JPS63129302A - Color filter - Google Patents

Abstract

PURPOSE:To improve heat resistance by printing and forming colored layers essentially consisting of a thermosetting melamine resin of a solvent soluble type satisfying specific conditions and epoxy resin as well as a dye and dispersion aid to a desired pattern shape at a prescribed number of colors. CONSTITUTION:The thermosetting melamine resin of the solvent soluble type which does not lose transparency in a hot atmosphere of 200-300 deg.C and has >=200 deg.C peak temp. of heat generation on curing and the epoxy resin are mixed, by which the colored layers 9 imparted with the adhesiveness to a glass substrate 3 by the epoxy resin and the heat resistance and film strength imparted by the melamine resin are formed on the substrates. Direct formation of transparent conductive picture element electrodes 8 thereon is then permitted. The crosslinking reaction when the melamine resin and the epoxy resin are blended is the ring opening reaction of an epoxy ring and amino group which disperses the pigment. The colored layers 8 are formed by an intaglio or intaglio offset printing method. Org. pigments which have excellent fastness to light and heat resistance and good dispersibility in the resin are used as the dye. The heat resistance is thereby improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a color filter suitable for use in a liquid crystal cell or the like of a color liquid crystal display device. Specifically, the present invention relates to a color filter in which a colored film is formed on a substrate such as glass by an intaglio or intaglio offset printing method.

(Conventional technology) Liquid crystal? The full-color display device used has already been put into practical use, and has the characteristics of a square shape, low voltage drive, and low power consumption. Large array displays have also been put into practical use. These devices basically have red, green, and
Liquid crystal corresponding to the patterned filter layer of 6 colors of blue? Full color by driving it as an optical shutter?
This is a method of reproducing.

Many methods have been proposed for patterning filter 1-, but can they be roughly divided into photophosphorography? It can be divided into those that have been used and those that have been printed.

The former is, for example, resist 1 patterned by a well-known method.
Exchange? Can you create color patterns using dyeing, discharge printing, vapor deposition, or etching methods? On the other hand, the latter method literally forms a color pattern directly by printing. The photophosphorography method has the advantage of higher dimensional accuracy and the ability to form fine patterns than the printing method, but compared to the printing method, it has at least the following steps: resist film coating, exposure, etching, and resist film peeling. Have to repeat extra. On the other hand, the printing method can create a pattern by simply printing and drying repeatedly, so it is low cost and excellent in mass production.

Furthermore, high dimensional accuracy and smoothness due to the development of printing technology? It has become possible to print fine patterns with the same characteristics, and there is an urgent need to develop durable color filters.

(Problem that the invention seeks to solve) Liquid crystal? When a color filter is installed in a liquid crystal cell in a full-color display, it has excellent properties in terms of heat resistance, transparency, chemical resistance, transparency, and adhesion to substrates. I need. In other words, in the liquid crystal cell manufacturing process, chemical resistance is required from the cleaning process, and heat resistance is required from the alignment film formation process, transparent conductive pattern formation process, etc. Wait, regarding the formation of transparent guide turtle patterns, is it usually a liquid crystal cell? Thin film elements such as matrix thin film transistors and nonlinear elements are used as circuits that control each independently. When used, full color display is possible by providing a common electrode on the color filter, and transparent JA! When forming the model, it can be attached at room temperature. However, liquid crystal cells made by this method are extremely expensive and have a good yield. -Blade drive element? There is a method that does not use the X-Y simple matrix method, and liquid crystal? The two sandwiched substrates, the signal side electrode substrate and the scanning side electrode substrate, respectively, are connected to the X and Y sides of the pixel grid.
It is something that is formed and displayed. Is the former dyeing method using gelatin possible? However, for the latter method, is it possible to provide a transparent pixel electrode on top of the color filter 1? The reason for this is that the organic filter used for the single-layer material of the conventional dye ToM Crab filter has insufficient heat resistance, resulting in wrinkles, cracks, etc. Occur. On the other hand, although melamine resin is excellent in terms of heat resistance, it has the problem of poor adhesion to glass substrates.

