Fujifilm Corporation

Dowa Electronics Materials Co., Ltd.

Norihito Kasada

Eiki Ozawa

Takuto Kurokawa

Tetsuya Kaneko

Atsushi Musha

Toshio Tada

Masahito Oyanagi

Yusuke Kaneko

Yuto Murata

So Matsuyama

Junya Sawada

Nobuhito Onozuka

Ryosuke Yumiyama

Toru Nakao

Naoki Sano

Yusuke Kagawa

Takahiro Iwamoto

Akinori Sugishima

Yujin Shibata

Takuro Sugiyama

Nagisa Yamasaki

Hidemasa Hosoda

Megumi Nakano

Shota Kamimura

Tomohide Ueyama

Kazuyuki Kitada

Yosuke Sumiya

Takashi Fujimoto

Tatsuo Ishikawa

Kenji Masada

Kengo Saito

Hirohisa Omoto

Yoshihiro Sawayashiki

Daisuke Abe

Masahide Sato

Yasushi Komori

Tadashi Kira

Junichi Nakamigawa

Isamu Watanabe

Yasuhiro Kawatani

Futoshi Nagashima

Tatsuya Yamashita

The magnetic tape includes: a non-magnetic support; and a magnetic layer containing a ferromagnetic powder, in which an arithmetic average roughness Ra measured on a surface of the magnetic layer is 1.5 nm or less, and standard deviation σ of the Ra in a width direction of the surface of the magnetic layer is 0.20 nm or less.

Magnetic tape, magnetic tape cartridge, and magnetic tape apparatus

The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder. A magnetic tape cartridge and a magnetic tape apparatus include the magnetic tape. An arithmetic average curvature Spc of a peak point specified in ISO 25178 on a surface of the magnetic layer is 0.30 (1/μm) or more and 0.70 (1/μm) or less, and standard deviation a of the Spc in a width direction of the surface of the magnetic layer is 0.15 (1/μm) or less.

The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder. A magnetic tape cartridge and a magnetic tape apparatus include the magnetic tape. A dale void volume Vvv specified in ISO 25178 on a surface of the magnetic layer is 0.100 nmor more and 0.350 nmor less, and standard deviation a of the Vvv in a width direction of the surface of the magnetic layer is 0.020 nmor less.

The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder. A magnetic tape cartridge and a magnetic tape apparatus include the magnetic tape. Svi obtained by measuring a surface of the magnetic layer with an atomic force microscope and by Equation A is 0.080 or more and 0.130 or less, and standard deviation σ of the Svi in a width direction of the surface of the magnetic layer is 0.010 or less. In Equation A, Sq is a root-mean-square height Sq specified in ISO 25178, Vv(h) is a void volume in a region where a load area ratio in a bearing curve is 80% or more and 100% or less, and A is a measurement region area.

In the magnetic tape, in a case where a maximum value of an absolute value of a difference between a servo band spacing obtained before storage in an environment of a temperature of 32° C. and relative humidity of 55% and a servo band spacing obtained after storage in the environment for a storage time T is set to A, and T is defined as 24 hours, 48 hours, 72 hours, 96 hours, or 120 hours, a medium life calculated by a linear function of A and a logarithm logT of T, that are derived from a value of A and a value of the logarithm logT of T obtained for each T is 3 years or longer. The medium life is T in a case where the A satisfies Equation 1: A=1.5−B.

Magnetic tape cartridge and magnetic recording and reproducing device

The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder. A magnetic tape cartridge and a magnetic tape apparatus include the magnetic tape. VIVA 0.1, which is a height that is obtained by measuring a surface of the magnetic layer with an atomic force microscope and at which a cross-sectional area is 0.1% with a measurement region area as 100%, is 5 nm or more and 10 nm or less, and standard deviation σ of the VIVA 0.1 in a width direction of the surface of the magnetic layer is 1.0 nm or less.

The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder. A magnetic tape cartridge and a magnetic tape apparatus include the magnetic tape. A core void volume Vvc specified in international organization for standardization (ISO) 25178 on a surface of the magnetic layer is 1.200 nmor more and 3.000 nmor less, and standard deviation σ of the Vvc in a width direction of the surface of the magnetic layer is 0.120 nmor less.

