A polymer including a block chain A which is formed from a random copolymer containing a repeating unit (I) represented by the formula (I) wherein R1 to R3 each independently represents hydrogen or C1-10 hydrocarbon and R1 and R3 may bond to form a ring; R4a and R4b each independently represents hydrogen or methyl; R5 represents hydrogen, hydrocarbon, acyl, or silyl; and m represents any integer of 1 to 100 and when m is 2 or more and each R4a may be the same or different from one another and each R4b may be the same or different from one another; and a repeating unit (II) represented by the formula (II) wherein R6 and R8 each independently represents hydrogen or C1-10 hydrocarbon and R6 and R8 may bond to form a ring; R7 represents hydrogen, C1-10 hydrocarbon, hydroxyl, hydrocarbonoxy, carboxyl, acid anhydride, amino, ester, or an organic group having at least one functional group selected from the group consisting of hydroxyl, carboxyl, epoxy, acid anhydride, and amino; and R9 represents an organic group having at least one functional group selected from the group consisting of hydroxyl, carboxyl, epoxy, acid anhydride, and amino; and a block chain B having a repeating unit (III) represented by the formula (III) wherein R10 to R12 each independently represents hydrogen or C1-10 hydrocarbon and R13 represents aryl or heteroaryl; and wherein an arrangement order thereof is B, A, B.