Abstract: The present invention provides a recording material utilizing the color forming reaction between a colorless or light-colored basic dye and a color acceptor reactive with the dye to form a color and forming on the same or different substrate layer or layers containing the basic dye and the color acceptor conjointly or separately, the recording material being characterized in that the color acceptor is at least one of salicylic acid derivatives represented by the following formula [I] or polyvalent metal salts thereof ##STR1## wherein X is straight-chain or branched-chain C.sub.1.about.12 alkylene or C.sub.5.about.12 cycloalkylene, R is C.sub.1.about.20 alkyl having or not having a substituent or C.sub.2.about.20 alkenyl having or not having a substituent, Y is C.sub.1.about.6 alkyl, C.sub.2.about.6 alkenyl, C.sub.7.about.10 aralkyl or halogen atom, Z is C.sub.1.about.6 alkyl, C.sub.2.about.6 alkenyl, C.sub.7.about.10 aralkyl, C.sub.1.about.

Abstract: A recording material utilizing the reaction between a colorless or light-colored basic dye and a color acceptor reactive with the basic dye to form a color and forming on the same or different substrate a layer or layers containing the basic dye of the color acceptor conjointly or separately, the recording material being characterized in that the color acceptor is at least one of salicyclic acid derivatives represented by the following formula [I] or polyvalent metal salts thereof ##STR1## wherein Ar, R, X, l and m are defined in the specification.

Abstract: A heat sensitive recording material comprising a substrate and a recording layer thereon incorporating a colorless or light-colored basic dye and a color acceptor reactive with the dye to form a color when contacted therewith, the recording material being characterized in that, as the color acceptor is used at least one compound selected from the group consisting of 4-hydroxy-4'-isopropyloxydiphenylsulfone, 4,4'-(1,3-dimethylbutylidene) bisphenol, 4,4'-(1-phenylethylidene)bisphenol, 4,4'-(p-phenylenediisopropylidene)bisphenol and 4,4'-(m-phenylenediisopropylidene) bisphenol, and to the recording layer is added at least one of a heat-fusible substance represented by the formula [I] ##STR1## wherein X is hydrogen atom, halogen atom, C.sub.1.about.4 alkyl or C.sub.1.about.4 alkoxy.

Abstract: A heat sensitive recording material comprising a substrate and a heat sensitive recording layer thereon incorporating a colorless or light-colored basic dye and a color acceptor reactive with the dye to form a color when contacted therewith, the recording material being characterized in that, as the color acceptor is used at least one compound of the formula [I] ##STR1## wherein R is an alkylene group having at least one bond selected from the group consisting of ester bond and amido bond in the main chain, R.sub.1 and R.sub.2 are each hydrogen atom, alkyl, cycloalkyl, alkenyl, alkoxyl, hydroxyl or halogen atom.

Abstract: The heat-sensitive record material according to this invention has a heat-sensitive recording layer on a base sheet, which comprises a colorless or pale colored basic chromogenic material and a phenolic compound developing a color by contacting with the chromogenic material. The recording layer comprises, as the basic chromogenic material, at least one fluoran derivative represented by the following formula [I] and at least one phthalide derivative represented by the following formula [II] in a weight ratio of 100:1.about.20; ##STR1## wherein each R.sub.1, R.sub.2 represents alkyl, unsaturated alkyl, cycloalkyl, aryl, aralkyl or tetrahydrofurfuryl, each of which may have at least one substituent selected from the group consisting of halogen, alkyl and alkoxyl, R.sub.1 may cooperate with R.sub.2 to form a ring, each R.sub.3, 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 (a) as the basic dye are used 100 parts by weight of a specific phthalide derivative of the formula [I] and 20 to 100 parts by weight of a specific black color-forming fluoran derivative of the formula [II], (b) as the color acceptor is used a polyvalent metal salt of an aromatic carboxylic acid and (c) a recording sensitizer is further used, and whereby the resulting record images are at least 0.75 in PCS value at 800 nm.