abstract |
A method for producing a polymeric fluorescent substance characterized by comprising the step of contacting with an alkali a crude polymeric fluorescent substance that is fluorescent in a solid state and has a polystyrene equivalent number average molecular weight of 10 4 to 10 8 and one or more repeating units represented by the following formula (1): n —Ar 1 —(CR 1 ═CR 2 ) n — ( 1 ) n wherein Ar 1 is an arylene group or heterocyclic compound group that is unsubstituted or substituted by one or more substituents; R 1 and R 2 each independently represent a group selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group, a heterocyclic compound group and a cyano group, in which the aryl group and the heterocyclic compound group is optionally substituted by another substituent; and n is 0 or 1. |