Magnetic recording medium
First Claim
1. A magnetic recording medium comprising:
- a lower layer comprising a nonmagnetic powder, and a binder and an upper magnetic layer having a magnetic layer surface and comprising a ferromagnetic powder, a binder and at least one abrasives material provided on a nonmagnetic support in this order, wherein said abrasive material has a plurality of abrasive particles, the number of abrasive particles X present on said magnetic layer surface, counted using a scanning electron microscope at 20,000 times magnification, satisfies the relation 0.2≦
X≦
1.2 (particles/μ
m2), and when the number of pairs of abrasive particles satisfying the relation L≦
2K (where K denotes the mean particle diameter of the abrasive, measuring using the scanning electron microscope at 20,000 times magnification, and L denotes the distance from the center of gravity of one of the abrasive particles to the center of gravity of to other abrasive particle, measured using the scanning electron microscope at 20,000 times magnification) is denoted as Y (particles/μ
m2), Y/X is equal to or less than 2.
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Accused Products
Abstract
Provided is a particulate magnetic recording medium with good output at high frequency, yielding a low coefficient of friction, and having good running properties, in particular, a magnetic recording medium affording good electromagnetic characteristics and good repeat durability in recording and reproducing at a high-density. The magnetic recording medium comprises a lower layer comprising a nonmagnetic powder and a binder and an upper magnetic layer comprising a ferromagnetic powder, a binder and at least one abrasives provided on a nonmagnetic support in this order. The number of abrasive particles present on said magnetic layer surface satisfied the relation 0.2≦X≦1.2 (particles/μm2). When the number of pairs of abrasive particles satisfying the relation L≦2K (where K denotes the mean particle diameter of the abrasive and L denotes the distance from the center of gravity of one of the abrasive particles to the center of gravity of the other abrasive particle) is denoted as Y (particles/μm2), Y/X is equal to or less than 2.
102 Citations
20 Claims
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1. A magnetic recording medium comprising:
-
a lower layer comprising a nonmagnetic powder, and a binder and an upper magnetic layer having a magnetic layer surface and comprising a ferromagnetic powder, a binder and at least one abrasives material provided on a nonmagnetic support in this order, wherein said abrasive material has a plurality of abrasive particles, the number of abrasive particles X present on said magnetic layer surface, counted using a scanning electron microscope at 20,000 times magnification, satisfies the relation 0.2≦
X≦
1.2 (particles/μ
m2), andwhen the number of pairs of abrasive particles satisfying the relation L≦
2K (where K denotes the mean particle diameter of the abrasive, measuring using the scanning electron microscope at 20,000 times magnification, and L denotes the distance from the center of gravity of one of the abrasive particles to the center of gravity of to other abrasive particle, measured using the scanning electron microscope at 20,000 times magnification) is denoted as Y (particles/μ
m2), Y/X is equal to or less than 2.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification