Coil and electrical strip or electrical sheet
Assigneevoestalpine Stahl GmbH
InventorsRonald Fluch, Roman Tiefenthaller
Life of this patent
Estimating the term…
Abstract
A coil and an electrical strip or electrical sheet with at least one heat-hardening hotmelt varnish, namely a baked enamel layer, provided on its flat sides, which has an epoxy resin base, at least one hardener, and at least one filler, are disclosed. In order to achieve a high storage stability and long-term temperature stability, the proposal is made for the filler of the baked enamel layer to have a metal carbonate, sulfate, sulfide, silicate, or phosphate or any mix of a plurality of these.
Claims12
An electrical strip or electrical sheet for producing a laminated core through baking of a heat-hardening hotmelt varnish, comprising:
- at least one heat-hardening hotmelt varnish provided on flat sides of the electrical strip or electrical sheet, which has an epoxy resin base, at least one hardener comprising a dicyandiamide base, and at least one filler, wherein the at least one filler in the heat-hardening hotmelt varnish is selected from the group consisting of:
- a metal carbonate, a metal sulfate, and any combination thereof, wherein the filler has an average grain size of 0.6 to 3 μm, and wherein the heat-hardening hotmelt varnish contains 7 to 16% by volume of filler.
A method of increasing dimensional stability of a coil, comprising:
- using at least one of the group consisting of:
- a metal carbonate, a metal sulfate, and any combination thereof as a filler in a heat-hardening hotmelt varnish with an epoxy resin base and a hardener comprising a dicyandiamide base to coat an electrical strip or electrical sheet on at least one of its flat sides, wherein the filler has an average grain size of 0.6 to 3 μm, and the heat-hardening hotmelt varnish contains 7 to 16% by volume of filler;
- and
- forming the coil from the coated electrical strip or electrical sheet.
A method of increasing long-term temperature resistance of a laminated core;
- comprising:
- using at least one of the group consisting of:
- a metal carbonate, a metal sulfate, and any combination thereof as a filler in a heat-hardening hotmelt varnish with an epoxy resin base and a hardener comprising a dicyandiamide base to coat an electrical strip or electrical sheet on at least one of its flat sides, wherein the filler has an average grain size of 0.6 to 3 μm, and the heat-hardening hotmelt varnish contains 7 to 16% by volume of filler;
- and
- baking the heat-hardening hotmelt varnish to produce the laminated core from the coated electrical strip or electrical sheet.
Dependencies are inferred from the claim text.