Activatable time-temperature indicator
US4812053A · kind A · utility
117Cited by
15References
20Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Aug 7, 1987 |
| Grant date | Mar 14, 1989 |
| Priority date | — |
| Expiry date | Aug 7, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S428/913
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An activatable time-temperature indicator consists of an oxygen-sensitive reaction product of a triarylmethane dye and a decolorant that is coated on a substrate and covered by an oxygen barrier. Optinally, an oxygen-permeable layer is between the coating and the oxygen barrier. The indicator is activated by removing the oxygen barrier. Following this activation step, a progressive color development occurs at a rate that increases with temperature. The indicator is useful for monitoring the freshness of perishable products, particularly those stored at sub-ambient temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.