초록 ▼

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 re

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.

대표청구항 ▼

[ What is claimed is:] [1.] A time and temperature integrating device for providing a visually observable indication of cumulative thermal exposure comprising(a) a substrate having thereon an area comprising a thermally sensitive image-forming composition comprising a combination of (i) an organic s

[ What is claimed is:] [1.] A time and temperature integrating device for providing a visually observable indication of cumulative thermal exposure comprising(a) a substrate having thereon an area comprising a thermally sensitive image-forming composition comprising a combination of (i) an organic silver salt oxidizing agent and (ii) a reducing agent for the organic silver salt oxidizing agent, which image-forming composition exhibits a visual change in response to thermal exposures, the visual change being correlated to known levels of time and temperature integrated thermal exposure and(b) indicating indicia in association with the thermally sensitive area for indicating when the device has been exposed to a predetermined level of cumulative thermal exposure; rein the thermally sensitive image-forming composition comprises total silver metal coverage of from 0.1 to 10 g/m.sup.2.