Abstract: There is provided a brightening ink composition for printing intended for realizing a heat insulating foamed paper container produced by foaming a low-melting point film by a heat treatment, such as a heat insulating foamed paper cup, the brightening ink composition conforming to the foaming without the occurrence of ink splits (cracks) upon foaming, having very small differences in level between the brightening printed areas and other printed areas at the container surface after foaming, making the container surface almost smooth, and having excellent design applicability and aesthetic properties as well as excellent heat resistance and print quality. A brightening ink composition containing a brightening material that imparts a sense of brightness, silicon dioxide, a binder resin and a solvent is prepared, and the brightening ink composition is used to form a printed layer of a paper container material for producing a heat insulating foamed paper container.

Abstract: An ink composition having a colorant; a binder resin; and a solvent; wherein the elongation ratio of the binder resin is 400% to 3,000%; wherein the binder resin comprises a urethane resin and a vinyl chloride/vinyl acetate copolymer, and the mixing ratio of the urethane resin:vinyl chloride/vinyl acetate copolymer relative to the total weight of the urethane resin and the vinyl chloride/vinyl acetate copolymer is 50:50 to 99:1; and wherein the urethane resin comprises a urethane-urea resin that is obtained by a process comprising reacting dibutylamine and a urethane prepolymer obtained by a process comprising reacting a polymeric polyol component having a number average molecular weight of 500 to 10,000 and an organic diisocyanate component having terminal isocyanate groups. A heat insulating foamed paper container material having at least one print pattern formed from said ink composition.

Abstract: There is provided a brightening ink composition for printing intended for realizing a heat insulating foamed paper container produced by foaming a low-melting point film by a heat treatment, such as a heat insulating foamed paper cup, the brightening ink composition conforming to the foaming without the occurrence of ink splits (cracks) upon foaming, having very small differences in level between the brightening printed areas and other printed areas at the container surface after foaming, making the container surface almost smooth, and having excellent design applicability and aesthetic properties as well as excellent heat resistance and print quality. A brightening ink composition containing a brightening material that imparts a sense of brightness, silicon dioxide, a binder resin and a solvent is prepared, and the brightening ink composition is used to form a printed layer of a paper container material for producing a heat insulating foamed paper container.

Abstract: There is provided a printing ink to be used in the production of a heat insulating foamed paper container obtained by heating a paper container which has a container body unit laminated with a high-melting point thermoplastic synthetic resin film on the inner surface and with a low-melting point thermoplastic synthetic resin film (low-Mp resin film) on the outer surface, and thereby foaming the low-Mp resin film, the printing ink being printed on the laminated low-Mp resin film upon the production of the paper container but inhibiting the occurrence of differences in level at the foamed surface of the low-Mp resin film. In an ink composition for printing on foamed paper containers, which contains a colorant, a binder resin and a solvent, a resin having an elongation ratio (elongation ratio as measured with a small-size tensile tester manufactured by Intesco Co., Ltd., under the conditions of a tensile speed of 100 mm/min and room temperature (25° C.)) of 400% to 3,000% is used as the binder resin.