An insulating tape for manufacturing an insulating sleeve, impregnated with a hot-curing epoxy-resin acid-anhydride system, for electrical conductors.The insulating tape for manufacturing an insulating sleeve, impregnated with a hot-curing epoxy resin-hardener system, consists of an inorganic material, of high dielectric strength which is applied to a flexible support and is bonded by means of a binder and contains an accelerator which promotes the curing reaction, whereby the binder/accelerator mixture constitutes a system that is self-curing at the curing temperature of the impregnating resin.In the case of the binder/accelerator mixture, the binder consists of a physiologically innocuous, ring-epoxidized, cycloaliphatic epoxy resin, modified by molecular enhancement, with an epoxide equivalent greater than 200, and the accelerator adducts of piperazines, substituted in 1 position, with (meth)acrylate compounds.Such an insulating tape (1) can be stored indefinitely at ambient temperature and insulating sleeves (5) of electrical conductors (6) manufactured with it can be cured after being impregnated with epoxy resin/acid-anhydride-systems in economically short times and possess excellent rigidity and a high heat-distortion temperature.