Fluorinated ether compound, fluorinated ether composition and coating liquid, and substrate having surface-treated layer and method for its production

1. A fluorinated ether compound which has a poly(oxyperfluoroalkylene) chain (αβ) having a C 4 oxyperfluoroalkylene unit (α) and an oxyperfluoroalkylene unit (β) other than the unit (α) and which has a hydrolysable silyl group on at least one terminal of the poly(oxyperfluoroalkylene) chain (αβ) via a linking group.

2. The fluorinated ether compound according to claim 1 , wherein in the poly(oxyperfluoroalkylene) chain (αβ), the unit (α) and the unit (β) are alternately arranged.

3. The fluorinated ether compound according to claim 1 , wherein a C 1-6 perfluoroalkyl group is bonded via an oxygen atom to the carbon atom at one end of the poly(oxyperfluoroalkylene) chain (αβ), and the hydrolysable silyl group is bonded via the linking group to the oxygen atom at the other end of the poly(oxyperfluoroalkylene) chain (αβ).

4. The fluorinated ether compound according to claim 3 , wherein in the poly(oxyperfluoroalkylene) chain (αβ), the unit (α) and the unit (β) are alternately arranged and wherein the perfluoroalkyl group is bonded to the carbon atom of the unit (β), and the hydrolysable silyl group is bonded via the linking group to the oxygen atom of the unit (α).

5. The fluorinated ether compound according to claim 1 , which has a number average molecular weight of from 2,000 to 10,000.

6. The fluorinated ether compound according to claim 1 , wherein the unit (α) is (CF 2 CF 2 CF 2 CF 2 O).

7. A fluorinated ether composition containing at least 95 mass % of the fluorinated ether compound as defined in claim 1 .

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

9. The coating liquid according to claim 8 , wherein the medium contains at least one organic solvent selected from the group consisting of a fluorinated alkane, a fluorinated aromatic compound and a fluoroalkyl ether.

10. A method for producing a substrate having a surface-treated layer, which comprises a step of applying the fluorinated ether compound as defined in claim 1 or a fluorinated ether composition containing at least 95 mass % of the fluorinated ether compound to the surface of a substrate by vacuum vapor deposition.

11. A method for producing a substrate having a surface-treated layer, which comprises a step of applying the coating liquid as defined in claim 8 to the surface of a substrate, followed by dying.

12. The method for producing a substrate having a surface-treated layer according to claim 11 , wherein the method of applying the coating liquid to the surface of the substrate is a spin coating method, a wipe coating method, a spray coating method, a squeegee coating method, a dip coating method, a die coating method, an ink jet method, a flow coating method, a roll coating method, a casting method, a Langmuir-Blodgett method or a gravure coating method.

13. The method for producing a substrate having a surface-treated layer according to claim 10 , wherein the material for the substrate is a metal, a resin, glass, a ceramic or a composite material thereof.

14. The method for producing a substrate having a surface-treated layer according to claim 11 , wherein the material for the substrate is a metal, a resin, glass, a ceramic or a composite material thereof.

15. A substrate having a surface-treated layer, obtained by treatment with the fluorinated ether composition as defined in claim 7 .

16. A touch panel having, on its input screen, the substrate having a surface-treated layer, obtained by treatment with the fluorinated ether composition as defined in claim 7 .

17. The fluorinated ether compound according to claim 1 , wherein the unit (β) is (CF 2 CF 2 O).

18. The fluorinated ether compound according to claim 17 , which has a number average molecular weight of from 2,000 to 10,000.

19. The fluorinated ether compound according to claim 6 , wherein the unit (β) is (CF 2 CF 2 O).

20. The fluorinated ether compound according to claim 19 , which has a number average molecular weight of from 2,000 to 10,000.

21. The fluorinated ether compound according to claim 6 , which has a number average molecular weight of from 2,000 to 10,000.

22. The fluorinated ether compound according to claim 2 , wherein the unit (α) is (CF 2 CF 2 CF 2 CF 2 O).

23. The fluorinated ether compound according to claim 22 , wherein the unit (β) is (CF 2 CF 2 O).

24. The fluorinated ether compound according to claim 23 , which has a number average molecular weight of from 2,000 to 10,000.

25. The fluorinated ether compound according to claim 22 , which has a number average molecular weight of from 2,000 to 10,000.

26. The fluorinated ether compound according to claim 2 , wherein the unit (β) is (CF 2 CF 2 O).

27. The fluorinated ether compound according to claim 26 , which has a number average molecular weight of from 2,000 to 10,000.

28. The fluorinated compound according to claim 1 , which is represented by the following formula (1):

A-O-[(R f1 O) x1 (R f2 O) x2 ]-B  (1)

wherein

x1 and x2 are each independently an integer of at least 1,

R fl is a C 4 perfluoroalkylene group,

Rf 2 is at least one type of a perfluoroalkylene group other than one having 4 carbon atoms, and

A is a C 1-6 perfluoroalkyl group or B

B is a group represented by one of the following formulae (2-1) to (2-5):

—R f3 CX 2 O(CH 2 ) 3 -SiL m R 3-m   (2-1)

—Rf f3 CX 2 OCH 2 CH(CH 3 )-SiL m R 3-m   (2-2)

—R f3 C(═O)NHC k H 2k -SiL m R 3-m   (2-3)

—R f3 (CH 2 ) 2 -SiL m R 3-m   (2-4)

—R f3 (CH 2 ) 3 -SiL m R 3-m   (2-5)

wherein:

R f3 is a C 1-20 perfluoroalkylene group,

X is a hydrogen atom or a fluorine atom,

L is a hydrolysable group,

R is a hydrogen atom or a monovalent hydrocarbon group,

K is an integer of at least 1, and

m is an integer of from 1 to 3.