Abstract: A shade enhancing agent comprises an aqueous resin emulsion composition obtained by polymerizing a monomer in the presence of a cationic surfactant or a cationic protective colloid, polymerizing a monomer and adding a cationic protective colloid or polymerizing a monomer in the presence of a cationic or nonionic emulsifying dispersant so as to have a cationic group in the molecule, a dry film of said composition having a glass transition point (Tg) in the range between 20.degree. C. and 110.degree. C. and a refractive index of 1.50 or less, said emulsion composition having a zeta potential in the range between +5 and +80 mV at an ion strength of 10.sup.-3 and a pH value of 7.

Abstract: A thermosensitive recording member comprises (1) a substrate, (2) a foamed dispersion layer, provided on the substrate, in which an aqueous, self-emulsifiable resin having an I/O value of 0.6 to 1.1 has been dispersed, and (3) a thermosensitive coloring layer, provided on the foamed dispersion layer, containing an electron-donating dye and an electron-accepting compound to present a color by reacting with the dye, improved in sensitivity.

Abstract: Disclosed is a heat sensitive paper comprising;(a) a base paper,(b) a coating layer on said base paper formed from an acrylic aqueous dispersion containing particles having an average diameter of 0.001 to 0.05 microns prepared by the following steps;(i) polymerizing of a monomer having a salt-forming group and a polymerizable double bond and a copolymerizable monomer in a hydrophilic organic solvent,(ii) neutralizing the salt-forming group by adding a neutralizing agent to the polymer solution, and(iii) adding water to the polymer solution and distilling away the hydrophilic organic solvent, and(c) a heat sensitive color developing layer comprising a colorless or light color electron donative dye and an electron acceptant compound which reacts with said electron donative dye to develop color, on said coating layer.

Abstract: A thermosensitive recording medium comprises a substrate and a thermosensitive, coloring layer, provided on the substrate, comprising a binder, a colorless or light-colored electron-donating dye, an electron-accepting compound to react with the electron-donating dye and form a coloring matter and then an ester compound obtained from a fatty acid having 20 to 28 carbon atoms and a straight or cyclic alcohol, the ester having a melting point of 50 to 100 degree C. and one or more non-phenolic hydroxy group. It is improved in prevention from fogging and sensitivity.

Abstract: A color deepening agent comprises (a) an aqueous resin composition obtained by polymerizing a monomer having a polymerizable unsaturated bond, in the presence of a polyurethane emulsion having a thermosetting reactivity, the refractive index of a dry film of said aqueous resin composition being lower than 1.50, and (b) at least one compound selected from the group consisting of silicon compounds and fluorine compounds.