JP2001242316A - Color filter and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color filter comprising pixel parts formed on a photocatalyst containing layer with an inkjet method, and exerting no adverse influence on a liquid crystal layer even in the case of being used for a color liquid crystal display device. SOLUTION: The color filter is at least provided with a transparent substrate, the photocatalyst containing layer arranged on the transparent substrate, containing at least a photocatalyst and a binder and having wettability varied by exposure so as to lower a contact angle with a liquid, and the pixel parts arranged on the photocatalyst containing layer with the inkjet method, having plural colors with a specified pattern and with specified distances. The provided color filter is characterized by having a coated part formed on the distance between the pixel parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a color filter suitable for a color liquid crystal device, which is obtained by coloring a pixel portion by an ink jet method, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, with the development of personal computers, especially portable personal computers, the demand for liquid crystal devices, especially color liquid crystal devices, has been increasing. However, since the color liquid crystal device is expensive, there is an increasing demand for cost reduction, and in particular, there is a high demand for cost reduction for color filters having high specific gravity.

Such a color filter usually has three primary color patterns of red (R), green (G), and blue (B), and has electrodes corresponding to respective pixels of R, G, and B. Is turned on and off, the liquid crystal operates as a shutter, and light passes through each pixel of R, G, and B to perform color display.

In the conventional method of manufacturing a color filter, the same process is generally repeated three times in order to color R, G, and B colors. There is a problem that the yield is reduced due to repetition. As a method of avoiding such a problem and obtaining a color filter at low cost, various methods of forming a colored layer (pixel portion) by spraying a colored ink by an inkjet method have been proposed (JP-A-59-75205).
JP, JP-A-9-203803, JP-A-8-2803
30314, and JP-A-8-227012). However, none of these methods is necessarily satisfactory in terms of the process and the quality of the obtained color filter.

The present inventors have proposed a method using a photocatalyst-containing layer as a method for forming a colored layer (pixel portion) by spraying a colored ink by an ink jet method (Japanese Patent Laid-Open No. 11-337726). According to this method, it is possible to easily form a pattern having different wettability by exposure, and by forming a colored layer (pixel portion) thereon,
An inexpensive and high-quality color filter can be provided.

However, since such a color filter has a photocatalyst containing layer containing a photocatalyst, when a color liquid crystal display device is formed using this color filter, the photocatalyst containing layer and the liquid crystal are separated. May come in contact. In such a case, it cannot be denied that there is a possibility that a problem such as deterioration of the liquid crystal itself occurs due to the action of the photocatalyst contained in the photocatalyst containing layer. It is also conceivable that contaminants contained in the photocatalyst-containing layer are eluted into the liquid crystal and the display quality of the liquid crystal layer is reduced.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and is directed to a color filter in which a pixel portion is formed on a photocatalyst-containing layer by an ink jet method in a color liquid crystal display device. Even in such a case, the main object is to provide a color filter that does not adversely affect the liquid crystal layer.

[0008]

In order to achieve the above object, according to the present invention, there is provided a liquid crystal display device, comprising: a transparent substrate; and at least a photocatalyst and a binder provided on the transparent substrate. A photocatalyst-containing layer which is a layer whose wettability changes so that the contact angle of the photocatalyst is reduced, and pixels provided on the photocatalyst-containing layer in a predetermined pattern of a plurality of colors by an inkjet method and with a predetermined gap. A color filter having at least a pixel portion, wherein a coating portion is formed in a gap between the pixel portions.

In the color filter of the present invention, since the covering portion is formed in the gap between the pixel portions, the photocatalyst containing layer is not exposed at this portion. When a liquid crystal display device is manufactured, there is no possibility that the liquid crystal layer and the photocatalyst containing layer are in direct contact with each other. Therefore, there is no possibility that the liquid crystal material in the liquid crystal layer is deteriorated by the photocatalyst, and a color liquid crystal display device with good display quality can be provided. Furthermore, since the coating portion as described above is formed, a liquid crystal layer contaminant that causes a problem with the liquid crystal material in the liquid crystal layer when it elutes into the liquid crystal layer in the photocatalyst containing layer is mixed. Also, such liquid crystal layer contaminants do not elute into the liquid crystal layer, and there is no possibility that the display performance of the liquid crystal layer will be adversely affected. In addition, since the covering portion is formed in the gap between the pixel portions, unevenness in this portion is reduced, and for example, when forming a relatively thin layer such as a transparent electrode layer or an alignment film, the unevenness is reduced. There are few problems caused by it.

In the first aspect of the present invention, as described in the second aspect, the covering portion is formed also on a photocatalyst-containing layer provided outside a display area constituted by the pixel portion. Is preferred. In a color filter using a photocatalyst-containing layer, the photocatalyst-containing layer may be formed outside the display region formed by the pixel portion. Also in such a case, from the viewpoint of preventing the above-mentioned adverse effect on the liquid crystal material, it is preferable to form the covering portion also on the photocatalyst-containing layer existing in the region outside the display region.

Further, in the color filter according to the first or second aspect, the height of the covering portion may be the same as the height of the pixel portion. preferable. The shape of the covering portion is not particularly limited as long as the photocatalyst containing layer does not directly contact the liquid crystal material in the liquid crystal layer, but the covering portion is formed so as to have the same height as the pixel portion. This is because the display area formed by the pixel portion becomes a smooth plane, and the subsequent formation of the transparent electrode layer, the alignment layer, and the like is facilitated.

According to a fourth aspect of the present invention, there is provided a transparent substrate, provided on the transparent substrate, including at least a photocatalyst and a binder, and contacting a liquid by exposure. In a color filter having at least a photocatalyst-containing layer that is a layer whose wettability changes so that the angle is reduced, and a pixel portion provided with a plurality of colors in a predetermined pattern by an inkjet method on the photocatalyst-containing layer, A color filter, wherein the coating portion is formed on a photocatalyst-containing layer provided outside a display region constituted by the portion.

Depending on the type of the color filter, the display region formed by the pixel portion is configured so that the photocatalyst-containing layer does not adversely affect the liquid crystal layer. The photocatalyst containing layer formed on the outside may adversely affect the liquid crystal material in the liquid crystal layer. In such a case, it is necessary to form a coating layer only on the photocatalyst-containing layer outside the display region, and by forming the coating layer only on the portion outside the display region as described above, This can prevent adverse effects on the liquid crystal material in the liquid crystal layer.

In the color filter according to any one of the first to fourth aspects of the present invention, as described in the fifth aspect, the covering portion does not adversely affect the liquid crystal material. Is preferably formed. The covering portion is basically formed so that the photocatalyst-containing layer and the liquid crystal material do not come into direct contact with each other. There is no particular limitation on the material used, but the covering portion itself has an adverse effect on the liquid crystal material. This is because the effect of improving the display quality of the liquid crystal layer as described above by forming the covering portion is reduced.

Further, in the color filter according to any one of the first to fifth aspects, as described in the sixth aspect, the surface tension is larger than the critical surface tension of the pixel portion. It is preferable that the coating portion is formed using a paint having the following formula. Thus, the surface tension of the coating for forming the coating for forming the coating,
When the critical surface tension of the pixel portion is larger than the critical surface tension, the coating material for forming the covering portion has a contact angle with respect to the pixel portion of more than 0 degree. Therefore, when the coating material for forming the coating portion is applied between the pixel portions, the coating material for forming the coating portion can be easily applied only between the pixel portions without spreading to the surface of the pixel portion. Further, since the contact angle is larger than 0 degree, the coating material for forming the covering portion can be applied to a level equal to or higher than the height of the pixel portion. Therefore, even when curing shrinkage or the like is taken into account, it is easy to obtain the covering portion on the same plane as the pixel portion, and the display region formed by the pixel portion can be made flat.

In the invention described in any one of the first to sixth aspects, as described in the seventh aspect, a light-shielding portion is formed on the transparent substrate. It may be a color filter in which the photocatalyst-containing layer is formed on a transparent substrate on which a portion is formed.
The color filter of the present invention can provide the same effect regardless of whether the light-shielding portion (black matrix) is formed on the color filter side or formed on the counter electrode substrate side. It is.

According to any one of the first to seventh aspects,
In the color filter described in claim 1,
Item 8. As described in Item 8, the photocatalyst is titanium oxide (T
iO _Two), Zinc oxide (ZnO), tin oxide (SnO)_Two),
Strontium titanate (SrTiO_Three), Oxidation tongue
Stainless (WO_Three), Bismuth oxide (Bi)_TwoO_Three),and
Iron oxide (Fe_TwoO_Three) Or one or more selected from
It is preferable that the substance is
Like titanium oxide (TiO_Two)
No. This is because the band gap energy of titanium oxide is
Highly effective as a photocatalyst and chemically stable
It is non-toxic and easy to obtain.

