Dic Corporation

Kengo Yasui

Kozue Sunouchi

Hitoshi Kondo

Kazuhiro Sugiyama

Tatsuya Shigehiro

Ryuji Yokoyama

Takao Ogihara

Yuuya Enomoto

Tadashi Matsumoto

A new yellow pigment excellent in both brightness and coloring power is provided. It has been found that dimerization of a specific quinophthalone skeleton gives more selective absorption and transmittance. Furthermore, the dimerization method was also studied, and it has been found that excessive reddish tone can be suppressed by cleaving the conjugate using a methylene chain as a spacer instead of simply employing a direct bond. In addition, dispersibility has been improved by polyhalogenation and introduction of an imide structure. Furthermore, a coloring agent containing the quinophthalone compound and a coloring composition containing the coloring agent are provided.

Quinophthalone compound

Provided are a quinacridone pigment having a low content of a primary aromatic amine, a method for producing the same, and also a gravure and flexo ink, a colorant for plastic, a paint, a lithographic ink, a toner, or an ink-jet ink using the pigment. The quinacridone pigment having a low primary aromatic amine content is provided by washing a quinacridone pigment with at least one solvent selected from water and an organic solvent, or by adding an oxidizing agent to a pigment slurry including a quinacridone pigment and at least one solvent selected from water and an organic solvent to oxidatively decompose the aromatic amine.

Quinacridone pigment of low amine content and method for producing same

An aqueous pigment dispersion used for preparing an ink jet recording aqueous ink comprises an anionic group-containing organic polymeric compound, an organic pigment, an organic pigment derivative, and the water, wherein the polymeric compound, the organic pigment, and the organic pigment derivative are dispersed in water, the organic pigment and the organic pigment derivative are a diketopyrrolopyrrole-based red pigment and a phthalimidoalkylated quinacridone, respectively, and the phthalimidoalkylated quinacridone content is in the range of 1.6 to 3.8% relative to the total (100%) of the diketopyrrolopyrrole-based red pigment and the phthalimidoalkylated quinacridone on a mass basis. Furthermore, there is provided an ink jet recording aqueous ink containing such an aqueous pigment dispersion, wherein the aqueous pigment dispersion is diluted such that the total of the organic pigment content and the organic pigment derivative content is from 1 to 8% on a mass basis.

Aqueous pigment dispersion used for preparing ink jet recording aqueous ink, and ink jet recording aqueous ink

An aqueous pigment dispersion capable of easily preparing an aqueous pigment ink for inkjet recording, from which is obtained a colored image which is excellent in scratch fastness and excellent in properties on any recording media such as color development on plain papers and gloss on dedicated papers, is provided. An aqueous pigment dispersion containing carbon black or an organic pigment (P), a (meth)acrylic copolymer (A), a polyoxyethylene/polyoxypropylene block copolymer (B) represented by the following general formula (1), a polyether based polyurethane (C), a basic material and water, wherein a mass ratio of the total of nonvolatile contents of (A), (B) and (C) to (P), (A+B+C)/P, is from 0.3 to 1.6; and a mass ratio of A/(A+B+C) is from 0.05 to 0.45, is provided.HO&#x2014;(CHO)&#x2014;(CHO)&#x2014;(CHO)&#x2014;H&#x2003;&#x2003;(General Formula 1)

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Kengo Yasui