JPH06265715A - Production of color filter - Google Patents

Abstract

PURPOSE:To provide the production of a color filter which makes a film thickness of a transparent color layer uniform even when a color resist contains much pigment component and shows a big thixotropic property. CONSTITUTION:A color resist 3 essentially consisting of an org. pigment, a water soluble binder resin and a photo-crosslinking agent and formed by blending them so as to satisfy P>V when the weight of the org. pigment is regarded as P and the weight of the water soluble binder resin is regarded as V is applied on a transparent substrate 4 using a roll coater. After coating, the substrate 4 is immediately exposed in air having 60-90% relative humidity and, successively, the color resist 3 is exposed and developed selectively to form a transparent colored layer in picture element regions on the substrate 4 for producing the color filter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a color filter, and more particularly, it is possible to coat a color resist having a large thixotropic property, which contains a large amount of an organic pigment component, on a substrate in a uniform thin film, thereby making it transparent The present invention relates to a method for producing a color filter which can form a uniform thin film of a colored layer and has good color characteristics and excellent spectral characteristics.

[0002]

2. Description of the Related Art A color filter is provided with a transparent substrate such as glass and a pixel portion on the transparent substrate, and the transmitted light thereof has a different color for each pixel (for example, three primary colors of light of red, green and blue).
Its main part is composed of a transparent colored layer that is colored into. This transparent colored layer is formed by uniformly applying a color resist (colored photosensitive resin) containing a pigment of a color corresponding to each color on a transparent substrate, and selectively exposing and developing this. .

By the way, the spectral characteristics of such a color filter are adjusted by the film thickness of the color resist forming the transparent colored layer. When the film thickness is thin, the transmittance is good but the chromaticity is lowered. .

Therefore, in order to manufacture a color filter having good spectral characteristics, it is necessary to form a color resist film having an appropriate film thickness on a transparent substrate. The method by spin coating described in Japanese Patent No. 403, and Japanese Patent Application Laid-Open No. 1-123665.
A method using a roll coater described in Japanese Patent Publication is used.

[0005]

By the way, in the case of a color resist containing a pigment component, the more the pigment component is contained, the thinner the thickness of the transparent colored layer may be. It becomes easier to flatten by decreasing the film thickness, and the common electrode (IT
It is also possible to provide (O etc.) under the transparent colored layer.

However, in the case of application by spin coating, if the color resist contains a large amount of solids such as pigments, the film thickness at the center of rotation is increased due to the effect of thixotropy and the film thickness distribution. There is a problem that occurs. Therefore, at the time of exposure, if the exposure amount is set to a thick portion, the thin portion is overexposed, and conversely, if the exposure amount is set to a thin portion, the thick portion is underexposed and the pattern However, there is a problem in that the flow causes a color variation and a pattern defect. In particular, if the pigment content is large, the influence of the thixotropy becomes large, and it is difficult to apply by the spin method.

On the other hand, in the case of coating with a roll coater,
Since a color resist is once applied to a rubber roller or the like and then this color resist is transferred onto a substrate, a stripe-shaped film thickness distribution is likely to occur in the application direction during this transfer. In order to solve such a problem, for example, Japanese Patent Laid-Open No. 1-1236
Japanese Patent Laid-Open No. 65 proposes a method of applying a coating rod or a coating roller while applying mechanical vibration in the axial direction. In the production of a color filter, first, a fine pattern of the first color is formed, and then, Two
Since the pattern is formed by applying the third color and the third color, there is a problem that the pre-coated pattern may be peeled off by vibrating the roller or the rod.

The present invention has been made by paying attention to such a problem, and the problem is that the above problem does not occur even if a color resist containing a large amount of pigment and having a large thixotropic property is applied. It is to provide a manufacturing method of a color filter.

[0009]

That is, the invention according to claim 1 is a color filter comprising a transparent substrate and a transparent coloring layer which is provided at a pixel portion on the transparent substrate and colors the transmitted light for each pixel. Assuming that the organic pigment, the water-soluble binder resin and the photo-crosslinking agent are the main components, and the weight of the organic pigment is P and the weight of the water-soluble binder resin is V, then P> V. The compounded color resist is applied onto the transparent substrate using a roll coater, and the applied substrate is immediately subjected to relative humidity of 60 to
It is characterized by exposing to 90% air and then selectively exposing and developing the color resist to form the transparent colored layer on the pixel portion of the transparent substrate.

Then, the color resist composed of the above main components is applied onto a substrate by using a roll coater, and immediately after the application, the color resist having a large thixotropic property is dried by exposing it to air having a relative humidity of 60 to 90%. The color resist thin film having a uniform thickness can be formed on the substrate. Therefore, it is possible to form the transparent colored layer having a uniform and thin film thickness on the substrate. Further, by including a large amount of pigment in the color resist, it is possible to obtain a color filter having a thinner film, excellent transmittance and chromaticity, and excellent color characteristics.

