Patent ID: 7381483
Filing Date: 2008-06-03
Classification: C08K

Abstract:
1. A core made of a composite magnetic material having a relative permeability in a range from 1 to 29 in a frequency range from 20 kHz to 2.5 MHz, wherein the composite magnetic material comprises: a mixture of cobalt and nickel particles having an average diameter in a range from 1 to 100 micrometers, and a polymer base binding the mixture of particles and defining the shape of the core, the polymer base comprising an epoxy resin consisting of 4,4′ isopropylidenediphend epichlorohydrin resin, alkyl glycidyl ether and poly-acrylate ether, and a hardener consisting of diethylenetriamine and 2-hydroxyethydiethylenetriamine.