Fujifilm Corporation

Takuto Kurokawa

Norihito Kasada

Eiki Ozawa

Toshio Tada

Naoki Sano

So Matsuyama

Yujin Shibata

Masahito Oyanagi

Takahiro Iwamoto

Hidemasa Hosoda

Megumi Nakano

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, 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

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.

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 0.2 μm or greater and less than 0.5 μm. In the magnetic recording medium, the number of recesses, which are present in a surface of the magnetic layer and have an equivalent circle diameter of 0.10 μm or greater and less than 0.20 μm, is 100 to 2,000 per area of 40 μm×40 μm.

Magnetic recording and reproducing device

The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder, in which an edge portion Ra which is an arithmetic average roughness Ra measured at an edge portion of a surface of the magnetic layer is 1.50 nm or less, a central portion Ra which is an arithmetic average roughness Ra measured at a central portion of the surface of the magnetic layer is 0.30 nm to 1.30 nm, and a Ra ratio (central portion Ra/edge portion Ra) is 0.75 to 0.95.

Magnetic tape, magnetic tape cartridge, and magnetic tape device

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 difference (S&#x2212;S) between a spacing Smeasured by optical interferometry regarding a surface of the magnetic layer under a pressing force of 0.5 atm after n-hexane cleaning and a spacing Smeasured by optical interferometry regarding the surface of the magnetic layer under a pressing force of 13.5 atm after n-hexane cleaning is equal to or smaller than 3.0 nm, and a magnetic recording and reproducing device including this magnetic recording medium.

Magnetic recording medium and magnetic recording and reproducing device

The magnetic tape in which a difference (S&#x2212;S) between a spacing Sand a spacing Sobtained after n-hexane cleaning on a surface of the magnetic layer is equal to or less than 32 nm. The Sis 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 Sis 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.

Magnetic tape having characterized magnetic layer, magnetic tape cartridge, and magnetic tape apparatus

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 &#x3bc;m and 0.14 &#x3bc;m or smaller, and an absolute value &#x394;N 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.

Magnetic tape having characterized magnetic layer and magnetic recording and reproducing device

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 0.04 &#x3bc;m to 0.08 &#x3bc;m, and an absolute value &#x394;N 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.

The magnetic recording medium including: 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 (S&#x2212;S) between a spacing Smeasured by optical interferometry regarding the surface of the magnetic layer after methyl ethyl ketone cleaning and a spacing Smeasured by optical interferometry regarding the surface of the magnetic layer before methyl ethyl ketone cleaning is greater than 0 nm and equal to or smaller than 15.0 nm.

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 &#x3bc;m to 0.8 &#x3bc;m. 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 &#x3bc;m to 0.50 &#x3bc;m, is 10 to 500 per area of 40 &#x3bc;m&#xd7;40 &#x3bc;m.

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.

Magnetic recording medium having characterized back coat and magnetic recording and reproducing apparatus

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 3 nm or less.

Magnetic recording medium having characterized back coating layer and magnetic recording and reproducing apparatus

The magnetic recording medium includes: a non-magnetic support; and a magnetic layer including ferromagnetic powder, in which a difference (S&#x2212;S) between a spacing Smeasured on a surface of the magnetic layer by optical interferometry after n-hexane cleaning under a pressure of 0.5 atm and a spacing Smeasured 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.

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Minami-ashigara, Japan

Takuto Kurokawa