Further, in the color filter according to any one of the first to ninth aspects, the binder may be a Y filter.
_n SiX _(4-n) (where Y represents an alkyl group, a fluoroalkyl group, a vinyl group, an amino group, a phenyl group or an epoxy group, X represents an alkoxyl group or a halogen. It is preferably an organopolysiloxane which is one or more hydrolytic condensates or co-hydrolytic condensates of a silicon compound represented by the following formula: This is because the binder of the photocatalyst-containing layer is preferably a polymer compound that is not easily decomposed by the action of the photocatalyst.

In the present invention, as described in claim 11, (1) a photocatalyst which is a layer containing at least a photocatalyst and a binder and having a wettability changed so that a contact angle with a liquid is reduced by exposure. Forming a content layer on a transparent substrate; and (2) forming a pixel portion on a photocatalyst containing layer provided on the transparent substrate, the pixel portion forming portion being a portion for forming a pixel portion;
Forming a pixel portion having a predetermined pattern and a predetermined gap by applying a pattern of energy to form a pixel portion exposure portion, and coloring the pixel portion exposure portion into a plurality of colors by an inkjet method; (3) A method of manufacturing a color filter, comprising at least a step of forming a coating portion using a coating material for forming a coating portion in a gap between the pixel portions.

By forming the covering portion by such a process, the portion where the photocatalyst containing layer which may come into contact with the liquid crystal material can be easily covered can be easily covered. A color filter capable of obtaining a high-quality color liquid crystal display device can be manufactured.

According to the eleventh aspect of the present invention,
It is preferable that the step of forming the coating portion using the coating material for the coating portion is performed by a method of applying the coating material for the coating portion by a nozzle discharge method. By applying the coating material for the coating portion by the nozzle discharge method in this manner, it is possible to selectively apply only the gap between the pixel portions, for example, thereby providing a difference in wettability by exposing the photocatalyst containing layer to light. This is because there are advantages in that the coating can be applied even without the coating, and there is a low possibility that the coating material for forming the coating portion remains on the pixel portion.

In the method for manufacturing a color filter according to the eleventh or twelfth aspect, as described in the thirteenth aspect, the surface tension of the coating material for forming the coating portion is higher than the critical surface tension of the pixel portion. Is also preferably large.
If the surface tension of the coating material for forming the coating portion is larger than the critical surface tension of the pixel portion, the coating material for forming the coating portion can be easily applied only to the gap between the pixels for the same reason as in the sixth aspect. This is because the display region formed by the pixel portion can be made flat.

Further, in the invention described in any one of the eleventh to thirteenth aspects, as described in the fourteenth aspect, before the step of forming the covering portion, the pixel portion is formed. It is preferable that the method further includes a step of exposing the gap between the pixel portions so that the critical surface tension of the photocatalyst-containing layer existing in the gap between the pixel portions becomes larger than the critical surface tension of the pixel portion. Since the gap between the pixel portions is a concave portion, it is possible to apply the coating material for forming the covering portion regardless of the wettability on the photocatalyst containing layer. However, if the exposure is performed so that the critical surface tension of the photocatalyst-containing layer becomes larger than the critical surface tension of the pixel portion, the wettability to the coating material for forming the coating portion is higher in the photocatalyst-containing layer than in the pixel portion. This makes it possible to more accurately apply the coating material for forming the coating portion between the pixel portions on the photocatalyst containing layer between the pixel portions.

[0024] According to the invention described in any one of claims 11 to 14, claim 15
As described in above, before the step of forming the photocatalyst-containing layer on the transparent substrate, the method may include a step of forming a light-shielding portion on the transparent substrate. This is because the method for manufacturing the color filter of the present invention is not limited to the presence or absence of the light shielding portion.

According to a second aspect of the present invention, there is provided a color liquid crystal display device comprising the color filter according to any one of the first to tenth aspects. provide. Such a color liquid crystal display device can prevent the liquid crystal material in the liquid crystal layer from being adversely affected by the photocatalyst-containing layer, so that a color liquid crystal display device having excellent display quality can be obtained.

[0026]

DETAILED DESCRIPTION OF THE INVENTION 1. Hereinafter, the color filter of the present invention will be described in detail. The color filter of the present invention is a transparent substrate, a photocatalyst containing layer provided on the transparent substrate, containing at least a photocatalyst and a binder, and changing the wettability so that the contact angle with a liquid is reduced by exposure. A color filter having at least a layer and a pixel portion provided on the photocatalyst-containing layer in a predetermined pattern with a plurality of colors by an ink jet method, and having a predetermined gap. Are characterized by the formation of

According to the present invention, since the covering portion is formed in the gap between the pixel portions, the following effects can be obtained. That is, the color liquid crystal display device
Generally, it is formed by arranging a color filter and a counter electrode substrate on the color filter at a predetermined interval, and sealing a liquid crystal material between the color filter and the counter electrode substrate to form a liquid crystal layer. Various layers such as a transparent electrode layer, an alignment layer, and a protective layer may be formed on the surface on the color filter side, but it is also possible that no layer is formed at all in the gap between the pixel portions. In such a case, the above-mentioned liquid crystal material in the liquid crystal layer comes into direct contact with the photocatalyst containing layer. If the liquid crystal material and the photocatalyst containing layer come into contact with each other and some light such as a backlight is irradiated on the contact area, the liquid crystal material in the liquid crystal layer may be degraded by the action of the photocatalyst, resulting in the display of the liquid crystal layer. The quality will be reduced. In such a case, by forming the covering portion in the gap between the pixel portions, the contact between the liquid crystal material and the photocatalyst-containing layer can be prevented, and the above-described disadvantage such as deterioration in display quality of the liquid crystal layer can be prevented. The likelihood of occurrence can be reduced.

Even when a thin film such as a transparent electrode is formed in the gap between the pixel portions, for example, when a liquid crystal contaminant which adversely affects the liquid crystal material is contained in the photocatalyst containing layer. Even if it is covered with such a thin film, there is a possibility that it will permeate through the thin film and elute into the liquid crystal material in the liquid crystal layer. In such a case, the display quality of the liquid crystal layer is also reduced. Also in this case, by providing the coating portion with a predetermined thickness, it is possible to prevent the liquid crystal contaminants in the photocatalyst containing layer from being eluted into the liquid crystal layer, and to prevent problems such as deterioration in display quality of the liquid crystal layer. Can be.

Further, the presence of a gap between the pixel portions means that the display area formed by the pixel portions has irregularities. As described above, a functional thin film having a predetermined function, such as a transparent electrode layer or an alignment film, must be formed in this display area in some cases. At this time, if there are large irregularities in the display area, it may be difficult to form such a functional thin film. In this case, the functional thin film can be easily formed by providing the covering portion in the gap between the pixel portions to reduce and flatten the unevenness of the entire display region.

Next, such a color filter of the present invention will be specifically described with reference to the drawings. FIG. 1 shows an example of the color filter of the present invention. This color filter comprises a transparent substrate 1, a photocatalyst containing layer 2 formed on one surface thereof, and a pixel portion 3 formed on the photocatalyst containing layer 2. A light-shielding portion 4 is formed above the portion located between the pixel portions 3 and a portion outside the display area A including the pixel portions. The pixel section 3 is formed on the photocatalyst-containing layer 2 in a predetermined pattern with a predetermined gap. A coating section 5 is formed in the gap, and a display area A formed by the pixel section 3 is formed. The coating portion 5 is also formed on the photocatalyst-containing layer 2 existing in a portion outside the.
Hereinafter, each of these components will be individually described.

(Covering Part) As described above, the feature of the present invention is that the covering part 5 is formed in the gap between the pixel parts 3 as shown in FIG. 1, but the present invention is not limited to this. For example, as shown in FIG. 1, when the photocatalyst containing layer 2 is formed outside the display area A constituted by the pixel portions 3, if the covering portion 5 is only between the pixel portions 3, In addition, it is preferable that it is formed also on the photocatalyst containing layer formed outside the display area A.

As described above, when the photocatalyst-containing layer is formed outside the display area and a color liquid crystal display device is formed using such a color filter, the liquid crystal material in the liquid crystal layer is formed outside the display area. This is because the layer comes into contact with the photocatalyst-containing layer, and the liquid crystal material is deteriorated by the action of the photocatalyst.

