Silsesquioxane
A silsesquioxane compound represented by the following formula (I): (R a SiO 1.5 ) n , wherein R a is, each independently at each occurrence, R b or R c ; provided that at least one R a is R b ; R b is —R 1 —CF 2 —R 2 —R 3 ; R 1 is a divalent group; R 2 is a divalent polymer chain; R 3 is a halogen atom or a hydrogen atom; R c is a hydrogen atom, an alkyl group, a phenyl group, or —(OSiR 15 2 ) j —R 15 ; R 15 is, each independently at each occurrence, a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; j is, each independently at each occurrence, an integer of 1 to 3; and n is an arbitrary integer.
1. A silsesquioxane compound represented by the following formula (I):
(R a SiO 1.5 ) n
wherein
R a is, each independently at each occurrence, R b or R c ;
provided that at least one R a is R b ;
R b is —R 1 —CF 2 —R 2 —R 3 ;
R 1 is —(CF 2 ) s1 —or —(CF 2 ) t1 O(CF 2 ) t2— ;
s1 is an integer of 2 to 10;
t1 and t2 are each independently an integer of 2 to 6;
R 2 is a divalent polymer chain;
R 3 is a halogen atom or a hydrogen atom;
R c is a hydrogen atom, an alkyl group, a phenyl group, or —(OSiR 15 2 ) j— R 15 ;
R 15 is, each independently at each occurrence, a hydrogen atom or an alkyl group having 1 to 6 carbon atoms;
j is, each independently at each occurrence, an integer of 1 to 3; and
n is an integer of 4 or more.
2. The silsesquioxane compound according to claim 1 , wherein R 3 is bromine or iodine.
3. The silsesquioxane compound according to claim 1 , wherein the divalent polymer chain in R 2 is a divalent fluorine-containing polymer chain.
4. The silsesquioxane compound according to claim 1 , wherein the divalent polymer chain in R 2 is composed of a monomer unit derived from monofluoroethylene, 1,1-difluoroethylene, 1,3-difluoroethylene, trifluoroethylene, tetrafluoroethylene, 1,1,1,2-tetrafluoro-2-propylene, hexafluoropropylene, perfluoro(alkylvinyl ether), chlorotrifluoroethylene, vinylidene fluoride, (meth)acrylic acid, (meth)acrylic acid ester, styrene, vinyl acetate, vinyl chloride, vinylidene chloride, or 1,3-butadiene.