JP3128161B2 - Manufacturing method of color filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter used for a color liquid crystal display device and the like, and more particularly to a color filter having a high adhesion strength of a protective film.

[0002]

2. Description of the Related Art In a liquid crystal display device, a transparent substrate such as glass provided with a transparent electrode is provided with a gap of about 1 to 10 .mu.m, a liquid crystal substance is sealed between the gaps, and a liquid crystal is fixed by a voltage applied between the electrodes. An image is displayed by a transparent portion and an opaque portion formed by orienting in the direction. The color liquid crystal display device has three color filters of red (R), green (G), and blue (B) corresponding to the three primary colors of light on any one of the transparent electrode substrates. A desired color is displayed by adding the primary colors.

A color filter for a color liquid crystal display device is formed by laminating a transparent substrate, a colored layer, a protective film, and a transparent conductive film in this order, and comprises a transparent substrate formed with electrodes or thin film transistors opposed to the three primary colors of RGB. A liquid crystal display device is formed by enclosing a liquid crystal material while maintaining an interval of 1 to 10 μm.

[0004]

As shown in the sectional view of FIG. 4, a color filter is formed on a transparent substrate such as a glass substrate 41 by R, G, B by a pigment dispersion method, a dyeing method, an electrodeposition method, a printing method or the like. A colored layer 42 having a predetermined shape of the three primary colors is formed, and a protective film 43 is formed on the colored layer for the purpose of protecting the colored layer.
Is formed, and a transparent electrode 44 for driving liquid crystal is formed on the protective film.

There are two types of color liquid crystal display devices, a simple matrix type and an active matrix type, depending on the driving method of the liquid crystal. Recently, a display device such as a personal computer has an excellent image quality, and each pixel must be controlled reliably. And an active matrix system having a high operation speed is being adopted.

In an active matrix type liquid crystal display device, a thin film transistor (TFT) element is formed for each pixel on a glass substrate, and the switching action of each element controls the liquid crystal shutter action of each pixel. A uniform transparent electrode is formed at a counter electrode of these elements.

For the transparent electrode, a composite oxide of tin oxide, indium oxide and ITO is used. There are various methods for forming a transparent electrode, such as vapor deposition, ion plating, and sputtering. However, since the protective film serving as the base of the transparent electrode of the color filter is formed of a synthetic resin, the heat resistance of the protective film is high. In view of the above, there is a demand for a method capable of forming a film at a relatively low temperature. For this reason, sputtering is widely used in the production of transparent electrodes for color filters.

The stress generated in the transparent conductive film formed by sputtering on the protective film increases as the thickness increases. However, when a transparent conductive film having a low electric resistance and a large thickness is formed, the adhesion between the protective film and the colored layer is increased. If the property is low, wrinkles or cracks occur in the protective film or the transparent electrode film, which adversely affects the quality of the liquid crystal display device. Therefore, it is required to increase the adhesion between the protective film and the colored layer. . Therefore, in order to enhance the adhesion between the colored layer and the protective film, it was found that a layer composed of a silane coupling agent was formed between the colored layer and the protective film. After the silane coupling agent is dried after forming a uniform coating with a spinner or the like and dropped to form a coating layer of the silane coupling agent, the silane coupling agent is formed before the next protective film forming step. The activity of the agent may decrease.

[0009]

Means for Solving the Problems The present inventors have studied means for solving the above-mentioned problems, and as a result, in order to enhance the adhesion between the colored layer and the protective film, a solution of a silane coupling agent was applied to the colored layer. After the silane coupling agent is dried, the coating layer of the silane coupling agent is irradiated with ultraviolet rays in an atmosphere containing water vapor and oxygen to stabilize the activity of the silane coupling agent. By doing so, it has been found that a color filter having excellent protective film adhesion can be obtained.

