Magnetic recording medium

• US 20040197605A1
• Filed: 03/23/2004
• Published: 10/07/2004
• Est. Priority Date: 03/31/2003
• Status: Active Grant

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: Seki, Akihiko, Kuwajima, Takayoshi, Yajima, Naoto
• Granted Patent: US 7,011,900 B2
• Time in Patent Office: Days
• US Class Current: 428/842
• CPC Class Codes: G11B 5/00813 magnetic tapes
• CPC Class Codes: G11B 5/70 on a base layer
• CPC Class Codes: G11B 5/735 characterised by the back layer magnetic recording media substrates G11B5/739
• CPC Class Codes: G11B 5/78 Tape carriers
• CPC Class Codes: Y10T 428/12465 having magnetic properties, or preformed fiber orientation coordinate with shape
• CPC Class Codes: Y10T 428/12993 Surface feature [e.g., rough, mirror]

Abstract

The present invention provides a magnetic recording medium, in particular a linear recording tape for use with computers, comprising a back coat layer with proper strength and having excellent electromagnetic conversion characteristics and excellent running durability. The magnetic recording medium comprises a lower non-magnetic layer on one surface of a non-magnetic support, an upper magnetic layer on the lower non-magnetic layer, and the back coat layer on the other surface of the non-magnetic support. And the magnetic layer has a SENDUST abrasion volume S_MC of 3.0×10⁴(μm)³/m or less and a ratio (S_BC/S_MC) of a SENDUST abrasion volume S_BC by the back coat layer to the SENDUST abrasion volume S_MC by the magnetic layer is in the range of 0.5 to 3.0.

Claims

1. A magnetic recording medium, comprising a lower non-magnetic layer on one surface of a non-magnetic support, an upper magnetic layer on the lower non-magnetic layer, and a back coat layer on the other surface of the non-magnetic support, wherein the magnetic layer has a SENDUST abrasion volume S_MC of 3.0×

10⁴(μ

m)³/m or less and a ratio (S_BC/S_MC) of a SENDUST abrasion volume S_BC by the back coat layer to the SENDUST abrasion volume S_MC by the magnetic layer is in the range of 0.5 to 3.0.

2. The magnetic recording medium according to claim 1, wherein the SENDUST abrasion volume S_BC by the back coat layer is in the range of 0.4×

10⁴ (μ

m)³/m or more and 4.0×

10⁴(μ

m)³/m or less.

3. The magnetic recording medium according to claim 1, wherein a surface roughness Ra of the back coat layer is 20 nm or less.

4. The magnetic recording medium according to claim 1, wherein an AFM surface roughness Ra of the magnetic layer is in the range of 3.0 to 8.0 nm.

5. The magnetic recording medium according to claim 1, wherein the magnetic layer has a thickness of 0.3 μ

m or less.

6. The magnetic recording medium according to claim 1, wherein a coefficient of kinetic friction of the back coat layer is in the range of 0.10 to 0.40.

7. The magnetic recording medium according to claim 1, wherein a centerline average roughness Ra of the surface of the magnetic layer is in the range of 1.0 to 8.0 nm.