MAGNETIC TAPE AND METHOD OF MANUFACTURING THE SAME

• US 20160093323A1
• Filed: 09/30/2015
• Published: 03/31/2016
• Est. Priority Date: 09/30/2014
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: OMURA, Kazufumi
• Granted Patent: US 9,959,894 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G11B 5/71 characterised by the lubricant
• CPC Class Codes: G11B 5/733 characterised by the addition of non-magnetic particles base layers having a non-magnetic layer under a soft magnetic layer G11B5/736; magnetic recording media substrates G11B5/739
• CPC Class Codes: G11B 5/78 Tape carriers

Abstract

The magnetic tape comprises a nonmagnetic layer comprising nonmagnetic powder and binder on a nonmagnetic support, and comprises a magnetic layer comprising ferromagnetic powder and binder on the nonmagnetic layer, wherein a fatty acid ester, a fatty acid amide, and a fatty acid are contained in either one or both of the magnetic layer and the nonmagnetic layer, with the magnetic layer and nonmagnetic layer each comprising at least one selected from the group consisting of a fatty acid ester, a fatty acid amide, and a fatty acid, a quantity of fatty acid ester per unit area of the magnetic layer in extraction components extracted from a surface of the magnetic layer with n-hexane falls within a range of 1.00 mg/m² to 10.00 mg/m², and a weight ratio of the quantity of fatty acid ester per unit area of the magnetic layer to a combined total of a quantity of fatty acid amide and a quantity of fatty acid, quantity of fatty acid ester/(quantity of fatty acid amide+quantity of fatty acid), per unit area of the magnetic layer falls within a range of 1.00 to 3.00 in the extraction components.

Claims

1. A magnetic tape,

which comprises a nonmagnetic layer comprising nonmagnetic powder and binder on a nonmagnetic support, and comprises a magnetic layer comprising ferromagnetic powder and binder on the nonmagnetic layer;

wherein a fatty acid ester, a fatty acid amide, and a fatty acid are contained in either one or both of the magnetic layer and the nonmagnetic layer, with the magnetic layer and nonmagnetic layer each comprising at least one selected from the group consisting of a fatty acid ester, a fatty acid amide, and a fatty acid;

a quantity of fatty acid ester per unit area of the magnetic layer in extraction components extracted from a surface of the magnetic layer with n-hexane falls within a range of 1.00 mg/m² to 10.00 mg/m²; and

a weight ratio of the quantity of fatty acid ester per unit area of the magnetic layer to a combined total of a quantity of fatty acid amide and a quantity of fatty acid, quantity of fatty acid ester/(quantity of fatty acid amide+quantity of fatty acid), per unit area of the magnetic layer falls within a range of 1.00 to 3.00 in the extraction components.

2. The magnetic tape according to claim 1, wherein both the magnetic layer and the nonmagnetic layer comprise a fatty acid ester, fatty acid amide, and fatty acid.

3. The magnetic tape according to claim 1, wherein a weight ratio of the quantity of fatty acid ester per unit area of the magnetic layer to the quantity of fatty acid amide per unit area of the magnetic layer in the extraction components, quantity of fatty acid ester/quantity of fatty acid amide falls within a range of 5.00 to 20.00.

4. The magnetic tape according to claim 1, wherein a weight ratio of the quantity of fatty acid ester per unit area of the magnetic layer to the quantity of fatty acid per unit area of the magnetic layer in the extraction components, quantity of fatty acid ester/quantity of fatty acid, falls within a range of 1.00 to 6.00.

5. The magnetic tape according to claim 1, wherein, in the extraction components,

a weight ratio of the quantity of fatty acid ester per unit area of the magnetic layer to the quantity of fatty acid amide per unit area of the magnetic layer, quantity of fatty acid ester/quantity of fatty acid amide, falls within a range of 5.00 to 20.00, and

a weight ratio of the quantity of fatty acid ester per unit area of the magnetic layer to the quantity of fatty acid per unit area of the magnetic layer, quantity of fatty acid ester/quantity of fatty acid, falls within a range of 1.00 to 6.00.

6. The magnetic tape according to claim 1, wherein the nonmagnetic powder of the nonmagnetic layer comprises at least carbon black.

