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:
Mar. 22, 1994
Filed:
Sep. 09, 1992
Hideo Ochi, Misato, JP;
Akihide Igari, Saitama, JP;
Masaaki Toyoda, Saitama, JP;
Zenbee Nakagawa, Yokohama, JP;
Somar Corporation, , JP;
Abstract
A varistor having a non-linear coefficient of at least 40 and improved stability for DC stress is produced by a method including a step of mixing ZnO powder with a solvent solution of Mn and Pb compounds, a step of calcining the resultig mixture, and a step of pulverizing the calcined product to obtain a pulverized product. These steps are performed while preventing the contamination with a Group IIIb or Ia element, so that the pulverized product has MnO and PbO contents of 3-7 mole % and 0.003-0.01 mole %, respectively, and a content of impurity compounds of a IIIb or Ia element of not greater than 20 ppm by weight. The pulverized product is molded and sintered to obtain the varistor.