209  US 9,411,230 B2  210  The repeating unit (R3) is preferably represented by at least  one formula selected from the group consisting of the follow› ing formulae (I-1) to (I-10). This repeating unit is more pref› erably represented by at least one formula selected from the  group consisting of the following formulae (I-1) to (I-3), still  more preferably represented by the following formula (I-1).  In the formulae, each Ra independently represents a hydro› gen atom, an alkyl group or a group represented by ----CH 2 - O-Ra2, wherein Ra 2  represents a hydrogen atom, an alkyl  group or an acyl group.  R$_{1 }$ represents a (n+l)-valent organic group.  R 2  represents, whenm2:2, each independently represents, a  single bond or a (n+ 1 )-valent organic group.  Each  OP independently represents the above-described  group capable of decomposing by the action of an acid to  produce an alcoholic hydroxy group, and when n2:2 and/or  m2:2, two or more OP’ s may combine with each other to form  a ring.  W represents a methylene group, an oxygen atom or a  sulfur atom,  n and m represent an integer of 1 or more. Incidentally, in  the case where R 2  in formula (I-2), (I-3) or (I-8) represents a  single bond, n is 1.  1 represents an integer of 0 or more.  L$_{1 }$ represents a linking group represented by --COO-,  ---OCO-, -CONH-,  ---0-,  -Ar-,  -SO$_{3}$ - or  -SO 2 NH-,  wherein  Ar  represents a divalent aromatic ring  group.  Each R independently represents a hydrogen atom or an  alkyl group.  R$_{0 }$ represents a hydrogen atom or an organic group.  L$_{3 }$ represents a (m+2)-valent linking group.  RL  represents, whenm2:2, each independently represents, a  (n+l)-valent linking group.  Rs represents, when p2:2, each independently represents, a  substituent, and when p2:2, the plurality of Rss may combine  with each other to form a ring.  p represents an integer of0 to 3.  Ra represents a hydrogen atom, an alkyl group or a group  represented by ----CH 2 ---0-Ra 2 . Ra is preferably a hydro- gen atom or an alkyl group having a carbon number ofl to 10,  more preferably a hydrogen atom or a methyl group.  W  represents a methylene group, an oxygen atom or a  sulfur atom.Wis preferably a methylene group or an oxygen  atom.  R$_{1 }$ represents a (n+l)-valent organic group. R$_{1 }$ is prefer› ably a non-aromatic hydrocarbon group. In this case, R$_{1 }$may  be a chain hydrocarbon group or an alicyclic hydrocarbon  group. R$_{1 }$is more preferably an alicyclic hydrocarbon group.  R 2  represents a single bond or a (n+l)-valent organic  group. R 2  is preferably a single bond or a non-aromatic hydro› carbon group. In this case, R 2  may be a chain hydrocarbon  group or an alicyclic hydrocarbon group.  In the case where R$_{1 }$ and/or R 2  are a chain hydrocarbon  group, the chain hydrocarbon group may be a linear or  branched-chain hydrocarbon group. The carbon number of  the chain hydrocarbon group is preferably from 1 to 8. For  example, when R$_{1 }$and/or R 2  are an alkylene group, R$_{1 }$and/or  Ra  Ra  (1-2)  (1-3)  (1-5)  ky  OP  (1-6)  YY1’  o......._ _,,..o  p  (1-9)  (1-10)  -continued 