JPH07104118A - Color filter - Google Patents

Abstract

PURPOSE:To produce the color filter capable of continuous printing stably without secular change during printing by properly patterning the prescribed color of a specified ink on a substrate and printing. CONSTITUTION:In the color filter 10, a transparent electrode 13 is provided on the surface of the color filter layer 12 consisting of the color layer which is formed on the substrate 11 and combined properly from the plural colors of R (red layer), G (green layer) and B (blue layer). The color filter layer 12 formed on the substrate 11 is composed of a vehicle and the org. pigment dispersed in this vehicle, and this vehicle is composed of two kinds composition of thermosetting type melamine resin and epoxy resin. In this case, the thermosetting type melamine resin is the thermosetting resin obtained by the addition polymerization reaction of melamine and aldehydes, and the epoxy resin is the high polymer substance formed by the ring opening reaction of an epoxy group.

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 display device, and is particularly devised so that stable printing can be performed under steady conditions.

[0002]

2. Description of the Related Art For example, color display devices such as color liquid crystal display devices, color facsimiles, and color video cameras are equipped with color filters.
It is obtained by the dyeing method, dispersion method, electrodeposition method and printing method. Among them, the printing method is more widely used because it is superior to other methods in terms of low cost, large area, and mass productivity.

In the conventional manufacturing technique of a color filter by this printing method, a technique using a thermosetting melamine resin as one having improved heat resistance (Japanese Patent Application Laid-Open No. 63-12930).
No. 3), and a technique (see Japanese Patent Laid-Open No. 63-129302) in which a thermosetting melamine resin is mixed with an epoxy resin to improve the adhesion to a glass substrate or the like. .

[0004]

By the way, when a color filter is manufactured by the above printing method, the evaporation rate of the solvent mixed in the vehicle has a great influence on the printability. That is, when a large amount of color filters are continuously printed by a printing method, a part of the solvent evaporates, and the viscosity of the ink increases. As a result, there is a problem that continuous printing cannot be performed under steady conditions. is there.

Therefore, conventionally, an aliphatic alcohol having a boiling point of 120 ° C. to 260 ° C. has been used as a solvent for adjusting viscosity after vehicle preparation, but from the viewpoint of printing accuracy and workability, this solvent for adjusting viscosity is used. It is desirable to have a vehicle that does not use any fatty alcohols.

In view of the above problems, it is an object of the present invention to provide a color filter which can be continuously and stably printed without changing with time during printing of the color filter.

[0007]

Means for Solving the Problems The structure of a color filter according to the present invention which achieves the above objects, is a vehicle having a viscosity lower than a printability viscosity and a vehicle obtained by mixing only a vehicle having a viscosity higher than the printability viscosity. An ink comprising an organic pigment dispersed in the vehicle is printed on a substrate by appropriately patterning a predetermined color.

In the above structure, the vehicle is preliminarily reacted in advance.

In the above structure, the printability viscosity is 25P.
as ~ 250 Pa.s, and the viscosity of the low viscosity vehicle is 0.
5 Pa.s to 25 Pa.s, viscosity of high viscosity vehicle is 250
It is characterized in that it is Pa.s to 1000 Pa.s.

The contents of the present invention will be described below.

FIG. 1 shows an example of a color filter according to the present invention. As shown in the figure, the color filter 10 includes R (red layer), G (green layer), and B formed on the substrate 11.
The transparent electrode 13 is provided on the surface of the color filter layer 12 including a color layer in which a plurality of colors (blue layer) are appropriately combined.

The color filter layer 12 formed on the substrate 11 comprises a vehicle and an organic pigment dispersed in the vehicle, and the vehicle has a curing temperature of 150.
It is composed of two kinds of compositions of a thermosetting melamine resin at ˜300 ° C. and an epoxy resin.

In the present invention, the "thermosetting melamine resin" means a thermosetting resin obtained by an addition polymerization reaction of melamine and aldehydes, and has a thermosetting temperature of 150 to 300 ° C. Say. Specifically, "Cymel: 300, 301, 350, 303, 736, 73
8,232,238,266,235,267,28
5 ”(trade name: manufactured by Mitsui Cyanamid Co., Ltd.).

In the present invention, the "epoxy resin" means a polymer substance formed by a ring-opening reaction of an epoxy group, and specifically, "Epicoat: 815, 819, 825, 82.
7,828,834,1001,1002,1003
1004, 1007 ”(trade name: manufactured by Yuka Shell Epoxy Co., Ltd.).

In the present invention, the "printability viscosity" means a viscosity necessary and sufficient for printing a printing pattern (image line) satisfactorily, specifically, 25 Pa.s to 250 Pa.s.
Is preferred. It is not preferable to define the viscosity as described above, because if the viscosity is 25 Pa.s or less, it may cause scattering to other than the printed pattern, and 250 P
If the viscosity exceeds as, the ink will not be transferred smoothly from the plate to the glass and the printing pattern will be uneven.
This is because both are not preferable.

