The invention relates to a solid, in particular strip-shaped insulation material, to the use thereof in a vacuum impregnation method and a thus produced insulation system and to an electric machine using the insulation system, in particular for the medium and high voltage range, that is for medium and high voltage machines, in particular rotating electric machines in the medium and high voltage range and to semi-finished products for electric switching systems. According to the invention, the curing catalyst is a covalently-bridged di-imidazol derivative and/or a covalently-bridged di-pyrazol derivative.