| abstract |
A thermally sensitive recording sheet which comprises, on a substrate, a thermally sensitive color developing layer comprising:n (a) a colourless or pale coloured basic leuco dye; (b) an organic color developer which is an aminobenzenesulfonamide derivative of the following formula (I):n wherein X is oxygen or sulfur, Y is C 1 -C 4 alkyl or an electron attracting group, m is 0 or an integer of 0 to 4 and R is unsubstituted or substituted phenyl, aralkyl, C 1 -C 6 alkyl, C 3 -C 6 cycloalkyl C 2 -C 6 alkenyl or naphthyl; and (c) a sensitizer which is a sulfonamide compound of the following formula (II), present in an amount of 0.01 - 2 parts by weight based on 1 part by weight of the organic colour developer of formula (I) which is component (b):n wherein Z is C 1 -C 6 alkyl or an electron attracting group and n is 0, 1 or 2. |