公开(公告)号：US10026435B2

公开(公告)日：2018-07-17

申请号：US15241631

申请日：2016-08-19

申请人： FUJIFILM Corporation

发明人： Norihito Kasada ,  Masahito Oyanagi ,  Toshio Tada ,  Takuro Sugiyama

IPC分类号： G11B5/78 ,  G11B5/70 ,  G11B5/735 ,  G11B5/842

摘要： The magnetic tape has a magnetic layer containing ferromagnetic powder and binder on the surface on one side of a nonmagnetic support and has a backcoat layer containing nonmagnetic powder and binder on the surface on the other side of the nonmagnetic support, wherein the backcoat layer is less than or equal to 0.30 μm in thickness; and the logarithmic decrement as determined by a pendulum viscoelasticity test on the surface on the backcoat layer side of the magnetic tape is less than or equal to 0.060.

公开(公告)号：US10026434B2

公开(公告)日：2018-07-17

申请号：US15241297

申请日：2016-08-19

申请人： FUJIFILM Corporation

发明人： Masahito Oyanagi ,  Norihito Kasada ,  Toshio Tada ,  Takuro Sugiyama

IPC分类号： G11B5/78 ,  G11B5/70 ,  G11B5/708 ,  G11B5/842

摘要： The magnetic tape has a magnetic layer containing ferromagnetic powder and binder on a nonmagnetic support, wherein the centerline average surface roughness Ra as measured on the surface on the magnetic layer side of the magnetic tape is less than or equal to 1.8 nm, and the logarithmic decrement as determined by a pendulum viscoelasticity test on the surface on the magnetic layer side of the magnetic tape is less than or equal to 0.050.

公开(公告)号：US09875766B2

公开(公告)日：2018-01-23

申请号：US15141168

申请日：2016-04-28

申请人： FUJIFILM Corporation

发明人： Masahiko Mori

IPC分类号： G11B5/735 ,  G11B5/71 ,  G11B5/78

CPC分类号： G11B5/735 ,  G11B5/71 ,  G11B5/78

摘要： The magnetic tape has a nonmagnetic layer, a magnetic layer, and a backcoat layer; with one or both of the magnetic layer and nonmagnetic layer comprising at least one type of lubricant; with the backcoat layer comprising at least one type of lubricant; with a surface lubricant index as measured on a surface of the magnetic layer ranging from 1.00 to 4.00; and with a state of a presence of indentations on the surface of the magnetic layer satisfying condition 1 and condition 2: condition 1: a number of indentations greater than or equal to 5 nm and less than 10 nm in depth of 5 to 1,000 per 350 μm×260 μm area; and condition 2: a number of indentations greater than or equal to 10 nm in depth of less than or equal to 100 per 350 μm×260 μm area.

公开(公告)号：US20170372740A1

公开(公告)日：2017-12-28

申请号：US15624897

申请日：2017-06-16

申请人： FUJIFILM Corporation

发明人： Eiki OZAWA ,  Tetsuya KANEKO ,  Norihito KASADA

IPC分类号： G11B5/78 ,  G11B5/73 ,  G11B5/584 ,  G11B5/71 ,  G11B5/735 ,  G11B5/733

摘要： Provided is a magnetic tape in which the total thickness is equal to or smaller than 5.30 μm, the magnetic layer includes a timing-based servo pattern, a magnetic layer surface Ra is equal to or smaller than 1.8 nm, the magnetic layer includes fatty acid ester, a full width at half maximum of spacing distribution measured by optical interferometry regarding the surface of the magnetic layer before performing vacuum heating with respect to the magnetic tape is greater than 0 nm and equal to or smaller than 7.0 nm, a full width at half maximum of spacing distribution measured after performing the vacuum heating is greater than 0 nm and equal to or smaller than 7.0 nm, and a difference between a spacing measured after performing the vacuum heating and a spacing measured before performing the vacuum heating is greater than 0 nm and equal to or smaller than 8.0 nm.

公开(公告)号：US20170372736A1

公开(公告)日：2017-12-28

申请号：US15628814

申请日：2017-06-21

申请人： FUJIFILM Corporation

发明人： Tetsuya KANEKO ,  Norihito KASADA ,  Eiki OZAWA

IPC分类号： G11B5/588 ,  G11B5/78 ,  G11B5/70

CPC分类号： G11B5/588 ,  G11B5/584 ,  G11B5/70 ,  G11B5/70678 ,  G11B5/7085 ,  G11B5/78

摘要： The magnetic tape includes a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binder on the non-magnetic support, in which the total thickness of the magnetic tape is equal to or smaller than 5.30 μm, the magnetic layer includes a timing-based servo pattern, a center line average surface roughness Ra measured regarding a surface of the magnetic layer is equal to or smaller than 1.8 nm, the ferromagnetic powder is ferromagnetic hexagonal ferrite powder, the magnetic layer includes an abrasive, and a tilt cos θ of the ferromagnetic hexagonal ferrite powder with respect to a surface of the magnetic layer acquired by cross section observation performed by using a scanning transmission electron microscope is 0.85 to 1.00.