7. The magnetic tape according to claim 1, wherein the nonmagnetic powder of the nonmagnetic layer comprises 10.00 to 100.00 weight parts of carbon black per a total quantity of 100.00 weight parts of nonmagnetic powder.

8. The magnetic tape according to claim 1, wherein a thickness of the nonmagnetic layer falls within a range of 0.03 μ

m to 0.20 μ

m.

9. The magnetic tape according to claim 1, which is a magnetic tape that has been formed by coating and drying a coating composition for forming a nonmagnetic layer on a nonmagnetic support to form a nonmagnetic layer, and then coating and drying a coating composition for forming the magnetic layer over the nonmagnetic layer.

10. A method of manufacturing a magnetic tape, wherein

the magnetic tape to be manufactured is a magnetic tape which comprises a nonmagnetic layer comprising nonmagnetic powder and binder on a nonmagnetic support, and comprises a magnetic layer comprising ferromagnetic powder and binder on the nonmagnetic layer;

wherein a fatty acid ester, a fatty acid amide, and a fatty acid are contained in either one or both of the magnetic layer and the nonmagnetic layer, with the magnetic layer and nonmagnetic layer each comprising at least one selected from the group consisting of a fatty acid ester, a fatty acid amide, and a fatty acid;

a quantity of fatty acid ester per unit area of the magnetic layer in extraction components extracted from a surface of the magnetic layer with n-hexane falls within a range of 1.00 mg/m² to 10.00 mg/m²; and

a weight ratio of the quantity of fatty acid ester per unit area of the magnetic layer to a combined total of a quantity of fatty acid amide and a quantity of fatty acid, quantity of fatty acid ester/(quantity of fatty acid amide+quantity of fatty acid), per unit area of the magnetic layer falls within a range of 1.00 to 3.00 in the extraction components; and

wherein

the method comprises;

coating and drying a coating composition for forming the nonmagnetic layer on the nonmagnetic support to form the nonmagnetic layer; and

coating and drying a coating composition for forming the magnetic layer on the nonmagnetic layer that has been formed to form the magnetic layer.

11. The method of manufacturing a magnetic tape according to claim 10, wherein, in the magnetic tape, both the magnetic layer and the nonmagnetic layer comprise a fatty acid ester, fatty acid amide, and fatty acid.

12. The method of manufacturing a magnetic tape according to claim 10, wherein, in the magnetic tape, a weight ratio of the quantity of fatty acid ester per unit area of the magnetic layer to the quantity of fatty acid amide per unit area of the magnetic layer in the extraction components, quantity of fatty acid ester/quantity of fatty acid amide falls within a range of 5.00 to 20.00.

13. The method of manufacturing a magnetic tape according to claim 10, wherein, in the magnetic tape, a weight ratio of the quantity of fatty acid ester per unit area of the magnetic layer to the quantity of fatty acid per unit area of the magnetic layer in the extraction components, quantity of fatty acid ester/quantity of fatty acid, falls within a range of 1.00 to 6.00.

14. The method of manufacturing a magnetic tape according to claim 10, wherein, in the extraction components of the magnetic tape,

a weight ratio of the quantity of fatty acid ester per unit area of the magnetic layer to the quantity of fatty acid amide per unit area of the magnetic layer, quantity of fatty acid ester/quantity of fatty acid amide, falls within a range of 5.00 to 20.00, and

a weight ratio of the quantity of fatty acid ester per unit area of the magnetic layer to the quantity of fatty acid per unit area of the magnetic layer, quantity of fatty acid ester/quantity of fatty acid, falls within a range of 1.00 to 6.00.

15. The method of manufacturing a magnetic tape according to claim 10, wherein, in the magnetic tape, the nonmagnetic powder of the nonmagnetic layer comprises at least carbon black.

16. The method of manufacturing a magnetic tape according to claim 10, wherein, in the magnetic tape, the nonmagnetic powder of the nonmagnetic layer comprises 10.00 to 100.00 weight parts of carbon black per a total quantity of 100.00 weight parts of nonmagnetic powder.

17. The method of manufacturing a magnetic tape according to claim 10, wherein, in the magnetic tape, a thickness of the nonmagnetic layer falls within a range of 0.03 μ

m to 0.20 μ

m.