P 03  represents ----C(=O)-O- or -C(=O)-NRn› (wherein  Rn  represents a hydrogen atom or an alkyl group of $^{30 }$ 1  to 5 carbon atoms), and is preferably----C(=O)-O-. The  alkyl group for  Rn  is the same as defined above for the alkyl  group for R.  35  [Chemical Formula 43]  [Structural Unit Represented by General Formula (a3-13)]  In the above formula (a3-13), R is the same as defined  above for R in formula (a3-l).  The linear hydrocarbon group for W$^{03 }$preferably contains  1  to  10  carbon atoms, more preferably  1  to 5 carbon atoms,  and still more preferably  1  to 3 carbon atoms.  The linear hydrocarbon group for W$^{03 }$may also have a  substituent (a) other than the -OH, -COOR, ----CN,  -SO$_{2}$NH$_{2 }$ and/or ----CONH$_{2 }$ substituent. Examples of this  substituent (a) include an alkyl group of  1  to 5 carbon atoms,  an aliphatic cyclic group (monocyclic group or polycyclic  group), a fluorine atom, and a fluorinated alkyl group of  1  to  5 carbon atoms. The aliphatic cyclic group (monocyclic  group or polycyclic group) for the substituent (a) preferably  contains 3 to 30 carbon atoms, more preferably 5 to 30 carbon  atoms, still more preferably 5 to 20 carbon atoms, still more  preferably 6 to 15 carbon atoms, and most preferably 6 to 12  carbon atoms. Examples include groups in which one or more  hydrogen atoms have been removed from a monocycloal› kane, and groups in which one or more hydrogen atoms have  been removed from a polycycloalkane such as a bicycloal- kane, tricycloalkane or tetracycloalkane. Specific 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 polycycloal- kane such as adamantane, norbomane, isobomane, tricyclo› decane or tetracyclododecane.  Further, the linear hydrocarbon group for W$^{03 }$may have a  plurality of the substituents (a), as shown below for a struc› tural unit represented by general formula (a3-13-a), and this  plurality of the substituents (a) may be bonded to each other  to form a ring.  [Chemical Formula 44]  q $^{0 }$is preferably  1  or 2, and is more preferably  1.  Further, R  al  and R  a $^{2 }$may be bonded to each other to form  a ring. In this case, a cyclic group is formed from R  al,  R  a 2 ,  and  the carbon atom to which both Ra $^{1 }$and  Ra $^{2 }$are bonded. The  thus formed cyclic group may be a monocyclic group or a  polycyclic group, and specific examples include groups in  which one or more hydrogen atoms have been removed from  the types of monocycloalkanes and polycycloalkanes men› tioned above within the description of the aliphatic cyclic  group (monocyclic group or polycyclic group) for the afore- mentioned substituent (a).  The aliphatic cyclic group (monocyclic group or polycy› clic group) for Ra $^{1 }$and  Ra $^{2 }$is the same as the aliphatic cyclic  group (monocyclic group or polycyclic group) described  above for the substituent (a).  In formula (a3-13-a), R is the same as defined above for R  in formula (a3-l).  In the formula, R represents a hydrogen atom, an alkyl group  of  1  to 5 carbon atoms or a halogenated alkyl group of  1  to 5  carbon atoms, and each ofRa$^{1 }$and  Ra $^{2 }$independently repre› sents an alkyl group of  1  to 5 carbon atoms, an aliphatic cyclic  group (monocyclic group or polycyclic group), a fluorine  atom or a fluorinated alkyl group of  1  to 5 carbon atoms.  Further, Ra$^{1 }$and  Ra $^{2 }$may be bonded to each other to form a  ring. q $^{0 }$represents an integer of  1  to  4.  -continued  US 9,164,380 B2  98  97  Specific examples of preferred structural units represented  by general formula (a3-13) are shown below. In each of the  following formulas, R"’ represents a hydrogen atom, a methy  1  group, or a trifluoromethyl group.  (a3-13-1)  (a3-12-17)  (a3-12-16)  (a3-13-a) 