JP2678684B2 - Photopolymerizable resin composition for color filter - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resin composition for a color filter,
More specifically, it relates to a resin composition for producing a color filter having excellent optical properties, which is used for a liquid crystal display device, a color separation device, a sensor and the like.

Conventional technology For VTR cameras, color-identifying robots, color copiers, and other color solid-state imaging devices that are in great demand, and for color liquid crystal display devices that are undergoing conversion from the CRT system due to the trend of weight reduction and thinning. The color filter used is formed by providing fine areas colored in two or more kinds of hues on a solid-state image sensor or a transparent substrate. Such a colored thin film has been conventionally manufactured by a dyeing method, a printing method, or the like, and when a high-definition image is required, the dyeing method is mainly used.

However, a color filter according to the dyeing method is usually formed on a substrate in advance with a natural photosensitive resin such as gelatin, an amine-modified polyvinyl alcohol or the like, an amine-modified acrylic resin or other dyeing base material, and then an acid dye or the like. Although it is prepared by dyeing with a dye, there is a problem that the process is very complicated and long because it is necessary to perform multi-color formation on the same substrate, and it is necessary to carry out a dye-proofing process every time the hue is changed.

In addition, since the dye used, the resin itself generally have poor light resistance, heat resistance, and moisture resistance, color filters made using these dyes naturally have problems with reliability in light resistance, heat resistance, and humidity resistance. It was

A color filter by the printing method is prepared by printing on a substrate using an ink in which a pigment is dispersed in a thermosetting resin or a photo-curing resin and then curing it by heat or light, but a high-definition image is formed. However, there was a problem in the surface smoothness of the obtained image.

In order to simplify the process, a method of internally adding a coloring material to the photosensitive resin may be considered, but in general, the photopolymerization initiator must use ultraviolet light to generate radicals. In a system in which a coloring material is internally added in advance, ultraviolet light is absorbed by the coloring material, radicals cannot be sufficiently generated, and it is difficult to form a satisfactory image. JP-A-1-152449 presents a method of obtaining an image having sufficient resolution by using a halomethyl-S-triazine compound as a photopolymerization disclosure agent in order to solve the above problems. However, in this method, when the halomethyl-S-triazine-based compound generates a radical by light, it releases a halogen element, which further pulls out a hydrogen atom in the molecule to generate hydrogen halide, which is dissociated. It had the problem of becoming ionic impurities. As described above, a photopolymerization composition for a color filter, which does not generate ionic impurities and contains a highly sensitive photopolymerization initiator, could not be obtained by the conventional technique.

(Problems to be Solved by the Invention) When a color filter is produced, a photopolymerizable compound for a color filter, which has a simple process, excellent light resistance and heat resistance, good resolution, and does not generate ionic impurities Development is desired.

(Means for Solving the Problems) As described above, the present inventors have a simple process, light resistance,
As a result of diligent efforts to find a method for producing a color filter that has excellent heat resistance, good resolution, and does not generate ionic impurities, it has been confirmed that the specific colored photopolymerizable composition satisfies the above characteristics. The present invention has been found under the heading.

That is, the present invention is a composition comprising a photosensitive resin and a pigment, wherein the photosensitive resin has a photopolymerizable compound having at least one ethylenically unsaturated double bond, a film-forming polymer binder, Provided is a photopolymerizable resin composition for a color filter, which comprises a compound represented by the formula (I).

Formula (I) The resin composition for color filters of the present invention will be described in detail.

At least one ethylenically unsaturated double bond used
The photopolymerizable compound having at least one may be a compound which can be polymerized by the action of light and has an ethylenically unsaturated double bond group. Examples thereof that can be used are photocrosslinkable or photopolymerizable monomers, oligomers, prepolymers such as ethyl acrylate, butyl acrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, ethylene glycol dimethacrylate,
Acrylic acid or methacrylic acid esters of monohydric or polyhydric alcohols such as pentaerythritol triacrylate, pentaerythritol trimethacrylate, dipentaerythritol hexaacrylate; condensation of polyhydric alcohol with monobasic acid or polybasic acid (Meth) acrylic acid obtained by reacting the obtained polyester prepolymer with (meth) acrylic acid; after reacting a compound having a polyol group and two isocyanate groups with (meth) acrylic acid Polyurethane (meth) acrylate obtained; Epoxy (meth) obtained by reacting epoxy resin with (meth) acrylic acid
Acrylate; And a polymer having a cinnamylidene group on its side chain or terminal.

Further, as the film-forming polymer, any organic polymer that is compatible with the above-mentioned photopolymerizable compound can be used. It is desirable to use these in a range of 1 to 4 times by weight with respect to the photopolymerizable compound.

Specific examples thereof include polymethacrylic acid ester or its partial hydrolyzate; polyvinyl acetate or its hydrolyzate; polystyrene; polyvinyl butyral; polychloroprene; polyvinyl chloride; chlorinated polyethylene; chlorinated polypropylene; polyvinylpyrrolidone; styrene. And a maleic anhydride copolymer or a half ester thereof; a glass transition point selected from a group of copolymerizable monomers such as acrylic acid, acrylic acid ester, methacrylic acid, methacrylic acid ester, acrylamide, and acrylonitrile. Examples thereof include a copolymer having a temperature of 35 ° C. or higher. Of these, those having an acidic group such as a carboxyl group are preferable because they are capable of aqueous development and are more economical and safe than organic solvent development.

In the resin composition of the present invention, it is preferable to use a thioxanthone compound as a photopolymerization initiator. Examples of the thioxanthone photopolymerization initiator include 2,4-diethylthioxanthone, isopropylthioxanthone, and 2-chlorothioxanthone.

