Magnetic recording medium and method of producing the same

• US 6,316,062 B1
• Filed: 03/17/2000
• Issued: 11/13/2001
• Est. Priority Date: 09/17/1997
• Status: Expired due to Term

• Current Assignee: Showa Denko KK
• Original Assignee: Showa Denko KK
• Inventors: Yoneyama, Kenichi, Kobayashi, Kazuo, Sakai, Hiroshi, Sakaguchi, Ryuji, Suzuki, Mikio, Ohnami, Kazunori
• Primary Examiner(s): PIANALTO, BERNARD D
• Application Number:
  US09/508,836
• Time in Patent Office: 606 Days
• Field of Search: 427/131, 427/249.1, 427/255.28, 427/209, 427/570, 427/577, 427/580, 427/585, 427/595
• US Class Current: 427/570
• CPC Class Codes: C23C 16/26 Deposition of carbon only
• CPC Class Codes: G11B 5/7257 Perfluoropolyether lubricant
• CPC Class Codes: G11B 5/7266 comprising a lubricant over the inorganic carbon coating
• CPC Class Codes: G11B 5/8408 protecting the magnetic layer
• CPC Class Codes: G11B 5/85 Coating a support with a magnetic layer by vapour deposition

Abstract

The present invention provides a method for manufacturing a magnetic recording medium comprising the steps of forming a carbon protective film onto a disc, the non-magnetic substrate of which is layered with a non-magnetic base film and magnetic film, using a reactant gas containing carbon atoms as a starting material, according to a plasma CVD method, wherein a mixed gas of hydrocarbon and hydrogen, in which the mixing ratio of hydrocarbon to hydrogen is in the range of 2 to 1˜1 to 100 by volume, is used as a reactant gas, during bias applying to said disc. In addition, the present invention provides a magnetic recording medium comprising a carbon protective film formed onto a disc, the non-magnetic substrate of which is layered with a non-magnetic base film and magnetic film, wherein said carbon protective film is formed according to a plasma CVD method, while applying bias.

Claims

1. A method for manufacturing a magnetic recording medium comprising the steps of forming a carbon protective film onto a disc, the non-magnetic substrate of which is layered with a non-magnetic base film and magnetic film, using a reactant gas containing carbon atoms as a starting material, according to a plasma CVD method, wherein a mixed gas of hydrocarbon and hydrogen, in which the mixing ratio of hydrocarbon to hydrogen is in the range of 2 to 1˜

1 to 100 by volume, is used as a reactant gas, while applying a bias to said disc.

2. A method for manufacturing a magnetic recording medium according to claim 1, wherein toluene is used as said hydrocarbon.

3. A method for manufacturing a magnetic recording medium according to claim 2, wherein a mixed gas of toluene and hydrogen, in which the mixing ratio of toluene and hydrogen is in the range of 1 to 15˜

1 to 20 by volume, is used as said reactant gas.

4. A method for manufacturing a magnetic recording medium according to one of claims 1˜

3, wherein said carbon protective film is formed according to a plasma CVD method, under high frequency electrical discharge.

5. A method for manufacturing a magnetic recording medium according to claim 4 wherein the phases of electrical power, supplied to each electrode arranged on the respective sides of said disc, are different from each other at the time of forming said carbon protective film simultaneously, on both sides of said disc, under high frequency electrical discharge.

6. A method for manufacturing a magnetic recording medium according to one of claims 1˜

3, wherein high frequency bias is used as said bias.

7. A method for manufacturing a magnetic recording medium according to claim 6 wherein said carbon protective film is formed according to a plasma CVD method, under high frequency electrical discharge.

8. A method for manufacturing a magnetic recording medium according to claim 7, wherein the phases of electrical power, supplied to each electrode arranged on the respective sides of said disc, are different from each other, at the time of forming said carbon protective film simultaneously, on both sides of said disc, under high frequency electrical discharge.