| 摘要 |
1288406 Bleaching &c cellulose fibres UGINE KUHLMANN 20 Oct 1969 [22 Oct 1968] 51316/69 Heading D1P A process for purifying, bleaching and importing a high degree of absorbency to cellulose e.g. cotton and cellulose/synthetic e.g. cotton/polyester fibres comprises treatment with chlorine dioxide in an amount and for a period sufficient to oxidise fatty substances and other hydrophobic non-cellulosic substances therein but not to bleach the fibres followed by bleaching with a peroxide e.g. hydrogen or sodium peroxide. The concentration of chlorine dioxide which may be in the form of an aqueous solution of pH between 2 and 7 or may be in gaseous form diluted with air or inert gas e.g. N 2 is chosen so that 0.05-0.5% of chlorine dioxide is fixed on the fibres during reaction. This reaction may last for 15 sec. to 30 minutes at a temperature of from 10- 130‹C. The bleaching treatment lasting for a few minutes -30 minutes at 80-140‹C may follow an intermediary washing treatment and is preferably carried out using a peroxide solution containing conventional alkaline agents e.g. caustic soda, sodium carbonate, and may also contain stabilisers e.g. sodium silicate, magnesium silicate, and organic arrestors e.g. ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid or their alkali metal or alkaline earth salts. |
