As examples of A", the same groups as those described  above for A’ in general formula (3-1) can be given. A" is  preferably an alkylene group of 1 to 5 carbon atoms, an  oxygen atom  (-0-)  or a sulfur atom (-S-), and more  preferably an alkylene group ofl to 5 carbon atoms or---0-. 20  As the alkylene group of 1 to 5 carbon atoms, a methylene  group or a dimethylethylene group is preferable, and a meth› ylene group is particularly desirable.  R $^{29 }$is the same as defined for R$^{29 }$in the aforementioned  general formula (a2-0).  In formula (a2-1), s" is preferably 1 or 2.  Specific examples of structural units represented by gen› eral formulas (a2-1) to (a2-5) are shown below. In the formu- las shown below, R"’ represents a hydrogen atom, a methyl 30  group or a trifluoromethyl group.  [Chemical Formula 33]  When R" is a cyclic alkyl group ( cycloalkyl group), it  preferably has 3 to 15 carbon atoms, more preferably 4 to 12  carbon atoms, and most preferably 5 to 10 carbon atoms. As  examples of the cycloalkyl group, groups in which one or  more hydrogen atoms have been removed from a monocy- cloalkane or a polycycloalkane such as a bicycloalkane, tri› cycloalkane or tetracycloalkane, which may or may not be  substituted with a fluorine atom or a fluorinated alkyl group,  may be used. Examples of such groups include groups in  which one or more hydrogen atoms have been removed from  a monocycloalkane such as cyclopentane or cyclohexane; and  groups in which one or more hydrogen atoms have been  removed from a polycycloalkane such as adamantane, nor› bomane, isobornane, tricyclodecane or tetracyclododecane.  -continued  US 9,063,416 B2  75  76  (a2-1-1)  (a2-1-2)  (a2-1-3)  Ra  ~!r  04  0  (a2-1-8)  Ra  ~co/  04  0  (a2-1-7)  Ra  ~/y  04  0  (a2-1-6)  Ra  /"6Y  04  0  (a2-1-5)  Ra  ~/,Y  04  (a2-1-4) 