摘要 |
<p>Described is a method of producing reactive halogen-free polyisobutene having more than 50 mole percent of terminal double bonds and a mean molecular weight Mn of 500 to 5000 Daltons by the cationic polymerization of isobutene or isobutene-containing hydrocarbon mixtures in the liquid phase, the polymerization being carried out at a temperature of -30 to +40 degree C over a heterogeneous polymerization catalyst which includes at least one element which acts as promoter selected from the Ist, IInd, IIIrd, IVth, Vth, VIIth or VIIIth sub-group of the periodic table of the elements or from the IInd, IIIrd, IVth, Vth or VIth main group of the periodic table, or several such elements, each in the form of an oxygen-containing compound, plus zirconium in the form of an oxygen-containing compound, the catalyst not containing technically significant amounts of halogens.</p> |