EFFECT OF STILBENE-SULFONIC ACIDS ON THE PHOTOFADING OF SOME DYES

Abstract

Nickel salt of 4, 4′-bisacetamidostilbene-2, 2′-disulfonic acid (BAAS-Ni), stilbene-florescent dye containing intramolecular singlet-oxygen quenching group, has been synthesized and its effects were examined on the photofading of some dyes in solution and on a solid with a UV irradiation. The rates of photofading of indigoid dye (C. I. Acid Blue 74) and anthraquinoid dyes (C. I. Acid Blue 45 and C. I. Acid Green 25) were accelerated in the presence of BAAS-Ni, but that of Rose Bengal (C. I. Acid Red 94) was retarded remarkably. The effects of added Nickel p-toluene-sulfonate and the Nickel salt of sulfonic acid of dyes on the photo-stability of dyes were also examined.