| abstract |
A new fluoran derivative useful as a colorless chromogenic material has the following formula:wherein R is cyclopentyl, cycloheptyl, cyclohexylmethyl or cyclohexyl substituted by at least one alkyl and having 7 to 10 carbon atoms; each R , R<sub>2 </sub>and R<sub>3</sub> is hydrogen, an alkyl having 1 to 18 carbon atoms which may be substituted by at least one substituent selected from the group consisting of halogen atoms, alkoxyls and cyano, or an aralkyl which may be substituted by at least one substituent selected from the group consisting of halogen atoms, lower alkyls and lower alkoxyls, or both or R<sub>2</sub> and R<sub>3</sub> together with the adjacent nitrogen may from a heterocyclic ring which may include an oxygen or another nitrogen, or R<sub>3</sub> is a cycloalkyl or aryl which may be substituted by at least one substituent selected from the group consisting of halogen atoms, lower alkyls, substituted alkyls, lower alkoxyls, amino, substituted aminos and acyls; each X and Y is hydrogen, a halogen atom or a lower alkyl or Y is a lower alkoxyl. |