A method for producing a halogenated organic pigment comprising a halogenation step of halogenating an organic pigment with a halogenating agent, wherein the halogenating agent comprises one or more N-haloimide compounds selected from the group consisting of trichloroisocyanuric acid, a metal salt of dichloroisocyanuric acid, tribromoisocyanuric acid, and a metal salt of dibromoisocyanuric acid. According to the present invention, a method for producing a halogenated organic pigment which does not use high toxic raw materials, does not generate a large amount of unfavorable by-products such as hydrogen halide gas and succinimide, and is excellent in terms of safety and productivity can be provided.

Provided is a quinacridone pigment composition for coloring plastics, particularly engineering plastics. The quinacridone pigment composition has high transparency and high color strength and also has high heat resistance, so that discoloration during molding of a resin (a color change of a molded plate) is very small. Also provided are a masterbatch and a resin molded product that contain the pigment composition. The pigment composition for coloring resins contains a quinacridone pigment and a pigment that absorbs fluorescence in a wavelength range of 500 to 600 nm. The inventors have found that, when the pigment composition is used as a colorant of a resin molded product subjected to a high-temperature thermal history, the change in color, i.e., the discoloration, of the resin molded product obtained is very small. Thus, the present invention has been completed.

Provided is a quinacridone pigment composition for coloring plastics, particularly engineering plastics. The quinacridone pigment composition has high transparency and high color strength and also has high heat resistance, so that discoloration during molding of a resin (a color change of a molded plate) is very small. Also provided are a masterbatch and a resin molded product that contain the pigment composition. The pigment composition for coloring resins contains a quinacridone pigment and a pigment that absorbs fluorescence in a wavelength range of 500 to 600 nm. The inventors have found that, when the pigment composition is used as a colorant of a resin molded product subjected to a high-temperature thermal history, the change in color, i.e., the discoloration, of the resin molded product obtained is very small. Thus, the present invention has been completed.

A photoelectric conversion element according to an embodiment of the present disclosure includes: a first electrode 15a and a second electrode 18 facing each other; and a photoelectric conversion layer 17 provided between the first electrode 15a and the second electrode 18, and including a first quinacridone derivative represented by a formula (1).

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An aqueous organic pigment dispersion contains a green copper phthalocyanine pigment and an azo-coupled -ketoamide pigment. It also includes an organic pigment dispersant at 40 weight % to 100 weight %, based on the sum of the weights of the organic pigments. This aqueous organic pigment dispersion can be combined with a humectant to provide an aqueous green inkjet ink composition. The weight ratio of the green copper phthalocyanine pigment to the azo-coupled -ketoamide pigment is from 1:1 to 10:1. The median particle diameter of each of the green copper phthalocyanine pigment and the azo-coupled -ketoamide pigment is less than 85 nm. At least 95% of the total particles of each of the green copper phthalocyanine pigment and the azo-coupled -ketoamide pigment have a particle diameter of less than 150 nm. The aqueous green inkjet ink compositions can be used in various inkjet printing methods.

An aqueous organic pigment dispersion contains a green copper phthalocyanine pigment and an azo-coupled -ketoamide pigment. It also includes an organic pigment dispersant at 40 weight % to 100 weight %, based on the sum of the weights of the organic pigments. The weight ratio of the green copper phthalocyanine pigment to the azo-coupled -ketoamide pigment is from 1:1 to 10:1. The median particle diameter of each of the green copper phthalocyanine pigment and the azo-coupled -ketoamide pigment is less than 85 nm. At least 95% of the total particles of each of the green copper phthalocyanine pigment and the azo-coupled -ketoamide pigment have a particle diameter of less than 150 nm. This dispersion can be used to prepare aqueous green inkjet ink compositions that can be used in various inkjet printing methods.

An object to be achieved by the present, invention is to provide a quinacridone pigment having hue that is yellowish and clear and having excellent storage stability, wherein the quinacridone pigment can be advantageously used in an ink-jet ink and the like. Provided is a quinacridone solid solution pigment comprising at least C. I. Pigment Violet 19 and C. I. Pigment Red 122, wherein the ratio of a diffraction peak intensity at a diffraction angle 2? of 14.8?0.2? to a diffraction peak intensity at a diffraction angle 2? of 11.9?0.2? is 1.20 or less, as measured by X-ray diffractometry with respect to the quinacridone solid solution pigment.

An object to be achieved by the present, invention is to provide a quinacridone pigment having hue that is yellowish and clear and having excellent storage stability, wherein the quinacridone pigment can be advantageously used in an ink-jet ink and the like. Provided is a quinacridone solid solution pigment comprising at least C. I. Pigment Violet 19 and C. I. Pigment Red 122, wherein the ratio of a diffraction peak intensity at a diffraction angle 2? of 14.8?0.2? to a diffraction peak intensity at a diffraction angle 2? of 11.9?0.2? is 1.20 or less, as measured by X-ray diffractometry with respect to the quinacridone solid solution pigment.

A nano-composite structure. A synthetic nano-composite is described having a first component including a fibrous structured amorphous silica structure, and a second component including a precipitated calcium carbonate structure developed by pressure carbonation. The nano-composite may be useful for fillers in paints and coatings. Also, the nano-composite may be useful in coatings used in the manufacture of paper products.

A process for the production of a quinacridone pigment composition is provided. For use in environmentally friendly inks, the pigment composition offers high chroma, high color strength, and high dispersion stability. Also provided is a water- or alcohol-based environmentally friendly ink that contains a quinacridone pigment composition obtained through this process. According to the inventors' research, adding a quinacridone derivative to a quinacridone solid solution in two different steps in a process, during and after treatment for the control of crystals, gives the resulting pigment composition the color characteristics of high color strength and high chroma, as well as high dispersion stability. The present invention is based on these findings.