Further, the present invention includes a color filter in which, when the photocatalyst-containing layer is formed outside the display area, the coating portion is formed only on the photocatalyst-containing layer formed outside the display area. It is a thing. For example, when the pixel portion is formed over the entire display region without a gap between the pixel portions, or both the pixel portion and the light shielding portion are formed on the photocatalyst containing layer, and the display region includes the photocatalyst containing When the layer is not exposed to the outside, furthermore, in the display region, the transparent electrode and the alignment layer are formed, so that the photocatalyst containing layer is not exposed. However, since these layers are not formed outside the display region, the photocatalyst containing layer is not formed. This is because, in the case where is exposed, it is necessary to form a coating portion only on the photocatalyst-containing layer formed outside the display region.

In the present invention, the shape of the coating portion is not particularly limited as long as it can cover the photocatalyst-containing layer in principle so as not to be exposed. However, when the covering portion is formed between the pixel portions, if the height of the covering portion formed in the gap between the pixel portions is formed to be the same height as the height of the pixel portion, it is possible to configure the pixel portion. The displayed display area can be made flat. If the display region can be flattened in this way, when a transparent electrode layer or an alignment layer is formed on the display region thereafter,
It can be easily formed. Therefore, it is preferable that the height of the covering portion formed in the gap between the pixel portions is formed to be the same as the height of the pixel portion.

The same height as used herein means ± 0.3
It means having a height difference within μm.

In the present invention, the material forming the coating portion is
The material is not particularly limited as long as it can cover the photocatalyst-containing layer, and any material can be used. However, the coating may directly contact the liquid crystal material in the liquid crystal layer. At this time, if the coating is a material having a bad influence on the liquid crystal material, the display quality of the obtained color liquid crystal display device is deteriorated. Will be. Therefore, it is preferable that the covering portion is formed of a material that does not adversely affect the liquid crystal material.

As a material which does not adversely affect the liquid crystal material, a material containing no ionic organic or inorganic substance can be used.

Further, the material for forming the coating portion in the present invention has a surface tension of the coating material for forming the coating portion used for forming the coating portion that is larger than the critical surface tension of the pixel portion. It is preferred that This is for the following reason.

That is, when the coating portion is formed in the gap between the pixel portions, the coating can be formed by adhering the coating material for forming the coating portion to the concave portion of the gap between the pixel portions, so that the surface tension is particularly limited. Not something. However, since the coating for forming the coating portion is accurately applied to the photocatalyst-containing layer present between the pixel portions, the contact angle of the coating for forming the coating portion with respect to the pixel portion is larger than the contact angle on the photocatalyst-containing layer.
That is, it is clear that the better the wettability on the photocatalyst-containing layer is, the easier the coating is. At this time, if the surface tension of the coating material for forming the coating portion is equal to or less than the critical surface tension of the pixel portion, the contact angle of the coating material for forming the coating portion with respect to the pixel portion becomes 0 degrees. This makes it impossible to make the contact angle larger than the contact angle on the photocatalyst-containing layer. On the other hand, the surface tension of the coating for forming the coating portion is
In the case where the coating has a surface tension higher than the critical surface tension of the pixel portion, the contact angle of the coating material for forming the coating portion on the pixel portion has an angle of at least more than 0 degrees. If the coating for forming a coating portion has a contact angle of more than 0 degrees with respect to the pixel portion, the critical surface tension is increased by exposing the photocatalyst-containing layer to the photocatalyst-containing layer. The contact angle on the upper side can be made smaller than the contact angle on the pixel section, and the coating material for forming the covering section can be applied to the photocatalyst-containing layer with high accuracy as described above. For this reason, it is preferable that the surface tension of the coating material for forming the covering portion is larger than the critical surface tension of the pixel portion.

As described above, in order to make the display area flat, it is preferable that the covering portion has the same height as that of the pixel portion. In order to achieve the same height, it is generally necessary to apply the coating material for forming the coating portion between the pixel portions so as to be higher than the pixel portion when applying the coating material for forming the coating portion due to curing shrinkage and the like. . At this time, if the surface tension of the coating for forming the coating portion is not larger than the critical surface tension of the pixel portion, the contact angle of the coating for forming the coating portion with respect to the pixel portion is 0 degree, and the contact angle between the pixel portions is higher than the pixel portion. The coating for forming the coating cannot be adhered. From this point as well, it is preferable that the surface tension of the coating material for forming the covering portion is larger than the critical surface tension of the pixel portion.

The specific surface tension of the coating material for forming a coating portion in the present invention is preferably 21 to 70 mN / m, since the critical surface tension of a general pixel portion is about 20 mN / m to 50 mN / m. And particularly preferably 3
In the range of 0-70 mN / m, most preferably 50-70 mN / m.
It is in the range of mN / m.

The surface tension of the coating for forming the coating can be adjusted by selecting the solvent and the composition of the coating.

(Transparent Substrate) As shown in FIG. 1, the color filter of the present invention comprises a photocatalyst containing layer 2
The pixel portion 3 and the covering portion 5 described above are formed at least. Such a transparent substrate includes:
There is no particular limitation as long as it has been conventionally used for a color filter. For example, a transparent rigid material having no flexibility such as quartz glass, Pyrex glass, or a synthetic quartz plate, or a transparent flexible material having flexibility such as a transparent resin film or an optical resin plate can be used. Of these, Corning 7059 glass is a material having a low coefficient of thermal expansion, excellent dimensional stability and workability in high-temperature heat treatment, and is an alkali-free glass containing no alkali component in the glass. It is suitable for a color filter for a color liquid crystal display device according to the method. In the present invention, a transparent substrate is usually used as a transparent substrate, but a reflective substrate or a substrate colored white can also be used. Further, as the transparent substrate, a substrate which has been subjected to surface treatment for preventing alkali elution, imparting a gas barrier property or other purposes as necessary may be used.

(Photocatalyst-Containing Layer) In the color filter of the present invention, a photocatalyst-containing layer 2 is formed on the transparent substrate 1 as shown in FIG. Such a photocatalyst-containing layer used in the present invention has at least a photocatalyst and a binder, and is a layer whose wettability changes so that the contact angle with a liquid is reduced by exposure. The photocatalyst containing layer in the present invention,
Although not particularly limited, the layer is mainly used for forming a pixel portion. That is, since the photocatalyst-containing layer is such that the wettability changes so that the contact angle with the liquid is reduced by exposure, for example, by performing pattern exposure so as to expose only the portion where the pixel portion is formed, The wettability of a portion where a pixel portion is formed can be easily reduced, and an ink-philic region having a small contact angle with a liquid can be obtained. Therefore, by applying the ink by the ink-jet method to the ink-philic region as described above, the pixel portion is formed only in a portion where the pixel portion is easily formed due to a difference in wettability with an unexposed ink-repellent region. Forming ink can be applied. Thereafter, the pixel portion can be easily formed by curing the applied ink. As described above, by forming the pixel portion using the photocatalyst-containing layer, the manufacturing cost can be significantly reduced, and the cost of a color liquid crystal display device or the like as a final product can be significantly reduced. .

Here, the ink-philic region is a region having a small contact angle with the liquid, and is a region having good wettability with the ink for ink-jet forming the pixel portion. The ink-repellent region is a region having a large contact angle with a liquid, and is a region having poor wettability with ink for ink-jet forming a pixel portion.

The photocatalyst-containing layer has a contact angle of not less than 10 degrees with a liquid having a surface tension of 40 mN / m, preferably a contact angle of not less than 10 degrees with a liquid having a surface tension of 30 mN / m in the unexposed portion. In particular, the contact angle with a liquid having a surface tension of 20 mN / m is preferably 10 degrees or more. This is because the non-exposed portion is a portion that requires ink repellency in the present invention. Therefore, when the contact angle with the liquid is small, the ink repellency is not sufficient, and the pixel portion is not formed. This is because there is a possibility that the ink for ink jetting may remain in a region where the pixel portion is not formed, and the pixel portion cannot be accurately formed.

When the photocatalyst-containing layer is exposed to light, the contact angle with the liquid decreases, and the contact angle with the liquid having a surface tension of 40 mN / m is less than 10 degrees, preferably 50 mN / m.
/ M of liquid has a contact angle of 10 degrees or less, especially a surface tension of 60
It is preferable that the layer has a contact angle with the liquid of mN / m of 10 degrees or less. If the contact angle of the exposed portion with the liquid is high, the spread of the ink of the ink jet system for forming the pixel portion in the exposed portion may be inferior,
This is because color loss or the like may occur in the pixel portion.
Further, even when the coating for forming the coating portion is applied, the lower the contact angle with the liquid in the exposed portion, the easier the application of the coating for forming the coating portion.

Here, the contact angle with a liquid is measured by using a contact angle measuring device (CA-Z type, manufactured by Kyowa Interface Science Co., Ltd.) to measure the contact angle with a liquid having various surface tensions (micrometer). 30 seconds after dropping the droplet from the syringe), and the result or the result is graphed. In this measurement, wetting index standard solutions manufactured by Junsei Chemical Co., Ltd. were used as liquids having various surface tensions.

