Pigments bleeding characteristics

Their solvent stability is poor, it approaches that of the above-mentioned yellows (Sec. 2.3.3). Migration characteristics, i.e., fastness to bleeding and blooming, are consequently inferior, although the pigments are generally resistant to alkali and acid. 

Benzimidazolone pigments, especially those covering the red range of the spectrum, were originally developed and used mostly for plastics. None of them were found to adversely affect the physical characteristics of their host medium. Benzimidazolone pigments do not bloom in plasticized PVC and other polymers. They are usually bleed resistant under typical application conditions. 

As part of a general program to improve performance characteristics of the traditional carbazole dioxazine pigment in such areas as bleed resistance, solvent fastness and heat stability, and at the same time to extend the range of shades beyond violet, a new class of dioxazine pigment bearing quinoxalinedione and benzimidazo-lone moieties in place of carbazole residue has been developed at Clariant (Figure 20-14). By simple manipulation of the substituents on the heterocyclic... 

Pigments used for PO fibers must have some technical characteristics, such as efficient thermal stability light fastness adequate for the intended uses of the finished articles no migration (blooming nor contact bleed) compatibility with other additives (stabilizers, etc.) and lack of photodestructive effect on polymer and lack of negative influence on the fiber s mechanical properties. 

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