A method for the preparation of rubber, if nsta ends from the concentrated aqueous dispersions of rubber or similar plants resins

摘要

324,104. Dunlop Rubber Co., Ltd., Twiss, D. F., Purhis, F. T., and Murphy, E. A. Oct. IS, 1928. Latex, treating.-Rubber articles are made from concentrated aqueous dispersions by adding one or more non-coagulants for rubber which decompose or interact to form coagulants on a rise in temperature, and heating the mix to produce a gel. Additions specified are ammonium persulphate alone or with trioxymethylene, aldehydes, or other neutral organic substances capable of being oxidized to acid substances, ammonium thiosulphate or ammonium salts of other sulphur acids capable of yielding oxidation products of greater acidity, for example, dithionates. Ammonium or barium thiosulphate may also be used alone, or with oxidizing agents such as salts of per acids, or hydrogen peroxide, or with salts such as lead acetate which accelerate decomposition of the thiosulphate. The amount added may be of the order of 0.1 per cent of each ingredient and the temperature of gelling about 90‹ C. The rubber &c. dispersion may be vulcanized or not, and may contain factice, waste, reclaim, mineral or synthetic rubber, vulcanizing ingredients, dyes, fillers, &c. Specification 290,313 is referred to.