The photocatalyst-containing layer used in the present invention is composed of at least a photocatalyst and a binder. With such a configuration, the type of the binder before the exposure can be determined by selecting the type of the binder. This is because adjustments such as reducing the critical surface tension and increasing the critical surface tension after exposure can be easily performed. Specifically, the photocatalyst oxidizes organic groups and additives that are part of the binder,
Using the action of decomposition or the like, the wettability of the exposed portion is changed to make it ink-philic, and a large difference in wettability with the non-exposed portion can be caused. Since the photocatalyst-containing layer has the binder as described above, receptivity (ink-affinity) in an exposed portion with ink-jet ink forming a pixel portion or repulsion (ink-repellency) in an unexposed portion is improved. As a result, a color filter having good quality and advantageous in cost can be obtained.

In the present invention, when the photocatalyst-containing layer further contains fluorine, and the fluorine content on the surface of the photocatalyst-containing layer is such that the photocatalyst-containing layer is exposed to light or the like, The photocatalyst-containing layer may be formed so that the photocatalyst-containing layer is reduced by the action as compared to before the exposure.

In a color filter having such characteristics, it is possible to easily form a pattern composed of a portion having a low fluorine content by pattern exposure. Here, fluorine has an extremely low surface energy, so that the surface of a substance containing a large amount of fluorine has a smaller critical surface tension. Therefore, the critical surface tension of the portion having a low fluorine content is larger than the critical surface tension of the portion having a high fluorine content. This means that a portion having a low fluorine content is an ink-philic region compared to a portion having a high fluorine content. Therefore, forming a pattern composed of a portion having a smaller fluorine content than the surrounding surface forms a pattern of the ink-philic region within the ink-repellent region.

Therefore, when such a photocatalyst-containing layer is used, the pattern of the ink-philic region can be easily formed in the ink-repellent region by pattern exposure. It is possible to easily form a pixel portion and the like only on a pixel portion, and a color filter with good quality can be obtained. In addition, since the ink-affinity region can be made by exposure, the coating is easily and accurately applied to the photocatalyst-containing layer in the gap between the pixel portions by performing exposure when forming the coating. be able to.

As described above, the fluorine content in the fluorine-containing photocatalyst containing layer is determined by the fact that the fluorine content in the low ink-affinity ink-formed region formed by exposure is the unexposed portion. 100 fluorine content
In this case, it is preferably 10 or less, more preferably 5 or less, and particularly preferably 1 or less.

By setting it within such a range, a large difference can be produced in the ink affinity between the exposed portion and the unexposed portion. Therefore, by forming a pixel portion or the like in such a photocatalyst-containing layer, it becomes possible to accurately form a pixel portion or a covering portion only in an ink-philic region having a reduced fluorine content, and a color filter with high accuracy. Is obtained. In addition, this reduction rate is based on weight.

For the measurement of the fluorine content in the photocatalyst-containing layer, various methods generally used can be used. For example, X-ray photoelectron spectroscopy (X-ray Phot spectroscopy) can be used.
oelectron Spectroscopy, ESCA (Electron Spectroscop
y for Chemical Analysis). ), Any method capable of quantitatively measuring the amount of fluorine on the surface, such as X-ray fluorescence analysis and mass spectrometry.

The photocatalyst used in the present invention includes, for example, titanium oxide (TiO ₂ ), zinc oxide (ZnO), tin oxide (SnO ₂ ), strontium titanate (SrTiO ₃ ), and tungsten oxide (W) which are known as optical semiconductors.
O ₃ ), bismuth oxide (Bi ₂ O ₃ ), and iron oxide (F
e ₂ O ₃ ), and one or more of them may be used in combination.

In the present invention, titanium oxide is particularly preferably used because it has a high band gap energy, is chemically stable, has no toxicity, and is easily available. Titanium oxide includes anatase type and rutile type, and both can be used in the present invention, but anatase type titanium oxide is preferable. Anatase type titanium oxide has an excitation wavelength of 380 nm or less.

Examples of such anatase-type titanium oxide include, for example, anatase-type titania sol of peptized hydrochloride (STS-02 (average particle size: 7 nm) manufactured by Ishihara Sangyo Co., Ltd.)
ST-K01 manufactured by Ishihara Sangyo Co., Ltd., anatase titania sol of nitric acid peptization type (TA-15 (average particle size: 12 nm) manufactured by Nissan Chemical Industries, Ltd.) and the like can be mentioned.

The smaller the particle size of the photocatalyst is, the more effective the photocatalytic reaction takes place. The average particle size is preferably 50 nm or less, more preferably 20 nm or less. In addition, the smaller the particle size of the photocatalyst is, the smaller the surface roughness of the formed photocatalyst-containing layer is. It is preferable that the particle size of the photocatalyst exceeds 100 nm. It is not preferable because the ink repellency of the non-exposed portion of the containing layer is reduced, and the expression of ink affinity in the exposed portion is insufficient.

In the color filter of the present invention, as described above, the surface of the photocatalyst-containing layer contains fluorine, and the surface of the photocatalyst-containing layer is subjected to pattern exposure to reduce the fluorine content on the surface of the photocatalyst-containing layer. A color filter obtained by forming a pattern of an ink-philic region in the ink-repellent region and forming a pixel portion, a covering portion, and the like on the pattern may be used. Even in this case, it is preferable to use the titanium dioxide as described above as the photocatalyst. However, when titanium dioxide is used in this way, the content of fluorine contained in the photocatalyst containing layer is determined by X-ray photoelectron. Quantitative analysis by spectroscopy shows that when the titanium (Ti) element is 100, the fluorine (F) element is 500 or more,
Preferably, fluorine (F) element is contained on the surface of the photocatalyst-containing layer at a ratio of preferably 800 or more, particularly preferably 1200 or more.

When fluorine (F) is contained in the photocatalyst-containing layer to this extent, the critical surface tension on the photocatalyst-containing layer can be sufficiently reduced, so that the ink repellency on the surface can be ensured. This is because the difference in wettability between the exposed ink-philic region and the pattern portion in which the fluorine content has been reduced by exposure can be increased, and the quality of the finally obtained color filter can be improved. .

Further, in such a color filter, the fluorine content in the parent ink region formed by pattern exposure is preferably 50 or less when the titanium (Ti) element is 100, and the fluorine content is preferably 50 or less. Is preferably 20 or less, more preferably 10 or less.

If the content of fluorine in the photocatalyst-containing layer can be reduced to this extent, sufficient ink-affinity for forming a pixel portion or the like can be obtained. The difference in wettability makes it possible to form a pixel portion and the like with high accuracy, and to obtain a high-quality color filter.

In the present invention, the binder used for the photocatalyst-containing layer preferably has a high binding energy such that the main skeleton is not decomposed by the photoexcitation of the photocatalyst. For example, (1) chloro or alkoxy by a sol-gel reaction or the like is used. Examples thereof include organopolysiloxanes that exhibit great strength by hydrolyzing and polycondensing silanes and the like, and (2) organopolysiloxanes obtained by crosslinking reactive silicones having excellent water repellency and oil repellency.

In the case of the above (1), the general formula: Y _n SiX _(4-n) (where Y represents an alkyl group, a fluoroalkyl group, a vinyl group, an amino group, a phenyl group or an epoxy group,
X represents an alkoxyl group, an acetyl group or a halogen. n is an integer from 0 to 3. ) Is preferably an organopolysiloxane that is one or more hydrolytic condensates or cohydrolytic condensates of the silicon compound represented by the formula (1). Here, the carbon number of the group represented by Y is preferably in the range of 1 to 20, and the alkoxy group represented by X is preferably a methoxy group, an ethoxy group, a propoxy group, or a butoxy group. preferable.

