| 摘要 |
<p>The present invention relates to C. I. Pigment Red 254 for coloring, which can color an object to be colored so as to have a higher chroma than that with conventional technology and a production method for easily producing it. For the purpose, the inventors provide the production method for the pigment, wherein the intersection of mass tone ”H * and ”C * of a color coating film in an acrylic-melamine coating test is, on X-Y coordinate plane to which the ”H * is defined as the X-axis and the ”C * is defined as the Y-axis, within the surrounded region determined by specific three equations; and a production method for the pigment provides the production method of the pigment, including a process of heating crude pigment at 100-130 °C for 2 - 10 hours in an aprotic polar organic solvent which is strongly alkaline, which comprises the step of, prior to the heating process, beforehand, heating at 100-130 °C in neutral or weaker alkaline aprotic polar organic solvent, the mean particle diameter is finally larger than the mean particle diameter before heating.</p> |
