Disazo diarylide yellow pigments

Disazo condensation pigments, whose manufacture is somewhat more demanding than that of diarylide yellow and Naphthol AS pigments, are correspondingly expensive. 

Diarylide Yellows. Diarylide or disazo yellow pigments are represented by the following general structural formula ... 

Benzidine yellow n. Benzidine or diarylide yellows are disazo pigment dyestuffs. They are approximately twice as strong, much more bleed and heat resistant and markedly inferior in lightfastness versus Hansa yellows. 

Disazo Y0IIOW and R d. Diarylide yellows use dichlorobenzidine (DCB) as a difunctional amine. The coupler changes, as can be seen by the generic name AAOT, AAMX, AAA, etc hence it is the coupler that imparts the differences seen in the pigment (see Fig. 4). 

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