Resin-rich mica tapes comprising one or more than one layer of mica paper and one or more than one layer of a nonmetallic inorganic fabric, in particular a glass fabric, which are pre-impregnated with an impregnation resin composition comprising an epoxy resin with more than one epoxy group, which is solid or semisolid at ambient temperature, a latent curing agent for said epoxy resin, about 5 to about 20% by weight of hexagonal boron nitride of a particle size (D50) of equal or less than about 3 μm, about 0.05 to about 1% by weight of a wetting agent and a suitable solvent which is removed after pre-impregnation of the mica tape with the impregnation resin mixture are useful to prepare electrical insulations with excellent thermal conductivity and dielectric dissipation factor.

A tape having a first face comprising a continuous surface of mica paper and a second face comprising a support layer, wherein the mica paper comprises 70 to 99 weight percent mica and 1 to 30 weight percent binder and the support layer comprises a film, a paper, a nonwoven fabric, or a woven fabric; wherein the initial elongation of the support layer is equal to or less than the initial elongation of the mica paper; and wherein the support layer is demountably attached to the mica paper such that when a delamination force of 10 N/10 mm or less is imposed on the support layer it can be separated from the mica paper.

A tape having a first face comprising a continuous surface of mica paper and a second face comprising a support layer, wherein the mica paper comprises 70 to 99 weight percent mica and 1 to 30 weight percent binder and the support layer comprises a film, a paper, a nonwoven fabric, or a woven fabric; wherein the initial elongation of the support layer is equal to or less than the initial elongation of the mica paper; and wherein the support layer is demountably attached to the mica paper such that when a delamination force of 10 N/10 mm or less is imposed on the support layer it can be separated from the mica paper.

The present disclosure relates to insulation. Various embodiments thereof may include a solid insulation material and/or a formulation for production of an insulation system. For example, a formulation for an impregnating agent may include: an impregnating resin comprising a cycloaliphatic epoxy resin having a viscosity of less than 1500 mPas at impregnation temperature; and a curing catalyst deposited in the solid insulation material. The curing catalyst may be reactive toward the cycloaliphatic epoxy groups of the cycloaliphatic epoxy resin in the formulation of the impregnating agent but be sufficiently reactively inert with respect to the functional groups of the tape adhesive likewise present in the solid insulation material to confer storage stability to the solid insulation material.

The present disclosure relates to insulation. Various embodiments thereof may include a solid insulation material and/or a formulation for production of an insulation system. For example, a formulation for an impregnating agent may include: an impregnating resin comprising a cycloaliphatic epoxy resin having a viscosity of less than 1500 mPas at impregnation temperature; and a curing catalyst deposited in the solid insulation material. The curing catalyst may be reactive toward the cycloaliphatic epoxy groups of the cycloaliphatic epoxy resin in the formulation of the impregnating agent but be sufficiently reactively inert with respect to the functional groups of the tape adhesive likewise present in the solid insulation material to confer storage stability to the solid insulation material.

High-voltage insulation systems are simplified and can have a thinner design by the use of an external corona shielding system that may include an electrically conductive PTFE fabric. Thermal conductivity may also be improved.

High-voltage insulation systems are simplified and can have a thinner design by the use of an external corona shielding system that may include an electrically conductive PTFE fabric. Thermal conductivity may also be improved.

The present disclosure relates to electrical machines. The teachings thereof may be embodied in a corona shielding system, especially for an electrical machine, e.g., a high-voltage machine, such as a generator for generation of electrical energy, an electric motor, or another piece of electrical equipment having a relatively high rated voltage, e.g., a transformer or a bushing or a cable. A corona shielding system may include: a polymeric matrix; and filler particles comprising mica surrounded by a layer of at least one ceramic metal oxide. The filler particles may be distributed throughout the polymeric matrix.

The present disclosure relates to electrical machines. The teachings thereof may be embodied in a corona shielding system, especially for an electrical machine, e.g., a high-voltage machine, such as a generator for generation of electrical energy, an electric motor, or another piece of electrical equipment having a relatively high rated voltage, e.g., a transformer or a bushing or a cable. A corona shielding system may include: a polymeric matrix; and filler particles comprising mica surrounded by a layer of at least one ceramic metal oxide. The filler particles may be distributed throughout the polymeric matrix.

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.