JP2001242317A - 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 making the photocatalyst containing layer exposed between the pixel parts be removed.

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 exposing the photocatalyst-containing layer, and by forming a colored layer (pixel portion) thereon, it is inexpensive and high quality. A simple 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. Wherein the photocatalyst-containing layer exposed between the pixel portions is removed from the color filter.

In the color filter of the present invention, since the photocatalyst-containing layer exposed in the gap between the pixel portions is removed, the exposed area of the photocatalyst-containing layer in this portion is substantially equal to the thickness of the photocatalyst-containing layer. , Becomes extremely small. Therefore, when a color liquid crystal display device is manufactured using the color filter of the present invention, even if the liquid crystal layer and the photocatalyst-containing layer are in direct contact, there is no possibility that the liquid crystal material is adversely affected, and the color liquid crystal having good display quality is obtained. A display device can be provided. Furthermore, even if 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, the contact area with the liquid crystal material is extremely small. The amount of the liquid crystal layer contaminants eluted into the liquid crystal layer is extremely small, and there is no possibility that the display performance of the liquid crystal layer will be adversely affected.

According to the first aspect of the present invention, as described in the second aspect, the removal of the photocatalyst containing layer exposed between the pixel portions is performed by removing the photocatalyst containing layer exposed between the pixel portions. It is preferable that a developer is adhered and the photocatalyst containing layer is dissolved and removed by the developer. If the photocatalyst-containing layer exposed between the pixel portions is removed in this manner, the photocatalyst-containing layer can be removed by a simple process, which is advantageous in terms of cost.

According to the first or second aspect of the present invention, as described in the third aspect, a light-shielding portion is formed on the transparent substrate, and the transparent substrate on which the light-shielding portion is formed is provided. It may be a color filter on which the photocatalyst containing layer 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.

Any one of claims 1 to 3
In the color filter described in claim 1,
Item 4. As described in Item 4, 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
The substance is preferably a compound of the formula:
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 fifth aspects, as described in the sixth aspect, the binder includes 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 or a halogen. N is an integer of 0 to 3) ) Is preferably an organopolysiloxane which is one or more hydrolytic condensates or co-hydrolytic condensates of a silicon compound represented by the 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 7, (1) at least containing a photocatalyst and a binder,
Forming a photocatalyst-containing layer on a transparent substrate, the photocatalyst-containing layer being a layer whose wettability changes so that the contact angle with a liquid is reduced by exposure; and (2) a photocatalyst-containing layer provided on the transparent substrate. A pixel portion forming portion, which is a portion for forming a pixel portion on the layer, is irradiated with energy in a pattern to form a pixel portion exposing portion, and the pixel portion exposing portion is colored in a plurality of colors by an ink jet method to a predetermined color. A pixel portion forming step of forming a pixel portion having a predetermined gap with the pattern of (3), and (3) a developer capable of dissolving the photocatalyst containing layer on the photocatalyst containing layer exposed in the gap between the pixel portions And (4) a step of dissolving the photocatalyst-containing layer with the developer and then washing the developer. To provide.

By removing the photocatalyst-containing layer exposed between the pixel portions by such a process, the exposed area of the photocatalyst-containing layer which may come into contact with the liquid crystal material can be easily made very small. It is possible. Therefore, a color filter capable of obtaining a high-quality color liquid crystal display device with simple steps can be manufactured.

In the method for manufacturing a color filter according to the present invention, the developer is a developer having a surface tension larger than a critical surface tension of the pixel portion. Is preferred. If the surface tension of the developing solution is larger than the critical surface tension of the pixel portion, the developing solution has a contact angle with the pixel portion larger than 0 degree. For this reason, when the developing solution is applied between the pixel portions, the developing solution can be easily applied only to the photocatalyst-containing layer exposed between the pixel portions without spreading to the surface of the pixel portions.

Further, in the invention described in claim 7 or claim 8, as described in claim 9,
Before the developing solution applying step, 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 exposed to the gap between the pixel portions becomes larger than the critical surface tension of the pixel portion. Is preferred. Since the gap between the pixel portions is a concave portion, it is possible to attach a developer regardless of wettability on the photocatalyst containing layer. However, if the exposure is performed so that the critical surface tension of the photocatalyst-containing layer is larger than the critical surface tension of the pixel portion, the wettability to the developer is better for the photocatalyst-containing layer than for the pixel portion. Therefore, when the developing solution is applied between the pixel portions, it becomes possible to apply the developing solution more accurately on the photocatalyst-containing layer exposed between the pixel portions.

