Patent ID: 6984459

Claim:
A polymeric fluorescent substance which emits a fluorescence in solid state and has a number-average molecular weight of 10 3 to 10 8 in terms of polystyrene, wherein the substance contains two repeating units represented by the following formula (1) and formula (3), and these repeating units are so selected as to satisfy the following conditions (a) to (c): (a): the total amount of the repeating units represented by the formulae (1) and (3) is 50 mol % or more of the amount of the whole repeating units, (b): the amount of the repeating unit represented by the formula (3) is more than 0.1 mol % and less than 9 mol % based on the total amount of the repeating units represented by the formula (1) and formula (3), and (c): when the absorption edge wavelength of a polymer solely composed of a repeating unit represented by the formula (1) is represented by λ 1 (nm) and the absorption edge wavelength of a polymer solely composed of a repeating unit represented by the formula (3) is represented by λ 2 (nm), the following relation is satisfied: in the formula, Ar 1 is a group represented by the following formula (5); R 1 and R 2 each independently represents a group selected from the group consisting of a hydrogen atom, alkyl group having 1 to 20 carbon atoms, aryl group having 6 to 60 carbon atoms, heterocyclic compound group having 4 to 60 carbon atoms and cyano group; and n is 0 or 1, in the formula, X 1 to X 12 each independently represents C—R 7 ; wherein, each R 7 independently represents a group selected from the group consisting of a hydrogen atom, alkyl group having 1 to 20 carbon atoms, alkoxy group having 1 to 20 carbon atoms, alkylthio group having 1 to 20 carbon atoms, alkylsilyl group having 1 to 60 carbon atoms, alkylamino group having 1 to 40 carbon atoms, aryl group having 6 to 60 carbon atoms, aryloxy group having 6 to 60 carbon atoms, arylalkyl group having 7 to 60 carbon atoms, arylalkoxy group having 7 to 60 carbon atoms, arylalkenyl group having 8 to 60 carbon atoms, arylalkynyl group having 8 to 60 carbon atoms, arylamino group having 6 to 60 carbon atoms, heterocyclic compound group having 4 to 60 carbon atoms and cyano group; at least one R 7 is a group other than a hydrogen atom; adjacent 6-membered rings may be mutually connected directly or via a substituent to form a ring; j is an integer from 0 to 3; wherein, X 1 and X 9 , X 2 and X 10 , X 3 and X 11 , and X 4 and X 12 are not respectively the same simultaneously, and X 1 and X 12 , X 2 and X 11 , X 3 and X 10 , and X 4 and X 9 are not respectively the same simultaneously, in the formula, Ar 5 represents an arylene group having 6 to 60 carbon atoms contained in the main chain; R 3 and R 4 each independently represents a group selected from the group consisting of a hydrogen atom, alkyl group having 1 to 20 carbon atoms, aryl group having 6 to 60 carbon atoms, heterocyclic compound group having 4 to 60 carbon atoms and cyano group; 1 is 1.