Improvement in the light fastness properties of dyed and pigmented materials. 1‐The effect of antioxidants on the photostabilisation of dyes in cellulose acetate film

The effect of some added antioxidants on the photodegradation of C.I. Solvent Yellow 33 (quinophthalone) and C.I. Direct Red 39 in cellulose acetate films have been investigated. The effects varied according to antioxidant type. For example, the addition of 2, 6‐di‐t‐butyl‐4‐methylphenol, an effective radical scavenger, afforded little protection against photodegradation, while singlet oxygen quenching of antioxidants such as nickel bis(dithiobenzil), nickel dialkyldithiocarbamate, nickel bis(mesitylenesulphonate) conferred improved resistance of the dyes towards photodegradation.