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. 02, 2021
Filed:
Dec. 24, 2015
Hitachi Metals, Ltd., Tokyo, JP;
Norikazu Koyuhara, Mishima-gun, JP;
Yasuharu Miyoshi, Mishima-gun, JP;
Tomoyuki Tada, Mishima-gun, JP;
Satoru Tanaka, Tottori, JP;
HITACHI METALS, LTD., Tokyo, JP;
Abstract
A method for producing MnZn-ferrite comprising Fe, Mn and Zn as main components, and at least Co, Si and Ca as sub-components, the main components in the MnZn-ferrite comprising 53-56% by mol (as FeO) of Fe, and 3-9% by mol (as ZnO) of Zn, the balance being Mn as MnO, comprising the step of sintering a green body to obtain MnZn-ferrite; the sintering comprising a temperature-elevating step, a high-temperature-keeping step, and a cooling step; the high-temperature-keeping step being conducted at a keeping temperature of higher than 1050° C. and lower than 1150° C. in an atmosphere having an oxygen concentration of 0.4-2% by volume; the oxygen concentration being in a range of 0.001-0.2% by volume during cooling from 900° C. to 400° C. in the cooling step; and the cooling speed between (Tc+70)° C. and 100° C. being 50° C./hour or more, wherein Tc represents a Curie temperature (° C.) calculated from % by mass of FeOand ZnO.