GB268505A - Manufacture of wool like cellulosic material - Google Patents

Abstract

268,505. Harrison, W. Feb. 12, 1926. Fibres, treating; yarns, treating with liquids, gases, and vapours.-Cellulosic fibres such as cotton linen, ramie or jute whether in the form of fibres, yarns, &c. acquire many of the properties of wool by treating first with caustic alkali or alkali sulphide and carbon disulphide to form an unstable insoluble xanthate, and then converting the latter into a stable compound by treatment with a mild oxidising-agent which will not split off the carbon disulphide combined with cellulose. Suitable oxidizing-agents are nitrous acid or oxides of nitrogen, ferricyanides, iodine, and oxygen or air preferably in the presence of a catalyst such as oxides of iron, cobalt, nickel, or manganese; in the case of air it is necessary that the material should be moist, the air cold, and the treatment prolonged, or that a catalyst should be present. The carbon disulphide may be applied in the form of vapour, or in solution in an inert solvent such as benzene, and it mav be applied before or after treatment with caustic alkali &c. or simultaneously therewith in the form of an emulsion or collodial solution; and the material may or may not be subjected to tension during either of these treatments or during the subsequent washing-operation. The unstable xanthate. preferably after washing with or without the application of tension or after acidifying with a weak acid such as acetic acid, is subjected to treatment with the mild oxidizing-agent. The oxidized stable product, if coloured, may be decolourised by treatment with sulphurous acid. The dried product may be shrunk by treatment with ammonia, sodium sulphide, or sodium sulphite preferably in the presence of alkali. Specifications 19912/01, 126,174, 216,476 and 216,477 are referred to.