Patents Assigned to Steward
  • Patent number: 5422216
    Abstract: A method for preparing the carrier for a developer composition is provided. The method comprises subjecting a ferric oxide and a metal oxide to conditions sufficient to form a ferrite have a spinel structure, mixing the ferrite having a spinel structure with a sintering agent, and sintering in the liquid phase the mixture at temperature conditions of less than about 1375.degree. C. to provide a ferrite carrier devoid of zinc, copper, or nickel in its crystal structure. The ferrite carrier cab be used in a developer composition comprising the ferrite carrier and a toner composition.
    Type: Grant
    Filed: March 1, 1994
    Date of Patent: June 6, 1995
    Assignee: Steward
    Inventors: Danny R. Smith, James N. Kaiser