| 摘要 |
Catalysts used in polymerization (see Group IV (a)) consist of borohydrides of titanium, zirconium or vanadium or mixtures thereof, and specified are titanium and zirconium borohydrides themselves and titanium halo-borohydrides such as the monochloroborohydride. Subsequent to polymerization the catalysts may be deactivated and the products, purified with materials such as methanol, ethanol and ethanolic hydrochloric acid. In the Provisional Specifications the catalysts may be prepared in situ by reaction of lithium or aluminium borohydride with titanium, zirconium and vanadium compounds.ALSO:a -Olefins are catalytically polymerized with a titanium, zirconium or vanadium borohydride or mixtures thereof, e.g. titanium or zirconium borohydride themselves or titanium haloborohydrides such as the monochloroborohydride. Olefins specified are ethylene, propylene, butene, pentene, hexene, isobutene, styrene and mixtures thereof. The polymerization may be batchwise or continuous, preferably in the absence of oxygen and water, and desirably in an inert medium such as petroleum ether, pentane, hexane, cyclohexane, tetrahydronaphthalene, decahydronaphthalene, higher paraffins, benzene, xylene, dichlorobenzene, chlorinated naphthalene and mixtures thereof. In examples, ethylene is added intermittently throughout the reaction, which may be terminated and the product purified by means of materials such as methanol, ethanol and ethanolic hydrochloric acid. The polymers produced are linear and find application as films, fibres and moulded articles. In the Provisional Specifications the catalyst is formed in situ by reaction of lithium or aluminium borohydride with various specified titanium, zirconium and vanadium compounds. |
