JPH08220333A - Production of color filter, color filter obtained by that method, and liquid crystal display panel produced by arranging that color filter - Google Patents

Abstract

PURPOSE: To provide a production method of a color filter by which a liquid crystal filter having high reliability without any defect such as mixing of colors, uneven state of color or void can be produced at a low cost, and to provide a color filter obtd. by this method, and a liquid crystal display panel in which the color filter is assembled. CONSTITUTION: The production method of a color filter includes a process to directly apply an ink coloring agent by ink-jet method in an aperture surrounded by a black matrix 2 formed on a substrate 1 so as to color the aperture 7, a process to form an accepting layer having absorptivity for ink in the colored aperture 7 so as to diffuse the coloring ink 3 into the accepting layer 7 in the aperture, and a process to harden the accepting layer by irradiation of light or heat treatment. The color filter obtd. by this method is used to constitute a liquid crystal display panel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a color filter used in a color television, an in-vehicle television, a personal computer, a personal computer game console, a color filter obtained by the method, and a color filter provided with the color filter. In particular, the present invention relates to a method for manufacturing a color filter using an inkjet recording technique, a color filter obtained by the method, and a liquid crystal display panel configured by arranging the color filter.

[0002]

2. Description of the Related Art In recent years, along with the development of personal computers, especially the development of portable personal computers, the demand for liquid crystal displays has tended to increase.
However, cost reduction is necessary for further widespread use, and in particular, there is an increasing demand for cost reduction of a color filter, which has a heavy weight in terms of cost. Conventionally, a method of satisfying the required characteristics of a color filter has not been established.

The conventional method will be described below. The first method most often used is the staining method. The dyeing method is to first form a water-soluble polymer material, which is a material for dyeing, on a glass substrate, pattern it into a desired shape by a photolithography process, and then immerse the obtained pattern in a dyeing bath. Get a colored pattern. By repeating this three times, R, G, B color filter layers are obtained.

The second method is a pigment dispersion method, which is recently replacing the dyeing method. In this method, first, a photosensitive resin layer in which a pigment is dispersed is formed on a substrate, and this is patterned to obtain a monochromatic pattern. Further, this process is repeated three times to obtain R, G, B color filter layers.

The third method is the electrodeposition method. In this method, a transparent substrate is first patterned on the substrate. Next, the first color is electrodeposited by immersing it in an electrodeposition coating solution containing a pigment, a resin electrolyte solution and the like. This process is repeated three times to form R, G, and B colored layers, and is finally baked.

As a fourth method, a pigment is dispersed in a thermosetting resin, R, G, and B are applied separately by repeating printing three times, and then the resin is thermally cured to form a colored layer. Is. In any method, it is general to form a protective layer on the colored layer.

The common points of these methods are R,
It is necessary to repeat the same process three times in order to color the three colors of G and B, which is costly. Further, there is a problem that the yield decreases as the number of processes increases. Further, in the electrodeposition method, since the pattern shape that can be formed is limited, the current technology cannot be applied to TFTs. In addition, the printing method cannot form fine-pitch patterns because of poor resolution.

As a method for improving these drawbacks, there is a method for producing a color filter using an ink jet method, for example, JP-A-59-75205 and JP-A-63-2.
35901, JP-A-63-294503, JP-A-1
There are proposals such as JP-A-217320 and JP-A-4-123005. These are different from the above-mentioned conventional methods in R, G,
A colored liquid containing each color of B (hereinafter referred to as ink) is jetted onto a filter substrate by a nozzle, and the ink is dried on the filter substrate to form a colored layer. According to this method, the R, G, and B color layers can be formed at one time, and since the amount of the coloring liquid used is not wasted, the productivity can be greatly improved and the cost can be reduced. be able to.

However, this method has a drawback that the ink has a black matrix on the absorber and mixes colors by passing through the boundary between pixels, and the pixel is formed by ejecting liquid ink droplets. Therefore, it is necessary to sufficiently diffuse the ink solvent into the pixels. However, this ink coloring part has a big problem that the image obtained becomes opaque as a result of uneven coloring in the one-light transmitting part depending on the conditions.

[0010]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is to satisfy the requirements of heat resistance, solvent resistance, resolution, etc., which the conventional method has, and also to satisfy the ink jet suitability, and to shorten the process. And a method for manufacturing an inexpensive color filter. In particular, when a color filter is produced by an inkjet method, a method for producing a color filter that can obtain a clear colored light transmitting portion without unevenness in coloring density at different positions in one light transmitting portion, a color filter obtained by the method, and An object is to provide a liquid crystal display panel configured by arranging the color filter.

