Development of a practical visual indicator tape for adhesive and coating analysis

A ninhydrin-coated, pressure-sensitive adhesive tape has been developed for the purpose of detecting specific chemical substances in various materials. Ninhydrin undergoes a visible color change in the presence of amines, isocyanates, and other chemical compounds. The tape was prepared by dissolving ninhydrin and applying it to an adhesive tape with an airbrush. The tape was allowed to dry and then applied to the surface of various cured and uncured materials to test for reactivity. It was then used successfully to detect unreacted components present in uncured or partially cured epoxy adhesives and coatings.