Production of polyisobutenes
AssigneeBP Chemicals Limited
InventorsJames Maxwell Kerr, John McMahon, James Mann Scotland
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Abstract
This invention relates to a method of producing polyisobutenes from a feedstock comprising a mixture of C4 hydrocarbons and containing isobutene and at least 5% by weight of 1-butene using a cationic polymerisation catalyst, characterised in that prior to polymerisation, the feedstock is subjected to a pre-treatment step in order to reduce the 1-butene content thereof to a level which is at least 20% lower than that of the 1-butene content in the initial mixed C4 hydrocarbon feedstock prior to the pre-treatment thereof and the polyisobutene so formed is (a) very high in its vinylidene group content and (b) substantially free of halogen.
Claims22
A method of producing polyisobutenes having a number average molecular weight (Mn) in the range from 500-5000 as measured by GPC from a feedstock comprising a mixture of C4 hydrocarbons and containing isobutene and at least 5% by weight of 1-butene using a cationic polymerisation catalyst comprising at least one halogenated compound, characterised in that prior to polymerisation, the feedstock is subjected to a pre-treatment step in order to reduce the 1-butene content thereof to a level which is at least 20% lower than that of the 1-butene content in the initial mixed C4 hydrocarbon feedstock prior to the pre-treatment thereof and the polyisobutene so formed (a) has more than 65% of the unsaturated linkages therein as vinylidene groups and (b) is substantially free of halogen.
Dependencies are inferred from the claim text.