| 摘要 |
PURPOSE:To obtain the stability of a color-forming image and the stability of ground color under high temperature and high humidity conditions by containing special 4-isoproboxy-4'-hydroxydiphenyl sulfone as an organic devel oper and also special monobenzylcalcium phthalate as a stabilizer in the heat sensitive color-forming layer. CONSTITUTION:Monobenzylcalcium phthalate indicated by the general expression (II) as a stabilizer is jointly used with 4-isoproboxy-4'-hydroxydiphenyl sulfone shown by the general expression (I). 4-isoproboxy-4'-hydrodiphenyl sulfone, an organic developer is a compound at melting point of 129-130 deg.C, and monobenzylcalcium phthalate is a clear high-melting-point substance (melting point: 250 deg.C or higher) obtained through the reaction of the sodium salt of monobenzil phthalate and calcium chloride. The stabilizer is added at a ratio of 10-60wt% against 4-isoproboxy-4'-hydroxydiphenyl sulfone, an organic developer. |
