A thermal recording sheet wherein a compound of Formula (I) or (II) is contained in a thermal color developing layer including a basic colorless dye and an organic color developer as main ingredients: ##STR1## (wherein A denotes hydrogen atom, an alkyl group of C.sub.1 to C.sub.4, an alkoxy group of C.sub.1 to C.sub.4, hydroxy group, or nitro group. R.sub.1, R.sub.2, and R.sub.3 are hydrogen atom, an alkyl group of C.sub.1 to C.sub.4, an alkoxy group of C.sub.1 to C.sub.4, hydroxy group, or nitro group. R.sub.1 and R.sub.2 may combine with each other to form an aromatic ring. Y is sulfur or oxygen atom.), ##STR2## (wherein B denotes hydrogen atom, an alkyl group of C.sub.1 to C.sub.4, an alkoxy group of C.sub.1 to C.sub.4, hydroxy group, or nitro group. R.sub.1, R.sub.2, and R.sub.3 are hydrogen atom, an alkyl group of C.sub.1 to C.sub.4, an alkoxy group of C.sub.1 to C.sub.4, hydroxy group, or nitro group. R.sub.1 and R.sub.2 may combine with each other to form an aromatic ring. Y is sulfur or oxygen atom.). The thermal recording sheet has a high sensitivity and high image stability.
一种热记录片,其中包含式(I)或(II)化合物于热显色层中,该热显色层包括以碱性无色
染料和有机
显色剂为主要成分: ##STR1## (其中A表示氢原子、C.sub.1至C.sub.4烷基、C.sub.1至C.sub.4烷氧基、羟基或硝基。R.sub.1、R.sub.2和R.sub.3表示氢原子、C.sub.1至C.sub.4烷基、C.sub.1至C.sub.4烷氧基、羟基或硝基。R.sub.1和R.sub.2可以结合形成芳香环。Y是
硫或氧原子。) , ##STR2## (其中B表示氢原子、C.sub.1至C.sub.4烷基、C.sub.1至C.sub.4烷氧基、羟基或硝基。R.sub.1、R.sub.2和R.sub.3表示氢原子、C.sub.1至C.sub.4烷基、C.sub.1至C.sub.4烷氧基、羟基或硝基。R.sub.1和R.sub.2可以结合形成芳香环。Y是
硫或氧原子。) 该热记录片具有高灵敏度和高图像稳定性。