JP4403309B2 - Color filter - Google Patents

Description

  The present invention relates to a color filter.

  Examples of substances that have a very large π-electron chromophore and have a relatively high fastness to color green include phthalocyanine compounds such as polyhalogenated copper phthalocyanine and porphyrin compounds such as chlorophyll.

  Since the phthalocyanine compound has 8 nitrogen atoms in the heterocycle, the porphyrin compound has only 4 nitrogen atoms in the heterocycle, so the part excluding the porphyrin structure and the phthalocyanine structure In the performance comparison when the chemical structures are the same, the porphyrin compounds are more durable against attacks from various reagents such as acids, alkalis, oxidants, and active energy rays such as ultraviolet rays and near infrared rays. It has the advantage of being excellent.

  Polyhalogenated copper phthalocyanine is widely used as a green-emitting substance. However, since it has atoms such as chlorine and bromine in its molecule, recently there has been a concern about safety and environmental impact. Further, when polyhalogenated copper phthalocyanine is used for forming the green pixel portion of the color filter, sufficient brightness is not obtained compared to the red and blue pixel portions used in combination because of low coloring power. Furthermore, since polyhalogenated copper phthalocyanine has a bluish hue, a yellow pigment must be used in combination. In order to eliminate such drawbacks, a method has been proposed in which blue copper phthalocyanine and a yellow organic pigment are mixed to obtain a green color. There is a drawback that the initial green color is not maintained after a long period of time has passed since coloring.

  As an application that makes use of a characteristic unique to a porphyrin compound that is not included in a phthalocyanine compound, for example, an application such as an electrodeposition coating containing a compound having a porphyrin-based chromophore is known (see Patent Document 1). Here, chlorophyll and the like are described as examples of porphyrin compounds.

Further, an ink containing a tetrabenzoporphyrin-based compound as a dye and a color filter in which pixels are formed using the ink are known (see Patent Document 2). However, such a porphyrin compound is originally used as an alkali-soluble dye, and generally contains a water-soluble functional group, an organic solvent-compatible functional group, a functional group that becomes a salt by neutralization, and the like in the molecule. As a result, the durability against various reagents and active energy rays was still insufficient.

JP-A-53-21231 JP 2002-256182 A

  It is an object of the present invention to obtain a color filter having a green pixel portion that is safer and less burdened on the environment, and has excellent durability against various reagents and active energy rays and excellent coloring power.

  As a result of intensive studies to obtain a color filter having a green pixel portion that is safer, less burdened on the environment, and has excellent durability and coloring power in view of the above-described actual situation, the porphyrin compounds are: The inventors have found that tetrabenzoporphyrin having an aromatic ring has the characteristics described above, and have completed the present invention.

    That is, according to the present invention, in a color filter having red, green and blue pixel portions on a transparent substrate, the green pixel portion is represented by the general formula (1).

（式中、Ｍは２価から４価の金属または２個の水素原子を表す。）で示されるテトラベンゾポルフィリン化合物（以下、化合物（１）と言う。）により着色されていることを特徴とするカラーフィルターを提供する。

(Wherein M represents a divalent to tetravalent metal or two hydrogen atoms) and is colored by a tetrabenzoporphyrin compound (hereinafter referred to as compound (1)). Provide a color filter.

The compound (1) used in the present invention is a green pigment having a strong coloring power. For this reason, the color filter of the present invention has a remarkable effect that the coloring power is higher than that of the color filter having a green pixel portion using polyhalogenated copper phthalocyanine. Therefore, the film thickness of the obtained color filter becomes smaller, and higher transmittance can be obtained.

In addition, the color filter having the green pixel portion using the compound (1) has higher color purity than the color filter using polyhalogenated copper phthalocyanine, and the RGB color whose emission chromaticity is determined by the NTSC system. Since it is close to G (green) at the reproduction position, a yellow pigment for toning is not required or only a small amount is required. For this reason, color separation with time does not occur easily, and there is a particularly remarkable effect that a color filter having excellent light resistance can be provided. Furthermore, since the chemical structure does not contain a halogen atom, the compound (1) has a particularly remarkable effect that it can provide a safe color filter with less environmental load.

Moreover, the porphyrin compound dyed by introducing a substituent for solubilizing alkali was insufficient in durability against various reagents and active energy rays, but the compound (1) was converted into various reagents by pigmentation. And durability against active energy rays.

