Lubricant suitable for use with magnetic disk

摘要

A lubricant according to one embodiment includes a first ingredient and a second ingredient, said first ingredient as the main constituent being a first perfluoropolyether compound represented by the formula (1) which has a weight-average molecular weight of 500 to 6000 and a dispersity smaller than 1.3, and said second ingredient being a second perfluoropolyether compound which has a weight-average molecular weight of 500 to 6000 and has 6 to 10 hydroxyl groups (on average) in one molecule,Rt-Rf¹-Rt   (1)where, Rf¹ denotes a perfluoropolyether chain represented by the formula (2) and Rt denotes a terminal group represented by the formula (3),—CF₂O—[(CF₂CF₂O)_m—(CF₂O)_n]—CF₂—  (2)where, m and n each denote a natural number,;