Specifically, methyltrichlorosilane, methyltribromosilane, methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltri-t-butoxysilane; ethyltrichlorosilane, ethyltribromosilane, ethyltrichlorosilane Methoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, ethyltri-t-butoxysilane; n
-Propyltrichlorosilane, n-propyltribromosilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-propyltriisopropoxysilane, n-propyltri-t-butoxysilane; n-
Hexyltrichlorosilane, n-hexyltribromosilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, n-hexyltriisopropoxysilane, n-hexyltri-t-butoxysilane; n-decyltrichlorosilane, n-decyltribromosilane,
n-decyltrimethoxysilane, n-decyltriethoxysilane, n-decyltriisopropoxysilane, n-
Decyltri-t-butoxysilane; n-octadecyltrichlorosilane, n-octadecyltribromosilane, n
-Octadecyltrimethoxysilane, n-octadecyltriethoxysilane, n-octadecyltriisopropoxysilane, n-octadecyltri-t-butoxysilane; phenyltrichlorosilane, phenyltribromosilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyl Triisopropoxysilane, phenyltri-t-butoxysilane; tetrachlorosilane, tetrabromosilane, tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, dimethoxydiethoxysilane; dimethyldichlorosilane, dimethyldibromosilane, dimethyldimethoxysilane , Dimethyldiethoxysilane; diphenyldichlorosilane, diphenyldibromosilane, diphenyldimethoxysilane, diphenyldiethoxysilane Phenyl methyldichlorosilane,
Phenylmethyldibromosilane, phenylmethyldimethoxysilane, phenylmethyldiethoxysilane; trichlorohydrosilane, tribromohydrosilane, trimethoxyhydrosilane, triethoxyhydrosilane, triisopropoxyhydrosilane, tri-t-butoxyhydrosilane; vinyltrichlorosilane, vinyltribromo Silane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, vinyltrit
-Butoxysilane; trifluoropropyltrichlorosilane, trifluoropropyltribromosilane, trifluoropropyltrimethoxysilane, trifluoropropyltriethoxysilane, trifluoropropyltriisopropoxysilane, trifluoropropyltri-t-butoxysilane; γ- Glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ
Glycidoxypropyltriisopropoxysilane, γ
-Glycidoxypropyltri-t-butoxysilane; γ-
Methacryloxypropylmethyldimethoxysilane, γ
-Methacryloxypropylmethyldiethoxysilane,
γ-methacryloxypropyltrimethoxysilane, γ
-Methacryloxypropyltriethoxysilane, γ-
Methacryloxypropyltriisopropoxysilane,
γ-methacryloxypropyltri-t-butoxysilane; γ-aminopropylmethyldimethoxysilane, γ-
Aminopropylmethyldiethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltriisopropoxysilane, γ-aminopropyltri-t-butoxysilane;
γ-mercaptopropylmethyldimethoxysilane, γ-
Mercaptopropylmethyldiethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropyltriisopropoxysilane, γ-mercaptopropyltri-t-butoxysilane; β- (3,4-epoxy Cyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane; and their partial hydrolysates; and mixtures thereof, can be used.

As the binder, particularly, a polysiloxane containing a fluoroalkyl group can be preferably used. Specifically, one or more hydrocondensation products of the following fluoroalkylsilanes, co-hydrolysis Examples thereof include condensates, and those generally known as a fluorine-based silane coupling agent can be used.

CF ₃ (CF ₂ ) ₃ CH ₂ CH ₂ Si (OC
H ₃ ) ₃ ; CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ Si (OC
H ₃ ) ₃ ; CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si (OC
H ₃ ) ₃ ; CF ₃ (CF ₂ ) ₉ CH ₂ CH ₂ Si (OC
_{H 3) 3; (CF 3} ) 2 CF (CF 2) 4 CH 2 CH 2 Si (O
CH ₃ ) ₃ ; (CF ₃ ) ₂ CF (CF ₂ ) ₆ CH ₂ CH ₂ Si
(OCH ₃ ) ₃ ; (CF ₃ ) ₂ CF (CF ₂ ) ₈ CH ₂ CH ₂ S
i (OCH ₃ ) ₃ ; CF ₃ (C ₆ H ₄ ) C ₂ H ₄ Si (OC
_{H 3) 3; CF 3 (} CF 2) 3 (C 6 H 4) C 2 H 4 Si (OC
H ₃ ) ₃ ; CF ₃ (CF ₂ ) ₅ (C ₆ H ₄ ) C ₂ H ₄ Si (OC
_{H 3) 3; CF 3 (} CF 2) 7 (C 6 H 4) C 2 H 4 Si (OC
H ₃ ) ₃ ; CF ₃ (CF ₂ ) ₃ CH ₂ CH ₂ SiCH ₃ (OCH
₃ ) ₂ ; CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ SiCH ₃ (OC
H ₃ ) ₂ ; CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ SiCH ₃ (OCH
₃ ) ₂ ; CF ₃ (CF ₂ ) ₉ CH ₂ CH ₂ SiCH ₃ (OC
H ₃ ) ₂ ; (CF ₃ ) ₂ CF (CF ₂ ) ₄ CH ₂ CH ₂ SiCH
₃ (OCH ₃ ) ₂ ; (CF ₃ ) ₂ CF (CF ₂ ) ₆ CH ₂ CH ₂
Si CH ₃ (OCH ₃ ) ₂ ; (CF ₃ ) ₂ CF (CF ₂ ) ₈
CH ₂ CH ₂ Si CH ₃ (OCH ₃ ) ₂ ; CF ₃ (C ₆ H ₄ )
C ₂ H ₄ SiCH ₃ (OCH ₃ ) ₂ ; CF ₃ (CF ₂ ) ₃ (C ₆
H ₄ ) C ₂ H ₄ SiCH ₃ (OCH ₃ ) ₂ ; CF ₃ (CF ₂ ) ₅
(C ₆ H ₄ ) C ₂ H ₄ SiCH ₃ (OCH ₃ ) ₂ ; CF ₃ (CF
_{2) 7 (C 6 H 4} ) C 2 H 4 SiCH 3 (OCH 3) 2; CF
₃ (CF ₂ ) ₃ CH ₂ CH ₂ Si (OCH ₂ CH ₃ ) ₃ ; CF ₃
(CF ₂ ) ₅ CH ₂ CH ₂ Si (OCH ₂ CH ₃ ) ₃ ; CF
₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si (OCH ₂ CH ₃ ) ₃ ; CF ₃
(CF ₂ ) ₉ CH ₂ CH ₂ Si (OCH ₂ CH ₃ ) ₃ ; CF
₃ (CF ₂ ) ₇ SO ₂ N (C ₂ H ₅ ) C ₂ H ₄ CH ₂ Si (OC
H ₃ ) ₃

By using a polysiloxane containing a fluoroalkyl group as described above as a binder,
The ink repellency of the non-exposed part of the photocatalyst containing layer is greatly improved,
It exhibits a function of preventing the adhesion of the ink for the inkjet system for forming the pixel portion.

The reactive silicone of the above (2) includes a compound having a skeleton represented by the following general formula.

[0071]

Embedded image

Here, n is an integer of 2 or more, and R ¹ ,
R ² is a substituted or unsubstituted alkyl, alkenyl, aryl or cyanoalkyl group having 1 to 10 carbon atoms, and 40% or less of the whole is vinyl, phenyl or halogenated phenyl in a molar ratio. Further, those in which R ¹ and R ² are methyl groups are preferred because the surface energy is minimized, and the molar ratio of the methyl groups is preferably 60% or more. Further, the chain terminal or the side chain has at least one or more reactive group such as a hydroxyl group in the molecular chain.

Further, a stable organosilicon compound which does not undergo a cross-linking reaction, such as dimethylpolysiloxane, may be mixed with the above-mentioned organopolysiloxane in a binder.

In the present invention, the photocatalyst-containing layer may contain a surfactant in addition to the above-mentioned photocatalyst and binder. More specifically, NIKK manufactured by Nikko Chemicals Co., Ltd.
Hydrocarbons such as OLBL, BC, BO, and BB series, ZONYL FSN and FSO manufactured by DuPont, Surflon S-141 and 145 manufactured by Asahi Glass Co., Ltd., and Megafax F-141 manufactured by Dainippon Ink and Chemicals, Inc. 144, Neos Co., Ltd. manufactured by Fategent F-200, F251, Daikin Industries, Ltd. Unidyne DS-401, 402,
Examples include fluorine-based or silicone-based nonionic surfactants such as Florad FC-170 and 176 manufactured by 3M Co., Ltd., and a cationic surfactant, an anionic surfactant, and an amphoteric surfactant are used. You can also.

Further, in addition to the above-mentioned surfactants, the photocatalyst-containing layer contains polyvinyl alcohol, unsaturated polyester, acrylic resin, polyethylene, diallyl phthalate, ethylene propylene diene monomer, epoxy resin, phenol resin, polyurethane, melamine resin. Oligomers such as polycarbonate, polyvinyl chloride, polyamide, polyimide, styrene butadiene rubber, chloroprene rubber, polypropylene, polybutylene, polystyrene, polyvinyl acetate, polyester, polybutadiene, polybenzimidazole, polyacrylonitrile, epichlorohydrin, polysulfide, polyisoprene, A polymer or the like can be contained.

The content of the photocatalyst in the photocatalyst containing layer is 5 to 5.
It can be set in the range of 60% by weight, preferably 20 to 40% by weight. Further, the thickness of the photocatalyst-containing layer is 0.1 mm.
It is preferably in the range of 05 to 10 μm.

