TWI898037B - Color filter pigments, coloring compositions, and color filters - Google Patents

Abstract

The color filter pigment of the present invention is used to form a coating in the green pixel portion of a color filter. When the coating has a thickness of 1.5 μm to 2.4 μm and is composed of 1.25 parts of resin per part of the pigment, the xy chromaticity coordinate region defined by equations (A) to (D) can be displayed in the CIE XYZ colorimetric system when color measurement is performed using only light source C. The pigment comprises a compound represented by formula (1), namely, a zinc phthalocyanine halide pigment. The average number of halogen atoms in one molecule of the compound is 0.2 or more and 10 or less, the average number of bromine atoms in one molecule of the compound is 0.1 or more and 10 or less, and the average number of chlorine atoms in one molecule of the compound is 0.1 or more and less than 2. Furthermore, formulas (A) to (D) and formula (1) are as described in this specification.

Description

Color filter pigments, coloring compositions, and color filters

The present invention relates to a color filter pigment, a coloring composition, and a color filter.

In a display device such as a liquid crystal display device, a color filter having pixel portions of red, green, and blue colors is used to convert the color of light from a light source to display an image. There are various standards related to color reproducibility for this type of display device, and it is required that it can display colors with prescribed chromaticity in compliance with each standard. Therefore, the color filter used in the display device also needs to convert the light from the light source into light with a chromaticity corresponding to the standard.

The colorant for the green pixel portion of the color filter requires (1) high brightness and (2) high color reproduction. To achieve (1) high brightness, it is important to select a pigment with a high transmittance to the backlight, and thus use the pigment Green 58 as the main pigment. Current displays are designed with a high brightness based on the sRGB standard (green pixel is (x, y) = (0.300, 0.600)), and LED-YAG is widely used as the backlight. To achieve (2) high color reproduction, a pigment that can achieve vivid color display is required. One proposal uses a green photosensitive resin composition containing Green 7 and Yellow 185 to form green pixels, achieving high color reproduction. However, Green 7 has a low transmittance, resulting in lower display brightness. Green 59, a new high-color-rendering pigment, achieves higher brightness when compared to Green 7 when using filters of the same film thickness. To meet high-color-rendering display standards (such as Adobe RGB or DCI-P3), thicker filters can be designed. However, this can lead to issues such as insufficient filter hardening during the exposure step. Therefore, it is preferable to use pigments that achieve vivid color display. For the reasons described above, green pigment 58 is used in high-brightness displays, and green pigment 59 is used in high-color-rendering displays. Color filters such as those described above are described, for example, in the following patent documents 1 to 3. Prior Art Documents Patent Documents

[Patent Document 1] Japanese Patent Application Publication No. 2012-123302 [Patent Document 2] Japanese Patent Application Publication No. 2006-045399 [Patent Document 3] International Publication No. 2015/118720

[The problem that the invention aims to solve]

In recent years, BT2020 has garnered attention as a more vibrant color standard than more familiar Adobe RGB or DCI-P3. BT2020 uses a green pixel with (x, y) = (0.170, 0.797) corresponding to 532 nm light. However, achieving this pixel using a filter with a green 58 or 59 color and a standard light source is difficult. The green pixel portion of the filter must transmit light near 532 nm and absorb all other light. While recent light source development has progressed toward narrowing wavelengths to near 532 nm, unwanted light is included at wavelengths shorter than and longer than 532 nm, necessitating the use of appropriate filters.

To create a green filter that complies with the emerging color standard, BT2020, the challenge lies in achieving chromaticity coordinates close to (x, y) = (0.170, 0.797) using thin films. Furthermore, to minimize display power consumption, the challenge lies in achieving higher brightness with chromaticity coordinates close to (x, y) = (0.170, 0.797).

Therefore, the object of this invention is to provide a pigment that can be used to create a color filter with a thin film thickness and excellent brightness in the green pixel portion of the emerging BT2020 color standard. [Technical Solution]

The inventors have discovered that the above-mentioned problem can be solved by using a pigment comprising the following: a zinc phthalocyanine halide pigment having a blue hue (cyan-blue) under a light source corresponding to BT2020 and having a specific number of halogen atoms, which exhibits a chromaticity coordinate region close to (x, y) = (0.170, 0.797) in the CIE XYZ color system.

That is, the present invention is as follows. Item 1. A color filter pigment, which is used to form a coating in the green pixel portion of a color filter, wherein when the film thickness of the coating is set to 1.5 μm to 2.4 μm and the composition is set to 1.25 parts of resin per part of the pigment, the xy chromaticity coordinate region defined by the following equations (A) to (D) can be displayed in the CIE XYZ colorimetric system when color measurement is performed using only light source C: Equation (A) y = -1.766x + 0.618 (where x is 0.10 ≤ x ≤ 0.17), Equation (B) y = 5.889x - 0.683 (where x is 0.15 ≤ x ≤ 0.17), Equation (C) y=0.125x+0.181 (wherein x is 0.07≦x≦0.15), Formula (D) y=8.380x-0.397 (wherein x is 0.07≦x≦0.10), and the pigment comprises a compound represented by the following formula (1), namely, a halogenated zinc phthalocyanine pigment, wherein the average number of halogen atoms in one molecule of the compound is 0.2 or more and 10 or less, the average number of bromine atoms in one molecule of the compound is 0.1 or more and 10 or less, and the average number of chlorine atoms in one molecule of the compound is 0.1 or more and less than 2, [In formula (1), X ¹ to X ¹⁶ each independently represent a hydrogen atom or a halogen atom.] Item 2. A coloring composition comprising the color filter pigment described in Item 1 and a solvent. Item 3. A color filter having a coating film formed of the color filter pigment described in Item 1 on a green pixel portion. [Effects of the Invention]

The pigment of the present invention can provide a pigment having a thin film thickness in the green pixel portion and excellent brightness when manufactured into a color filter.

[Color filter pigment] The pigment of the present invention is used to form a coating in the green pixel portion of a color filter, and the pigment comprises a compound represented by the following formula (1), namely, a halogenated zinc phthalocyanine pigment, wherein the average number of halogen atoms in one molecule of the compound is not less than 0.2 and not more than 10, the average number of bromine atoms in one molecule of the compound is not less than 0.1 and not more than 10, and the average number of chlorine atoms in one molecule of the compound is not less than 0.1 and not more than 2. [In formula (1), X ¹ to X ¹⁶ each independently represent a hydrogen atom or a halogen atom].

Examples of halogen atoms in the zinc phthalocyanine halogenide pigment, which is a compound represented by formula (1), include fluorine, chlorine, bromine, and iodine. The average number of halogen atoms in one molecule is as described above, and the average number of bromine and chlorine atoms in the zinc phthalocyanine halogenide pigment is as described above.

From the perspective of further improving coloring power, the average number of halogen atoms in the molecule of compound 1 represented by formula (1) in the zinc halogenide phthalocyanine pigment is preferably 0.5 to 9.0, more preferably 1.0 to 7.0. From the perspective of obtaining better brightness, the average number of halogen atoms is preferably 2.0 to 9.0, more preferably 3.5 to 8.0.

From the perspective of achieving superior brightness and coloring power, the average number of bromine atoms in the molecule of the compound 1 represented by formula (1) in the zinc halogenide phthalocyanine pigment is preferably 9.0 or less, more preferably 6.5 or less. From the perspective of further achieving superior brightness, the average number of bromine atoms is 0.1 or more, preferably 1.0 or more, and more preferably 2.0 or more.

From the perspective of achieving superior brightness and coloring power, the average number of chlorine atoms in the molecule of compound 1 represented by formula (1) in the zinc halogenide phthalocyanine pigment is preferably 1.9 or less, more preferably 1.6 or less, and further preferably 1.3 or less. From the perspective of achieving superior brightness, the average number of chlorine atoms is 0.1 or more, preferably 0.12 or more, more preferably 0.15 or more, and further preferably 0.2 or more.

The number of halogen atoms (e.g., bromine and chlorine atoms) can be determined by fluorescent X-ray analysis. Specifically, the number of halogen atoms per zinc atom can be calculated based on the mass ratio of zinc atoms to each halogen atom in the zinc phthalocyanine halide pigment.

Zinc halogenide phthalocyanine pigments may be composed of one or more types of particles. The average primary particle size of the zinc halogenide phthalocyanine pigment (average primary particle size) may be 0.01 μm or greater, 0.015 μm or greater, or 0.02 μm or greater. The average primary particle size of the zinc halogenide phthalocyanine pigment may be 0.20 μm or less, 0.10 μm or less, or 0.07 μm or less. The average primary particle size here refers to the average of the primary particle lengths and can be determined by measuring the primary particle lengths in the same manner as the average aspect ratio described below.

The average aspect ratio of the primary particles of the zinc phthalocyanine halogenide pigment is, for example, 1.2 or greater, 1.3 or greater, 1.4 or greater, or 1.5 or greater. The average aspect ratio of the primary particles of the zinc phthalocyanine halogenide pigment is, for example, less than 2.0, 1.8 or less, 1.6 or less, or 1.4 or less. Zinc phthalocyanine halogenide pigments having such average aspect ratios can achieve superior contrast.

