| 摘要 |
Cotton fabric is impregnated with an alkaline solution of a peroxygen compound which is free from added silicate and which contains at least 0.3 per cent, based on the weight of the goods, of an alkali metal compound yielding orthophosphate ions and a total in the system of 0.02 per cent of a compound yielding alkaline earth metal ions, the solution being buffered within the pH range 9 to 11; therafter, the fabric is heated with steam. The alkaline earth metal compound may be calcium or magnesium salts present as impurities in the fabric or as hardness of the water or may be added as calcium chloride. The alkali metal compound may be a normal or acid sodium phosphate and the peroxygen compound may be hydrogen peroxide or sodium perborate. The pH may be adjusted with sodium hydroxide and the solution may be buffered with borax. In Example II the phosphate ions are derived from both trisodium phosphate dodecahydrate and disodium phosphate duohydrate. |
