Temperature-activated time-temperature indicator
US8671871B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 21, 2011 |
| Grant date | Mar 18, 2014 |
| Priority date | — |
| Expiry date | Aug 13, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01K11/06
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A temperature-activatable time-temperature indicator that can be used to monitor the historical exposure of a host product to ambient temperatures includes an optically readable, thermally sensitive indicator element. The indicator element can be inactive below a base temperature and is intrinsically thermally responsive at or above an activation temperature which is equal to or greater than the base temperature. The indicator can record cumulative ambient temperature exposure above the activation temperature irreversibly with respect to time. The indicator element can include a synthetic polymeric material, and optionally, a dye. A side-chain crystallizable polymer such as poly(hexadecylmethacrylate), that is solid below the base temperature and is a viscous liquid above the activation temperature can be employed. Intense indicator element colors can be obtained using an appropriate dye or dyes. Various structural configurations of indicator are described and illustrated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.