| 摘要 |
Isoprene is polymerized in the presence of a catalyst prepared by reacting an aluminium trialkyl and titanium tetrachloride in an inert solvent in such amounts that the atomic ratio of Al/Ti ranges from 0,81 to 2,0/1 and then removing the inert solvent in a sufficient quantity as to remove at least 30% and not more than 75% of the hydrocarbon-soluble reaction product of the alkyl and tetrachloride. Specified alluminium compounds are the trimethyl, tripropyl, triisobutyl, and trioctyl. The reaction may take place in the absence of a solvent other than that for the catalyst, but it is preferred that a solvent is present. Specified inert solvents are pentane, hexane, heptane and benzene.ALSO:An isoprene polymerization catalyst is prepared by reacting an aluminium trialkyl and titanium tetrachloride in an inert solvent in such amounts that the atomic ratio of Al/Ti ranges from 0.8/1 to 2.0/1 and then removing the inert solvent in such an amount as to remove at least 30% and not more than 75% of the hydrocarbon-soluble reaction product of the trialkyl and tetrachloride. Specified aluminium compounds are the trimethyl, tripropyl, triisobutyl and trioctyl. Specified inert solvents are pentane, hexane, heptane and benzene. In examples, the precipitate formed by interaction of the Al and Ti compounds is removed by centrifuging, the desired proportion of the liquid phase is withdrawn and the precipitate is redispersed in the liquid, the volume of liquid withdrawn being replaced by fresh solvent.
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