| abstract |
In accordance with the present invention, an irreversible tamper evident system for a button closure is provided. The irreversible tamper evident system is provided by a color change system carried by the flexible button portion of the closure. The color change system comprises an indicator coating over a dark colored substrate coating. The indicator coat is preferably colored with a light colored transparent colorant such as an orange colored fluorescent dye. The indicator coat is preferably a liquid material which can be cured by evaporation, heat, UV irradiation or the like, to form a solid layer. When the substrate layer and indicator layer are in intimate contact, a first color is observed. Depending upon the relative colors used for this substrate and indicator layers, this first color can be a combination of the colors of the two layer or can be primarily the color of the substrate layer. However, when the layers become separated and the outer layer is spaced from the inner layer, a second color is observed which second color is primarily the color of the indicator coat. |