Patent ID: 8580348

Claim:
A method for conferring flame retardant properties to a textile material, comprising the steps of: (a) impregnating the material with an aqueous solution of a treatment agent comprising a poly(hydroxyorgano)phosphonium compound; (b) drying the impregnated material; (c) curing the dried impregnated material with ammonia to produce a cured water-insoluble polymer, wherein: said polymer is mechanically fixed within the fibers of the material, and said curing increases the atomic ratio of N:P by at least 0.8; (d) oxidizing the cured polymer to convert trivalent phosphorus to pentavalent phosphorus; and (e) washing and drying the material; wherein one or both of steps (d) and (e) result in the co-production of an aqueous effluent which comprises 1,3,5-triaza-7-phosphaadamantane and/or derivatives thereof and said method further comprises removing said 1,3,5-triaza-7-phosphaadamantane and/or derivatives thereof from said aqueous effluent.