Lubricant composition, fluorine-based compound, and use thereof

A fluorine-based compound represented by following formula (1):

• where X represents a cyclic group which may be substituted;
• Y represents a divalent or higher-valent linking group having at least one polar group and having no aromatic cyclic group;
• p1 represents an integer of 1 to 4;
• p2, p3, and p4 each represents an integer of 0 to 4;
• q represents an integer of 0 to 30;
• n represents an integer of 1 to 10;
• s represents an integer of 1 to 4;
• and t represents an integer of 2 to 10, provided that the binding sequence of —(CF2)p1—, —(CF)p2—, —[CF(CF3)]p3—, and —[C(CF3)2]p4— that constitute —{(CF2)p1(CF)p2[CF(CF3)]p3[C(CF3)2]p4O}— in the formula (1) is not limited, and —{(CF2)p1(CF)p2[CF(CF3)]p3[C(CF3)2]p4O}— means a perfluoroalkyleneoxy group in which a perfluoroalkylene unit selected from —(CF2)p1—, —(CF)p2—, —[CF(CF3)]p3—, and —[C(CF3)2]p4— and an oxygen atom are distributed randomly;
• when q is 2 or more, a plurality of —{(CF2)p1(CF)p2[CF(CF3)]p3[C(CF3)2]p4O}— may be the same as or different from each other;
• when s is 2 or more, a plurality of n's and q's may be the same as or different from each other;
• and when t is 2 or more, a plurality of s's and Y's may be the same as or different from each other;
• and when p2 is 1 or more, the perfluoroalkyleneoxy group has a branched structure.

A fluorine-based compound represented by any of following formulae (1a) to (1f):

• where, in the formulae, X represents a cyclic group which may be substituted;
• W1 and W2 each represents a polar group, or a group having a polar group including one or more polar groups, one or more methylene groups (CH2), one or more methine groups (CH), one or more quaternary carbon atoms, or a group formed by combination of two or more thereof;
• k represents 0 or 1;
• L1 to L3 each represents —CH2—, —OCH2—, —CH2O—, or —C(═O)—;
• Z represents an oxygen atom or NH;
• m represents an integer of 2 to 4;
• n represents an integer of 1 to 10;
• t represents an integer of 2 to 10;
• and q represents an integer of 1 to 30, provided that a plurality of L1 to L3, k, W1, W2, Z, m, n, and q each present in the formula may be the same as or different from each other.

A fluorine-based compound represented by any of following formulae (1g) to (1l):

• where in the formulae, X represents a cyclic group which may be substituted;
• W1 and W2 each represents a polar group, or a group having a polar group including one or more polar groups, one or more methylene groups (CH2), one or more methine groups (CH), one or more quaternary carbon atoms, or a group formed by combination of two or more thereof;
• k represents 0 or 1;
• L1 to L3 each represents —CH2—, —OCH2—, —CH2O—, or —C(═O)—;
• Z represents an oxygen atom or NH;
• v represents an integer of 1 to 20;
• and w represents an integer of 1 to 20, provided that (v+w) is an integer of 1 to 30;
• the binding sequence of (CF2O) and (CF2CF2O) is not limited;
• n represents an integer of 1 to 10;
• and t represents an integer of 2 to 10, provided that a plurality of L1 to L3, k, W1, W2, Z, v, w, and n each present in the formula may be the same as or different from each other.