The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 15, 1980
Filed:
Feb. 07, 1978
Agis F Kydonieus, New York, NY (US);
Inja K Smith, West Orange, NJ (US);
Reid A Conroy, York, PA (US);
Ernest A Pedicano, Greenwich, CT (US);
Herculite Protective Fabrics Corporation, New York, NY (US);
Abstract
A laminated indicator which changes in a visually perceptible mode with the passage of time and a method for making such an indicator. At least two layers are provided whereby the molecular migration of an agent in an interior layer to the outermost surface of the exterior layer causes a change which can be visually percepted, e.g., a change in color or shade. Preferred embodiments include the migration of a dye or the migration of an acid or base wherein the outermost layer has the other member of an acid-base pair and a pH indicator.