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:
Apr. 12, 1988
Filed:
Oct. 09, 1985
Himangshu R Bhattacharjee, Randolph, NJ (US);
James T Yardley, Morristown, NJ (US);
Thaddeus Prusik, Roosevelt, NJ (US);
Ronald R Chance, Morris Plains, NJ (US);
LifeLines Technology, Inc., Morris Plains, NJ (US);
Abstract
A photoactivated time-temperature indicator is based on diacetylenic salts. A thermally unreactive ('inactive') diacetylenic salt (or a mixture of such salts) is mixed, in a polymeric matrix, with a material that generates acid upon exposure to light. Photoexcitation, preferably by UV or near UV light, causes the formation of a thermal reactive ('active') free diacetylenic acid. Following this activation step, a progressive color development occurs at a rate that increases with temperature. The indicator is useful for monitoring the freshness of perishable products, particularly those that require refrigeration.