Patents Assigned to Okuyama International Patent Office
  • Patent number: 7235208
    Abstract: A dust core consists essentially of ferromagnetic powder; and an insulating binder, in which the ferromagnetic powder is dispersed; wherein the insulating binder is a silicone resin comprising a trifunctional alkyl-phenyl silicone resin and optionally containing an inorganic insulator such as an inorganic oxide, carbide or nitride. Preferably the alkyl-phenyl silicone resin is a methyl-phenyl silicone resin and comprises about 20 to 70 mol % of trifunctional groups. The dust core can be produced by pressure-molding a ferromagnetic powder, a lubricant and a trifunctional alkyl-phenyl silicone resin binder and heat treating the molded core at a temperature in the range of about 300 to about 800° C. for a time period in the range of about 20 minutes to about 2 hours in a non-oxidizing atmosphere. The dust core has high magnetic permeability representing the direct current superimposition characteristics, has reduced core loss and has increased mechanical strength.
    Type: Grant
    Filed: January 26, 2005
    Date of Patent: June 26, 2007
    Assignee: Okuyama International Patent Office
    Inventor: Hideharu Moro