Time-temperature indicating device

A time-temperature indicator device comprising at least one active reactant being at least a part of an electrical component, said at least one active reactant is selected such that it intrinsically changes at least an electrical property of said electrical component at a rate that is time-temperature dependent.

A method of time temperature indication comprising the step of causing a chemical and/or physical reaction between at least one active reactant and at least one passive reactant in the form of a viscous substance effecting a change in at least an electrical property of an electrical component wherein said at least one active reactant is at least a part of a component that is configured to be either an electrical component or transformable into an electrical component and wherein said at least one passive reactant is selected such that, when being exposed to a temperature higher than a certain temperature specific for said at least one passive reactant, thereby causing time-temperature dependent development of said chemical and/or physical reaction.

A printing ink or printing ink concentrate, comprising an active reactant that intrinsically changes at least an electrical property of an electrical component at a rate that is time-temperature dependent, a passive reactant affectable by a chemical and/or physical reaction with an active reactant, wherein the passive reactant causes time-temperature dependent development of said chemical and/or physical reaction that intrinsically changes at least an electrical property of an electrical component and/or a passive reactant that causes time dependent transfer of heat towards another passive reactant thereby causing time-temperature dependent development of a chemical and/or physical reaction between the other passive reactant and an active reactant that intrinsically changes at least an electrical property of an electrical component.