JPH05142416A - Color filter - Google Patents

Abstract

PURPOSE:To obtain the color filter provided with colored layers having good ink penetratability and exhaustion rate by specifying the compds. constituting blank materials for transparent film bodies which constitute the base material layers of the colored layers. CONSTITUTION:The base polymers of the transparent film bodies constituting the base materials of the colored layers to be formed on a substrate consisting of glass, etc., namely the base polymers of transparent base materials to be colored are constituted mainly of the compds. contg. the constitutional unit expressed by formula. As a result, the colored layers which have the excellent ink penetratability and exhaustion rate and have extremely high heat resistance are surely obtd. The compds. contg. the structure expressed by the formula exhibit a cationic property in an acidic liquid and are the good exhaustion point in the case of use of the acidic dyes. In addition, the compds. have three pieces of the exhaustion points within one constitutional unit and, therefore, the efficient dyeing is possible by incorporating, a small amt. of the compds. into the colored layers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter used in a color liquid crystal display device or the like.

[0002]

2. Description of the Related Art As a means for colorizing a liquid crystal display element, a method of attaching a color filter to the surface of the liquid crystal element is generally used. In that case, as a color filter, a colored layer having a thickness of 1 to 2 μm is usually formed on the entire surface of the transparent substrate.
A fine pattern having a size of 70 to 150 μm square is used. Conventionally, as a method of forming a color filter, methods called a pigment or dye dispersion method and a dyeing method have been widely used. That is, in the former method, a mono-colored pigment or dye dispersed in a photo-curable polymer or monomer is coated on the entire surface of a transparent substrate, and light is irradiated according to a predetermined pattern, and then unnecessary portions are dissolved and washed. This is a method of forming a color filter by repeating the steps of three steps of red, blue and green. In the latter case, a transparent photo-curable polymer or monomer is applied on the entire surface of a transparent substrate, and after photo-patterning in the same manner as the former, the step of immersing in a dye ink of a single color to dye it is red, This is a method of forming a color filter by repeating three colors of blue and green.

In these methods, it is necessary to pattern the colored layer. Usually, the colored layer is formed of a polymer or monomer having photosensitivity, and is patterned by using light. However, when the colored layer does not have the ability, another photosensitive layer is formed on the colored layer. It is necessary to overlap the above, and after photosensitizing the photosensitive layer, use it as a mask to etch the colored layer. For the above reasons, conventionally, a transparent photosensitive resin has been mainly used as a colored layer of a color filter. Dyeing method In many cases, gelatin or PVA with photosensitivity has been used for the colored layer of the color filter. However, all of these chromosomes lack heat resistance. That is, when heated at 180 to 200 ° C. for about 1 hour, the colorless and transparent color changes to yellow. This is not preferable considering the process of incorporating the color filter into the liquid crystal element.

However, in the color filter forming methods other than the above dispersion method and dyeing method, the colored layer is not necessarily patterned.
There are also methods that do not need to be converted. For example, in the case of coloring by ejecting ink by an inkjet method, the position can be controlled by the inkjet head, and it is not necessary to pattern the colored layer. The same applies to a so-called printing method in which ink is supplied by a transfer method. By utilizing this feature, the selection range of the material used for the colored layer is greatly expanded. As a result, there is room for improvement in terms of heat resistance, which has hitherto been said to be a drawback of dyeing color filters.

On the other hand, in the case of the above-mentioned ink jet system or printing system, it is not necessary for the polymer forming the colored layer to have photosensitivity, but instead, the conventional dyeing method or dispersion method is much emphasized. Properties such as ink penetration, dyeing speed, and room temperature dyeing become very important. The materials that have been conventionally used for the coloring layer of the dyeing color filter are insufficient in the above-mentioned properties for the inkjet system or the printing system, and a good color filter cannot be obtained.

More specifically, in the case of the ordinary dyeing method, the substrate is dipped in a dyeing solution warmed to about 60 to 100 ° C. for about 3 to 5 minutes for dyeing. Therefore, the ink permeability and the dyeing speed of the colored layer do not need to be so high. Rather, the colored layer is required to have mechanical strength so as not to be damaged under this condition. For the above reasons, a crosslinked gelatin film has been conventionally used for the coloring layer of the dyeing method color filter.

