SURFACE-TREATING AGENT

1 . A surface-treating agent comprising:

(1) a fluoroalkylsilane oligomer mixture; and

(2) a perfluoroalkyl group-containing silane compound,

wherein the fluoroalkylsilane oligomer mixture comprises a partially hydrolyzed condensate of a fluoroalkylsilane compound represented by the following formula (I):

R f1 -Q 1 -SiR 1 p X 1 3−p   (I)

wherein

R f1 is C l F 2l+1 ;

l is an integer of 1 to 10;

Q 1 is a single bond or a divalent hydrocarbon group having 1 to 6 carbon atoms;

R 1 is each independently a monovalent hydrocarbon group having 1 to 6 carbon atoms;

X 1 is each independently a hydroxyl group or a hydrolyzable group; and

p is an integer of 0 to 2, and

the perfluoroalkyl group-containing silane compound is a compound represented by the following formula (II):

[A] b1 Q 2 [B] b2   (II)

wherein

Q 2 is a linking group having a valence of (b1+b2);

A is a group represented by R f3 —O—R f2 —;

R f2 is a poly(oxyfluoroalkylene) chain;

R f3 is a perfluoroalkyl group;

B is a monovalent group having one —R 12 —(SiR 2 r X 2 3−r ) and no fluorine atoms;

R 12 is a hydrocarbon group having 2 to 10 carbon atoms which optionally have an ethereal oxygen atom between carbon atoms or at the end opposite the end to which Si is bonded, or optionally have —NH— between carbon atoms;

R 2 is each independently a hydrogen atom or an optionally substituted monovalent hydrocarbon group having 1 to 6 carbon atoms;

X 2 is each independently a hydroxyl group or a hydrolyzable group;

r is an integer of 0 to 2;

Q 2 and B do not contain a cyclic siloxane structure;

b1 is an integer of 1 to 3; and

b2 is an integer of 2 to 9;

provided that, when b1 is two or more, b1 number of A may be the same or different, and b2 number of B may be the same or different.

2 . The surface-treating agent according to claim 1 , wherein R f2 in the formula (II) is a group represented by —(C a F 2a O) n —, wherein a is an integer of 1 to 6, n is an integer of 2 or more, and each —C a F 2a O— unit may be the same or different.

3 . The surface-treating agent according to claim 1 , wherein R f2 in the formula (II) is a group represented by —(CF 2 CF 2 CF 2 CF 2 CF 2 CF 2 O) n1 —(CF 2 CF 2 CF 2 CF 2 CF 2 O) n2 —(CF 2 CF 2 CF 2 CF 2 O) n3 —(CF 2 CF 2 CF 2 O) n4 —(CF(CF 3 )CF 2 O) n5 —(CF 2 CF 2 O) n6 —(CF 2 O) n7 —

wherein n1, n2, n3, n4, n5, n6, and n7 are each independently an integer of 0 or more, the sum of n1, n2, n3, n4, n5, n6, and n7 is 2 or more, and each repeating unit may be present in a block, alternating, or random manner.

4 . The surface-treating agent according to claim 1 , wherein the fluoroalkylsilane compound represented by the formula (I) is a compound represented by the formula (I-1) or (I-2)

CF 3 (CF 2 ) 1-1 —(CH 2 ) t —SiX 1 3   (I-1)

CF 3 (CF 2 ) 1-1 —(CH 2 ) t —SiR 1 X 1 2   (I-2)

wherein l is an integer of 1 to 10, t is an integer of 1 to 6, and X 1 and R 1 have the same meaning as described in claim 1 .

