-
公开(公告)号：US20210241792A1
公开(公告)日：2021-08-05
申请号：US17160535
申请日：2021-01-28
Applicant: FUJIFILM Corporation
Inventor： Takuto KUROKAWA , Naoki SANO , Norihito KASADA
Abstract: The magnetic tape in which a difference (S0.1−S1.6) between a spacing S0.1 and a spacing S1.6 obtained after n-hexane cleaning on a surface of the magnetic layer is equal to or less than 32 nm. The S0.1 is a value obtained as a spacing under a pressing force of 0.1 atm from a relational expression between a pressure and a spacing obtained by performing a spacing measurement on the surface of the magnetic layer by an optical interference method under a pressing force of each of a plurality of different pressures after the n-hexane cleaning, and S1.6 is a spacing measured on the surface of the magnetic layer by the optical interference method under the pressing force of 1.6 atm after the n-hexane cleaning.
-
公开(公告)号：US20190304497A1
公开(公告)日：2019-10-03
申请号：US16367918
申请日：2019-03-28
Applicant: FUJIFILM Corporation
Inventor： Takuto KUROKAWA , Eiki OZAWA
Abstract: The magnetic recording medium includes a non-magnetic support; and a magnetic layer including a ferromagnetic powder and a binding agent on the non-magnetic support, in which a center line average surface roughness Ra measured regarding a surface of the magnetic layer is 1.0 nm to 1.6 nm, and a difference (Safter−Sbefore) between a spacing Safter measured by optical interferometry regarding the surface of the magnetic layer after ethanol cleaning and a spacing Sbefore measured by optical interferometry regarding the surface of the magnetic layer before ethanol cleaning is greater than 0 nm and equal to or smaller than 6.0 nm.
-
公开(公告)号：US20170372741A1
公开(公告)日：2017-12-28
申请号：US15625428
申请日：2017-06-16
Applicant: FUJIFILM Corporation
Inventor： Takuto KUROKAWA , Eiki OZAWA , Norihito KASADA
Abstract: Provided is a magnetic tape in which a thickness of a back coating layer is equal to or smaller than 0.20 μm, a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the back coating layer at a photoelectron take-off angle of 10 degrees, is equal to or greater than 35 atom %, full widths at half maximum of spacing distribution measured by optical interferometry regarding the surface of the back coating layer before and after performing a vacuum heating with respect to the magnetic tape are respectively greater than 0 nm and equal to or smaller than 10.0 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：US20210398555A1
公开(公告)日：2021-12-23
申请号：US17338688
申请日：2021-06-04
Applicant: FUJIFILM Corporation
Inventor： So MATSUYAMA , Norihito KASADA , Takuto KUROKAWA
Abstract: The magnetic recording and reproducing device includes a magnetic recording medium, a recording element, and a reproducing element. The recording element is an inductive recording element having a first magnetic pole which generates a magnetic field, and a second magnetic pole which is spaced apart from the first magnetic pole with a write gap interposed therebetween, a tip width of the first magnetic pole is substantially the same as a tip width of the second magnetic pole, and a reproducing element width of the reproducing element is 0.5 μm to 0.8 μm. The magnetic recording medium has a non-magnetic support, and a magnetic layer containing a ferromagnetic powder, and the number of recesses, which are present in a surface of the magnetic layer and have an equivalent circle diameter of 0.20 μm to 0.50 μm, is 10 to 500 per area of 40 μm×40 μm.
-
公开(公告)号：US20210090602A1
公开(公告)日：2021-03-25
申请号：US17025092
申请日：2020-09-18
Applicant: FUJIFILM Corporation
Inventor： Naoki SANO , Takuto KUROKAWA , Eiki OZAWA , Norihito KASADA , Megumi NAKANO
Abstract: The magnetic recording medium includes: a non-magnetic support; a magnetic layer that includes ferromagnetic powder on one surface side of the non-magnetic support; and a back coating layer that includes non-magnetic powder on the other surface side of the non-magnetic support, in which a difference between a spacing measured on a surface of the back coating layer by optical interferometry under a pressure of 0.5 atm after n-hexane cleaning and a spacing measured on the surface of the back coating layer by optical interferometry under a pressure of 13.5 atm after n-hexane cleaning is 12 nm or more.