In the invention described in any one of claims 7 to 9, as described in claim 10, before the step of forming the photocatalyst-containing layer on a transparent substrate, Alternatively, the method may include a step of forming a light shielding portion on a transparent substrate. This is because the function and effect of the color filter manufacturing method of the present invention are not limited by the presence or absence of the light shielding portion.

Further, in the invention according to any one of claims 7 to 10, claim 1
Preferably, the developer is an alkaline solution capable of decomposing siloxane bonds. As described in claim 12, the developer is an aqueous sodium hydroxide solution or a hydroxide solution. It is preferably a potassium aqueous solution. As the binder contained in the photocatalyst-containing layer, a binder having a binding energy that is not easily cut by the action of the photocatalyst is preferable, and therefore a polymer having a siloxane bond is suitably used. Therefore, as the developer, an alkaline aqueous solution capable of decomposing such a siloxane bond is preferable, and in consideration of cost and the like, it is preferable to use sodium hydroxide or potassium hydroxide.

In the invention described in any one of the seventh to twelfth aspects, as described in the thirteenth aspect, the developing solution application step is performed using a nozzle discharge method. Is preferred. Inkjet,
By using a nozzle discharge method such as a dispenser,
The developer can be applied only to the concave portions in the gaps between the pixel portions where the photocatalyst containing layer is exposed. Therefore, the developer can be attached with higher accuracy than in the case of application by a dip coating method or the like.

According to a fourth 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 sixth 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.

[0022]

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 with a predetermined pattern of a plurality of colors by an inkjet method on the photocatalyst containing layer, and having a predetermined gap, wherein the photocatalyst containing portion exposed between the pixel portions is provided. Characteristic where the layer has been removed.

The present invention has the following effects because the photocatalyst-containing layer exposed in the gap between the pixel portions is removed as described above. That is, in a color liquid crystal display device, generally, a color filter and a counter electrode substrate facing the color filter are arranged at a predetermined interval, and a liquid crystal material is sealed between the color filter and the counter electrode substrate to form a liquid crystal layer. Is formed. 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 removing the photocatalyst containing layer exposed between the pixel portions, the contact area between the liquid crystal material and the photocatalyst containing layer becomes only the thickness of the photocatalyst containing layer. Here, the thickness of the photocatalyst-containing layer is generally in the range of 0.1 μm to 0.2 μm, whereas the width of the photocatalyst-containing layer exposed between the pixel portions depends on the type of the color filter. Is about 10 μm. Therefore, by removing the photocatalyst containing layer exposed between the pixel portions, the contact area between the photocatalyst containing layer and the liquid crystal material can be reduced to about 1/100. Therefore, it is possible to reduce the possibility that a problem such as deterioration in display quality of the liquid crystal layer occurs as described above.

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. However, there is a possibility that the light may pass through the thin film as described above 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. At this time, since the exposed area between the pixel portions of the photocatalyst-containing layer is removed, the contact area with the liquid crystal material can be significantly reduced, and therefore, the liquid crystal contaminants in the photocatalyst-containing layer enter the liquid crystal layer. Can be practically prevented, and problems such as deterioration of display quality of the liquid crystal layer can be prevented.

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 on a portion located above and between the pixel portions 3. The pixel portion 3 is formed on the photocatalyst-containing layer 2 in a predetermined pattern with a predetermined gap, and the photocatalyst-containing layer 2 exposed on the surface in the gap is removed. The removing unit 5 is provided. Hereinafter, each of these components will be individually described.

(Photocatalyst-containing layer removing portion) As described above,
The feature of the present invention is that the photocatalyst containing layer 2 exposed in the gap between the pixel portions 3 is removed as shown in FIG. The photocatalyst-containing layer removing portion in the present invention is formed by removing a portion of the photocatalyst-containing layer that is present in the gap between the pixel portions and is not covered by the pixel portion, and the removed portion is as shown in FIG. If the photocatalyst-containing layer 2 on the transparent substrate is not formed, the photocatalyst-containing layer 2 on the light-shielding portion 4 is removed. You.