The zinc phthalocyanine halide pigment having an average aspect ratio of primary particles in the range of 1.0 to 3.0 preferably does not contain primary particles having an aspect ratio of 5 or greater, more preferably does not contain primary particles having an aspect ratio of 4 or greater, and even more preferably does not contain primary particles having an aspect ratio exceeding 3.

The aspect ratio and average aspect ratio of primary particles can be measured using the following method. First, use a transmission electron microscope (e.g., JEM-2010, manufactured by JEOL Ltd.) to image the particles within the field of view. Next, measure the longer diameter (major diameter) and shorter diameter (minor diameter) of each primary particle in the two-dimensional image. The ratio of the longer diameter to the shorter diameter is defined as the aspect ratio of the primary particle. Furthermore, the average of the longer and shorter diameters of 40 primary particles is calculated using these values to determine the ratio of the longer diameter to the shorter diameter, which is then defined as the average aspect ratio. In this case, the sample of zinc phthalocyanine halide pigment is ultrasonically dispersed in a solvent (e.g., cyclohexane) and then photographed under a microscope. Alternatively, a scanning electron microscope can be used instead of a transmission electron microscope.

The zinc phthalocyanine halide pigment of the present invention can be obtained by synthesizing a crude pigment composed of at least a zinc phthalocyanine halide compound. If necessary, the crude pigment may be further pigmented.

The step of synthesizing the zinc phthalocyanine halogenide crude pigment may also include synthesizing the zinc phthalocyanine halogenide compound by a known production method such as a chlorosulfonic acid method, a halogenated phthalocyanine method, or a melt method.

The chlorosulfonic acid method involves dissolving zinc phthalocyanine in a sulfur oxide solvent such as chlorosulfonic acid and then adding chlorine or bromine to the solution for halogenation. The reaction is typically carried out at a temperature of 20-120°C for 3-20 hours.

For example, the halogenated phthalonitrile method involves using phthalic acid or phthalonitrile in which some or all of the hydrogen atoms on the aromatic ring are substituted with halogen atoms such as bromine or chlorine, and metallic zinc or a zinc metal salt as appropriate starting materials to synthesize the corresponding halogenated zinc phthalocyanine compound. A catalyst such as ammonium molybdate may also be used as needed. The reaction is typically carried out at a temperature of 100-300°C for 7-35 hours.

As a melting method, the following method can be cited, namely, zinc phthalocyanine is halogenated with a halogenating agent in a melt at about 10 to 170°C composed of one or a mixture of two or more compounds that serve as solvents during halogenation. The above-mentioned compounds include aluminum halides such as aluminum chloride and aluminum bromide, titanium halides such as titanium tetrachloride, alkali metal halides or alkaline earth metal halides (hereinafter referred to as alkali (earth) metal halides) such as sodium chloride and sodium bromide, and sulfinyl chloride.

A preferred aluminum halide is aluminum chloride. In the above method using aluminum halide, the amount of aluminum halide added is generally at least 3 times the molar amount of zinc phthalocyanine, preferably 10 to 20 times the molar amount.

Aluminum halide can be used alone, but combining an alkali (earth) metal halide with aluminum halide can further lower the melting temperature, resulting in more favorable processing. Sodium chloride is a preferred alkali (earth) metal halide. The amount of alkali (earth) metal halide added is preferably 1-15 parts by weight per 10 parts by weight of aluminum halide, within the range necessary to produce a molten salt.

Examples of halogenating agents include chlorine, sulfonyl chloride, and bromine.

The halogenation temperature is preferably 10-170°C, more preferably 30-140°C. Furthermore, pressure may be applied to accelerate the reaction. The reaction time can be 5-100 hours, preferably 30-45 hours.

The melting method, which uses two or more of the aforementioned compounds simultaneously, is preferred because it allows for the precise control of the ratio of specific halogen atoms in the resulting zinc phthalocyanine halide compound by adjusting the ratio of chloride, bromide, and iodide in the molten salt, or by varying the amount of chlorine, bromine, and iodine introduced, as well as the reaction time. Furthermore, the melting method minimizes decomposition of the raw materials during the reaction, resulting in a higher yield from the raw materials. Furthermore, the reaction can be carried out using inexpensive equipment, without the need for strong acids.

By optimizing the method of adding raw materials, the type and amount of catalyst used, the reaction temperature, and the reaction time, a zinc phthalocyanine halide compound with a halogen atom composition different from that of existing zinc phthalocyanine halides can be obtained.

After the reaction is complete, either of the above methods can be used to obtain a crude zinc phthalocyanine halide pigment by placing the resulting mixture into an acidic aqueous solution such as water or hydrochloric acid to precipitate the resulting zinc phthalocyanine halide compound. This crude zinc phthalocyanine halide pigment can be used directly, but is preferably then filtered, washed with water or sodium bisulfate, sodium bicarbonate, or sodium hydroxide, and optionally washed with an organic solvent such as acetone, toluene, methanol, ethanol, or dimethylformamide, followed by drying. Alternatively, the crude zinc phthalocyanine halide pigment can be dry-ground in a grinder, ball mill, vibrating mill, or vibrating ball mill before use.

The zinc phthalocyanine halide crude pigment obtained through the above steps has the same composition as the zinc phthalocyanine halide pigment. The zinc phthalocyanine halide crude pigment obtained through the above steps can be used directly as a pigment, or it can be further processed into a pigment.

In the pigmenting step of the crude zinc phthalocyanine halide pigment, for example, the crude zinc phthalocyanine halide pigment is kneaded and then ground to obtain the zinc phthalocyanine halide pigment. The pigmenting step of the crude zinc phthalocyanine halide pigment may also be performed by kneading the crude zinc phthalocyanine halide pigment with an inorganic salt and an organic solvent. Kneading can be performed using, for example, a kneader or a mixer. Furthermore, the present invention may include a step of cooling the crude zinc phthalocyanine halide pigment to, for example, -50°C to -10°C and simultaneously grinding it with a liquid organic solvent (a micronizing step).

As the inorganic salt, a water-soluble inorganic salt is preferably used. For example, sodium chloride, potassium chloride, sodium sulfate, and the like are preferably used. The average particle size of the inorganic salt is preferably 0.5 to 50 μm. Such an inorganic salt can be easily obtained by finely grinding a conventional inorganic salt.

To easily obtain a pigment having an average primary particle size within the above range, it is preferred to use a larger amount of the inorganic salt relative to the amount of the coarse pigment. Specifically, the amount of the inorganic salt used is preferably 5 to 20 parts by mass, more preferably 7 to 15 parts by mass, per 1 part by mass of the coarse pigment.

The organic solvent can be one that does not dissolve the crude pigment and inorganic salt. It is preferred to use an organic solvent that can inhibit crystal growth. Water-soluble organic solvents are preferred. Examples of the organic solvent that can be used include diethylene glycol, glycerol, ethylene glycol, propylene glycol, liquid polyethylene glycol, liquid polypropylene glycol, 2-(methoxyethoxy)ethanol, 2-butoxyethanol, 2-(isopentyloxy)ethanol, 2-(hexyloxy)ethanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol, triethylene glycol monomethyl ether, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, trimethyl phosphate, 4-butyrolactone, propylene carbonate, N-methyl-2-pyrrolidone, methanol, ethylene cyanohydrin, 1,2,4-butanetriol, 1,2,5-pentanetriol, and 1,3-butanediol. The amount of the organic solvent (e.g., a water-soluble organic solvent) used is not particularly limited, but is preferably 0.01 to 5 parts by mass per 1 part by mass of the crude pigment.

From the perspective of preventing solidification due to cooling, the melting point of the organic solvent is preferably below -10°C, more preferably below -15°C, and even more preferably below -20°C. The melting point of the organic solvent may be above -60°C. When the organic solvent comprises multiple organic solvents, it is preferred that at least one of the organic solvents has a melting point within the above range, and it is more preferred that the melting point of the organic solvents as a whole is within the above range.

From the perspective of making it difficult to dissolve the crude zinc phthalocyanine halide pigment, thus facilitating the production of finer pigment particles, the organic solvent preferably has an Ra value of 5 or greater with zinc phthalocyanine. The Ra value represents the distance between two substances, calculated from the Hansen Solubility Parameters (HSP)—the dispersion term (δd), polar term (δp), and hydrogen bond term (δh). Given that the dispersion term (δd), polar term (δp), and hydrogen bond term (δh) of zinc phthalocyanine are 16.0, 7.7, and 9.5, respectively, if the dispersion term of the organic solvent is set to δd1, the polar term is set to δp1, and the hydrogen bond term is set to δh1, the distance (Ra value) between the HSP of the organic solvent and the HSP of zinc phthalocyanine can be calculated using the following formula (I). (Ra) ² = 4(δd1-16.0) ² + (δp1-7.7) ² + (δh1-9.5) ² ... (I)

Hansen solubility parameters for various organic solvents are listed in, for example, "Hansen Solubility Parameters: A Users Handbook" by Charles M. Hansen. For organic solvents where Hansen solubility parameters are not listed, they can be estimated using computer software (Hansen Solubility Parameters in Practice).