In the present invention, the "low-viscosity vehicle" means a vehicle having a viscosity lower than the above printability viscosity, specifically,
It is preferably 0.5 Pa.s to 25 Pa.s. Also,
The “high-viscosity vehicle” refers to a vehicle having a viscosity higher than the above printability viscosity, specifically, 250 Pa.s-100.
It is preferably 0 Pa.s. In order to obtain the above-mentioned low-viscosity vehicle and high-viscosity vehicle, the above-mentioned various thermosetting melamine resins and epoxy resins may be appropriately combined.

In the present invention, a vehicle having a printable viscosity obtained by appropriately mixing the "low viscosity vehicle" and the "high viscosity vehicle" is used, and the organic pigment is mixed and dispersed therein. Incidentally, in order to improve the smoothness of the color filter surface, higher alcohol is added to a part of the above raw material as necessary, and the mixture is reacted to form a vehicle,
In some cases, the organic pigment is mixed and dispersed, but the addition of the higher alcohol here is not the addition as a conventionally used viscosity adjusting solvent and does not have a function as a solvent.

In the present invention, "organic pigment" means a desired known yellow, orange, red, violet, etc. for a color filter used in a color display device such as a color liquid crystal display device, a color facsimile or a color video camera. Organic pigments of blue, green, brown, black, etc. Moreover, you may mix | blend dispersion aids, such as an activator, as needed.

Since the ink containing the vehicle having a printable viscosity does not contain any other solvent, it does not change with time during printing and can be continuously printed under steady conditions. Here, the steady condition means that the conditions other than the ink viscosity (for example, the ink supply amount by the dispenser, the number of times of transfer) are constant.

Test Example A test example showing the effect of the present invention will be described below. After obtaining a low-viscosity vehicle and a high-viscosity vehicle using the vehicle of the following composition, a color filter layer is formed on a substrate, and the obtained color filter layer is printed for a long time to obtain a printing pattern property. The quality was compared. The results are shown in "Table 1".

(Composition) Melamine resin: "Cymel 232" ((trade name) manufactured by Mitsui Cyanamid Co., Ltd .: curing temperature 180 ° C.) Epoxy resin: "Epicoat 1001" ((trade name)
Yuka Shell Epoxy Co., Ltd.) Higher alcohol: "Dia Doll" ((trade name) manufactured by Mitsubishi Kasei Co., Ltd.): Boiling point 274 to 300 ° C, mixture of C ₁₃ alcohol and C ₁₅ alcohol)

[0022]

[Table 1]

Next, it was tested whether there was a change in the printed pattern by the method of mixing the vehicles.

In Test Example 2 using the above composition, an ink was prepared by mixing the three and dispersing the pigment to obtain a filter layer A. In Test Example 3, was mixed in advance to obtain a varnish, and then a pigment was dispersed in the varnish to prepare an ink to obtain a filter layer B. The print patterns of the obtained filter layers A and B were examined.

As a result, the change in the printed pattern was smaller in Test Example 3 than in Test Example 2. This is because if the degassing is suppressed by a preliminary reaction in advance and then the pigment is dispersed, the composition of the vehicle is stabilized and even if continuous printing is performed, the composition does not change much and a good pattern can be formed. I think that the.

Therefore, when the varnish is obtained by the preliminary reaction, it is possible to form a good filter layer having a smaller change with time.

[0027]

EXAMPLE A preferred example of the present invention will be described below.

(Example 1) As the melamine resin, "Cymel 266" manufactured by Mitsui Cyanamide Co., Ltd., and as the epoxy resin, "Epicoat 828" manufactured by Yuka Shell Epoxy Co., Ltd. were used. A low viscosity vehicle (1.3 Pa.s) was obtained with the mixing ratio of 4: 1. As a melamine resin, Mitsui Cyanamid Co., Ltd.
"Cymel 238" manufactured by Yuka Shell Epoxy Co., Ltd. and "Epicoat 1007" manufactured by Yuka Shell Epoxy Co., Ltd. are used as the epoxy resin, and the melamine resin and the epoxy resin are mixed at a ratio of 4: 1. 150 times at a time to dissolve with epoxy resin
The mixture was heated to ℃ and a high-viscosity vehicle (500 Pa.s) was obtained. The low-viscosity vehicle and the high-viscosity vehicle thus produced were mixed at a ratio of 1: 1 and the weight change with time was left for 8 hours under the same conditions as on the ink plate of a lithographic printing machine. It is shown in. The organic pigment was added to the vehicle thus prepared to form an ink as shown in the following formulation, which was offset-printed on a glass substrate by a lithographic printing machine.
A color filter was manufactured by heat curing at 0 ° C. for 1 hour. Preparation of Ink (For Red Ink) The following composition was bound with three rolls to prepare a red ink.・ High viscosity vehicle 37.5g ・ Low viscosity vehicle 37.5g ・ Pigment Chromophtal red (Chiba Geigy) 20g Symuler Fast Yellow 4181 (Dainippon Ink and Chemicals) 5g ・ Silane coupling agent KBM602 (Shin-Etsu Silicone) 0. 2% by weight ・ 40% paratoluenesulfonic acid IPA solution 0.1% by weight

