To obtain a heat developable diazo copying material for a black forming mother print which does not cause surface fog, maintains raw stock preservability over a long period of time and is excellent in light shielding property by using a specified compd. as a coupling component in a diazo copying material.
In a diazo copying material obtd. by coating the top of a substrate with a recording layer contg. a diazo compd. and a coupling component as constituents, a compd. having an active methylene group represented by the formula is used as the coupling component. In order to enable heat development while maintaining preservability over a long period of time, a two-layered structure consisting of a photosensitive layer contg. the diazo compd. and a coupler layer contg. the coupling component is imparted. In the formula, X is cyano, acetyl, benzoyl or -COOR1, R1 is alkyl, or benzyl and (n) is an integer of 0-6. The coupling component has a substituent having an active methylene group in an amino group at the 1-position and forms a light shielding yellow image.
MATSUDA TSUTOMU
HIRABAYASHI TAKEO
SHIMODA NAOTO
