To provide a resin composition having excellent heat resistance, optical characteristics and mechanical characteristics; and to provide an optical part such as a transparent electroconductive film base, a TFT substrate, a substrate for a liquid crystal display, a substrate for an organic EL display, a substrate for electronic paper, a substrate for a solar battery, a substrate for an optical disc, an optical waveguide, an optical fiber, a lens and a touch panel, an optical film, and a flat panel display using the optical film base as the substrate by using the resin composition.

The resin composition contains a chemical structure represented by general formula (1) (wherein, R1 to R4 are each independently a hydrogen atom or a substituent; R5 and R6 are each independently a substituent; m and n are each an integer of 0-4; with the proviso that when m and/or n is ≥2, R5 and/or R6 is the same or different and R5 and R6 may form a 5- to 7-membered ring by bonding to each other) in the main chain of a polymer.