US 8,298,748 B2  114  113  -continued  R 4 "  represents an alkyl group, a halogenated alkyl group,  an aryl group or an alkenyl group which may have a substitu› ent.  The alkyl group for R 4 "  may be any oflinear, branched or  cyclic.  The linear or branched alkyl group preferably has 1 to 10  carbon atoms, more preferably 1 to 8 carbon atoms, and most  preferably 1 to 4 carbon atoms.  The cyclic alkyl group preferably has 4 to 15 carbon atoms,  more preferably 4 to 10 carbon atoms, and most preferably 6  to 10 carbon atoms.  As an example of the halogenated alkyl group for R 4 ",  a  group in which part of or all of the hydrogen atoms of the  aforementioned linear, branched or cyclic alkyl group have  been substituted with halogen atoms can be given. Examples  of the aforementioned halogen atom include a fluorine atom,  a chlorine atom, a bromine atom and an iodine atom, and a  fluorine atom is preferable.  In the halogenated alkyl group, the percentage of the num› ber of halogen atoms based on the total number of halogen  atoms and hydrogen atoms (halogenation ratio(%)) is pref› erably 10 to 100%, more preferably 50 to 100%, and most  preferably 100%. Higher halogenation ratio is preferable  because the acid strength increases.  The aryl group for R 4 "  is preferably an aryl group of 6 to 20  carbon atoms.  The alkenyl group for R 4 "  is preferably an alkenyl group of  2 to 10 carbon atoms.  With respect to R 4 ",  the expression "may have a substitu› ent" means that part of or all of the hydrogen atoms within the  aforementioned linear, branched or cyclic alkyl group, halo- The cyclic group may be either an aromatic hydrocarbon  group which may have a substituent, or an aliphatic cyclic  group which may have a substituent, and an aliphatic cyclic  group which may have a substituent is preferable.  In the present invention, as X 00 , a cyclic group which may  have a substituent is preferable.  In the group represented by the formula X$^{00}$-Q 8 -,  the  hydrocarbon group for X$^{00 }$is the same as defined for X 0  in  formula (1) explained above in relation to the structural unit  (a0-2).  Q 1  is preferably a divalent linking group containing an  ester linkage or ether linkage, and more preferably a group of  -R 91 -O-, -R $^{92}$---0-C(=O)- or -C(=O)-O› R93 ---0-C(=O)-.  Specific examples of alkylene groups include a methylene  group [----CH$_{2}$ -];  alkylmethylene groups such as -CH  (CH 3 )-, -CH(CH$_{2}$CH 3 )-, ----C(CH 3 )$_{2}$-, -C(CH 3 )  (CH$_{2}$CH 3 )-,  -C(CH 3 )(CH$_{2}$CH$_{2}$CH 3 )- and  ----C(CH$_{2}$CH 3 )$_{2}$-; an ethylene group [----CH$_{2}$CH$_{2}$-]; alky- $^{!ethylene groups such as ----CH(CH}$3)CH$_{2}$ -,  -CH(CH 3 )CH  (CH 3 )-, ----C(CH 3 )$_{2}$CH$_{2}$ - and ----CH(CH$_{2}$CH 3 )CH$_{2}$-; a  trimethylene  group  (n-propylene  group)  [-CH$_{2}$CH$_{2}$CH$_{2}$-]; alkyltrimethylene groups such as -CH  (CH 3 )CH$_{2}$CH$_{2}$ - and ----CH$_{2}$CH(CH 3 )CH$_{2}$-; a tetrameth- ylene group [----CH$_{2}$CH$_{2}$CH$_{2}$CH$_{2}$-]; alkyltetramethylene  groups such as ----CH(CH 3 )CH$_{2}$CH$_{2}$CH$_{2}$ - and -CH$_{2}$CH  (CH 3 )CH$_{2}$CH$_{2}$-;  and  a  pentamethylene  group  [-CH$_{2}$CH$_{2}$CH$_{2}$CH$_{2}$CH$_{2}$-].  The alkylene group for R 91  to R 93  is preferably a linear or  branched alkylene group, and preferably has 1 to 12 carbon  atoms, more preferably 1 to 5, and most preferably 1 to 3.  Specific examples of the combinations of the aforemen› tioned non-hydrocarbon, hetero atom-containing linking  groups and an alkylene group include -R 91 ---0-, -R 92  - O----C(=O)-, -C(=O)-O-R 93 -O----C(=O)- (in the  formulas, each of R 91  to R 93  independently represents an  alkylene group).  Examples of divalent linking groups containing an oxygen  atom include non-hydrocarbon, oxygen atom-containing  linking groups such as an oxygen atom ( an ether bond;  ---0-), an ester bond (-C(=O)---0-), an amido bond  (-C(=O)-NH-), a carbonyl group (-C(=O)-) and a  carbonate bond (--0-C(=O)---0-); and combinations of  the aforementioned non-hydrocarbon, hetero atom-contain› ing linking groups with an alkylene group.  Q 8  may contain an atom other than an oxygen atom.  Examples of atoms other than oxygen include a carbon atom,  a hydrogen atom, a sulfur atom and a nitrogen atom.  Examples ofhetero atoms include an oxygen atom, a nitro› gen atom, and a sulfur atom.  Examples of halogen atoms and alkyl groups as substitu› ents for R 4 "  include the same halogen atoms and alkyl groups  as those described above with respect to the halogenated alkyl  group for R 4 ".  R 4 "  may have one substituent, or two or more substituents.  Examples of the substituent include a halogen atom, a  hetero atom, an alkyl group, and a group represented by the  formula  x $^{00 }$-Q8  - (in the formula, Q 8  represents a divalent  linking group containing an oxygen atom; and X$^{00 }$represents  a hydrocarbon group of3 to 30 carbon atoms which may have  a substituent).  genated alkyl group, aryl group or alkenyl group may be  substituted with substituents (atoms other than hydrogen  atoms, or groups).  In the group represented by formula x$^{00}$-Q 8 -, Q 8  repre› sents a divalent linking group containing an oxygen atom.  (1-1-7)  (1-1-8)  (1-1-9) 