Time-temperature indicator system i

Time-temperature indicator system, comprising at least one reactive agent and at least one mobile agent;

• said reactive agent(s) being contained in a first compartment adjacent to a separate second compartment containing the mobile agent(s);
• said first and second compartments initially being separated by suitable means for preventing contact between the mobile agent(s) and the reactive agent(s);
• the system being activated by bringing said two compartments into contact and thereby allow for the mobile agent(s) to migrate through a matrix contained in the first compartment;
• said matrix contained in the first compartment comprising a mixture of at least a first and a second matrix component;
• said first matrix component being a gel-forming polymer having a melting point below 90° C.;
• and said second matrix component being either i) a reversible gel-forming polymer having a melting point that is at least 5° C. higher than the melting point of said first matrix component or ii) an irreversible gel-forming polymer;
• wherein at least one of said reactive agent(s) is contained within the matrix contained in the first compartment and/or at least one of said matrix components contained in the first compartment is at least one of the reactive agent(s).