The photocatalyst-containing layer can be formed by dispersing a photocatalyst and a binder, if necessary, in a solvent together with other additives to prepare a coating solution, and applying the coating solution. As the solvent to be used, alcohol-based organic solvents such as ethanol and isopropanol are preferable. The coating can be performed by a known coating method such as spin coating, spray coating, dip coating, roll coating, and bead coating. When an ultraviolet-curable component is contained as a binder, the photocatalyst-containing layer can be formed by irradiating ultraviolet rays and performing a curing treatment.

(Pixel part) As shown in FIG. 1, the color filter of the present invention has a plurality of colors, usually red (R), green (G),
The pixel portion 3 is formed so that the three colors of blue and blue (B) have a predetermined pattern and a predetermined gap.

Here, the predetermined pattern is a pattern usually used in a color filter, and specific examples include a mosaic pattern, a triangle pattern, a stripe pattern and the like. In addition, the predetermined interval here refers to an interval of about 1 to 100 μm.

The ink jet type ink for forming such a pixel portion is roughly classified into aqueous and oily inks. In the present invention, any ink can be used. Water-based aqueous inks are preferred.

In the aqueous ink used in the present invention, water alone or a mixed solvent of water and a water-soluble organic solvent can be used as a solvent. On the other hand, oil-based inks based on high-boiling solvents are preferably used in order to prevent clogging of the head. Known pigments and dyes are widely used as the colorant used in such an ink-jet type ink. Further, a resin soluble or insoluble in a solvent may be contained for improving dispersibility and fixing property. In addition, surfactants such as nonionic surfactants, cationic surfactants, and amphoteric surfactants; preservatives; fungicides; pH adjusters; defoamers; ultraviolet absorbers; viscosity adjusters: surface tension adjusters; May be added as needed.

Further, ordinary ink jet type inks cannot contain a large amount of binder resin due to low appropriate viscosity, but the colorant itself has fixing ability by granulating the colorant particles in the ink by wrapping the resin. Can be made. Such an ink can also be used in the present invention. Further, a so-called hot melt ink or UV curable ink can be used.

In the present invention, it is particularly preferable to use UV curable ink. By using a UV curable ink, after forming a pixel portion by coloring with an ink jet method, the ink can be quickly cured by irradiating UV, and can be immediately sent to the next step. Therefore, a color filter can be efficiently manufactured.

Such a UV curable ink contains a prepolymer, a monomer, a photoinitiator and a colorant as main components. As the prepolymer, polyester acrylate, polyurethane acrylate, epoxy acrylate, polyether acrylate, oligoacrylate, alkyd acrylate, polyol acrylate,
Any of prepolymers such as silicon acrylate can be used without any particular limitation.

Examples of the monomer include vinyl monomers such as styrene and vinyl acetate; monofunctional acrylic monomers such as n-hexyl acrylate and phenoxyethyl acrylate; diethylene glycol diacrylate, 1,6-hexanediol diacrylate, hydroxypiperate ester neopentyl Polyfunctional acrylic monomers such as glycol diacrylate, trimethylolpropane triacrylate, and dipentaerythrol hexaacrylate can be used. The above prepolymer and monomer may be used alone or in combination of two or more.

The photopolymerization initiators include isobutyl benzoin ether, isopropyl benzoin ether, benzoin ethyl ether, benzoin methyl ether, 1-phenyl-1,2-propadion-2-oxime, 2,2-
Dimethoxy-2-phenylacetophenone, benzyl,
Hydroxycyclohexylphenyl ketone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzophenone, chlorothioxanthone, 2-chlorothioxanthone, isopropylthioxanthone, 2-methylthioxanthone, chlorine-substituted benzophenone, halogen-substituted Those which can obtain desired curing characteristics and recording characteristics can be selected and used from alkyl-allyl ketones and the like. In addition, if necessary, a photoinitiating auxiliary such as an aliphatic amine or an aromatic amine; a photosensitizer such as thioxanthone may be added.

In the method of forming such a pixel portion, first, as described above, pattern exposure is performed on the photocatalyst-containing layer so as to form an ink-philic region having the same pattern as the pattern of the pixel portion to be formed. Will be applied. Next, an ink for forming a pixel portion is applied to the ink-philic region by an inkjet method. Then, the pixel portion can be formed by curing the pixel portion forming ink.

(Light Shielding Portion) The color filter of the present invention includes both those having a light shielding portion and those having no light shielding portion. For example, FIG. 1 shows an example in which a light shielding portion 4 is formed. The light shielding portion 4 is formed on a transparent substrate 1, and the photocatalyst containing layer 2 is further covered so as to cover the light shielding portion 4.
Are formed. At this time, the light-shielding part 4 includes a light-shielding part 4a in the display area formed between the pixel parts 3 in the display area A, and a light-shielding part 4b outside the display area formed outside the display area A formed by the pixel part 3. Are usually formed.

The color filter of the present invention is not limited to the one in which the light-shielding portion 4 is formed on the transparent substrate 1 as shown in FIG. Is also included. When the light-shielding portion is formed on the photocatalyst-containing layer as described above, the photocatalyst-containing layer is not exposed by the pixel portion and the light-shielding portion in a display region usually formed from the pixel portion. In such a case, as described above, the covering portion may be formed only on the photocatalyst-containing layer formed outside the display region.

As shown in FIG. 1, when the light shielding portion 4 is formed on the transparent substrate 1 and the photocatalyst containing layer is formed so as to cover the light shielding portion 4, the light shielding portion is not limited to this. Is usually formed by forming a metal thin film of chromium or the like having a thickness of about 1000 to 2000 ° by a sputtering method, a vacuum evaporation method or the like, and patterning the thin film. As this patterning method, an ordinary patterning method such as sputtering can be used.

When a light-shielding portion is formed on the photocatalyst-containing layer by utilizing the difference in wettability similarly to the pixel portion, the light-shielding portion is
Although not limited thereto, it is formed of a layer in which light-shielding particles such as carbon fine particles, metal oxides, inorganic pigments, and organic pigments are contained in a resin binder. Examples of the resin binder used in this case include polyimide resin, acrylic resin, epoxy resin, polyacrylamide, polyvinyl alcohol, gelatin, casein, cellulose, or a mixture of two or more resins, a photosensitive resin, For example, an O / W emulsion type resin composition, for example, an emulsion of reactive silicone can be used. The thickness of such a resin light-shielding portion can be set within a range of 0.5 to 10 μm.

(Others) The color filter of the present invention includes:
Other members may be formed as necessary, and specifically, a transparent electrode layer, an alignment layer, a protective layer, a columnar member functioning as a spacer, or the like may be formed.

[0093] 2. Method for producing a color filter Next, a method for manufacturing a color filter of the present invention. The method for producing a color filter of the present invention comprises: (1) disposing a photocatalyst-containing layer containing at least a photocatalyst and a binder and changing the wettability by exposure so that the contact angle with a liquid is reduced on a transparent substrate; Forming, and (2) patternwise irradiating energy to a pixel portion forming portion, which is a portion for forming a pixel portion on the photocatalyst containing layer provided on the transparent substrate, to form a pixel portion exposing portion, Forming a pixel portion having a predetermined pattern and a predetermined gap by coloring the exposure portion for the pixel portion into a plurality of colors by an inkjet method; and (3) forming a coating portion in the gap between the pixel portions. And forming a coating portion using a paint. Hereinafter, each of the above steps will be described.

FIG. 2 is for explaining each step in an example of the method for manufacturing a color filter of the present invention.
In this example, first, the transparent substrate 1 is formed by a conventional method.
The light-shielding part 4 (the light-shielding part 4a in the display area and the light-shielding part 4b outside the display area) is formed thereon. The method for manufacturing the light-shielding portion 4 is not particularly limited. For example, as described above, a thickness of 1000 to 1000
A method of forming a metal thin film of chromium or the like having a thickness of about 2000 ° and patterning the thin film may be used.

Next, a photocatalyst-containing layer 2 is formed on the transparent substrate 1 on which the light-shielding portion 4 is formed (FIG. 2A). This photocatalyst containing layer 2 is formed by dispersing the photocatalyst and the binder as described above together with other additives in a solvent as needed to prepare a coating solution, applying the coating solution, and then subjecting the coating solution to hydrolysis, It is formed by advancing the polycondensation reaction to firmly fix the photocatalyst in the binder. The solvent used is preferably an alcoholic organic solvent such as ethanol or isopropyl alcohol, and the coating can be performed by a known coating method such as spin coating, spray coating, dip coating, roll coating, or bead coating.

The transparent substrate 1 on which the photocatalyst containing layer 2 is formed is irradiated with light 6 such as ultraviolet light by a photomask 7 in a pattern. Thereby, the pixel portion forming portion on the photocatalyst containing layer 2 where the pixel portion is formed,
By the action of the photocatalyst in the photocatalyst containing layer 2, the exposure portion 8 for the pixel portion is formed as an ink-philic region (FIG. 2B).
The type of pattern irradiation is not limited to the one using a photomask, but may be the one using drawing irradiation using a laser or the like.