(Objective of the Invention) The present invention is a low-cost printing method that has been realized through various studies in terms of heat resistance. A color filter that can be used to form a color filter, and a transparent pixel electrode can be formed directly on the filter without a protective layer? This is what we provide.

(Problem? No Means to Solve) In other words, the present invention provides transparency on a substrate in a thermal atmosphere of 200 to 500°C. Curing without loss, exothermic peak temperature of 200℃
A colored layer containing the above-mentioned solvent-oTd type thermosetting melamine resin, epoxy resin, pigment, and dispersion aid as main components is printed and formed in a desired pattern in a predetermined number of colors. This is a color filter with special features.

Is the color filter of the present invention a colored layer? It is formed by the intaglio or intaglio offset printing method, and is an organic pigment that has excellent light resistance and heat resistance, and has good dispersibility in resin. It is preferable to use

(Detailed description of the invention) Is there a color filter in Figure 1? An example of the color liquid crystal display device used? In the figure, the white t emitted from the light source
Ill be colored through polarizing plate (2) transparent substrate (31? way transparent pixel polarization (4) alignment film 15), liquid crystal (6) alignment film (7) transparent pixel electrode ffl +811a- II +91?
It is decomposed into three primary colors.

In response to the arousal signals applied to the pixel electrodes (4) and 8), the liquid crystal (6) is arranged and operates as an optical shutter due to the action of the polarizing plate U11, and the electrical signals are converted into information as three primary colors. Ru. At this time, gelatin as the colored layer (9)?
Dyed with dye? Transparent pixel polarization (8)? Colored layer (9
) had to be formed under the As a result, since the colored layer (9) is interposed between the liquid crystal 16) and the transparent pixel polarization 18), the response time of the liquid crystal to Narita 0N-OFF becomes slow, the viewing angle of the liquid crystal panel becomes narrow, and parallax increases. Color shift may also occur due to the angle of the angle.

Therefore, the performance of the color liquid crystal display @Fugu is poor. The present invention provides an 11-contact transparent pixel electrode on the colored layer (9).
Even if the color filter is formed, cracks, wrinkles,
Heat resistance and film strength that does not cause color turbidity etc. have

As a result of detailed comparative studies of various binder resins,
Epoxy resins, melamine resins, phenolic resins, polyester resins, etc. can be cited as thermosetting resins, and each has advantages and disadvantages.Epoxy resins and melamine resins are used as ink binder resins for color filters? Is it possible to satisfy all Yasugi performance f1 by mixing? I found it. Each resin? Characteristics when used alone? It is described below. Epoxy resin alone? When using an acid anhydride (hexahydrophthalic anhydride, tetrahydrophthalic anhydride) as a hardening agent when the thickness of the colored layer is 0.5μ to 3μ,
? Even if it is added, the curing agent will sublime because it is a thin film, making it impossible to obtain sufficient crosslinking density. Or amine curing agent? When used, the pot life of the ink is short and is it a cured product? Shade 4 on transmittance due to coloring? affect Melamine resin alone? When used, a three-dimensional network inertia in which the amine group is hexafunctional and complex? It is a polymer with relatively high heat resistance. While most thermoplastic resins melt at temperatures of 100 to 150°C, melamine resins melt at temperatures as high as 200 to 500°C, but have poor adhesion to glass substrates and are brittle.

So both of them? Is it possible to improve the adhesion of epoxy resin to glass substrates by mixing it? Heat resistance and film strength with melamine resin? It is now possible to form a colored layer with the same color, and to form a transparent interconnected pixel electrode directly thereon.

Melamine resin or epoxy resin? The crosslinking reaction when blended is a ring-opening reaction between the epoxy ring and the amino group. But pigment? Spread. Melamine resin and epoxy resin as binder fat for samurai? If it is added in a blended form, some crosslinking reaction will proceed during dispersion, resulting in poor storage stability of the ink. It is severely damaged and gels in a very short time. Therefore, pigment? When dispersing, melamine resin and epoxy resin are made into inks separately, and then two inks are made at the desired ratio. It is mixed. Are the two resins that can be used in the present invention less colored and have alcohol-poured acid groups? There is no problem if the epoxy resin is soluble in the solvent, but from the viewpoint of compatibility with melamine, it is preferable that the epoxy equivalent of the epoxy resin is 1000 or less. In addition, the blending ratio of melamine resin and epoxy resin is within the range of 5% to 30% by market weight of epoxy resin to melamine resin. However, as the amount of epoxy resin increases, the heat resistance deteriorates.

