JPH05341114A - Manufacture of color filter - Google Patents

Abstract

PURPOSE:To provide a manufacturing method of a color filter for forming a color filter with the transfer of the image forming material, which can obtain the color filter with little of discoloring of a picture element (blank). CONSTITUTION:The manufacturing method of a color filter includes the following processes: (1) a process for heating a photosensitive resin layer of the image forming material, which is obtained by providing a colored photosensitive resin layer in a temporary support body, and adhering it to a transparent base board; (2) a process for peeling off the temporary support body; (3) a process for pattern-exposing the photosensitive resin layer; (4) a process for developing the photosensitive resin layer; (5) a process for irradiating the light including a range of the wave length, which can harden the photosensitive resin layer, to the base board provided with the photosensitive resin layer formed with a pattern; (6) a process for repeating the processes (1)-(5) for respective image forming materials colored with different colors.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art A liquid crystal color filter has a structure in which red, green and blue dot-shaped images are arranged in a matrix on a transparent substrate such as glass and the boundaries thereof are divided by a black matrix. Conventionally, as a method for producing a color filter, a transparent substrate such as glass is used as a support, 1) a dyeing method, 2) a printing method, 3) JP-A-63-298304 and JP-A-63-309916.
JP-A No. 61-99103, 4) Colored photosensitive resin solution method (colored resist method) by repeating coating, exposure and development of a colored photosensitive resin solution described in JP-A No. 1-152449 and the like. And a method of sequentially transferring images formed on a temporary support onto a final or temporary support as described in JP-A No. 61-233704 or JP-A No. 61-279802, 5). Japanese Patent Laid-Open No. 61-9910
Forming a colored layer by applying a pre-colored photosensitive resin liquid described in JP-A No. 2-2980 onto a temporary support, and then directly transferring this photosensitive colored layer onto a transparent substrate, exposing and developing. It is known to form a multicolor image by a method of repeating the above. In addition, methods such as electrodeposition and vapor deposition are also known.

Next, a protective film for the purpose of physical and chemical protection of the color filter and flattening of the surface may be formed thereon. As the protective film, a highly transparent film such as an acrylic, urethane, or silicone resin film or a metal oxide film such as silicon oxide is applied by spin coating, roll coating, a printing method, etc., and if necessary. Generally, a method in which the film is left horizontal, the solvent is removed, and the resin is cured is generally used.

Further, a vacuum film forming method such as a sputtering method or a vacuum vapor deposition method is further used to form indium tin oxide (I
After forming a transparent conductive film such as TO) or tin oxide, an electrode pattern is processed by an etching method or the like to form a transparent electrode layer. The transparent electrode layer may be formed on the transparent substrate below the colored image and black matrix layer.

In the conventional main methods of forming a colored image relating to the production of color filters, 1) in the dyeing method, the photoresist coating and the partial dyeing of the dried transparent film are repeated, so that the formation and removal of the dye-proof layer are required repeatedly. Therefore, the manufacturing process was complicated. 2) In the printing method, the transferability of the printing ink to the glass is inferior, so that the defective shape of the colored pattern and the uneven density are likely to occur, and it is also disadvantageous in the alignment of the patterns of three or four colors. It was difficult to form a high quality filter by In the method of 3), since the density of the colored layer is determined by the thickness of the colored layer, a precise coating technique is required to keep the density of the colored layer constant. Further, after forming the first color, it is difficult to obtain a uniform coating layer in order to apply the second color layer because of the unevenness of the surface based on the first color layer. 4)
In the method of (1), when transferring the colored image to the final support, the image of each color is correctly arranged at a desired position (hereinafter, referred to as "positioning"
It was difficult to call). The method 5) is essentially excellent in that the steps of forming a colored image are simplified, exposure, development, and density control are easy, and in addition, no misalignment occurs in the transfer operation with respect to the registration of each colored image. . Further, since the colored photosensitive resin layer, which has been uniformly applied in advance with a constant thickness, is transferred, the exposure and development characteristics are stable, and the density control of the final colored image obtained is easy.

