KR19980028618A - Manufacturing method of new color filter for liquid crystal display - Google Patents

Abstract

As a method of forming a color layer by a manufacturing method different from a conventional method of manufacturing a color filter, a technique of forming a coating and a thin film pattern by a dry process when forming a color layer including a black matrix and a red, green, and blue colored layer. A transfer film comprising a support film, a light-to-heat conversion layer formed on the support film, and a transfer layer formed on the light-to-heat conversion layer by applying a laser transfer technique based on the transfer layer to the substrate for a color filter To a color filter substrate by transferring the portion to be transferred from the transfer film to the color filter substrate by heating the supporting film with a light source, and comparing the color characteristics of the conventional color filter with a simple and economical process. It provides a method for producing a color filter having the same or more color characteristics when.

Description

Manufacturing method of new color filter for liquid crystal display

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display, and more particularly, in a liquid crystal display forming red, green, and blue color layers as a means for implementing the color of the liquid crystal display, a color filter is used as one of two glass substrates. It is employed as an important means of expressing. A general color filter includes a glass substrate 11, a black matrix 33, a red, green, blue colored layer 31, an overcoat layer 35, and a transparent electrode (ITO) thereon as shown in FIG. 3A. : 37). Recently, a thin film transistor (TFT) liquid crystal display color filter as shown in FIG. 3B is slightly changed in the structure of FIG. 3A so that the transparent electrode 37 directly on the color layers 31 and 33 without the smooth protective layer 35. Also used to form.

Conventional methods for manufacturing color filters include various methods, and representative examples thereof include pigment dispersion, printing, and electrodeposition. In the pigment dispersion method, each color layer is formed by using a material dispersed in a photoresist, which is a photosensitive resin, through a stepwise process such as coating, exposure, development, and baking. This method is widely used because of its excellent elaboration and good reproducibility, but the process is too long.

The printing method is a technology of forming a color layer by embedding red, green and blue inks on a printing plate, which can be manufactured using various printing methods. However, this printing method has not been widely used because it has a disadvantage that it cannot be applied to a large size display due to poor elaboration.

Electrodeposition is a method of forming a colored pigment on a transparent electrode by electroplating, which has excellent smoothness but poor color characteristics, which is used in super twisted nematic (STN) displays but is not widely used in thin film transistor liquid crystal displays. I can't.

The present invention has been made to solve the above problems of the prior art, an object of the present invention is to overcome the disadvantages such as the process is very long and expensive equipment when using the conventional method in the production of color filters of the liquid crystal display Thus, the process is short and the color layer including the black matrix and the red, green and blue colored layers can be easily and precisely formed to provide a method usable for the liquid crystal display.

1 is a cross-sectional view schematically showing the structure of the film and the substrate after the transfer layer for a liquid crystal display according to an embodiment of the present invention.

Figure 2 is a cross-sectional view showing the structure of a transfer film for a liquid crystal display according to an embodiment of the present invention.

Figure 3a is a schematic cross-sectional view showing the structure of a general color filter.

Fig. 3B is a sectional view schematically showing the structure of a color filter in a thin film transistor liquid crystal display.

Explanation of symbols on the main parts of the drawings

9: light source 11: substrate 13: transfer layer 15: light-to-heat conversion layer

17: support film 31: colored layer 33: black matrix

35: smooth protective layer 37: transparent electrode

The present invention has the following configuration to achieve the above object of the present invention.

In the present invention, a base substrate 17, a light-heat conversable layer 15 formed on the support film, and a transfer layer formed on the light-heat converting layer. It provides a transfer film for a color filter comprising a (13).

The support film 17 is a transparent polymer selected from the group consisting of polyester, polyacrylic, polyepoxy, polyethylene, polypropylene, and polystyrene polymers, and preferably has a thickness of 10 to 500 µm.

