O.Z. 0050/40301 Materials which are crosslinkable by ultraviolet radiation under atmospheric oxygen and are based on (meth)acrylate copolymers having a X value of from 10 to 100 are obtained by free radical polymerization, in the presence or absence of a solvent, of a) from 5 to 97.4% by weight of isoamyl acrylate and/or isoamyl methacrylate, b) from 0 to 89.9% by weight of (meth)acrylates whose homopolymers have a glass transition temperature below -30.degree.C, c) from 2.5 to 30% by weight of .alpha.,.beta.-monoolefinically unsaturated compounds whose homopolymers have a glass transition temperature above -30.degree.C, d) from 0 to 10% by weight of monoolefinically unsaturated acids and/or their anhydrides and e) from 0 to 20% by weight of further olefinically unsaturated monomers having one or more of the following functional groups: hydroxyl, amide, epoxide, ether, ester, urethane, urea, primary, secondary and tertiary amine and ether groups, and f) from 0.1 to 5% by weight of a copolymerizable benzophenone derivative or acetophenone derivative, the sum of the percentages by weight X (= a + b + c + d + f) being 100 in each case.