Magnetic tape having controlled surface properties of the magnetic layer and method of manufacturing the same
First Claim
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1. A magnetic tape,which comprises a nonmagnetic layer comprising nonmagnetic powder and binder on a nonmagnetic support, and comprises a magnetic layer comprising ferromagnetic powder and binder on the nonmagnetic layer, wherein:
- the combined thickness of the magnetic layer and the nonmagnetic layer is less than or equal to 0.80 μ
m;
the logarithmic decrement as determined by a pendulum viscoelasticity test on a surface on the magnetic layer side of the magnetic tape is greater than or equal to 0.010 but less than or equal to 0.050;
the coefficient of friction as measured on a base portion of the surface on the magnetic layer side is less than or equal to 0.35; and
the logarithmic decrement is determined by the following method;
securing a measurement sample of the magnetic tape with the measurement surface, which is the surface on the magnetic layer side, facing upward on a substrate in a pendulum viscoelasticity tester;
disposing a columnar cylinder edge which is 4 mm in diameter and equipped with a pendulum 13 g in weight on the measurement surface of the measurement sample such that the long axis direction of the columnar cylinder edge runs parallel to the longitudinal direction of the measurement sample;
raising the surface temperature of the substrate on which the measurement sample has been positioned at a rate of less than or equal to 5°
C./min up to 80°
C.;
inducing initial oscillation of the pendulum;
monitoring the displacement of the pendulum while it is oscillating to obtain a displacement-time curve for a measurement interval of greater than or equal to 10 minutes; and
obtaining the logarithmic decrement Δ
from the following equation;
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Abstract
The magnetic tape has a nonmagnetic layer containing nonmagnetic powder and binder on a nonmagnetic support, and has a magnetic layer containing ferromagnetic powder and binder on the nonmagnetic layer, wherein the combined thickness of the magnetic layer and the nonmagnetic layer is less than or equal to 0.80 μm; 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 and the coefficient of friction as measured on a base portion of the surface on the magnetic layer side is less than or equal to 0.35.
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Citations
17 Claims
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1. A magnetic tape,
which comprises a nonmagnetic layer comprising nonmagnetic powder and binder on a nonmagnetic support, and comprises a magnetic layer comprising ferromagnetic powder and binder on the nonmagnetic layer, wherein: -
the combined thickness of the magnetic layer and the nonmagnetic layer is less than or equal to 0.80 μ
m;the logarithmic decrement as determined by a pendulum viscoelasticity test on a surface on the magnetic layer side of the magnetic tape is greater than or equal to 0.010 but less than or equal to 0.050; the coefficient of friction as measured on a base portion of the surface on the magnetic layer side is less than or equal to 0.35; and the logarithmic decrement is determined by the following method; securing a measurement sample of the magnetic tape with the measurement surface, which is the surface on the magnetic layer side, facing upward on a substrate in a pendulum viscoelasticity tester; disposing a columnar cylinder edge which is 4 mm in diameter and equipped with a pendulum 13 g in weight on the measurement surface of the measurement sample such that the long axis direction of the columnar cylinder edge runs parallel to the longitudinal direction of the measurement sample; raising the surface temperature of the substrate on which the measurement sample has been positioned at a rate of less than or equal to 5°
C./min up to 80°
C.;inducing initial oscillation of the pendulum; monitoring the displacement of the pendulum while it is oscillating to obtain a displacement-time curve for a measurement interval of greater than or equal to 10 minutes; and obtaining the logarithmic decrement Δ
from the following equation; - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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Specification
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Current AssigneeFujifilm Corporation (Fujifilm Holdings Corporation)
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Original AssigneeFujifilm Corporation (Fujifilm Holdings Corporation)
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InventorsKasada, Norihito
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Primary Examiner(s)Bernatz, Kevin M
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Application NumberUS15/241,286Publication NumberTime in Patent Office697 DaysField of SearchNoneUS Class CurrentCPC Class CodesG11B 5/70 on a base layerG11B 5/7085 non-magnetic abrasive parti...G11B 5/78 Tape carriersG11B 5/842 Coating a support with a li...