From the perspective of making the zinc phthalocyanine halogenide crude pigment more difficult to dissolve, the Ra value of the organic solvent and zinc phthalocyanine is preferably 10 or greater. From the perspective of easily wetting the pigment, the Ra value of the organic solvent and zinc phthalocyanine is preferably 40 or less, more preferably 30 or less, and even more preferably 25 or less.

When the organic solvent comprises multiple organic solvents, it is preferred that the distance (Ra value) between the HSP of the organic solvent as a whole and the HSP of zinc phthalocyanine halide, calculated based on the dispersion force term, polarity term, and hydrogen bond term of each organic solvent and the mixing ratio of each organic solvent, be within the above range.

In the micronization step, water is preferably not used. The amount of water used is, for example, 20 parts by mass or less, 10 parts by mass or less, or 5 parts by mass or less, per 100 parts by mass of the crude zinc phthalocyanine halide pigment.

Cooling can be achieved using a cooling device such as a chiller (a cooling water circulation system). When using a chiller, the refrigerant temperature within the chiller can be set to, for example, -50°C to -10°C, thereby cooling the zinc phthalocyanine halide crude pigment to approximately -50°C to -10°C. To achieve finer pigment particles, the cooling temperature is preferably below -20°C, more preferably below -30°C. To prevent increased viscosity and the resulting load on the grinding device, the cooling temperature may exceed -50°C.

The grinding in the micronization step can be performed using, for example, a kneader or a mixer. The grinding time (e.g., mixing time) can be 1 to 60 hours.

When an inorganic salt and an organic solvent are used in the micronization step, a mixture containing zinc phthalocyanine halide pigment, the inorganic salt, and the organic solvent can be obtained. The organic solvent and the inorganic salt can also be removed from the mixture. If necessary, the solid material composed mainly of zinc phthalocyanine halide pigment can be washed, filtered, dried, or pulverized.

Cleaning can be done with either water or hot water. This cleaning cycle can be repeated 1 to 5 times. When using water-soluble inorganic salts or water-soluble organic solvents, the organic solvents and salts can be easily removed by water washing. If necessary, acid cleaning, alkaline cleaning, or organic solvent cleaning can also be performed.

Examples of drying after washing and filtering include batch or continuous drying, where the pigment is heated to 80-120°C using a heat source installed in the dryer to dehydrate and/or desolvate the pigment. Typical dryers include box dryers, belt dryers, and spray dryers. Spray drying using a spray dryer is particularly preferred for slurry preparation, as it facilitates dispersion. Furthermore, post-drying pulverization is not intended to increase the specific surface area or reduce the average primary particle size. Instead, it is used to disperse and powderize the pigment when drying the pigment in a sloped shape, such as when drying with a box dryer or belt dryer. For example, pulverization by a mortar, hammer mill, disc mill, pin mill, jet mill, etc. can be cited.

In the above method, a coating resin can be coexisted with the coarse pigment during pigmentation. By coexisting with the resin during pigmentation, the active surface (active growth surface) of the particles is stabilized by the coating resin. This mitigates directional bias in particle growth, making it easier to obtain a pigment with a relatively small average vertical and horizontal size. Using this pigment can improve the contrast of the pixel area.

The coating resin is preferably one containing acidic groups, such as a resin containing a polymer containing acidic groups. Because acidic groups interact with the active surface (active growth surface), the inclusion of acidic groups in the resin facilitates the production of pigments with relatively small average primary particle widths. Examples of acidic groups include carboxyl groups, sulfonic acid groups, phosphate groups, and their ammonium salts. Carboxyl groups are particularly preferred for achieving superior contrast.

The pigment may further contain other components in addition to the above-mentioned zinc phthalocyanine halide pigment and coating resin. Examples of such other components include well-known phthalocyanine derivatives.

The zinc halogenide phthalocyanine pigment of the present invention has a unique blue-blue color. Compared with conventional high-zinc halogenide phthalocyanine pigments, it has a blue-blue hue rather than a yellow-toned hue, and can produce hues that conventional high-zinc halogenide phthalocyanine pigments cannot achieve.

Furthermore, the halogenated zinc phthalocyanine pigment of the present invention, when formed into a coating having a composition of 1.25 parts of resin per part of pigment, and a film thickness of 1.5 μm to 2.4 μm, exhibits the xy chromaticity coordinate region defined by the following equations (A) to (D) in the CIE XYZ colorimetric system when colorimetry is performed using only illuminant C. Formula (A) y = -1.766x + 0.618 (where x is 0.10 ≤ x ≤ 0.17), Formula (B) y = 5.889x - 0.683 (where x is 0.15 ≤ x ≤ 0.17), Formula (C) y = 0.125x + 0.181 (where x is 0.07 ≤ x ≤ 0.15), Formula (D) y = 8.380x - 0.397 (where x is 0.07 ≤ x ≤ 0.10). If the above formulas (A), (B), (C), and (D) are plotted on a chromaticity diagram (x-axis: chromaticity x, y-axis: chromaticity y), they are as shown in Figure 3, Formulas A, B, C, and D. The area enclosed by the formulas A, B, C, and D is the chromaticity coordinate area A.

Furthermore, in order to achieve excellent brightness when fabricated into a color filter, the halogenated zinc phthalocyanine pigment of the present invention preferably exhibits an xy chromaticity coordinate region bounded by the following equations (C), (E), (F), and (G). This region, when represented on a chromaticity diagram, is represented by equations C, E, F, and G in Figure 3. The region bounded by equations C, E, F, and G is chromaticity coordinate region B. Formula (C): y = 0.125x + 0.181 (where x is 0.07 ≤ x ≤ 0.15), Formula (E): y = -1.333x + 0.503 (where x is 0.10 ≤ x ≤ 0.16), Formula (F): y = 9.000x - 1.150 (where x is 0.15 ≤ x ≤ 0.16), Formula (G): y = 6.000x - 0.230 (where x is 0.07 ≤ x ≤ 0.10).

Furthermore, to achieve excellent brightness when fabricated into color filters, the pigment of the present invention preferably exhibits the xy chromaticity coordinate region defined by the following equations (E), (H), (I), and (J). This is represented on a chromaticity diagram as shown in equations E, H, I, and J in Figure 3. The region defined by equations E, H, I, and J is chromaticity coordinate region C. Formula (E): y = -1.333x + 0.503 (where x is 0.10 ≤ x ≤ 0.16), Formula (H): y = 7.000x - 0.830 (where x is 0.15 ≤ x ≤ 0.16), Formula (I): y = -0.286x + 0.263 (where x is 0.08 ≤ x ≤ 0.15), Formula (J): y = 6.500x - 0.280 (where x is 0.08 ≤ x ≤ 0.10).

The coating composition is 1.25 parts of resin per part of pigment, calculated by mass. The resin used to form the coating is preferably an acrylic resin, with benzyl methacrylate-methacrylic acid copolymer and dimethylaminoethyl methacrylate copolymer being particularly preferred. For example, UNIDIC ZL-295 (40% solids solution) manufactured by DIC Corporation can be used as the benzyl methacrylate-methacrylic acid copolymer. The weight-average molecular weight (Mw) of the benzyl methacrylate-methacrylic acid copolymer is, for example, 12,000 to 16,000. For example, BYK-LPN6919 (60% solids solution) manufactured by BYK-Chemie can be used as the dimethylaminoethyl methacrylate copolymer. The weight-average molecular weight (Mw) of the dimethylaminoethyl methacrylate copolymer is, for example, 7,000 to 11,000. An example of a dimethylaminoethyl methacrylate copolymer is a copolymer that is prepared by dispersing 30 g of Pigment Green 58 (e.g., Fastogen Green A110 manufactured by DIC Corporation), 22.5 g of a 40% by weight resin solution of the benzyl methacrylate-methacrylic acid copolymer (e.g., ZL-295 manufactured by DIC Corporation), 132.5 g of propylene glycol monomethyl ether acetate, and 15 g of a 60% by weight resin solution of the dimethylaminoethyl methacrylate copolymer using 460 g of 0.3-0.4 mm zirconium beads in a paint shaker for 2 hours to provide a pigment dispersion having a viscosity of 10 mPa·s or less at 25°C. The viscosity mentioned above is measured according to JIS Z8803 using a cone-plate rotational viscometer (cone-plate viscometer) (e.g., RE550L manufactured by Toki Industrial Co., Ltd.).

The coating is not particularly limited and can be formed by the following method. First, using a 0.3-0.4 mm zirconium bead, 2.48 g of zinc phthalocyanine halide pigment is dispersed with 1.24 g of BYK-LPN6919, 1.86 g of UNIDIC ZL-295, and 10.92 g of propylene glycol monomethyl ether acetate for 2 hours to prepare a pigment dispersion. To 4.0 g of the resulting pigment dispersion, 0.98 g of UNIDIC ZL-295 and 0.22 g of propylene glycol monomethyl ether acetate are added and mixed using a coating shaker to prepare a coating solution. The coating solution is then rotationally coated onto a sodium glass substrate, dried at 90°C for 3 minutes, and then heated at 230°C for 1 hour to form a coating. The chromaticity is, for example, a value measured using a spectrophotometer (U-3900) manufactured by Hitachi High-Tech Science Co., Ltd.

