, 1-methylpropoxy, 1-methylbutoxy,
1-methylpentyloxy, 1-methylhexyloxy, 1-methylheptyloxy, 1-methyloctyloxy, 1-methylnonyloxy, 1-methyldecyloxy, 4-methylpentyloxy, 5-methylhexyloxy and the like. 1-methylpropoxy group is preferred.

As the alcohol used in the present invention, it is preferable to use the same type of alcohol as the alcohol produced by hydrolysis of the metal alkoxide, and it is appropriately selected depending on the metal alkoxide used. The pigment used in the present invention may be any pigment as long as it exhibits a desired color, and examples thereof include azo-based, triphenylmethane-based, quinoline-based, anthraquinone-based, and phthalocyanine-based organic pigments. Among these pigments, anthraquinone-based pigments as red pigments, phthalocyanine-based copper phthalocyanine blue as blue pigments,
As the green pigment, phthalocyanine-based chlorinated copper phthalocyanine green is preferable.

In the present invention, the composition ratio (weight percentage) of the pigment, the metal alkoxide, and the alcohol used for producing the colored sol solution is from 1:30 to 3:30.
5: 35-40 is suitable. Bring the rest to 100 with water. The hydrolysis and dehydration condensation reaction of the metal alkoxide and the pigment-metal alkoxide proceed by adding a hydrolysis catalyst or a substance that causes hydrolysis. Examples of the hydrolysis catalyst or the substance that causes hydrolysis include acids. Examples of the acid to be added include hydrochloric acid, sulfuric acid and the like, and the addition amount thereof may be an amount such that the hydrolysis and the dehydration condensation reaction sufficiently proceed, with respect to the metal alkoxide or the metal alkoxide and the pigment-metal alkoxide. 0.1 to 0.3% by weight is suitable.

The transparent substrate used in the present invention is not particularly limited as long as it is a transparent substrate generally used in manufacturing color filters, and for example, a glass substrate, quartz, plastic or the like can be used. Of these, glass substrates are preferred. Further, in the present invention, the colored film is formed on the transparent substrate, but the colored film may be directly formed on the transparent substrate, the transparent electrode is formed on the transparent substrate, and the colored film is formed thereon. You may. Also,
As the transparent electrode used in the present invention, a transparent electrode generally used in manufacturing a color filter can be applied, and examples thereof include ITO and SnO, and ITO is preferable.

Next, the manufacturing method of the present invention will be described with reference to FIGS.
It will be described based on. First, description will be made with reference to FIG. FIG. 1 is a diagram showing an example of a procedure for forming a colored film on a transparent substrate. First, a pigment is added and dissolved or dispersed in an alcohol / water mixed solution containing a metal alkoxide. This procedure is indicated by a. Then, the acid is added to the solution and refluxed. A reflux time of 1 to 2 hours is suitable. Metal alkoxide by refluxing,
Alternatively, when the pigment-metal alkoxide is used, the hydrolysis and dehydration condensation reaction of the metal alkoxide and the pigment-metal alkoxide proceed, and after the reflux, the colored sol 1 in which the pigment 2 is uniformly dispersed is obtained as shown in b. can get.

Then, this colored sol 1 is applied onto a transparent substrate. As a coating method, a known method can be applied, and examples thereof include a dip coating method and a spinner coating method. Here, application by the dip coating method will be described as an example. First, the transparent substrate 3 is immersed in the colored sol 1. This procedure is indicated by c. The appropriate immersion time is 60 to 120 seconds. When immersing the transparent substrate 3, the temperature of the colored sol 1 is preferably room temperature. Moreover, on the transparent substrate 3 to be used,
A transparent electrode may be formed. After immersion, transparent substrate 3
Is slowly pulled up at a constant speed, the colored sol 1 is uniformly coated on the transparent substrate 3. This procedure is indicated by d. The pulling speed is 0.1 to 0.5 mm
/ Sec is appropriate.

Thereafter, the transparent sol 1 coated with the colored sol 1 is dried to gel the sol, and a colored gel 4 is produced from the colored sol 1 as indicated by e. Room temperature is suitable as the temperature for drying. Drying time is the time until the sol gels, 0.5-1
Time is appropriate. By heating after drying, f
As shown by, the hard and transparent colored film 5 is formed.
A heating temperature of 100 to 150 ° C. is suitable. Moreover, as the heating time, 0.5 to 1 hour is appropriate. The thickness of the colored film thus formed is 0.5 to 1 μm.
m. The color filter is manufactured as described above.

Next, description will be made with reference to FIG. Figure 2
It is the figure which showed an example of the procedure of forming a transparent electrode on a transparent substrate and forming the 1st-3rd colored film in a desired pattern on the transparent electrode. First pattern with desired pattern on transparent electrode
-As a method of forming the third colored film, a known method such as a lift-off method can be applied. First, as indicated by g, the transparent electrode 6 is formed on the transparent substrate 3.
A known method can be applied as the forming method, and examples thereof include a sputtering method and a vapor deposition method. Also,
The appropriate thickness of the transparent electrode 6 is 0.1 to 0.3 μm.