The width of the photocatalyst-containing layer removed portion is the same as the width of the gap in the pixel portion. In the case where the light shielding portion 4 is formed on a transparent substrate as shown in FIG. 1, since the pixel portion 3 is usually formed so as to overlap a part of the light shielding portion 4, the photocatalyst containing layer removing portion 5 is formed. Is often formed to be smaller than the width of the light shielding portion 4, but the present invention is not limited to this.

The shape of the photocatalyst-containing layer-removed portion will be specifically described. The width of the photocatalyst-containing layer is the same as the width of the gap between the pixel portions as described above, and generally depends on the type of the color filter. It is in the range of 1 to 100 μm. The thickness of the photocatalyst-containing layer removed portion is the same as the thickness of the photocatalyst-containing layer, and varies depending on the color filter used, but is generally in the range of 0.01 to 0.5 μm.

The method for forming such a photocatalyst-containing layer removed portion is not particularly limited as long as the photocatalyst-containing layer exposed between the pixel portions can be removed. It is preferable that a developer that can be used is attached to the photocatalyst-containing layer exposed between the pixel portions, and the photocatalyst-containing layer is formed by dissolving the photocatalyst-containing layer with the developer. Since the type of the developer and the method of forming the photocatalyst-containing layer removed portion by the developer are the same as those described in detail in the method for manufacturing a color filter described below,
The description here is omitted.

(Transparent Substrate) As shown also in FIG. 1, the color filter of the present invention has at least a photocatalyst-containing layer 2 having a photocatalyst-containing layer removed portion 5 formed on a transparent substrate 1 and a pixel portion 3. However, such a transparent substrate is not particularly limited 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, as shown in FIG. 1, a photocatalyst-containing layer 2 provided with a photocatalyst-containing layer removing portion 5 is formed on the transparent substrate 1. Such a photocatalyst containing layer used in the present invention,
The layer has at least a photocatalyst and a binder, and has a wettability that changes by exposure so that a contact angle with a liquid is reduced. Although not particularly limited, the photocatalyst-containing layer in the present invention is a layer 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 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, and preferably a contact angle of not less than 10 degrees with a liquid having a surface tension of 30 mN / m in a portion not exposed. 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.

In the photocatalyst-containing layer, the contact angle with the liquid decreases when exposed to light, 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 developer is applied, the lower the contact angle with the liquid in the exposed portion, the easier the developer is attached.

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, by selecting the type of the binder, the photocatalyst before exposure can be obtained. 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.

Further, 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 and 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 or the like only on a single pixel, and a low-cost and high-quality color filter can be obtained. In addition, since the photocatalyst-containing layer can be easily exposed to the gap between the pixel portions by exposing when forming the photocatalyst-containing layer removed portion, the photocatalyst-containing layer can be made to be the ink-philic region because it can be made into an ink-philic region by exposure. Thus, the developer can be accurately adhered thereto.

As described above, the fluorine content in the photocatalyst containing layer containing fluorine is determined by the amount of fluorine in the ink-philic region formed by exposure and having a low fluorine content. 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 the content within such a range, a great difference can be caused in wettability 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 the like only in an ink-philic region having a reduced fluorine content, and to obtain a color filter with high accuracy. Because it can be. In addition, this reduction rate is based on weight.

For the measurement of the fluorine content in the photocatalyst-containing layer, various commonly used methods can be used. For example, X-ray photoelectron spectroscopy (X-ray Phot spectroscopy)
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, an anatase-type titania sol of peptized hydrochloric acid (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 of the surface of the photocatalyst-containing layer. A color filter obtained by forming a pattern of an ink-philic region in an ink-repellent region and forming a pixel portion or 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. When analyzed by spectroscopy and quantified, when the titanium (Ti) element is taken as 100, the fluorine (F) element has a ratio of 500 or more, preferably 800 or more, particularly preferably 1200 or more. ) The element is preferably contained on the surface of the photocatalyst containing layer.

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 50 or less when the titanium (Ti) element is 100, and 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 in 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, in particular, 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 fluorosiloxane-containing polysiloxane 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 compounds having a skeleton represented by the following general formula.

