Fluorinated ether compound, coating liquid, article and novel compounds

1. A fluorinated ether compound represented by the following formula (1):

[R f -G-] a Z[—(O—R 2 ) c —SiR 3 n L 3−n ] b   (1)

wherein R f is a linear polyfluoroalkyl group having at least two carbon atoms, which has at least one etheric oxygen between carbon-carbon atoms and has at least one fluorine atoms on a carbon atom bonded to G or Z,

G is —R 1 —O—, —R 1 —CONH—, —CONH— or a single bond,

R 1 is an alkylene group,

Z is a hydrocarbon group having a valence of (a+b) or a hydrocarbon group having at least two carbon atoms, having at least one etheric oxygen atom between carbon-carbon atoms and having a valence of (a+b),

R 2 is an alkylene group,

R 3 is a hydrogen atom or a monovalent hydrocarbon group,

L is a hydrolyzable group,

n is an integer of from 0 to 2,

a is an integer of at least 1,

b is an integer of at least 1,

(a+b) is at least 3,

when a is 1, b is at least 4, and when a is at least 2, b is at least 1,

provided that when a is at least 2, each [R f -G-] may be identical with or different from one another, and

when b is at least 2, each [—(O—R 2 )—SiR 3 n L 3−n ] may be identical with or different from one another, and

c is 0 or 1.

2. The fluorinated ether compound according to claim 1 , wherein c is 1 and R 2 is a C 4-14 alkylene group.

3. The fluorinated ether compound according to claim 1 , wherein Z is a group represented by the following formula (Z-1), a group represented by the following formula (Z-2), a group represented by the following formula (Z-3), a group represented by the following formula (Z-4) or a group represented by the following formula (Z-5):

wherein R 4 is an alkyl group.

4. The fluorinated ether compound according to claim 1 , wherein R 1 is —CH 2 —.

5. The fluorinated ether compound according to claim 1 , wherein R f is a group represented by the following formula (R f -0):

R f1 O(R f2 O) m1 (R f3 O) m2 R f4 —  (R f -0)

wherein when m1 is 0, R f is a C 1-20 linear perfluoroalkyl group, and when m1 is at least 1, R f1 is a C 1-20 linear perfluoroalkyl group or a C 2-20 linear perfluoroalkyl group having at least one etheric oxygen atom between carbon-carbon atoms,

R f2 is a C 1-10 linear fluoroalkylene group having at least one hydrogen atom,

m1 is an integer of from 0 to 10, provided that when m1 is at least 2, (R f2 O) m1 may be composed of at least two kinds of R f2 O different in either or both of the number of carbon atoms and the number of hydrogen atoms,

R f3 is a C 1-10 linear perfluoroalkylene group,

m2 is an integer of from 2 to 200, provided that (R f3 O) m2 may be composed of at least two kinds of R f3 O different in the number of carbon atoms, and

R f4 is a C 1-10 linear perfluoroalkylene group.

6. The fluorinated ether compound according to claim 1 , wherein R f is a linear perfluoroalkyl group having at least two carbon atoms and having at least one etheric oxygen atoms between carbon-carbon atoms.

7. The fluorinated ether compound according to claim 1 , wherein R f is a group represented by the following formula (R f -1), a group represented by the following formula (R f -2) or a group represented by the following formula (R f -3):

R f1 O{(CF 2 O) m21 (CF 2 CF 2 O) m22 }CF 2 —  (R f -1)

R f1 OCHFCF 2 OCH 2 CF 2 O{(CF 2 O) m21 (CF 2 CF 2 O) m22 }CF 2 —  (R f -2)

R f1 O(CF 2 CF 2 OCF 2 CF 2 CF 2 CF 2 O) m25 CF 2 CF 2 OCF 2 CF 2 CF 2 —  (R f -3)

wherein R f1 is a C 1-20 perfluoroalkyl group,

each of m21 and m22 is an integer of at least 1, m21+m22 is an integer of from 2 to 200, provided that each CF 2 O and each CF 2 CF 2 O may be bonded in any order, and

m25 is an integer of from 1 to 100.

8. The fluorinated ether compound according to claim 1 , which has a number average molecular weight of from 1,000 to 30,000.

9. A coating liquid comprising the fluorinated ether compound as defined in claim 1 and a liquid medium.

10. A process for producing an article having a surface layer formed from a fluorinated ether compound, which comprises treating the surface of a substrate with the coating liquid as defined in claim 9 by wet coating.

11. An article having a surface layer formed from the fluorinated ether compound as defined in claim 1 .

12. A process for producing an article having a surface layer formed from the fluorinated ether compound as defined in claim 1 , which comprises treating the surface of a substrate with the fluorinated ether compound by dry coating.

13. The fluorinated ether compound according to claim 1 , which is represented by one of the following formulae: