Magnetic recording medium

• US 5,786,074 A
• Filed: 05/31/1996
• Issued: 07/28/1998
• Est. Priority Date: 01/18/1994
• Status: Expired due to Term

• Current Assignee: Hitachi Maxell Limited (Maxell, Ltd.)
• Original Assignee: Hitachi Maxell Limited (Maxell, Ltd.)
• Inventors: Soui, Tadashi
• Primary Examiner(s): Resan, Stevan A.
• Application Number:
  US08/655,927
• Time in Patent Office: 788 Days
• Field of Search: 428/323, 428/328, 428/341, 428/536, 428/694 BP, 428/900
• US Class Current: 428/323
• CPC Class Codes: G11B 5/70 on a base layer
• CPC Class Codes: G11B 5/71 characterised by the lubricant
• CPC Class Codes: Y10S 428/90 Magnetic feature
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/256 Heavy metal or aluminum or compound thereof
• CPC Class Codes: Y10T 428/273 of coating
• CPC Class Codes: Y10T 428/31986 Regenerated or modified

Abstract

A magnetic recording medium having excellent reliability with minimum drop-out including a support film and a magnetic layer containing magnetic powder particles dispersed in a binder resin and a lubricant having a total extract content of from 10 to 100 mg/m² and a content at the surface of the magnetic layer not larger than 1.0 mg/m².

Claims

1. A magnetic recording medium including a support film and a magnetic layer comprising magnetic powder particles dispersed in a binder resin and a lubricant, wherein total extract content of said lubricant in said magnetic layer is from 10 to 100 mg/m² while the content of said lubricant at the surface of said magnetic layer is not greater than 1.0 mg/m² as measured by ESCA including measuring C1s photoelectron spectrum of said lubricant and C1s photoelectron spectrum of said magnetic layer before and after washing a surface of said magnetic layer by normal hexane.

2. The magnetic recording medium according to claim 1, wherein said lubricant is selected from at least one member of the group consisting of fatty acids and fatty acid esters.

3. The magnetic recording medium according to claim 1, wherein said binder resin comprises nitrocellulose.

4. The magnetic recording medium according to claim 1, wherein said magnetic layer further includes additives having a high Moh'"'"'s hardness being selected from at least one member of the group consisting of α

Al₂ O₃ and Cr₂ O₃.

5. The magnetic recording medium as in claim 4, wherein said additive is present in an amount of more than 5% by weight based on the weight of the magnetic powder.

6. A magnetic recording medium including a support film and a magnetic layer comprising magnetic powder particles dispersed in a binder resin and a lubricant, wherein total extract content of said lubricant in said magnetic layer is from 10 to 100 mg/m² while the content of said lubricant at the surface of said magnetic layer is not greater than 1.0 mg/m² as measured by ESCA including measuring C1s photoelectron spectrum of said lubricant and C1s photoelectron spectrum of said magnetic layer before and after washing a surface of said magnetic layer by normal hexane, wherein said lubricant is Oleyl oleate.