Various resins can be used as the protective film in the color filter of the present invention. However, if a photosensitive resin is used, it is easy to form the protective film at a desired portion of the color filter. It is preferable to use a curable resin. As the ultraviolet curable resin, a resin composed of a photopolymerizable acrylate oligomer and a polyfunctional photopolymerizable acrylate monomer can be used. The photopolymerizable acrylate oligomer has a molecular weight of 1,000.
About 2000, and a molecular weight of 1000-2.
About 000 are preferable, and examples thereof include polyester acrylate, epoxy acrylate such as phenol novolak epoxy acrylate, o-cresol novolak epoxy acrylate, and polyurethane acrylate, polyether acrylate, oligomer acrylate, alkyd acrylate, polyol acrylate, melamine acrylate, and the like. And polyfunctional photopolymerizable acrylate monomers include 1,4 butanediol diacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate,
Examples include pentaerythritol triacrylate, trimethylolpropane triacrylate, pentaerythritol acrylate, dipentaerythritol hexaacrylate, and the like.

Furthermore, compared to the photopolymerizable resin obtained by adding a polyfunctional photopolymerizable acrylate monomer to the above photopolymerizable acrylate oligomer, the mixture of the photopolymerizable acrylate oligomer and the epoxy resin has one molecule per molecule. By using a photosensitive acrylic resin to which a polyfunctional photopolymerizable acrylate monomer having multiple functional groups is added, it is possible to increase the degree of crosslinking of the resin to obtain a rigid and high-hardness film, and a thick transparent film on the protective film Even if an electrode is formed, not only cracks and wrinkles do not occur, but also a difference in height occurs between a concave portion formed between adjacent R, G, B of the colored layer and a portion of R, G, B, A protective film having good flatness with very few irregularities on the surface of the protective film can be obtained.

The photopolymerizable acrylate oligomer usable for this purpose includes a molecular weight of 1,000 to 200.
0 is preferable, polyester acrylate or phenol novolak epoxy acrylate, o
-Epoxy acrylates such as cresol novolak epoxy acrylate or polyurethane acrylate, polyether acrylate, oligomer acrylate, alkyd acrylate, polyol acrylate,
Melamine acrylate and the like can be mentioned. Examples of the epoxy resin include a phenol novolak type epoxy resin and a cresol novolak type epoxy resin having the following chemical structural formula.

[0013]

Embedded image

The polyfunctional photopolymerizable acrylate monomers include 1,4 butanediol diacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate,
Pentaerythritol acrylate, dipentaerythritol hexaacrylate and the like can be mentioned.

The protective film is formed by adding a polymerization initiator and an epoxy curing agent to a photopolymerizable acrylate oligomer, a phenol novolak type epoxy resin, and a polyfunctional photopolymerizable acrylate monomer on a colored layer provided on a transparent substrate. Spinner method, roll method, spray method,
After applying by a coating method such as a screen printing method, a mask on which a pattern of a predetermined electrical connection portion is drawn is placed, and ultraviolet light is applied to cure a necessary portion, and a portion where the ultraviolet light is not applied By dissolving and removing the uncured photosensitive resin with a solvent, it is possible to form a rigid and high-hardness resin protective film having a high degree of crosslinking only in a predetermined region.

Next, a solution of a silane coupling agent is applied on the protective film to form a layer of the silane coupling agent. As the silane coupling agent, KBP-40 and KBP-41 manufactured by Shin-Etsu Silicone Co., Ltd. , KBP-43,
KBM-603, KBE-903 (both trade names),
An amino-based, epoxy-based, acrylic-based, or vinyl-based silane coupling agent such as DuPont's VM-651 (trade name) can be used. The amount of the silane coupling agent applied is 0.01% to 0.5% of a solution of 1 m ^2.
The amount of the silane coupling agent is preferably from 500 to 200 g / min by a spinner after dropping the silane coupling agent.
A uniform coating layer can be formed at 0 revolutions / minute.

Irradiation of ultraviolet rays is performed by using 184.9 nm, which is a wavelength at which oxygen is excited to generate ozone, and synthetic quartz, which generates a large amount of 253.7 nm ultraviolet rays, which decompose this ozone and generate oxygen radicals, in the tube. It is preferable to use the low-pressure mercury lamp used for the material. The distance between the low-pressure mercury lamp and the surface of the color filter to be treated is preferably 20 mm to 50 mm. If the output of the low-pressure mercury lamp is too large, it will adversely affect the colored layer made of an organic substance.
About 00W to 500W is appropriate. The irradiation time of the ultraviolet rays is set to 5 to 10 seconds, preferably at most 5 minutes. If the irradiation time is long, the colored layer may be deteriorated. In addition, the irradiation of ultraviolet rays improves the efficiency by installing a low-pressure mercury lamp in a production line where the substrate of the color filter is transported by a transport means such as a belt conveyor from the step of applying the silane coupling agent to the step of forming the protective film. The composition of the protective film can be applied in a state where the activity of the surface of the silane coupling agent is sufficiently maintained.

