Claims
- 1. A magnetic recording medium comprising a nonmagnetic substrate having two surfaces, a back-coat layer formed in a vacuum from a metal, a semi-metal or an oxide thereof on a surface of said nonmagnetic substrate and a magnetic layer formed on the other surface of said nonmagnetic substrate than said back coat layer-deposited surface.
- 2. A magnetic recording medium comprising a nonmagnetic substrate having two surfaces, a back-coat layer formed in a vacuum from a metal, a semi-metal or an oxide thereof on a surface of a nonmagnetic substrate, a magnetic layer formed on the other surface of said nonmagnetic substrate than said back coat layer-deposited surface, and a top coat layer formed in vacuum on said magnetic layer by spraying a lubricant.
- 3. A magnetic recording medium, comprising a nonmagnetic substrate having two surfaces, a magnetic layer formed on a surface of said non-magnetic substrate and a top-coat layer formed in a vacuum on said magnetic layer by spraying a lubricant.
- 4. A magnetic recording medium, comprising a nonmagnetic substrate having two surfaces, a back-coat layer of carbon black formed in a vacuum on a surface of said nonmagnetic substrate, and a magnetic layer formed on said other surface of said nonmagnetic substrate.
- 5. The magnetic recording medium according to claims 1, 2 or 4 wherein the thickness of said backcoat layer ranges from 0.2 to 1.0 .mu.m.
- 6. The magnetic recording medium according to claims 1 or 2, wherein said metal is selected from the group consisting of Al, Cu, Zn, Sn, Ni, and Ag, or alloys thereof.
- 7. The magnetic recording medium according to claims 1 or 2, wherein said semi-metal is selected from the group consisting of Si, Ge, As, Sc and Sb.
- 8. The magnetic recording medium according to claims 1 or 2, wherein the surface resistance of said metal backcoat layer is 5 to 10.sup.5 .OMEGA..
- 9. The magnetic recording medium according to claims 1 or 2, wherein the surface resistance of said semi-metal layer is 10.sup.5 to 10.sup.8 .OMEGA..
- 10. The magnetic recording medium according to claims 2 or 3, wherein said lubricant is a fluorine-containing lubricant.
- 11. The magnetic recording medium according to claims 2 or 3, wherein said lubricant is a perfluoropolyether having a molecular weight of 2,000 to 5,000.
- 12. The magnetic recording medium according to claims 2 or 3, wherein the thickness of said topcoat is in the range of 50 to 200 .ANG..
- 13. The magnetic recording medium according claims 1 or 2, wherein said metal is Al or Cu or alloys thereof.
- 14. The material according to claims 1 or 2, wherein said semi-metal is Si.
Priority Claims (2)
Number |
Date |
Country |
Kind |
4-247922 |
Sep 1992 |
JPX |
|
5-181501 |
Jul 1993 |
JPX |
|
Parent Case Info
This application is a divisional of application Ser. No. 08/122,286, filed on Sep. 17. 1993, now U.S. Pat. No. 5,593,723, the entire contents of which are hereby incorporated by reference.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
4824724 |
Ueda et al. |
Apr 1989 |
|
5593723 |
Kitaori |
Jan 1997 |
|
Foreign Referenced Citations (5)
Number |
Date |
Country |
0440259 |
Aug 1991 |
EPX |
60-069821 |
Aug 1985 |
JPX |
60-191435 |
Sep 1985 |
JPX |
61-126633 |
Oct 1986 |
JPX |
8905362 |
Jun 1989 |
WOX |
Non-Patent Literature Citations (4)
Entry |
Abstract of Japan, vol. 10, No. 45 (p. 430), 21 Feb. 1986 & JP-A-60 191 435 (Hitachi Maxell). |
Abstract o Japan, vol. 7, No. 57 (p. 510), 28 Oct. 1986 & JP-A-61 126 633 (Matsushita Electric). |
Abstract of Japan, vol. 9, No. 207 (p. 382), 24 Aug. 1985 & JP-A-60 069 821 (Hitachi Condenser). |
Abstract of Japan, vol. 7, No. 57 (p. 181), 9 Mar. 1983 & JP-A-57 203 230 (Hitachi Maxell). |
Divisions (1)
|
Number |
Date |
Country |
Parent |
122286 |
Sep 1993 |
|