However, if small dust or foreign matter is inserted between the transparent glass substrate and the colored photosensitive resin layer during transfer,
At the time of development, the colored photosensitive resin layer in that portion is peeled off, resulting in a color filter with missing pixels (referred to as white voids). This is a phenomenon rarely seen in the production of a color filter by applying a colored resist solution. In order to form a color filter, red, green, blue, and black are required to be processed four times. Therefore, the first colored image is four times, the second colored image is three times,
The third colored image is developed twice and plural times. When very small dust is sandwiched between the transparent glass substrate and the colored photosensitive resin layer at the time of transfer, the photosensitive resin layer is rarely peeled off by one development, and the second, third and other colors are exposed. It often peels off during development of the functional resin layer. Even if it is a work in a clean room, dust is not generated from the laminator, the worker, the image forming material, etc., and it is difficult to obtain a high yield.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for forming a color filter by transferring an image forming material, which is capable of obtaining a color filter with few pixel defects (white defects). That is.

The object of the present invention is (1).
A step of bringing the colored photosensitive resin layer into contact with the transparent substrate of the image-forming material provided on the temporary support while heating the transparent substrate, (2) a step of peeling the temporary support, (3) A step of pattern-exposing the photosensitive resin layer, (4) a step of developing the photosensitive resin layer, (5) a step of curing the photosensitive resin layer on a substrate provided with the patterned photosensitive resin layer A step of irradiating light including a wavelength range, (6) above (1) to
(5) is repeated for image forming materials colored in different hues, and a method for producing a color filter is achieved. Hereinafter, the present invention will be described in detail.

First, an image forming material in which a colored photosensitive resin layer is provided on a temporary support will be described. As the temporary support for the colored photosensitive resin layer used in the present invention, it is necessary that it has flexibility and does not cause significant deformation, shrinkage or elongation even under pressure or under pressure and heating. .. Examples of such a support include polyethylene terephthalate film, cellulose triacetate film, polystyrene film, and polycarbonate film. Biaxially oriented polyethylene terephthalate film is particularly preferred.

On the support, a colored photosensitive resin layer is provided directly, or via an intermediate layer having ultraviolet transparency and low oxygen permeability. Further, it is preferable to provide a thermoplastic resin layer for the purpose of avoiding inclusion of 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 layer in this order.

The intermediate layer is an air which, when the colored photosensitive resin layer is adhered to the transparent substrate, the temporary support is peeled off and pattern exposure is carried out, and which interferes with the photo-curing reaction in the colored photosensitive resin layer. It is provided as a barrier layer for preventing diffusion of oxygen from the inside and for preventing the thermoplastic resin layer and the photosensitive resin layer from being mixed with each other when the three layers are laminated. Therefore, it is preferable that the colored photosensitive resin layer cannot be mechanically peeled from the photosensitive resin layer and the oxygen blocking ability is high. Such an intermediate layer is formed by applying a solution of the polymer directly on the temporary support or through the thermoplastic resin layer. Suitable polymers include polyvinyl ether / maleic anhydride polymers, water-soluble salts of carboxyalkyl cellulose, water-soluble cellulose ethers and carboxy described in JP-B-46-32714 and JP-B-56-40824. A group consisting of water-soluble salts of alkyl starch, polyvinyl alcohol, polyvinylpyrrolidone, various polyacrylamides, various water-soluble polyamides, water-soluble salts of polyacrylic acid, gelatin, ethylene oxide polymer, various starches and the like. And a water-soluble salt of styrene, a copolymer of styrene / maleic acid, a maleinate resin, and a combination of two or more of these. Particularly preferred is the combination of polyvinyl alcohol and polyvinyl pyridone. The polyvinyl alcohol preferably has a saponification rate of 80% or more, and the content of polyvinylpyrrolidone is preferably 1% by weight to 75% by weight of the solid content of the intermediate layer, and more preferably 1%.
Wt% to 60 wt%, more preferably 10 wt% to 5
It is 0% by weight. If it is less than 1% by weight, sufficient adhesion with the photosensitive resin layer cannot be obtained, and if it exceeds 75% by weight, the oxygen blocking ability is lowered. The thickness of the intermediate layer is very thin, about 0.1
It is 5 μm, particularly 0.2 to 2 μm. If it is less than 0.1 μm, the oxygen permeability is too high, and if it exceeds 5 μm, it takes too much time during development or removal of the intermediate layer.

