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:
Aug. 20, 2002
Filed:
Apr. 02, 2001
Applicant:
Inventors:
Jean Qiu, Andover, MA (US);
Joan M. Noyola, Maplewood, MN (US);
David J. Yarusso, Shoreview, MN (US);
Kevin R. Green, Maplewood, MN (US);
Assignee:
3M Innovative Properties Company, St. Paul, MN (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01K 3/00 ;
U.S. Cl.
CPC ...
G01K 3/00 ;
Abstract
A time-temperature indicator device provides a visually observable indication of the cumulative thermal exposure of an object. The device includes a substrate having a diffusely light-reflective porous matrix and a backing. The backing includes on its surface a viscoelastic indicator material for contacting the substrate and a barrier material for substantially inhibiting the lateral and longitudinal flow of viscoelastic indicator material between the substrate and the backing.