| 摘要 |
PURPOSE:To obtain a sharp image superior in light resistance, free from background coloring, and high in color density by using a combination of a specified hydrazone type coupler and a metal salt capable of forming a chelate with a coupling product. CONSTITUTION:A diazo copying material is composed of a diazonium salt, a metal salt capable of forming a chelate with a coupling product, and as hydrazone type coupler, a pyridine deriv. represented by formula I in which R<1> is lower alkylene, and R<2> is H or lower alkyl, halogen, carboxy, or lower alkoxycarbonyl, and n is 1 or 2. This coupler rapidly reacts with the diazonium slat to give a sharp red coupling product (formazan dye). In said formula I , when R2 is H, alkyl, or halogen, the coupler is high in coupling tendency and rapidly reacts with the diazonium compd. The diazo copying material is obtained by preparing said soln. for forming the photosensitive layer using the prescribed components, and coating a support with the soln. and drying it. |
