Polymer composition containing at least one middle molecular weight reactive polyisobutene

A composition as claimed in any of the preceding claims, wherein the component b) is selected from among polymers which comprise, in polymerized/copolymerized form

• I) at least one styrene compound of the formula
• 4
• where
• R1 and R2 are each, independently of one another, hydrogen, C1-C30-alkyl, hydroxy, alkoxy or halogen, R3 is hydrogen or C1-C8-alkyl, and,
• II) if desired, at least one monomer which is different from I), is copolymerizable therewith and has at least one α,β-ethylenically unsaturated double bond.

A process for preparing a polyisobutene derivative by reaction of at least part of the double bonds present in a medium molecular weight, reactive polyisobutene in a single-stage or multistage functionalization selected from among:

• i) reaction with a compound containing at least one aromatic or heteroaromatic group in the presence of an alkylation catalyst to give a compound alkylated by polyisobutene, and, if desired, reaction in a further functionalization,
• ii) reaction with a peroxy compound to give an at least partially epoxidized polyisobutene,
• iii) reaction with an alkene which has an electrophilically substituted double bond in an ene reaction and, if desired, reaction in a further functionalization,
• iv) reaction with carbon monoxide and hydrogen in the presence of a hydroformylation catalyst to give an at least partially hydroformylated polyisobutene and, if desired, reaction in a further functionalization,
• v) reaction with hydrogen sulfide or a thiol in the presence of a catalyst to give a polyisobutene which is at least partially functionalized by thio groups,
• vi) reaction with a silane in the presence of a silylation catalyst to give a polyisobutene which is at least partially functionalized by silyl groups,
• vii) reaction with a halogen or a hydrogen halide in the presence of a-catalyst or electromagnetic radiation to give an at least partially halogenated polyisobutene,
• viii) reaction with a borane and subsequent oxidative cleavage to give an at least partially hydroxylated polyisobutene, and
• ix) reaction with SO3 or a compound capable of releasing SO3 to give a polyisobutene which is at least paretially functionalized by sulfo groups.