JP2002341549A - Method for forming multicolor pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color filter for a reflection and transmission type LCD panel in which pixels having regions of different thickness can be formed by applying a photosensitive resin composition on a substrate and exposing the composition to light through the top and back sides of the substrate. SOLUTION: A multicolor pattern is formed by repeating twice or more times the process including (1) a process of forming a photosensitive resin composition layer on the substrate, (2) a process of exposing through the substrate side and the photosensitive resin composition layer side to form a pattern and (3) a process of developing. The color filter for a reflection and transmission type LCD panel can be easily formed by the method for forming a multicolor pattern featuring that the composition layer is exposed in such a manner that a region exposed only through the substrate side to form the pattern is present.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a multicolor pattern suitable for use in a liquid crystal color display or the like, in particular, a liquid crystal color display for both reflection and transmission.

[0002]

2. Description of the Related Art In recent years, a reflection type liquid crystal display has been developed as a portable terminal typified by a portable telephone. However, deterioration of display quality in a room and in a dark place has been regarded as a problem. A reflective / transmissive liquid crystal display device has been devised. The principle is that a window for transmissive display is opened in a part of the reflector, and a color filter is formed on it,
In a room or a dark place, a backlight is used to display an image in a transmission mode, and in an outdoor or the like where external light is sufficient, display is performed in a conventional reflection mode. In that case, the thicknesses of the color filters of the transmissive portion and the reflective portion were the same, and when sufficient brightness for reflective display was realized, the color purity of the transmissive portion was insufficient. On the other hand, when the color purity of the transmissive portion is sufficient, the reflective portion becomes dark.

In order to solve such a problem, attempts have been made to improve the display quality by changing the thickness or hue of the color filters of the transmission part and the reflection part, but the process is complicated and the cost is increased. .

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a manufacturing method capable of easily forming a color filter used in a reflective / transmissive liquid crystal display device in view of the above problems.

[0005]

(1) Step of providing a photosensitive resin composition layer on a substrate (2) Step of pattern exposure from both the substrate side and the photosensitive resin composition layer side (3) Developing A multicolor pattern forming method formed by repeating a process including at least two times at least two times, wherein the multicolor pattern is exposed so that an area of only the pattern exposure from the substrate side exists in the above (2). The above object has been achieved by a forming method.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a substrate having a thickness of 0.1 to
A photosensitive resin composition layer is provided on a 2.0 mm glass substrate or a polymer film such as polyethersulfone, polyarylate, or polycarbonate having a thickness of 10 to 1000 μm, and exposure from the substrate side and the photosensitive resin composition side is performed. Then, patterns having different thicknesses are formed in the same pixel on the substrate by development. This step is repeated a plurality of times to form a multicolor pattern. As the photosensitive resin composition to be used, all known photosensitive resins described in, for example, Japanese Patent Application No. 82262/1990 can be used. Specific examples include a photosensitive resin composition comprising a negative diazo resin and a binder, a photopolymerizable composition, a photosensitive resin composition comprising an azide compound and a binder, and a cinnamic acid type photosensitive resin composition. Among them, a photopolymerizable resin is particularly preferable. The photopolymerizable resin contains a photopolymerization initiator, a photopolymerizable monomer and a binder as basic components.

As the photosensitive resin composition, those which can be developed with an aqueous alkali solution and those which can be developed with an organic solvent are known, but from the viewpoint of preventing pollution and ensuring work safety, an alkaline aqueous solution is preferred. Those that can be developed are preferred.

[0008] Red, green, and blue pigments, which are the constituent colors of a color filter, are further added to the photosensitive resin composition layer. Preferred examples thereof include carmine 6B.
(C.I. 12490), phthalocyanine green (C.I. 74260), phthalocyanine blue (C.I.
I. 74160). The content of the pigment in the colored photosensitive resin composition is 1 to 30% by weight.
It is preferable that More preferably 5 to 20% by weight
It is.

