Abstract: A baked enamel with a thermoplastic polyamide, wherein the the enamel comprises a cross-linking agent that causes chemical cross-linking of the thermoplastic polymer under the action of heat, whereby the cross-linking agent comprises a polyvalent alcohol, a polyisocyanate as well as polyol. A wire with a topcoat of such a baked enamel is also described.

Abstract: An insulated wire capable of withstanding immersion in water and oil. The wire includes an electrical conductor and a coating on the conductor. The coating includes an inner layer formed of at least one layer of enamel which is disposed on the conductor and an outer layer of polyphenylene oxide or of polyphenylene oxide modified by polystyrene on top of the inner layer.

Abstract: The invention relates to a varnish for winding wires, the varnish comprising a copolymer obtained from a thermoplastic or thermosetting resin and containing units derived from silane, and a mineral filler selected from compounds of B, Al, Ti, Zn, Zr, Cr, Fe, silicates, and mixtures thereof. The resin is selected from polyamide imide (PAI), polyester imide (PEI), polyimide (PI), polyester (PE), polyurethane (PU), and polyvinylacetal (PVA). The varnish makes it possible to obtain winding wires of lifetime that is increased by having improved ability to withstand partial discharges and voltage peaks, even at high temperatures. The invention is applicable to manufacturing coils, in particular for variable frequency controllers and converters.

Abstract: An enameling lacquer comprises a base first polymer and a copolymer which is compatible with said first polymer and which contains polymeric chains selected from polysiloxanes, fluorated chains and alkane chains. The lacquer is of particular application to an enameled wire comprising at least one layer of an enamel obtained by reticulation of the lacquer.

Abstract: An enameled wire having high resistance to partial discharges includes an electrical conductor and at least two layers of enamel on the conductor. At least one of these layers is made from resin charged with weakly conductive particles. The outermost layer constitutes an overcoat and is made from thermo-adherent resin. At least the layer directly underlying the overcoat is made from the resin charged with the particles.