METHOD FOR PRODUCING alpha-TYPE CRYSTAL TRANSFORMATION DICHLORODIKETOPYRROLOPYRROLE PIGMENT, alpha-TYPE CRYSTAL TRANSFORMATION DICHLORODIKETOPYRROLOPYRROLE PIGMENT, AND COLORED COMPOSITION PREPARED BY USING THE PIGMENT

摘要

PROBLEM TO BE SOLVED: To provide a dichlorodiketopyrrolopyrrole pigment which has a crystal transformation of anα-type and which is of fine and sized particles. SOLUTION: Anα-type crystal transformation dichlorodiketopyrrolopyrrole pigment is produced by wet grinding a crude dichlorodiketopyrrolopyrrole pigment, in which a mixture ofα-type crystal transformation andβ-type crystal transformation exists, in the presence of a grinding material and a wetting agent. Since thus produced pigment is fine and sized particles, it can be used preferably as a pigment for a color filter etc. COPYRIGHT: (C)2008,JPO&INPIT