The light-to-heat conversion layer 15 is selected from the group consisting of a metal having high light absorption in the infrared-visible light region, an oxide of the metal and a sulfide of the metal, and preferably has a thickness of 100 to 5000 kPa. In addition, the light-to-heat conversion layer 15 is selected from the group consisting of carbon black pigment, graphite pigment, a polymer in which the infrared dye is dispersed, it is preferable that the thickness of 0.1 ~ 10㎛.

The transfer layer 13 is a color layer, and the color layer is preferably prepared by adding a pigment or dye to a dispersant, dispersing it in a solvent, and mixing a binding polymer and / or an additive. The color layer preferably includes a black matrix, a red colored layer, a green colored layer, and a blue colored layer.

It is preferable that said binding polymer is an acryl-type, a polyimide-type, a polyepoxy clock, an acryl epoxy clock, and a polyester-type polymer.

In the present invention, the transfer film comprising a support film, a light-heat conversion layer formed on the support film and the transfer layer formed on the light-heat conversion layer is in close contact with the transfer layer to the color filter substrate It provides a color filter manufacturing method comprising the step of transferring the portion to be transferred from the transfer film to the color filter substrate by heating the support film using a light source.

The light source is preferably selected from the group consisting of a solid state laser, a gas laser, a semiconductor laser, a dye laser, an excimer laser, a xenon lamp, and a flash lamp.

The transfer film is preferably a semi-reflective coating treatment of the transfer layer or further comprises a gas generating layer between the light-heat conversion layer and the transfer layer.

The present invention provides a method for forming a color layer by a manufacturing method different from that of a conventional color filter, which is a wet process when forming a color layer including a black matrix and a red, green, and blue colored layer. It is based on the technology of forming a coating and thin film pattern by a dry process, and the development of such technology has not been developed so far. This technology uses laser induced transfer technology, which is a technology that can directly transfer color ink materials, among various methods of laser color image, which is a technique for printing fine colors, as a color filter technology. Known as laser ablation or thermal melt transfer technology, this color imaging technique is described in US Pat. 5,156,938, 5,171,650, 5,256,506, 5,089,372, 5,459,016, 5,409,883, 5,326,619, 5,308,737, 5,278,023. The present invention is applied to a method of forming a color layer of a color filter by applying a heat transfer technique using the laser.

As shown in FIG. 1, the transfer film as shown in FIG. 2 is brought into close contact with the substrate 11, such as an organic substrate, and the portion to be transferred is heated with a laser or other light source l to transfer the substrate 13 to the substrate 11. This is transferred to obtain a fine pattern. In other words, in the structure consisting of the light source l , the transfer film, and the substrate 11, the light-heat conversion layer 15 of the transfer film is heated by the light source to melt or gas the transfer layer 13 by heating. By generation, the pattern of the transfer layer 13 to be transferred is transferred to the substrate with a predetermined thickness to form a fine pattern.

The substrate may be a glass substrate, but other plastic or general purpose substrates may be used.

The light source usable in the present invention can be a laser, a Xenon lamp, a flash lamp, and many other light sources. The best is a laser, which is a solid, gas, semiconductor, dye, and excimer laser. All general purpose lasers can be used. In addition, the shape of the beam generally uses a circular beam, but all types of beams can be used. In addition, the size and energy of the laser beam used can be variously changed depending on the width of the pattern width and the sensitivity of the film. The energy distribution used in the present invention also uses a general Gaussian distribution, but can be changed as necessary.

The structure of the transfer film is composed of a support film, a light-heat conversion layer and a transfer layer. The support film 17 is a polymer film having transparency, and mainly uses a polyester-based polyethylene phthalate film, and is generally used for polyester, polyacrylic, polyepoxy, polyethylene, polypropylene, and polystyrene polymers. Film is used.