<Coloring Composition> The coloring composition of the present invention contains at least the aforementioned zinc phthalocyanine halide pigment and a solvent.

The coloring composition may further contain a resin for coating the zinc phthalocyanine halide pigment (coating resin). The type and content of the coating resin may be the same as those described as the coating resin contained in the pigment composition above, and the preferred embodiments are also the same.

As the solvent, an organic solvent is preferred. Examples of the organic solvent include aromatic solvents such as toluene, xylene, and methoxybenzene; acetate solvents such as ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate; propionate solvents such as ethoxyethyl propionate; alcohol solvents such as methanol and ethanol; butyl solvents, propylene glycol monomethyl ether, diethylene glycol ethyl ether, and diethylene glycol dimethyl ether. Examples of the solvents include ether solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ketone solvents such as hexane; nitride solvents such as N,N-dimethylformamide, γ-butyrolactam, N-methyl-2-pyrrolidone, aniline, and pyridine; lactone solvents such as γ-butyrolactone; and carbamates such as a mixture of methyl carbamate and ethyl carbamate in a ratio of 48:52. The organic solvent is preferably polar and water-soluble, and more preferably a propionate solvent, alcohol solvent, ether solvent, ketone solvent, nitride solvent, or lactone solvent.

The content of the solvent may be 300 parts by mass or more and 1000 parts by mass or less per 100 parts by mass of the total pigment.

If necessary, and for economic reasons, the coloring composition may further include organic pigments other than zinc phthalocyanine halides, organic dyes, or organic pigment derivatives. Examples of organic pigments include conventionally used green copper phthalocyanine halides and other green metal phthalocyanine halides. Furthermore, yellow pigments used for color matching may also be used. Examples of yellow pigments include C.I. Pigment Yellow 83, C.I. Pigment Yellow 110, C.I. Pigment Yellow 129, C.I. Pigment Yellow 138, C.I. Pigment Yellow 139, C.I. Pigment Yellow 150, C.I. Pigment Yellow 180, C.I. Pigment Yellow 185, and C.I. Pigment Yellow 231. Regarding the combined ratio of zinc phthalocyanine halide pigment and yellow pigment, for example, the yellow pigment is 1 to 400 parts by mass per 100 parts by mass of zinc phthalocyanine halide pigment. Organic pigment derivatives include, for example, derivatives of known organic pigments modified (substituted) with sulfonic acid groups, carboxyl groups, amino groups, or o-phthalimidomethyl groups. Specific examples include Solsperse (registered trademark) 5000, Solsperse 12000, and Solsperse 22000 (manufactured by Lubrizol Corporation).

The coloring composition may further contain a dispersant as an ingredient other than the above. A commonly used dispersant such as a resin having an amine value may be used. Examples of dispersants include ANTI-TERRA (registered trademark) U/U100, ANTI-TERRA 204, DISPERBYK (registered trademark) 106, DISPERBYK 108, DISPERBYK 109, DISPERBYK 112, DISPERBYK 130, DISPERBYK 140, DISPERBYK 142, DISPERBYK 145, DISPERBYK 161, DISPERBYK 162, DISPERBYK 163, DISPERBYK 164, DISPERBYK 167, DISPERBYK 168, DISPERBYK 180, DISPERBYK 182, DISPERBYK 183.DISPERBYK 184.DISPERBYK 185.DISPERBYK 2000.DISPERBYK 2001.DISPERBYK 2008.DISPERBYK 2009.DISPERBYK 2013.DISPERBYK 2022.DISPERBYK 2025.DISPERBYK 2026, DISPERBYK 2050, DISPERBYK 2055, DISPERBYK 2150, DISPERBYK 2155, DISPERBYK 2163, DISPERBYK 2164, DISPERBYK 9076, DISPERBYK 9077, BYK LPN-6919, BYK LPN-21116, BYK LPN-21324, BYK LPN-22102 (manufactured by BYK-Chemie GmbH), EFKA (registered trademark) 46, EFKA 47, EFKA 4010, EFKA 4020, EFKA 4320, EFKA 4300, EFKA 4330, EFKA 4401, EFKA 4570, EFKA 5054, EFKA 7461, EFKA 7462, EFKA 7476, EFKA 7477 (manufactured by BASF GmbH), Ajisper (registered trademark) PB814, Ajisper PB821, Ajisper PB822, Ajisper PB881 (manufactured by Ajinomoto Fine-Techno Co., Ltd.), Solsperse (registered trademark) 24000, Solsperse 28000, Solsperse 37500, Solsperse 76500 (manufactured by Lubrizol Corporation), etc. The dispersant content can be 5 parts by mass or more and 120 parts by mass or less per 100 parts by mass of the total pigment.

The coloring composition may further contain a leveling agent, a coupling agent, a cationic rosin, a surfactant, an adhesive resin, a photosensitive compound (such as a photosensitive resin), a curing resin, etc. as ingredients other than the above.

A coloring composition containing a photosensitive compound may also be referred to as a photosensitive coloring composition. Examples of the photosensitive compound include thermoplastic resins such as urethane resins, acrylic resins, polyamide resins, polyimide resins, styrene maleic acid resins, and styrene maleic anhydride resins; bifunctional monomers such as 1,6-hexanediol diacrylate, ethylene glycol diacrylate, neopentyl glycol diacrylate, triethylene glycol diacrylate, bis(acryloyloxyethoxy)bisphenol A, and 3-methylpentanediol diacrylate; and polyfunctional monomers such as trihydroxymethylpropane triacrylate, pentaerythritol triacrylate, tris(2-acryloyloxyethyl) isocyanurate, dipentaerythritol hexaacrylate, and dipentaerythritol pentaacrylate; and photopolymerizable monomers.

The photosensitive coloring composition may further contain a photopolymerization initiator. Examples of the photopolymerization initiator include acetophenone, diphenyl ketone, benzyl dimethyl ketal, benzoyl peroxide, 2-chloro-9-sulfuronium, , 1,3-bis(4'-azinophenylmethylene)-2-propane, 1,3-bis(4'-azinophenylmethylene)-2-propane-2'-sulfonic acid, 4,4'-bisazidophenylethylene-2,2'-disulfonic acid, etc.

The method for producing a photosensitive coloring composition is not particularly limited, but generally involves preparing a dispersion (coloring composition) using a zinc phthalocyanine halogenide pigment or a pigment composition containing the same, a solvent, and optionally a dispersant, and then adding a photosensitive compound to the dispersion. In this case, the photosensitive resin content can be 3 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the dispersion. The photopolymerization initiator content can be 0.05 parts by mass or more and 3 parts by mass or less per 1 part by mass of the photosensitive resin.

When using a yellow pigment for toning, for example, a dispersion can be prepared using the yellow pigment, a solvent, and, if necessary, a dispersant. The dispersion containing a zinc phthalocyanine halide pigment, the dispersion containing the yellow pigment, and a photosensitive compound can then be mixed to prepare a photosensitive coloring composition. Alternatively, a green toning composition can be prepared by adding a photosensitive compound to a dispersion containing a zinc phthalocyanine halide pigment, a yellow toning composition by adding a photosensitive compound to a dispersion containing a yellow pigment, and then mixing the green and yellow toning compositions to prepare a photosensitive coloring composition. Examples of yellow pigments used for color matching include C.I. Pigment Yellow 138, C.I. Pigment Yellow 185, C.I. Pigment Yellow 150, C.I. Pigment Yellow 129, C.I. Pigment Yellow 231, and C.I. Pigment Yellow 233.

In a green pixel, the ratio of the pigment of the present invention to the total amount of the color material constituting the green pixel is, for example, 10-90% by mass, preferably 20-80% by mass. Furthermore, the ratio of the yellow color material used for color matching to the total amount of the color material constituting the green pixel is, for example, 10-90% by mass, preferably 20-80% by mass.

<Color Filter> The color filter of the present invention has a green pixel portion containing at least halogenated zinc phthalocyanine pigment. Within the color filter, the green pixel portion converts the color of light from a light source. Typically, a color filter includes not only green pixels but also red pixels, blue pixels, and a light-shielding portion (black matrix). Within the color filter, red, green, and blue pixels are arranged repeatedly in this order, and the pixels of each color are separated by the light-shielding portion.

(Light Source) Figure 2 shows an example of the spectrum of light from a light source. Figure 2 shows the spectrum in the wavelength range of 380 to 780 nm. In the spectrum shown in Figure 2, A. LED + QD or B. LED KSF are examples of white LED light sources. These white LED light sources combine a blue LED, a red phosphor, and a green phosphor to produce white light through color mixing. The spectrum of light from the light source was measured using an Olympus microscope MX-50 and an Otsuka Electronics spectrophotometer MCPD-3000 within a measurement range of 380 to 780 nm and a measurement step of 1 nm.