Below are representative examples of epoxy resins and melamine resins that can be used in the present invention. Indicated by product name.

■Bisphenol type epoxy resin Epicoat 815.819.827.828.832
．． 854.

1001. 1004.1007 (Oilized shell epoxy (4i Relily melamine resin-pan 208E-60, 20H3, 120 Cymel 350,327 (Mitsui Toatsu Chemical Co., Ltd.) Benzoguanamine cutting (a type of melamine resin) Cymel 112
Pigments that can be used in the present invention, such as 3.1125 (Mitsui Toatsu Chemical Co., Ltd.), are the same as the binder resin.

Pigments are desirable because heat resistance, chemical resistance, solvent resistance, liquid crystal resistance, and light resistance are required. Furthermore, in order to ensure proper spectrum and transparency, the pigment has a large absorption coefficient for visible light, and the average particle diameter is sufficient for visible light. Since it is necessary to select a suitable pigment, it is preferable to use pigments having a certain amount. The primary particle size of the pigment is 0.3μ from the viewpoint of transparency.
Since the desired particle diameter is preferably 0.1μ or less, the primary particle diameter of the pigment is measured using a known method such as a sand mill, a niegu, or a two-roll method. Reduce transparency and absorption coefficient a
? It is also effective to improve

The following are materials with excellent resistance to various types of pigments that can be used in the present invention. O C,I, yellow pigment, indicated by color index (C,1,) number 24.86.93.94.108
．． 109°110.117, 125, 157.13
8.

147.153.154 , 166.168C, 1, Orange pigment 36.43.51.55.59.6IC,
1, Red pigment 97.122, 125, 149.1
68.177°178.180.187.190%
192°209.215, 216 or 217°22
0. 223. 224. 226. 227.

228. 240 C,1, Violet pigment 19.23.29.30
j7゜40. 50 C,1, blue pigment 15, 15:1, 15:3,
15:4, 15:6.

22.60.64 C,1, green pigment 7,36 C',1. Brown pigment 23.25.26C', 1.
Black Pigment 7 Which solvents can be used in the present invention include the above-mentioned epoxy resin and melamine resin? Does the evaporation rate of solvent have a big influence on dissolution and printability? give. Is this ink applied to the image area of the intaglio plate? The process of transferring from the intaglio to the transfer body and the ink on the transfer body? The process of transferring to the substrate? Since the pattern is formed using the offset printing method, the reproducibility and shape collapse due to repetition are poor. In order to prevent
Does the above requirement require a mixed solvent of one or more selected from aliphatic alcohols, preferably polyhydric alcohol derivatives, having a temperature of 0°C to 260°C? Do you mean Manda Ding? I found it.

What are the names of solvents that can be used in the present invention? show.

ethylene glycol, Ethylene glycol monomethyl ether.

Ethylene glycol monoethyl ether, ethylene glycol inpropyl ether, ethylene glycol motuptyl ether.

Ethylene glycol monosil ether.

Ethylene glycol monoacetate, methoxymethoxyethanol, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether.

Diethylene glycol motubutyl ether, diethylene glycol monoacetate.

Triethylene glycol monomethyl ether.

Triethylene glycol monoethyl ether.

Propylene glycol, Propylene glycol monomethyl ether.

Propylene glycol monoethyl ether.

Propylene glycol-n-propyl ether, propylene glycol inopropyl ether.

Propylene glycol motuputyl ether.

Propylene glycol monoacetate.

1-Butoxyethoxypropanol.

Among these solvents, what is the drying rate by combining low boiling point ones with high boiling point ones and high boiling point ones with low boiling point ones? adjust. Furthermore, since the rheological properties vary somewhat depending on the solvent composition, the selection of the m agent is ultimately determined by the printing speed and the content of the pond composition.

