143  US 9,323,150 B2  144  -continued  -continued  In some aspects, it is preferred for the repeating units of  general formula (A2) to be those oft-butyl methacrylate and  ethylcyclopentyl methacrylate.  The monomers corresponding to the repeating units of  general formula (A2) can be synthesized by performing an  esterification between (meth)acrylic chloride and an alcohol  compound in a solvent, such as THF, acetone or methylene  chloride, in the presence of a basic catalyst, such as triethy› lamine, pyridine or DBU. Alternatively, commercially avail› able monomers may be used.  The resin (Ab) may further comprise any of repeating units  of general formula (A5) below.  In formula (A5),  X represents a hydrogen atom, an alkyl group, a hydroxyl  group, an alkoxy group, a halogen atom, a cyano group, a  nitro group, an acyl group, an acyloxy group, a cycloalkyl  group, an aryl group, a carboxyl group, an alkyloxycarbonyl  group, an alkylcarbonyloxy group or an aralkyl group, being  similar to X of general formula (A2b ).  A$_{4 }$ represents a hydrocarbon group not cleaved under the  action of an acid.  As the hydrocarbon group not cleaved under the action of  an acid, represented by A$_{4 }$ in general formula (A5), there can  be mentioned any of hydrocarbon groups other than the above  acid-decomposable groups, for example, an alkyl group  (preferably 1 to 15 carbon atoms) not cleaved under the action  of an acid, a cycloalkyl group (preferably 31 to 15 carbon  atoms) not cleaved under the action of an acid, an aryl group  (preferably 6 to 15 carbon atoms) not cleaved under the action  of an acid and the like.  The hydrocarbon group not cleaved under the action of an  acid, represented by A$_{4 }$ may further be substituted with a  hydroxyl group, an alkyl group, a cycloalkyl group, an aryl  group or the like.  It is also preferred for the resin (Ab) to further comprise  any of repeating units of general formula (A6) below.  In general formula (A6),  R$_{2 }$ represents a hydrogen atom, a methyl group, a cyano  group, a halogen atom or a perfluoro group having 1 to 4  carbon atoms.  CH3  I  ----f-CH2-C-t- OAO  ----f-CH2 -CH  --t- OAO  (A5)  (A6) 