[0011]

The above object can be achieved by the following means. That is, the present invention is a method of manufacturing a color filter in which a colorant and a black matrix are selectively arranged on a translucent substrate, and an inkjet method is used in a region surrounded by the black matrix on the substrate. A step of ejecting ink to apply a colored ink, a step of forming a receptive layer having ink absorbability on the region in which the colored ink is arranged, and diffusing the colored ink in the receptive layer,
A method for producing a color filter, which comprises a step of curing the receptive layer by light irradiation or heat treatment, wherein the colored ink is a sublimable dye, and the receptive layer is light-irradiated. Alternatively, the ink absorption of the light-irradiated portion is reduced and the resin is cured by light irradiation and heat treatment.

Further, according to the present invention, there is provided a color filter obtained by using the above method and a first substrate on which the color filter is arranged and a second substrate on which the pixel electrode is arranged. The present invention proposes a liquid crystal display panel characterized by being configured by disposing a liquid crystal material.

[0013]

In the present invention, after the ink is applied to the openings of the black matrix, the receiving layer is provided so as to cover the upper surface thereof,
By diffusing the dye in the receiving layer, it is possible to remove the coloring unevenness in the one light transmitting portion.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

In FIG. 1, reference numeral 1 is a substrate. Glass is preferably used as the substrate. The substrate may have transparency and mechanical strength as a color filter for liquid crystal.

In the present invention, a black matrix 2 is provided on a substrate 1 as shown in FIG. 1, and R, G, B, etc. are directly formed in an opening 7 provided in a large number in the black matrix 2 by an ink jet method. Coloring ink 3 is applied.

Next, in the opening 7 to which ink is applied, as shown in FIG.
As described above, a resin such as the below-described resin having ink absorbability is formed with a solvent to form a layer having a thickness of about 0.5 to 2 μm, for example, by a receiving layer-applying roller 4, and the colored ink 3 is evenly distributed in the receiving layer 6. By absorbing and diffusing into the liquid crystal, a color filter for liquid crystal having no color mixture, color unevenness, and color loss can be obtained.
The receiving layer 6 has ink absorbability, and is preferably made of a resin whose light absorbency lowers the ink absorbability of the light-irradiated portion by light irradiation or light irradiation and heat treatment.

As such a resin, an acrylic resin,
Epoxy resins and the like are mentioned, and these are mixed with a solvent such as ethyl cellosolve or N-methylpyrrolidone to prepare a coating agent composition for a receiving layer. Although inks such as R, G, and B can be used in both dye-based and pigment-based inks, they are preferably used because they have the advantage that the sublimable dye diffuses into the receiving layer without heat treatment.

Examples of such sublimable dyes include CI Di
spers Red 59, CI Dispers Bl
ue 56, CI Dispers Green 9 and the like.

The above-mentioned black matrix opening portion provided with a receptive layer having the above-mentioned ink absorbability and having a light-irradiating portion whose ink absorbency is lowered by light irradiation or light irradiation and heat treatment is covered with, for example, FIG. As described above, the colored ink is uniformly absorbed, sublimated, and diffused in the receiving layer by heating if necessary to form a light-transmitting portion, and then the composition is subjected to light irradiation or heat treatment. By curing, a liquid crystal color filter without color mixture, color unevenness, color loss, etc. can be obtained.

Examples of the light irradiating means include a mask aligner, and the light irradiating condition is 10 to 100 mj.
It is about / cm ² . The heat treatment means includes hot press, oven, etc., and the heat treatment conditions are 70 ° C. to 3 ° C.
00 ° C., 10 to 60 minutes. Further, as shown in FIG. 3, a solvent for applying the colored ink to the opening 7 of the substrate 1 to improve the post-leakage property is applied to the opening 7 by the wettability improvement applying device 5, and then the receiving layer having the water-based ink absorbability. 6 through opening 7
As shown in FIG. 4, roll coating is performed to form the receiving layer 6 in the opening 7.
The colored ink 3 may be uniformly absorbed and diffused therein.

Solvents such as cyclohexanol and acetylene can be mentioned as the solvent for improving the ink leakage property.

If desired, a protective layer may be formed on the receiving layer 6. As the protective layer, a photocurable type, a thermosetting type, a photothermal combined type resin material, an inorganic film formed by vapor deposition, sputtering, or the like is used.

The present invention will be described below based on examples.

