Heated volatile dispensing device with dye-based use-up indicator
AssigneeS.C. Johnson & Son, Inc.
InventorsJoel Adair, Brian Davis, Gopal Ananth, Padma Varanasi
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Abstract
Heated volatile dispensers are disclosed that are provided with automated dye-based use-up indicators. Multiple migrate able dyes of different colors are positioned adjacent a porous substrate. Heating of the substrate, such as a slab impregnated with an insect repellent, both causes the impregnated chemical to dispense from the slab and the indicator dyes to migrate to one or more visible positions. One dye migrates to a visible position faster than a dye of a different color. Further heating may cause one or both dyes to change color at a visible position. The dye movement imparts information about the degree of use-up of the impregnating chemical.
Claims21
A substrate capable of dispensing a volatile air treatment chemical upon heating of the substrate, the substrate comprising:
- 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, the use indicator comprising:
- at least two dyes each having an at least somewhat different color from the other;
- and
- a covering configured to restrict migration of the dyes prior to heating of the covering, and to permit migration of the dyes while the substrate is being heated;
- wherein upon a first extent of heating of the substrate, a first of said two dyes can at least in part migrate to a first visible position;
- wherein upon a second extent of heating of the substrate 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;
- 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.
A device for dispensing an air treatment chemical into a surrounding air environment in response to heating of a substrate, the device comprising:
- a porous substrate to which has been applied the air treatment chemical;
- at least two dyes positioned in, against, or adjacent the substrate;
- and
- means for controlling migration of the at least two dyes such that migration of the at least two dyes prior to said heating is restricted, and migration of said at least two dyes to a visible surface after such heating can occur.
A method of producing an air treatment device having an automatic use-up indicator, the method comprising:
- covering two migrate able dyes having differing color adjacent a porous substrate;
- and
- impregnating the substrate with an air treatment chemical.
A use indicator configured to automatically communicate the extent to which the use indicator has been exposed to a selected use temperature, the use indicator comprising:
- at least two dyes, each having an at least somewhat different color from the other;
- and
- a covering configured to restrict migration of the dyes prior to heating of the covering to the use temperature, and to permit migration of the dyes while heated to the use temperature;
- wherein, upon a first extent of heating of the use indicator, a first of said two dyes can at least in part migrate to a first visible position;
- wherein, upon a second extent of heating of the use indicator 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;
- and
- wherein an extent to which the two dyes become visible in this manner is indicative of total exposure of the use indicator to the use temperature.
Dependencies are inferred from the claim text.