Patent ID: 7524463
Filing Date: 2009-04-28
Classification: A01M,A61L,G01N,G04F

Abstract:
1. A substrate capable of dispensing a volatile air treatment chemical upon heating of the substrate in its configuration at a selected use temperature, the substrate comprising: said volatile air treatment chemical; a use indicator associated with the substrate and configured to automatically communicate an extent to which the air treatment chemical has been dispensed from the substrate as the substrate is heated at the selected use temperature, the use indicator comprising: wherein upon a first extent of heating of the substrate at the selected use temperature, a first of said two dyes can at least in part migrate to a first visible position and be visible; wherein upon a second extent of heating of the substrate at the selected use temperature after the first extent of heating a second of said two dyes can at least in part migrate to a second visible position that is the same or different from the first visible position so as to be visible; and wherein the extent to which the two dyes become visible in this manner is indicative of the extent to which the air treatment chemical has been dispensed from the substrate.