Fluoropolyether group-containing compound

1. A surface-treating agent comprising a fluoropolyether group-containing compound represented by formula (1) and a fluoropolyether group-containing compound represented by formula (2) below:

wherein

R F1 is R f1 —R F —O q —;

R F2 is —R f2 p —R F —O q —;

R f1 is a C 1-16 alkyl group optionally substituted with one or more fluorine atoms;

R f2 is a C 1-6 alkylene group optionally substituted with one or more fluorine atoms;

R F is each independently at each occurrence a group represented by formula:

—(OC 6 F 12 ) a —(OC 5 F 10 ) b —(OC 4 F 8 ) c —(OC 3 R Fa 6 ) d —(OC 2 F 4 ) e —(OCF 2 ) f —

a, b, c, and d are each independently an integer of 0 or more and 30 or less, e and f are each independently an integer of 1 or more and 200 or less, the sum of a, b, c, d, e, and f is at least 5, the occurrence order of each repeating unit enclosed in parentheses provided with a subscript a, b, c, d, e, or f is not limited in the formula, and the ratio of e to f is less than 0.9;

R Fa is each independently at each occurrence a hydrogen atom, a fluorine atom, or a chlorine atom;

p is 0 or 1;

q is independently 0 or 1;

R Si is each independently at each occurrence represented by formula (S1) below:

—X 1 —SiR a1 p1 R b1 q1 R c1 r1   (S1)

X 1 is each independently at each occurrence a single bond, an oxygen atom, or a divalent organic group;

R a1 is each independently at each occurrence —Z 1′ —SiR a1′ p1′ R b1′ q1′ R d1′ r1′ ;

Z 1′ is each independently at each occurrence a single bond, an oxygen atom, or a divalent organic group;

R a1′ is each independently at each occurrence —Z 1″ —SiR a1″ p1″ R b1″ q1″ R c1″ r1″ ;

Z 1″ is each independently at each occurrence a single bond, an oxygen atom, or a divalent organic group;

R a1″ is each independently at each occurrence —Z 1′″ —SiR b1′″ q1′″ R c1′″ r1′″ ;

Z 1′″ is each independently at each occurrence a single bond, an oxygen atom, or a divalent organic group;

R b41′″ is each independently at each occurrence a hydroxyl group or a hydrolyzable group;

R c1′″ is each independently at each occurrence a hydrogen atom or a monovalent organic group;

q1′″ is each independently at each occurrence an integer of 0 to 3;

r1′″ is each independently at each occurrence an integer of 0 to 3;

R b1″ is each independently at each occurrence a hydroxyl group or a hydrolyzable group;

R c1″ is each independently at each occurrence a hydrogen atom or a monovalent organic group;

p1″ is each independently at each occurrence an integer of 0 to 3;

q1″ is each independently at each occurrence an integer of 0 to 3;

r1″ is each independently at each occurrence an integer of 0 to 3;

R b1′ is each independently at each occurrence a hydroxyl group or a hydrolyzable group;

R c1′ is each independently at each occurrence a hydrogen atom or a monovalent organic group;

p1′ is each independently at each occurrence an integer of 0 to 3;

q1′ is each independently at each occurrence an integer of 0 to 3;

r1′ is each independently at each occurrence an integer of 0 to 3;

R b1 is each independently at each occurrence a hydroxyl group or a hydrolyzable group;

R c1 is each independently at each occurrence a hydrogen atom or a monovalent organic group;

p1 is each independently at each occurrence an integer of 0 to 3;

q1 is each independently at each occurrence an integer of 0 to 3; and

r1 is each independently at each occurrence an integer of 0 to 3;

provided that at least one R b1 , R b1′ , R b1″ , or R b1′″ is present for each group represented by R Si .

2. The surface treating agent according to claim 1 , wherein R F is represented by:

—(OC 4 F 8 ) c —(OC 3 F 6 ) d —(OC 2 F 4 ) e —(OCF 2 ) f —

wherein

c and d are each independently an integer of 0 or more and 30 or less, e and f are each independently an integer of 1 or more and 200 or less, and the occurrence order of each repeating unit enclosed in parentheses provided with a subscript c, d, e, or f is not limited in the formula.

3. The surface treating agent according to claim 1 , wherein the ratio of e to f is in a range of 0.4 or more and less than 0.9.

4. The surface treating agent according to claim 1 , wherein X 1 is each independently at each occurrence a divalent organic group.

5. The surface treating agent according to claim 1 , wherein x 1 is each independently at each occurrence:

—(Z 21 ) z11 —(X 2 ) z12 —(Z 22 ) z13 —

wherein Z 21 and Z 22 are a divalent organic group;

X 2 is an oxygen atom;

z11 is 0 or 1;

z12 is 0 or 1; and

z13 is 0 or 1,

provided that at least one of z11 and z13 is 1.

6. The surface treating agent according to claim 1 , wherein R Fa is a fluorine atom.

7. The surface treating agent according to claim 1 , wherein p1 is 0, and q1 is 2 or 3.