The thickness of the photosensitive resin composition layer is determined by the thickness finally formed on the color filter. The thickness of each colored layer is preferably from 0.1 to 5 μm, more preferably from 0.3 to 4 μm, in consideration of the color depth and developability of the layer. As a preferred embodiment of the present invention, as a method of providing a photosensitive resin composition on a substrate, there are a coating method, a printing method, a transfer method and the like.
The transfer method is particularly preferred because of the simplicity of the process. The transfer material for a color filter will be described. The transfer material for a color filter is an image forming material in which a colored photosensitive resin composition layer is provided on a temporary support.
It is necessary that the temporary support for the colored photosensitive resin composition layer used in the present invention has flexibility and does not cause significant deformation, shrinkage or elongation even under pressure or under pressure and heat. It is. Examples of such a support include a polyethylene terephthalate film, a cellulose triacetate film, a polystyrene film, and a polycarbonate film. Biaxially oriented polyethylene terephthalate films are particularly preferred.

On the temporary support, a colored photosensitive resin composition layer is desirably provided directly or via an intermediate layer having ultraviolet transmittance and low oxygen permeability. Further, it is preferable to provide a thermoplastic resin layer for the purpose of avoiding air bubbles during transfer. In that case, it is preferable to laminate the temporary support, the thermoplastic resin layer, the intermediate layer, and the photosensitive resin composition layer in this order. These layers can be produced by dissolving the material constituting the layers in an appropriate solvent, and applying and drying the same. At this time, in the case of multi-layer coating on an already formed layer, it is necessary that the solvent does not attack the lower layer, but these solvents can be appropriately selected by those skilled in the art. .

The intermediate layer is formed by adhering the colored photosensitive resin composition layer to the transparent substrate, then peeling off the temporary support, and performing pattern exposure to the photocuring reaction in the colored photosensitive resin composition layer. It is provided as a barrier layer for preventing diffusion of oxygen from the air, which hinders the diffusion, and for preventing the thermoplastic resin layer and the photosensitive resin composition layer from being mixed when three layers are laminated. Therefore, it is preferable that the layer cannot be mechanically peeled off from the colored photosensitive resin composition layer and has high oxygen blocking ability.

Such an intermediate layer is formed by applying a solution of a polymer directly onto a temporary support or through a thermoplastic resin layer. Suitable polymers for use in the intermediate layer include JP-B-46-32714 and JP-B-5640.
No. 824, polyvinyl ether / maleic anhydride polymers, water-soluble salts of carboxyalkyl cellulose, water-soluble cellulose ethers, water-soluble salts of carboxyalkyl starch, polyvinyl alcohol, polyvinyl pyrrolidone, various types Polyacrylamides, various water-soluble polyamides, water-soluble salts of polyacrylic acid, gelatin, ethylene oxide polymers, water-soluble salts of the group consisting of various starches and the like, copolymers of styrene / maleic acid, And maleate resins, and two of these
Combinations of more than one species are mentioned. Particularly preferred is a combination of polyvinyl alcohol and polyvinyl pyridone, and polyvinyl alcohol having a saponification rate of 80% or more is preferred.

The content of the polymer such as polyvinylpyrrolidone is preferably 1% by weight to 75% by weight of the solid content of the intermediate layer.
It is more preferably 1% to 60% by weight, and still more preferably 10% to 50% by weight. If it is less than 1% by weight, sufficient adhesion to the photosensitive resin layer cannot be obtained, and if it exceeds 75% by weight, the oxygen barrier ability is reduced. The thickness of the intermediate layer is very thin, about 0.1-5 μm, especially 0.2-3 μm.
When the thickness of the intermediate layer is less than 0.1 μm, the oxygen permeability of the intermediate layer is too high, and when it exceeds 5 μm, it takes too much time during development or removal of the intermediate layer.

