Low molecular weight binders which contain a double bond capable of polymerisation are used for the formulation of coating compounds which cure by means of UV rays: In UV curing, crosslinking is initiated by radicals. The radicals are formed by the photoinitiators or synergists (see 5). Polymerisation continues in accordance with the conventional polymerisation mechanism by way of: initiation reaction, chain termination reaction. This may take place by a combination of two radicals, by disproportionation or ...