Abstract: A heat-sensitive recording material which has a support and a heat-sensitive recording layer containing at least one carboxylate represented by the following formula (1) or (2) ##STR1## wherein a ring X is an aromatic residue which may have a substitute; the other substituents are as defined herein. The heat-sensitive recording material exhibits excellent color image stability and can provide an optically character-readable sharp image.

Abstract: A carboxylate is herein disclosed which is represented by the formula (1) or (2) ##STR1## wherein a ring X is an aromatic residue which may have a substituent; the other substitutents are as defined herein. A heat-sensitive recording material comprising this carboxylate is excellent in the stability of the color image and can provide an optically character-readable sharp color image.

Abstract: Heat-sensitive recording materials contain an electron-donating chromogenic compound and an electron-attracting compound. The recording materials also contain at least one compound represented by the following formula: ##STR1## wherein R.sub.1 and R.sub.3 mean a hydrogen atom or an alkyl, aralkyl or aryl group, R.sub.2 and R.sub.4 denote an alkyl, alkenyl, aralkyl or aryl group, X.sub.1, X.sub.2, Y.sub.1 and Y.sub.2 stand for an oxygen or a sulfur atom, and --Z.sub.1 -- and --Z.sub.2 -- are a specific aromatic group. Also provided are phenol compounds represented by the following formula: ##STR2## wherein R.sub.1, R.sub.2, X.sub.1 and Y.sub.1 have the same meanings as defined above; R.sub.5 and R.sub.6 are a hydrogen or halogen atom or an alkyl, alkoxy, aralkyl, aryl or hydroxyl group; p and q stand for an integer of 1-4; R.sub.5 and R.sub.6 may be either the same or different when p and q represent an integer of 2 or greater; and --Z.sub.3 -- means a specific divalent group.

Abstract: A heat-sensitive recording material comprising a color forming, electron donating compound and a salicylic acid derivative represented by the formula (1): ##STR1## wherein X.sub.1 and X.sub.2 are a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group or a halogen atom, Y.sub.1 and Y.sub.2 are an oxygen atom or a sulfur atom, R.sub.1 is a hydrogen atom, an alkyl group, an aralkyl group or an aryl group , and R.sub.2 is an alkyl group, an alkenyl group, an aralkyl group or an aryl group, and/or a metal salt of the salicylic acid derivative as an electron accepting compound, is disclosed.

Abstract: Disclosed are a crystal and crystalline solvate of a fluoran compound represented by the formula ##STR1## wherein R.sub.1 is ##STR2## and which are useful as chromogenic compounds in recording materials such as pressure-sensitive and heat-sensitive recording materials, a process for preparation of said crystal and said crystalline solvate, and recording materials comprising said crystal or said crystalline solvate.

Abstract: Disclosed are novel crystal of the fluoran compound represented by the formula (I) ##STR1## ,characterized by a specific X-ray diffraction diagram; preparation process thereof; and recording materials comprising the crystal.

Abstract: Disclosed are a crystal of a fluoran compound having the formula comprising exhibiting high peaks at diffraction angles (2.theta.) of 7.5.degree. and 17.0.degree. and relatively high peaks at diffraction angles (2.theta.) of 15.1.degree., 19.1.degree., 21.5.degree. and 25.3.degree. in an X-ray diffraction diagram by the CU-K.alpha. beam and a crystal of a fluoran compound having the formula (II) comprising exhibiting high peaks at diffraction angles (2.theta.) of 5.5.degree. and 19.2.degree. in an X-ray diffraction diagram by the CU-K.alpha. beam, which is useful as a color forming compound in recording materials.

Abstract: Disclosed are novel crystal of the fluoran compound represented by the formula (I) ##STR1## , characterized by a specific X-ray diffraction diagram; preparation process thereof; and recording materials comprising the crystal.

Abstract: A reversible thermochromic material, preferably in the form of a microcapsule, comprising:(a) an electron donative color former;(b) a sulfide, sulfoxide or sulfone containing a hydroxy phenyl radical; and(c) a chemical compound selected from alcohols, esters, ethers, ketones, carboxylic acids or acid amides,chromatizes very brightly and in a dense color, generates a change of chromic hue (colored - colorless) within a narrow temperature range and provides a stable thermochromatism on a long term basis.

Abstract: Heat-sensitive recording materials contain an electron-donating chromogenic compound and an electron-attracting compound. The recording materials also contain at least one compound represented by the following formula: ##STR1## wherein R.sub.1 and R.sub.3 mean a hydrogen atom or an alkyl, aralkyl or aryl group, R.sub.2 and R.sub.4 denote an alkyl, alkenyl, aralkyl or aryl group, X.sub.1, X.sub.2, Y.sub.1 and Y.sub.2 stand for an oxygen or a sulfur atom, and --Z.sub.1 -- and --Z.sub.2 -- are a specific aromatic group. Also provided are phenol compounds represented by the following formula: ##STR2## wherein R.sub.1, R.sub.2, X.sub.1 and Y.sub.1 have the same meanings as defined above; R.sub.5 and R.sub.6 are a hydrogen or halogen atom or an alkyl, alkoxy, aralkyl, aryl or hydroxyl group; p and q stand for an integer of 1-4; R.sub.5 and R.sub.6 may be either the same or different when p and q represent an integer of 2 or greater; and --Z.sub.3 -- means a specific divalent group.

Abstract: Disclosed are a crystal and crystalline solvate of a fluoran compound represented by the formula ##STR1## wherein R.sub.1 is ##STR2## and which are useful as chromogenic compounds in recording materials such as pressure-sensitive and heat-sensitive recording materials, a process for preparation of said crystal and said crystalline solvate, and recording materials comprising said crystal or said crystalline solvate.

Abstract: Disclosed are a crystal of a fluoran compound having the formula (I) comprising exhibiting high peaks at diffraction angles (2.theta.) of 7.5.degree. and 17.0.degree. and relatively high peaks at diffraction angles (2.theta.) of 15.1.degree., 19.1.degree., 21.5.degree. and 25.3.degree. in an X-ray diffraction diagram by the Cu-K.alpha. beam and a crystal of a fluoran compound having the formula (II) comprising exhibiting high peaks at diffraction angles (2.theta.) of 5.5.degree. and 19.2.degree. in an X-ray diffraction diagram by the Cu-K.alpha. beam, which is useful as a color forming compound in recording materials.

Abstract: Disclosed are novel crystal of the fluoran compound represented by the formula ##STR1## , characterized by a specific X-ray diffraction diagram; preparation process thereof; and recording materials comprising the crystal.