| 摘要 |
PURPOSE:To obtain a clear high-density image with superior light resistance by combinedly using a specified pyridine deriv. and a specified coupler as a hydrazone coupler in a copying material contg. a diazonium salt, a chelate compound and a hydrazone system coupler. CONSTITUTION:The pyridine deriv. represented by formula I (where R<1> is lower alkyl, R<2> is lower alkylene, and R<3> is formula II or III) and at least one of couplers represented by formulae IV, V and VI are combinedly used as a hydrazone coupler in a copying material contg. a diazonium salt, a hydrazone system coupler and a metallic salt capable of chelating with a coupled product thereof. Such a hydrazone compound accelerates a coupling reaction by the strong electron withdrawing power of a keto group in the carbonyl group, and a formazan dye giving a clear high-density bluish black color can be obtd. as a coupled product. The fading resistance of the dye can be improved by the chelate forming metallic salt. When the couplers represented by formulae IV, V and VI are used, a black image with further improved light resistance is obtd. |
