Polymers based on conjugated dienes

Abstract

Polymers Ia and Ib carrying functional groups and obtainable by A) 1. hydrogenation of the olefinic double bonds of a polymer IIa comprising a) from 20 to 100% by weight of a conjugated diene, b) from 0 to 80% by weight of an aromatic vinyl compound, and c) from 0 to 20% by weight of further comonomers, to give the hydrogenated polymer IIb, 2. metallation of IIb using an organoalkali metal compound to give IIc, 3. reaction of IIc with a diaziridine III to give IId, and 4. hydrolysis or alcoholysis of IId to give Ia, or by B) 1. partial hydrogenation of IIa to give a partially hydrogenated polymer IIb', 2. epoxidation of the double bonds of IIb' to give IIe, and 3. reaction of IIe with a compound IV carrying functional groups, to give Ib, are suitable as viscosity index improvers for engine oils.

Dependencies are inferred from the claim text.