Patent ID: 7982212

Claim:
A copolymer comprising a repeating unit of the following formula (1) and a repeating unit of the following formula (2): wherein, a ring A and ring B represent each independently an aromatic ring optionally having a substituent; X is —O—, —S—, —S(═O)—, —S(═O) 2 —, —Si(R 1 ) 2 —, —Si(R 1 ) 2 —, —Si(R 1 ) 2 —, —B(R 1 )—, —P(R 1 )—, —P(═O)(R 1 )—, —O—C(R 1 ) 2 — or —N═C(R 1 )—, and R 1 represents a substituent; and when there are two or more R 1 in the same formula, they may be the same or different; wherein, Y is —O—, —S— or —C(═O)—; Ar 1 represents an aryl group optionally having a substituent or a monovalent heterocyclic group optionally having a substituent, and there is no substituent connected to atoms of the ring of Ar 1 , the atoms being adjacent an atom of Ar 1 connected to a nitrogen atom in the formula; R 2 represents a substituent, and n represents an integer of from 0 to 3; and when there are two or more R 2 in the formula, they may be the same or different.