US 10,005,868 B2  48  47  -continued  -continued  '-)  (A-3)-6  (A-3)-7  RL43  R=)  (A-3)-8  r)  (A-3)-9  (A-3)-10  Wj)  (A-3)-11  (A-3)-12  (A-3)-13  In the formulae (A-3)-1 to (A-3)-18, each  RL $^{43 }$may be the  same or different, and represents a linear, branched, or cyclic  alkyl group having 1 to 8 carbon atoms, or an aryl group  having 6 to 20 carbon atoms, such as a phenyl group and a  naphthyl group.  RL $^{44 }$and  RL $^{46 }$represent a hydrogen atom or  a linear, branched, or cyclic alkyl group having 1 to 20  carbon atoms.  RL $^{45 }$represents an aryl group having 6 to 20  carbon atoms, such as a phenyl group.  Furthermore, as shown in the following formulae (A-3)- 19 and (A-3)-20, the polymer may contain  RL 47  which  represents a group with two or more valency such as an  alkylene group and an arylene group to form intermolecular  or intramolecular crosslinking.  (A-3)-14  (A-3)-15  (A-3)-16  (A-3)-17  (A-3)-18 