5 . A surface-treating agent comprising:

(1) a fluoroalkylsilane oligomer mixture; and

(2) a perfluoroalkyl group-containing silane compound,

wherein the fluoroalkylsilane oligomer mixture comprises a partially hydrolyzed condensate of a fluoroalkylsilane compound represented by the following formula (I):

R f1 -Q 1 -SiR 1 p X 1 3−p   (I)

wherein

R f1 is C l F 2l+1 ;

l is an integer of 1 to 10;

Q 1 is a single bond or a divalent hydrocarbon group having 1 to 6 carbon atoms;

R 1 is each independently a monovalent hydrocarbon group having 1 to 6 carbon atoms;

X 1 is each independently a hydroxyl group or a hydrolyzable group; and

p is an integer of 0 to 2, and

the perfluoroalkyl group-containing silane compound is a compound represented by any of the following formulae (A1), (A2), (B1), (B2), (C1), and (C2):

(Rf-PFPE) γ′ -X 5 —(SiR 21 n1 R 22 3−n1 ) β   (A1)

(R 22 3−n1 R 21 n1 Si) β —X 5 -PFPE-X 5 —(SiR 21 n1 R 22 3−n1 ) β   (A2)

(Rf-PFPE) γ′ -X 7 —(SiR a k1 R b l1 R c m1 ) γ   (B1)

(R c m1 R b l1 R a k1 Si) γ —X 7 -PFPE-X 7 —(SiR a k1 R b l1 R c m1 ) γ   (B2)

(Rf-PFPE) δ′ -X 9 —(CR d k2 R e l2 R f m2 ) δ   (C1)

(R f m2 R e l2 R d k2 C) δ —X 9 -PFPE-X 9 —(CR d k2 R e l2 R f m2 ) δ   (C2)

wherein

PFPE is each independently at each occurrence a group represented by formula:

—(OC 4 F 8 ) a —(OC 3 F 6 ) b —(OC 2 F 4 ) c —(OCF 2 ) d —

wherein a, b, c, and d are each independently an integer of 0 to 200, the sum of a, b, c, and d is at least 1, and the occurrence order of the respective repeating units enclosed in parentheses provided with subscripts a, b, c, and d is not limited in the formula;

Rf is each independently at each occurrence an alkyl group having 1 to 16 carbon atoms, optionally substituted with one or more fluorine atoms;

R 21 is each independently at each occurrence a hydroxyl group or a hydrolyzable group;

R 22 is each independently at each occurrence a hydrogen atom or an alkyl group having 1 to 22 carbon atoms;

n1 is an integer of 0 to 3 independently in each (—SiR 21 n1 R 22 3−n1 ) unit;

provided that at least one n1 in formulae (A1) and (A2) is an integer of 1 to 3;

X 5 each independently represents a single bond or a di- to decavalent organic group;

β is each independently an integer of 1 to 9;

β′ is each independently an integer of 1 to 9;

X 7 each independently represents a single bond or a di- to decavalent organic group;

γ is each independently an integer of 1 to 9;

γ′ is each independently an integer of 1 to 9;

R a is each independently at each occurrence —Z 1 —SiR 71 p1 R 72 q1 R 73 r1 ;

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

R 71 is each independently at each occurrence R a′ ;

R a′ has the same meaning as R a ;

in R a , the number of Si atoms linearly linked via a group Z 1 is at most 5;

R 72 is each independently at each occurrence a hydroxyl group or a hydrolyzable group;

R 73 is each independently at each occurrence a hydrogen atom or a lower alkyl 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;

provided that at least one q1 in formulae (B1) and (B2) is an integer of 1 to 3;

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

R c is each independently at each occurrence a hydrogen atom or a lower alkyl group;

k1 is each independently at each occurrence an integer of 1 to 3;

l1 is each independently at each occurrence an integer of 0 to 2;

m1 is each independently at each occurrence an integer of 0 to 2;

provided that, in the unit enclosed in parentheses provided with γ, the sum of k1, l1 and m1 is 3;

X 9 each independently represents a single bond or a di- to decavalent organic group;

δ is each independently an integer of 1 to 9;

δ′ is each independently an integer of 1 to 9;