The resin constituting the thermoplastic resin layer preferably has a substantial softening point of 80 ° C. or less. As the alkali-soluble thermoplastic resin having a softening point of 80 ° C. or less,
Saponified product of copolymer of ethylene and acrylate, saponified product of styrene and (meth) acrylate copolymer, saponified product of vinyltoluene and (meth) acrylate copolymer, poly (meth) acrylic acid Preferably, at least one is selected from esters, saponified (meth) acrylate copolymers such as butyl (meth) acrylate and vinyl acetate, and the like. Edited by the Plastic Molding Industry Federation, published by the Industrial Research Council, October 1968
Among the organic polymers having a softening point of about 80 ° C. or lower, which are soluble in an aqueous alkali solution, can be used. Also, in the case of an organic polymer substance having a softening point exceeding 80 ° C., various plasticizers compatible with the polymer substance are added to the organic polymer substance to increase the substantial softening point to 80 ° C.
It is also possible to lower the temperature below ° C.

In order to adjust the adhesive strength between these organic polymer substances and the temporary support, the organic polymer substance has a substantial softening point of 80%.
It is possible to add various polymers, supercooled substances, adhesion improvers or surfactants, release agents and the like within a range not exceeding ℃. Specific examples of preferred plasticizers include polypropylene glycol, polyethylene glycol, dioctyl phthalate, diheptyl phthalate, dibutyl phthalate, tricresyl phosphate, cresyl diphenyl phosphate, and biphenyl diphenyl phosphate. The thickness of the thermoplastic resin layer is 6μ
m or more is preferable. The reason for this is that if the thickness of the thermoplastic resin layer is less than 6 μm, it is not possible to completely absorb the irregularities of the substrate having a thickness of 1 μm or more, and air bubbles are easily generated between the substrate and the substrate during transfer. The upper limit is 100 μm or less, preferably 50 μm, from the viewpoint of developability and manufacturing suitability.
m or less.

As the material of the photosensitive resin composition layer of the present invention, all known photosensitive resins described in, for example, Japanese Patent Application No. 82262/1990 can be used. Specific examples include a photosensitive resin composition comprising a negative diazo resin and a binder, a photopolymerizable composition, a photosensitive resin composition comprising an azide compound and a binder, and a cinnamic acid type photosensitive resin composition. Among them, a photopolymerizable resin is particularly preferable.
The photopolymerizable resin contains a photopolymerization initiator, a photopolymerizable monomer and a binder as basic components.

As the photosensitive resin composition, those which can be developed with an aqueous alkali solution and those which can be developed with an organic solvent are known. From the viewpoint of preventing pollution and ensuring work safety, the alkali resin aqueous solution is used. Those that can be developed are preferred.

Red, green, and blue pigments, which are the constituent colors of the color filter, are further added to the photosensitive resin composition layer. Preferred examples thereof include carmine 6B.
(C.I. 12490), phthalocyanine green (C.I. 74260), phthalocyanine blue (C.I.
I. 74160). The content of the pigment in the colored photosensitive resin composition is 1 to 30% by weight.
It is preferable that More preferably 5 to 20% by weight
It is.

The thickness of the photosensitive resin composition layer is determined by the thickness finally formed on the color filter. The thickness of each colored layer is preferably from 0.1 to 5 μm, more preferably from 0.3 to 4 μm, in consideration of the color depth and developability of the layer.

Next, a method of manufacturing a color filter using the image forming material (transfer material for color filter) prepared by the above-described method will be described. A photosensitive resin composition layer formed on a temporary support is bonded on a glass substrate having a thickness of about 1 mm or a polyethersulfone film having a thickness of about 100 μm under pressure and heat. For bonding,
Conventionally known laminators and vacuum laminators can be used, and in order to further increase productivity, an auto-cut laminator can be used. In some cases, a substrate on which a transparent pattern, a reflective film, or the like is formed in advance may be used. Thereafter, after the temporary support is peeled off, exposure is performed from the substrate side and the photosensitive resin composition side via a predetermined photomask. This exposure is performed so that there is at least an exposure area only on the substrate side. After development, the exposed area from the substrate side is not exposed to the surface due to light absorption of the photosensitive resin composition, the film thickness is reduced, and the surface exposed area is not reduced in the film thickness, and the same pixel is exposed. A pattern having a different film thickness is formed therein. The exposure amount is appropriately selected.
000 mj / cm ² is preferred. In particular, by adjusting the amount of exposure from the substrate side, the film thickness reduction rate can be appropriately selected. Since the resolution of the pattern exposure from the substrate side is reduced due to the influence of the thickness of the substrate, the edge portion of one pixel is preferably a front exposure portion. Further, it is possible to perform exposure before peeling off the temporary support, and then peel off the temporary support for development. However, in order to obtain high resolution, it is preferable to peel off before exposure.

