Process for clotting of the emulsions are similar to the latex

摘要

Caoutchouc, synthetic.-Latices obtained by the polymerization of emulsions of diolefines are coagulated by the addition of salts, preferably in concentrated aqueous solution. The emulsifying agent can then be removed by washing. When diolefines are polymerized in emulsions formed by the aid of alkylated naphthalene sulphonates or by means of acid emulsifiers such as the hydrochloride of pentadecyl-m -glyoxalidine or of the o -diethylamino-4-ethoxy-anilide of oleic acid, the latices cannot be coagulated by acids, but are readily coagulated by salts, such as the alkali salts of inorganic or organic acids, e.g. sodium, potassium and ammonium halides, carbonates, sulphates, nitrates, phosphates, acetates, benzene sulphonates, naphthalene sulphonates and the like. Salts of polyvalent metals will also cause coagulation, but insoluble compounds are often formed by reaction with the emulsifying agent, which becomes enclosed in the coagulum, and can only be removed with difficulty. In the examples (1) a latex produced from an emulsion of butadiene or isoprene with sodium oleate solution is coagulated by a saturated solution of sodium chloride; (2) a latex produced from an emulsion of dimethyl butadiene with sodium oleate solution is coagulated by saturated sodium acetate solution; (3) a latex produced from an emulsion of butadiene with sodium isobutyl naphthalene sulphonate is coagulated by saturated sodium carbonate solution; (4) a latex produced from an emulsion of butadiene with hydrochloride of o -diethylamino-4-ethoxy-anilide of oleic acid is coagulated by saturated disodium phosphate solution. Specification 330,272, [Class 2 (iii), Dyes &c.], is referred to.