| 摘要 |
PURPOSE:To contrive a marked enhancement of preservability of a developed color image, by using a mixture of at least two phenolic compounds as a color developer in a thermal recording material comprising a specified divinylphthalide as a color former. CONSTITUTION:A mixture of at least two phenolic compounds is used as a color developer, in an infrared-absorbing thermal recording material comprising a divinylphthalide compound of the general formula as a color former. In the formula, each of R<1> and R<2> is an up to 8C alkyl which may have an alkoxyl as a substituent group, 5-7C cycloalkyl, aralkyl or aryl, each of X<1>, X<2> and X<3> is hydrogen, an up to 8C alkyl, up to 8C alkoxyl, aryl or halogen, and X<4> is chlorine or bromine, with the proviso that R<1> and R<2> may be linked to each other to form a heterocyclic ring. When the mixture of at least two phenolic compounds is used as the color developer, moisture resistance and plasticizer resistance are markedly enhanced, as compared with the case of using such a phenolic compound singly. Further, a visible color of a developed color image is not easily faded, and the infrared-absorbing ability of the image is not easily deteriorated. |