Here, the roll of the roll coater used in the invention according to claim 1 is for supplying the color resist to the substrate once and then applying the color resist on the substrate. Rubber, SU
S, etc.), the number of rolls, the rotation speed, the rotation direction, etc. may be arbitrary and are not particularly limited.

The means for exposing the substrate immediately after the application of the color resist to the air having a relative humidity of 60 to 90% is not particularly limited, but it can be performed by spraying moisture using a humidifier or the like. Relative humidity in air is 60 ~
The limitation to 90% is that when the relative humidity is less than 60%, the effect of delaying the drying rate cannot be obtained, while when the relative humidity exceeds 90%, the water content is too high, and the water is a liquid on the color resist. This is because they tend to become drops. The temperature is 2
About 0 to 35 ° C is preferable.

Next, the color resist applied in claim 1 has an organic pigment, a water-soluble binder resin and a photo-crosslinking agent as main components.

The organic pigments include phthalocyanine pigments, quinacridone pigments, dioxazine pigments, azo lake pigments, insoluble azo pigments, condensed azo pigments, perylene pigments, isoindolinone pigments, and anthraquinone pigments. , Thioindico type pigments and the like can be applied.

These organic pigments may be dispersed in water, polyvinyl alcohol, polyethylene glycol, polyethylene glycol alkyl ether and the like in a ball mill, a sand mill or the like, and mixed with the following water-soluble binder resin or photo-crosslinking agent for use.

As the water-soluble binder resin, acrylic acid, methacrylic acid, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, dimethylaminopropyl acrylate, dimethylaminopropyl methacrylate, polyethylene glycol, polyvinyl alcohol. A mixture or polymer selected from acrylamide, acrylamide, methoxymethylacrylamide and the like can be applied.

This water-soluble binder resin has a molecular weight of 10
The range of 00 to 4000 is preferable. Molecular weight 100
This is because if it is less than 0, it easily flows even when photocrosslinked, and if it has a molecular weight of more than 4000, the pigment dispersibility is poor. Furthermore, the molecular weight of the binder resin is 1
By setting 000 to 4000, as described later,
When the weight of the organic pigment is P and the weight of the binder resin is V, it is possible to disperse the pigment at a compounding ratio of P> V.

Examples of the photocrosslinking agent include diazo resins, diazonium salts, polyfunctional azides and the like.

The color resist of the present invention is formulated so that P> V, where P is the weight of the organic pigment and V is the weight of the water-soluble binder resin. By setting the weight mixing ratio of the organic pigment and the binder resin in this way, it is possible to reduce the thickness of the transparent colored layer, which has been difficult so far, and it is possible to form a transparent colored layer having a thickness of 1 μm or less. As described above, it is possible to obtain a color filter having good color characteristics, which is not inferior in chromaticity even with a thin film.

Further, examples of the transparent substrate applicable to the invention according to claim 1 include glass, plastic and the like.

[0021]

According to the invention of claim 1, when P is the weight of the organic pigment and V is the weight of the water-soluble binder resin, the main component is the organic pigment, the water-soluble binder resin and the photo-crosslinking agent. A color resist formulated so as to be> V is coated on a transparent substrate using a roll coater, and the substrate after coating is immediately exposed to air having a relative humidity of 60 to 90%, and then the color resist is coated. The transparent colored layer is formed on the pixel portion of the transparent substrate by selectively exposing and developing.

That is, the color resist is coated on the substrate by using a roll coater, and immediately after that, the relative humidity 60 is applied.
By exposing to 90% to 90% of air, the drying speed of the color resist is delayed, the coated surface maintains fluidity, and a color resist layer having a uniform film thickness can be formed on the substrate by its leveling property. This makes it possible to form a transparent colored layer having a uniform film thickness on the substrate.

Furthermore, by including a large amount of pigment in the compounding ratio of P> V in the color resist, it becomes possible to reduce the thickness of the transparent colored layer, which has been difficult so far, and the film thickness is 1 μm.
It is possible to form a transparent colored layer having a thickness of m or less, and thus it is possible to obtain a color filter having good color characteristics and not inferior in chromaticity even with a thin film.

[0024]

EXAMPLES Examples of the present invention will be described in detail below.

First, as a water-soluble binder resin, 2-
80% by weight of hydroxyethylmethacrylic acid, 4% by weight of dimethylaminopropylmethacrylamide, 2% by weight of methacrylamide and 14% by weight of methoxymethylacrylamide were polymerized to synthesize a binder resin having a molecular weight of 2000, and a photocrosslinking agent was added to the binder resin. Was mixed with 10% by weight of diazo resin to obtain a photosensitive resin.

