Reduction of Sunlight Yellowing of Wool Fabric Treated with Fluorescent Brightening Agents

Abstract

A wide variety of sulfur-containing compounds has been applied to wool in a search for substances which would protect wool fabric treated with fluorescent brightening agents against the yellowing which occurs on exposure to sunlight and to a filtered xenon arc. The most generally effective are thiols and sulfides which contain a free carboxyl group, the best being thioglycolic acid, 2-mercaptopropionic acid, S-ethylthioglycolic acid, and N-acetyl cysteine. Compounds containing sulfur in higher states of oxidation are much less effective.