公开(公告)号：US10074396B2

公开(公告)日：2018-09-11

申请号：US15264988

申请日：2016-09-14

Applicant: SHOWA DENKO K.K.

Inventor： Eishin Yamakawa ,  Katsuaki To ,  Saeko Hayase

IPC: G11B5/65 ,  G11B19/28 ,  G11B21/10 ,  G11B5/72 ,  G11B5/725

CPC classification number: G11B19/28 ,  G11B5/72 ,  G11B5/725 ,  G11B21/106

Abstract: In a magnetic recording medium of the present invention, an outermost surface of a protective layer 3 on a lubricant layer 4 side contains carbon and nitrogen in a range of 50 atomic % to 90 atomic %, and the lubricant layer 4 is formed by being in contact with the outermost surface, contains compounds A to C represented in the below general formulas (1) to (3) described below, and has a film thickness of 0.5 nm to 2 nm. R1-C6H4OCH2CH(OH)CH2OCH2—R2-CH2OCH2CH(OH)CH2OH   (1), CH2(OH)CH(OH)CH2OCH2CF2CF2(OCF2CF2CF2)mOCF2CF2CH2OCH2CH(OH)CH2OH   (2), HOCH2CF2CF2O(CF2CF2CF2O)sCF2CF2CH2OCH2CH(OH)CH2OH   (3)

公开(公告)号：US11322176B2

公开(公告)日：2022-05-03

申请号：US16896401

申请日：2020-06-09

Applicant: SHOWA DENKO K.K. ,  The School Corporation Kansai University

Inventor： Hiroshi Tani ,  Hiroshi Sakai ,  Eishin Yamakawa ,  Kazuki Shindo

IPC: G11B5/84 ,  G11B5/851 ,  C08G65/00 ,  G11B5/85 ,  G11B5/725

Abstract: A method of manufacturing a magnetic recording medium forms an unfinished product including a magnetic recording layer and a protection layer that are successively formed on a substrate, and forms a lubricant layer on the protection layer of the unfinished product. The lubricant layer is formed by coating a first organic fluorine compound on the protection layer of the unfinished product, and supplying a gas, including a second organic fluorine compound, onto the protection layer of the unfinished product, and decomposing the second organic fluorine compound by Townsend discharge and ultraviolet ray irradiation. The protection layer includes carbon, and the first organic fluorine compound includes a functional group at a terminal thereof.

公开(公告)号：US10888895B2

公开(公告)日：2021-01-12

申请号：US15895114

申请日：2018-02-13

Applicant: SHOWA DENKO K.K. ,  A SCHOOL CORPORATION KANSAI UNIVERSITY

Inventor： Hiroshi Tani ,  Hiroshi Sakai ,  Eishin Yamakawa ,  Kazuki Shindo

IPC: C23C16/48 ,  B05D1/00 ,  G11B5/84 ,  G03F7/00 ,  C23C16/503 ,  G11B5/725 ,  B29C33/58 ,  B29C33/62 ,  B29C33/38 ,  G11B5/72

Abstract: A film production method for producing a thin film on a surface of a workpiece, including the steps of: disposing the workpiece in a chamber; supplying a process gas into the chamber with the inside of the chamber being maintained at a predetermined pressure; applying a light having an energy between 3 eV and 10 eV to the surface of the workpiece to cause a photoelectron to be emitted from the surface of the workpiece; and applying an AC electric field to the surface of the workpiece, wherein the AC electric field has an electric field intensity causing a Townsend discharge to occur without generating a glow discharge plasma.

公开(公告)号：US10199064B2

公开(公告)日：2019-02-05

申请号：US15044529

申请日：2016-02-16

Applicant: SHOWA DENKO K.K.

Inventor： Yoshihiko Maruyama ,  Selvaraj Aanandha ,  Yuan Ai Khoo ,  Satoru Nakamura ,  Hiromitsu Tanuma ,  Eishin Yamakawa

IPC: G11B5/72 ,  G11B5/725 ,  G11B5/82

Abstract: A magnetic recording medium which is capable of effectively preventing a surface thereof from being contaminated, and is capable of preventing a contaminant thereon from adhering (being transferred) to a magnetic head, and a magnetic recording and reproducing apparatus including the magnetic recording medium are provided,A carbon protective layer of the magnetic recording medium is nitrided, and as a lubricant a compound A expressed by the following General Formula (1) and a compound B expressed by the following General Formula (2) are mixed and used. R1—C6H4OCH2CH(OH)CH2OCH2—R2—CH2OCH2CH(OH)CH2OH  (1) CH2(OH)CH(OH)CH2OCH2CF2CF2(OCF2CF2CF2)mOCF2CF2CH2OCH2CH(OH)CH2OH  (2)

公开(公告)号：US09640213B2

公开(公告)日：2017-05-02

申请号：US14935529

申请日：2015-11-09

Applicant: SHOWA DENKO K.K. ,  JAPAN ATOMIC ENERGY AGENCY

Inventor： Kota Hasegawa ,  Takahiro Ukai ,  Eishin Yamakawa ,  Shiro Entani ,  Seiji Sakai

IPC: G11B5/66 ,  G11B5/72 ,  G11B5/82

CPC classification number: G11B5/72 ,  G11B5/66 ,  G11B5/82

Abstract: A perpendicular magnetic recording medium includes a perpendicular magnetic layer provided above a nonmagnetic substrate, and a protection layer provided on the perpendicular magnetic layer. The perpendicular magnetic layer has an hcp structure, and includes stacked layers having a (0002) crystal plane oriented parallel to a surface of the nonmagnetic substrate. An uppermost layer amongst the stacked layers includes polycrystal grains selected from a CoCr-base alloy, a CoPt-base alloy, a CoCrPt-base alloy, and a CoPtCr-base alloy. The protection layer makes contact with the uppermost layer of the perpendicular magnetic layer, and includes a single graphene layer or a graphene stack, and an amorphous carbon layer. The single graphene layer or the graphene stack is bonded in parallel to a (0002) crystal plane of the polycrystal grains.