The light-heat conversion layer 15 of the present invention uses a metal film and an organic film as a material capable of absorbing laser light in the infrared-visible light region. All metal films, metal oxide films, and metal sulfide films having high light absorption in the infrared-visible light region can be used as the metal film, and in particular, aluminum and aluminum oxide films are used. As the organic film, carbon black pigment, graphite pigment or infrared ray can be used. Dye is used by dispersing in polymer. In the case of a metal film, a film having a thickness of 100 to 5000 kPa is used through a vacuum deposition method, and an organic film is coated with a thickness of 0.1 to 10 μm. In the case of a metal film, the coating method can be easily formed by e-beam deposition or sputtering, in addition to vacuum deposition, and various other methods are possible. In the case of the organic film coating method is a general film coating method using a solution dispersed in a solvent using an extrusion (extrusion), spin (spin) and knife (knife) coating method is used.

In addition, the transfer layer 13 of the present invention is used by coating a color layer including a black matrix, red, green and blue layers. The color layer introduced and used in the transfer layer is used after mixing a pigment or dye as a mixed component in a solvent by adding a dispersant and then adding a binder polymer and other additives. In this case, the coating method may be a general film coating method such as extrusion, spin, and knife coating method, and is used by coating at a thickness of 0.1 to 2.0 μm. The binding polymer used in this transfer layer can be used as long as it is a polymer having general transparency and heat resistance such as acrylic, polyimide, polyepoxy, acrylic epoxy and polyester. Pigments or dyes used in this transfer layer can be any pigments or dyes that can exhibit the color characteristics of the color filter, and yellow pigments or dyes can be added to the red or green color to match the color tone, and the blue color is violet. Pigments and dyes can be added and used. In the present invention, the additive may be used by adding a plasticizer or a low molecular weight organic material for the purpose of improving transfer characteristics during transfer, and may also use a material such as a cross-linking agent for the purpose of enhancing the curing property after heat treatment. It may be added, and additives may be added for other purposes.

The structure of the film used in the present invention uses the structure as shown in Figure 2 as the most basic structure and can be used by changing the structure of the film according to various uses in the film of the basic structure. For example, anti-reflection coating may be performed to prevent degradation of the transfer layer due to reflection, and a gas generating layer under the light-heat conversion layer may be used to increase the sensitivity of the film. It is also possible to introduce and use (gas producing layer).

The following presents a preferred embodiment to aid the understanding of the present invention. However, the following examples are merely provided to more easily understand the present invention, and the present invention is not limited to the following examples.

EXAMPLE

Example

Preparation of Transfer Film

The light-to-heat conversion layer 15 dispersed according to the composition of Table 1 below on the PET support film 200㎛ was hardened by extrusion coating to form a thickness of 3㎛.

TABLE 1

Chemical composition Weight ratio Binder polymer: 20% methyl ethyl ketone solution of Nichigo Polyester LP-011 300 Carbon black 10 Solvent: Methyl ethyl ketone 327

After diluting the composition compounds shown in Table 2 below in the deionized water on the light-to-heat conversion layer 15, the color transfer layer was extrusion coated to form a thickness of 1㎛.

TABLE 2

Chemical composition of the transfer layer Red layer weight (g) Green layer weight (g) Blue layer weight (g) Acrylic resin ^{* 1} 750 750 750 Triwthylamine 250 250 250 Chromophthal Red ^{* 2} 350 0 - Heliogen green ( ³ ) - 400 - Heliogen blue ( ⁴ ) - - 270 Ennceprint yellow ^{* 5} 150 100 - Paliogen Violet ( ⁶ ) - 30

* 1: ARON S-4030, Toyose Corporation (Toagose Chemical Industry Co. Ltd.)

* 2: Shiba Kaigi company

* 3: BASF company

* 4: BASF company

* 5: BASF company

* 6: BASF company

Warrior

The film prepared above was formed with a fine pattern in the size of a niobium-Yag 8W laser 100 탆 beam.