On the other hand, in the case of the ink jet system, the ink droplets ejected from the nozzle adhere to the colored layer. The ink then penetrates into the colored layer in competition with the evaporation of the solvent. Therefore, it is necessary that the ink solvent sufficiently penetrates into the colored layer and dyes before being evaporated. In fact, when dyeing using the inkjet method and printing method,
The cross-linked gelatin film is insufficient in terms of ink permeability and dyeing speed, and a good color filter cannot be obtained. Furthermore, in order to realize a dyeing environment similar to that of the dip dyeing method using an inkjet method, heating the ink in the head, heating the entire substrate including the coloring layer, and preventing the evaporation of the ink due to the temperature rise are performed. Humidification of the whole has to be considered, which greatly complicates the device. The same applies to the printing method using the dye ink.

[0008]

SUMMARY OF THE INVENTION The present invention was devised in view of the above-mentioned drawbacks of the prior art. The object of the present invention is to provide good ink permeability and good ink penetration even when coloring by an inkjet method or a printing method. Another object of the present invention is to provide a color filter having a colored layer which exhibits a dyeing speed and has higher heat resistance than conventional color filters.

[0009]

The object of the present invention is as follows.
In a color filter provided with a substrate and a colored layer formed on the substrate, the transparent film body constituting the base material layer of the colored layer has the following formula (1).

[0010]

[Chemical 2]

This is achieved by a color filter characterized by being mainly composed of a compound containing a structural unit represented by:

That is, according to the present invention, the substrate polymer of the transparent film body constituting the substrate layer of the colored layer formed on the substrate such as glass, that is, the substrate polymer of the transparent substrate to be colored is represented by the following formula (1).

[0013]

[Chemical 3]

It is important that the compound is mainly composed of a compound containing a structural unit represented by the formula (1), whereby a colored layer having good ink permeability and dyeing speed and having extremely high heat resistance can be reliably obtained. be able to.

The compound containing the structure represented by the formula (1) exhibits a cationic property in an acidic liquid, which is a good dyeing point when an acidic dye is used. Moreover, since one structural unit has three dyeing points, it can be dyed efficiently by containing a small amount of it. As the dyeing point, a compound having only the structural unit represented by the formula (1) may be used, or a substance having another cationic structural unit such as amine, amide, quaternary ammonium salt, and pyrrolidone ring. You may use it at the same time.

The N-terminal of the structural unit represented by the formula (1) includes --NH ₂ , --NH (ROH), and --N (RO.
H) ₂ , -NH (ROR '), -N (ROR')
₂ (R, R '; chain or cyclic alkyl group) etc. Alco-
It is possible to use those to which a ruthel or ether is added.

From the viewpoint of the ink permeability of the colored layer, the alcohol adduct has a very high permeability of the water-soluble ink because it contains many OH groups which are hydrophilic groups. The hydrophilicity can be controlled by the ratio of the etherification degree of the alcohol moiety. Moreover, the alcohol adduct and the ether compound can be crosslinked by a condensation reaction with other OH groups by heating. The ink permeability of the colored layer and the hardness of the layer can be controlled by the above-mentioned ratios of alcoholization degree and etherification degree, but it is possible to mix with other hydrophilic and hydrophobic polymers or monomers. It can be adjusted over a wider range by using it. As specific examples of the polymer mixed to increase the hydrophilicity, polyvinyl alcohol, polyhydroxyethyl methacrylate, a polymer having an OH group such as polyvinyl alcohol and polyvinylpyrrolidone are suitable. A polymer containing an amine salt or an ammonium salt can also be used. Further, as a monomer for increasing the hydrophilicity, ethylene glycol, polyvalent alcohol such as glycerin, or an ether compound thereof, a monomer having an OH group,
Suitable are monosaccharides or derivatives thereof such as diose, triose, tetroses, pentose and hexose, and polysaccharides such as starch, glycogen and cellulose and derivatives thereof. In order to increase the hydrophobicity, it is desirable to mix and use polymers such as polymethyl acrylate and polymethyl methacrylate. Furthermore, the polymer and monomer components that increase hydrophilicity or hydrophobicity are not limited to the above, and can be appropriately selected according to individual dyeing conditions. The alcohol of the structural unit described in formula (1)
Since the silicone adduct itself has thermal crosslinking properties, cracking and film peeling may occur due to film shrinkage during crosslinking. It is more desirable to include 0.5 to 30% by weight of a polymer component, for example, polyhydroxyethylmethacrylate, to improve it.

