Heat-resisting Organic Pigments.

Heat-resistant organic pigments are particularly required for coloring HDPE and PP. Depending on the type of finished article, processing temperatures of up to 300 degree C are required. So far, cadmium pigments have been predominantly used in such cases. Since this class of pigments has been banned, e. g. in Sweden, the use of organic pigments without heavy metals has become necessary. Data are given on the physical properties and heat resistance of two azodyes.