| 摘要 |
PURPOSE:To contrive higher color forming properties, preservability and stability of developed color images, by using a specified electron-acceptive compound in a recording material such as a pressure-sensitive recording paper, a thermal recording paper, a photo- and pressure- sensitive recording paper and an electrothermal recording paper using an electron-donative colorless dye and an electron-acceptive compound. CONSTITUTION:An electron-acceptive compound of the formula HOAr1CO2[CnH2nO]mAr2 (formula I) is used in a recording material utilizing a color forming reaction upon contact of an electron-donative colorless dye with an electron-acceptive compound. Among the compounds of formula I, one having a plurality of ether linkages is particularly preferable. Further, such a compound having a melting point of 60-220 deg.C, 15-32 carbon atoms and a solubility in hot water of 50 deg.C of not more than 0.3 is preferred. When the compound of formula (I) is used in combination with a compound of the formula Ar2O[CnH2nO]mAr1 CO2[CnH2nO]-mAr2 (formula II), various characteristics such as an increase in sensitivity due to lowering of the melting point, a remarkable reduction of fogging due to lowering of water solubility, prevention of decoloration of developed color images due to a crystallization-preventing action of the compound of formula (I) alone, and enhancement of brightness can be achieved. In the formulas, each of Ar1 and Ar2 is an aromatic ring, and each of n and m is a positive integer. |
