Vat Dyes Prepared as Pigments

In this section a number of polycyclic pigments are discussed which have been used for a long time as vat dyes for textile fibers. Heading the list are perylene, perinone, and thioindigo pigments, as well as pigments derived from anthraquinone. 

The polycyclic colorants which are discussed in this context (and this is also true for copper phthalocyanine and quinacridone pigments) as a rule evolve from the manufacturing process as products with relatively coarse particles, which is in contrast to azo pigments (Sec. 2.2.3). 

Various methods of aftertreatment have been developed to transform vat dyes into easily dispersible pigments. Heading the list are the following methods  

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