Process for making flame-resistant cellulosic fabrics

摘要

Cellulosic fabrics are rendered flame resistant in a two-step procedure by applying first a tetrakis(hydroxymethyl) phosphonium salt/urea precondensate ammoniated to crosslink and form an insoluble phosphorus-containing polymer within the fiber structure followed by treatment with a tetrakis(hydroxymethyl) phosphonium salt. The two-step process using these chemically related phorphorus-containing flame retardants provide sufficient phosphorus in and on the cellulosic fabric to impart a predetermined minimum flame resistance. Cellulosic fabrics, primarily cotton, having flame resistant properties durable to washing yet retaining pliant, nont-stiff hand result.