公开(公告)号：US10770207B2

公开(公告)日：2020-09-08

申请号：US14233286

申请日：2013-03-08

Applicant: NITTO DENKO CORPORATION

Inventor： Katsuya Kume ,  Toshiaki Okuno ,  Izumi Ozeki ,  Tomohiro Omure ,  Takashi Ozaki ,  Keisuke Taihaku ,  Takashi Yamamoto

IPC: H01F1/053 ,  B22F1/00 ,  H01F1/057 ,  H01F1/08 ,  B22F3/18 ,  B22F7/04 ,  C22C38/00 ,  H01F41/02

Abstract: There are provided a rare-earth permanent magnet and a manufacturing method of a rare-earth permanent magnet capable of preventing deterioration of magnet properties. In the method, magnet material is milled into magnet powder. Next, a mixture 12 is prepared by mixing the magnet powder and a binder, and the mixture 12 is formed into a sheet-like shape to obtain a green sheet 14. Thereafter, magnetic field orientation is performed to the green sheet 14, which is then held for several hours in a non-oxidizing atmosphere at a pressure higher than normal atmospheric pressure, at 200 through 900 degrees Celsius for calcination. Thereafter, the calcined green sheet 14 is sintered at a sintering temperature. Thereby a permanent magnet 1 is manufactured.

公开(公告)号：US10269475B2

公开(公告)日：2019-04-23

申请号：US15118116

申请日：2014-02-12

Applicant: NITTO DENKO CORPORATION

Inventor： Izumi Ozeki ,  Katsuya Kume ,  Toshiaki Okuno ,  Takashi Ozaki ,  Tomohiro Omure ,  Keisuke Taihaku ,  Takashi Yamamoto

IPC: H01F41/02 ,  H01F1/053 ,  C22C38/00 ,  B22F3/10 ,  B22F3/22 ,  B22F5/00 ,  B22F9/04 ,  C22C1/04 ,  H01F1/057 ,  C22C33/02

Abstract: Provided are a rare-earth permanent magnet whose magnet density after sintering is very high and a method for manufacturing a rare-earth permanent magnet. Thus, a magnet raw material is milled into magnet powder, and then, a compound 12 is formed by mixing the magnet powder thus milled with a binder. Next, the compound 12 thus formed is subjected to a hot-melt molding onto a supporting substrate 13 so as to form a green sheet 14 molded to a sheet-like shape. Thereafter, while the green sheet 14 thus molded is softened by heating, magnetic field orientation is carried out by applying a magnetic field to the green sheet 14 thus heated; and further, the green sheet 14 having been subjected to the magnetic field orientation is calcined by a vacuum sintering, which is further followed by a pressure sintering to produce a permanent magnet 1.

公开(公告)号：US20160141100A1

公开(公告)日：2016-05-19

申请号：US15007318

申请日：2016-01-27

Applicant: NITTO DENKO CORPORATION

Inventor： Keisuke TAIHAKU ,  Katsuya Kume ,  Toshiaki Okuno ,  Izumi Ozeki ,  Tomohiro Omure ,  Takashi Ozaki

IPC: H01F41/02 ,  B22F1/02 ,  C22C38/00 ,  B22F5/00 ,  H01F1/053 ,  B22F1/00 ,  B22F3/10

CPC classification number: H01F1/0536 ,  B22F1/0062 ,  B22F1/02 ,  B22F3/02 ,  B22F3/1021 ,  B22F3/16 ,  B22F5/006 ,  B22F2001/0066 ,  B22F2003/248 ,  B22F2201/01 ,  B22F2301/45 ,  B22F2302/45 ,  B22F2998/10 ,  B22F2999/00 ,  C22C38/002 ,  C22C38/005 ,  C22C2202/02 ,  H01F1/06 ,  H01F1/42 ,  H01F41/0266 ,  B22F9/04 ,  B22F3/10

Abstract: There are provided a rare-earth permanent magnet and a manufacturing method thereof capable of preventing deterioration of magnet properties. In the method, magnet material is milled into magnet powder. Next, a mixture is prepared by mixing the magnet powder and a binder made of long-chain hydrocarbon and/or of a polymer or a copolymer consisting of monomers having no oxygen atoms. Next, the mixture is formed into a sheet-like shape so as to obtain a green sheet. After that, the green sheet is held for a predetermined length of time at binder decomposition temperature in a non-oxidizing atmosphere so as to remove the binder by causing depolymerization reaction or the like to the binder, which turns into monomer. The green sheet from which the binder has been removed is sintered by raising temperature up to sintering temperature. Thereby a permanent magnet 1 is obtained.