Claims
- 1. A magnetic recording medium comprising:
- a flexible substrate having opposed major surfaces,
- a ferromagnetic metal thin film layer on one surface of the substrate primarily comprising cobalt,
- an organic topcoat layer on the surface of the metal thin film layer, and
- a backboat layer on the surface of the substrate, the magnetic recording medium being used in combination with a magnetic head having a gap, characterized in that
- said organic topcoat layer contains a radiation-curable compound and an anti-oxidant,
- said backboat layer contains an inorganic pigment, an organic binder, and a lubricant,
- said metal thin film layer contains oxygen, and
- the medium has protrusions on its surface at an average density of at least 10.sup.5 /a.sup.2 per square millimeter of the surface, where a is the distance of the magnetic head gap as expressed in .mu.m and is from 0.1 to 0.4 .mu.m, said protrusions corresponding to the submicron particles of a size of 30 to 300 .ANG. within the medium, said protrusions having a height of 30 to 300 .ANG..
- 2. A magnetic recording medium according to claim 1 wherein said organic topcoat layer further contains a lubricant.
- 3. A magnetic recording medium according to claim 1 wherein said flexible substrate is comprised of a high polymer, and the protrusions conform to submicron particles having a size of 30 to 300 .ANG. which are placed on one surface of the substrate.
- 4. A magnetic recording medium according to claim 1 wherein said ferromagnetic metal thin film layer at the surface is covered with a ferromagnetic metal oxide coating.
- 5. A magnetic recording medium according to claim 1 wherein the organic binder in the backcoat layer is a radiation curable resin.
- 6. A magnetic recording medium according to claim 1 wherein the organic binder in the backcoat layer is a composition comprising
- (A) a plastic compound having at least two radiation-curable unsaturated double bonds and a molecular weight of 5,000 to 100,000,
- (B) a rubber-like compound having at least one radiation-curable unsaturated double bond or not being radiation curable and having a molecular weight of 3,000 to 100,000, and
- (C) a compound having at least one radiation-curable unsaturated double bond and a molecular weight of 200 to 3,000.
- 7. A magnetic recording medium according to claim 1 wherein the anti-oxidant in the organic topcoat layer is comprised of a radiation curable anti-oxidant.
- 8. A magnetic recording medium according to claim 2 wherein the lubricant in the organic topcoat is comprised of a radiation curable lubricant.
- 9. A magnetic recording medium according to claim 1 wherein said organic topcoat layer has a thickness of 10 to 100 .ANG..
- 10. A method for conducting recording/reproducing operation on a magnetic recording medium comprising a flexible substrate having opposed major surfaces, a ferromagnetic metal thin film layer on one surface of the substrate principally comprising cobalt, an organic topcoat layer on the surface of the metal thin film layer, and a backcoat layer on the other surface of the substrate, by passing the medium across a magnetic head having a gap, characterized in that
- said organic topcoat layer contains a radiation curable compound an anti-oxidant,
- said backcoat layer contains an inorganic pigment, an organic binder, and a lubricant,
- said metal thin film layer contains oxygen, and
- the medium has in average at least 10.sup.5 /a.sup.2 protrusions per square millimeter of the surface, where a is the distance of the magnetic head gas as expressed in .mu.m and being from 0.1 to 0.4 .mu.m, said protrusions corresponding to submicron particles of a size of 30 to 300 .ANG. within the medium, and said protrusions having a height of 30 to 300 .ANG..
- 11. A magnetic recording/reproducing method according to claim 10 wherein the organic topcoat layer further contains a lubricant.
- 12. A magnetic recording/reproducing method accord to claim 10 wherein at least an edge portion of the magnetic head including the gap is formed of a ferromagnetic metal material.
- 13. A magnetic recording/reproducing method according to claim 10 wherein the ferromagnetic metal material is a magnetic amorphous cobalt base alloy.
Priority Claims (1)
Number |
Date |
Country |
Kind |
59-164357 |
Jul 1984 |
JPX |
|
Parent Case Info
This is a continuation of Ser. No. 022,536 filed on Mar. 4, 1987, now abandoned which in turn is a continuation of Ser. No. 758,435 filed July 24, 1985 and now abandoned.
US Referenced Citations (6)
Continuations (2)
|
Number |
Date |
Country |
Parent |
22536 |
Mar 1987 |
|
Parent |
758435 |
Jul 1985 |
|