公开(公告)号：US20170316801A1

公开(公告)日：2017-11-02

申请号：US15490924

申请日：2017-04-19

申请人： FUJIFILM CORPORATION

发明人： Yosuke SUMIYA

IPC分类号： G11B15/61 ,  G11B5/78

CPC分类号： G11B15/615 ,  G11B5/78 ,  G11B23/044 ,  G11B23/107

摘要： A recording tape cartridge includes: a reel including a reel hub having an outer diameter of an upper end portion thereof is smaller than that of a lower end portion thereof, and a lower flange in which plural through holes are radially formed and inclined surfaces are formed at one edge portion and the other edge portion of each of the through holes, the inclined surfaces are directed to a flange circumferential direction. An inclination angle with respect to a reel rotation axis of the inclined surface at the one edge portion, which is directed in a rotational direction of the reel, when a recording tape is wound on the reel, is larger than an inclination angle with respect to the reel rotation axis of the inclined surface of the other edge portion, which is directed in the rotational direction of the reel when the recording tape is led out of the reel.

公开(公告)号：US20170287517A1

公开(公告)日：2017-10-05

申请号：US15475615

申请日：2017-03-31

申请人： FUJIFILM Corporation

发明人： Yoichi HOSOYA ,  Masashi SHIRATA

IPC分类号： G11B5/706 ,  G11B5/78 ,  G11B5/714

CPC分类号： G11B5/70615 ,  B82Y25/00 ,  G11B5/70678 ,  G11B5/714 ,  G11B5/78 ,  H01F1/0063 ,  H01F1/11

摘要： Hexagonal ferrite powder has an average particle size falling within a range of 10 nm to 50 nm, a switching field distribution SFD23° C. measured at a temperature of 23° C. that is less than or equal to 0.80, and a ratio of a switching field distribution SFD−190° C. that is measured at a temperature of −190° C. to the SFD23° C. (SFD−190° C./SFD23° C.) that is greater than 0.80.

公开(公告)号：US09767835B2

公开(公告)日：2017-09-19

申请号：US15054887

申请日：2016-02-26

申请人： HITACHI MAXELL, LTD.

发明人： Kenji Tanaka ,  Masao Fujita ,  Sadamu Kuse

IPC分类号： G11B5/71 ,  G11B5/714 ,  G11B5/738 ,  G11B5/706 ,  G11B5/78

CPC分类号： G11B5/71 ,  G11B5/70615 ,  G11B5/70626 ,  G11B5/714 ,  G11B5/738 ,  G11B5/78

摘要： A magnetic recording medium of the present invention is a magnetic recording medium including a non-magnetic substrate; a non-magnetic layer that is formed on one of principal surfaces of the non-magnetic substrate and contains a non-magnetic powder, a binder, and a lubricant; and a magnetic layer that is formed on a principal surface of the non-magnetic layer opposite to the non-magnetic substrate and contains a magnetic powder and a binder. The magnetic powder has an average particle size between 10 nm and 35 nm inclusive. The lubricant is migratable to the magnetic layer and forms a lubricant layer on a surface of the magnetic layer when a pressure is applied to the magnetic layer. When spacing of the surface of the magnetic layer before and after washing the lubricant with n-hexane is measured with a TSA (Tape Spacing Analyzer), the value of the spacing after washing is 3 to 10 nm, and the value of the spacing before washing is 1 to 5 nm smaller than the value of the spacing after washing.

公开(公告)号：US09633676B2

公开(公告)日：2017-04-25

申请号：US14710173

申请日：2015-05-12

申请人： Sigma Pro Ltd. LLC

发明人： Tyson York Winarski

IPC分类号： G11B5/65 ,  G11B5/17 ,  B82Y10/00 ,  G11B5/706 ,  G11B5/74 ,  G11B5/78 ,  G11B5/82 ,  G11B5/127

CPC分类号： G11B5/17 ,  B82Y10/00 ,  G11B5/1278 ,  G11B5/65 ,  G11B5/706 ,  G11B5/746 ,  G11B5/78 ,  G11B5/82 ,  Y10S977/943 ,  Y10T29/49

摘要： A magnetic storage medium is formed of magnetic nanoparticles that are encapsulated within nanotubes (e.g., carbon nanotubes).

公开(公告)号：US09601146B2

公开(公告)日：2017-03-21

申请号：US14753227

申请日：2015-06-29

申请人： FUJIFILM Corporation

发明人： Norihito Kasada ,  Masahito Oyanagi ,  Toshio Tada

IPC分类号： G11B5/708 ,  G11B5/78 ,  G11B5/70 ,  G11B5/714

CPC分类号： G11B5/78 ,  G11B5/70 ,  G11B5/714

摘要： An aspect of the present invention relates to a magnetic tape comprising a magnetic layer comprising ferromagnetic powder and binder on a nonmagnetic support, wherein ΔSFD in a longitudinal direction of the magnetic tape as calculated with Equation 1 ranges from 0.35 to 1.50: ΔSFD=SFD25° C.−SFD−190° C.  Equation 1 wherein, in Equation 1, SFD25° C. denotes a switching field distribution SFD as measured in the longitudinal direction of the magnetic tape in an environment with a temperature of 25° C., and SFD−190° C. denotes a switching field distribution SFD as measured in the longitudinal direction of the magnetic tape in an environment with a temperature of −190° C.