Time and temperature integrating indicator device
US6103351A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 1998 |
| Grant date | Aug 15, 2000 |
| Priority date | — |
| Expiry date | Mar 30, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24802
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Time and temperature integrating devices for providing a visually observable indication of cumulative thermal exposure are disclosed comprising (a) a substrate having thereon a thermally sensitive image-forming area comprising a combination of (i) an organic silver salt oxidizing agent and (ii) a reducing agent for the organic silver salt oxidizing agent, and (b) indicating indicia in association with the image forming area for indicating when the device has been exposed to a predetermined cumulative thermal exposure. In accordance with further embodiments of the invention, a process of applying such a device to a perishable product, and a perishable product having such a device applied directly thereto or to packaging thereof, are also disclosed. Time-temperature indicators in accordance with the invention undergo readily detectable changes can be easily optimized to match various rates of time-temperature dependent cumulative changes desired to be monitored for various products.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.