Patent ID: 7105241

Claim:
A method of manufacturing magnetic disks comprising a magnetic layer, a carbon-base protective layer, and a lubricating layer on a substrate, said lubricating layer including —COOH and/or —CF 2 COOH atomic groups, said method comprising preparing lubricant c by mixing lubricant a and lubricant b; wherein lubricant a is prepared from a lubricant alpha comprising a compound denoted by chemical formula HO—CH 2 —CH(OH)—CH 2 —O—CH 2 —CF 2 (—O—C 2 F 4 ) p -(O—CF 2 ) q -O—CF 2 —CH 2 —O—CH 2 —CH(OH)—CH 2 —OH [Chem. 1] wherein p and q are natural number, and a compound denoted by chemical formula HO—CH 2 —CF 2 (—O—C 2 F 4 ) m -(O—CF 2 ) n -O—CF 2 —CH 2 —OH [Chem. 2] wherein m and n are natural number, are fractionated by molecular weight to prepare the lubricant a having a weight average molecular weight (Mw) of from 3,000 to 7,000 and a molecular weight dispersion of less than or equal to 1.2; a lubricant beta prepared from a compound denoted by the chemical formula HO—CH 2 —CF 2 (—O—C 2 F 4 ) m -(O—CF 2 ) n -O—CF 2 —CH 2 —OH [Chem. 3] wherein m and n are natural number, fractionated by molecular weight to prepare the lubricant b having a weight average molecular weight (Mw) of from 2,000 to 5,000 and a molecular weight dispersion of less than or equal to 1.2; and a film of lubricant c is formed on the carbon—base protective layer to form the lubricating layer.