The ink for color filters according to the present invention does not contain the resins, pigments, and solvents mentioned above. In principle, 5T can be manufactured just by kneading.
It is Noh. However, when using the same resin, the flow characteristics of the ink will differ depending on the pigment, and what is the optimal spectrum? Is there a big difference in the ink properties of each color because the pigment-containing acid of each color is different? arise. In this case, it is effective to add a dispersion aid. Does the dispersion aid improve the dispersibility of pigments?
It has the effect of improving and preventing the re-agglomeration of pigments, thus reducing the chicken tropism and reducing the ink viscosity.

It has effects such as improved permeation and smoothness of the coating film.

Examples of dispersion aids that can be used in the present invention include surfactants such as cationic active agents, anionic active agents, nonionic active agents, and organic dye derivatives. Preferably, organic dye derivatives are used. Organic pigment derivatives are derivatives of organic pigments or dyes, such as azo, phthalocyanine, quinacridone, anthraquinone, perylene, perinone, thioindigo, dioxazine, inindolinone, quinophthalone, and triphenylmethane. Substituents in metal complex salt-based organic dye compounds? It is a compound having 1 to 4. The substituent is a hydroxyl group, a carboxyl group, a sulfone group, a carbonamide group, etc., or a substituent represented by the following general formula.

-CH2-X -A (X: oxygen or sulfur atom, diaryl group) 8-Cl-I20XN ((X: alkylene group, R1, R2: hydrogen atom, alkyl group, or R4 and R2 together contain at least a nitrogen atom) heterocycle) R1 -('f(2N ((R7: alkyl group or aryl group.

R2: alkyl group or aryl group, or R1 and R
2 and at least a nitrogen atom? (R1: hydrogen atom, alkyl group).

N: alkylene group.

R2: alkyl group, alkoxyalkyl group, or cycloalkyl group.

R5=alkyl group or cycloalkyl group or R2
And R5 is at least a nitrogen atom? Note that the organic pigment and the parent organic pigment of the derivative are usually the same in terms of hue, but they do not necessarily have to be the same.

As shown in FIG. 2, the structure of the color filter is such that a black light-shielding layer (151 includes a black pigment such as carbon black or a mixed color pigment of cyan, magenta, and yellow pigments) is placed between the colored filters 41211131141 of each color. It is preferable to form a pattern using a colored composition.The light shielding layer +tS+ is also a colored filter layer (121R1
3) Is it heat resistant like i141? Is the above pigment in melamine heat-resistant resin because it is required? What was dispersed? Good to use. Color filter ink #a
Basically, there is little difference from the conventional printing ink restoration method. The ink is 200℃～230℃02～
Just by heating for 6 hours, practically sufficient mechanical strength and adhesion to the substrate can be obtained and the film can be fixed. The ink for color filters according to the present invention will be described below.

(Ink example) Mitsui Toatsu Chemical +4 [! Cynor 35
0 (product name) and the epoxy resins are diethylene glycol heptanoethyl ether and ethylene glycol motsubutyl ale, respectively. A festival made by dissolving 20% of each resin in a 2:1 mixture of solvents? Revised. Next, add the pigment and, if necessary, a dispersion aid to each of the above ingredients. In addition, three rolls are thoroughly kneaded, and red, green, and blue inks are added. manufactured respectively. As for the ratio of 1 ft of fat on both sides, is it melamine ink versus epoxy ink? 20% heavy weight was added to make the final ink.

Two kneading tests were conducted for each color with the following composition.

(All ratios are heavy electric %) Is the extender pigment Aerosil R-972 (Japan Aerosil @J)? Using. Also, what is the composition of pigments and dispersion aids for each color? It is shown below.

(For red filters) R Pigment Lionogen Red GD (Toyo Ink Seisaku I Kiki C, 1
, Pigment Red 16B) 70 parts Onogen Orange R (Toyo Ink #qtm4J (', I.

Pigment Orange 56) Mixture with 30 parts Dispersion aid Compound with the following structural formula (for green filter) L'D pigment Lionol Green 2YS (C manufactured by Toyo Ink'
, 1, Pigment Green 36) 75 copies Tori Onogen Ero-6G (East) Sheep ink production! m'4Jc, I.

Mixture with Pigment Yellow 154) 25 parts Dispersion aid The following low chlorinated copper phthalocyanine derivative n = 1.7 (for blue filter) 4D Pigment Lionau Blue ES (Toyo Ink 'EJ @ fa C
.

■, Pigment Blue 15:6) 80 parts mixture with 20 parts of Onogen Violet RL (C0 manufactured by Toyo Ink Manufacturing ■, Pigment Violet 23) ■ Dispersion aid Copper phthalocyanine derivative shown below n = 2.0 (color Manufacture of filter @) l Figure 3 shows the ink of the present invention? Use °C to print on a substrate using intaglio offset printing method? FIG. Intaglio plate (200μ width, plate depth 10μm) Ink prepared in Example 1 (IgI & applied on L171, doctor u81
After scraping off the excess ink with A9, apply blanket 12.
Intaglio on 01 + ink on 171? Transfer, Blanket 1201? Move the ink on the blanket 1 to the glass substrate 211? It is transferred onto the glass substrate 121+.

This operation? A pattern was formed by repeating each color.

As a result, the following custom order? Do you have a color filter? Created.

D spectral characteristics...shown in Figure 4 (solid line).

'■ Heat resistance: After heat treatment at 230°C for 2 hours, the change in spectral transmittance is within 5% as shown in Figure 4 (dotted chain line).

', Is it appropriate to have a film on the transparent pixel electrode... Is it possible to use a transparent conductive film on the color filter without a protective layer? Even when a transparent conductive layer ff of 10Ω/hole to 15Ω/hole is patterned by high-temperature sputtering, no cracks, wrinkles, etc. occur.

■Chemical resistance, solvent resistance... results from immersion or ultrasonic cleaning? Shown in Table 1.

Table 1 It was dipped in an ultrasonic bath for 1 minute.

Appearance immediately after pulling up ◎ → No color change, wrinkles, or cracks Peel off the cellophane ○ → Effect of the invention without peeling) The color filter made of the ink for color filters according to the present invention has a high heat resistance of the colored layer, so it can be heat-treated and filtered even at ℃. Since the spectral characteristics of the spectral characteristics do not deteriorate and the mechanical strength is improved, the conventional transparent material 14? A protective layer to provide? Although it required ℃, direct attachment is now possible. Also, since printing is possible, the process is shorter and the cost is lower than that of the photophosphorography method. can be supplied.

Furthermore, since it can be formed by a printing method as shown in FIG. 3, large color filters can be easily produced.

[Brief explanation of the drawing]

Is Figure 1 an example of a color liquid crystal display? A schematic cross-sectional view showing
Fig. 2 is an embodiment of the color filter of the present invention? FIG. 3 is a sectional view showing the ink of the present invention. Overview of printing to create color filters using? The explanatory diagram shown in Fig. 4 shows the spectroscopy of a color filter that is improved by the ink of the present invention. FIG. 111...Light source (121G31114+・
・・Colored filter single layer f2++Ill・・Polarizing plate
! 151... Light shielding layer 1311Q)... Transparent substrate
(16)...Transparent substrate (-1) f8)...Transparent pixel polarization Uη...Version +5) f71...Alignment film t
18)...Doctor 6)...LCD is 9
... Ink (9) ... Color filter 1201
...Blanket 1211...Transparent substrate

Claims (1)

[Scope of Claims] 1) A solvent-soluble thermosetting melamine resin and an epoxy resin that do not lose transparency in a hot atmosphere of 200 to 500°C and have a curing exothermic peak temperature of 200°C or higher; A color filter characterized in that it is formed by printing a colored layer containing a dye and a dispersion aid as main components in a desired pattern in a predetermined number of colors. 2) The color filter according to claim 1, wherein the dye is an organic pigment. 3) The color filter according to claim 1, wherein a transparent conductive film is directly formed on the colored layer. 4) The color filter according to claim 1, wherein the colored layer is printed by an intaglio printing method or an intaglio offset printing method.