The pixel section forming ink is jetted into the pixel section exposing section 8 thus formed by using an ink jet device or the like, and is colored red, green, and blue, respectively. At this time, since the inside of the exposure unit 8 for the pixel unit is an ink-philic region having a small contact angle with the liquid due to the exposure as described above, the ink for forming the pixel unit ejected from the inkjet apparatus is used for the pixel unit. It spreads uniformly in the exposure unit 8.
In addition, since the region of the photocatalyst-containing layer that has not been exposed is an ink-repellent region, the ink is repelled and removed in this region.

The ink-jet apparatus used in the present invention is not particularly limited, but includes a method of continuously ejecting charged ink and controlling by a magnetic field, and a method of intermittently ejecting ink using a piezoelectric element. Alternatively, an ink jet apparatus using various methods such as a method in which ink is heated and intermittently ejected by utilizing foaming thereof can be used.

Thus, the pixel portion 3 is formed by solidifying the ink adhered in the pixel portion exposure portion 8 (FIG. 2C). In the present invention, the solidification of the ink is performed by various methods depending on the type of the ink used. For example, in the case of a water-soluble ink, the water is removed by heating or the like to be solidified.

In consideration of the ink solidification step, the ink used in the present invention is preferably a UV curable ink. This is because the UV curable ink can quickly solidify the ink by irradiating the UV, so that the manufacturing time of the color filter can be shortened.

As described above, since the ink in the pixel portion exposure portion 8 is uniformly spread, when the ink is solidified in this way, the pixel portion 3 without color omission or color unevenness can be formed. .

Next, the entire surface on which the pixel portion 3 is formed is exposed. As a result, the portion where the photocatalyst containing layer 2 is exposed, that is, the photocatalyst containing layer 2 between the pixel portions 3 and outside the display region is exposed to become a coating portion exposure portion 9 which is an ink-philic region (FIG. 2 ( d)).

Here, it is preferable that the exposed portion 9 for the covering portion is exposed so that its critical surface tension is larger than the critical surface tension of the pixel portion. That is, if the exposure is performed such that the critical surface tension of the exposed portion 9 for the covering portion, which is the photocatalyst-containing layer, is larger than the critical surface tension on the pixel portion 3,
When the coating portion forming paint is applied between the pixel portions 3, the wettability to the coating portion forming paint described later is better in the coating portion exposing portion 9 than in the pixel portion 3. This is because it is possible to more accurately apply the photocatalyst containing layer between the three layers.

Then, in the coating portion exposure section 9, the coating material
Is adhered to the gap between the pixel portions 3 and to the covering portion exposure portion 9 outside the display region. At this time, since the inside of the exposed portion 9 for the covering portion becomes an ink-philic region having a small contact angle with the liquid due to the exposure as described above, the coating material 11 Spreads evenly in the exposed portion 9 for the covering portion.

The method of applying the coating 11 is as follows.
The application is not limited to the above-described ink-jet method, and may be applied by utilizing a difference in wettability by various methods such as a commonly used dip coating.
However, for example, it is possible to selectively apply only the gaps between the pixel portions, thereby applying the photocatalyst-containing layer without exposing the photocatalyst-containing layer to a wettability difference. It is preferable to use a nozzle discharge method because the possibility that the paint remains is low. Examples of such a nozzle discharge method include a micro syringe, a dispenser, an ink jet, a method in which a coating for forming a coating portion is ejected from a needle tip by an external stimulus such as an electric field, and an element using a vibration element such as a piezo element vibrated by the external stimulus. How to fly the coating for forming the coating part more,
It is possible to use a method of attaching the coating for forming the coating portion attached to the needle tip to the surface of the photocatalyst-containing layer, but among others, it is possible to mass-produce by the ink jet method, which is advantageous in terms of cost, etc. preferable.

It is preferable that the surface tension of the coating material 11 used for forming the covering portion is larger than the critical surface tension of the pixel portion 3. This is because, as described above, when the surface tension of the coating portion forming paint 11 is larger than the critical surface tension of the pixel portion 3, the coating portion forming paint 11 is larger than 0 degrees with respect to the pixel portion 3. It will have a contact angle. For this reason, when the coating portion forming paint 11 is applied to the coating portion exposure portion 9 between the pixel portions 3, the back surface does not overlap with the light shielding portion 4 on the surface of the pixel portion 3, that is, on the pixel portion 3. It does not spread to the part where the light passes. This is because the coating material 11 for forming the covering portion can be easily applied only between the pixel portions 3 without adversely affecting the display performance of the pixel portions 3.

Then, by curing the coating material 11 for forming the coating portion, the coating portion 5 is provided between the pixel portions 3 and on the photocatalyst containing layer 2 outside the display area.
(E)).

In consideration of the curing step here, it is preferable that the coating portion forming paint 11 used for the covering portion 5 like the pixel portion 3 is also a UV curing type paint.

FIG. 2 shows an example in which the light shielding portion 4 is formed. However, the method for manufacturing the color filter of the present invention is not limited to this. That is, a method of manufacturing a color filter having no light shielding portion may be used.

Further, in the example shown in FIG. 2, after forming the pixel portion, the exposure portion 9 for the covering portion is formed by exposing, and the covering portion 5 is formed here. The present invention is not limited to this, and may be a manufacturing method that does not perform the above-described exposure. That is, when the covering portion is formed on the photocatalyst-containing layer between the pixel portions, since there is a concave portion between the pixel portions (see, for example, FIG. 2C), ink is attached to the concave portion by an ink jet method or the like. By doing so, it is also possible to form a covering portion. In this case, it is not necessary to expose the photocatalyst-containing layer. However, considering that it is easier to form a coating portion when a difference in wettability is provided, the critical surface tension of the photocatalyst-containing layer is lower than the critical surface tension of the pixel portion as in the example shown in FIG. The exposure is preferably performed so as to be larger than the surface tension.

[0111] 3. Color liquid crystal display device A color liquid crystal display device is formed by combining the thus obtained color filter with a counter electrode substrate facing the color filter and sealing a liquid crystal compound therebetween. The color liquid crystal display device obtained in this way had the advantage of the color filter of the present invention, that is, high display quality without adversely affecting the liquid crystal material in the liquid crystal layer.

The present invention is not limited to the above embodiment. The above embodiment is an exemplification, and has substantially the same configuration as the technical idea described in the scope of the claims of the present invention. It is included in the technical scope of the invention.

For example, in the above description, the wettability of the photocatalyst-containing layer is changed by exposure. However, the term “exposure” as used herein does not indicate only visible light exposure, It is meant to include all the irradiation of energy that can change the wettability.

For example, when the photocatalyst in the photocatalyst-containing layer is titanium oxide, the light contains ultraviolet light. Examples of the light source containing such ultraviolet light include mercury lamps, metal halide lamps, xenon lamps, and the like. Excimer lamps and the like can be mentioned. Further, the photocatalyst containing layer may be exposed by applying a photocatalytic reaction start energy to the photocatalyst containing layer and applying a reaction rate increasing energy to a region where the photocatalytic reaction start energy is added. The photocatalytic reaction initiation energy in this case is not particularly limited as long as it is an energy capable of initiating the photocatalytic reaction, but is preferably light including ultraviolet light that initiates the catalytic reaction of titanium dioxide. . Specifically, a range of 400 nm or less, preferably 380 n
Light containing ultraviolet light in the range of m or less is preferred. Also,
It is preferable to use thermal energy as the energy for increasing the reaction rate. Examples of a method for applying such thermal energy include a method using an infrared laser and a method using a thermal head.

[0115]

EXAMPLE 3 g of isopropyl alcohol, fluoroalkylsilane (manufactured by Tochem Products Ltd .; MF-16)
0E (trade name), N- [3- (trimethoxysilyl) propyl] -N-ethyl perfluorooctanesulfonamide in isopropyl ether 50% by weight) 0.07
g, titanium oxide sol (manufactured by Ishihara Sangyo Co., Ltd .; STK-01)
(Trade name)) 3g, silica sol (Nippon Synthetic Rubber Co., Ltd.)
0.6 g of Glasca HPC7002 (trade name)) and alkylalkoxysilane (Nippon Synthetic Rubber Co., Ltd.)
0.2 g of HPC402H (trade name) manufactured by
Stirred at 00 ° C. for 20 minutes. 0.7 mm thick solution
Coated on a non-alkali glass substrate with a black matrix by a spin coating method,
After heating at 0 ° C, a photocatalyst-containing layer having a thickness of 0.15 µm was obtained.

