Abstract: Disclosed is a heat-sensitive recording material comprising a base sheet and a heat-sensitive record layer formed over the base sheet and comprising a colorless or pale-colored basic dye and a color developing material capable of forming a color when contacted with the dye, the heat-sensitive recording material being characterized in that the heat-sensitive record layer contains as the color developing material at least one multi-valent metal salt of a halophthalic acid derivative represented by the formula ##STR1## wherein R represents a divalent saturated or unsaturated C.sub.2 -C.sub.12 aliphatic hydrocarbon group which may optionally have a hydroxyl, C.sub.1 -C.sub.3 acyloxy or phenyl group as a substituent or a divalent saturated or unsaturated C.sub.4 -C.sub.6 aliphatic hydrocarbon group containing one or two ether bonds, X is a halogen atom and n is an integer of 1-4.

Abstract: An improved heat sensitive recording sheet having a wealth of high speed recording characteristics and remarkably improved resistances against plasticizers and against diazo developers which contain at least a 3,4-dihydroxydiphenyl sulfone derivative.

Abstract: Cycloalkyl aminophenol derivatives are produced by reacting o-, m- or p-aminophenol with a cycloalkanone having 5 to 12 carbon atoms in the presence of a reducing agent and preferably with the addition of an acid.

Abstract: Fluoran compounds of the structural formula: ##STR1## wherein R.sub.1 is propyl or butyl, R.sub.2 is an alkyl of from one to four carbon atoms, R.sub.3 is methyl or ethyl, and R.sub.4 is hydrogen or methyl are particularly suitable for use in providing high quality pressure, heat or electrothermal sensitive recording sheets containing a color former in operative association with an electron-accepting substance.

Abstract: A new fluoran derivative useful as a colorless chromogenic material has the general formula: ##STR1## wherein R.sub.1, R.sub.2, X, Y and Z have the same meaning as defined hereinbefore.