Conventional Pad-Dry-Cure Process for Durable- Flame and Wrinkle Resistance With Tetrakis (Hydroxymethyl) Phosphonium Hydroxide (THPOH)

Abstract

A durable-flame retardant based on tetrakis (hydroxymethyl ) phosphonium hydroxide (THPOH), urea, and trimethylolmelamine has been developed and applied to cotton fabric. The process is accomplished by padding fabric through a water solution of the three components to a wet pickup of about 75%, drying at moderate temperature, and curing at an elevated temperature. Solutions of 25-34% total solids containing the three components in a molar ratio of 2 : 4 : 1 (THPOH: urea : methylolmelamine), when applied to cotton fabrics of 8-9-oz weight, imparted flame resistance, and only minimal losses in breaking and tearing strength. The treated fabrics retained 91-95% break strength and 73-80% tear strength. Wrinkle recovery angles (W + F) of treated fabrics ranged from 280° to 306°. Wash- wear and durable-press properties are discussed. Little or no yellowing of treated fab rics was observed when bleached with sodium hypochlorite solution and scorched between heated plates. Resin add-ons of fabrics treated in this manner ranged from 15 to 19%. Flame resistance of fabrics treated by this process is retained after boiling the treated fabrics in a soap-sodium carbonate solution for 3 hr or after 15 laundering cycles.