| 摘要 |
An optically readable media and packaging therefor, where the media includes a material that over time undergoes at least one of a chemical change or a physical change to render unreadable the optically readable media. The media is sealed within the packaging with a source of a chemical compound that inhibits the change, and the media is also sealed within the packaging with a getter of the chemical compound that over time absorbs said chemical compound, or which a substance that over time renders unreactive a reactive chemical compound. In a further embodiment the media is sealed within the packaging with a getter of a chemical compound that promotes the change. In this case the getter absorbs the chemical compound until saturated with the chemical compound, after which the concentration of the chemical compound until saturated with the chemical compound, after which the concentration of the chemical compound increases until the media is rendered unreadable. As non-limiting examples, the chemical compound may be NMP, DMF, acetone, or HCl. In another embodiment the media further includes a diffusion barrier that inhibits but does not prevent the chemical compound from reaching a layer of the media that over time undergoes at least one of a chemical change or a physical change to render unreadable the optically readable media, while in another embodiment the source of the chemical compound includes the diffusion barrier. In a further embodiment the media includes a first layer that over time undergoes the at least one of a chemical change or a physical change, a second layer that contains the source of a chemical compound that promotes the change, and the diffusion barrier is interposed between the first layer and the second layer.
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