| 摘要 |
A solution of a pyrophosphate of a multivalent metal capable of existing in two valence states, which can be used as an activator solution in the polymerization of a conjugated diolefin as in Specification 711,837, is prepared by dissolving in water a salt of the multivalent metal, present at least in part in a lower valence state, a pyrophosphate of a monovalent cation especially an alkali metal and a different salt of a monovalent cation and an anion which is inert with respect to the multivalent metal, each in amount between 0.1 and 10 parts by weight per 100 parts water, and heating to 40-100 DEG C. for 5-90 mins. out of contact with an oxidizing atmosphere, if desired with the introduction of inert gas. An organic reducing agent, e.g. a sugar may be present in the solution. The multivalent metal may be iron, manganese, copper, vanadium, cobalt. The said different salt may be a fluoride, chloride, nitrate, sulphate, phosphate, borate, tetraborate, formate, acetate, propionate, benzoate, tartrate, salicylate or citrate of an alkali metal. The salt of the multivalent metal and the pyrophosphate are normally present in amounts such there is present from 0.8 to 1.2 atomic weights of metal for each molecular weight pyrophosphate.
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