Then, as indicated by h, a photosensitive resist 7 is applied on the transparent electrode 6. A known method can be applied as the coating method, and examples thereof include a spin coating method, a spray method, and a vapor phase coating method. Further, the film thickness of the photosensitive resist 7 is appropriately 1 to 2 μm. After applying the photosensitive resist 7, as shown by i, the photomask 8 is also aligned and exposed, the photosensitive resist 7 is patterned into a desired pattern, baked, and developed, and as shown by j, The transparent electrode 6 is exposed by providing a resist pattern. As a method of forming the pattern of the photosensitive resist 7, a known method can be applied.

Thereafter, as indicated by k, the transparent substrate 3
The first colored sol 9 is applied to the entire surface of the above, dried, and heated to form a hard and transparent colored film. Colored sol generation method, colored sol application method, drying temperature, drying time,
The heating temperature, the heating time and the like are the same as those described with reference to FIG. Then, by removing the photosensitive resist 7 provided under the colored film, the first colored film 10 is formed as indicated by l. As a method for removing the photosensitive resist 7, a known method such as a lift-off method can be applied.

After forming the first colored film 10, the photosensitive resist 7 is applied to the entire surface of the transparent substrate 3 as indicated by m, and the second colored film 11 is formed by repeating the above procedure. To do. After further forming the second colored film 11,
The photosensitive resist 7 is applied to the entire surface of the transparent substrate 3, and the above-described procedure is repeated to form the third colored film 12. In this way, the color filter indicated by n is manufactured.

[0024]

According to the present invention, a mixed solution containing a metal alkoxide in which a coloring amount of a pigment is previously dissolved or uniformly dispersed is subjected to a hydrolysis and a dehydration condensation reaction to obtain a coloring in which fine particles of a metal oxide are dissolved. A sol is produced. The pigment is dissolved or uniformly dispersed in the produced sol. The colored gel is produced by applying the thus-produced colored sol onto a transparent substrate and drying it. By heating the colored gel, further gelation proceeds,
A polymer formed of a metal-oxygen bond is formed, and a colored film in which a pigment is included is formed in the network structure of the polymer formed of a metal-oxygen bond.

Taking the case where tetraethyl silicate [Si (OC ₂ H ₅ ) ₄ ] is used as the metal alkoxide and ethanol is used as the alcohol as an example, the reaction formulas until the production of the colored film is shown below. In the reaction formula below,
Dye represents a pigment, Et is ethyl - group (C ₂ H _5).

[0026]

[Chemical 2] Further, according to the invention, a pigment-metal alkoxide in which a coloring amount of a pigment is chemically bonded-a mixed solution containing a metal alkoxide previously dissolved or uniformly dispersed is subjected to a hydrolysis and a dehydration condensation reaction to obtain a metal A colored sol in which fine particles of a metal oxide (hereinafter, referred to as a pigment-metal oxide) chemically bonded to an oxide and a pigment are dissolved or uniformly dispersed is generated. The colored gel is produced by applying the thus-produced colored sol onto a transparent substrate and drying it. By further heating the colored gel, gelation proceeds further, and a polymer made of a metal-oxygen bond is produced,
A colored film in which a pigment is chemically bonded to the polymer is formed.

Taking the case where tetraethyl silicate [Si (OC ₂ H ₅ ) ₄ ] is used as the metal alkoxide and ethanol is used as the alcohol, the reaction formulas until the production of the colored film is shown below. In the reaction formula below,
_{Dye-Si (OC 2 H 5} ) 3 , the pigment was prepared using tetraethyl silicate as a metal alkoxide - represents a metal alkoxide, Et is ethyl - group (C ₂ H _5).

[0028]

[Chemical 3] The colored film thus formed is such that the pigment is contained in the polymer network formed of metal-oxygen bonds,
Alternatively, since it is chemically bonded to a polymer formed of a metal-oxygen bond, the pigment is not eluted by an organic solvent or the like. Therefore, the color filter thus formed is highly reliable, excellent in performance, and transparent.

Further, according to the present invention, since the color filter is formed in the opening using the patterned photosensitive resist as a mask, the pattern design of the color filter such as a mosaic pattern is free.

[0030]

The present invention will be described in detail based on the following examples. However, the invention is not so limited.

Example 1 Ethanol as an alcohol and 1,4-diaminoanthraquinone-a red pigment of anthraquinone type as a pigment
2,3-Dicarboxy (3-triethoxysilano) propylimide (abbreviated as red pigment in the following description of Example 1) 2, tetraethyl silicate [Si (OC ₂ H ₅ ) ₄ ] as metal alkoxide and transparent The glass substrate 3 was used as the substrate.

