Magnetic tape

• US 20060068232A1
• Filed: 09/24/2004
• Published: 03/30/2006
• Est. Priority Date: 09/24/2004
• Status: Abandoned Application

• Current Assignee: Hitachi Maxell Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi Maxell Limited (Hitachi, Ltd.)
• Inventors: Kuse, Sadamu, Kawarai, Seigi, Mikamo, Hisanobu
• Application Number:
  US10/948,259
• Publication Number:
  US 20060068232A1
• Time in Patent Office: Days
• US Class Current: 428/842.900
• CPC Class Codes: G11B 5/70626 containing non-metallic substances
• CPC Class Codes: G11B 5/714 characterised by the dimension of the magnetic particles
• CPC Class Codes: G11B 5/716 characterised by two or more magnetic layers

Abstract

A magnetic tape comprising a non-magnetic substrate and at least one magnetic layer formed on one surface of the non-magnetic substrate, characterized in that magnetic particles contained in an uppermost magnetic layer of the magnetic layer are substantially granular particles with a particle size of 30 nm or less, and that the ratio of a coercive force Hc_M in the machine direction to a coercive force Hc_T in the transverse direction, i.e., [Hc_M/Hc_T], is at least 2.2. This magnetic tape has a capacity capable of corresponding to mass storage of 1 TB or more, and achieves a high ratio of reproducing output to noises (C/N), particularly for signals within a short wavelength range, thus showing excellent high-density recording performance.

Claims

1. A magnetic tape comprising a non-magnetic substrate and at least one magnetic layer formed on one surface of the non-magnetic substrate, wherein magnetic particles contained in an uppermost magnetic layer of said magnetic layer are substantially granular particles with a particle size of 30 nm or less, and the ratio of a coercive force Hc_M in the machine direction to a coercive force Hc_T in the transverse direction, [Hc_M/Hc_T], is at least 2.2.

2. The magnetic tape according to claim 1, wherein an axial ratio of the magnetic particles contained in said uppermost magnetic layer is less than 2.

3. The magnetic tape according to claim 1, wherein the magnetic particles contained in said uppermost magnetic layer are iron nitride-based magnetic particles.

4. The magnetic tape according to claim 1, wherein the particle size of the magnetic particles contained in said uppermost magnetic layer is 20 nm or less.