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. 17, 1991
Filed:
Jun. 14, 1989
Applicant:
Inventors:
Akihide Igari, Tokyo, JP;
Zenbee Nakagawa, Kanagawa, JP;
Assignee:
Somar Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01B / ;
U.S. Cl.
CPC ...
252518 ; 264 61 ; 264 66 ; 264 65 ; 264104 ; 264235 ; 296101 ; 419 19 ; 419 48 ; 419 49 ; 419 53 ;
Abstract
A varistor material comprising two crystalline phases of ZnO and ZnMn.sub.2 O.sub.4, wherein Zn and Mn are present at such a ratio that 3 to 7% by mol of ZnO is contained per 100% by mol of ZnO+MnO and the nonlinear index (.alpha.) of the varistor properties is at least 10; and a process for the production of the same, which comprises adding a manganese compound to ZnO at such a ratio as to give a content of MnO, sintering the mixture at 1100.degree. to 1350.degree. C., and further annealing the obtained sintered material at a temperature lower than the sintering temperature by at least 50.degree. C. and higher than 1000.degree. C. are disclosed.