[0025]

【Example】

Example 1 The coloring material of each color of R, G, and B used in the light transmitting portion of the present invention is a dye-based sublimable ink, CI Disp.
ers Red59, CI DispersBlue5
6, CI Dispers Green 9 was applied to the space between the walls on the substrate provided with the black matrix layer, that is, the light transmitting portion by the inkjet method as shown in FIG. At that time, the ink was hit smaller than the opening, so that the ink was affected by the ejection shape of the inkjet, and a difference in shade of coloring was generated especially in a portion in contact with the black matrix. Therefore, in order to suppress the occurrence of the difference in concentration in the light transmitting portion, the receiving layer formed of a polymer containing hydroxymethacrylate, which has absorptivity for water-based ink, and ethyl cellosolve has a thickness of about 1.4 μm, which is sufficient to absorb the ink. The dye was roll-coated and the dye was uniformly dispersed in the receiving layer (Fig. 2). As a result, the difference in color density in the light transmitting portion of the color filter can be eliminated, and color mixing is suppressed because the black matrix separates the colorants of adjacent pixels.

Next, light irradiation with Deep UV light of 40 mj / cm ² and heat treatment at 200 ° C. were performed in an oven to cure the roll-coated portion of the receptor layer. Next, a liquid crystal display panel was prepared using the color filter formed without providing the protective layer. First, R.I. G. After forming a thin film transistor and a pixel electrode on a glass substrate corresponding to the pattern B, a so-called active matrix substrate provided with a polyimide alignment film was prepared. Then, ITO is formed on the color filter as a transparent conductive film.
And a polyimide alignment film were formed to form a counter substrate. The active matrix substrate and the counter substrate were bonded together via a sealant, and TN (twisted nematic) liquid crystal was sealed in the gap between both substrates. After that, polarizing plates are arranged on both sides of the substrate in which the liquid crystal is sealed, and cold cathode type flat fluorescent lamps are arranged on the active matrix substrate side to form a liquid crystal display device. An image was displayed by inputting a television signal of the NTSC system to the liquid crystal display device thus constructed, and an excellent image could be stably displayed. Although images were displayed for a long time, no troubles such as color mixture, color unevenness, and color loss were observed. A protective layer may be formed if necessary.

As the protective layer, a photocurable type, a thermosetting type, a photothermal combined type resin material, an inorganic film formed by vapor deposition, sputtering or the like can be used, and it has transparency as a color filter. Any material that can withstand the subsequent ITO formation process, alignment film formation process, etc. can be used.

Example 2 After the colored inks of R, G, and B colors similar to those in Example 1 were applied to the openings on the substrate, cyclohexanol was used as a solvent for improving the wettability of the ink and did not cross the black matrix wall. The colorant was applied to a certain degree and the colorant was uniformly filled in the pixels.
Then, a receiving layer made of the same composition as in Example 1 having water-based ink absorbability was roll-coated to a thickness of 1.4 μm,
A color filter free from color mixture and color unevenness was obtained.

[0029]

By adopting the liquid crystal color filter manufacturing method according to the present invention, it is possible to inexpensively manufacture a highly reliable liquid crystal filter free from obstacles such as color mixing and color unevenness.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a state in which ink is applied to an opening of a black matrix in the method of the present invention.

FIG. 2 is a cross-sectional view showing an example of a process of diffusing ink by roll-coating a receiving layer and heating a substrate in the method of the present invention.

FIG. 3 is a cross-sectional view showing an example of a state in which a wettability improver is applied to each pixel in the method of the present invention.

FIG. 4 is a cross-sectional view showing an example of a state in which the receiving layer is roll-coated and the ink is fixed in the method of the present invention.

[Explanation of symbols]

 1 Substrate 2 Black Matrix 3 Colored Ink 4 Color for Receptive Layer Application 5 Wetting Improver Application Device 6 Receptive Layer 7 Opening

Claims (5)

[Claims] 1. A method of manufacturing a color filter comprising a colorant and a black matrix selectively disposed on a translucent substrate, wherein an inkjet method is used in a region surrounded by the black matrix on the substrate. Discharging ink to apply colored ink, forming a receptive layer having ink absorbability on the region where the colored ink is arranged, and diffusing the colored ink in the receptive layer, And a step of curing the receptor layer by light irradiation or heat treatment. 2. The method for manufacturing a color filter according to claim 1, wherein the colored ink is a sublimable dye. 3. The method for producing a color filter according to claim 1, wherein the receiving layer is cured while the ink absorbency of a light-irradiated portion is lowered by light irradiation or light irradiation and heat treatment. 4. A color filter obtained by using the method according to any one of claims 1 to 3. 5. A liquid crystal characterized in that a liquid crystal material is arranged between a first substrate on which the color filter according to claim 4 is arranged and a second substrate on which a pixel electrode is arranged. Display panel.