BLUE LIGHT EMITTING MATERIAL HAVING COLOR PURITY Y COORDINATE OF 0.10 WITHOUT USING ADDITIONAL DOPANT OBTAINED FROM 1,2,4,5-TETRAKIS(4-FORMYLPHENYL)BENZENE AND PREPARATION METHOD THEREOF

PURPOSE: Provided are a blue light emitting material which is obtained from 1,2,4,5-tetrakis(4-formylphenyl)benzene and shows an excellent heat resistance due to high glass transition temperature and an excellent color purity when used as a material for an organic electroluminescent device and its preparation method. CONSTITUTION: The blue light emitting material is represented by the formula 1, wherein R is a 2,2-diarylvinyl group, a 2-arylvinyl group or a 9-fluorenylmethylenyl group. The material is prepared by reacting the 1,2,4,5-tetrakis(4-formylphenyl)benzene represented by the formula 5 with a phosphonate compound represented by the formula 4 in the presence of a solvent and a base, wherein R1 is a diarylmethyl group, an arylmethyl group or a 9-fluorenyl group. Preferably the base is at least one selected from the group consisting of sodium hydride, lithium hydride, potassium hydride, sodium t-butoxide and potassium t-butoxide; and the ratio of the phosphonate compound of the formula 4 to the 1,2,4,5-tetrakis(4-formylphenyl)benzene is 4-6 : 1 by equivalence.