| abstract |
Use of polyisobutene reaction products essentially free of acid groups, which can be obtained by reacting polyisobutene (A) with a number average molecular weight Mn of 200 to 10000 with derivatives of maleic acid (B), wherein the derivatives are selected from group consisting of monoalkyl esters, dialkyl esters and anhydrides, in a stoichiometric ratio of more than one equivalent of maleic acid derivatives, by terminal α and β double bonds (in total), determined by 13C NMR in polyisobutene (A), in which the degree of bismaleinization, indicated as 100% x [(% by weight (BM PIBSA) / (% by weight (BM PIBSA) +% by weight (PIBSA))], where% by weight represents the percentages in weight of the respective component, PIBSA represents monomaleinized polyisobutene and BM PIBSA represents more than monomaleinized polyisobutene, amounts to at least 11%, provided that - in the case of the use of monoalkyl esters and / or dialkyl esters as compu this (B), more than 90% of the ester groups present in the reaction product are kept and / or - in the case of using anhydrides as compound (B), more than 90% of the anhydride groups present are kept in the reaction product, as corrosion inhibitors in fuels or in lubricants, preferably in fuels, particularly preferably in fuels with a content of alkali and / or alkaline earth metals and / or zinc of at least 0.1 ppm by weight . |