A heat-developable photographic material having improved preservability, which comprises a support having thereon at least one heat-developable photographic layer, said photographic material containing a dye represented by formula (I) ##STR1## wherein n and m each represents 0, 1, 2 or 3; p and q each represents 0 or 1; L represents a methine group or a substituted methine group; R.sub.1 and R.sub.2 are same or different and each represents an unsubstituted or substituted alkyl group; R.sub.3 and R.sub.4 are same or different and each represents a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group, an unsubstituted or substituted amino group or a halogen atom; or said R.sub.3 and R.sub.4 form a condensed 6-membered ring; Z and Z' are same or different and each represents a non-metallic atomic group necessary for forming a substituted or unsubstituted 5-membered or 6-membered ring, or substituted or unsubstituted 5-membered or 6-membered ring which is condensed with another ring; X.sup..crclbar. represents an anion; r represents 1 or 2, and when the dye forms an internal salt, r is 1.
具有改良保鲜性的热显影照相材料,包括具有至少一层热显影照相层的支持,该照相材料含有由式(I)表示的
染料
其中n和m分别表示0,1,2或3;p和q分别表示0或1;L表示亚甲基基团或取代的亚甲基基团;R1和R2相同或不同,且各自表示未取代或取代的烷基基团;R3和R4相同或不同,且各自表示氢原子,烷基基团,烷氧基,羟基,未取代或取代的
氨基或卤素原子;或R3和R4形成一个紧密的6元环;Z和Z'相同或不同,且各自表示形成取代或未取代的5元环或6元环所必需的非
金属原子基团,或与另一个环紧密结合的取代或未取代的5元环或6元环;X.sup..crclbar.表示阴离子;r表示1或2,当
染料形成内盐时,r为1。