| 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 specific antipyrine complex of zinc thiocyanate as a color developer but also a specific compound as an assistant component. CONSTITUTION:An antipyrine complex of zinc thiocyanate represented by formula I is used as a color developer and at least one of compounds represented by general formula II (wherein R is an alkylene group having at least one hydroxyl group and each of rings A, B are a benzene nucleus, and said alkylene group and said rings A, B may have substitutent selected from an alkyl group, an aralkyl group, and aryl group, and alkoxy group and a halogen atom) is used as an auxiliary component. As the compounds represented by the general formula II, ones having m.p. of 40-150 deg.C, are pref. and ones having m.p. of 50-120 deg.C are especially pref. from the aspect of storage stability and sensitivity as a thermal recording material. Leuco dyes are used alone or as a mixture of two or more kinds of said dyes. As said leuco dyes. ones adapted to this kind of the thermal recording material may be arbitrarily selected. |
