Abstract: A heat-sensitive recording material comprising a substrate and a heat-sensitive recording layer, the heat-sensitive recording layer containing a leuco dye, a developer, and a copolymer resin emulsion, the copolymer resin emulsion comprising a copolymer resin, the copolymer resin (1) containing (i) (meth)acrylonitrile, and (ii) one or more vinyl monomers copolymerizable with (meth)acrylonitrile, and (2) having a solubility parameter of 12.0 or higher, above mentioned vinyl monomers (ii) include at least a carboxyl group-containing vinyl monomer, and said at least a carboxyl group-containing vinyl monomer is 1 to 10 mass % of the total mass of the copolymer resin.

Abstract: The present invention relates to a heat-sensitive recording material having a high recording sensitivity, which is capable of providing excellent image quality even when recording is carried out at low energy, and causes reduced coating defects. The invention provides a heat-sensitive recording material obtained by forming, on a paper support, an undercoat layer and then a heat-sensitive recording layer, characterized in that: 1) the undercoat layer has at least two undercoat layers including a first undercoat layer and a second undercoat layer; and 2) the heat-sensitive recording layer has a thickness standard deviation of 0.30 or less, and also provides a method for producing the heat-sensitive recording material.

Abstract: A heat-sensitive recording material comprising a substrate and a heat-sensitive recording layer, the heat-sensitive recording layer containing a leuco dye, a developer, and a copolymer resin emulsion, the copolymer resin emulsion comprising a copolymer resin, the copolymer resin (1) containing (i) (meth)acrylonitrile, and (ii) one or more vinyl monomers copolymerizable with (meth)acrylonitrile, and (2) having a solubility parameter of 12.0 or higher, above mentioned vinyl monomers (ii) include at least a carboxyl group-containing vinyl monomer, and said at least a carboxyl group-containing vinyl monomer is 1 to 10 mass % of the total mass of the copolymer resin.

Abstract: The present invention relates to a heat-sensitive recording material having a high recording sensitivity, which is capable of providing excellent image quality even when recording is carried out at low energy, and causes reduced coating defects. The invention provides a heat-sensitive recording material obtained by forming, on a paper support, an undercoat layer and then a heat-sensitive recording layer, characterized in that: 1) the undercoat layer has at least two undercoat layers including a first undercoat layer and a second undercoat layer; and 2) the heat-sensitive recording layer has a thickness standard deviation of 0.30 or less, and also provides a method for producing the heat-sensitive recording material.