100 g of tetraethyl silicate, 12
0 g of ethanol and 100 g of water were put into a flask and mixed, and 5 g of red pigment 2 was added to the mixed solution and dissolved. Then, 1 ml of hydrochloric acid was added to the solution and refluxed for 2 hours. After refluxing for 2 hours, a colored sol 1 in which the red pigment 2 was uniformly dispersed was obtained. Then, the obtained colored sol 1 is kept at room temperature, the glass substrate 3 is dipped in the colored sol 1 for 60 seconds, and the glass substrate 3 is pulled up at a constant speed of 0.5 mm / sec. Allowed to dry for hours. After drying, colored gel 4 was obtained. Furthermore, this glass substrate 3 was heated at 150 ° C. for 1 hour. After heating, a hard and transparent colored film 5 was obtained. The thickness of the colored film 5 is 1
was μm. Thus, a color filter was manufactured.

Example 2 Ethanol as alcohol, anthraquinone type 1,4-diaminoanthraquinone-2,3-dicarboxy (3-triethoxysilano) propylimide as red pigment, and phthalocyanine type chlorinated copper phthalocyanine green as green pigment. A phthalocyanine-based copper phthalocyanine blue was used as a blue pigment, tetraethyl silicate was used as a metal alkoxide, a glass substrate 3 was used as a transparent substrate, and ITO was used as a transparent electrode 6. First, on the glass substrate 3,
The transparent electrode 6 (using ITO) was formed by the sputtering method.
Then, in three flasks, 100 g of tetraethyl silicate, 120 g of ethanol and 100
g water was added and mixed. 5 in 1 mixture
g of 1,4-diaminoanthraquinone-2,3-dicarboxy (3-triethoxysilano) propylimide was added and dissolved, and 5 g of chlorinated copper phthalocyanine green was added to another mixed solution and dispersed. Further, 5 g of copper phthalocyanine blue was added to and dispersed in another mixed solution. Then, 1 ml of hydrochloric acid was added to each solution or dispersion and refluxed for 2 hours to obtain a first colored sol (red) 9, a second colored sol (green) and a second colored sol in which the respective pigments were uniformly dispersed. A colored sol of 3 (blue) was produced.

Next, a colored film of each color was formed in a desired pattern by using the lift-off method. First, a photosensitive resist 7 was applied on the transparent electrode (using ITO) 6 by a spin coating method to a film thickness of 1 μm. then,
A photomask was also used for exposure, the photosensitive resist 7 was patterned into a desired pattern, baked, and developed to expose the transparent electrode (using ITO) 6. After exposing the transparent electrode (using ITO) 6, the first colored sol 9 kept at room temperature is applied to the entire surface of the glass substrate 3, dried at room temperature for 0.5 hour, and heated at 150 ° C. for 1 hour. did.
After heating, the photosensitive resist 7 is removed to remove the first colored film 10.
Was formed.

After forming the first colored film 10, the second colored sol kept at room temperature is applied to the entire surface of the glass substrate 3 and the same operation as described above is repeated to form the second colored film 11. Formed. Further, after forming the second colored film 11, by coating the entire surface of the glass substrate 3 with the third colored sol kept at room temperature and repeating the same operation as described above,
The third colored film 12 was formed. The thickness of these colored films was 1 μm. Thus, a color filter having a desired pattern was manufactured.

[0036]

According to the present invention, a highly reliable and excellent performance transparent color filter can be manufactured by a simple method. Therefore, by using the color filter manufactured by the method of the present invention, it is possible to manufacture a highly reliable, lightweight and compact single panel type projection type color liquid crystal display device at a low cost.

Furthermore, according to the present invention, since the colored film can be formed in a desired pattern and a fine pattern, it is possible to freely design the pattern of the color filter such as a mosaic pattern.

[Brief description of drawings]

FIG. 1 is a diagram showing a procedure for manufacturing a color filter of the present invention.

FIG. 2 is a diagram showing a procedure for manufacturing the color filter of the present invention.

[Explanation of symbols]

1 Colored sol 2 Pigment [1,4-diaminoanthraquinone-2,3-dicarboxy (3-triethoxysilano) propylimide] 3 Transparent substrate (glass substrate) 4 Colored gel 5 Colored film 6 Transparent electrode (ITO) 7 Photosensitization Resist 8 Photomask 9 First colored sol 10 First colored film 11 Second colored film 12 Third colored film

Claims (2)

[Claims] 1. A colored sol is produced by subjecting a mixed solution containing a metal alkoxide, in which a coloring amount of a pigment is previously dissolved or uniformly dispersed, to a hydrolysis and dehydration condensation reaction, and the colored sol is formed on a transparent substrate. A method for producing a color filter, characterized in that a colored gel is produced by applying the composition to a substrate and drying it, and then a colored film is formed on the transparent substrate by heating. 2. A first step of applying a photosensitive resist on a transparent substrate having a transparent electrode formed thereon, and a second step of patterning the photosensitive resist with a desired pattern to expose a lower transparent electrode. And a third step of forming a colored film on the exposed transparent electrode by the method according to claim 1 and removing the photosensitive resist, at least once. A method for manufacturing a characteristic color filter.