Fluorinated composition, method of coating the composition, and article thereby

1. A fluorinated composition comprising:

(a) from 51 to 95 parts by weight of a first polyfluoropolyether silane represented by the formula:

R fa O(CF(CF 3 )CF 2 O) p CF(CF 3 )CH 2 OZ 1 Si(Y 1 ) 3

wherein:

Z 1 represents —R 1 —S—R 2 —, —R 1 —S(═O)—R 2 —, or —R 1 —S(═O) 2 —R 2 , wherein R 1 and R 2 independently represent alkylene groups having from 1 to 12 carbon atoms;

each Y 1 independently represents a hydrolyzable group; and

R fa represents a perfluoroalkyl group having from 1 to 12 carbon atoms, optionally substituted with at least one catenated oxygen atom or —NR 8 —group, wherein R 8 represents a perfluoroalkyl group;

p is a number in a range of from 3 to 50; and

(b) from 5 to 49 parts by weight of a second polyfluoropolyether silane represented by formula:

R fb [R 5 CH 2 OZ 2 Si(Y 2 ) 3 ] 2

wherein:

each Z 2 independently represents —R 3 —S—R 4 —, —R 3 —S(═O)—R 4 —, or —R 3 S(═O) 2 —R 4 , wherein R 3 and R 4 independently represent alkylene groups having from 1 to 12 carbon atoms;

each Y 2 independently represents a hydrolyzable group;

each R 5 independently represents a covalent bond, or —(OR 7 ) b —, wherein each R 7 independently represents a branched perfluoroalkylene group, and each b independently represents a number greater than or equal to one; and

R fb represents a perfluoroalkylene group having at least 3 carbon atoms, optionally substituted with at least one catenated oxygen atom or —NR 6 —group, wherein R 6 represents a perfluoroalkyl group,

wherein the parts by weight of the first polyfluoropolyether silane and the second polyfluoropolyether silane are based on the total parts of the first polyfluoropolyether silane and the second polyfluoropolyether silane combined.

2. The fluorinated composition of claim 1 , wherein the second polyfluoropolyether silane is represented by the formula:

(Y 2 ) 3 SiZ 2 OCH 2 CF 2 R 9 CF 2 CH 2 OZ 2 Si(Y 2 ) 3

wherein R 9 is a divalent group consisting of from 1 to 50—OCF 2 —groups randomly interspersed with from 3 to 40 —OCF 2 —groups.

3. The fluorinated composition of claim 1 , wherein Z 1 is a divalent group represented by the formula:

—R 1 SR 2 —

and wherein each of R 1 and R 2 independently represents an alkylene group having from 1 to 12 carbon atoms.

4. The fluorinated composition of claim 1 , wherein Z 1 is —CH 2 CH 2 CH 2 SCH 2 CH 2 CH 2 —.

5. The fluorinated composition of claim 1 , wherein Z 2 is a divalent group represented by the formula:

—R 3 SR 2 —

and wherein each of R 3 and R 4 independently represents an alkylene group having from 1 to 12 carbon atoms.

6. The fluorinated composition of claim 1 , wherein Z 2 is —CH 2 CH 2 CH 2 SCH 2 CH 2 CH 2 —.

7. The fluorinated composition of claim 1 , wherein the fluorinated composition comprises from 60 to 95 parts by weight of the first polyfluoropolyether silane based on a combined weight of the first and second polyfluoropolyether silanes.

8. The fluorinated composition of claim 1 , wherein the fluorinated composition comprises from 65 to 75 parts by weight of the first polyfluoropolyether silane.