An ink jet ink composition includes: a colorant including a compound (A) represented by formula (1) below; an anionic dispersant; water; a surfactant; and a water-soluble organic solvent. In high-performance liquid chromatography (HPLC) analysis of the colorant at a measurement wavelength of 500 nm, the peak area of a compound (B) represented by formula (2) is 1.4% or less based on 100% of the total peak area of the colorant, and the peak area of a compound (C) represented by formula (3) is 0.8% or less based on 100% of the total peak area of the colorant. The water-soluble organic solvent includes a glycerol and a glycol.

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The present invention provides an aqueous pigment dispersion including a pigment, an anionic group-containing organic polymer compound, and bio-nanofibers having an average diameter of 1 nm or more and 100 nm or less and an aspect ratio of 100 or more, and also provides an aqueous ink using the aqueous pigment dispersion. The bio-nanofibers are preferably cellulose nanofibers or chitosan nanofibers. The anionic group-containing organic polymer compound is preferably at least one selected from the group consisting of acrylic resins having anionic groups, polyurethane resins having anionic groups, and polysaccharide derivatives having anionic groups.

Provided herein are hybrid pigments and methods of making the same. The hybrid pigments include a natural polyamide substrate and an acid dye disposed on the natural polyamide substrate. The hybrid pigments are biodegradable, compostable, or both, and provide an environmentally friendly alternative to synthetic polymer particle-based pigments.

The present invention relates to [1] a process for producing a pigment composition, including the step of subjecting a raw material pigment composition containing PY74 and a specific by-product to a treatment with an oxidizing agent, in which a content of the specific by-product in the pigment composition after the treatment on the basis of a content of PY74 in the pigment composition after the treatment is not more than 1,200 mg/kg; [2] a process for producing a pigment composition, including the step of subjecting a raw material pigment composition containing PY74, a specific by-product and water to a treatment with hydrogen peroxide; [3] a method of reducing a content of a specific by-product in a raw material pigment composition containing PY74 and the specific by-product, said method including the step of subjecting the raw material pigment composition to a treatment with an oxidizing agent; and [4] a method of preventing an ink for ink-jet printing from suffering from ejection defects, including the step of compounding the pigment composition produced by any of the aforementioned processes in the ink for ink-jet printing.

The present invention relates to a colouring composition to be used in the manufacture of food and pharmaceutical products.

The present invention relates to [1] a process for producing a pigment composition, including the step of subjecting a raw material pigment composition containing C.I. Pigment Yellow 74, a specific by-product and water to heat treatment at a temperature of from 160 to 210 C.; and [2] a method of reducing a content of a by-product in a raw material pigment composition containing C.I. Pigment Yellow 74, the specific by-product and water, said method including the step of subjecting the raw material pigment composition to heat treatment at a temperature of from 160 to 210 C.

Radiation-curable compositions of Pigment Violet 23 are described which can be used advantageously in UV inks for inkjet printing machines. Soiling containing such UV inks, especially within inkjet printing machines, can be removed particularly easily in a contactless procedure with conventional cleaners. The radiation-curable compositions described contain at least one modified Pigment Violet 23 which carries at least one polar functional group of the formula (I):
X-E (I) where X is a bridging group and E is a polar molecule radical.

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.

Provided is a pigment composition that includes an isoindoline compound, has excellent dispersibility, weather resistance and heat resistance, and good storage stability, and is capable of forming images having high chroma and the like, the pigment composition including an isoindoline compound represented by formula (1) and an isoindoline compound represented by formula (2). Also provided are a colorant composition, a coating material, an ink, an ink set, a printed matter, and a packaging material.

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An object of the present invention is to provide a technique of suppressing precipitation of an anthocyanin pigment in a range other than the highly acidic range.

The present invention provides an anthocyanin pigment preparation, comprising: an anthocyanin pigment; and an emulsifier, wherein the pH when the anthocyanin pigment preparation is diluted with water or dissolved in water so that a color value becomes 10 is more than 3.