| 摘要 |
In an aqueous emulsion polymerization process using as catalyst an oxidant and a pyrophosphate of a multivalent metal capable of existing in two states as an activator composition, the activator composition is prepared by dissolving in water a pyrophosphate of a monovalent cation, a salt of such a multivalent metal under conditions such that it is present at least in part in a lower valence state, and a different salt of a monovalent cation and an anion which is inert with respect to ions of said multivalent metal, heating this solution out of contact with free oxygen to a temperature between 40 and 100 DEG C. for 5 to 90 minutes and then cooling and adding this solution and oxidant so that there is added, based upon 100 parts by weight of said monomeric material, 0.01 to 3 millimol parts of said multivalent metal, pyrophosphate and oxidant and 0.1 to 5 parts of said different salt. The process is particularly applicable to the production of copolymers from 65 to 90 per cent. of butadiene, and 35 per cent. to 10 per cent. of styrene, but other monomers specified are isoprene, piperylene, 3-furyl-1, 3-butadiene, 3-methoxy-1,3-butadiene, chloroprene, bromoprene, methyl chloroprene; styrene, p-chloro-styrene, p-methoxystyrene, alpha-methyl styrene, vinyl naphthalene; acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, methyl alphachloroacrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl ethacrylate, acrylonitrile, methacrylonitrile, methacrylamide; methyl isopropylketone, methyl vinyl ketone; methyl vinyl ether; vinyl ethinyl alkyl carbinols; vinyl acetate, vinyl chloride, vinyl furane, vinylidene chloride, vinyl carbazole, vinyl acetylene and mixtures thereof. Specified multivalent metals are iron, manganese, copper, vanadium and cobalt. Specified oxidants are hydrogen peroxide, a pernitrate, a persulphate, a permanaganate, benzol peroxide, tertiary butyl hydroperoxide, methyl cyclohexyl hydroperoxide, cumene peroxide, 2 - (4 - methoxybenzene diazothiomercapto) - naphthalene, 1 - (2, 4 - dimethyl benzene diazomercapto) - naphthalene. Specified "different salts" are sodium fluoride, tetraborate, benzoate, salicylate, sulphate, and chloride, potassium chloride and tartrate. Emulsifying agents such as the potassium salt of tetrahydroabietic acid, potassium laurate and oleate, mercaptans such as alkyl mercaptans of C12-C14 atoms, alcohols such as methanol, ethylene glycol, glycerine and erythritol, and reducing sugars may also be present. Specification 711,892, [Group III], is referred to.
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