Patent ID: 7166689

Claim:
A polymer comprising a repeat unit represented by the following formula (I), wherein the polymer is end-capped by a phenyl group: wherein, Ar 1 represents a substituted aromatic hydrocarbon group or a non-substituted aromatic hydrocarbon group, Ar 2 and Ar 3 each, independently, represent a divalent aromatic hydrocarbon selected from the group consisting of substituted or non-substituted monocyclic aromatic hydrocarbons, substituted or non-substituted non-condensed polycylic aromatic hydrocarbons and substituted or a non-substituted condensed polycylic aromatic hydrocarbons and Ar 4 represents a bivalent group of benzene, thiophene, biphenyl or anthracene, each of which can optionally have a substituent.