Heat-sensitive recording materials

Abstract

A heat-sensitive recording material includes a heat-sensitive recording layer on a support which layer produces a color upon heating, and a protective layer on the heat-sensitive recording layer. The protective layer is obtained from a composition (A) based on an emulsion of a copolymer resin (a). The copolymer resin (a) includes a vinyl monomer component having a carboxyl group, and a vinyl monomer component copolymerizable with the vinyl monomer component. The copolymer resin (a) contains 1 to 10 parts by weight of the vinyl monomer component having a carboxyl group. The copolymer resin has a SP value (solubility parameter) of not less than 9.5 (cal/cm3)1/2 and a glass transition temperature (Tg) of 20 to 130° C. The emulsion of the copolymer resin (a) has a minimum film-forming temperature (MFT) of more than 5° C. The emulsion for heat-sensitive recording material provides high durability, in particular water resistance, antiblocking properties in water-wetted state and chemical resistance, and has significantly improved storage stability.

Dependencies are inferred from the claim text.