    Compound (1) is a known compound and is a metal-free tetrabenzoporphyrin represented by the formula (2) (in the general formula (1), M corresponds to two hydrogen atoms)

と、式（３）で示される金属テトラベンゾポルフィリン（一般式（１）において、Ｍが２価から４価の金属に対応）

And a metal tetrabenzoporphyrin represented by the formula (3) (in the general formula (1), M corresponds to a divalent to tetravalent metal)

（式中、Ｍは２価から４価の金属）とがある。これらの製造方法は例えばＩｎｏｒｇ．Ｃｈｅｍ．，２２４１，３０（１９９１）や、Ｊ．Ｃｈｅｍ．Ｓｏｃ．Ｐｅｒｋｉｎ Ｔｒａｎｓ．２，１０３（１９９５）等に記載されている。具体的には、例えばフタルイミドを出発物質としてカルボン酸誘導体および酢酸亜鉛とともに３００〜４００℃の高温で加熱することによって亜鉛テトラベンゾポルフィリンを製造することができる。他の金属テトラベンゾポルフィリンは、上記の亜鉛テトラベンゾポルフィリンを強酸中で長時間加熱還流して無金属テトラベンゾポルフィリンを得た後、所望する金属の酢酸塩と反応させることによって製造することができる。

(Wherein M is a divalent to tetravalent metal). These manufacturing methods are described in, for example, Inorg. Chem. , 2241, 30 (1991) and J.A. Chem. Soc. Perkin Trans. 2, 103 (1995). Specifically, for example, zinc tetrabenzoporphyrin can be produced by heating at a high temperature of 300 to 400 ° C. together with a carboxylic acid derivative and zinc acetate using phthalimide as a starting material. Other metal tetrabenzoporphyrins can be produced by heating and refluxing the above zinc tetrabenzoporphyrin in a strong acid for a long time to obtain a metal-free tetrabenzoporphyrin, and then reacting with the desired metal acetate. .

Specific metal atoms used as the metal tetrabenzoporphyrin include, for example,
Mg, Al, Fe, Co, Ni, Cu, Zn, Pd and the like can be mentioned, and divalent metals such as Co, Ni, Cu and Zn are preferable.

  The compound (1) produced by the above method is subjected to dry grinding in a pulverizer such as an attritor, ball mill, vibration mill, vibration ball mill, etc. By performing the finishing treatment, a tetrabenzoporphyrin pigment having an average primary particle diameter of 10 to 100 nm can be obtained. The tetrabenzoporphyrin pigment treated in this way has a better dispersibility and coloring power than before the finishing treatment, and a pigment that develops a brighter green color is obtained.

In order to obtain the color filter of the present invention, various yellow pigments are used in combination with the tetrabenzoporphyrin pigment using the compound (1) used in the present invention for yellowing to form the green pixel portion of the color filter. can do. Examples of yellow pigments that can be used here include C.I. I. Pigment YELLOW 83, 110, 138, 139, 150, 180, 185, and the like, can be mentioned, but in consideration of environmental load and safety, halogen atoms are included in the chemical structure. Does not contain C.I. I. It is particularly preferable to use together with Pigment YELLOW 139, 150, 180, 185 and the like. At this time, when the tetrabenzoporphyrin pigment of the present invention is used, the yellow pigment used in combination can be reduced as compared with the case of using a polyhalogenated copper phthalocyanine pigment.
The content of the yellow pigment for toning in the pigment component used for coloring the green pixel portion of the color filter is preferably less than 10% by mass, more preferably less than 5% by mass, and further Is preferably free of yellow pigment.
The yellow pigment is considered to have a problem in light resistance, and it is preferable that the yellow pigment is not contained as much as possible.

  The tetrabenzoporphyrin pigment used in the present invention can be used for forming a green pixel portion of a color filter by a known method. In producing the color filter of the present invention, a pigment dispersion method can be suitably employed.

A typical example of this method is a photolithography method, in which a photocurable composition to be described later is applied to a surface of a transparent substrate for a color filter on which the black matrix is provided, followed by heat drying (prebaking). After that, pattern exposure is performed by irradiating ultraviolet rays through a photomask to cure the photo-curable compound at a location corresponding to the pixel portion, and then developing the unexposed portion with a developer, thereby developing the non-pixel portion. In which the pixel portion is fixed to the transparent substrate. In this method, a pixel portion made of a cured colored film of a photocurable composition is formed on a transparent substrate.
A color filter having red, green, and blue pixels at predetermined positions is prepared by preparing a photocurable composition to be described later for each color of red, green, and blue and repeating the above-described operation. Can do. A green pixel portion is formed using a tetrabenzoporphyrin pigment using the compound (1) used in the present invention.

