Method of improving the processing of refined chemical pulp into viscose by adding anion active agents

摘要

A surface-active agent of the anion active class, preferably one which has substantially the same degree of solubility or insolubility in caustic soda solutions of both mercerizing strength and the more dilute strengths normally present in viscose, is incorporated in the cellulose material or the reagents used at any stage in the production of alkali cellulose or cellulose xanthate prior to completion of xanthation, in an amount of 0.01-0.15 per cent of the weight of the dry cellulose pulp, refined chemical pulp containing not more than 0.15 per cent other extractable matter being used as the starting material. The anion active substance may be added to the cellulose pulp prior to sheet formation, or it may be applied to the pulp sheet. It may be added to the mercerizing lye or may be mixed with the alkali cellulose during the shredding operation. The presence of the anion active substance facilitates the operations of shredding, xanthating, dissolving and filtering. Further, if filaments of subdued lustre are required, the anion active substance facilitates dispersion of the matting substance, e.g. mineral oil. p Smaller quantities of carbon disulphide are required for the xanthation, and the time required for ripening the viscose is reduced. Anion active substances, insoluble in 18 per cent and 5-8 per cent caustic soda solutions, which may be used, are: soaps such as sodium oleate, sodium rosinate, and other alkali salts of fatty or resinic acids; soap-forming substances such as coconut oil, linseed oil, soya bean oil, cotton seed oil, glycol dioleate, oleic acid, rosin, or tall oil; alkyl aryl sulphonates such as the substances known as "Alkanol B," "Nacconol N.R.," and "Santomerse 3"; sulphated fatty alcohols such as sodium lauryl sulphate; sulphonated ethers such as "Tensol 52"; sulphonated naphthenic acids; phosphorated oils such as phosphorated castor oil. Anion active substances which are soluble in both 18 per cent and 5-8 per cent caustic soda are: highly-sulphonated animal or vegetable oils such as the sulphonated castor oil sold under the Registered Trade Mark "Prestabit V"; sulphonated ethers such as the substance sold under the Registered Trade Mark "Triton 720." The viscose obtained may be used in the production of artificial silk, staple fibre, transparent films, or sausage casings.