On the other hand, the ink penetrability of the colored layer is greatly related to the swelling property of the colored layer. The equilibrium swelling degree (swelling ratio in the state where the swelling before and after the ink reaches the equilibrium), which is a major factor that determines the swelling property, is determined by the number of crosslinking points contained in the colored layer and the elastic modulus of the constituent polymer. .. Therefore, it is desirable that the colored layer having good ink permeability contains as many structural units as possible with a strong affinity for the ink solvent, a structural unit with a low elastic modulus is selected, and the number of crosslinking points is as small as possible. In this way, reducing the number of crosslinking points in the colored layer improves the ink permeability, but on the other hand, a small number of crosslinking points causes problems in solvent resistance and mechanical strength after forming a color filter. .. As a means for solving the above problems, at the time of dyeing, the colored layer is not crosslinked at all, or is dyed in a slightly crosslinked state,
After that, it is effective to use a step of completely crosslinking by applying heat.

The color filter according to the present invention can be produced, for example, as follows. First, a solution prepared by diluting a predetermined amount of the compound having the structural unit represented by the formula (1) with water, an organic solvent or the like is prepared and applied onto a glass substrate by spin coating or the like. Then, the coating film is 60 to 10
After drying in an oven at 0 ° C for 5 to 60 minutes, 120
A transparent film body having a predetermined film thickness is formed by thermal crosslinking at 150 ° C for 5 to 30 minutes. Subsequently, a predetermined coloring ink is supplied to predetermined portions on the obtained color filter substrate by an ink jet method or a printing method to color the three primary colors of red, blue and green. Next, the color filter on which a predetermined pixel pattern is drawn is washed with water and dried to obtain a high-quality color filter. Further, in the above method, the example in which the transparent film body was cross-linked before the drawing was described, but after the coating film is dried at 60 to 100 ° C. for 5 to 60 minutes, coloring is performed by an inkjet method or a printing method before heat crosslinking. It is also possible to perform crosslinking, and then heat at 120 to 180 ° C for 0.5 to 1 hour to crosslink. When this method is used, it is possible to obtain a high-quality color filter having improved ink penetration and dyeing property and higher transparency as compared with the former method.

When forming the colored film on the glass substrate, a coupling agent, for example, an aminosilane coupling agent, is applied to the glass substrate in an extremely thin thickness in advance in order to improve the adhesiveness with the glass substrate. It is very effective to leave.

As the colored ink, an aqueous solvent type ink containing an acid dye is suitable. In order to improve the dyeing speed and the dyeing strength, it is desirable to add a small amount of an acid such as acetic acid, formic acid and sulfuric acid or a salt such as ammonium acetate and ammonium sulfate to the ink. Further, in order to improve the penetrability of the ink into the colored layer and the wettability of the ink, it is more desirable to add a small amount of an ionic surfactant or a nonionic surfactant. As the ionic surfactant, for example, ammonium polyoxyethylene sulfonate, sodium polyoxyethylene sulfonate, sodium lauryl trimethyl ammonium chloride, sodium lauryl sulfate, sodium dodecylbenzene sulfonate, and the like can be used, but are not limited thereto. is not. Suitable nonionic surfactants include, but are not limited to, polyoxyethylene lauryl ether, polyoxyethylene nonylphenyl ether, sorbitan monolaurate tetraoleate polyoxyethylene sorbite, and the like. Not something to do.

[0022]

EXAMPLES The present invention will be described in more detail below with reference to examples.

Example 1 Partially butyletherified methylolated melamine ("Super-Beckamine" J820-6) on a washed glass plate.
0 (Dainippon Ink Co., Ltd.) (20% by weight)
Solution (80% by weight) diluted by spin coating.
After being dried at 80 ° C. for 10 minutes, it was thermally crosslinked in an oven at 140 ° C. for 0.5 hour to obtain a transparent film body having a film thickness of 2 μm. On the substrate, red, blue and green pixel patterns of color filters were drawn by using an inkjet printer. The ink is a dye for color filter PC-G10P (green), PC-R24P, manufactured by Nippon Kayaku Co., Ltd.
(Red) and PC-B5P (blue) were dissolved in distilled water, and acetic acid and a small amount of polyoxyethylene sulfonate ammonium as an ionic surfactant were added to each color ink. After drawing, the color filter was washed with water and dried in an oven at 80 ° C. for 20 minutes to obtain a good color filter having high transparency. 2 this color filter
After heating at 30 ° C. for 1 hour, no thermal discoloration was observed.

