Magnetic recording medium

• US 4,746,559 A
• Filed: 11/18/1986
• Issued: 05/24/1988
• Est. Priority Date: 11/18/1985
• Status: Expired due to Term

• Current Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Nishikawa, Yasuo, Ishikuro, Tadashi
• Primary Examiner(s): Robinson, Ellis P.
• Application Number:
  US06/931,828
• Time in Patent Office: 553 Days
• Field of Search: 428/694, 428/695, 428/457, 428/216, 428/142, 428/336, 428/335, 428/148, 428/900, 427/131, 427/132, 427/128, 360/134-136
• US Class Current: 428/142
• CPC Class Codes: G11B 5/72 Protective coatings, e.g. anti-static or antifriction
• CPC Class Codes: Y10S 428/90 Magnetic feature
• CPC Class Codes: Y10T 428/24273 including aperture
• CPC Class Codes: Y10T 428/24281 Struck out portion type
• CPC Class Codes: Y10T 428/24364 with transparent or protective coating
• CPC Class Codes: Y10T 428/24413 Metal or metal compound
• CPC Class Codes: Y10T 428/24975 No layer or component greater than 5 mils thick
• CPC Class Codes: Y10T 428/264 Up to 3 mils
• CPC Class Codes: Y10T 428/265 1 mil or less
• CPC Class Codes: Y10T 428/31678 Of metal

Abstract

Disclosed is a magnetic recording medium comprising a non-magnetic support having provided thereon a ferromagnetic metal thin film provided with a layer containing a compound having a mercapto group. This layer may also contain an ester bond. The magnetic recording medium shows improved running properties and wear resistance over wide ranges of temperature and humidity.

Claims

1. A magnetic recording medium comprising a non-magnetic support having provided thereon a ferromagnetic metal thin film provided with a layer containing a compound having a mercapto group which has a molecular weight of from about 78 to about 10,000, wherein:

said compound having a mercapto group also has an ester bond;

the layer containing the compound having a mercapto group has a thickness of 0.5 mg/m² to 100 mg/m² and wherein said compound having a mercapto group and an ester bond is represented by general formula

space="preserve" listing-type="equation">A--COO--B

wherein one of A and B represents a hydrocarbon group substituted with one or more mercapto groups, and the other represents a hydrocarbon group, or both of A and B independently represent a hydrocarbon group substituted with one or more mercapto group.

2. A magnetic recording medium as claimed in claim 1, wherein said support has provided thereon an under layer.

3. A magnetic recording medium as claimed in claim 1, wherein said support has provided thereon an under layer.

4. A magnetic recording medium as claimed in claim 1, wherein said metal thin film is one treated with a surface active agent or a coupling agent.

5. A magnetic recording medium as claimed in claim 1, wherein said metal thin film is one treated with a surface active agent or a coupling agent.

6. A magnetic recording medium as claimed in claim 1, wherein said hydrocarbon group substituted with one or more mercapto groups contains at least 3 carbon atoms.

7. A magnetic recording medium as claimed in claim 1, wherein said compound having a mercapto group and an ester bond is represented by general formula

8. A magnetic recording medium as claimed in claim 7, wherein said compound having a mercapto group and an ester bond is selected from the group consisting of monoester or diester compounds and oligoester or polyester compounds having a mercapto group.

9. A magnetic recording medium as claimed in claim 7, wherein said compound having a mercapto group and ester bond is selected from the group consisting of behenyl β

-mercaptopropionate, octadecyl β

-mercaptopropionate, dodecyl β

-mercaptopropionate, octyl β

-mercaptopropionate, oleyl β

-mercaptopropionate, behenyl thioglycolate, octadecyl thioglycolate, dodecyl thioglycolate, octyl thioglycolate, oleyl thioglycolate, behenyl thiosalycilate, octadecyl thiosalycilate, dodecyl thiosalycilate, octyl thiosalycilate, methyl thiosalycilate, oleyl thiosalcilate, 2-mercaptoethyl stearate, 2-mercaptoethyl oleate, 2-mercaptoethyl myristate, and 2-mercaptoethyl laurate.

10. A magnetic recording medium as claimed in claim 7, wherein said compound having a mercapto group and an ester bond is selected from the group consisting of behenyl β

-mercaptopriopionate, octadecyl β

-mercaptopropionate, dodecyl β

-mercaptopropionate, oleyl-mercaptopropionate, behenyl thioglycolate, octadecyl thioglycolate, dodecyl thioglycolate, oleyl thioglycolate, 2-mercaptoethyl stearate, 2-mercaptoethyl oleate and 2-mercaptoethyl myristate.

11. A magnetic recording medium as claimed in claim 1, wherein said compound having a mercapto group and an ester bond is a product derived from one or more of a polyfunctional acid, a polyfunctional alcohol, an acid having a hydroxy group and a self-condensation product of an acid having a hydroxy group.

12. A magnetic recording medium as claimed in claim 1, wherein said layer containing a compound having a mercapto group has a surface unevenness of 10 to 1,000 Angstroms.

13. A magnetic recording medium as claimed in claim 1, wherein said layer containing a compound having a mercapto group has a surface unevenness of 10 to 1,000 Angstrom.

14. A magnetic recording medium as claimed in claim 1, wherein the thickness of the support is from about 4 to about 50 μ

m.

15. A magnetic recording medium as claimed in claim 1, wherein the thickness of the support is from about 4 to about 50 μ

m.