In the present invention, the light source emits light with an extreme wavelength of, for example, 500-560 nm, preferably 500-540 nm, within the range of 480-580 nm. Light sources with an extreme wavelength within this range are preferred for BT2020, as light at 510-532 nm is more intense. Furthermore, the ratio of the intensity at 480 nm (I480) relative to the intensity at 532 nm (I532) is, for example, 1.1 or less, preferably 1.0 or less. Furthermore, the ratio of the intensity at 480 nm (I480) relative to the intensity at 550 nm (I550) is 0.9 or less, preferably 0.8 or less. By meeting these intensities, brightness within BT2020 can be improved.

Furthermore, in the present invention, the light from the light source has a maximum wavelength within the range of 480 to 580 nm, for example, between 500 and 560 nm, the intensity at 480 nm (I480) relative to the intensity at 532 nm (I532) is, for example, 1.1 or less, and the intensity at 480 nm (I480) relative to the intensity at 550 nm (I550) is 0.9 or less. Preferably, the light has a maximum wavelength within the range of 480 to 580 nm, between 510 and 550 nm, the intensity at 480 nm (I480) relative to the intensity at 532 nm (I532) is 0.4 or less, and the intensity at 480 nm (I480) relative to the intensity at 550 nm (I550) is 0.4 or less. The optimal light intensity is when the intensity at 480 nm (I480) relative to the intensity at 532 nm (I532) is less than 0.2, and the intensity at 480 nm (I480) relative to the intensity at 550 nm (I550) is less than 0.2.

As a light source emitting the above light, in addition to the above, for example, a white LED (light emitting diode) light source, a white organic EL light source, a white inorganic EL light source, a white quantum dot light source, etc. may be used. In the case where the light source is a white LED light source, examples of the white LED light source include: a white LED light source that obtains white light by combining a red LED, a green LED, and a blue LED and mixing the colors; a white LED light source that obtains white light by combining a blue LED, a red light-emitting phosphor, and a green light-emitting phosphor and mixing the colors; a white LED light source that obtains white light by mixing the colors of a blue LED and a YAG-based phosphor; a white LED light source that obtains white light by combining an ultraviolet LED, a red light-emitting phosphor, a green light-emitting phosphor, and a blue light-emitting phosphor and mixing the colors; a white LED light source obtained by combining a red laser; a white LED light source obtained by using quantum dot technology, etc.

Figure 2 shows an example of a spectrum of light intensity for each wavelength. Commercially available light sources include green LEDs (e.g., NSPG336CS, manufactured by Nichia Corporation), KSF LEDs (e.g., NFSW157J-HG, manufactured by Nichia Corporation), and YAG1 LEDs (e.g., NSSW410A, manufactured by Nichia Corporation).

When used with the following colored materials, the color filter of this invention can display chromaticity coordinates close to BT2020 in the CIE (International Commission on Illumination) XYZ colorimetric system when measured using the aforementioned light source: 0.140 ≤ chromaticity x ≤ 0.200, 0.600 ≤ chromaticity y ≤ 0.797. Furthermore, the XYZ colorimetric system is based on the mixing amount of the three primary colors of RGB (red/green/blue) light and is commonly used when considering the display color gamut in display devices.

Green pixels containing halogenated zinc phthalocyanine pigment can be easily formed using the aforementioned coloring composition (photosensitive coloring composition). A specific method, for example, is photoetching. In this method, the coloring composition (photosensitive coloring composition) is applied to a transparent substrate such as glass using a spin coating method, roll coating method, or inkjet method. The coated film is then exposed to ultraviolet light in a pattern through a photomask. The unexposed areas are then washed away with an organic solvent or alkaline water, resulting in a colored pattern. The method for forming the pixel portion is not particularly limited. For example, the color filter can be manufactured by forming the pattern of the pixel portion using methods such as electroplating, transfer printing, micelle electrolysis, and PVED (photovoltaic electrodeposition).

Other pixel portions (e.g., red and blue pixels) can also be formed using known pigments using the same method. Example

Hereinafter, the present invention will be described in more detail based on embodiments, but the present invention is not limited to the following embodiments.

<Synthesis of Zinc Phthalocyanine Halides> Zinc phthalocyanine halides (RP1) to (RP4) were synthesized using the methods of Synthesis Examples 1 to 4. The average number of halogen atoms in each pigment is shown in Table 1.

[Synthesis Example 1] To a 1 L flask, 190 g of sulfonyl chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 315 g of aluminum chloride (manufactured by Kanto Chemical Co., Ltd.), 43 g of sodium chloride (manufactured by Tokyo Chemical Industry Co., Ltd.), 84 g of zinc phthalocyanine (manufactured by DIC Corporation), and 185 g of bromine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were added. The temperature was raised to 55°C, and the resulting mixture was poured into water, filtered, washed with water, and dried to obtain zinc phthalocyanine halide (R1). 40 g of zinc phthalocyanine halide (R1), 400 g of crushed sodium chloride, and 63 g of 1,3-butanediol (melting point: -54°C) were added to a double-arm kneader and kneaded for 20 hours with a cooling water circulation system set to -20°C. The kneaded mixture was then poured into 2 kg of water at 80°C and stirred for 1 hour. Zinc phthalocyanine halide pigment (RP1) was then obtained by filtration, hot water washing, drying, and pulverization as a cyan blue pigment. Using a ZSX100E manufactured by Rigaku Co., Ltd., fluorescence X-ray analysis of zinc phthalocyanine halide pigment (RP1) was performed. The average number of chlorine atoms and the average number of bromine atoms per zinc atom were calculated based on the mass ratios of zinc, chlorine, and bromine atoms. Furthermore, a 1 g sample of zinc phthalocyanine halide pigment, obtained by press molding (25 mm diameter), was used as a test sample. Measurements were performed in a vacuum environment with a measurement diameter of 20 mm diameter. The results showed that the average number of halogen atoms per molecule of zinc phthalocyanine halide pigment (RP1) was 8.1, of which the average number of bromine atoms was 7.9 and the average number of chlorine atoms was 0.2.

[Synthesis Example 2] A zinc phthalocyanine halide pigment (hereinafter referred to as "zinc phthalocyanine halide pigment (RP2)") was prepared in the same manner as in Comparative Example 3 of JP-A-2016-57635. The average number of chlorine atoms and the average number of bromine atoms in zinc phthalocyanine halide pigment (RP2) were calculated in the same manner as in Synthesis Example 1. The average number of halogen atoms per molecule of zinc phthalocyanine halide pigment (RP2) was 10.0, of which the average number of bromine atoms was 6.9 and the average number of chlorine atoms was 3.1.

[Synthesis Example 3] A zinc phthalocyanine halide pigment (hereinafter referred to as "zinc phthalocyanine halide pigment (RP3)") was prepared in the same manner as in Pigment 10 of Production Example 10 in JP-A-2018-36520. The average number of chlorine atoms and the average number of bromine atoms in zinc phthalocyanine halide pigment (RP3) were calculated in the same manner as in Synthesis Example 1. The average number of halogen atoms per molecule of zinc phthalocyanine halide pigment (RP3) was 7.3, of which the average number of bromine atoms was 2.0 and the average number of chlorine atoms was 5.3.

[Synthesis Example 4] Zinc phthalocyanine halide pigment (hereinafter referred to as "Zinc phthalocyanine halide pigment (RP4)") was prepared in the same manner as in Example RP4 of International Publication No. 2020/045199 (Japanese Patent Application No. 2020-520089). The average number of chlorine atoms and the average number of bromine atoms in ZnPhthalinocyanine halide pigment (RP4) were calculated in the same manner as in Synthesis Example 1. The average number of halogen atoms per molecule of ZnPhthalinocyanine halide pigment (RP4) was 10.4, of which the average number of bromine atoms was 9.3 and the average number of chlorine atoms was 1.2.

[Table 1] Halogenated zinc phthalocyanine pigment Average atomic number Halogen atoms Bromine atom Chlorine atom Synthesis example 1 RP1 8.1 7.9 0.2 Synthesis example 2 RP2 10.0 6.9 3.1 Synthesis example 3 RP3 7.3 2.0 5.3 Synthesis example 4 RP4 10.4 9.3 1.2

Next, cyan pigment dispersions (RMG1) to (RMG4), (SMG2), and a green pigment dispersion (SMG1) were prepared using the following method. Furthermore, an evaluation composition (RCG) and a toning composition (TY) were prepared. Furthermore, evaluation compositions (RDG), (SDG), (REG), and (SEG) were prepared to evaluate the filter characteristics.

<Example 1> Using a 0.3-0.4 mm zirconium bead, 2.48 g of zinc phthalocyanine halide pigment (RP1) was dispersed with 1.24 g of BYK LPN-6919 (BYK-Chemie, trade name, solids content: 60% by mass), 1.86 g of UNIDIC ZL-295 (DIC Corporation, trade name, solids content: 40% by mass), and 10.92 g of propylene glycol monomethyl ether acetate for 2 hours using a coating oscillator manufactured by Toyo Seiki Co., Ltd., to obtain a cyan pigment dispersion (RMG1).

