| 摘要 |
PROBLEM TO BE SOLVED: To provide a production method for a fine quinacridone pigment with excellent transparency being more fine as compared with the conventional quinacridone pigment, having a larger specific surface area and having a more excellent coloring force when it is mixed with a medium to be colored. SOLUTION: In the production method for the fine quinacridone pigment, the quinacridone crude pigment is precipitated by hydrolyzing a poly-phosphoric acid solution containing 23-30 mass% of the quinacridone compound and subsequently the obtained quinacridone crude pigment is subjected to heat treatment in a polar aprotic solvent in the absence of a crushing medium. COPYRIGHT: (C)2007,JPO&INPIT
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