IP Library Granted Patent US 7,255,807
Granted Patent B2
US 7,255,807 · App. 10/829,291 · Granted Aug 14, 2007

Bond magnet and ferrite magnetic powder for bond magnet

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Quick Facts
Patent No.
US 7,255,807
App. No.
10/829,291
Granted
Aug 14, 2007
Kind
B2
Abstract

A ferrite magnetic powder for bond magnet that experiences only small decrease in coercivity when molded into a bond magnet is provided, which is a ferrite magnetic powder that includes an alkaline-earth metal constituent and exhibits a decrease in coercivity of not greater than 600 Oe when subjected to a prescribed molding test. The magnetic powder can be obtained by mixing a fine ferrite powder of an average particle diameter of greater than 0.50 to 1.0 μm and a coarse ferrite powder of an average particle diameter of greater than 2.50 to 5.0 μm at ratio to incorporate the fine powder at a content ratio of 15-40 wt %.

Claims (1)

1. A ferrite magnetic powder for a bond magnet, which is a ferrite magnetic powder comprising strontium as a constituent element and that is a mixed powder obtained by mixing a fine powder of the ferrite of an average particle diameter of greater than 0.50 to 1.0 μm and a coarse powder of the ferrite of an average particle diameter of greater than 2.50 to 5.0 μm at a ratio to incorporate the fine powder at a content ratio of 15-40 wt. %.

Assignments (3)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 7, 2008
From: DOWA HOLDINGS CO., LTD.
To: DOWA ELECTRONICS MATERIALS CO., LTD.
Reel/Frame 020323/0715 →
CHANGE OF NAME Recorded Nov 5, 2007
From: DOWA MINING CO., LTD.
To: DOWA HOLDINGS CO., LTD.
Reel/Frame 020121/0161 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 22, 2004
From: SENDA, MASAYASU; SUENAGA, SHINICHI; AYABE, KEISUKE; SAKAI, TOSHIYUKI
To: DOWA MINING CO., LTD.; NIPPON BENGARA KOGYO CO., LTD.
Reel/Frame 015257/0950 →