Comparative Examples 1-3 In the same manner as Example 1, except that zinc phthalocyanine halide pigments (RP2) to (RP4) were used instead of zinc phthalocyanine halide pigment (RP1), blue pigment dispersions (RMG2) to (RMG4) were obtained.

Comparative Example 4 A green pigment dispersion (SMG1) was obtained in the same manner as in Example 1, except that Pigment Green 7 (FASTOGEN Green S, manufactured by DIC Corporation; hereinafter also referred to as "SP1") was used instead of the zinc phthalocyanine halide pigment (RP1).

Comparative Example 5 β-zinc phthalocyanine (hereinafter referred to as "SP2") was prepared according to [Production Example 3-6] in Japanese Patent Application Laid-Open No. 2020-38368. A cyan pigment dispersion (SMG2) was obtained in the same manner as in Example 1, except that (SP2) was used instead of the halogenated zinc phthalocyanine pigment (RP1).

<Evaluation of Color Filter Characteristics> (Preparation of Evaluation Composition (RCG)) To 4.0 g of cyan pigment dispersion (RMG1), 0.98 g of UNIDIC ZL-295 (trade name, manufactured by DIC Corporation, solids content: 40% by mass) and 0.22 g of propylene glycol monomethyl ether acetate were added and mixed using a paint shaker. This yielded evaluation composition (RCG1) for evaluating the single-color chromaticity of the green pixel portion used as the color filter. Furthermore, evaluation compositions (RCG2) to (RCG4) and (SCG1) to (SCG2) were prepared in the same manner as above, except that (RMG1) was replaced with (RMG2) to (RMG4) and (SMG1) to (SMG2), respectively.

Preparation of the Tinting Composition (TY) Using a 0.3-0.4 mm zirconium bead, 1.65 g of C.I. Pigment Yellow 139 (Paliotol Yellow D1819, manufactured by BASF AG), 3.85 g of DISPERBYK-161 (manufactured by BYK-Chemie, solids content: 30% by mass), and 11.00 g of propylene glycol monomethyl ether acetate were dispersed in a paint shaker for 2 hours to obtain a yellow pigment dispersion (MY1). To 4.0 g of the yellow pigment dispersion (MY1), 0.98 g of UNIDIC ZL-295 (manufactured by DIC Corporation, trade name, solid content: 40% by mass) and 0.22 g of propylene glycol monomethyl ether acetate were added and mixed using a paint shaker to obtain a toning composition (TY1).

<Light Source> The light sources used in the embodiments and comparative examples are described below. The spectra of light sources A and B are shown in Figure 2. As described above, the color filter of the present invention can display chromaticity coordinates close to BT2020 in the CIE XYZ colorimetric system, namely, 0.140 ≤ chromaticity x ≤ 0.200, 0.600 ≤ chromaticity y ≤ 0.797. In the embodiments of the present invention, (x, y) = (0.170, 0.750) in this color gamut is set as the target chromaticity coordinates. Light Source A. LED + QD – Light source described in Figure 5(a) of the paper "Langmuir 2017, 33, 13040-13050" Light Source B. LED KSF – Model "NFSW157J-HG" manufactured by Nichia Chemical Industries, Ltd.

(For Light Source A: Preparation of Evaluation Compositions (RDG) and (SDG)) Evaluation compositions (RCG1) to (RCG4) and (SCG1) to (SCG2) were mixed with the coloring composition (TY1) to prepare evaluation compositions (RDG1) to (RDG4) and (SDG1) to (SDG2) for evaluating the performance of the green pixel portion used as a color filter. Evaluation compositions (RDG1) to (RDG4) and (SDG1) to (SDG2) were spin-coated onto a sodium glass substrate and dried at 90°C for 3 minutes to produce evaluation glass substrates with a colored film on the sodium glass substrate. Furthermore, the blending ratios of the evaluation compositions (RCG1) to (RCG4) and the coloring composition (TY1), the blending ratios of the evaluation compositions (SCG1) to (SCG2) and the coloring composition (TY1), and the coating film thickness were determined such that the coating film's chromaticity (measured using a spectrophotometer U-3900 manufactured by Hitachi High-Tech Science Co., Ltd.) was (x, y) = (0.170, 0.750) when using light source A. LED + QD. The coating film thickness was adjusted by adjusting the spin speed during the rotary coating process.

(Evaluation) The brightness Y of the coating film was measured using a spectrophotometer (U-3900) manufactured by Hitachi High-Tech Science Co., Ltd. The results are shown in Table 2.

[Table 2] light source Evaluation composition Mixing ratio (TY1:RCG) (TY1:SCG) Brightness Y Pigments used in RCG or SCG Example 1 Light source A RDG1 10:90 107.1% RP1 Comparative example 1 Light source A RDG2 11:89 100.0% RP2 Comparative example 2 Light source A RDG3 24:76 86.9% RP3 Comparative example 3 Light source A RDG4 14:86 86.7% RP4 Comparative example 4 Light source A SDG1 6:94 81.8% SP1 Comparative example 5 Light source A SDG2 31:69 75.5% SP2

(For Light Source B: Preparation of Evaluation Compositions (REG) and (SEG)) Evaluation compositions (RCG1) to (RCG4) and (SCG1) to (SCG2) were mixed with the coloring composition (TY1) to prepare evaluation compositions (REG1) to (REG4) and (SEG1) to (SEG2) for evaluating the performance of the green pixel portion used as a color filter. Evaluation compositions (REG1) to (REG4) and (SEG1) to (SEG2) were spin-coated onto a sodium glass substrate and dried at 90°C for 3 minutes to produce an evaluation glass substrate with a colored film on the sodium glass substrate. Furthermore, the blending ratios of the evaluation compositions (RCG1) to (RCG4) and the coloring composition (TY1), the blending ratios of the evaluation compositions (SCG1) to (SCG2) and the coloring composition (TY1), and the coating film thickness were determined such that the coating film's chromaticity (measured using a spectrophotometer U-3900 manufactured by Hitachi High-Tech Science Co., Ltd.) was (x, y) = (0.170, 0.750) when using light source B. LED KSF. The coating film thickness was adjusted by adjusting the spin speed during the rotary coating process.

(Evaluation) The brightness Y of the coating film was measured using a spectrophotometer (U-3900) manufactured by Hitachi High-Tech Science Co., Ltd. The results are shown in Table 3.

[Table 3] light source Evaluation composition Mixing ratio (TY1:RCG) (TY1:SCG) Brightness Y Pigments used in RCG or SCG Example 1 Light source B REG1 15:85 103.9% RP1 Comparative example 1 Light source B REG2 17:83 100.0% RP2 Comparative example 2 Light source B REG3 32:68 89.9% RP3 Comparative example 3 Light source B REG4 21:79 89.6% RP4 Comparative example 4 Light source B SEG1 12:88 89.3% SP1 Comparative example 5 Light source B SEG2 40:60 81.1% SP2

As shown in Tables 2 and 3, even when the light source was changed, Example 1 had higher brightness than Comparative Examples 1-5, confirming that zinc phthalocyanine halide pigment (RP1) was superior to zinc phthalocyanine halides (RP2)-(RP4) and (SP1)-(SP2).

<Synthesis of Zinc Phthalocyanine Halide Pigments> Zinc phthalocyanine halides (RP5) to (RP8) were synthesized using the methods described in Synthesis Examples 5 to 8. The average number of halogen atoms in each pigment is shown in Table 4.

[Synthesis Example 5] To a 1 L flask, 190 g of sulfonyl chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 315 g of aluminum chloride (manufactured by Kanto Chemical Co., Ltd.), 43 g of sodium chloride (manufactured by Tokyo Chemical Industry Co., Ltd.), 84 g of zinc phthalocyanine (manufactured by DIC Corporation), and 116 g of bromine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were added. The temperature was raised to 55°C, and the resulting mixture was poured into water, filtered, washed with water, and dried to obtain zinc phthalocyanine halide (R5). 40 g of zinc phthalocyanine halide (R5), 400 g of crushed sodium chloride, and 63 g of 1,3-butanediol (melting point: -54°C) were added to a double-arm kneader and kneaded for 20 hours with a cooling water circulation system set to -20°C. The kneaded mixture was then poured into 2 kg of water at 80°C and stirred for 1 hour. Zinc phthalocyanine halide pigment (RP5) was then obtained by filtration, hot water washing, drying, and pulverization as a cyan pigment. The average number of chlorine atoms and the average number of bromine atoms in zinc phthalocyanine halide pigment (RP5) were calculated in the same manner as in Synthesis Example 1. In zinc phthalocyanine halide pigment (RP5), the average number of halogen atoms in one molecule is 4.7, of which the average number of bromine atoms is 4.4 and the average number of chlorine atoms is 0.3.