-
Patent Agency Ranking
公开(公告)号：US20200279580A1
公开(公告)日：2020-09-03
申请号：US16802768
申请日：2020-02-27
Applicant: FUJIFILM Corporation
Inventor： Naoki SANO , Eiki OZAWA , Norihito KASADA , Takuto KUROKAWA
Abstract: The magnetic recording medium includes: a non-magnetic support; and a magnetic layer including ferromagnetic powder, in which a difference (S0.5−S13.5) between a spacing S0.5 measured on a surface of the magnetic layer by optical interferometry after n-hexane cleaning under a pressure of 0.5 atm and a spacing S13.5 measured on the surface of the magnetic layer by optical interferometry after n-hexane cleaning under a pressure of 13.5 atm is 9.0 nm or more.
-
公开(公告)号：US20200227081A1
公开(公告)日：2020-07-16
申请号：US16832788
申请日：2020-03-27
Applicant: FUJIFILM Corporation
Inventor： Hidemasa HOSODA , Takuto KUROKAWA , Norihito KASADA , Takahiro IWAMOTO
Abstract: Provided are a magnetic tape comprising a magnetic layer containing a ferromagnetic powder and a binding agent on a non-magnetic support, in which the magnetic layer contains an oxide abrasive, an average particle diameter of the oxide abrasive obtained from a secondary ion image acquired by irradiating a surface of the magnetic layer with a focused ion beam is greater than 0.08 μm and 0.14 μm or smaller, and an absolute value ΔN of a difference between a refractive index Nxy measured with respect to an in-plane direction of the magnetic layer and a refractive index Nz measured with respect to a thickness direction of the magnetic layer is 0.25 to 0.40, and a magnetic recording and reproducing device including the magnetic tape.
-
公开(公告)号：US20190304499A1
公开(公告)日：2019-10-03
申请号：US16368271
申请日：2019-03-28
Applicant: FUJIFILM Corporation
Inventor： Takuto KUROKAWA , Eiki OZAWA
Abstract: The magnetic tape includes a non-magnetic support; a magnetic layer including a ferromagnetic powder and a binding agent on one surface of the non-magnetic support; and a back coating layer including a non-magnetic powder and a binding agent on the other surface of the non-magnetic support, in which a center line average surface roughness Ra measured regarding a surface of the back coating layer is equal to or smaller than 7.0 nm, and a difference (Safter−Sbefore) between a spacing Safter measured by optical interferometry regarding the surface of the back coating layer after ethanol cleaning and a spacing Sbefore measured by optical interferometry regarding the surface of the back coating layer before ethanol cleaning is greater than 0 nm and equal to or smaller than 15.0 nm.
-
公开(公告)号：US20190027179A1
公开(公告)日：2019-01-24
申请号：US16037681
申请日：2018-07-17
Applicant: FUJIFILM Corporation
Inventor： Eiki OZAWA , Norihito KASADA , Toshio TADA , Takuto KUROKAWA
Abstract: The magnetic recording medium includes a magnetic layer which contains ferromagnetic hexagonal ferrite powder and a binder, in which the magnetic layer contains an abrasive and a fatty acid ester, Int (110)/Int (114) of a crystal structure of the hexagonal ferrite, determined by performing XRD analysis on the magnetic layer by using an In-Plane method, is equal to or higher than 0.5 and equal to or lower than 4.0, a squareness ratio of the magnetic recording medium in a vertical direction is equal to or higher than 0.65 and equal to or lower than 1.00, FWHMbefore and FWHMafter is greater than 0 nm and equal to or smaller than 7.0 nm, and a difference between spacings measured within a surface of the magnetic layer by an optical interference method before and after the heating in a vacuum is greater than 0 nm and equal to or smaller than 8.0 nm.
-
公开(公告)号：US20190027174A1
公开(公告)日：2019-01-24
申请号：US16037596
申请日：2018-07-17
Applicant: FUJIFILM Corporation
Inventor： Toshio TADA , Norihito KASADA , Eiki OZAWA , Takuto KUROKAWA
Abstract: Provided is a magnetic tape in which an Ra measured regarding a surface of a magnetic layer is equal to or smaller than 1.8 nm, Int(110)/Int(114) of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical squareness ratio of the magnetic tape is 0.65 to 1.00, the back coating layer includes one or more kinds of component selected from the group consisting of fatty acid and fatty acid amide, and a C—H derived C concentration calculated from a C—H peak area ratio of C1s spectra obtained by X-ray photoelectron spectroscopic analysis performed on the surface of the back coating layer at a photoelectron take-off angle of 10 degrees is equal to or greater than 35 atom %.
-
-
-
-
-
-
-
-
-
Search Results
35
records
(took 0.019 seconds)
