Improvements in or relating to the preparation of concentrated india rubber latex

摘要

319,410. Dunlop Rubber Co., Ltd., Alcock, H. J., Anode Rubber Co. (England), Ltd., Utermark, W. L., Sickler, J. D., Blickman, J. A., Wal, J. F. de, and Sickler, N. W., (trading as Koopman & Co.), and Aktiebolaget Separator. April 26, 1928. Latex, concentrating.-Rubber latex, on leaving the tree, is treated as soon as possible with from 0.1 to 0.3 per cent of ammonia and is then concentrated by centrifuging. After concentration, it may be treated, for preservation during transport, with further ammonia to bring the percentage up to 0.3 or 0.4 per cent. or with known preservatives such as formalin, &c. After transport the concentrate may be diluted with water, or may have its ammonia content reduced by blowing down with air, by subjecting to reduced pressure, or by partial neutralization with formalin or acid. The con. centrate may be compounded with the usual ingredients added in the dry state or as emulsions. Further concentration, before or after compounding, may be effected by evaporation. The rubber in the skim produced during centrifuging may be separated by coagulation with acid such as dilute sulphuric acid. Specification 219,635 is referred to.