Various embodiments may include a solid insulation material, e.g. in tape form, the use thereof in a vacuum impregnation process, and/or an insulation system produced therewith and also an electrical machine having the insulation system, for the medium- and high-voltage sector. Some examples include rotating electrical machines in the medium- and high-voltage sector and also semifinished products for electrical switchgear. The solid insulation material and the insulation system produced therewith are characterized in that it can be produced in an anhydride-free manner, wherein the curing catalyst is, for example, an adduct of a 1H-imidazole and/or 1H-imidazole derivative with a compound containing oxirane groups.