Information
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Patent Application
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20070231606
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Publication Number
20070231606
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Date Filed
April 02, 200717 years ago
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Date Published
October 04, 200716 years ago
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Inventors
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Original Assignees
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CPC
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US Classifications
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International Classifications
Abstract
A magnetic recording medium comprising a substrate and a magnetic layer containing ferromagnetic metal powder and a binder, wherein the ferromagnetic metal powder contains iron, cobalt and form 2 to 20 atom % of yttrium based on a total of iron and cobalt contained in the ferromagnetic metal powder and has an average length of 50 nm or smaller, and the magnetic recording medium has a test value of at least 100 passes in a magnetoresistive head resistance reduction test performed as defined herein.
Claims
- 1. A magnetic recording medium comprising a substrate and a magnetic layer containing ferromagnetic metal powder and a binder,
wherein the ferromagnetic metal powder contains iron, cobalt and from 2 to 20 atom % of yttrium based on a total of iron and cobalt contained in the ferromagnetic metal powder and has an average length of 50 nm or smaller, andthe magnetic recording medium has a test value of at least 100 passes in a magnetoresistive head resistance reduction test performed as follows:A 600 m long magnetic recording medium of tape form is recorded and repeatedly reproduced while being shuttled on a drive equipped with an MR head in a 13° C., 15% RH environment until the resistance of the MR head reduces by 40 Ω, and a number of passes of the tape at that time is a test value.
- 2. The magnetic recording medium according to claim 1, wherein the magnetic layer has a thickness of 100 nm or smaller.
- 3. The magnetic recording medium according to claim 1, wherein the ferromagnetic metal powder has an average breadth of 15 nm or smaller.
- 4. The magnetic recording medium according to claim 1, further comprising a nonmagnetic layer containing nonmagnetic powder and a binder between the substrate and the magnetic layer.
- 5. The magnetic recording medium according to claim 1, wherein a fragment intensity of fatty acid metal salt on a surface of the magnetic layer detected by use of a time-of-flight secondary ion mass spectrometer is 1% or less based on a total fragment intensity of iron and cobalt on the surface of the magnetic layer.
- 6. The magnetic recording medium according to claim 1, wherein a fragment intensity of fatty acid metal salt on a surface of the magnetic layer detected by use of a time-of-flight secondary ion mass spectrometer is 0.7% or less based on a total fragment intensity of iron and cobalt on the surface of the magnetic layer.
- 7. A process for producing the magnetic recording medium according to claim 1, comprising: detecting fragment ions of an organic compound on a surface of the magnetic layer by use of a time-of-flight secondary ion mass spectrometer.
- 8. The process according to claim 7, wherein the organic compound is a fatty acid metal salt.
- 9. The process according to claim 8, wherein a fragment intensity of the fatty acid metal salt is 1% or less based on a total fragment intensity of iron and cobalt.
- 10. The process according to claim 9, wherein the fatty acid metal salt is a yttrium salt, and a fragment intensity of the yttrium salt is 1% or less based on the total fragment intensity of iron and cobalt.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2006-099934 |
Mar 2006 |
JP |
national |