The atmosphere in the apparatus for irradiating ultraviolet rays must contain oxygen, but may be air. Further, by increasing the humidity of the atmosphere to 60 to 90% RH, deterioration of the colored layer can be prevented. However, if the humidity is too high, a water film is formed on the surface of the coating layer of the silane coupling agent.

[0019]

After forming a coating layer of a silane coupling agent on a colored layer formed on a color filter, the surface of the silane coupling agent is irradiated with ultraviolet rays, ozone and oxygen radicals in an atmosphere containing oxygen and water vapor. After the activity of the protective film is increased, the composition of the protective film is applied and cured to improve the adhesion between the colored layer and the protective film. As a result, the ITO formed on the protective film is formed.
A transparent electrode made of a film can also have good characteristics. Hereinafter, examples of the present invention will be shown and described in more detail.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A color filter according to the present invention will be described with reference to the drawings. FIG. 1 is a partial sectional view of the color filter of the present invention. In the color filter 1, a black matrix 3 made of metal chromium or the like is formed on a glass substrate 2, and R
Colored layer 4 composed of three primary colors (red), G (green), and B (blue)
Are formed, and after the colored layer is formed, the silane coupling agent layer 5 is formed on the colored layer. Then, on the silane coupling agent layer 5, a protective film 6 made of a transparent synthetic resin for protecting the coloring layer is formed. An ITO film 7 is provided on the protective film.

FIG. 2 shows an example of an activating device used for activating the applied silane coupling agent layer. A low-pressure mercury lamp 23 is attached to the section. UV protection cover 2 before and after the UV irradiator
4 is attached, and the color filter substrate 25 to be treated with ultraviolet rays and ozone is sent to the irradiation unit by the transport device 26, and the ultraviolet rays and the oxygen in the atmosphere are excited by the ultraviolet rays, and the generated ozone is further decomposed. The coating layer 27 of the silane coupling agent is activated by the generated oxygen radicals. Also, the exhaust port 2 of the activation device
An ozone decomposing device 29 is connected to 8 to completely decompose ozone in exhaust gas and discharge it to the outside.

As the composition of the protective film, many compositions can be used, and a photosensitive resin obtained by adding a polyfunctional photopolymerizable acrylate monomer to a photopolymerizable acrylate oligomer has excellent properties after curing. It is preferred.

Examples of the photopolymerizable acrylate oligomer include polyester acrylate, epoxy acrylate such as phenol novolak epoxy acrylate, o-cresol novolak epoxy acrylate, polyurethane acrylate, polyether acrylate, oligomer acrylate, alkyd acrylate, polyol acrylate, and melamine acrylate. Examples of the polyfunctional photopolymerizable acrylate monomer include 1,4 butanediol diacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, and pentane. Erythritol acrylate, dipentaerythritol Le hexaacrylate, and the like. Further, benzophenone or Irgacure 184, Irgacure 907, Irgacir 651 (all trade names of Ciba-Geigy), Darocure (trade name of Merck), etc. are added to the photopolymerizable resin as an initiator at a solid content ratio of about 1 to 3%. May be.

Particularly preferred compounding ratio (weight%) of the photopolymerizable acrylate oligomer and the polyfunctional photopolymerizable monomer is as follows: Formulation Example 1 Phenol novolak epoxy acrylate: 60% Trimethylolpropane triacrylate: 17% Dipentaerythritol hexaacrylate 20% Irgacure 184 3% Formulation 2 O-cresol novolac epoxy acrylate 60% Dipentaerythritol hexaacrylate 38% Irgacure 184 2% Formulation 3 Polyurethane acrylate 50% Dipentaerythritol hexaacrylate 48 % Irgacure 651 2% Formulation Example 4 Melamine acrylate 70% Trimethylolpropane triacrylate 27% Irgacure 184 3% Can be.