The resin forming the thermoplastic resin layer preferably has a substantial softening point of 80 ° C. or lower. As the alkali-soluble thermoplastic resin having a softening point of 80 ° C. or lower,
Saponification product of ethylene-acrylic acid ester copolymer, saponification product of styrene and (meth) acrylic acid ester copolymer, saponification product of vinyltoluene and (meth) acrylic acid ester copolymer, poly (meth) acrylic acid It is preferable that at least one is selected from esters, saponified products of (meth) acrylic acid ester copolymers such as butyl (meth) acrylate and vinyl acetate, and the "Plastic Performance Handbook" (Japan Plastics Industry Federation, All Nippon Edited by Japan Federation of Plastic Molding Industries, published by Industrial Research Board, 1968 1
Among the organic polymers having a softening point of about 80 ° C. or less as issued on October 25), those soluble in an alkaline aqueous solution can be used. Further, even in the case of an organic polymer having a softening point of 80 ° C. or higher, various plasticizers compatible with the polymer are added to the organic polymer to obtain a substantial softening point of 80.
It is also possible to lower it to below ℃. In addition, in order to adjust the adhesive force with the temporary support in these organic polymer substances,
It is possible to add various polymers, supercooling substances, adhesion improvers or surfactants, release agents, etc. within a range where the substantial softening point does not exceed 80 ° C. Specific examples of preferable 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 preferably 6 μm or more. The reason for this is that the thickness of the thermoplastic resin layer is 5 μm.
This is because if the thickness is less than 1 μm, it is not possible to completely absorb the unevenness of the base, and bubbles are easily generated between the base and the base during transfer. The upper limit is 100 μm or less, preferably 50 μm or less, from the viewpoint of developability and production suitability.

The photosensitive resin layer preferably becomes soft or tacky at a temperature of at least 150 ° C. or less, and is preferably thermoplastic. Most of the layers using known photopolymerizable compositions have this property, but some of the known layers can be further modified by the addition of thermoplastic binders or compatible plasticizers. . The material for the photosensitive resin layer of the present invention is known, for example, JP-A-3-28.
All of the photosensitive resins described in 2404 can be used. Specific examples include a photosensitive resin layer composed of a negative type diazo resin and a binder, a photopolymerizable composition, a photosensitive resin composition composed of an azide compound and a binder, and a cinnamic acid type photosensitive resin composition. Of these, photopolymerizable resins are particularly preferable. The photopolymerizable resin is a photopolymerization initiator,
It contains a photopolymerizable monomer and a binder as basic components.

As the photosensitive resin, there are known one which can be developed with an alkaline aqueous solution and one which can be developed with an organic solvent. From the viewpoints of preventing pollution and ensuring labor safety, an alkaline aqueous solution developable resin. Is preferred.

To the photosensitive resin layer, pigments of red, green, blue and black, which are the constituent colors of the color filter, are further added. Preferred examples of these are Carmine 6B.
(C.I. 12490), phthalocyanine green (C.I. 74260), phthalocyanine blue (C.I.
I. 74160), carbon black and the like. The content of the pigment in the colored photosensitive resin is 1
It is preferably ˜30 wt%. More preferably 5
Is about 20% by weight.

