They are used for coloring synthetics, plastics, gasoline, oils, and waxes. The dyes are
predominantly azo and anthraquinone, but phthalocyanine and triarylmethane
dyes are also used. Perchloroethylene is the preferred
solvent.
These dyes are water-insoluble but soluble in alcohols,
chlorinated hydrocarbons, or liquid ammonia.
