Q represents an alkyl group, a cycloalkyl group, an alicy- clic group which may contain a hetero atom, an aromatic  ring group which may contain a hetero atom, an amino  group, an ammonium group, a mercapto group, a cyano  group or an aldehyde group;  the group represented by -M-Q is a group constituted of  from 5 to 20 carbon atoms; and  at least two ofQ, M andL$_{1 }$maybe bonded to each other to  form a 5-membered ring or a 6-membered ring;  further provided that the repeating unit represented by the  general formula  (I)  is selected from the group consisting  of the following repeating units:  184  US 9,217,919 B2  183  and  -continued  the repeating unit represented by general formula (III-1) is  selected from the group consisting of the following  repeating units:  oyo~ 0  oyo~ 0  s~e •s-fO)  3  •+mQ•  s~e  OH  •+mQ•  S03G  ~  H3C  ~  ,,()  oyo~ 0  ~  I  oyo~ 0  oyo~o  ~:  I  ~I  oyo~ 0 