In addition, in order to prepare the photocurable composition for forming a red pixel part and a blue pixel part, a well-known red pigment and a blue pigment can be used. Examples of the pigment for forming the red pixel portion include C.I. I. Pigment Red 177, 209, 254, and the like are pigments for forming a blue pixel portion, such as C.I. I. Pigment Blue 15, 60 and the like. In forming the red pixel portion and the blue pixel portion, a yellow pigment or a purple pigment can be used in combination. Thereafter, if necessary, in order to thermally cure the unreacted photocurable compound, the entire color filter can be heat-treated (post-baked).

  Examples of a method for applying a photocurable composition described later on a transparent substrate such as glass include a spin coat method, a roll coat method, and an ink jet method.

  Although the drying conditions of the coating film of the photocurable composition apply | coated to the transparent substrate differ also with the kind of each component, a compounding ratio, etc., they are 50-150 degreeC and are about 1 to 15 minutes normally. This heat treatment is generally referred to as “pre-baking”. Moreover, as light used for photocuring of a photocurable composition, it is preferable to use the ultraviolet-ray or visible light of a wavelength range of 200-500 nm. Various light sources that emit light in this wavelength range can be used.

  Examples of the developing method include a liquid piling method, a dipping method, and a spray method. After exposure and development of the photocurable composition, the transparent substrate on which the necessary color pixel portions are formed is washed with water and dried. The color filter thus obtained is subjected to heat treatment (post-baking) at 100 to 280 ° C. for a predetermined time by a heating device such as a hot plate or an oven to remove volatile components in the coating film and at the same time photocuring. The unreacted photocurable compound remaining in the cured colored film of the curable composition is thermally cured to complete the color filter.

  The above-described photocurable composition (also referred to as a pigment-dispersed photoresist) for forming the pixel portion of the color filter includes a tetrabenzoporphyrin pigment used in the present invention, a dispersant, a photocurable compound, and an organic solvent. Can be prepared by mixing them using a thermoplastic resin as necessary. When the colored resin film that forms the pixel portion requires toughness that can withstand baking performed in the actual production of a color filter, only the photocurable compound is used in preparing the photocurable composition. In addition, it is essential to use this thermoplastic resin in combination. When a thermoplastic resin is used in combination, it is preferable to use an organic solvent that dissolves it.

  As a method for producing the photocurable composition, a tetrabenzoporphyrin pigment used in the present invention, an organic solvent and a dispersant are used as essential components, and these are mixed and stirred and dispersed so as to be uniform. After preparing a pigment dispersion (sometimes called a colored paste) for forming the pixel portion of the filter, add a photocurable compound and, if necessary, a thermoplastic resin or a photopolymerization initiator. In addition, the method of using the photocurable composition is common.

  Examples of the dispersant include Dispavik 130, Dispersic 161, Dispersic 162, Dispersic 163, Dispersic 170, and Fuka 46 and Fuka 47 of Fuka. In addition, a leveling agent, a coupling agent, a cationic surfactant, and the like can be used together.

  Examples of the organic solvent include aromatic solvents such as toluene, xylene, and methoxybenzene, acetate solvents such as ethyl acetate and butyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and ethoxyethyl propionate. Propionate solvents, alcohol solvents such as methanol and ethanol, ether solvents such as butyl cellosolve, propylene glycol monomethyl ether, diethylene glycol ethyl ether and diethylene glycol dimethyl ether, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, fats such as hexane Group hydrocarbon solvents, N, N-dimethylformamide, γ-butyrolactam, N-methyl-2-pyrrolidone, ani Emissions, nitrogen compound-based solvent such as pyridine, a lactone-based solvents such as γ- butyrolactone, carbamic acid esters such as a mixture of 48:52 of methyl carbamate and ethyl carbamate acid. As the organic solvent, a propionate-based, alcohol-based, ether-based, ketone-based, nitrogen compound-based or lactone-based polar solvent that is water-soluble is particularly suitable. When a water-soluble organic solvent is used, water can be used in combination.