Comparative example

First, a black matrix 33 was formed on the glass substrate 11 by sputtering the chromium to a thickness of 1000 to 2000 mm 3. Disperse the pigment on the glass substrate 11 on which the black matrix 33 is formed, apply a colored photosensitive resist resin, soft bake on a hot plate at 60 to 120 ° C., and develop with a developer for 2 to 3 minutes. Then, the resultant was rinsed with deionized water for 1 to 2 minutes and then cured at 20 to 220 ° C. for 1 hour to form a red filter layer as a first color filter layer having optimized red spectroscopic characteristics. In the same manner as the first color filter layer, the color layer pattern was formed such that the green pattern as the second color filter layer and the blue pattern as the third color filter layer were sequentially overlapped with the black matrix between the black matrices. Next, an indium tin oxide transparent electrode film was formed on the black matrix and the colored layer to a thickness of about 500 to 3000 GPa to prepare a color filter substrate. A cross-sectional view of the manufactured color filter substrate is shown in Figure 3b.

As described above, the color filter substrate for the liquid crystal display according to the Examples and Comparative Examples of the present invention was manufactured, and the characteristics thereof were measured. As a result, Table 3 was obtained.

TABLE 3

Results of Examples and Comparative Examples

characteristic Example Comparative example Permeability (%) Red: 95% Green: 82% Blue: 82% Red: 95% Green: 80% Blue: 82% Sheet resistance (Ω / □) ^{* 1} 9.7 9.8

* 1 ： 2000 Ω transparent electrode (ITO) thickness

The manufacturing method according to the present invention can be produced at a lower cost than the existing manufacturing method in terms of cost, the process is short, and the manufacturing method is simple, and the defect rate is significantly lower than that of the conventional color filter. In addition, when the liquid crystal display is manufactured by using the color filter manufactured by the present invention, it is possible to produce a color filter having the same or more color characteristics than the color characteristics of the existing color filter and having excellent smoothness.

Claims (14)

A support film; A light-to-heat conversion layer formed on the support film; A transfer layer formed on the light-to-heat conversion layer; Transfer film for color filters containing. The transfer film of claim 1, wherein the support film is a transparent polymer selected from the group consisting of polyester, polyacrylic, polyepoxy, polyethylene, polypropylene, and polystyrene polymers. The transfer film for color filters according to claim 1, wherein the support film has a thickness of 10 to 500 μm. The transfer film of claim 1, wherein the light-to-heat conversion layer is selected from the group consisting of a metal having high light absorption in the ultraviolet-visible light region, an oxide of the metal, and a sulfide of the metal. The transfer film for color filters according to claim 4, wherein the light-to-heat conversion layer is 100 to 5000 mm thick. The transfer film of claim 1, wherein the light-to-heat conversion layer is selected from the group consisting of carbon black pigments, graphite pigments, and polymers in which infrared dyes are dispersed. The transfer film for color filters according to claim 6, wherein the light-to-heat conversion layer has a thickness of 0.1 to 10 μm. The transfer film of claim 1, wherein the transfer layer is a color layer. The transfer film of claim 8, wherein the color layer is prepared by adding a pigment or a dye to a dispersant, dispersing it in a solvent, and mixing a binding polymer and / or an additive. The transfer film of claim 8, wherein the color layer comprises a black matrix, a red colored layer, a green colored layer, and a blue colored layer. 10. The transfer film of claim 9, wherein the binding polymer is acrylic, polyimide, polyepoxy, acrylic epoxy, or polyester-based polymer. A transfer film comprising a support film, a light-to-heat conversion layer formed on the support film, and a transfer layer formed on the light-to-heat conversion layer, closely adhere to the transfer layer on the color filter substrate; Transferring the portion to be transferred from the transfer film to the color filter substrate by heating the support film using a light source; A color filter manufacturing method comprising the step. The method of claim 12, wherein the light source is selected from the group consisting of a solid laser, a gas laser, a semiconductor laser, a dye laser, an excimer laser, a xenon lamp, and a flash lamp. The method of claim 12, wherein the transfer film further comprises a semi-reflective coating of the transfer layer or a gas generating layer between the light-to-heat conversion layer and the transfer layer.