| 摘要 |
313,085. Du Pont de Nemours & Co., E. I., (Assignees of Schwartz, G. L., and McCormick, F. H.). June 6, 1928, [Convention date]. Absorbent paper; pulp, preparation of.-Pulp for absorbent paper, suitable as a base for impregnating compositions such as contain resins, pyroxylin, rubber and the like, is obtained, by treating pulp with a swelling agent having the effect of kinking or curling the cellulose fibres and thereafter washing out the swelling agent. Caustic soda solutions are suitable but other caustic alkalies, sulphuric acid, zinc chloride, various thiocyanates, ferric chloride, and cuprammonium solutions may be used. In any treatment, the strength of the solution, the temperature and duration are such that oils, resins and other impurities which interfere with the wetting are dissolved or destroyed and then the temperature is lowered to produce a swelling action on the cellulose, curling but not dissolving it. An aqueous caustic soda solution may be used at normal room temperature, when it exerts a solvent action, and then cooled to effect the curling before the washing operation. The process is applicable to mechanical wood pulp, kraft, jute, soda pulp, rope, sulphite, and linen. |