[0058]

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.

In the photocatalyst-containing layer, in addition to the above-mentioned surfactants, polyvinyl alcohol, unsaturated polyester, acrylic resin, polyethylene, diallyl phthalate, ethylene propylene diene monomer, epoxy resin, phenol resin, polyurethane, melamine resin , Polycarbonate, polyvinyl chloride, polyamide, polyimide, styrene butadiene rubber, chloroprene rubber, polypropylene, polybutylene, polystyrene, polyvinyl acetate, polyester, polybutadiene, polybenzimidazole, polyacrylonitrile, oligomers such as 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. Here, the predetermined interval is the same as the width of the photocatalyst-containing layer-removed portion, which is a characteristic portion of the color filter of the present invention described above.

The ink-jet type ink for forming such a pixel portion is roughly classified into water-based and oil-based 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, although the ink of the ordinary ink jet system cannot contain a large amount of binder resin due to its low suitable viscosity, 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 a 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-propadione-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. The light-shielding portion in such a case is not limited to this. Usually, a metal thin film of chromium or the like having a thickness of about 1000 to 2000 mm is formed by a sputtering method, a vacuum evaporation method, or the like, and the thin film is patterned. It is formed. As this patterning method, an ordinary patterning method such as sputtering can be used.

In the case of forming a light shielding portion in the present invention,
It is preferable that the width of the light shielding portion is formed wider than the width of the photocatalyst containing layer removed portion. This is to prevent problems such as color omission when a color liquid crystal display device is formed.

(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.

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 a photocatalyst-containing layer to be formed; and (2) exposing the pixel portion to a pixel portion forming portion, which is a portion where a pixel portion on the photocatalyst-containing layer provided on the transparent substrate is formed, by applying energy in a pattern. To form
A pixel portion forming step of 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) exposing the pixel portion to the gap between the pixel portions. A developer application step of applying a developer capable of dissolving the photocatalyst-containing layer on the photocatalyst-containing layer; and (4) washing the developer after dissolving the photocatalyst-containing layer with the developer. And at least steps. Hereinafter, each of the above steps will be described.

FIG. 2 is a view 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 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, the 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 portion forming ink is jetted into the pixel portion exposing portion 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 it 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 this ink solidification step, the type of 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 section 8 is uniformly spread, when the ink is solidified in this way, it is possible to form the pixel portion 3 without color loss or color unevenness. .

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 developer-adhering exposure portion 9 which is an ink-philic region (FIG. 2). (D)).

Here, it is preferable that the developing solution adhering exposure section 9 is exposed such that its critical surface tension is larger than the critical surface tension of the pixel section. That is, if the exposure is performed so that the critical surface tension of the developing solution attaching exposure portion 9 which is a photocatalyst containing layer becomes larger than the critical surface tension on the pixel portion 3, the wettability to the developing solution described later is reduced. When the developer is applied to the gap between the pixel portions 3, it is more accurately applied on the photocatalyst-containing layer exposed between the pixel portions 3 because the exposure portion 9 for applying the developer is better than that of This is because it becomes possible.

Then, in the developing solution attaching exposure section 9,
The developing solution 11 is applied to the developing solution applying exposure section 9 in the gap between the pixel sections 3 using the ink jet device 10. At this time, since the inside of the developing solution adhering exposure unit 9 becomes an ink-philic region having a small contact angle with the liquid due to the exposure as described above, the developing solution 11
It spreads evenly in the developing solution attaching exposure section 9.

The method of applying the developing solution 11 is not limited to the above-described ink-jet method, but may be applied by utilizing a difference in wettability by various methods such as commonly used dip coating. Is also good. However, for example, it is possible to selectively apply only the gaps between the pixel portions, and thereby the photocatalyst-containing layer can be applied without providing a difference in wettability by exposing the photocatalyst-containing layer. It is preferable to use a method based on nozzle discharge from the viewpoint that the possibility of performing the process is low. Examples of such a nozzle ejection method include a micro syringe, a dispenser, an ink jet, a method in which a developer is ejected from a needle tip by an external stimulus such as an electric field, and a method in which a developer is oscillated by an external stimulus such as a piezo element. Can be used, and a method in which a developer attached to the needle tip is attached to the surface of the photocatalyst-containing layer can be used. Among them, ink jet methods can be mass-produced, which is advantageous in terms of cost. Is preferred. The ink jet device used in this case is not particularly limited, but a method in which charged ink is continuously ejected and controlled by a magnetic field, a method in which ink is ejected intermittently using a piezoelectric element, and a method in which ink is heated As in the case of the above-described ink for forming a pixel portion, an inkjet apparatus using various methods, such as a method of intermittently ejecting by utilizing the foaming, can be used.

