| 摘要 |
Pigmentary grade quinacridone pigments are prepared from crude quinacridone by conversion to aggregated low crystallinity quinacridones followed by milling the aggregated low crystallinity quinacridone in the presence of a liquid which wets the pigment and can improve the crystallinity of quinacridone at 10 DEG to 60 DEG C. Suitable quinacridones include <IMAGE> <IMAGE> and mixtures thereof with up to 15 wt. % of <IMAGE> where R1, R2, R3, R4, R5 R6 are hydrogen, fluorine, chlorine, bromine, methyl or methoxy; R7, R9 and R10 are hydrogen or chlorine; and R8 is hydrogen, chlorine, bromine, nitro, alkyl groups of 1 to 5 carbon atoms, alkoxy groups of 1 or 2 carbon atoms or benzoylamino, and m is an integer of from 1 to 4. |
