| 摘要 |
PURPOSE:To obtain a diazo thermal recording material having an excellent black color forming property, favorable preservability and light fading resistance, by using a specified blue color forming coupler and a specified yellow color forming coupler in combination. CONSTITUTION:A blue color forming coupler of general formula ( I ), wherein each of R<1> and R<2> is hydrogen or lower alkyl, particularly, 1-4C alkyl, and a yellow color forming coupler of general formula (II), wherein each of R<1> and R<4> is hydrogen, lower alkyl, preferably, 1-4C alkyl, and each of R<2> and R<3> is lower alkyl, preferably, 1-4C alkyl, are used in combination as couplers in a diazo thermal recording material comprising a diazo compound, a coupler and a heat- fusible substance supported on a base. The blue coupler and the yellow coupler are preferably used in a weight ratio of 1:5-5:1. The combination of the couplers yields a diazo thermal recording material capable of forming a color of pure black tone with high density. |
