Dic Corporation

Yukiko Higuchi

Shingo Saitou

Hideki Okabe

Hidehiro Ootake

Hiromasa Kikuchi

Shogo Yamada

Kentarou Matsumura

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 2θ of 14.8±0.2° to a diffraction peak intensity at a diffraction angle 2θ of 11.9±0.2° is 1.20 or less, as measured by X-ray diffractometry with respect to the quinacridone solid solution pigment.

Solid solution of quinacridone and ink composition containing same

A technical problem of the present invention is to provide a condensed polycyclic organic pigment having excellent dispersion properties and dispersion stability. More specifically, the technical problem of the present invention is to provide a condensed polycyclic organic pigment in which a practically sufficient viscosity is achieved in terms of both the initial viscosity of a base ink and the viscosity over time of a base ink when used in the printing ink application. As a result of thorough studies on the surface state of organic pigment particles and interaction among components constituting a printing ink, it has been found that the technical problem can be solved by using a polyvalent metal inorganic salt in a condensed polycyclic organic pigment, thus accomplishing the present invention.

Condensed polycyclic organic pigment composition containing polyvalent metal inorganic salt

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.

Quinacridone pigment composition for coloring resins

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.

Growing community of inventors

Kamisu, Japan

Yukiko Higuchi