The development is carried out in a known manner by immersing in a solvent or an aqueous developer, especially an aqueous alkaline solution, spraying the developer with a spray, rubbing with a brush, or irradiating with an ultrasonic wave. It is done by that. After the development, an ultraviolet irradiation and heat treatment step may be performed to further promote the curing reaction. By repeating the above steps a plurality of times, a color filter is formed on the substrate.

[0022]

Example 1 A coating liquid having the following formulation H1 was applied on a polyethylene terephthalate film temporary support having a thickness of 75 μm and dried to form a thermoplastic resin layer having a dry film thickness of 20 μm.

Thermoplastic resin layer formulation H1: Methyl methacrylate / 2-ethylhexyl acrylate / benzyl methacrylate / methacrylic acid copolymer (copolymer composition ratio (molar ratio) = 55 / 28.8 / 11.7 / 4) 5.5, weight average molecular weight = 90000) 15 parts by weight Polypropylene glycol diacrylate (average molecular weight = 822) 6.5 parts by weight Tetraethylene glycol dimethacrylate 1.5 parts by weight p-toluenesulfonamide 0.5 parts by weight Benzophenone 1. 0 parts by weight Methyl ethyl ketone 30 parts by weight

Next, the following formulation B1 was placed on the thermoplastic resin layer.
Was applied and dried to form an intermediate layer.

Intermediate layer formulation B1: Polyvinyl alcohol (PVA205 manufactured by Kuraray Co., Ltd., saponification ratio = 80%) 130 parts by weight Polyvinylpyrrolidone (PVP, K-90 manufactured by GAF Corporation) 60 parts by weight Fluorinated surfactant (Asahi Glass) Surflon S-131 manufactured by Corporation) 10 parts by weight Distilled water 3350 parts by weight

On the temporary support having the thermoplastic resin layer and the intermediate layer, a red (R)
Layers), green (for the G layer), and blue (for the B layer) photosensitive solutions of three colors were applied and dried to form a colored photosensitive resin composition layer having a dry film thickness of 2.0 μm.

[0027]

[Table 1]

The thickness and thickness unevenness (50 cm) of the photosensitive resin composition layers of the three colors of R, G, and B thus produced are described.
× 50 cm area) is R: 2.0 ± 0.0, respectively.
8 μm, G: 2.0 ± 0.09 μm, B: 2.0 ± 0.
08 μm.

