A heat-sensitive recording material in which a heat-sensitive color-developing layer comprising, as the main components, a usually colorless or light-colored color former and a developer capable of developing the color former upon heating on a support, characterized by comprising, as the developer, crystals of 3,3'-diallyl-4,4'-dihydroxy-diphenyl sulfone which have DSC (Te) of at least 149°C and which are of a crystal form characterized by an X-ray diffraction pattern having peaks at least at diffraction angles (2θ) [°] of 7.2 and 22.0, obtained by an X-ray powder diffractometry using Cu-Kα rays. This heat-sensitive recording material is high in sensitivity, little in Discoloration of the ground in heat and moisture and excellent in image durability.
一种热敏记录材料,其热敏显色层的主要成分包括通常为无色或浅色的
显色剂和在支持物上加热后能使
显色剂显色的显影剂,其特征在于包括、作为显影剂,3,3'-
二烯丙基-4,4'-二羟基
二苯砜的晶体,其
DSC(Te)至少为 149°C,其晶体形态的 X 射线衍射图的特征是至少在衍射角(2θ)[°]为 7.2 和 22.0 的 X 射线粉末衍射图。这种热敏记录材料灵敏度高,在高温和
潮湿条件下地面变色小,图像耐久性好。