No-dry process of applying phosphonium salt precondensates to textiles

摘要

An improved, safe and economical process for impregnating a cellulose fabric with a flame retardant compound comprises: (a) impregnating the fabric with an aqueous solution of a phosphonium salt precondensate and a buffer; (b) adjusting the wet pick-up of the fabric and the concentration of the phosphonium salt precondensate in the pad bath such that the impregnated fabric has a phosphorus content of from about 3% to about 4% and a moisture content of from about 10% to about 20% both based on the weight of the fabric; and (c) without the necessity of drying the impregnated fabric, exposing it to ammonia in an amount and for a period of time sufficient to cure the compound. The impregnated fabric may then be subjected to conventional oxidation and process washing steps to yield the finished fabric.