R d is each independently at each occurrence —Z 2 —CR 81 p2 R 82 q2 R 83 r2 ;

Z 2 is each independently at each occurrence an oxygen atom or a divalent organic group;

R 81 is each independently at each occurrence R d′ ;

R d′ has the same meaning as R d ;

in R d , the number of C atoms linearly linked via a group Z 2 is at most 5;

R 82 is each independently at each occurrence —Y—SiR 85 n2 R 86 3−n2 ;

Y is each independently at each occurrence a divalent organic group;

R 85 is each independently at each occurrence a hydroxyl group or a hydrolyzable group;

R 86 is each independently at each occurrence a hydrogen atom or a lower alkyl group;

n2 represents an integer of 0 to 3 independently in each (—Y—SiR 85 n2 R 86 3−n2 ) unit;

provided that at least one n2 in formulae (C1) and (C2) is an integer of 1 to 3;

R 83 is each independently at each occurrence a hydrogen atom, a hydroxyl group, or a lower alkyl group;

p2 is each independently at each occurrence an integer of 0 to 3;

q2 is each independently at each occurrence an integer of 0 to 3;

r2 is each independently at each occurrence an integer of 0 to 3;

R e is each independently at each occurrence —Y—SiR 85 n2 R 86 3−n2 ;

R f is each independently at each occurrence a hydrogen atom, a hydroxyl group, or a lower alkyl group;

k2 is each independently at each occurrence an integer of 0 to 3;

l2 is each independently at each occurrence an integer of 0 to 3; and

m2 is each independently at each occurrence an integer of 0 to 3;

provided that, in the formulae (C1) and (C2), at least one q2 is 2 or 3 or at least one 12 is 2 or 3.

6 . The surface-treating agent according to claim 5 , wherein Rf is a perfluoroalkyl group having 1 to 16 carbon atoms.

7 . The surface-treating agent according to claim 5 , wherein PFPE is a group represented by any of the following formulae (i) to (iv)

—(OCF 2 CF 2 CF 2 ) b —  (i)

wherein b is an integer of 1 to 200;

—(OCF(CF 3 )CF 2 ) b —  (ii)

wherein b is an integer of 1 to 200;

—(OCF 2 CF 2 CF 2 CF 2 ) a —(OCF 2 CF 2 CF 2 ) b —(OCF 2 CF 2 ) c —(OCF 2 ) d —  (iii)

wherein a and b are each independently an integer of 0 or 1 to 30, c and d are each independently an integer of 1 to 200, and the occurrence order of the respective repeating units enclosed in parentheses provided with subscripts a, b, c, and d is not limited in the formula;

or

—(R 7 —R 8 ) f —  (iv)

wherein R 7 is each independently at each occurrence OCF 2 or OC 2 F 4 , and R 8 is each independently at each occurrence a group selected from OC 2 F 4 , OC 3 F 6 , and OC 4 F 8 , or a combination of two or three groups independently selected from these groups; and

f is an integer of 2 to 100.

8 . The surface-treating agent according to claim 5 , wherein k1 is 3 and q1 in R a is 3.

9 . The surface-treating agent according to claim 5 , wherein 12 is 3 and n2 is 3.

10 . The surface-treating agent according to claim 5 , wherein Y represents a C 1-6 alkylene group, —(CH 2 ) g′ —O—(CH 2 ) h′ —, wherein g′ is an integer of 0 to 6 and h′ is an integer of 0 to 6, or -phenylene-(CH 2 ) i-, wherein i′ is an integer of 0 to 6.

11 . The surface-treating agent according to claim 5 , wherein X 5 , X 7 , and X 9 are each independently a di- to tetravalent organic group, β, γ and δ are each independently 1 to 3, and β′, γ′ and δ′ are 1.

12 . The surface-treating agent according to claim 5 , wherein X 5 , X 7 , and X 9 are a divalent organic group, β, γ and δ are 1, and β′, γ′ and δ′ are 1.

13 . The surface-treating agent according to claim 5 , wherein X 5 , X 7 , and X 9 are each independently a group represented by —(R 31 ) p′ — (X a ) q′ —

wherein

R 31 each independently represents a single bond, —(CH 2 ) s′ —, wherein s′ is an integer of 1 to 20, or an o-, m- or p-phenylene group;

X a represents —(X b ) l′ —, wherein l′ is an integer of 1 to 10;

X b is each independently at each occurrence a group selected from the group consisting of —O—, —S—, an o-, m- or p-phenylene group, —C(O)O—, —Si(R 33 ) 2 —, —(Si(R 33 ) 2 O) m′ —Si(R 33 ) 2 —, wherein m′ is an integer of 1 to 100, —CONR 34 —, —O—CONR 34 —, —NR 34 — and —(CH 2 ) n′ —, wherein n′ is an integer of 1 to 20;

R 33 is each independently at each occurrence a phenyl group, a C 1-6 alkyl group, or a C 1-6 alkoxy group;

R 34 is each independently at each occurrence a hydrogen atom, a phenyl group, or a C 1-6 alkyl group;

p′ is 0, 1, or 2;

q′ is 0 or 1;

provided that at least one of p′ and q′ is 1, and the occurrence order of the respective repeating units in parentheses provided with p′ or q′ is not limited in the formula; and

R 31 and X a are optionally substituted with one or more substituents selected from a fluorine atom, a C 1-3 alkyl group, and a C 1-3 fluoroalkyl group.

14 . The surface-treating agent according to claim 5 , wherein X 5 , X 7 , and X 9 are each independently:

a single bond, or —Rf′—X 10 —

wherein X 10 is a group selected from the group consisting of:

—CH 2 O(CH 2 ) 2 —,

—CH 2 O(CH 2 ) 3 —,

—CH 2 O(CH 2 ) 6 —,

—CH 2 O(CH 2 ) 3 Si(CH 3 ) 2 OSi(CH 3 ) 2 (CH 2 ) 2 —,

—CH 2 O(CH 2 ) 3 Si(CH 3 ) 2 OSi(CH 3 ) 2 OSi(CH 3 ) 2 (CH 2 ) 2 —,

—CH 2 O(CH 2 ) 3 Si(CH 3 ) 2 O(Si(CH 3 ) 2 O) 2 Si(CH 3 ) 2 (CH 2 ) 2 —,

—CH 2 O(CH 2 ) 3 Si(CH 3 ) 2 O(Si(CH 3 ) 2 O) 3 Si(CH 3 ) 2 (CH 2 ) 2 —,

—CH 2 O(CH 2 ) 3 Si(CH 3 ) 2 O(Si(CH 3 ) 2 O) 10 Si(CH 3 ) 2 (CH 2 ) 2 —,

—CH 2 O(CH 2 ) 3 Si(CH 3 ) 2 O(Si(CH 3 ) 2 O) 20 Si(CH 3 ) 2 (CH 2 ) 2 —,

—CH 2 OCF 2 CHFOCF 2 —,

—CH 2 OCF 2 CHFOCF 2 CF 2 —,

—CH 2 OCF 2 CHFOCF 2 CF 2 CF 2 —,

—CH 2 OCH 2 CF 2 CF 2 OCF 2 —,

—CH 2 OCH 2 CF 2 CF 2 OCF 2 CF 2 —,

—CH 2 OCH 2 CF 2 CF 2 OCF 2 CF 2 CF 2 —,

—CH 2 OCH 2 CF 2 CF 2 OCF(CF 3 ) CF 2 OCF 2 —,

—CH 2 OCH 2 CF 2 CF 2 OCF(CF 3 ) CF 2 OCF 2 CF 2 —,

—CH 2 OCH 2 CF 2 CF 2 OCF(CF 3 ) CF 2 OCF 2 CF 2 CF 2 —,

—CH 2 OCH 2 CHFCF 2 OCF 2 —,

—CH 2 OCH 2 CHFCF 2 OCF 2 CF 2 —,

—CH 2 OCH 2 CHFCF 2 OCF 2 CF 2 CF 2 —,

—CH 2 OCH 2 CHFCF 2 OCF(CF 3 ) CF 2 OCF 2 —,

—CH 2 OCH 2 CHFCF 2 OCF(CF 3 ) CF 2 OCF 2 CF 2 —,

—CH 2 OCH 2 CHFCF 2 OCF(CF 3 ) CF 2 OCF 2 CF 2 CF 2 —,

—CH 2 OCH 2 (CH 2 ) 7 CH 2 Si(OCH 3 ) 2 OSi(OCH 3 ) 2 (CH 2 ) 2 Si(OCH 3 ) 2 OSi(OCH 3 ) 2 (CH 2 ) 2 —,

—CH 2 OCH 2 CH 2 CH 2 Si(OCH 3 ) 2 OSi(OCH 3 ) 2 (CH 2 ) 3 —,

—CH 2 OCH 2 CH 2 CH 2 Si(OCH 2 CH 3 ) 2 OSi(OCH 2 CH 3 ) 2 (CH 2 ) 3 —,

—CH 2 OCH 2 CH 2 CH 2 Si(OCH 3 ) 2 OSi(OCH 3 ) 2 (CH 2 ) 2 —,

—CH 2 OCH 2 CH 2 CH 2 Si(OCH 2 CH 3 ) 2 OSi(OCH 2 CH 3 ) 2 (CH 2 ) 2 —,

—(CH 2 ) 2 —,

—(CH 2 ) 3 —,

—(CH 2 ) 4 —,

—(CH 2 ) 5 —,

—(CH 2 ) 6 —,

—(CH 2 ) 2 —Si(CH 3 ) 2 —(CH 2 ) 2 —,

—CONH—(CH 2 )—,

—CONH—(CH 2 ) 2 —,

—CONH—(CH 2 ) 3 —,

—CON(CH 3 )—(CH 2 ) 3 —,

—CON(Ph)-(CH 2 ) 3 —, wherein Ph means phenyl,

—CONH—(CH 2 ) 6 —,

—CON(CH 3 )—(CH 2 ) 6 —,

—CON(Ph) —(CH 2 ) 6 —, wherein Ph means phenyl,

—CONH—(CH 2 ) 2 NH(CH 2 ) 3 —,

—CONH—(CH 2 ) 6 NH(CH 2 ) 3 —,

—CH 2 O—CONH—(CH 2 ) 3 —,

—CH 2 O—CONH—(CH 2 ) 6 —,

—S—(CH 2 ) 3 —,

—(CH 2 ) 2 S(CH 2 ) 3 —,

—CONH—(CH 2 ) 3 Si(CH 3 ) 2 OSi(CH 3 ) 2 (CH 2 ) 2 —,

—CONH—(CH 2 ) 3 Si(CH 3 ) 2 OSi(CH 3 ) 2 OSi(CH 3 ) 2 (CH 2 ) 2 —,

—CONH—(CH 2 ) 3 Si(CH 3 ) 2 O(Si(CH 3 ) 20 ) 2 Si(CH 3 ) 2 (CH 2 ) 2 —,

—CONH—(CH 2 ) 3 Si(CH 3 ) 2 O(Si(CH 3 ) 2 O) 3 Si(CH 3 ) 2 (CH 2 ) 2 —,

—CONH—(CH 2 ) 3 Si(CH 3 ) 2 O(Si(CH 3 ) 2 O) 10 Si(CH 3 ) 2 (CH 2 ) 2 —,

—CONH—(CH 2 ) 3 Si(CH 3 ) 2 O(Si(CH 3 ) 2 O) 2 OSi(CH 3 ) 2 (CH 2 ) 2 —,

—C(O)O—(CH 2 ) 3 —,

—C(O)O—(CH 2 ) 6 —,

—CH 2 —O—(CH 2 ) 3 —Si(CH 3 ) 2 —(CH 2 ) 2 —Si(CH 3 ) 2 —(CH 2 ) 2 —,

—CH 2 —O—(CH 2 ) 3 —Si(CH 3 ) 2 —(CH 2 ) 2 —Si(CH 3 ) 2 —CH(CH 3 )—,

—CH 2 —O—(CH 2 ) 3 —Si(CH 3 ) 2 —(CH 2 ) 2 —Si(CH 3 ) 2 —(CH 2 ) 3 —,

—CH 2 —O—(CH 2 ) 3 —Si(CH 3 ) 2 —(CH 2 ) 2 —Si(CH 3 ) 2 —CH(CH 3 )—CH 2 —,

—OCH 2 —,

—O(CH 2 ) 3 —,

—OCFHCF 2 —,

 Rf′ is a single bond or —(C l′ F 2l′ )—; and

 l′ is an integer of 1 to 4.

15 . The surface-treating agent according to claim 5 , wherein X 5 , X 7 , and X 9 are each independently a tri- to decavalent organic group.

16 . The surface-treating agent according to claim 15 , wherein X 5 , X 7 , and X 9 are each independently selected from the group consisting of:

wherein in each group, at least one T is the following group bonded to PFPE in the formulae (A1), (A2), (B1), (B2), (C1) and (C 2 ):

—Rf′—X 11 —

wherein X 11 is a group selected from the group consisting of

—CH 2 O(CH 2 ) 2 —,

—CH 2 O(CH 2 ) 3 —,

—CF 2 O(CH 2 ) 3 —,

—(CH 2 ) 2 —,

—(CH 2 ) 3 —,

—(CH 2 ) 4 —,

—CONH—(CH 2 )—,

—CONH—(CH 2 ) 2 —,

—CONH—(CH 2 ) 3 —,

—CON(CH 3 )—(CH 2 ) 3 —,

—CON(Ph)-(CH 2 ) 3 —, wherein Ph means phenyl, and

 Rf′ is a single bond or —(C l′ F 2l′ )—; and

 l′ is an integer of 1 to 4;

 at least one other T is —(CH 2 ) n —, wherein n is an integer of 2 to 6, bonded to a carbon atom or a Si atom in the formulae (A1), (A2), (B1), (B2), (C1) and (C2), and the other T, when present, are each independently a methyl group, a phenyl group, an alkoxy group having 1 to 6 carbon atoms, or a radical scavenging group or a UV absorbing group,

 R 41 is each independently a hydrogen atom, a phenyl group, an alkoxy group having 1 to 6 carbon atoms, or an alkyl group having 1 to 6 carbon atoms, and

 R 42 each independently represents a hydrogen atom, a C 1-6 alkyl group, or a C 1-6 alkoxy group.

17 . The surface-treating agent according to claim 1 , wherein the number average molecular weight of the fluoroalkylsilane oligomer mixture is 300 or more.

18 . The surface-treating agent according to claim 1 , wherein the number average molecular weight of the fluoroalkylsilane oligomer mixture is 4,500 or less.

19 . The surface-treating agent according to claim 1 , wherein the content of the fluoroalkylsilane oligomer mixture is 20% by mass or less based on the total amount of the fluoroalkylsilane oligomer mixture and the perfluoroalkyl group-containing silane compound.

20 . The surface-treating agent according to claim 1 , wherein the content of the fluoroalkylsilane oligomer mixture is 0.1% by mass or more based on the total amount of the fluoroalkylsilane oligomer mixture and the perfluoroalkyl group-containing silane compound.

21 . An article comprising a substrate and a layer on a surface of the substrate, the layer being formed of the surface-treating agent according to claim 1 .

22 . The article according to claim 21 , which is an optical member.