Examples of the thermoplastic resin used for preparing the photocurable composition include urethane resins, acrylic resins, polyamic acid resins, polyimide resins, styrene maleic acid resins, styrene maleic anhydride resins, and the like. It is done. Examples of the photocurable compound include 1,6-hexanediol diacrylate, ethylene glycol diacrylate, neopentyl glycol diacrylate, triethylene glycol diacrylate, bis (acryloxyethoxy) bisphenol A, 3-methylpentanediol di Multifunctional with relatively low molecular weight such as bifunctional monomer such as acrylate, trimethylol propaton triacrylate, pentaerythritol triacrylate, tris (2-hydroxyethyl) isocyanate, dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate Polyfunctional monomers with relatively large molecular weight such as monomer, polyester acrylate, polyurethane acrylate, polyether acrylate, etc. It is below.
Examples of the photopolymerization initiator include acetophenone, benzophenone, benzyldimethylketanol, benzoyl peroxide, 2-chlorothioxanthone, 1,3-bis (4′-azidobenzal) -2-propane, 1,3-bis (4 '-Azidobenzal) -2-propane-2'-sulfonic acid, 4,4'-diazidostilbene-2,2'-disulfonic acid and the like.

  Using each of the above materials, 300 to 1000 parts by mass of an organic solvent and 0 to 100 parts by mass of a dispersant are stirred and dispersed so as to be uniform per 100 parts by mass of the tetrabenzoporphyrin pigment used in the present invention. Thus, the pigment dispersion can be obtained. Subsequently, the total amount of the thermoplastic resin and the photocurable compound is 3 to 20 parts by mass per 1 part by mass of the pigment containing the tetrabenzoporphyrin pigment used in the present invention. A photocurable composition for forming a green pixel portion of a color filter by adding 05 to 3 parts by mass of a photopolymerization initiator and, if necessary, further adding an organic solvent and stirring and dispersing so as to be uniform. be able to.

  As the developer, a known and commonly used organic solvent or alkaline aqueous solution can be used. In particular, when the photo-curable composition contains a thermoplastic resin or a photo-curable compound, and at least one of these has an acid value and exhibits alkali solubility, washing with an aqueous alkali solution is performed on the pixel portion. It is effective for formation.

  The manufacturing method of the color filter by the photolithography method among the pigment dispersion methods has been described in detail, but the color filter of the present invention can be applied to other electrodeposition methods, transfer methods, micelle electrolysis methods, PVED (Photovoltaic Electrodeposition) methods, etc. A color filter may be manufactured by forming a pixel portion by a method.

  In addition to the color filter, the tetrabenzoporphyrin compound can be suitably used, for example, as a green colorant for inks, paints, plastic molded products, and the like.

  EXAMPLES Next, although an Example demonstrates this invention still in detail, this invention is not limited by these examples. Hereinafter, unless otherwise noted, parts means parts by mass.

[Synthesis Example 1]
J. et al. Chem. Soc. Perkin Trans. 2,103 (1995), zinc tetrabenzoporphyrin was prepared from 10 parts potassium phthalimide, 5.9 parts zinc acetate and 35.4 parts sodium acetate. 1 part of this zinc tetrabenzoporphyrin, 7 parts of crushed sodium chloride, 1 part of diethylene glycol and 0.09 part of xylene were charged into a double-arm kneader and kneaded at 100 ° C. for 6 hours. After kneading, the kneaded product is taken out in 100 parts of water at 80 ° C., stirred for 1 hour, filtered, washed with hot water, dried and pulverized, and a zinc tetrabenzoporphyrin pigment having an average particle size of about 30 nm (general formula (1) M corresponds to Zn).

[Synthesis Example 2]
Zinc tetrabenzoporphyrin was added to an acetic acid / hydrochloric acid mixed solution (4: 1 v / v) and heated to reflux for 2 hours. Metal-free tetrabenzoporphyrin was obtained by filtering the precipitate. Grinding was carried out under the same conditions as in Synthesis Example 1 to obtain a metal-free tetrabenzoporphyrin pigment having an average particle diameter of about 30 nm (in the general formula (1), M corresponds to two hydrogen atoms).

[Synthesis Example 3]
Metal-free tetrabenzoporphyrin was added to dimethylformamide together with copper acetate and heated to reflux for 1.5 hours. After cooling, copper tetrabenzoporphyrin was obtained by filtering the precipitate. In the same manner as in Synthesis Example 1, a copper tetrabenzoporphyrin pigment (M in the general formula (1) corresponds to Cu) having an average particle diameter of about 40 nm was obtained.

[Examples 1 to 3, Comparative Example 1]
Each of the tetrabenzoporphyrin pigments obtained in Synthesis Examples 1 to 3 and a commercially available polyhalogenated copper phthalocyanine pigment (Fastogen Green 2YK-CF; CI Pigment Green 36, manufactured by Dainippon Ink & Chemicals, Inc.) The green pixel portion of each color filter was produced by photolithography using the green pigment.

