Effect of uv absorbers containing singlet oxygen quenching groups on the photochemical stability of crystal violet lactone and related colours

Abstract

AbstractThe photofading behaviour of Crystal Violet Lactone was investigated in solution. The contribution of singlet oxygen to that fading was suggested. UV absorbers containing nickel sulphonate quenching groups were prepared and the protecting effect of these compounds towards the photofading of colour materials derived from colour formers was examined in solution and in solid state. It was proposed that nickel salts of 2,2′‐dihydroxy‐4,4′‐dimethoxybenzophenone‐5‐sulphonic acid and its derivative can be applied as effective stabilisers against the photofading of indicator dyes in pressure (or heat) sensitive recording systems.