Abstract: Disclosed is a heat-sensitive recording material having excellent properties such as high color-forming sensitivity (excellent thermal response), a high formed color density, freedom from ground fogging and excellent retainability of recorded image. The heat-sensitive recording material has a heat-sensitive recording layer containing (1) at least two diphenylsulfone derivatives, (2) a combination of a diphenylsulfone derivative with a hydroxybenzoic acid derivative, (3) a combination of a diphenylsulfone derivative with a diphenyl ether derivative, (4) a combination of a diphenylsulfone derivative with salicylamide or a derivative thereof, or (5) a combination of 4,4?-dihydroxydiphenylsulfone, salicylanilide and dibenzyloxalate.

Abstract: Disclosed is a heat-sensitive recording material having excellent properties such as high color-forming sensitivity (excellent thermal response), a high formed color density, freedom from ground fogging and excellent retainability of recorded image. The heat-sensitive recording material has a heat-sensitive recording layer containing (1) at least two diphenylsulfone derivatives, (2) a combination of a diphenylsulfone derivative with a hydroxybenzoic acid derivative, (3) a combination of a diphenylsulfone derivative with a diphenyl ether derivative, (4) a combination of a diphenylsulfone derivative with salicylamide or a derivative thereof, or (5) a combination of 4,4′-dihydroxydiphenylsulfone, salicylanilide and dibenzyloxalate.

Abstract: The present invention provides a heat-sensitive recording material high in sensitivity and whiteness. That is, a heat-sensitive recording material which comprises a support and a recording layer between which an intermediate layer is provided and which is of high sensitivity could be obtained by using a latex having a temperature-sensitive gelling characteristic as a binder of the intermediate layer and by adjusting pH of a coating solution of the intermediate layer to 7.0 or more, and adjusting temperature of the coating solution at the time of preparation and coating to a temperature lower at least 20.degree. C. than the gelling temperature of the temperature-sensitive latex. Furthermore, a heat-sensitive recording material of high whiteness and very high printability could be obtained by adding a non-crosslinking type acrylic alkali thickening agent to the coating solution of the intermediate layer.