The image-forming material used in the present invention is obtained by applying a colored photosensitive resin solution onto a temporary support and drying it. Further, if necessary, a thermoplastic resin layer and an intermediate layer are provided. In that case, first, a thermoplastic resin layer solution is applied and dried to form a thermoplastic resin layer, and then the thermoplastic resin layer is provided. A solution of an intermediate layer material made of a solvent that does not dissolve the thermoplastic resin layer is applied onto the layer, dried, and then a photosensitive resin layer is applied and dried with a solvent that does not dissolve the intermediate layer. Next, a method of manufacturing a color filter using the image forming material prepared by the above method will be described.

When a color filter is manufactured using the image forming material of the present invention, two processes can be selected depending on the method of forming the black matrix light shielding layer.
One of them is a method of forming a black matrix light-shielding layer with a metal thin film, and the other is a method of providing it by transferring an image forming material similarly to each pixel of red, green and blue. When a metal thin film is used, it is preferable to form a black matrix light-shielding layer by a metal thin film before forming each pixel of red, green, and blue. On the other hand, when a black matrix light-shielding layer is formed by transferring an image forming material, ,red,
It is preferable to provide after forming each of the green and blue pixels. The black matrix light-shielding layer formed of a metal thin film is obtained by forming Cr of 100 to 300 nm on a glass substrate having a thickness of about 1 mm by a method such as sputtering or vacuum deposition, and patterning it in a matrix by photolithography. As the metal thin film, various materials other than Cr can be used, but Cr is preferable because the film is black, the adhesion to the glass substrate, the film denseness, and the light blocking ability. First, a photosensitive resin layer of an image forming material is attached to a transparent glass substrate (or a Cr black matrix light shielding layer forming substrate) having a thickness of about 1 mm under pressure and heating. In this case, it is preferable to undercoat the transparent glass substrate in advance with an undercoat such as a silane coupling agent because the adhesion between the photosensitive resin layer and the transparent glass substrate is improved.
A conventionally known laminator or a vacuum laminator can be used for bonding, and an auto-cut laminator can also be used for higher productivity. After that, the temporary support is peeled off, and then exposed and developed through a predetermined photomask, a thermoplastic resin layer, and an intermediate layer. here,
It is preferable to peel off the thermoplastic resin layer together with the temporary support in order to obtain high resolution and shorten the development time. This can be achieved by controlling the adhesion balance between the temporary support, the thermoplastic resin layer, the intermediate layer, and the photosensitive resin layer. It is also possible to expose before the temporary support is peeled off, and then peel off the temporary support for development, but in order to obtain high resolution, it is preferable to peel before the exposure.

The development is carried out by a known method by immersing in a solvent or an aqueous developer, especially an alkaline aqueous solution, or applying a developer spray from a spray, rubbing with a brush, or irradiating with ultrasonic waves. It is done by that.

Next, the substrate after the development treatment is irradiated with light having a wavelength range capable of curing the colored photosensitive resin layer, that is, 365 nm and 405 nm. Irradiation (hereinafter referred to as post-exposure) may be performed from the color filter formation surface, the opposite surface, or both sides. Since the formed pixels themselves absorb these lights, it is more effective to irradiate from the opposite side of the color filter forming surface, and it is still more effective to irradiate from both sides. Irradiation amount is 5 mj or more on one side, preferably 50 m
It is at least j, more preferably at least 200 mj, and there is no particular upper limit, but in view of manufacturing suitability, it is approximately 3000 mj. When the irradiation amount is less than 5 mj, the effect of preventing white spots is small, and when it exceeds 3000 mj, problems occur such as enlargement of the apparatus and a long processing time. As the irradiation method, known techniques such as a method of collectively exposing light from an ultra-high pressure mercury lamp one by one, a method of irradiating light from above or below while conveying a pixel formation substrate by a conveyor, or both of them are used. Available. A color filter can be formed by repeating the steps from bonding the image forming material to post exposure for red, green, blue and black. Naturally, the black image forming step can be omitted when the glass substrate on which the black matrix light-shielding layer is previously formed by the metal thin film is used.

