Abstract: The present invention provides a heat-sensitive recording material that comprises a support, a heat-sensitive recording layer comprising a leuco dye and a developer, and a protective layer principally comprising a pigment and a binder. The support, the heat-sensitive recording layer, and the protective layer are provided in this order. The protective layer comprises: (1) a pigment of secondary particles with an average particle diameter of 30 to 900 nm formed by aggregation of amorphous silica primary particles with a particle diameter of 3 to 70 nm; or (2) a pigment of secondary particles with an average particle diameter of 30 to 900 nm formed by aggregation of amorphous silica primary particles with a particle diameter of 3 to 70 nm, and a binder comprising acetoacetyl modified polyvinyl alcohol with a saponification degree of 90 to 100 mol % and a polymerization degree of 1900 to 5000.

Abstract: A heat-sensitive recording material has a support, and a heat-sensitive recording layer including at least a leuco dye, a developer and a binder. The heat-sensitive recording layer contains secondary particles with an average particle diameter of 30 to 900 nm formed by aggregation of primary particles of amorphous silica with a particle diameter of at least 3 nm and less than 30 nm, and optionally a basic pigment. A protective layer may be formed on the heat-sensitive recording layer.

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: The present invention provides a heat-sensitive recording material that comprises a support, a heat-sensitive recording layer comprising a leuco dye and a developer, and a protective layer principally comprising a pigment and a binder. The support, the heat-sensitive recording layer, and the protective layer are provided in this order. The protective layer comprises: (1) a pigment of secondary particles with an average particle diameter of 30 to 900 nm formed by aggregation of amorphous silica primary particles with a particle diameter of 3 to 70 nm; or (2) a pigment of secondary particles with an average particle diameter of 30 to 900 nm formed by aggregation of amorphous silica primary particles with a particle diameter of 3 to 70 nm, and a binder comprising acetoacetyl modified polyvinyl alcohol with a saponification degree of 90 to 100 mol % and a polymerization degree of 1900 to 5000.

Abstract: A heat-sensitive recording material has a support, and a heat-sensitive recording layer including at least a leuco dye, a developer and a binder. The heat-sensitive recording layer contains secondary particles with an average particle diameter of 30 to 900 nm formed by aggregation of primary particles of amorphous silica with a particle diameter of at least 3 nm and less than 30 nm, and optionally a basic pigment. A protective layer may be formed on the heat-sensitive recording layer.

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.