| 摘要 |
Synthetic fibres are bleached using a soln., at 100-135 degrees C,that contains H2O2 and has pH 3-7. Pref. the soln. contains ≤ 65 (pref. 20-35) wt.% H2O2 soln., e.g. 1-20 ml/l of a 35 wt.% soln. It may include: (1) stabilisers, pref. <0.5 (esp. 0.3) wt.% alkaline earth (e.g. Mg and/or Ca) metal salts; (2) organic complexing agents, pref. aminocarboxylic acids and their alkali salts at 0.1-5 (pref. 0.2-1) g/l; (3) 0.1-5 (pref. 0.2-1) g/l bleaching auxiliary (esp. protein degradation product, alkyl- or alkylaryl-phosphate); (4) surfactant, pref. alkyl-phenol condensate; alkyl-aryl-sulphonic acid and/or alkyl sulphate at 0.5-3 (pref. 1-2) g/l; (5) 0.5-10 (pref. 2-3) g/l polyphosphate, partic. of formulae: Mn+2PnO3n+1 or MnPnO3n, where M = alkali(ne earth) or NH4 ion; n = 1-6; (6) 0.1-5 g/l optical brightener. Treatment is at pH 5-7 and 120-130 degrees C (corresponding to 1-3.5, partic. 2-3, atm.), using a goods to liquor ratio 1:3-40, pref. 1:10-20. Bleaching is typically for 80-120 mins. at 100 degrees C or for 10-30 mins. at 135 degrees C. |
