Patent ID: 8053538

Claim:
An ether composition comprising a polyether compound (A) containing at least three —(OCF 2 CF 2 )— units, containing no —OCF 2 O— structure and having an average molecular weight of higher than 2,000 and at most 20,000, and an ether compound (B) containing at least one —(OCF 2 CF 2 )— unit and having an average molecular weight of at most 2,000, wherein the polyether compound (A) comprises one or more of compounds represented by the following formula (A-1) having an average molecular weight of higher than 2,000 and at most 20,000 and/or one or more of compounds represented by the following formula (A-2) having an average molecular weight of higher than 2,000 and at most 20,000: (HOCH 2 CF 2 O(CF 2 CF 2 O) d1 —) 3 Y 3 (A-1) (HOCH 2 CF 2 O(CF 2 CF 2 O) d2 —) 4 Y 4 (A-2) wherein Y 3 is a perfluoroalkane triyl group, Y 4 is a perfluoroalkane tetrayl group, d1 is a positive number of at least 1, and d2 is a positive number of at least 1.