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:
Jan. 03, 2012
Filed:
Dec. 03, 2007
Wei-fang Su, Taipei, TW;
Yulia Galagan, Taipei, TW;
Sheng-hao Hsu, Taipei, TW;
Other;
Sun Own Industrial Co. Ltd., Chang Hua Hsien, TW;
Abstract
The present invention discloses an apparatus for indicating the passage of time, comprising a substrate and an indicating layer formed on the substrate. The indicating layer comprises a polymer matrix and a predetermined amount of redox compound under the reduced form. The redox compound is dispersed in the polymer matrix and has the following properties: the reduced form of the redox compound reacts with oxygen to form the oxidized form of the redox compound; the hue or color density of the reduced form of the redox compound is different from that of the oxidized form of the redox compound; and the hue or color density of the indicating layer varies as the time for the reduced form of the redox compound contacting with oxygen in environment increases to have the amount of the oxidized form of the redox compound increase so as to indicate the passage of time.