[Synthesis Example 6] To a 1 L flask, 270 g of sulfonyl chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 315 g of aluminum chloride (manufactured by Kanto Chemical Co., Ltd.), 86 g of sodium chloride (manufactured by Tokyo Chemical Industry Co., Ltd.), 84 g of zinc phthalocyanine (manufactured by DIC Corporation), and 116 g of bromine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were added. The temperature was raised to 70°C, and the resulting mixture was poured into water, filtered, washed with water, and dried to obtain zinc phthalocyanine halide (R6). 40 g of zinc phthalocyanine halide (R6), 400 g of crushed sodium chloride, and 63 g of 1,3-butanediol (melting point: -54°C) were added to a double-arm kneader and kneaded for 20 hours with a cooling water circulation system set to -20°C. The kneaded mixture was then added to 2 kg of water at 80°C and stirred for 1 hour. Zinc phthalocyanine halide pigment (RP6) was then obtained by filtration, hot water washing, drying, and pulverization as a cyan pigment. The average number of chlorine atoms and the average number of bromine atoms in zinc phthalocyanine halide pigment (RP6) were calculated in the same manner as in Synthesis Example 1. In zinc phthalocyanine halide pigment (RP6), the average number of halogen atoms in one molecule is 5.7, of which the average number of bromine atoms is 4.2 and the average number of chlorine atoms is 1.5.

[Synthesis Example 7] To a 1 L flask, 216 g of sulfonyl chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 315 g of aluminum chloride (manufactured by Kanto Chemical Co., Ltd.), 64 g of sodium chloride (manufactured by Tokyo Chemical Industry Co., Ltd.), 84 g of zinc phthalocyanine (manufactured by DIC Corporation), and 162 g of bromine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were added. The temperature was raised to 70°C, and the resulting mixture was poured into water, filtered, washed with water, and dried to obtain zinc phthalocyanine halide (R7). 40 g of zinc phthalocyanine halide (R7), 400 g of crushed sodium chloride, and 63 g of 1,3-butanediol (melting point: -54°C) were added to a double-arm kneader and kneaded for 20 hours with a cooling water circulation system set to -20°C. The kneaded mixture was then poured into 2 kg of water at 80°C and stirred for 1 hour. Zinc phthalocyanine halide pigment (RP7) was then obtained by filtration, hot water washing, drying, and pulverization as a cyan pigment. The average number of chlorine atoms and the average number of bromine atoms in zinc phthalocyanine halide pigment (RP7) were calculated in the same manner as in Synthesis Example 1. In zinc phthalocyanine halide pigment (RP7), the average number of halogen atoms in one molecule is 6.8, of which the average number of bromine atoms is 6.1 and the average number of chlorine atoms is 0.7.

[Synthesis Example 8] To a 1 L flask, 216 g of sulfonyl chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 315 g of aluminum chloride (manufactured by Kanto Chemical Co., Ltd.), 64 g of sodium chloride (manufactured by Tokyo Chemical Industry Co., Ltd.), 84 g of zinc phthalocyanine (manufactured by DIC Corporation), and 209 g of bromine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were added. The temperature was raised to 70°C, and the resulting mixture was poured into water, filtered, washed with water, and dried to obtain zinc phthalocyanine halide (R8). 40 g of zinc phthalocyanine halide (R8), 400 g of crushed sodium chloride, and 63 g of 1,3-butanediol (melting point: -54°C) were added to a double-arm kneader and kneaded for 20 hours with a cooling water circulation system set to -20°C. The kneaded mixture was then poured into 2 kg of water at 80°C and stirred for 1 hour. Zinc phthalocyanine halide pigment (RP8) was then obtained by filtration, hot water washing, drying, and pulverization as a cyan pigment. The average number of chlorine atoms and the average number of bromine atoms in zinc phthalocyanine halide pigment (RP8) were calculated in the same manner as in Synthesis Example 1. In zinc phthalocyanine halide pigment (RP8), the average number of halogen atoms in one molecule is 8.9, of which the average number of bromine atoms is 8.4 and the average number of chlorine atoms is 0.5.

[Table 4] Halogenated zinc phthalocyanine pigment Average atomic number Halogen atoms Bromine atom Chlorine atom Synthesis example 5 RP5 4.7 4.4 0.3 Synthesis example 6 RP6 5.7 4.2 1.5 Synthesis Example 7 RP7 6.8 6.1 0.7 Synthesis example 8 RP8 9.9 9.4 0.5

<Examples 2-6> In the same manner as Example 1, except that zinc phthalocyanine halide pigments (RP5) to (RP8) were used instead of zinc phthalocyanine halide pigment (RP1), blue pigment dispersions (RMG5) to (RMG8) were obtained.

<Evaluation of Color Filter Characteristics> (Preparation of Evaluation Composition (RCG)) To 4.0 g of cyan pigment dispersion (RMG5), 0.98 g of UNIDIC ZL-295 (trade name, manufactured by DIC Corporation, solids content: 40% by mass) and 0.22 g of propylene glycol monomethyl ether acetate were added and mixed using a paint shaker. This yielded evaluation composition (RCG5) for evaluating the performance of the green pixel portion of the color filter. Evaluation compositions (RCG6) to (RCG8) were prepared in the same manner as above, except that (RMG5) was replaced with (RMG6) to (RMG8).

(Preparation of the Tinting Composition (TY)) Using a 0.3-0.4 mm zirconium bead, 1.65 g of C.I. Pigment Yellow 185 (Paliotol Yellow D1155, manufactured by BASF AG), 3.85 g of DISPERBYK-161 (manufactured by BYK-Chemie, solids content: 30% by mass), and 11.00 g of propylene glycol monomethyl ether acetate were dispersed in a paint shaker for 2 hours to obtain a yellow pigment dispersion (MY2). To 4.0 g of the yellow pigment dispersion (MY2), 0.98 g of UNIDIC ZL-295 (trade name, manufactured by DIC Corporation, solids content: 40% by mass) and 0.22 g of propylene glycol monomethyl ether acetate were added and mixed using a paint shaker to obtain a toning composition (TY2). Furthermore, an evaluation composition (TY3) was prepared in the same manner as above, except that C.I. Pigment Yellow 138 (Paliotol Yellow K0961HD, manufactured by BASF Corporation) was used instead of C.I. Pigment Yellow 185. Furthermore, an evaluation composition (TY4) was prepared in the same manner as above, except that the quinoline yellow compound (D) described in the examples of International Publication No. 2018/159372 (Japanese Patent Application No. 2018-560690) was used instead of C.I. Pigment Yellow 185.

(For Light Source A: Preparation of Evaluation Composition (RFG)) Evaluation compositions (RCG1)-(RCG2) and (RCG5)-(RCG8) were mixed with the coloring composition (TY2) to prepare evaluation compositions (RFG1)-(RFG2) and (RFG5)-(RFG8) for evaluating the performance of the green pixel portion used as a color filter. Evaluation compositions (RFG1)-(RFG2) and (RFG5)-(RFG8) were spin-coated onto a sodium glass substrate and dried at 90°C for 3 minutes to produce evaluation glass substrates with a colored film on the sodium glass substrate. Furthermore, the blending ratios of the evaluation compositions (RFG1) to (RFG2) and the coloring composition (TY2), the blending ratios of the evaluation compositions (RFG5) to (RFG8) and the coloring composition (TY2), and the coating film thickness were determined such that the coating film's chromaticity (measured using a spectrophotometer U-3900 manufactured by Hitachi High-Tech Science Co., Ltd.) was (x, y) = (0.170, 0.750) when using light source A. LED + QD. The coating film thickness was adjusted by adjusting the spin speed during the spin coating process.

(Evaluation) The brightness Y of the coating film was measured using a spectrophotometer (U-3900) manufactured by Hitachi High-Tech Science Co., Ltd. The results are shown in Table 5.

[Table 5] light source Evaluation composition Mixing ratio (TY2:RCG) Brightness Y Pigments used in RCG Example 2 Light source A RFG1 11:89 106.5% RP1 Example 3 Light source A RFG5 23:77 112.4% RP5 Example 4 Light source A RFG6 18:82 112.8% RP6 Example 5 Light source A RFG7 14:86 111.1% RP7 Example 6 Light source A RFG8 10:90 104.6% RP8 Comparative example 6 Light source A RFG2 12:88 100.0% RP2

(For Light Source A: Preparation of Evaluation Composition (RGG)) Evaluation compositions (RCG1)-(RCG2) and (RCG5)-(RCG8) were mixed with coloring composition (TY3) to prepare evaluation compositions (RGG1)-(RGG2) and (RGG5)-(RGG8) for evaluating the performance of the green pixel portion used as a color filter. Evaluation compositions (RGG1)-(RGG2) and (RGG5)-(RGG8) were spin-coated onto a sodium glass substrate and dried at 90°C for 3 minutes to produce evaluation glass substrates with a colored film on the sodium glass substrate. Furthermore, the blending ratios of evaluation compositions (RGG1) to (RGG2) and coloring composition (TY3), the blending ratios of evaluation compositions (RGG5) to (RGG8) and coloring composition (TY3), and the coating film thickness were determined such that the coating film's chromaticity (measured using a Hitachi High-Tech Science U-3900 spectrophotometer) was (x, y) = (0.170, 0.750) when using light source A. LED + QD. The coating film thickness was adjusted by adjusting the spin speed during the spin coating process.

(Evaluation) The brightness Y of the coating film was measured using a spectrophotometer (U-3900) manufactured by Hitachi High-Tech Science Co., Ltd. The results are shown in Table 6.

