Fluoran derivatives, process for preparation thereof and recording material containing the same

Abstract From the Canadian patent

A fluoran derivative useful for a heat-sensitive recording material, having the following general formula I;, ...I, wherein R1 and R2, which may be the same or different, stand for an alkyl group having 1 to 9 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, a phenyl group or a phenyl group substituted by an alkyl group having 1 to 4 carbon atoms, and R3 and R4 , which may be the same or different stand for an alkyl group having 1 to 6 carbon atoms or a phenyl group or R3 and R4 may form a 5- to 8-membered cycloalkane together with the carbon atom to which they are bonded.