IP Library Granted Patent US 7,494,728
Granted Patent B2
US 7,494,728 · App. 10/383,768 · Granted Feb 24, 2009

Magnetic tape and magnetic tape cartridge

Assignee: Hitachi Maxell, Ltd.
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Quick Facts
Patent No.
US 7,494,728
App. No.
10/383,768
Granted
Feb 24, 2009
Kind
B2
Abstract

A magnetic tape comprising a non-magnetic support, a magnetic layer containing magnetic powder which is formed on one side of the non-magnetic support, a primer layer containing non-magnetic powder which is formed between the non-magnetic support and the magnetic layer, and a backcoat layer containing non-magnetic powder which is formed on the other side of the non-magnetic support, wherein the magnetic layer contains the magnetic powder which comprises plate, granular or ellipsoidal magnetic particles with a particle diameter of 5 to 50 nm, and has a thickness of 0.09 μm or less, and wherein at least one of the primer layer and the backcoat layer contains non-magnetic plate particles with a particle diameter of 10 to 100 nm.

Claims (13)

1. A magnetic tape comprising a non-magnetic support, a magnetic layer containing a magnetic powder which is formed on one side of the non-magnetic support, wherein said magnetic powder comprises plate or granular magnetic particles with a particle diameter of 5 to 50 nm, and a thickness of said magnetic layer is 0.01 μm to 0.05 μm, a primer layer containing non-magnetic powder which is formed between the non-magnetic support and the magnetic layer, and a backcoat layer containing non-magnetic powder which is formed on the other side of the non-magnetic support, wherein the coefficient of temperature expansion in the tape widthwise direction is (0 to 8) ×10 −6 /° C., and the coefficient of humidity expansion in the tape widthwise direction is (0 to 10) ×10 −6 /%RH; wherein the amount of edge weave present on either edge of the magnetic tape as the reference side for the running of the tape is less than 0.8 μm; and wherein a rate of fluctuation in reproducing output in at least one of a tape lengthwise direction and a tape widthwise direction is 10% or less.

2. The magnetic tape according to claim 1 , wherein at least one of the primer layer and the backcoat layer contains non-magnetic plate particles with a particle diameter of 10 to 100 nm.

3. The magnetic tape according to claim 1 , wherein at least one of said primer layer and said backcoat layer contains non-magnetic plate particles.

4. The magnetic tape according to claim 1 , wherein said primer layer contains carbon black having a particle diameter of 0.01 to 0.1 μm and aluminum oxide having a particle diameter of 0.1 to 0.5 μm.

5. The magnetic tape according to claim 1 , wherein said rate of fluctuation in reproducing output is at least 5.1%.

6. A magnetic tape comprising a non-magnetic support, a magnetic layer containing magnetic powder which is formed on one side of the non-magnetic support, wherein said magnetic powder comprises plate or granular magnetic particles with a particle diameter of 5 to 50 nm, and a thickness of said magnetic layer is 0.05 μm to 0.09 μm, a primer layer containing non-magnetic powder which is formed between the non-magnetic support and the magnetic layer, and a backcoat layer containing non-magnetic powder which is formed on the other side of the non-magnetic support, wherein the coefficient of temperature expansion in the tape widthwise direction is (0 to 8)×10 −6 /° C., and the coefficient of humidity expansion in the tape widthwise direction is (0 to 10)×10 −6 /%RH; wherein the amount of edge weave present on either edge of the magnetic tape as the reference side for the running of the tape is less than 0.8 μm; and wherein a rate of fluctuation in reproducing output in at least one of a tape lengthwise direction and a tape widthwise direction is 8% or less.

7. The magnetic tape according to claim 6 , wherein said rate of fluctuation in reproducing output is at least 5.1%.

8. The magnetic tape according to claim 6 , wherein at least one of said primer layer and said backcoat layer contains non-magnetic plate particles.

9. The magnetic tape according to claim 8 , wherein said non-magnetic plate particles have a particle diameter of 10 to 100 nm.

10. The magnetic layer according to claim 6 , wherein said primer layer contains carbon black having a particle diameter of 0.01 to 0.1 μm and aluminum oxide having a particle diameter of 0.1 to 0.5 μm.

11. The magnetic tape according to claim 7 , wherein at least one of said primer layer and said backcoat layer contains non-magnetic plate particles.

12. The magnetic tape according to claim 11 , wherein said non-magnetic plate particles have a particle diameter of 10 to 100 nm.

13. The magnetic layer according to claim 7 , wherein said primer layer contains carbon black having a particle diameter of 0.01 to 0.1 μm and aluminum oxide having a particle diameter of 0.1 to 0.5 μm.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 29, 2017
From: HITACHI MAXELL, LTD.
To: FUJIFILM CORPORATION
Reel/Frame 044053/0281 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 7, 2003
From: KUSE, SADAMU; DOI, TSUGIHIRO; INOUE, TETSUTARO; KISHIMOTO, MIKIO
To: HITACHI MAXELL, LTD.
Reel/Frame 014243/0925 →
Priority Claims (1)
JP P2002-125029 · Apr 25, 2002 · national
Continuity (1)
Related Publication 20040110037A1 · Jun 10, 2004