| 摘要 |
PROBLEM TO BE SOLVED: To obtain a new benzotriazole compound useful as an ultraviolet light absorber. SOLUTION: This compound is shown by formula I (R is a 1-8C alkyl) such as 1,4-bis [2-hydroxy-3-(2H-benzotriazol-2-yl)-5-methylphenylsulfonyl]piperazine. The compound of formula I is obtained by reacting an acid chloride of formula II with piperazine in the presence of a base (e.g. triethylamine) in an inert solvent (e.g. chloroform) under cooling with ice or at a room temperature. The compound of formula I is added to at least one of a heat-sensitive recording layer or a protecting layer to give a heat-sensitive recording material improved in light resistance of a recording part and a nonrecording part without damaging basic characteristics of the recording material. A heat-sensitive material excellent in light resistance of a recordable part and an unrecordable part, chemical resistance such as plasticizer resistance, oil resistance and solvent resistance and recording and traveling properties is obtained. |
