Magnetic recording medium and method of manufacturing the same
First Claim
Patent Images
1. A magnetic recording medium comprising a nonmagnetic layer containing a nonmagnetic powder and a binder and a magnetic layer containing a ferromagnetic powder and a binder in this order on a nonmagnetic support, whereinthe magnetic layer comprises a nonmagnetic powder of which coefficient of variation CV of a particle size distribution as denoted by the following formula (1):
-
CV(%)=σ
/φ
×
100
(1)is less than 20 percent,the nonmagnetic powder contained in the magnetic layer is silica powder,the magnetic layer further comprises an inorganic powder other than the silica powder, with a Mohs'"'"' hardness of equal to or higher than 6,the magnetic layer contains no carbon black, andthe magnetic layer has a thickness being equal to or less than 0.1 μ
m and falling within a range of 1.1≦
φ
/t≦
8.0, wherein σ
denotes the standard deviation of the particle diameter, φ
denotes the average particle diameter of the nonmagnetic powder comprised in the magnetic layer expressed in μ
m, and t denotes the thickness of the magnetic layer expressed in μ
m.
1 Assignment
0 Petitions
Accused Products
Abstract
An aspect of the present invention relates to a magnetic recording medium comprising a nonmagnetic layer containing a nonmagnetic powder and a binder and a magnetic layer containing a ferromagnetic powder and a binder in this order on a nonmagnetic support, wherein
- the magnetic layer comprises a nonmagnetic powder of which coefficient of variation CV of a particle size distribution as denoted by the following formula (1):
CV(%)=σ/φ×100 (1)
is less than 20 percent, and - the magnetic layer has a thickness being equal to or less than 0.1 μm and falling within a range of 1.1≦φ/t≦8.0, wherein σ denotes a standard deviation of a particle diameter, φ denotes an average particle diameter of the nonmagnetic powder comprised in the magnetic layer being expressed in μm, and t denotes a thickness of the magnetic layer being expressed in μm.
-
Citations
17 Claims
-
1. A magnetic recording medium comprising a nonmagnetic layer containing a nonmagnetic powder and a binder and a magnetic layer containing a ferromagnetic powder and a binder in this order on a nonmagnetic support, wherein
the magnetic layer comprises a nonmagnetic powder of which coefficient of variation CV of a particle size distribution as denoted by the following formula (1): -
CV(%)=σ
/φ
×
100
(1)is less than 20 percent, the nonmagnetic powder contained in the magnetic layer is silica powder, the magnetic layer further comprises an inorganic powder other than the silica powder, with a Mohs'"'"' hardness of equal to or higher than 6, the magnetic layer contains no carbon black, and the magnetic layer has a thickness being equal to or less than 0.1 μ
m and falling within a range of 1.1≦
φ
/t≦
8.0, wherein σ
denotes the standard deviation of the particle diameter, φ
denotes the average particle diameter of the nonmagnetic powder comprised in the magnetic layer expressed in μ
m, and t denotes the thickness of the magnetic layer expressed in μ
m. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
-
Specification