Magnetic recording medium
Provided is a magnetic recording medium affording both reduced head abrasion and good durability in high-density magnetic recording and reproduction systems employing MR heads as reproduction heads. The magnetic recording medium comprises a nonmagnetic layer comprising a nonmagnetic powder and a binder and a magnetic layer comprising a ferromagnetic powder, a binder and an abrasive in this order on a nonmagnetic support. The abrasive comprises carbide having a mean particle diameter ranging from 0.02 to 0.10 micrometer.
1 . A magnetic recording medium comprising a nonmagnetic layer comprising a nonmagnetic powder and a binder and a magnetic layer comprising a ferromagnetic powder, a binder and an abrasive in this order on a nonmagnetic support, wherein
said abrasive comprises carbide having a mean particle diameter ranging from 0.02 to 0.10 micrometer.
2 . The magnetic recording medium according to claim 1 , wherein said magnetic layer comprises said carbide in an amount of 0.5 to 15 weight parts per 100 parts of the ferromagnetic powder.
3 . The magnetic recording medium according to claim 1 , wherein Sendust abrasion width Ws of said magnetic layer ranges from 20 to 60 micrometers and a ratio (Ws/Wa) of Sendust abrasion width Ws to AlTiC abrasion width Wa of said magnetic layer is equal to or higher than 10.
4 . The magnetic recording medium according to claim 3 , wherein the ratio (Ws/Wa) of Sendust abrasion width Ws to AlTiC abrasion width Wa of said magnetic layer ranges from 10 to 100.
5 . The magnetic recording medium according to claim 3 , wherein the ratio (Ws/Wa) of Sendust abrasion width Ws to AlTiC abrasion width Wa of said magnetic layer ranges from 10 to 60.
6 . The magnetic recording medium according to claim 3 , wherein the Sendust abrasion width Ws of said magnetic layer ranges from 20 to 50 micrometers.
7 . The magnetic recording medium according to claim 1 , wherein said carbide has a Mohs' hardness of equal to or higher than 8 but less than 10.
8 . The magnetic recording medium according to claim 1 , wherein said carbide has a Mohs' hardness of equal to or higher than 9 but less than 10.
9 . The magnetic recording medium according to claim 1 , wherein said carbide is at least one selected from the group consisting of TiC, SiC, ZrC, B 4 C, WC and VC.
10 . The magnetic recording medium according to claim 1 , wherein said carbide is at least one selected from the group consisting of TiC, SiC and B 4 C
11 . The magnetic recording medium according to claim 1 , wherein said magnetic layer has a thickness ranging from 0.03 to 0.10 micrometer.
12 . The magnetic recording medium according to claim 1 , wherein said ferromagnetic layer is a ferromagnetic metal powder having a mean major axis length ranging from 30 to 50 nm or a hexagonal ferrite powder having a mean plate diameter ranging from 10 to 40 nm.
13 . A method of recording a magnetic signal on the magnetic recording medium according to claim 1 with a recording head and reproducing the magnetic signal with a magnetoresistive head.
14 . An apparatus comprising a recording head, a magnetoresistive reproduction head and the magnetic recording medium according to claim 1.