If a small dust is sandwiched between the transparent glass substrate and the colored photosensitive resin layer, but white spots are not obtained in one development process, post-exposure is carried out by performing post exposure. It is possible to prevent film peeling, that is, white spots, from occurring in another portion of the resin layer when the resin layer is hardened and the other color is developed thereafter. Even if the exposure amount at the time of pattern exposure is increased, the white spots can be reduced, but in this case, the image becomes unnecessarily thick due to the wraparound of light, so this method cannot be adopted.

Next, other effects of the present invention will be described. As described above, when the development processing is performed a plurality of times, over-development occurs, the peripheral portion of the pixel is eluted, and the shape of the pixel (called side etching) is destroyed. In particular, in the case of a green photosensitive resin, the coloring material strongly absorbs ultraviolet rays for pattern exposure, so that it becomes difficult to sufficiently cure the inside,
When the development processing is performed a plurality of times, the film thickness at the peripheral portion of the pixel becomes thin due to side etching. The same can be said for the photosensitive resin layers of other colors, although there are some differences. Therefore, post-exposure is performed after the development processing of the photosensitive resin layers of the respective colors, and particularly after the development processing of the green photosensitive resin layer, it is possible to prevent an increase in side etching. The appropriate exposure amount in this case is also as described above.

In the color filter formation by the transfer method, the black pixel is generally formed last,
Basically, the pixels are not developed after that,
Therefore, from the viewpoint of preventing white spots and side etching, post-exposure is not necessary after the last black pixel formation, but the black photosensitive resin layer has a lower UV transmittance than the green photosensitive resin layer, and even after the development process. It is in a semi-cured state. It is preferable to carry out post-exposure even after the last black pixel formation for the purpose of sufficiently curing this. When the black matrix is formed of the metal thin film, black pixels are not formed, and post-exposure after the final pixel formation is unnecessary.

Further, if necessary, a protective layer for the purpose of physical and chemical protection and flattening of the surface of the color filter may be laminated on the color filter. As the protective layer, an acrylic, urethane, or silicone resin film or a highly transparent film such as a metal oxide such as silicon oxide is used. The resin film is formed by spin coating. In addition to the roll coating, the printing method, and the like, it can be formed by transfer like the above-mentioned image forming material. The inorganic film such as a metal oxide can be provided by a sputtering method, a vacuum vapor deposition method, or the like.

[0024]

【Example】

Example 1 A 75 μm thick polyethylene terephthalate film temporary support was coated with a coating solution having the following formulation H1 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 (copolymerization composition ratio (molar ratio) = 55 / 28.8 / 11.7 / 4.5 , 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 Part Methyl ethyl ketone 30 parts by weight

Next, the following formulation B1 was formed on the thermoplastic resin layer.
The coating liquid consisting of is applied and dried to give a dry film thickness of 1.6μ.
An m-thick intermediate layer was provided.

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

On the temporary support having the above-mentioned thermoplastic resin layer and intermediate layer, the red (R
Layer), green (for layer G), blue (for layer B) and black (B)
A four-color photosensitive solution (for L layer) was applied and dried to form a colored photosensitive resin layer having a dry film thickness of 2 μm.

Table 1: Composition of coating liquid for colored photosensitive layer Red Green Blue Black (g) (g) (g) (g) ―――――――――――――――――――― ―――――――――――――――― Benzyl methacrylate / methacrylic acid copolymer 60 60 60 60 (Molar ratio = 73/27, viscosity = 0.12) Pentaerythritol tetraacreyl 43.2 43.2 43.2 43.2 Michler's Ketone 2.4 2.4 2.4 2.4 2- (o-Chlorophenyl) -4,5-2.5 2.5 2.5 2.5 Diphenylimidazole dimer Irgazine Red BPT (red) 5.4 --- Sudan Blue (blue) -5.2 --- Copper Phthalocyanine (green) ) − − 5.6 − Carbon black (black) − − − 5.6 Methyl cellosolve acetate 560 560 560 560 Methyl ethyl ketone 280 280 280 280 280 ―――――――――――――――――――――――― ――――――― ----

