Patent ID: 8911861

Claim:
An assembly which comprises (1) a substrate which comprises a temperature-sensitive product, and (2) a temperature indicator which (a) comprises a first component comprising a side chain crystalline (SCC) polymer which (i) has a crystalline melting point, Tp, of 0-135° C., and (ii) is not cross-linked (b) undergoes a change in translucency, wherein the change first occurs at a temperature that is less than 5 degrees C. above Tp and wherein the change in the indicator remains when the temperature is reduced below Tp, wherein the SCC polymer is in the form of solid particles having a median particle size greater than 0.03μ and less than 10μ; and (c) comprises a second component, wherein the difference between the refractive index of the SCC polymer and the second component is greater at a temperature below Tp than at a temperature above Tp, wherein the second component comprises air voids or a matrix polymer.