It is preferable that the surface tension of the developing solution 11 used is larger than the critical surface tension of the pixel portion 3. This is because the surface tension of the developing solution 11 is lower than the pixel portion 3.
If the critical surface tension is larger than the critical surface tension, the developer 11 has a contact angle larger than 0 degree with respect to the pixel portion 3. For this reason, when the developing solution 11 is applied to the developing solution applying exposure portion 9 between the pixel portions 3, the backlight 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 passing part. Thereby, without giving an adverse effect such as dissolution of the pixel portion 3,
This is because the developer 11 can be easily attached only to the photocatalyst-containing layer exposed between the pixel portions 3.

In the present invention, when the photocatalyst-containing layer is formed of a binder having a siloxane bond,
The developer is preferably an alkaline solution capable of decomposing such siloxane bonds. Examples of such an alkaline solution include an aqueous solution of an organic alkali and an inorganic alkali.

Preferred examples of the alkaline solution include an aqueous solution of sodium hydroxide and an aqueous solution of potassium hydroxide. The preferred pH is pH 7-14, particularly preferably pH 10-14, and the most preferred pH is pH 12-14. is there.

Finally, after the photocatalyst-containing layer 2 at the portion where the developing solution has adhered is dissolved and removed with the developing solution 11, a washing step of washing the variable wettability layer is performed. Thereby, only the portion of the photocatalyst containing layer 2 exposed between the pixel portions 3 is removed to obtain a color filter in which the photocatalyst containing layer removal portion 5 is formed (FIG. 2E). The cleaning step in this case is not particularly limited, and can be performed in the same manner as a cleaning step generally performed in a photolithography step or the like.

In the example shown in FIG. 2, the example in which the light-shielding portion 4 is formed is shown. However, the method for manufacturing the color filter of the present invention is not limited to this, and there is no step of forming the light-shielding portion 4. It may be a manufacturing method, that is, a method of manufacturing a color filter having no light shielding portion.

In the example shown in FIG. 2, after the pixel portion is formed, exposure is performed by forming an exposure portion 9 for applying a developing solution, and a developing solution 11 is applied and dissolved therein to remove the photocatalyst-containing layer. Although the portion 5 is formed, the present invention is not limited to this, and may be a manufacturing method without performing exposure. That is, when the photocatalyst-containing layer exposed between the pixel portions is removed, since a concave portion is formed between the pixel portions (see, for example, FIG. 2C), a developer is attached to the concave portion by an inkjet method or the like. Accordingly, only the photocatalyst-containing layer at this portion can be removed to form a photocatalyst-containing layer removed portion. In this case, it is not necessary to expose the photocatalyst-containing layer. However, considering that the difference in wettability makes it easier and more accurate to apply the developer, the critical surface tension of the photocatalyst-containing layer is reduced in the pixel portion as in the example shown in FIG. It is preferable that the exposure is performed so as to be larger than the critical surface tension.

[0097] 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 thus obtained has the advantages 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. As a light source of such ultraviolet light, for example, a mercury lamp, a metal halide lamp, a xenon lamp, 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.

[0101]

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 by spin coating, heated at 150 ° C. for 20 minutes,
A photocatalyst-containing layer having a thickness of μm was obtained.

The surface of the photocatalyst-containing layer was exposed to a light of 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, the following ink for forming a pixel portion was dropped on the exposed portion using an ink jet device, and then heated at 80 ° C.・ Ink for red color: Fuji Film Ohlin Co., Ltd., CR-2
000 ・ Blue ink: CB-2, manufactured by Fuji Film Ohrin Co., Ltd.
000 ・ Green ink: CG-2, manufactured by Fuji Film Ohrin Co., Ltd.
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.

