摘要 |
PROBLEM TO BE SOLVED: To provide a thermal recording material wherein image retention and heat resistant ground color stability are drastically improved. SOLUTION: A thermal recording material is provided wherein a compound having an N-formamide group (-NHCHO) and a carbonylsulfonamide group (-SO2 NHCO-) which are expressed by the formula (wherein either of A1 or A2 is an N-formamide group, and the other expresses a hydrogen atom, R1 or R2 respectively independently expresses a hydrogen atom, an alkyl group, an alkoxyl group, a halogen atom, an acyl group, an alkokyl carbonyl group, and substituted or non-substituted aryl group.) is used as a developer. Though the compound has not a phenolic OH group, it has a developing capability for coloring a dye precursor with the N-formamide group and the carbonylsulfonamide group which present an acidic atmosphere. Further, by being compared with a conventionally used phenolic developer or the like, propeties which are excellent in image retention of a recording part and heat resistant ground color stability are presented. |