The surface of the photocatalyst-containing layer was irradiated with an ultrahigh-pressure mercury lamp through a photomask to 70 mW / cm ² (35
UV irradiation at an illuminance of 6 nm for 3 minutes to change the wettability. As a result of measuring the contact angle of the unexposed portion and the exposed portion with water using a contact angle measuring device (CA-Z type, manufactured by Kyowa Interface Science Co., Ltd.), it was 70 degrees in the unexposed portion and 9 in the exposed portion.
Degree.

Next, using an ink jet device, an ink for forming a pixel portion having the following composition was dropped on the exposed portion.
Heated at 0 ° C. The composition of each ink is as follows.

(Ink for red) 5 g of pigment (CI Pigment Red 177) 20 g of solvent (propylene glycol monomethyl ether acetate) 5 g of polymerization initiator (Irgacure 369, manufactured by Ciba Specialty Chemicals) 5 g of UV curable resin (dipentaerythritol) Hexaacrylate, Nippon Kayaku Co., Ltd.) 70 g (blue ink) ・ Pigment (CI Pigment Blue 15 + CI Pigment Viole)
t 23) 5 g ・ Solvent (propylene glycol monomethyl ether acetate) 20 g ・ Polymerization initiator (Irgacure 369, manufactured by Ciba Specialty Chemicals) 5 g ・ UV curable resin (dipentaerythritol hexaacrylate, manufactured by Nippon Kayaku) 70 g (for green) Ink) ・ Pigment (CI Pigment Green 36) 5g ・ Solvent (propylene glycol monomethyl ether acetate) 20g ・ Polymerization initiator (Irgacure 369, manufactured by Ciba Specialty Chemicals) 5g ・ UV curable resin (dipentaerythritol hexaacrylate, Nippon Kayaku) 70 g)

Next, UV irradiation was performed to cure the pixel portion and to change the wettability of the photocatalyst-containing layer exposed between the pixel portions. Next, heat treatment was performed at 200 ° C. to accelerate the curing of the pixel portion, thereby completing the curing of the pixel portion. The critical surface tension of the pixel portion and the critical surface tension of the photocatalyst-containing layer between the pixel portions (after exposure) are shown below.

Pixel portion (red) 36 mN / m Pixel portion (blue) 37 mN / m Pixel portion (green) 37 mN / m Photocatalyst containing layer between pixel portions (after exposure) 69 mN / m

Next, a coating material for forming a coating portion having the following composition was applied to the photocatalyst-containing layer in the gap between the pixel portions and the photocatalyst-containing layer outside the display area using an ink jet device.

(Coating composition for coating part formation) 100 g of UV curing resin (beam set 267 (acrylic resin), manufactured by Arakawa Chemical Industries, Ltd.) 50 g of curing initiator (Irgacure 184, manufactured by Ciba Specialty Chemicals) After UV irradiation, a heat treatment was performed at 200 ° C. to form a coating portion.

The color liquid crystal display device using the obtained color filters had good display quality.

[0124]

According to the color filter of the present invention, since the covering portion is formed in the gap between the pixel portions, the photocatalyst-containing layer is not exposed at this portion. When a color liquid crystal display device is manufactured by the method described above, there is no possibility that the liquid crystal material in the liquid crystal layer and the photocatalyst-containing layer are in direct contact with each other. A good color liquid crystal display device can be provided. Furthermore, since the coating portion as described above is formed, a liquid crystal layer contaminant that causes a problem with the liquid crystal material in the liquid crystal layer when it elutes into the liquid crystal layer in the photocatalyst containing layer is mixed. In addition, such liquid crystal layer contaminants do not enter the liquid crystal layer, and there is no possibility that the liquid crystal material adversely affects display performance. In addition, since the covering portion is formed in the gap between the pixel portions, unevenness in this portion is reduced, and for example, when forming a relatively thin layer such as a transparent electrode layer or an alignment film, the unevenness is reduced. This has the effect of reducing the number of problems caused by this.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an example of a color filter of the present invention.

FIG. 2 is a process chart illustrating an example of a method for manufacturing a color filter of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Transparent substrate 2 ... Photocatalyst containing layer 3 ... Pixel part 4 ... Light shielding part 5 ... Cover part 11 ... Coating part forming paint

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2C056 EA24 FB01 2H025 AA00 AB13 AC01 BC14 BC43 CC12 DA03 DA36 DA40 EA01 EA03 FA03 FA39 2H048 BA02 BA11 BA16 BA17 BA29 BA64 BB02 BB14 BB28 BB44 2H091 FA02Y FA34 LA23 FB14

Claims (16)

[Claims] 1. A transparent substrate, and a photocatalyst-containing layer provided on the transparent substrate, the layer containing at least a photocatalyst and a binder, and having a wettability changed so that a contact angle with a liquid is reduced by exposure. In a color filter having at least a pixel portion provided with a predetermined pattern of a plurality of colors by an inkjet method on the photocatalyst containing layer and having a predetermined gap, a coating portion is formed in the gap between the pixel portions. A color filter characterized by being performed. 2. The color filter according to claim 1, wherein said coating portion is formed on a photocatalyst containing layer provided outside a display area formed by said pixel portion. 3. The color filter according to claim 1, wherein a height of the covering portion is equal to a height of the pixel portion. 4. A transparent substrate, and a photocatalyst-containing layer provided on the transparent substrate, the layer containing at least a photocatalyst and a binder and having a wettability changed so that a contact angle with a liquid is reduced by exposure. In a color filter having at least a pixel portion provided with a predetermined pattern of a plurality of colors by an inkjet method on the photocatalyst containing layer,
A color filter, wherein the covering portion is formed on a photocatalyst-containing layer provided outside a display region formed by the pixel portion. 5. The color filter according to claim 1, wherein the covering portion is formed of a material that does not adversely affect a liquid crystal material. 6. The coating section according to claim 1, wherein the coating section is formed using a paint having a surface tension greater than a critical surface tension of the pixel section. The color filter according to 1. 7. The light-shielding portion is formed on the transparent substrate, and the photocatalyst-containing layer is formed on the transparent substrate on which the light-shielding portion is formed. The color filter according to claim 6. 8. The method according to claim 1, wherein the photocatalyst is titanium oxide (Ti).
O ₂ ), zinc oxide (ZnO), tin oxide (SnO ₂ ), strontium titanate (SrTiO ₃ ), tungsten oxide (WO ₃ ), bismuth oxide (Bi ₂ O ₃ ), and iron oxide (Fe ₂ O ₃ ) The color filter according to claim 1, wherein the color filter is at least one substance selected from the group consisting of: 9. The color filter according to claim 8, wherein said photocatalyst is titanium oxide (TiO ₂ ). 10. The method according to claim 1, wherein the binder is Y _n SiX _(4-n) (where Y represents an alkyl group, a fluoroalkyl group, a vinyl group, an amino group, a phenyl group or an epoxy group;
Represents an alkoxyl group or a halogen. n is an integer from 0 to 3. 10. An organopolysiloxane which is one or more hydrolytic condensates or co-hydrolytic condensates of the silicon compound represented by the formula (1). The color filter according to 1. 11. A step of forming, on a transparent substrate, a photocatalyst-containing layer that contains at least a photocatalyst and a binder and that changes the wettability so that the contact angle with a liquid is reduced by exposure to light. (2) Exposure of energy to a pixel portion forming portion, which is a portion for forming a pixel portion on the photocatalyst-containing layer provided on the transparent substrate, to form a pixel portion exposing portion. Forming a pixel portion having a predetermined pattern and a predetermined gap by coloring the portion into a plurality of colors by an ink-jet method; and (3) covering the gap between the pixel portions with a coating material for forming a covering portion. And a step of forming a portion. 12. The method according to claim 11, wherein the step of forming the coating portion using the coating material for the coating portion is performed by a method of applying the coating material for the coating portion by a nozzle discharge method.
A method for producing the color filter according to the above. 13. The surface tension of the coating material for forming a coating portion,
13. The method according to claim 11, wherein the critical surface tension is larger than the critical surface tension of the pixel portion. 14. The method according to claim 1, wherein the step of forming the cover includes a step of forming a gap between the pixel units such that a critical surface tension of the photocatalyst-containing layer existing in the gap between the pixel units becomes larger than a critical surface tension of the pixel unit. 14. The method for producing a color filter according to claim 11, further comprising a step of exposing the color filter. 15. The method according to claim 11, further comprising, prior to the step of forming the photocatalyst-containing layer on a transparent substrate, a step of forming a light-shielding portion on the transparent substrate. A method for manufacturing a color filter according to claim. 16. A color liquid crystal display device comprising the color filter according to claim 1. Description: