Composition, magnetic recording medium, head slider, and magnetic recording device

2222p2q22There are provided a composition that exhibits sufficient flowability and also displays high substrate adhesion, and a magnetic recording medium, a head slider and a magnetic recording device that use this composition as a lubricant and are thus not prone to faults. The composition comprises a fluorine-containing polyether represented by formula (1), (in formula (1), p and q represent, independently of the symbols in other formulae, any chosen integers). The composition can be produced by reacting a polymer represented by formula (2) with glycidol, HOCHCFO(CFCFO)(CFO)CFCHOH (2) (in formula (2), p and q represent, independently of the symbols in other formulae, any chosen integers).