| 摘要 |
PURPOSE:To obtain a thermal recording material capable of providing a developed color image with excellent stability, particularly, water resistance, by using a specified phenolic compound as a color developer, in a thermal recording material utilizing a color forming reaction between a leuco dye and a color developer. CONSTITUTION:The phenolic substance of the formula, wherein X is a lower alkyl group or a halogen, and n is an integer of 0-3, used as the color developer is a p-hydroxyphenyl ester of benzenetiosulfonic acid which may be substituted by a lower alkyl group or a halogen, and concrete examples thereof include S-4'- hydroxyphenyl benzenetiosulfonate (in the formula, n=0) and S-4'- hydroxypheynl 4-methylbenzenethiosulfonate (in the formula, X=CH3 and n= 1). The compound of the formula is used in an amount of generally 1-10 times, preferably, 2-5 times (by weight) of that of the leuco dye. |