Next, the pH was measured using an ink jet device.
13. A potassium hydroxide aqueous solution having a contact angle of 55 degrees with the unexposed portion of the photocatalyst-containing layer was discharged to the exposed portion. After 2 minutes, the substrate was rinsed with pure water to remove the photocatalyst-containing layer present in the gap between the pixel portions.

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

[0106]

According to the color filter of the present invention, since the photocatalyst containing layer exposed in the gap between the pixel portions is removed, the exposed area of the photocatalyst containing layer in this portion is substantially equal to the thickness of the photocatalyst containing layer. Therefore, it becomes extremely small. Therefore, when a color liquid crystal display device is manufactured using the color filter of the present invention, even if the liquid crystal layer and the photocatalyst-containing layer are in direct contact, there is no possibility that the liquid crystal material is adversely affected, and the color liquid crystal having good display quality is obtained. A display device can be provided. Furthermore, even if a liquid crystal layer contaminant that causes a problem with the liquid crystal material in the liquid crystal layer when eluted into the liquid crystal layer in the photocatalyst containing layer is mixed,
Since the contact area with the liquid crystal material is extremely small, the amount of the liquid crystal layer contaminants eluted into the liquid crystal layer is extremely small, and there is an effect that the display performance of the liquid crystal layer is not adversely affected.

[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 ... Photocatalyst containing layer removal part 11 ... Developer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C056 FB01 FB08 2H048 BA02 BA56 BA57 BA60 BB02 BB14 BB24 BB42 2H091 FA02Y FA34Y FB02 FC02 LA15 LA30 5C094 AA08 AA31 AA43 AA44 AA48 AA54 BA43 FB01 FB01 FB01 FB02 GB10

Claims (14)

[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 photocatalyst-containing layer exposed between the pixel portions is provided. A color filter that has been removed. 2. The photocatalyst-containing layer exposed between the pixel portions is removed by depositing a developer on the photocatalyst-containing layer exposed between the pixel portions, and dissolving and removing the photocatalyst-containing layer with the developer. The color filter according to claim 1, wherein the color filter is a color filter. 3. A 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 1. 4. The photocatalyst comprises 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 any one of claims 1 to 3, wherein the color filter is at least one substance selected from the group consisting of: 5. The color filter according to claim 4, wherein said photocatalyst is titanium oxide (TiO ₂ ). 6. The method according to claim 1, wherein the binder is Y _n SiX _(4-n) (where Y is an alkyl group, a fluoroalkyl group, a vinyl group,
X represents an amino group, a phenyl group or an epoxy group, and X represents an alkoxyl group or a halogen. n is an integer from 0 to 3. 6. An organopolysiloxane which is one or more hydrolytic condensates or co-hydrolytic condensates of a silicon compound represented by the formula (1). The color filter according to 1. 7. A photocatalyst-containing layer comprising at least a photocatalyst and a binder, wherein the photocatalyst-containing layer is a layer whose wettability changes so that the contact angle with a liquid is reduced by exposure on a transparent substrate. Forming a pixel portion on a photocatalyst-containing layer provided on the transparent substrate; and A pixel portion forming step of 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) a photocatalyst exposed to the gap between the pixel portions A developer application step of applying a developer capable of dissolving the photocatalyst containing layer on the content layer, and (4) a washing step of washing the developer after dissolving the photocatalyst containing layer with the developer. When A method for producing a color filter, comprising at least: 8. The method according to claim 7, wherein the developer has a surface tension greater than a critical surface tension of the pixel portion. 9. The method according to claim 1, wherein the step of exposing the gap between the pixel units is performed such that a critical surface tension of the photocatalyst-containing layer exposed in the gaps between the pixel units is larger than a critical surface tension of the pixel unit. 9. The method for manufacturing a color filter according to claim 7, further comprising the step of: 10. The method according to claim 7, further comprising, before 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. 11. The method according to claim 7, wherein the developing solution is an alkaline solution capable of decomposing siloxane bonds. . 12. The method according to claim 11, wherein the developer is an aqueous solution of sodium hydroxide or an aqueous solution of potassium hydroxide. 13. The method according to claim 7, wherein the developing solution applying step is performed using a nozzle discharge method. 14. A color liquid crystal display device comprising the color filter according to claim 1. Description: