Antifouling article

1. An antifouling article comprising a base material, a diamond-like carbon layer and an antifouling coating layer formed of a surface-treating agent on the diamond-like carbon layer, wherein

the surface-treating agent comprises one or more fluorine-containing compounds represented by any of the following formulas (A1), (A2), (B1) and (B2):

(Rf-PFPE) α′ -X 1 —(Y-A) α   (A1)

(A-Y) α —X 1 -PFPE-X 1 —(Y-A) α   (A2)

(R 91 —Rf) β′ —X 2 —(Y-A) β   (B1)

(A-Y) β -X 2 -Rf-X 2 -(Y-A) β   (B2)

wherein

A represents, each independently at each occurrence, a cyano group, an oxime derivative group, a nitro group, a trimethylsilyl group, a titanium alkoxide group, a titanium acylate group, a functional group containing a transition metal, a bromine atom, an iodine atom, a methyl sulfate ion, a methanesulfonate ion, a trifluoromethanesulfonate ion, or a 4-methylbenzenesulfonate ion;

when A is a bromine atom or an iodine atom, A is directly bonded to a carbon atom;

Y represents, each independently at each occurrence, a single bond or a divalent organic group;

Rf represents, each independently, an alkyl group having 1 to 16 carbon atoms and optionally substituted by one or more fluorine atoms;

PFPE represents, each independently, —(OC 6 F 12 ) a —(OC 5 F 10 ) b —(OC 4 F 8 ) c —(OC 3 F 6 ) d —(OC 2 F 4 ) e —(OCF 2 ) f —, wherein a, b, c, d, e and f are each independently an integer of not less than 0 and not more than 200, the sum of a, b, c, d, e and f is at least 1, and the order of presence of each repeating unit enclosed in parentheses and affixed with a, b, c, d, e or f is arbitrary in the formula;

X 1 represents, each independently, a single bond or a 2-10 valent organic group;

α is each independently at each occurrence, an integer of 1 to 9;

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

X 2 represents, each independently at each occurrence, a single bond or a 2-10 valent organic group;

β is each independently at each occurrence an integer of 1 to 9;

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

R 91 represents a fluorine atom, —CHF 2 or —CF 3 ; and

Rf′ represents, each independently at each occurrence, a perfluoroalkylene group having 1 to 20 carbon atoms.

2. The antifouling article according to claim 1 , wherein A is present at an end part of a molecular chain of the fluorine-containing compound.

3. The antifouling article according to claim 1 , wherein Rf is a perfluoroalkyl group having 1 to 16 carbon atoms.

4. The antifouling article according to claim 1 , wherein PFPE is independently at each occurrence the following formula (a), (b) or (c):

—(OC 3 F 6 ) d —  (a)

wherein d is an integer of 1 to 200,

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

wherein c and d are each independently an integer of not less than 0 and not more than 30;

e and f are each independently an integer of not less than 1 and not more than 200;

the sum of c, d, e and f is an integer of not less than 10 and not more than 200; and

the order of presence of each repeating unit enclosed in parentheses and affixed with a subscript c, d, e or f is arbitrary in the formula,

—(R 6 —R 7 ) j —  (c)

wherein R 6 is OCF 2 or OC 2 F 4 ;

R 7 is a group selected from OC 2 F 4 , OC 3 F 6 , OC 4 F 8 , OC 5 F 10 and OC 6 F 12 , or a combination of 2 or 3 groups selected from these groups; and

j is an integer of 2 to 100.

5. The antifouling article according to claim 1 , wherein X 1 and X 2 are each independently a divalent organic group, α and β are each 1, and α′ and β′ are each 1.

6. The antifouling article according to claim 1 , wherein X 1 and X 2 are each independently a group represented by —(R 31 ) p′ —(X a ) q′ —

wherein

R 31 represents a single bond, —(CH 2 ) s′ — or an o-, m- or p-phenylene group;

s′ is an integer of 1 to 20;

X a represents —(X b ) l′ —;

X b represents, 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 —, —CONR 34 —, —O—CONR 34 —, —NR 34 — and —(CH 2 ) n′ —;

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

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

m′ is, each independently at each occurrence, an integer of 1 to 100;

n′ is, each independently at each occurrence, an integer of 1 to 20;

l′ is an integer of 1 to 10;

p′ is 0 or 1;

q′ is 0 or 1; and

at least one of p′ and q′ is 1, and the order of presence of each repeating unit enclosed in parentheses and affixed with p′ or q′ is arbitrary.

7. The antifouling article according to claim 1 , wherein R 91 is a fluorine atom or CF 3 .

8. The antifouling article according to claim 1 , wherein the fluorine-containing compound is at least one compound represented by either formula (A1) or (A2).

9. The antifouling article according to claim 1 , wherein the fluorine-containing compound is at least one compound represented by either formula (B1) or (B2).

10. The antifouling article according to claim 1 , wherein the surface-treating agent further comprises one or more other components selected from a fluorine-containing oil, a silicone oil and a catalyst.

11. The antifouling article according to claim 10 , wherein the fluorine-containing oil is one or more compounds represented by formula (3):

Rf 5 —(OC 4 F 8 ) a′ —(OC 3 F 6 ) b′ —(OC 2 F 4 ) c′ —(OCF 2 ) d′ —Rf 6 —  (3)

wherein

Rf 5 represents an alkyl group having 1 to 16 carbon atoms and optionally substituted by one or more fluorine atoms;

Rf 6 represents an alkyl group having 1 to 16 carbon atoms and optionally substituted by one or more fluorine atoms, a fluorine atom or a hydrogen atom; and

a′, b′, c′ and d′ each represent the number of repeating units of each type among 4 types of perfluoro(poly)ether constituting a main backbone of a polymer and are each independently an integer of not less than 0 and not more than 300, the sum of a′, b′, c′ and d′ is at least 1, and the order of presence of each repeating unit enclosed in parentheses and affixed with a subscript a′, b′, c′ or d′ is arbitrary in the formula.

12. The antifouling article according to claim 10 , wherein the fluorine-containing oil is one or more compounds represented by formula (3a) or (3b):

Rf 5 —(OCF 2 CF 2 CF 2 ) b″ —Rf 6   (3a)

Rf 5 —(OCF 2 CF 2 CF 2 CF 2 ) a″ —(OCF 2 CF 2 CF 2 ) b″ —(OCF 2 CF 2 ) c″ —(OCF 2 ) d″ —Rf 6   (3b)

wherein

Rf 5 represents an alkyl group having 1 to 16 carbon atoms and optionally substituted by one or more fluorine atoms;

Rf 6 represents an alkyl group having 1 to 16 carbon atoms and optionally substituted by one or more fluorine atoms, a fluorine atom or a hydrogen atom;

in formula (3a), b″ is an integer of not less than 1 and not more than 100;

in formula (3b), a″ and b″ are each independently an integer of not less than 0 and not more than 30, and c″ and d″ are each independently an integer of not less than 1 and not more than 300; and

the order of presence of each repeating unit enclosed in parentheses and affixed with a subscript a″, b″, c″ or d″ is arbitrary in the formula.

13. The antifouling article according to claim 1 , wherein the base material is glass or sapphire glass.

14. The antifouling article according to claim 13 , wherein the glass is selected from the group consisting of soda-lime glass, alkali aluminosilicate glass, borosilicate glass, alkali-free glass, crystal glass and quartz glass.

15. The antifouling article according to claim 1 , wherein the article is an optical member.

16. The antifouling article according to claim 1 , wherein A is a cyano group, an oxime derivative group, or a nitro group.

17. The antifouling article according to claim 1 , wherein A is a trimethylsilyl group, a titanium alkoxide group, a titanium acylate group, or a functional group containing a transition metal.

18. The antifouling article according to claim 1 , wherein A is a bromine atom or an iodine atom.

19. The antifouling article according to claim 1 , wherein A is a methyl sulfate ion, a methanesulfonate ion, a trifluoromethanesulfonate ion, or a 4-methylbenzenesulfonate ion.