The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 25, 1990
Filed:
Oct. 03, 1989
Jeff Shafe, Redwood City, CA (US);
O James Straley, Redwood City, CA (US);
Gordon McCarty, San Jose, CA (US);
Ravinder K Oswal, Union City, CA (US);
Bernadette A Trammell, Menlo Park, CA (US);
Raychem Corporation, Menlo Park, CA (US);
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.