UV-crosslinkable materials based on (meth)acrylate polymers

A UV-crosslinkable material comprising a copolymer of (i) an ester of (meth)acrylic acid and a C.sub.1 -C.sub.24 alkanol, having a K value of from 10 to 150, and (ii) from 0.01 to 20% by weight, based on the copolymer, of at least one copolymerized monomer of the formula I ##STR26## where R is a straight-chain alkyl of 1 to 3 carbon atoms, branched, unsubstituted or substituted alkyl of 3 to 4 carbon atoms, aryl or a radical R.sup.1 and

• R.sup.1 is a radical ##STR27## where R.sup.2 to R.sup.6 are identical or different and are each H, aryl of 1 to 4 carbon atoms, a non-ortho OH group, OCH.sub.3, OC.sub.2 H.sub.5, SH, SCH.sub.3, CL, F, CN, COOH, COO(C.sub.1 -C.sub.3 -alkyl), CF.sub.3, N(CH.sub.3).sub.2, N(C.sub.2 H.sub.5).sub.2, N(CH.sub.3)C.sub.6 C.sub.5, .sup.+ N(CH.sub.3).sub.3 X.sup.-, or .sup.+ N(CH.sub.3).sub.2 X.sup.-, where X.sup.- is an acid anion, eg. Cl.sup.-, Br.sup.-, acetate, HSO.sub.4.sup.-, H.sub.2 PO.sub.4.sup.- or NO.sub.3.sup.- and one or more of the radicals R.sup.2 to R.sup.6 are a radical ##STR28## where Sp is one of the spacer groups of the following type ##STR29## and R' is H, C.sub.1 -C.sub.4 -alkyl or phenyl,
• R" is H or C.sub.1 -C.sub.4 -alkyl and
• R"' is H or CH.sub.3
• and where the radicals X may be identical or different and are each a divalent, unsubstituted or substituted alkylene radical which may be perfluorinated, an unsubstituted or substituted cycloalkylene radical of 5 to 10 carbon atoms or an unsubstituted or substituted o-, m- or p-phenylene radical, which are bonded directly to one another and/or are bonded to one another by idential or different groups Y, and Y is a divalent radical from the group consisting of ##STR30## k and m are each from 1 to 10 and l and n are each from 0 to 25.