| 摘要 |
1,156,947. Treating cotton fabrics. E. I. DU PONT DE NEMOURS & CO. 19 Oct., 1966 [19 Oct., 1965; 28 Feb., 1966], No. 46839/66. Heading DIP. A woven cotton fabric is rendered suitable for dyeing by subjecting it in open width and extended state to two treatments, stage 1 comprising (a) dampening it with an aqueous solution containing 6-13% by weight caustic soda or caustic potash, (b) subjecting it to the direct action of saturated steam at about atmospheric pressure for not more than 2 minutes and (c) rinsing it with water, and stage 2 comprising (a) dampening it with an aqueous solution containing 1-5% by weight caustic soda or caustic potash, 0.2-2.5 % by weight H 2 O 2 and a peroxide stabilizer at a concentration effective to prevent excessive decomposition of the H 2 O 2 , (b) subjecting it to the direct action of saturated steam at about atmospheric pressure for not more than 2 minutes and (c) rinsing it with water. After stage 2 the fabric may be further subjected to a third treatment stage in which it is (a) dampened with an aqueous solution containing 0.8-3 % by weight caustic soda or caustic potash, 0.2-2.5% by weight H 2 O 2 and a peroxide stabilizer at a concentration effective to prevent excessive decomposition of the H 2 O 2 (b) subjected to the direct action of saturated steam at about atmospheric pressure for not more than 2 minutes and (c) rinsed with water. The fabric which may be in the greige state may comprise cotton fibres alone or in admixture with nylon or polyester fibres. The solution used in stage 1 may also contain 0.2-2% by weight of a molecularly dehydrated phosphate and/or a wetting agent and the solutions used in stages 2 and 3 may also contain wetting agents and/or an organic heavy metal sequestering agent, suitable wetting agents being common soluble soaps and synthetic detergents, e.g. sodium and potassium alkyl sulphates and alkyl and alkyl benzene sulphonates, ethylene oxide condensates and alkoxylate aryl polyether alcohols and suitable sequestering agents are ethylene diamine tetraacetic acid, diethylene triamine pentoacetic acid, nitrilotriacetic acid and the hydroxyalkyl ethylene diamine triacetic acids and their sodium salts. Suitable stabilizers used in the solutions of stages 2 and 3 are sodium and potassium pyrophosphates, sodium hexametaphosphate, sodium tripolyphosphates sodium silicate or mixtures thereof e.g. sodium silicate with a phosphate arid sodium silicate wth sodium pyrophosphate and magnesium sulphate. |