  The production method of the color filter green pixel part is 17 parts of each pigment, 2.5 parts of N, N-dimethylformamide (organic solvent), 17.0 parts of Dispersic 161 (dispersant manufactured by BYK Chemie), Euker Ester EEP ( 0.53.5φ Sepul beads were added to 63.5 parts of Union Carbide Organic Solvent) and dispersed with a paint conditioner (Toyo Seiki Co., Ltd.) for 1 hour to obtain a pigment dispersion (colored paste). 75.00 parts of this pigment dispersion and Aronix M7100 (polyester acrylate manufactured by Toa Gosei Kagaku Kogyo Co., Ltd.) Acrylate, corresponding to a photocurable compound) 5.00 parts, KAYACURE BP-100 (Nippon Kayaku Co., Ltd., benzophenone, corresponding to a photopolymerization initiator) 1.00 parts and Euker ester EEP 13.5 parts Was stirred with a dispersion stirrer to obtain a photocurable composition for forming a color filter green pixel portion. This composition was applied to 1 mm thick glass so as to have a dry film thickness of 1 μm.

Next, pattern exposure with ultraviolet rays was performed through a photomask, and then an unexposed portion was washed with an organic solvent (isopropanol) to obtain a green pixel portion for a color filter.
The green color image portion for the color filter thus produced was evaluated for the coloring power using the absorbance value in the spectrophotometer, and the green image portion for the color filter of Examples 1 to 3 was polyhalogenated. The coloring power was higher than that of copper halide phthalocyanine. Table 1 summarizes the green pigments used in Examples 1 to 3 and Comparative Example 1 and the evaluation of coloring power.

[Example 4, Comparative Example 2]
The photocurable composition containing the polyhalogenated copper phthalocyanine pigment of the comparative example was applied to a 1 mm thick glass so as to have a dry film thickness of 3 μm. The following steps were performed for the color filter green pixel portion in the same manner as in the comparative example. The following evaluation was performed about this and the green pixel part containing the above-mentioned copper tetrabenzoporphyrin pigment. The results are shown in Table 2.

<Color purity test>
The x and y values in the CIE color system were measured using a spectrophotometer.

<Half-width test>
Using a spectrophotometer, the full width at half maximum at the transmittance peak at a wavelength of 500 to 600 nm was measured. The smaller the half width, the higher the color purity.

From the evaluation results shown in Table 1, the green image portion using tetrabenzoporphyrin in the color filter has a light emission chromaticity of the green image portion as compared with the color filter using polyhalogenated copper phthalocyanine in the green image portion. Since it is close to the RGB (green) reproduction position defined by the NTSC system, a small amount of yellow pigment is required for toning. Further, since the half width at the maximum transmission wavelength is small, it can be said that the color purity is high.

In order to make the pigment of Comparative Example 2 the same color as the pigment of Example 4, C.I. I. A green pixel portion for a color filter was obtained in the same manner except that 3 parts of Pigment Yellow 150 (the content of the yellow pigment in the pigment component was 17.6% by mass) was added. When this and the green pixel portion of Example 4 were irradiated with xenon light for 96 hours using an Atlas weatherometer manufactured by Toyo Seiki, no fading was observed in the green image portion of Example 4 by visual observation. On the other hand, the polyhalogenated copper phthalocyanine in which the pigment of Comparative Example 2 was toned exhibited fading.

[Example 5]
In place of the tetrabenzoporphyrin pigment obtained in Synthesis Example 1, C.I. I. Pigment Red 254 (diketopyrrolopyrrole red organic pigment) and C.I. I. Except for using Pigment Blue 15: 6 (ε-type copper phthalocyanine blue organic pigment), red and blue photocurable compositions were prepared in the same manner as in the green pixel portion. A red pixel portion and a blue pixel portion were formed together with a green pixel portion containing the pigment of Synthesis Example 1 to obtain a color filter provided with RGB pixel portions.

Claims (5)

In a color filter having red, green and blue pixel portions on a transparent substrate, the green pixel portion is represented by the general formula (1).

A color filter characterized by being colored with a tetrabenzoporphyrin compound represented by the formula (wherein M represents a divalent to tetravalent metal or two hydrogen atoms). The color filter according to claim 1, wherein, in the general formula (1), M is any one of Cu, Co, Ni, and Zn. The color filter according to claim 1 or 2, wherein the green pixel portion is colored with a green pigment represented by the general formula (1). The color filter according to claim 3, wherein the content of the yellow pigment in the pigment component used for coloring the green pixel portion is less than 10% by mass. The color filter according to any one of claims 1 to 4, wherein an average particle size of the tetrabenzoporphyrin compound represented by the general formula (1) is 10 to 100 nm.