the high energy radiation may be used for the acceleration of the curing process but also for the through curing of the applied composition depending on the impregnation layer thickness uv and electron beam radiation can also be used to cure only the surface of the impregnation composition of the invention applied on the substrate in order to reduce emission of volatile monomers of the composition in a thermal curing step afterwards surprisingly it is possible to add the composition according to this invention as additive material in amounts of 5 to 50 wt to curable polymerizable oligomers polymers and copolymers which leads to an improvement of mechanical toughness thermal transfer properties and electrical insulation the composition according to this invention can be used in several fields of applications they are especially useful for the fixing of wound items such as coiled substrates especially of electrical windings like magnet wires in electrical devices like rotors stators or transformers or of coiled metal foils in the electrical sector or coiled substrates on the basis of glass fibers plastic fibers or plastic foils and may also be used for the impregnation of fabrics the invention will be described with reference to the following examples component a is an unsaturated polyester based on maleic anhydride castor oil tetrahydrophthalic anhydride.