Dic Corporation

Hideki Okabe

Yukiko Higuchi

Shingo Saitou

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

Sakura, Japan

Hideki Okabe