INDIKATOR, VERFAHREN ZU SEINER HERSTELLUNG SOWIE SEINE VERWENDUNG

摘要

The invention concerns an indicator for determining the variation over time of an event by reaction of a first chemical compound with a second chemical compound, which results in a visible colour change. The first chemical compound has a surfeit of electrons and the second chemical compound has a deficit of electrons. When the compounds are brought together simultaneously or consecutively, the course of an event is initiated. The invention also concerns further developments of this basic concept as well as a process for obtaining such an indicator, in which a solution of a compound with a surfeit of electrons is produced in a suitable solvent, if necessary in a solution of a substrate as a carrier, and at least one layer of the solution so obtained is applied to a preparation and then dried. A solution of a compound with a deficit of electrons is produced in a suitable solvent, if necessary in a solution of a substrate as a carrier, at least one layer of the solution so obtained is applied to the layer of the compound with a surfeit of electrons applied to the preparation and dried. This initiates the course of the event. The invention also concerns individual developments of this process and uses of such an indicator in products which exist for a limited time or can be kept for a limited time.