Alkadiene/vinylaromatic copolymers containing side groups, and their use

Abstract

The novel alkadiene/vinyl-aromatic copolymers which contain side groups and have a random, block-like or star-like structure and whose polymerized alkadiene comonomer units are partially or completely selectively hydrogenated, and which contain one or more side groups having one or more radicals capable of (4+2) cycloaddition (Diels-Alder reaction) with dienophiles are suitable as such as viscosity index (VI) improvers or can be used for the preparation of dispersant VI improvers. For this purpose, they are reacted with one or more dienophiles which are capable of a Diels-Alder (4+2) cycloaddition reaction and preferably contain strongly polar functional groups. The resulting selectively hydrogenated alkadiene/vinylaromatic copolymers having one or more side groups which constitute a (4+2) cycloadduct or a Diels-Alder adduct can be modified in their performance characteristics by further reaction with ammonia, an organic amine, an alkylene oxide, a polyalkylene oxide and/or a condensate of ammonia and/or an organic amine with an alkylene oxide.

Dependencies are inferred from the claim text.