Further, a cover sheet of polypropylene (thickness: 12 μm) was pressed on the photosensitive resin composition layer to prepare red, blue, green and black image forming materials. Using this image forming material, a color filter was prepared by the following method. 1.1mm thick, 400mm x 300m
m, a transparent glass substrate (Corning # 7059) was washed, and a silane coupling agent (Shin-Etsu Chemical KBM-603) was used.
After being immersed in a 1% aqueous solution for 3 minutes, it was washed with pure water for 30 seconds to remove excess silane coupling agent, drained, and heat-treated in an oven at 110 ° C. for 20 minutes. The coating sheet of the red image forming material was peeled off, and the photosensitive resin composition layer surface was treated with a silane coupling agent on a transparent glass substrate.
Pressure by using ^{24) (10kg / cm 2)} , heating the bonding, followed by peeling at the interface between the temporary support and the thermoplastic resin layer was removed temporary support. Next, 50 mj / cm ² and 20 mj / cm ² were respectively exposed from the substrate side and the photosensitive resin composition side via predetermined photomasks. Thereafter, developed by PD1, CD1, SD1 (manufactured by Fuji Photo Film Co. alkali developer, respectively), after removing the unnecessary portion, the ultraviolet from the opposite side of the color filter forming surface by using a super high pressure mercury lamp at 300 mj / cm ² Irradiation and heat treatment were further performed at 220 ° C. for 20 minutes to form a red pixel pattern on the transparent glass substrate. The obtained red pixel had a thickness of 0.8 μm in the exposed area only on the substrate side and a thickness of 1.7 μ in the exposed area from the photosensitive resin composition side. Subsequently, a green image forming material is attached to the glass substrate on which the red pixel pattern is formed in the same manner as described above,
Peeling, exposure, development, and post exposure were performed to form a green pixel pattern. The same process was repeated with a blue image forming material to form a color filter on a transparent glass substrate.
Each of the green and blue pixels had a film thickness of 0.8 μm in the exposed area only on the substrate side and a film thickness of 1.7 μ in the exposed area from the photosensitive resin composition side. FIG. 1 is a sectional view of a pixel pattern obtained for each of R, G, and B. In FIG. 1, reference numeral 10 denotes a transparent glass substrate.

Example 2 The same procedure as in Example 1 was carried out except that the exposure amount from the substrate side was 20 mj / cm ² . The same results as in Example 1 were obtained except that the film thickness of the exposure area only on the substrate side of the obtained RGB pixels was 0.4 μm.

Example 3 Example 3 was carried out in the same manner as in Example 1 except that exposure was performed by changing a predetermined photomask pattern from the substrate side and the photosensitive resin composition side, respectively. The film thickness of the obtained pattern is the same as that in Example 1, and FIG. 2 shows a cross-sectional view of the obtained pixel pattern of each of R, G, and B. In FIG. 2, reference numeral 10 denotes a transparent glass substrate.

Example 4 The same procedure as in Example 3 was carried out except that the exposure amount from the substrate side was 20 mj / cm ² . The same result as in Example 3 was obtained, except that the film thickness of the exposure area only on the substrate side of the obtained RGB pixels was 0.4 μm.

Example 5 Thickness of 0.9 μm in thickness with a transparent pixel pattern previously formed
A 5 μm polyethersulfone film substrate was used, the exposure area from the substrate side was matched with the transparent pixel area, and the heat treatment temperature was 150 ° C. Other than that, it carried out similarly to Example 1. The obtained film thickness was the same as that of Example 1, and FIG. 3 shows a cross-sectional view of the R, G, and B pixel patterns. 3, reference numeral 10 denotes a transparent glass substrate, and reference numeral 12 denotes a transparent pattern. In this case, the flatness of the CF pixel was good.

[0034]

According to the present invention, patterns having different thicknesses are formed in the same pixel by a simple method, and the cost of a liquid crystal panel for both reflection and transmission can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a pixel pattern obtained in Example 1 of the present invention.

FIG. 2 is a sectional view of a pixel pattern obtained in Example 3 of the present invention.

FIG. 3 is a sectional view of a pixel pattern obtained in Example 5 of the present invention.

[Explanation of symbols]

 10 Transparent glass substrate 12 Transparent pattern

Claims (3)

[Claims] (1) a step of providing a photosensitive resin composition layer on a substrate; (2) a step of pattern exposure from both the substrate side and the photosensitive resin composition layer side; and (3) a developing step. In the multicolor pattern forming method formed by repeating the process two or more times, the multicolor pattern forming method according to the above (2), wherein the exposure is performed such that an area of only the pattern exposure from the substrate side exists. 2. The method according to claim 1, wherein the step of providing a photosensitive resin composition layer on the substrate is a step of using a photosensitive transfer material. 3. The multicolor pattern forming method according to claim 1, wherein the same pixel has a thickness difference of 1: 0.9 to 1: 0.1.