To provide an organic EL element having light emitting efficiency and excellent in durability by containing specific quantities of two kinds of specific structure polymers.
An electric charge transport material is composed of 5 to 95 wt.% of a polymer A composed of a structure unit expressed by formula I and 5 to 95 wt.% of a polymer B composed of a structure unit expressed by formula II. In both formulas, R1 and R2 independently represent a hydrogen atom, alkyl group, alkoxy group or dialkyl amino group, X represents a single bond, alkylene group or an arylene group. R3 represents an alkyl group, aryl group or an aralkyl group, and Z represents a bivalent organic group expressed by formula III or formula IV. Here, R4 represents an hydrogen atom or an alkyl group. It is desirable that weight average molecular weight of the polymer A is 3,000 to 1,000,000 in terms of polystyrene by, for example, a gel permeation chromatography, and weight average molecular weight of the polymer B is 2,000 to 1,000,000.
TAKEUCHI YASUMASA
Next Patent: ORGANIC EL ELEMENT AND MANUFACTURE THEREFOR