Further, a polypropylene (12 μm thick) covering sheet was pressure-bonded onto the photosensitive resin layer to prepare red, blue, green and black image forming material materials. Using this image forming material, a color filter was prepared by the following method. A transparent glass substrate (Corning # 7059) having a thickness of 1.1 mm and 400 mm × 300 mm was washed, immersed in a 1% aqueous solution of a silane coupling agent (Shin-Etsu Chemical KBM-603) for 3 minutes, and then washed with pure water for 30 seconds. Excess silane coupling agent was washed off, 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 transparent resin substrate surface was treated with a silane coupling agent. A transparent glass substrate was pressed with a laminator (Auto Cut Laminator ASL-24 manufactured by Somar Co., Ltd.) (10 kg / cm). Then, they were heated and bonded to each other, and subsequently, peeled at the interface between the temporary support and the thermoplastic resin layer to remove the temporary support. Next, after exposing through a predetermined photomask, developing, and removing unnecessary portions, an ultraviolet ray of 300 is emitted from the opposite side of the color filter forming surface using an ultra-high pressure mercury lamp.
Irradiation with mj was performed to form a red pixel pattern on the transparent glass substrate. Subsequently, a green image forming material was laminated on the glass substrate on which the red pixel pattern was formed in the same manner as above, and peeled, exposed, developed and post-exposed to form a green pixel pattern. The same process was repeated for blue and black image forming materials to form a color filter on a transparent glass substrate. After forming the black pixels, post exposure was performed with the same light amount from the color filter forming surface and the opposite surface. The conditions of transfer, exposure, development, and post exposure are as shown in Table 2.

Table 2: Transfer, exposure, development and post exposure conditions ――――――――――――――――――――――――――――――――――― ― Transfer Transfer speed Exposure 1 Development 2 Development 2 Post exposure Color temperature (℃) (m / min) (mj) (sec) (sec) (mj) ―――――――――――――――― ――――――――――――――――― Red 130 0.2 20 70 70 50 300 Green 140 0.2 20 20 70 25 300 Blue 150 0.2 0.2 20 70 60 300 300 Black 130 0.2 300 70 25 1000 (front and back) ――――――――――――――――――――――――――――――――――――

Other conditions and supplementary explanation of Table 2 are as follows. 1. Development 1 is development for dissolving and removing the thermoplastic resin layer and the intermediate layer, and triethanolamine 1% is used as a developing solution.
Shower development was performed at 33 ° C. using an aqueous solution. 2. In Development 2, the colored photosensitive resin layer was developed, and shower development was performed at 33 ° C. using a 1% aqueous solution of Color Mosaic Developer CD-1000 (manufactured by Fuji Hunt Electronics Technology Co., Ltd.) as a developer. The color filter formed under the above conditions has no pixel omission (white omission), and the side etch of each pixel is small.
It had sufficient performance as a color filter.

Comparative Example 1 A color filter was formed under exactly the same conditions as in Example except that post exposure was not performed. As a result, white spots occurred in each color pixel, and it was impossible to use it as a color filter.

[0034]

According to the present invention, the colored photosensitive resin layer provided on the temporary support is transferred to a transparent glass substrate, the temporary support is peeled off, pattern exposure and development are performed, and then the colored photosensitive resin layer is formed. The step of irradiating light containing a wavelength range that can cure
By repeating the processes for image forming materials colored in different hues, it is possible to manufacture an excellent color filter having a good pattern shape with no pixel omission (white omission) and less side etching of the pixel.

Claims (1)

[Claims] 1. A step of (1) bringing a colored photosensitive resin layer into a temporary support to bring the photosensitive resin layer into close contact with the transparent substrate while heating the image forming material, (2) the temporary support. A step of peeling the body, (3) a step of pattern-exposing the photosensitive resin layer, (4) a step of developing the photosensitive resin layer, (5)
A step of irradiating a substrate provided with the patterned photosensitive resin layer with light including a wavelength range capable of curing the photosensitive resin layer, (6) coloring the above (1) to (5) in different hues And a step of repeating the above described image forming material.