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:
Oct. 29, 2002
Filed:
Jul. 02, 2001
Gordhanbhai N. Patel, Middlesex, NJ (US);
JP Labs, Inc., Middlesex, NJ (US);
Abstract
A device composed of (1) a color changing indicator, (2) an optional polymeric binder, preferably having gel forming capability, and (3) an activator solvent system which induces a color change in the indicator when device is frozen, in the region of about 0 to −30° C. An example of the device is an indicator of a fine dispersion of partially polymerized diacetylene of the formula: R—C═C—C═C—R, where R is a substituent group, e.g., 4BCMU where R=—(CH )OCONHCH COO(CH ) H, dispersed in a mixture of solvents, e.g., 96:4 water:ED (ethylene glycol diacetate), with or without a polymeric binder. When the temperature of the device is lowered to the freezing point of water, the activator solvent phase separates out of the mixture and induces a color change in the indicator. The device can undergo an irreversible color change, e.g., from blue to red, when the activator mixture is frozen in the region of about 0 to 30° C. The device made from the above system can be used as a freeze indicator for monitoring the undesirable freezing of materials, such as emulsions, latex paints, produce foods, flowers, sea foods, and vaccines which require freeze monitoring.