| 摘要 |
PURPOSE:To increase thermal response and enhance coloring density by adding a dithioacetal compound to a thermal recording material containing a normally colorless or pale dye precursor and an electron-receptive compound which causes the dye precursor to develop a color through chemical reaction when heated. CONSTITUTION:A compound expressed by formula I is added to a thermal recording material containing a normally colorless or pale dye precursor and an electron-receptive compound which causes the dye precursor to develop a color through chemical reaction when heated. (Z1, Z2 are an alkyl, a hydroxyalkyl or an aralkyl group, or a substitute of the former, and may be different from each other, or may form a 2C or more alkylene chain with the connected terminals of Z1 and Z2 and may have an alkyl group in the side chain). In addition, the compound should preferably have a melting-point range of about 60 to 160 deg.C for practical use, if it is to be used as a thermal recording material. Further, the compound can be easily compounded using a well known technique and also can be easily refined. |
