Low, Medium, and High Temperature Catalysts for Formaldehyde-Free Durable Press Finishing by the Glyoxal-Glycol Process

Abstract

Improved catalyst systems have been developed for use in the glyoxal-glycol process under a wide variety of curing conditions. The mild cure process, now conducted with polyethylene as fabric softener in place of the reactive hydrophobic silicones formerly required, takes place at 120-125°C in 2 minutes by aluminum sulfate catalysis in the presence of tartaric acid. Minor amounts of phosphoric acid are added as needed to counteract fabric alkalinity. The medium cure process at 145-160°C occurs within 15 seconds with the same catalyst and activators in the presence of aluminum dihydroxy acetate as buffer. The high temperature process uses aluminum chlorhydroxide as catalyst in the presence of an α-hydroxy acid, and takes place at 170°C or higher. In all three systems, 1,6-hexanediol is the preferred glycol from the standpoint of durable press performance, fabric strength retention, and fabric whiteness.