Tamper indicator tape
AssigneeMinnesota Mining and Manufacturing Company
InventorLew W. Cornell
Life of this patent
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Abstract
An easy opening, hermetically sealed container with a preformed aperture is covered by a tape closure having on its outer surface an indicator layer which changes color when flexed, thereby indicating whether the closure has been handled or tampered with.
Claims3
An adhesive tape having particular utility in preparing a sealed container comprising in combination a sheet backing material to one face of which is firmly adherently bonded a smooth, uniform coating of normally tacky and pressure-sensitive adhesive and to the other face of which is firmly adhesively bonded an indicator layer comprising a strong flexible binder matrix having a Young's modulus at 2% elongation of at least about 125,000 pounds per square inch, said binder containing dispersed throughout, a solid, color-forming substance and capsules containing a liquid dye precursor reactable with said color-forming substance.
Dependencies are inferred from the claim text.