| 摘要 |
1457870 Cellulose acetate webs H X D PEDROSA 18 Oct 1973 [26 July 1972] 34947/72 Heading B5B [Also in Divisions C3 and B1] A semipermeable membrane of cellulose acetate has cupric ferrocyanide uniformly distributed throughout the thickness of the membrane and may also possess a series of fibres or channels extending the length or breadth thereof and extending beyond one edge. The membrane may be produced by one of the following methods:- (a) soaking a web of cellulose acetate in an aqueous solution of cupric ferrocyanide, which may contain acetone, and then drying the web; (b) forming a mixture of cellulose acetate, cupric ferrocyanide, water and optionally acetone, pouring the mixture in a vessel and removing the solvent to form the web; (c) placing a bag of cellulose acetate containing an aqueous solution of CuSO 4 in a vessel containing an aqueous solution of potassium ferrocyanide whereby the solutions diffuse into the web from either side and react to form cupric ferrocyanide. |
