Thermally-activated time-temperature indicator
CA 1185157 A · Owner: Minnesota Mining And Manufacturing Company · Inventors: Arens, Robert P.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
15-, Abstract, Device which visually indicates exposure to a temperature within a predetermined range for a predetermined length of time. The device may be used in the fast food industry to make certain that all food sold has been recently prepared. An opaque microporous sheet has a colored stratum on the back and a transparent fusible coating on the face. The coating is a solid solution of amorphous rubbery polymer in crystallizable solvent which upon melting, gradually penetrates and transparentizes the microporous layer, rendering the colored stratum visible.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted April 9, 1985. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 9, 2002.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.