Process for imparting flame resistance and resistance to ultraviolet light-induced shade change to vat-dyed cellulosic textile materials

Claim 1

A process for imparting resistance to ultraviolet light-induced shade change to a vat-dyed cellulosic flame resistant textile material which comprises: (a) impregnating a cellulosic textile material with an aqueous solution of a tetrakis(hydroxymethyl)phosphonium salt, a mixture of tetrakis(hydroxymethyl)phosphonium salts, or a partially polymerized methylol phosphorus material to deposit thereon about 3-7% phosphorus based on the weight of the untreated textile material; (b) partially drying the impregnated textile material; (c) contacting the partially dried textile material with about 2-6 gram-moles of gaseous ammonia per gram-atom of phosphorus present thereon to deposit therein a substantially water-insoluble phosphorus-containing polymer; (d) contacting the ammoniated textile material with an oxidizing solution containing about 18-25% hydrogen peroxide, 30-50% acetic acid, and 50-30% water, at a temperature above about 50° C. for a period of from about 5-25 minutes; (e) rinsing the oxidized textile material with water, and drying.