Hydroxymethanesulfonic Acid as a Catalyst for Durable Press Finishing

Abstract

Hydroxymethanesulfonic acid (HMS) is effective as a catalyst for durable-press finishing of cotton and polyester /cotton fabrics by pad-dry-cure, mild cure, and one-step dry-cure treatments. The catalyst is readily formed upon addition of sulfurous acid to pad baths containing free formaldehyde although it can be prepared separately. HMS is a strong acid and can be used in relatively small concentrations. The catalyst appears to be "self-limiting." It dissociates into volatile components during the curing treatment which makes afterwashing unnecessary to prevent changes in strength or wrinkle resistance. HMS catalysis of treatments with dimethylol methyl carbamate and formaldehyde crosslinking agents produced fabrics with high levels of durable-press properties. Mild-cure finishing at 100°C, and pad-dry-cure and one-step dry-cure finishing at 120-140°C were effective with this catalyst.