Abstract: This invention provides a heat-sensitive record material comprising a base sheet and a heat-sensitive record layer formed over the base sheet and containing a colorless or pale-colored basic dye and a color developing material capable of forming a color when contacted with the dye, the record material being characterized in that the heat-sensitive record layer contains as the color developing material at least one compound represented by the formula ##STR1## wherein R.sub.1 and R.sub.2 are each alkyl having 1 to 8 carbon atoms, a group ##STR2## or a group ##STR3## wherein R.sub.3 and R.sub.4 are each a hydrogen atom, chlorine atom, hydroxyl or alkoxy having 1 to 8 carbon atoms, the heat-sensitive record layer further containing at least one compound selected from the group consisting of 1,1-bis(4-hydroxyphenyl)cyclohexane and hindered phenol compounds.

Abstract: Novel phenolic compounds useful as a color developer suitable for satisfying the quality requirements of heat-sensitive recording materials are provided, which compounds are expressed by the general formula ##STR1## wherein R.sub.1 represents an alkyl group or a cycloalkyl group and R.sub.2 represents hydrogen atom or an alkyl group; and also heat-sensitive recording materials usable in a broad application field are provided, which recording materials are provided with a heat-sensitive recording layer composed mainly of a colorless basic dye and the above compounds as a color developer by which the dye forms colors, overlaid on a substrate.

Abstract: In a heat-sensitive recording material incorporating a colorless or pale-colored basic dye and a color acceptor which is reactive with the basic dye to form a color when contacted therewith, the recording material characterized in that at least one compound represented by the formula [I] is contained in a heat-sensitive recording layer ##STR1## wherein X is --O-- or --COO--, R.sub.1 to R.sub.4 are each hydrogen atom, alkyl having 1 to 8 carbon atoms, aryl having 6 to 10 carbon atoms, aralkyl having 7 to 9 carbon atoms, chlorine atom, acetyl, propionyl, methoxy, methylthio, methoxycarbonyl, cyano, nitro or cyclohexenyl, substituents R.sub.1 and/or R.sub.2 or substituents R.sub.3 and R.sub.4 may link together to form aromatic ring(s), n is an integer of 1 to 10.

Abstract: A heat-sensitive material comprising a support having formed thereon a heat-sensitive recording layer, which has a high whiteness and is suitable for use in high-speed recording, is disclosed. The heat-sensitive recording layer comprises a colorless or pale-colored basic dye and a color developing material that, when heated, reacts with the basic dye to form a color, wherein the heat-sensitive recording layer further comprises at least one heat-fusible material having a melting point in the range of 70.degree. C. to 140.degree. C. and selected from the compounds represented by following formulae (I) to (VI): ##STR1## wherein R.sub.1, R.sub.2, R.sub.5, R.sub.6, and R.sub.7 independently represent a phenyl group, a benzyl group, or a tolyl group, each of which groups may be substituted with a halogen atom; and R.sub.3 and R.sub.

Abstract: In a heat-sensitive recording material incorporating a colorless or pale-colored basic dye and a color acceptor which is reactive with the dye to form a color when contacted therewith, the recording material characterized in that the color acceptor comprises at least one compound represented by the formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each a hydrogen atom, alkyl having 1 to 8 carbon atoms, aryl or aralkyl, provided that R.sub.1 and R.sub.2, as well as R.sub.3 and R.sub.4, are not hydrogen at the same time.

Abstract: A heat-sensitive recording material comprising a support having a recording layer provided thereon, the recording layer comprising a colorless or pale-colored basic dye and a color developing material, wherein the recording layer further comprises at least one heat-fusible material represented by the formula (I) or (II): ##STR1## wherein R.sub.1 to R.sub.17 independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a phenyl group, a benzyl group, or a benzyloxy group.

Abstract: A heat-sensitive recording material comprised of a heat-sensitive layer on a support is disclosed. The layer comprises a colorless or pale-colored basic dye and a color developing material that, when heated, reacts with the basic dye to form a color. The color developing material is made of a compound having the general formula (I): ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 independently represent hydrogen or a hydroxyl group.

Abstract: A heat-sensitive recording material is described comprising a support having a recording layer provided thereon, said recording layer containing (1) at least one colorless or pale-colored basic dye, (2) hydroquinone monobenzyl ether, and (3) at least one compound selected from compounds represented by the formulae (I) to (IV): ##STR1## wherein X and Y are each a chlorine atom, an alkyl group having 1 to 7 carbon atoms, a phenyl group or a benzyl group; m and n are each an integer of 0 to 3; and R.sub.1 and R.sub.2 are each a hydrogen atom, an alkyl group having 1 to 7 carbon atoms, a phenyl group or a benzyl group, or R.sub.1 and R.sub.2 may jointly form a cyclohexane ring. The heat-sensitive recording material is suitable for use in high-speed recording, e.g., high-speed facsimiles.