Example 2 Partially butyl etherified methylol melamine ("su-
Per-Beckamine "J820-60 (Dainippon Ink and Chemicals, Inc.)" was diluted with i-propanol, and polyhydroxyethyl methacrylate dissolved in i-propanol was used as a melamine resin in a weight ratio. By adding 20% by weight, a solution consisting of 20% by weight of melamine component, 4% by weight of polyhydroxyethyl methacrylate component and 76% by weight of solvent component was obtained, and the solution was spin-coated on a washed glass plate. After drying at 80 ° C for 10 minutes, 1
A transparent film having a film thickness of 1 μm was obtained by crosslinking in an oven at 40 ° C. for 0.5 hour. Thereafter, the dye ink was transferred onto the above substrate using a flatbed lithographic offset printing machine to obtain a good color filter having high transparency. This color
The filter was heated at 230 ° C. for 1 hour, but no discoloration was observed.

EXAMPLE 3 Methylolated melamine ("Sumiresin" M) diluted with water
3 (Sumitomo Chemical Co., Ltd.)), and 5% by weight of melamine resin of hydroxypropyl cellulose also dissolved in water, and an amine curing agent (ACX (Sumitomo Chemical Co., Ltd.)) of 5% by weight of melamine component. 20% by weight of melamine component, hydroxypropyl cellulose
1% by weight, curing agent 1% by weight, solvent component 78% by weight
A solution consisting of The above solution was spin-coated on a washed glass plate. After drying at 80 ° C for 10 minutes, 12
The melamine component was crosslinked by heating at 0 ° C. for 15 minutes to obtain a transparent film body having a film thickness of 1.5 μm. The following steps were performed in the same manner as in Example 1 to obtain a good color filter having high transparency. This color filter was heated at 230 ° C. for 1 hour, but no discoloration was observed.

Example 4 A solution similar to that used in Example 2 was spin-coated on a glass plate and then heated at 80 ° C. for 10 minutes to evaporate the solvent to obtain a transparent film having a thickness of 2 μm. .. Then, when the pixel pattern was subjected to inkjet drawing by the same method as in Example 1, quicker and better ink penetration and dyeing could be realized as compared with the result of Example 1. After drawing, it was heated at 140 ° C. for 1 hour to crosslink the melamine component. The above cross-linking treatment increased the mechanical strength and gloss of the filter surface. Then, it was washed with water and dried at 80 ° C. for 20 minutes to obtain a color filter. 2 the above color filter
After heating at 30 ° C for 1 hour, no discoloration was observed.

Example 5 A solution similar to that used in Example 3 was spin-coated on a glass substrate and then heated at 80 ° C. for 10 minutes to evaporate the solvent. When a color filter pattern was printed by transferring the dye ink on the above-mentioned substrate in the same manner as in Example 2, better ink penetration and coloring could be realized as compared with the result of Example 2. It was Then, the mixture was heated at 140 ° C. for 1 hour to completely crosslink the melamine component in the colored layer, washed with water and dried at 80 ° C. for 20 minutes, and as a result, a color filter having high transparency and heat resistance was obtained.

[0028]

Since the present invention has the above-mentioned constitution, it has a remarkably high ink permeability and a dyeing speed as compared with the coloring layer which has been conventionally used for the color filter of the dyeing method. The colored layer is particularly suitable when a dyeing color filter is manufactured by an inkjet method or a printing method, and by using it, it is much more uniform and clearer than a conventional one, and has high image quality and high heat resistance. It is possible to provide a color filter having

Claims (3)

[Claims] 1. In a color filter comprising a substrate and a colored layer formed on the substrate, a transparent film body constituting a base material layer of the colored layer is represented by the following formula (1): A color filter mainly comprising a compound containing a structural unit represented by: 2. The color filter according to claim 1, wherein the transparent film body is colored by an inkjet method or a printing method. 3. The color filter according to claim 1, wherein the transparent film body is colored and then crosslinked.