Thermochromic Latent‐Pigment‐Based Time–Temperature Indicators for Perishable Goods

The development of cheap and reliable time–temperature indicators (TTIs) can greatly improve customer satisfaction with respect to the correct handling and storage of perishable goods. A series of new irreversible thermochromic squaraine dyes enables the preparation of simple TTIs whose time–temperature regime can be controlled by selection of the appropriate molecule/substrate combinations.