As the melamine resin, "Cymel 232" manufactured by Mitsui Cyanamid Co., Ltd., and as the epoxy resin,
Yuka Shell Epoxy Co., Ltd. "Epicoat 100
1 ”,“ Dia Doll ”manufactured by Mitsubishi Kasei Co., Ltd. is used as the higher alcohol, and melamine resin: epoxy resin is mixed at a ratio of 4: 1 (240 g: 60 g).
When heated to 100 ° C, add 20 parts of higher alcohol.
wt%, 0.1 wt% of a 40% isopropyl alcohol solution of paratoluenesulfonic acid as a catalyst is added. After that, the mixture is kept at 130 ° C. for 1 hour to carry out a preliminary reaction to distill 20 ml of a low boiling point substance, and a low viscosity vehicle (20 Pa.s
) Got. As melamine resin, "Cymel 232" manufactured by Mitsui Cyanamid Co., Ltd., as epoxy resin,
Yuka Shell Epoxy Co., Ltd. "Epicoat 100
1 ”,“ Dia Doll ”manufactured by Mitsubishi Kasei Co., Ltd. is used as the higher alcohol, and melamine resin: epoxy resin is mixed at a ratio of 4: 1 (240 g: 60 g).
When heated to 100 ° C, add 20w of diamond doll.
t%, 0.1 wt% of a 40% isopropyl alcohol solution of paratoluenesulfonic acid as a catalyst is added. Then 1
The mixture was kept at 80 ° C. for 1 hour and 30 ml of a low boiling point substance was distilled off to obtain a high viscosity vehicle (320 Pa.s). The mixing ratio of the low-viscosity vehicle and the high-viscosity vehicle used in the printing ink is arbitrarily determined to a viscosity that meets the printability condition. An organic pigment was added to the vehicle thus formed to form an ink, which was printed on glass by offset printing and heat-cured at 230 ° C. for 1 hour to produce a color filter. The flatness of the filter surface was improved by the addition of higher boiling higher alcohol.

[0030]

As described above with reference to the embodiments, in the prior art, continuous printing was not possible under steady conditions due to the evaporation of the solvent. However, in the ink using the color filter vehicle of the present invention, Since no solvent is used, the viscosity does not change over time during printing, and continuous printing of color filters is possible under stable printing conditions.

[Brief description of drawings]

FIG. 1 is a schematic view of a color filter according to the present invention.

FIG. 2 is a graph showing the weight change of the vehicle obtained in the example.

[Explanation of symbols]

 10 Filter 11 Substrate 12 Color Filter Layer 13 Transparent Electrode

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[Procedure amendment]

[Submission date] October 22, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction content]

(Example 1) "Cymel 266" manufactured by Mitsui Cyanamid Co., Ltd. was used as the melamine resin, and "Epicoat 8" manufactured by Yuka Shell Epoxy Co., Ltd. was used as the epoxy resin.
28 ”was used and the mixing ratio of the melamine resin and the epoxy resin was set to 4: 1 to obtain a low viscosity vehicle (1.3 Pa.s). As the melamine resin, "Cymel 238" manufactured by Mitsui Cyanamid Co., Ltd., and as the epoxy resin, "Epicoat 1007" manufactured by Yuka Shell Epoxy Co., Ltd. are used, and the mixing ratio of the melamine resin and the epoxy resin is 4: 1. Mix in proportions. In order to dissolve it with the epoxy resin, it was once heated to 150 ° C. to obtain a high-viscosity vehicle (500 Pa.s). The low-viscosity vehicle and the high-viscosity vehicle thus produced were mixed at a ratio of 1: 1 and the weight change with time was left for 8 hours under the same conditions as on the ink plate of a lithographic printing machine. It is shown in. An organic pigment was added to the thus-prepared vehicle as described below to form an ink, which was offset-printed on a glass substrate by a lithographic printing machine and then heat-cured at 230 ° C. for 1 hour to produce a color filter. Preparation of Ink (For Red Ink) The following formulation was kneaded with a three-roll to prepare a red ink. And high viscosity vehicles 37.5 g, low viscosity vehicle 37.5 g · Pigment Chromophthal Red (Ciba Geigy) 20 g Symuler Fast Yellow 4181 (Dainippon Ink and Chemicals, Inc.) 5 g · Silane coupling agent KBM602 (manufactured by Shin-Etsu Silicone) 0. 2% by weight ・ 40% paratoluenesulfonic acid IPA solution 0.1% by weight

Claims (3)

[Claims] 1. A vehicle having a viscosity lower than a printability viscosity,
An ink comprising a vehicle prepared by mixing only a vehicle having a viscosity higher than the printability viscosity and an organic pigment dispersed in the vehicle, and printed by appropriately patterning a predetermined color on a substrate. Color filter. 2. The color filter according to claim 1, wherein the vehicle is preliminarily reacted in advance. 3. The color filter according to claim 1, wherein the printability viscosity is 25 Pa.s at 22 ° C.
250 Pa.s and the viscosity of the low viscosity vehicle is 0.5 Pa.s.
s 〜25Pa.s, the viscosity of high viscosity vehicle is 250Pa.s
A color filter characterized by having a thickness of up to 1000 Pa.s.