The compound of the formula (I) functions as a photopolymerization initiator, and the total weight of the compound and the thioxanthone compound is
It is desirable to use in the range of 1 to 20% by weight, preferably 2 to 15% by weight of the photopolymerizable compound, and the thioxanthone compound is preferably used in 5 to 50% by weight of the total weight of the photopolymerization initiator.

The pigment to be used is required to transmit visible light, and it is desirable that the particle size of the wavelength of the transmitted light is further equal to or less than 1/2 of the wavelength,
Fine particle pigments having an average number particle size of 200 nm or less are particularly effective.

Examples of blue pigments include phthalocyanine pigments, and examples of red pigments include quinacridone pigments, perylene pigments, pyrrolo-pyrrole pigments, anthraquinone pigments, and the like.
Examples of green pigments include halogenated phthalocyanines, which may be used alone or in combination with other pigments for toning.

As the black matrix pigment, carbon, titanium carbon, iron oxide, azo black pigment, etc. may be used alone or in combination of two or more kinds.

These red, green, blue and black fine particle pigments are 10 to 60% by weight, preferably 20 to 50% by weight, based on the photosensitive resin.
It is desirable to use within the range.

The photopolymerizable resin composition of the present invention is prepared by mixing the above-mentioned respective components while treating them in a mixer or a disperser according to the amounts used, if necessary. If necessary, the mixture may be subjected to natural filtration or pressure filtration using a filter material of 0.5 μ or less.

A color filter using the resin composition of the present invention is manufactured, for example, as follows.

To the resin composition of the present invention, a thioxanthone compound and other photopolymerization initiator are added, and a solvent such as ethyl cellosolve is further added and filtered, and then the coating solution is applied to the substrate by the above spinner or the like, and the solvent is added. A coating film is obtained by drying. Next, in order to prevent contact between the coating film and oxygen that prevents photopolymerization, a resin such as PVA is coated on the coating film and dried.

The coating film thus obtained is irradiated with ultraviolet rays through a negative mask to form a desired image. At this time, a device such as a mask alignment is used so that the parallel rays are uniformly irradiated on all the coating films. Next, this light-irradiated coating film is exposed to running water of an alkaline aqueous solution or a shower to dissolve the uncured portion and develop it, whereby a color filter having a desired image is obtained.

〔Example〕

 Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1 A photosensitive resin composition having the following composition was prepared.

・ ARCO CHEMICAL SMA-2625 30gr (styrene maleic acid copolymer half ester) ・ Cypentaerythritol hexaacryl 15gr ・ 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone 1gr ・2,4-Diethylthioxanth 0.5gr-Ethyl cellosolve acetate 100gr Red, green, blue added to each of the above photosensitive resin compositions.
A black pigment paste was prepared as follows.

4 parts of a sorbitan fatty acid ester compound as a dispersant was added to 20 parts of each color pigment composition, and 76 parts of ethyl cellosolve acetate was further added, followed by dispersion with a sand mill.

The average number distribution of the red, green, and blue pigment particles dispersed here was 200 nm or less. This pigment paste was added to the photosensitive resin composition in an amount of 40% by weight, further treated with a sand mill, and then passed through a 1 μ filter with a pressure filter to obtain the photopolymerizable resin composition for a color filter of the present invention. It was

Application Example 1 The photopolymerizable resin composition obtained in Example 1 was applied by a spin coater to a smooth glass plate washed with water, alcohol and chlorofluorocarbon, and dried at 100 ° C. for 5 minutes. A 10% polyvinyl alcohol aqueous solution was applied onto the obtained coating film by a spin coater, and dried at 100 ° C. for 5 minutes. The coating film thus obtained was exposed to 30 mJ / cm ² using a mask aligner MA-10 manufactured by Mikasa Co., Ltd. through a negative mask. Then pre-bake at 100 ℃ for 15 minutes, develop at 25 ℃
A 1% by weight aqueous solution of sodium carbonate was run for 60 seconds to obtain a color filter.

The film thickness of each color of the color filter thus obtained is shown below.

When this color filter was subjected to a heat resistance test at 200 ° C. for 3 hours, no change in each color was observed and no change in weight was observed.

Comparative Example 1 The following resin composition was prepared as a photosensitive resin in the same manner as in Example 1, and a color filter was prepared in the same manner as in Application Example 1.

The following table shows the light energy required to form an image equivalent to that of Example 1 using the resin composition thus obtained.

Thus, the photosensitivity of the resin composition obtained in Comparative Example 1 showed extremely low sensitivity.

Comparative Example 2. A resin composition shown below was prepared as a photosensitive resin in the same manner as in Example 1, and a color filter was produced in the same manner as in Application Example 1.

The light energy required to form an image equivalent to that of Example 1 using the resin composition thus obtained is shown in the table below.

Thus, the sensitivity of the resin composition obtained in Comparative Example 2 was extremely low.

Example 2 Example 1 using the composition shown below as the photosensitive resin
The photopolymerizable resin composition for a color filter of the present invention was prepared in the same manner as in (1).

Application Example 2. Using the photopolymerizable resin composition for a color filter obtained in Example 2, a color filter was produced in the same manner as in Application Example 1. When this filter was subjected to a heat resistance test at 200 ° C. for 3 hours, discoloration and reduction in weight were not observed at all. In addition, when subjected to a light resistance test of carbon arc for 100 hours, no discoloration was observed.

(Effects of the Invention) It has become possible to manufacture a color filter which has a simple process, high resolution, excellent heat resistance and light resistance, and does not contain ionic impurities.

Claims (1)

(57) [Claims] 1. A composition comprising a photosensitive resin and a pigment, said photosensitive resin comprising a photopolymerizable compound having at least one ethylenically unsaturated double bond, a film-forming polymer binder and the following formula: Photopolymerizable resin composition for color filter containing compound represented by formula (I) Formula (I)