Thermosensitive recording medium

摘要

A thermosensitive recording medium containing a phenol derivative represented by the chemical formula 1 as the first color developing agent and a diphenyl sulfone derivative represented by the chemical formula 2 as the second color developing agent in the thermosensitive color developing layer was shown to have excellent color developing sensitivity, moist heat resistance, heat resistance, plasticizer resistance and the like. In addition, good bar code readability and color developing sensitivity were obtained when the concentration of the diphenyl sulfone derivative used as the second color developing agent to the color developing agent in the thermosensitive color developing layer was less than 50 wt.% (particularly when the concentration was 5 wt.% to 45 wt.% in the color developing agent). The effect was pronounced when the applied energy in the printed sample was 0.28 mJ/dot [sensitivity 2 (print density), plasticizer resistance 2]. Furthermore, good bar code readability was obtained when benzyloxy naphthalene (D-2), 1,2-di(3-methylphenoxy) ethane (D-3) and bis-paramethylbenzyl oxalate (D-4) were used in the sensitizer. In contrast, good moist heat resistance could not be obtained when a diphenyl sulfone derivative as the second color developing agent was not present.