Magnetic recording medium

• US 20040018388A1
• Filed: 04/30/2003
• Published: 01/29/2004
• Est. Priority Date: 04/30/2002
• Status: Active Grant

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: Yamada, Hiroyuki, Kitamura, Kenichi
• Granted Patent: US 7,144,643 B2
• Time in Patent Office: Days
• US Class Current: 428/694B
• CPC Class Codes: G11B 5/70 on a base layer

Abstract

The invention provides a high performance magnetic recording medium used in the magnetic recording system using the MR head for the regeneration head, wherein the magnetic recording medium does not damage the MR head by direct sliding contact while having durability and self-cleaning power enough for preventing abrasion of the magnetic recording medium itself.

Claims

1. A magnetic recording medium used for a magnetic recording system having an MR head as a regeneration head, the recording medium comprising at least a nonmagnetic layer and magnetic layer sequentially laminated on one face of a nonmagnetic supporting member,

the magnetic recording medium being supported with a tension of 8.8×

10<sup>−

1</sup> N/cm per unit width between two guide rolls disposed with a center-to-center distance of 45 mm, and

an edge in the longitudinal direction of a rectangular column of a sendust bar having a square cross section pushing the magnetic layer forming face of the magnetic recording medium at the middle point between the guide rolls in the direction perpendicular to the running direction of the magnetic recording medium with a displacement of 2 mm,

wherein the width of the face at the edge of the sendust bar formed by abrasion of the sendust bar in the running direction of the recording medium is 9 to 25 μ

m after 200 times of reciprocating movement at a running speed of 2.5 m/s with a total running length of the magnetic recording medium of 250 m.

2. The magnetic recording medium according to claim 1, wherein the amount of fatty acids extracted in cyclohexane when the magnetic recording medium is immersed in cyclohexane for 2 minutes is 0.1 to 4.0 mg/m² of the surface area of the magnetic layer.