The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder. A magnetic tape cartridge and a magnetic tape apparatus include the magnetic tape. CS VIVA 0.1, which is a height that is obtained by measuring a surface of the magnetic layer with an atomic force microscope and at which a cutout length is 0.1% with a length of one side of a measurement region as 100%, is 4 nm or more and 10 nm or less, and standard deviation a of the CS VIVA 0.1 in a width direction of the surface of the magnetic layer is 1.0 nm or less.

The magnetic tape includes: a non-magnetic support; and a magnetic layer containing a ferromagnetic powder, in which an AlFeSil abrasion value measured on a surface of the magnetic layer is 20 μm or more and 50 μm or less, and standard deviation a of the AlFeSil abrasion value obtained in a width direction of the surface of the magnetic layer is 5.0 μm or less.

Magnetic tape with characterized AlFeSil abrasion value, magnetic tape cartridge, and magnetic tape apparatus

Provided is a magnetic tape apparatus in which the magnetic tape is run between a winding reel and a cartridge reel in a state where a tension is applied in a longitudinal direction, a maximum value of the tension is 0.50 N or more, the magnetic tape after being run in a state where the tension is applied is wound around the cartridge reel with a tension of 0.30 N or less applied in the longitudinal direction, and the number of recesses existing on a surface of the magnetic layer of the magnetic tape and having an equivalent circle diameter of 0.10 μm or more and less than 0.20 μm is 100 or more and 2000 or less per an area of 40 μm×40 μm.

Magnetic tape apparatus, magnetic tape, and magnetic tape cartridge

The magnetic tape includes: a non-magnetic support; and a magnetic layer containing a ferromagnetic powder, in which the number of recesses existing on a surface of the magnetic layer and having an equivalent circle diameter of 0.25 μm or more and 0.55 μm or less is 10 or more and 500 or less per an area of 40 μm×40 μm, and standard deviation a of the number of the recesses in a width direction of the surface of the magnetic layer is 50 or less.

Magnetic tape with characterized surface recesses, magnetic tape cartridge, and magnetic tape apparatus

The magnetic tape includes: a non-magnetic support; and a magnetic layer containing a ferromagnetic powder, in which a contact angle with 1-bromonaphthalene, which is measured on a surface of the magnetic layer, is 45.0° or more and 55.0° or less, and standard deviation σ of the contact angle in a width direction of the surface of the magnetic layer is 1.0° or less.

Provided is a magnetic tape apparatus. In a case where a maximum value of an absolute value of a difference between a servo band interval obtained before the following storage and a servo band interval obtained after the storage of N cycles, in which a predetermined storage is set as one cycle, is denoted by A, and a medium life is equal to or longer than 5 years, which is calculated by a linear function of A and a logarithm logT of T derived from a value of A and a value of the logarithm logT of a total storage time T of the storage of the N cycles, each of which is obtained by setting N as 1, 2, 3, 4, or 5. The medium life is T, in a case where A satisfies Expression a: A=1.5−B+C.

Magnetic tape apparatus

The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder. A magnetic tape cartridge and a magnetic tape apparatus include the magnetic tape. A protruding peak height Spk specified in ISO 25178 on a surface of the magnetic layer is 1.5 nm or more and 3.0 nm or less, and standard deviation σ of the Spk in a width direction of the surface of the magnetic layer is 0.5 nm or less.

Provided is a magnetic tape, in which, in an environment with a temperature of 23° C. and a relative humidity of 50%, an AlFeSil abrasion value° of a surface of the magnetic layer, which is measured at a tilt angle of 45° of an AlFeSil square bar, is 20 μm or more and 50 μm or less, and standard deviation of AlFeSil abrasion values of the surface of the magnetic layer, which are respectively measured at tilt angles of 0°, 15°, 30°, and 45° of the AlFeSil square bar, is 30 μm or less. The tilt angle of the AlFeSil square bar is an angle formed by a longitudinal direction of the AlFeSil square bar and a width direction of the magnetic tape. The magnetic tape includes a polyethylene naphthalate support having a Young's modulus in a width direction of 10000 MPa or more.

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Minami-ashigara, Japan

Norihito Kasada