Patent ID: 7682830

Claim:
A product shelf life monitoring system comprising: a substrate having a substrate surface, the substrate surface having an occupied surface portion and an unoccupied surface portion contiguous with the occupied surface portion; an active indicator composition supported on the occupied surface portion, the unoccupied surface portion being free of active indicator composition, the active indicator composition being responsive with a visible change to incident thermal energy and to ultraviolet radiation, an associated product being susceptible to at least the thermal energy; and a layer of a visibly transparent, ultraviolet-blocker ink composition disposed between said indicator composition and the source of said incident ultraviolet radiation to intercept and ameliorate the effects of said incident ultraviolet radiation upon said indicator composition; wherein said ultraviolet-blocker ink composition layer is at least co-extensive with said active indicator composition and is situated entirely within said occupied surface portion of said substrate surface area and said unoccupied surface portion is not covered by the ultraviolet radiation-absorbent layer; wherein said active indicator composition comprises an indicator ink printed upon said substrate; wherein said ultraviolet-blocker ink composition is overprinted on said substrate over said indicator ink and comprises a lacquer base, 2-2′-dihydroxy-methoxybenzophenone, zinc oxide, and orasol yellow dye and a liquid vehicle.