Vapor-Phase Treatment of Cotton, Fabrics with Formaldehyde Catalyzed by Sulfur Dioxide1

Abstract

A process has been developed for cross-linking cotton fabrics with formaldehyde at temperatures between 80°C and 130°C using sulfur dioxide as a catalyst. Reaction times of 2-5 min are required. To obtain wrinkle recovery angles between 300° and 330°, fabrics should be pretreated with a soft film-forming additive. Wash-wear ratings of 41 2 and crease retention ratings of 4 were obtained with twill. Trouser cuffs made from twill or printcloth had approximately double the laundering life of cuffs of equal wash-wear ratings made with Permafresh. Fabrics treated with formaldehyde retained their wrinkle recovery values through at least 15 wash-dry cycles. Ammonium chloride, substituted for the sulfur dioxide catalyst, caused the desired amount of formaldehyde to react in 1-2 min. When zinc nitrate was substituted for sulfur dioxide, the reaction required 5-6 min.