Copolymer, process for their preparation and their use

Copolymer, which can be prepared by reacting at least one olefinically unsaturated monomer (a) in an aqueous or non-aqueous medium containing at least one reaction product (A / B) from DOLLAR A (A) at least one copolymer containing on average at least 0.1 isocyanate-reactive functional groups in the molecule, prepared by radical copolymerization of DOLLAR a (a) at least one olefinically unsaturated monomer and DOLLAR a (b) at least one different from the olefinically unsaturated monomer (a1) olefinically unsaturated monomer of the general formula I DOLLAR AR · 1 · R · 2 · C = CR · 3 · R · 4 ·, DOLLAR A in which the radicals R * 1 *, R * 2 *, R * 3 * and R * 4 * are each independently hydrogen atoms or substituted or unsubstituted are alkyl, cycloalkyl, alkylcycloalkyl, cycloalkylalkyl, aryl, alkylaryl, cycloalkylaryl, arylalkyl or arylcycloalkyl radicals, with the proviso that at least ens two of the variables R · 1 · R · 2 · R · 3 · and R * 4 * are substituted or unsubstituted aryl, arylalkyl or arylcycloalkyl radicals, especially substituted or unsubstituted aryl radicals; DOLLAR A in an aqueous medium or nonaqueous medium; and DOLLAR A (B) at least one polyisocyanate; DOLLAR A radically (co) polymerization, processes for their preparation and their use.