US Patent 7836722 Containers and packagings for regulating heat transfer

A food container includes an upper wall, a lower wall, and a side wall extending between the upper wall and the lower wall. At least one of the upper wall, the lower wall, and the side wall includes a plurality of microcapsules containing a phase change material. The phase change material has a latent heat in the range of 40 J/g to 400 J/g and a transition temperature in the range of 0° C. to 100° C. The phase change material provides thermal regulation based on at least one of absorption and release of the latent heat at the transition temperature.