Removal of treatment prods, e.g. fluorocarbons from textiles - by exposing to radiation having a specified wavelength

摘要

Process for removing a treatment prod. applied to textile substrate comprises exposing the treated substrate to light radiation having a wavelength less than 400 nm. Pref. light having a wavelength of 170-355 (190-220) nm is used. The light is pref. generated by a laser, pref. a UV-excimer laser, or an incoherent UV light source. The laser is pref. a pulse laser having a repetition rate less than 1000 Hz and a pulse time of 10-40 ns. The textile is pref. exposed to radiation for 1s-10 mins per surface unit, pref. using an energy density of 60-3000 mJ/cm2. The textile is pref. exposed to the radiation under inert gas and pref. washed prior to treatment, pref. using an aq. surfactant system. The treatment prod. to be removed is pref. a urea-formaldehyde prod. (esp. three dimensionally cross-linked polymethylolmethylene urea), organosilicon cpd. or a fluorocarbon resin. Pref. only a portion (pref. the outermost region) of the treatment is removed, pref. resulting in a thickness reduction of 10-30% (wrt thickness of treated textile substrate). USE/ADVANTAGE - Useful for removing processing aids, e.g. organosilicon cpds., urea-formaldehyde condensates, melamine prods., alkane diol diurethanes, carbamates or fluorocarbons. Cpds. that could lead to degradation, hardening or discolouration of the textile during later treatment steps are removed without harming the textile prod.