| 摘要 |
PURPOSE:To obtain a color-developed image with high resistance against plasti cizer and oil by adding a substatially colorless dye precursor and a chemical compound of specific structure as a color developer which chemically reacts with the dyeprecursor under heating, to a thermal color development layer. CONSTITUTION:A chemical compound containing two or more groups with a skeletal structure of 4,4'-dihydroxydiphenylsulfone(BPS) expressed by formula I is added as a color developer. This multi(BPS structure)chemical compound contains two(BPS structure)chemical compounds or three(BPS structure) chemical compounds having the second or third position of the BPS structure bonded to the second or third position of another BPS structure through a methylene group, and can contain a substituted group such as an alkyl group, a methylol group or halogen. In addition, the recommanded substantially colorless electron- donative dye precursors are 3-dibutylamino-6-methyl-7-anilinofluoran, 3-(N- isoamyl-N-ethylamino)-6-methyl-7-anilinofluoran. |
