| 摘要 |
A method and apparatus for manifesting the time-temperature history of a perishable object includes the providing the object with a substrate having layer that is comprised of a volatile component and at least one other component, where the volatile component has an evaporation rate related to time and temperature. The teachings herein include allowing the volatile component to evaporate, causing a color change with the remaining component that reflects a time-temperature history of the object. The other component may include a lactone dye or crystal violet lactone, The layer may include poly-p-(hydroxystyrene), ethanol, crystal violet lactone and N-methyl pyrrolidinone, or may include poly-p-(hydroxystyrene), ethanol, crystal violet lactone, ammonia, N-methyl pyrrolidinone, and formaldehyde. A barrier may be provided to control the removal of the volatile component, and at least one chromophore may be provided to bias the layer so as to reduce an amount of time required before the color change is detectable. A dispenser of color change labels is also disclosed, as is a method for applying labels to a perishable object to be monitored. |
