Patents Represented by Attorney Marguerite E. Richardson Gerstner

Find this attorney in the Justia Lawyer Directory

  • Conductive polymer composition
    Patent number: 4980541
    Abstract: Electrical devices with improved resistance stability comprise a PTC element comprising a conductive polymer and two electrodes. The conductive polymer composition comprises an organic crystalline polymer and carbon black with a pH of less than 5.0. Particularly preferred conductive polymer compositions comprise carbon blacks which have a pH of less than 5.0, a dry resistivity R.sub.CB and a particle size D in nanometers such that R.sub.CB /D is at most 0.1. Electrical devices of the invention include heaters and circuit protection devices.
    Type: Grant
    Filed: October 3, 1989
    Date of Patent: December 25, 1990
    Assignee: Raychem Corporation
    Inventors: Jeff Shafe, O. James Straley, Gordon McCarty, Ravinder K. Oswal, Bernadette A. Trammell