Patents by Inventor Kenneth L. Berry

Kenneth L. Berry has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Acicular .alpha.-iron particles and recording media employing same
    Patent number: 4273807
    Abstract: Particulate product containing at least 75 weight % iron (total iron content) and at least 25 weight % acicular .alpha.-iron metal, process for making said product and magnetic recording medium having said product incorporated therein, said product having a length less than 1 micron (.mu.), a length to diameter ratio of at least about 10:1, a coercivity (iH.sub.c), of greater than about 800 oersteds, a saturation magnetization (.sigma..sub.s) of at least 110 electromagnetic units/gram (emu/g), a residual (remanent) magnetization (.sigma..sub.r) of at least 50 emu/g, and a ratio (.sigma..sub.r /.sigma..sub.s) of residual (remanent) magnetization (.sigma..sub.r) to saturation magnetization of at least about 0.45.
    Type: Grant
    Filed: November 16, 1979
    Date of Patent: June 16, 1981
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Kenneth L. Berry
  • Acicular .alpha.-iron particles, their preparation and recording media employing same
    Patent number: 4207092
    Abstract: Particulate product containing at least 75 weight % iron (total iron content) and at least 25 weight % acicular .alpha.-iron metal, process for making said product and magnetic recording medium having said product incorporated therein, said product having a length less than 1 micron (.mu.), a length to diameter ratio of at least about 10:1, a coercivity (iH.sub.c), of greater than about 800 oersteds, a saturation magnetization (.sigma..sub.s) of at least 110 electromagnetic units/gram (emu/g), a residual (remanent) magnetization (.sigma..sub.r) of at least 50 emu/g, and a ratio (.sigma..sub.r /.sigma..sub.s) of residual (remanent) magnetization (.sigma..sub.r) to saturation magnetization of at least about 0.45.
    Type: Grant
    Filed: March 19, 1979
    Date of Patent: June 10, 1980
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Kenneth L. Berry