MODIFICATION OF 3,3-BIS(2,2-BIS(P-DIMETHYLAMINOPHENYL) ETHENYL)-4,5,6,7-TETR-ACHLOROPHTHALIDE CRYSTAL AND COLOR-FORMING RECORDING MEDIUM PREPARED THEREFROM

摘要

PURPOSE:To obtain the title crystal modification useful as a coupler excellent in color forming property, density of formed color, stability of formed color image, light resistance of ground, etc. in the near-infrared region, which exhibits strong peaks at specified angles of diffraction in X-ray diffractometry with Cu-K alpha-line. CONSTITUTION:A deposition obtained by reacting tetrachlorophthalic acid (A) with 2mol, per mol. of component A, 1,1-bis(p-dimethylaminophenyl)ethylene (B) at 50-100 deg.C for several hr in the presence of a condensing agent (e.g., acetic anhydride) is dissolved in a mixture of an aqueous alkali solution with an organic solvent at 80-90 deg.C, and the organic solvent layer is concentrated to obtain alpha-modification of 3,3-bis[2,2bis(p-dimethylaminophenyl)ethenyl]-4,5,6,7- tetra-chlorophthalide of the formula. This alpha-modification is dissolved in 5-10pts. wt., per pt.wt. this alpha-modification, chloroalkane, and crystallized to obtain the title compound beta-modification exhibits strong peaks at angles of diffraction (2theta) 7.5, 12.8, 20.6, 21.8, 24.2, 25.8 and 27.1 in X-ray diffractometry with the Cr-K alpha-line.