Monoazo Yellow and Orange Pigments

Most non-laked monoazo yellow and orange pigments are derivatives of the following structure ... 

Monoazo yellow and orange pigments are easily dispersed in most media. Aided by a dissolver, a number of types can even be worked into long-chain alkyd resin systems. 

Strong migration tendencies practically exclude monoazo yellow and orange pigments from being used for the mass coloration of plastics they bleed and bloom considerably in most polymer systems. Again, Pigment Yellow 97 is an exception... 

Commercially Available Monoazo Yellow and Orange Pigments 217... 

Table 11 Non-laked monoazo yellow and orange pigments.

Tables 11 and 12 list the currently available non-laked monoazo yellow and orange pigments. Most of them carry a nitro substituent in the diazonium component, usually in ortho position relative to the azo bridge. The more migration-resistant Pigment Yellow 97 lacks a nitro group in its molecule. Seven monoazo yellow pigments are based on 2-nitro-4-chloroaniline or derivatives as a diazo component.

A variety of diarylide yellow pigments are very fast to light and weather - although monoazo yellow and orange pigments are superior in this respect. 

---