| 摘要 |
PURPOSE:To prevent the lowering in the density of an image even if said image is contacted with water, for example, immersed in water, by using not only a specific zinc complex as a color developer but also a specific dithioethyer compound as an assistant component. CONSTITUTION:A zinc complex represented by general formula I (wherein R is an org. ligand capable of forming a complex by the bonding to a zinc ion through a heteroatom, (k) is 2 or 4 and (X) is SCN or a halogen atom) is used as a coupler and at least one of the compounds represented by general formula II (wherein R is a 1-12C hydrocarbon group which has one or more of a double bond and may have a branch chain, X and Y may be the same or different and are a lower alkyl group, an alkoxy group, an aryl group, an acyloxy group, and aralkyl group or a halogen atom and m and n are independently an integer of 0-3) is used together as an assistant component. The zinc complex represented by the general formula I and the dithioether compound represented by the general formula II together used as the assistant component have pref. m.p. of 40-150 deg.C and especially pref. m.p. of 50-120 deg.C from the aspect of storage stability and sensitivity as a thermal recording material. The thermal recording material is prepared by applying a coating liquid for forming a thermal layer containing both components to a proper support such as paper, synthetic paper or a plastic film and drying the same. In this case, the proper use amounts of a leuco due, the coupler and a color forming sensitivity sensitizer are respectively 5-40wt%, 20-60wt% and 20-60wt%. |