On the other hand, permanent red was used as a red organic pigment, chlorinated cyanine green was used as a green organic pigment, and a mixture of destabilized cyanine blue and dioxazine violet was applied as a blue organic pigment. Red, green and blue pigment liquids were prepared by dispersing in water, polyvinyl alcohol and polyethylene glycol monoolein ether, respectively. The average particle diameter of the pigment in each organic pigment was 0.02 μm.

Next, the pigment solid content in these pigment liquids: the resin content in the pigment liquid and the solid content in the photosensitive resin are mixed at a ratio of 6: 4, respectively, and red, green and blue are mixed. To prepare a color resist solution.

Then, a glass substrate having a light-shielding layer made of a chromium thin film between each pixel is used as a transparent substrate, and a red color resist solution is first applied to this substrate by a roll coater shown in FIG. It was applied so as to have a thickness of 0.5 μm, and immediately after the application, air having a relative humidity of 80% (temperature of 22 ° C.) was blown for 3 minutes using a humidifier to perform leveling. Then, it was dried at an air temperature of 60 ° C., exposed to ultraviolet light through a photomask having a transparent portion at a predetermined position corresponding to a pixel, developed with a 1% malic acid solution, and patterned to form a red transparent colored layer.

Here, FIG. 1 shows a schematic configuration diagram of a roll coater used in this embodiment.
It is composed of a comma roll 1, a roll 2, and a humidifier 5 in which a humidification inlet 7 and a humidification outlet 8 are opened in a cover 6. Then, the color resist liquid supplied between the comma rolls 1 and 2 is applied onto the roll 2 and transferred onto the glass substrate 4 which is conveyed in the arrow direction.
The glass 1 substrate 4 to which the color resist liquid has been transferred is conveyed into the cover 6, and is humidified immediately after the transfer by the air containing the humidity supplied from the humidification inlet 7 of the humidifier 5 provided in the cover 6. It has become.

After forming the above-mentioned red transparent colored layer, a green transparent colored layer and a blue transparent colored layer are sequentially patterned to provide three transparent colored layers of red, green and blue with a diagonal of 10 inches (= 25.4 cm). ) Was produced.

The spectral characteristics of the obtained color filter were measured and the results are shown in Table 1 below.

[0032]

[Table 1] The average thickness of the transparent colored layer pattern of the obtained color filter was 0.5 μm, and there was no color variation and good spectral characteristics were exhibited.

[Comparative Example 1] In the example, the relative humidity was 8
A transparent colored layer was provided on a glass substrate in the same manner as in Example except that an atmosphere having a temperature of 22 ° C. and a relative humidity of 50% was passed instead of blowing 0% of air to prepare a color filter.

The spectral characteristics of the obtained color filter were measured. The results are shown in Table 2.

[0035]

[Table 2] The thickness of the film thickness of the transparent colored layer pattern of the obtained color filter appeared as a color variation as it was.

[Comparative Example 2] An attempt was made to produce a color filter by the spin method using the same color resist as in the Example. However, since the film thickness at the center of rotation of the substrate was too thick and the exposure was insufficient, The pattern of the part flowed and the transparent colored layer could not be obtained.

[0037]

According to the invention of claim 1, the color resist is coated on a substrate by using a roll coater and immediately thereafter exposed to air having a relative humidity of 60 to 90%. It is possible to form a color resist layer having a uniform film thickness by delaying the coating, keeping the coated surface fluid, and leveling itself. Therefore, it becomes possible to form a transparent colored layer having a uniform film thickness on the substrate. In addition, by including a large amount of pigment in the color resist, it is possible to manufacture a color filter having a thinner film, good transmittance and chromaticity, and excellent color characteristics.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a roll coater applied in an example.

[Explanation of symbols]

 1 Comma roll 2 Roll 3 Color resist 4 Substrate 5 Humidifier 6 Cover 7 Humidification inlet 8 Humidification outlet

Claims (1)

[Claims] 1. A method for producing a color filter comprising a transparent substrate and a transparent colored layer which is provided at a pixel portion on the transparent substrate and colors the transmitted light for each pixel, wherein an organic pigment, a water-soluble binder resin and light are used. When the weight of the organic pigment is P and the weight of the water-soluble binder resin is V and the main component is a cross-linking agent, a color resist is mixed so that P> V, and a roll coater is applied on the transparent substrate. And the substrate after coating is immediately subjected to a relative humidity of 6
A method for producing a color filter, which comprises exposing the color resist to 0 to 90% of air and then selectively exposing and developing the color resist to form the transparent colored layer on the pixel portion of the transparent substrate.