MAGNETIC TAPE

• US 20180240495A1
• Filed: 02/20/2018
• Published: 08/23/2018
• Est. Priority Date: 02/20/2017
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: KASADA, Norihito
• Granted Patent: US 10,482,913 B2
• Time in Patent Office: Days
• CPC Class Codes: G11B 5/00813 magnetic tapes
• CPC Class Codes: G11B 5/70 on a base layer
• CPC Class Codes: G11B 5/70615 containing Fe metal or alloys G11B5/70621 takes precedence
• CPC Class Codes: G11B 5/70678 Ferrites
• CPC Class Codes: G11B 5/7085 non-magnetic abrasive particles
• CPC Class Codes: G11B 5/712 characterised by the surface treatment or coating of magnetic particles
• CPC Class Codes: G11B 5/78 Tape carriers

Abstract

The magnetic tape includes a non-magnetic support; a non-magnetic layer including non-magnetic powder and a binding agent on the non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic layer, in which the total thickness of the non-magnetic layer and the magnetic layer is equal to or smaller than 0.60 μm, the magnetic layer includes an abrasive, a percentage of a plan view maximum area of the abrasive confirmed in a region having a size of 4.3 μm×6.3 μm of the surface of the magnetic layer with respect to the total area of the region, obtained by plane observation performed by using a scanning electron microscope is equal to or greater than 0.02% and less than 0.06%, and a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer is equal to or smaller than 0.050.

Claims

1. A magnetic tape comprising:

a non-magnetic support;

a non-magnetic layer including non-magnetic powder and a binding agent on the non-magnetic support; and

a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic layer,

wherein the total thickness of the non-magnetic layer and the magnetic layer is equal to or smaller than 0.60 μ

m,

the magnetic layer includes an abrasive,

a percentage of a plan view maximum area of the abrasive confirmed in a region having a size of 4.3 μ

m×

6.3 μ

m of the surface of the magnetic layer with respect to the total area of the region, obtained by plane observation performed by using a scanning electron microscope is equal to or greater than 0.02% and less than 0.06%, and

a logarithmic decrement acquired by a pendulum viscoelasticity test performed regarding the surface of the magnetic layer is equal to or smaller than 0.050.

2. The magnetic tape according to claim 1,

wherein the logarithmic decrement is 0.010 to 0.050.

3. The magnetic tape according to claim 1,

wherein the percentage of a plan view maximum area of the abrasive confirmed in a region having a size of 4.3 μ

m×

6.3 μ

m of the surface of the magnetic layer with respect to the total area of the region, obtained by plane observation performed by using a scanning electron microscope is 0.02% to 0.05%.

4. The magnetic tape according to claim 2,

wherein the percentage of a plan view maximum area of the abrasive confirmed in a region having a size of 4.3 μ

m×

6.3 μ

m of the surface of the magnetic layer with respect to the total area of the region, obtained by plane observation performed by using a scanning electron microscope is 0.02% to 0.05%.

5. The magnetic tape according to claim 1,

wherein the total thickness of the non-magnetic layer and the magnetic layer is 0.20 μ

m to 0.60 μ

m.

6. The magnetic tape according to claim 1,

wherein the BET specific surface area of the abrasive is 14 to 40 m²/g.

7. The magnetic tape according to claim 1,

wherein the abrasive is alumina powder.

8. The magnetic tape according to claim 1,

wherein the magnetic layer includes an aromatic hydrocarbon compound including a phenolic hydroxyl group.

9. The magnetic tape according to claim 1,

wherein the ferromagnetic powder is ferromagnetic hexagonal ferrite powder.

10. The magnetic tape according to claim 9,

wherein the ferromagnetic hexagonal ferrite powder includes Al.