Aminobenzenesulfonamide derivative and recording medium using the same

A thermal recording medium comprising a substrate having thereon a recording layer containing a colorless or pale colored dye precursor, and a color developer reactable with the dye precursor to develop a color as main ingredients, wherein the color developer includes at least one compound of Formula (2):

• ##STR7## wherein X is oxygen atom or sulfur atom, Y is a lower alkyl group of 1 to 6 carbon atoms or an electron attracting group and m is an integer from 0 to 3.

A thermal recording medium comprising a substrate having thereon a recording layer containing a colorless or pale colored dye precursor, and a color developer reactable with the dye precursor to develop a color as main ingredients, wherein the color developer includes at least one compound of Formula:

• ##STR14## wherein X is sulfur atom;
• and R is a substituted or unsubstituted group which is selected from the group consisting of phenyl group, naphthyl group, aralkyl group, a lower alkyl group of 1 to 6 carbon atoms, cycloalkyl graup, and a lower alkenyl group of 2 to 6 carbon atoms, Z is a lower alkyl group of 1 to 6 carbon atoms or an electron attracting group, and n is an integer from 0 to 4.

A thermal recording medium comprising a substrate having thereon a recording layer containing a colorless or pale colored dye precursor, and a color developer reactable with the dye precursor to develop a color as main ingredients, wherein the color developer includes at least one compound of Formula:

• ##STR18## wherein X is sulfur atom, Y is a lower alkyl group of 1 to 6 carbon atoms or an electron attracting group, and m is an integer from 0 to 3.