Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
METHOD FOR PURIFYING LUBRICANT AND MAGNETIC DISK HAVING MEMBRANE OF LUBRICANT OBTAINED FROM THE PURIFICATION METHOD
Document Type and Number:
Japanese Patent JP2003041279
Kind Code:
A
Abstract:

To provide a purification method which can reduce the number of times of solvent extraction in purifying a perfluoropolyether having a hydroxy group at the terminal.

In removing a low molecular weight component from a lubricant to purify it for the lubricating film 11 of a magnetic disc 1 obtained by forming, on the surface of a non-magnetic disc substrate 3, an undercoat membrane 5, a magnetic layer 7, a protective membrane 9, and a lubricating membrane 11 in the order named, a perfluoropolyether having a hydroxy group in the terminal is subjected to solvent extraction with the use of a solvent comprising a 5C completely fluorinated carbon fluoride as the major component as the good solvent and ethyl alcohol or methyl alcohol as the poor solvent. By this, the number of times of solvent extraction can be reduced in the purification of a perfluoropolyether having a hydroxy group at the terminal which becomes a lubricant.


Inventors:
ISHIDA MINA
NAKAKAWAJI TAKAYUKI
MATSUMOTO HIROYUKI
TANI KOUJI
Application Number:
JP2001226513A
Publication Date:
February 13, 2003
Filing Date:
July 26, 2001
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
HITACHI LTD
International Classes:
C10M107/38; C10M177/00; G11B5/725; G11B5/82; C10N20/04; C10N40/18; C10N70/00; (IPC1-7): C10M107/38; C10M177/00; G11B5/725; G11B5/82
Attorney, Agent or Firm:
Hirotsugu Yoshioka