Patent ID: 9555147
Date: 2017-01-31
CPC Classifications: A61F,A61L,C09B

Claim:
1. A color-changing article comprising: a substrate; and a film disposed on a surface of the substrate, the film comprising a dried colorless or pale, non-aqueous based, homogeneous solution located in a water-pervious, organic polymeric cage comprising at least one polymer soluble in volatile organic solvents; wherein the solution comprises a) one or more leuco dyes; b) one or more separators that are non-volatile and soluble in both volatile organic solvents and water; and c) one or more electron withdrawing color-developers that cannot form colored complexes with said leuco dyes in the presence of said separators without the presence of water, but can form colored complexes with the leuco dyes in the presence of water; wherein the film manifests a color when contacted by an aqueous medium.