Further, the compounding ratio (% by weight) of the composition containing the photopolymerizable acrylate oligomer and the polyfunctional photopolymerizable monomer to the epoxy resin is as follows: Compounding ratio: 5 Phenol novolak epoxy acrylate: 40% Phenol novolak type epoxy resin ... 18% trimethylolpropane triacrylate ... 17% dipentaerythritol hexaacrylate ... 20% Irgacure 184 ... 3% UVE1014 (manufactured by GE) ... 2% Compounding ratio 6 o-cresol novolak epoxy acrylate ... 40% cresol novolac epoxy Resin: 18% Dipentaerythritol hexaacrylate: 38% Irgacure 184: 2% UVE1014 (manufactured by GE): 2% Compounding ratio: 7 Polyurethane acrylate: 35% Phenol novolak Type epoxy resin ... 13% Dipentaerythritol hexaacrylate ... 48% UVE1014 (manufactured by GE) ... 2% Irgacure 651 ... 2% Compounding ratio 8 Melamine acrylate ... 49% Phenol novolak type epoxy resin ... 20% Trimethylolpropane triacrylate ... 27% UVE1014 (manufactured by GE) ... 2% Irgacure 184 ... 2%.

Example 1 Red, green, and blue pigments are dispersed in a photosensitive resin in the composition ratios shown below, respectively, to produce red, green, and blue colored photosensitive resins. (1) Red photosensitive resin Pyrazolone red (red pigment) ... 10 Polyvinyl alcohol / 5% stilbazolium quinolium (Photosensitive resin) ... 5 Water ... 85 (2) Green photosensitive resin Lionol Green 2Y-301 (Green) Pigment) ... 9 Polyvinyl alcohol / 5% stilbazolium quinolium (photosensitive resin) ... 5 Water ... 86 (3) Blue photosensitive resin fast dogen blue (blue pigment) ... 3 Polyvinyl alcohol / 5% stilbazolium quinolium Lithium (photosensitive resin) 5 Water 92 The substrate is a 1.1 mm thick glass substrate (Asahi Glass Co., Ltd.)
AL material) was sufficiently washed and used, and a black matrix of metal chromium having a thickness of 100 nm, an aperture ratio of 50%, and the size of each pixel of 20 μm × 40 μm was formed on the glass substrate by sputtering.

On top of this, a red photosensitive resin was applied to a thickness of 1.2 μm, dried in an oven at a temperature of 70 ° C. for 30 minutes, exposed with a mercury lamp, and exposed to water. Spray development is performed for 1 minute to form a red relief image in a region where a red pixel is to be formed.
For 30 minutes.

By repeating the same process, a green relief pixel was formed in a region where a green pixel was to be formed, and a blue relief pixel was formed in a region where a blue pixel was to be formed, thereby forming a colored layer.

Next, 5% by weight of KBP-41 (trade name) manufactured by Shin-Etsu Silicone Co., Ltd. was used as a silane coupling agent.
A butyl acetate solution was applied to a coating amount of 10 mg / m ² and then dried to remove the solvent to form a coating film of a silane coupling agent. Subsequently, the substrate on which the coating layer of the silane coupling agent was formed was passed through the activation device shown in FIG. 2 at a speed at which the irradiation time of the ultraviolet light became 5 seconds. At this time, the atmosphere in the activation device was air, and the humidity was set to 80% RH. Thereafter, 50 parts by weight of o-cresol novolak epoxy acrylate (molecular weight 1500 to 2000) as a photocurable acrylate oligomer and dipentaerythritol hexaacrylate (DPHA manufactured by Nippon Kayaku Co., Ltd.) as a polyfunctional polymerizable monomer.
Was mixed with 200 parts by weight of ethylcellosolve acetate, and a mixture obtained by mixing 2 parts by weight of Irgacure (manufactured by Ciba Geigy) as a polymerization initiator was dissolved in the mixture. It was applied to a thickness of 2.0 μm on the colored layer.

