211  US 9,411,230 B2  212  R$_{2 }$ are preferably a methylene group, an ethylene group, an  n-propylene group, an isopropylene group, an n-butylene  group, an isobutylene group or a sec-butylene group.  In the case where R$_{1 }$and/or R$_{2 }$are an alicyclic hydrocarbon  group, the alicyclic hydrocarbon group may be monocyclic or 5  polycyclic. The alicylcic hydrocarbon group has, for  example, a monocyclo, bicyclo, tricyclo or tetracyclo struc› ture. The carbon number of the alicyclic hydrocarbon group is  usually 5 or more, preferably from 6 to 30, more preferably  from 7 to 25.  The alicyclic hydrocarbon group includes, for example,  those having a partial structure illustrated below. Each of  these partial structures may have a substituent. Also, in each  of these partial structures, the methylene group (----CH$_{2}$ $^{-) }$15  may be substituted with an oxygen atom  (-0-),  a sulfur  atom (-S-), a carbonyl group [----C(=O)-], a sulfonyl  group [-S(=0)$_{2}$ -],  a sulfinyl group [-S(=O)-] or an  imino group [-N(R)-] (wherein Risa hydrogen atom or an  alkyl group).  For example, when R$_{1 }$and/or R$_{2 }$are a cycloalkylene group,  R$_{1 }$and/or R$_{2 }$are preferably an adamantylene group, a norada- l> □ OOO  OLJW  coo=>co  CCDQ:o  o9  cB  O:OCCX>  C)>CXJ  00 00  Q<J  CD CCO  er'  CC □  CD> '  ~  6)6JOJQ)  Q]GDCQ  -continued 