Abstract: A heat sensitive recording sheet having a heat sensitive color forming layer wherein a mixture of fluoran compounds of the following formulas I and II is used as a color former; ##STR1## wherein R.sub.1 is a hydrogen atom, an alkyl group having from 1 to 8 carbon atoms, a tetrahydrofurfuryl group, a substituted or unsubstituted phenyl group or a cycloalkyl group, R.sub.2 is a hydrogen atom, a chlorine atom, a fluorine atom, a lower alkyl group, a lower alkoxy group, a lower alkoxyalkyl group, a phenyl group or a benzyl group, and R.sub.3 is a hydrogen atom, a chlorine atom, a fluorine atom, a bromine atom, a lower alkyl group or an acyl group; and ##STR2## wherein each of R.sub.4 and R.sub.5 is a hydrogen atom, an alkyl group having from 1 to 8 carbon atoms, a substituted or unsubstituted phenyl group or a cycloalkyl group, or R.sup.4 and R.sub.5 may, together with the adjacent nitrogen atom, form a ring of the formula ##STR3## each of R.sub.6 and R.sub.

Abstract: A 2,4-5-triphenylimidazole compound having the formula: ##STR1## wherein each of R.sub.1 to R.sub.5 is a hydrogen atom, a C.sub.1 -C.sub.4 alkyl group, a C.sub.1 -C.sub.4 alkoxy group, a fluorine atom, a chlorine atom, a bromine atom, a trifluoromethyl group or a trichloromethyl group, and A is a group having the formula: ##STR2## wherein R.sub.1 and R.sub.5 are as defined above. These compounds are useful as chlorine sources for photographic image-forming compositions, and as intermediates for dimers of 2,4-5-triphenylimidazoles which are useful as photochromic agents in sunglasses.

Abstract: This invention relates to a xanthene derivative that develops color on oxidation, so that it is favorably used for a photoresist, a PS plate or a proofing agent. The xanthene derivative, which has the following structural formula (I), is produced by putting a fluoran derivative represented by the following structural formula (II) to an esterification reaction and then to a reduction reaction. ##STR1## In the above formulae R.sub.1 and R.sub.2 independently stand for hydrogen, an alkyl radical with 1 to 8 carbon atoms, a tetrahydrofurfuryl radical, a substitued or an unsubstituted phenyl radical, a substituted or an unsubstituted benzyl radical or a cyclic alkyl radical; in addition, R.sub.1 and R.sub.2 are able to form a ring in pairs. R.sub.3 and R.sub.6 independently stand for hydrogen, chlorine, fluorine, a lower alkyl radical or a lower alkoxy radical. R.sub.4 and R.sub.

Abstract: A novel 6-tetrahydrofurfurylaminofluoran compound useful as a color former (precursory colorant) for a heat-sensitive recording sheet is of the formula (I): ##STR1## wherein R.sub.1 is H, C.sub.1-8 alkyl, tetrahydrofurfuryl, phenyl alkyl(C.sub.1-5)phenyl, or C.sub.3-8 cyclic alkyl, R.sub.2 is H, Cl, F, C.sub.1-5 alkyl, C.sub.1-5 alkoxy, C.sub.2-10 alkoxyalkyl, phenyl or benzyl, and R.sub.3 is H, Cl, F, C.sub.1-5 alkyl and C.sub.2-7 acryl.

Abstract: A novel 6-tetrahydrofurfurylaminofluoran compound useful as a color former (precursory colorant) for a heat-sensitive recording sheet is of the formula (I): ##STR1## wherein R.sub.1 is H, C.sub.1-8 alkyl, tetrahydrofurfuryl, phenyl, alkyl(C.sub.1-5)phenyl, or C.sub.3-8 cyclic alkyl, R.sub.2 is H, Cl, F, C.sub.1-5 alkyl, C.sub.1-5 alkoxy, C.sub.2-10 alkoxyalkyl, phenyl or benzyl, and R.sub.3 is H, Cl, F, C.sub.1-5 alkyl and C.sub.2-7 acryl.