[Table 6] light source Evaluation composition Mixing ratio (TY3:RCG) Brightness Y Pigments used in RCG Example 2 Light source A RGG1 41:59 106.0% RP1 Example 3 Light source A RGG5 59:41 114.8% RP5 Example 4 Light source A RGG6 52:48 114.8% RP6 Example 5 Light source A RGG7 46:54 112.2% RP7 Example 6 Light source A RGG8 39:61 104.1% RP8 Comparative example 6 Light source A RGG2 43:57 100.0% RP2

(For Light Source A: Preparation of Evaluation Composition (RHG)) Evaluation compositions (RCG1)-(RCG2) and (RCG5)-(RCG8) were mixed with coloring composition (TY4) to prepare evaluation compositions (RHG1)-(RHG2) and (RHG5)-(RHG8) for evaluating the performance of the green pixel portion used as a color filter. Evaluation compositions (RHG1)-(RHG2) and (RHG5)-(RHG8) were spin-coated onto a sodium glass substrate and dried at 90°C for 3 minutes to produce evaluation glass substrates with a colored film on the sodium glass substrate. Furthermore, the blending ratios of evaluation compositions (RHG1) to (RHG2) and coloring composition (TY4), the blending ratios of evaluation compositions (RHG5) to (RHG8) and coloring composition (TY4), and the coating film thickness were determined such that the coating film's chromaticity (measured using a spectrophotometer U-3900 manufactured by Hitachi High-Tech Science Co., Ltd.) was (x, y) = (0.170, 0.750) when using light source A. LED + QD. The coating film thickness was adjusted by adjusting the spin speed during the spin coating process.

(Evaluation) The brightness Y of the coating film was measured using a spectrophotometer (U-3900) manufactured by Hitachi High-Tech Science Co., Ltd. The results are shown in Table 7.

[Table 7] light source Evaluation composition Blending ratio (TY4:RCG) Brightness Y Pigments used in RCG Example 2 Light source A RHG1 13:87 106.4% RP1 Example 3 Light source A RHG5 26:74 113.0% RP5 Example 4 Light source A RHG6 21:79 113.2% RP6 Example 5 Light source A RHG7 17:83 111.4% RP7 Example 6 Light source A RHG8 13:87 104.4% RP8 Comparative example 6 Light source A RHG2 15:85 100.0% RP2

As shown in Tables 5-7, even when the yellow pigment used for color matching was changed, Examples 2-6 showed higher brightness than Comparative Example 6, confirming that zinc phthalocyanine halide pigments (RP1) and (RP5)-(RP8) were superior to zinc phthalocyanine halide pigment (RP2).

<Reference Examples 1-8> <Color Evaluation of Color Filters> (Evaluation Substrate Preparation) Evaluation compositions (RCG1)-(RCG8) and (SCG2) were spin-coated onto sodium glass substrates, dried at 90°C for 3 minutes, and then heated at 230°C for 1 hour. These evaluation glass substrates had a colored film on the sodium glass substrate. Furthermore, by adjusting the spin speed during spin coating, the thickness of the colored film obtained by heating at 230°C for 1 hour was adjusted. For each reference example, evaluation glass substrates with a colored film thickness of 1.5 μm, 1.9 μm, and 2.4 μm were produced. The film thickness was measured using a white interference microscope (VS1330) manufactured by Hitachi High-Tech Science Co., Ltd.

(Evaluation) The chromaticity (x, y) of the colored film was measured for each evaluation glass substrate under illuminant C using a spectrophotometer (U-3900) manufactured by Hitachi High-Tech Science Co., Ltd. The results are shown in Table 8. Furthermore, as shown in Figure 3, the obtained chromaticity (x, y) of the colored film was plotted on the xy chromaticity coordinates of the CIE XYZ color system. Furthermore, Figure 3 shows the chromaticity coordinate region A defined by the following equations (A) to (D), the xy chromaticity coordinate region B defined by the following equations (C) and (E) to (G), and the xy chromaticity coordinate region C defined by the following equations (E) and (H) to (J). The three markers for RCG1, 5-8, RCG2-4, and SCG2 in Figure 3 represent the coordinates when the film thickness is 1.5, 1.9, and 2.4 μm, respectively. Formula (A): y = -1.766x + 0.618 (where x is 0.10 ≤ x ≤ 0.17), Formula (B): y = 5.889x - 0.683 (where x is 0.15 ≤ x ≤ 0.17), Formula (C): y = 0.125x + 0.181 (where x is 0.07 ≤ x ≤ 0.15), Formula (D): y = 8.380x - 0.397 (where x is 0.07 ≤ x ≤ 0.10), Formula (E): y = -1.333x + 0.503 (where x is 0.10 ≤ x ≤ 0.16), Formula (F): y = 9.000x - 1.150 (where x is 0.15 ≤ x ≤ 0.16), Formula (G): y = 6.000x - 0.230 (where x is 0.07 ≤ x ≤ 0.10), Formula (H): y = 7.000x - 0.830 (where x is 0.15 ≤ x ≤ 0.16), Formula (I): y = -0.286x + 0.263 (where x is 0.08 ≤ x ≤ 0.15), Formula (J): y = 6.500x - 0.280 (where x is 0.08 ≤ x ≤ 0.10).

[Table 8] pigments Evaluation composition Film thickness 1.5 μm Film thickness 1.9 μm Film thickness 2.4 μm Chroma x Chroma y Chroma x Chroma y Chroma x Chroma y Reference Example 1 RP1 RCG1 0.1212 0.3472 0.1182 0.3509 0.1146 0.3555 Reference Example 2 RP2 RCG2 0.1266 0.3426 0.1229 0.3458 0.1184 0.3499 Reference Example 3 RP3 RCG3 0.1323 0.2277 0.1287 0.2225 0.1241 0.2160 Reference Example 4 RP4 RCG4 0.1608 0.3745 0.1549 0.3839 0.1475 0.3957 Reference Example 5 RP5 RCG5 0.1235 0.2563 0.1086 0.2525 0.0900 0.2476 Reference Example 6 RP6 RCG6 0.1293 0.2606 0.1260 0.2610 0.1219 0.2614 Reference Example 7 RP7 RCG7 0.1164 0.2868 0.1147 0.2883 0.1125 0.2901 Reference Example 8 RP8 RCG8 0.1418 0.3557 0.1289 0.3694 0.1128 0.3865 Reference Example 9 SP2 SCG2 0.1297 0.2091 0.1252 0.2014 0.1197 0.1918

In Table 8 above, (RP1), (RP5)-(RP8) used in Reference Examples 1, 5-8 are pigments of the present invention (Examples). On the other hand, RP4 and SP2 used in Reference Examples 4 and 9 are pigments outside the scope of the present invention (Comparative Examples). As shown in Figure 3, (RCG1), (RCG5)-(RCG8) exhibit the xy chromaticity coordinate region defined by equations (A)-(D) in the CIE XYZ colorimetric system when colorimetry is performed using only illuminant C, with a film thickness of 1.5 μm to 2.4 μm and a composition of 1.25 parts resin per part pigment, calculated on a mass basis. Based on the above results, it can be confirmed that the average number of halogen atoms in a molecule is greater than 0.2 and less than 10, the average number of bromine atoms is greater than 0.1 and less than 10, and the average number of chlorine atoms is greater than 0.1 and less than 2. Consequently, zinc phthalocyanine halides whose hue falls within the range of equations (A) to (D) have higher brightness.

without

Figure 1 shows a color gamut close to BT2020 on an xy chromaticity diagram. Figure 2 shows an example of the spectrum of light from a light source. Figure 3 shows a reference example pigment on a monochromatic chromaticity diagram (x-axis: chromaticity x, y-axis: chromaticity y).

Claims (3)

A color filter pigment is used to form a coating in the green pixel portion of a color filter. When the coating has a film thickness of 1.5 μm to 2.4 μm and a composition of 1.25 parts of resin per part of the pigment, the pigment exhibits the xy chromaticity coordinate region defined by the following equations (A) to (D) in the CIE XYZ colorimetric system when colorimetry is performed using only a C illuminant: Equation (A) y = -1.766x + 0.618 (where x is 0.10 ≤ x ≤ 0.17), Equation (B) y = 5.889x - 0.683 (where x is 0.15 ≤ x ≤ 0.17), and Equation (C) y=0.125x+0.181 (wherein x is 0.07≦x≦0.15), Formula (D) y=8.380x-0.397 (wherein x is 0.07≦x≦0.10), and the pigment comprises a compound represented by the following formula (1), namely, a halogenated zinc phthalocyanine pigment, wherein the average number of halogen atoms in one molecule of the compound is 0.2 or more and 10 or less, the average number of bromine atoms in one molecule of the compound is 0.1 or more and 10 or less, and the average number of chlorine atoms in one molecule of the compound is 0.1 or more and less than 2, [In formula (1), X ¹ to X ¹⁶ each independently represent a hydrogen atom or a halogen atom]. A coloring composition comprising the color filter pigment of claim 1 and a solvent. A color filter having a coating film formed of the color filter pigment of claim 1 in a green pixel portion.