Ultraviolet rays were irradiated for 10 seconds by a 2.0 kW ultra-high pressure mercury lamp using a proximity aligner on which a predetermined photomask was arranged. Subsequently, the film was immersed in a developer consisting of 1,1,2,2-tetrachloroethane at a temperature of 25 ° C. for 1 minute to remove only the uncured portion of the coating film.

Next, the adhesion strength of the protective film on the substrate on which the protective film was formed was measured by the method shown in FIG. (A) and (D) show plan views, and (B), (C) and (E)
Shows a sectional view. First, the film 31 made of polyethylene terephthalate having a thickness of 12 μm is 0.5 mm long and 5 mm wide.
(A) was attached to a glass surface 33 having the same size as the glass substrate used for the filter so that the center of the opening was 5 mm from the end. Next, as an epoxy resin, Aral Ditrapid (trade name) manufactured by Ciba Geigy Co., Ltd. is applied to the opening, and a coating film 35 having a uniform thickness corresponding to the thickness of the polyethylene terephthalate film is applied to the opening by a squeegee 34 for screen printing.
(B), the polyethylene terephthalate film is removed, the epoxy resin is pre-baked, and then the color filter 37 on which the protective film 36 to be measured for the adhesion is formed is overlapped so that the overlapping portion of both becomes 10 mm. The adhesive surface was fixed with a clip (C). Next, the area of the adhesive portion 38 is increased as a result of the area of the epoxy resin application portion being compressed, so the adhesive portion was photographed with a stereoscopic microscope, and the area of the adhesive portion was measured by an area measuring machine (D). Next, the color filter 37 to be measured was joined to the reinforcing glass 39, and the end portion 40 of the color filter was pulled until the joint was broken, and the strength at the time of breaking was recorded (E). As a result, the strength of the broken portion was 20 to 22 kg / m ² . Further, no difference was observed in the adhesion strength between the chromium layer and the colored layer.

Comparative Example 1 After forming a coating layer of a silane coupling agent on a colored layer, a protective film was formed in the same manner as in Example 1 except that ultraviolet light was not irradiated by an activating device. was measured the adhesion strength of the protective film in the same manner as in example 1, the colored layer 6~16kg / m ² and vary widely, the adhesion and 6 kg / m ² is on the chromium layer is lowered.

[0033]

According to the present invention, a layer of a silane coupling agent is formed on a colored layer of a color filter, and then irradiated with ultraviolet rays in an atmosphere containing water vapor and oxygen, and then a composition for a protective film is applied. The cured film has good adhesion between the colored layer and the protective film, and when a transparent conductive film made of an ITO film is formed on the protective film, the transparent conductive film has excellent quality without cracks and wrinkles. Transparent conductive film can be formed.

[Brief description of the drawings]

FIG. 1 shows a cross-sectional view of a part of a color filter manufactured by a method of the present invention.

FIG. 2 is a view illustrating a process of manufacturing a color filter according to the method of the present invention.

FIG. 3 is a diagram showing a method for measuring adhesion strength.

FIG. 4 is a diagram illustrating an example of a conventional color filter.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Color filter, 2 ... Glass substrate, 3 ... Black matrix, 4 ... Coloring layer, 5 ... Silane coupling agent layer, 6 ... Protective film, 7 ... ITO film, 21 ... Activator, 2
2 ... UV irradiation part, 23 ... Low pressure mercury lamp, 24 ... UV leakage prevention cover, 25 ... Color filter substrate, 26 ... Conveying device, 27 ... Coating layer of silane coupling agent, 28 ...
Exhaust port, 29: Ozone decomposer, 31: Film, 32
... opening, 33 ... glass surface, 34 ... squeegee, 35 ... coating film, 36 ... protective film, 37 ... color filter, 38 ...
Adhesive part, 39: reinforcing glass, 40: end of color filter, 41: glass substrate, 42: colored layer, 43: protective film, 44: transparent electrode

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02B 5/20 101 G02F 1/1335 505

Claims (1)

(57) [Claims] 1. After applying a silane coupling agent on a colored layer formed on a transparent substrate, the oxygen-containing
A method for producing a color filter, comprising irradiating an ultraviolet ray in an atmosphere of 0 to 80% RH, applying a protective film composition containing a polyfunctional photopolymerizable acrylate monomer, and curing the protective film.