US5053339A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color changing device for monitoring shelf-life of perishable products
Assignee: JP Laboratories Inc
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Filing: 1988-11-03
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Granted: 1991-10-01
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Expires: 2008-11-03
Abstract
Abstract A color changing device for monitoring the time-temperature storage history, i.e. shelf life, of perishable products. The device is constructed of an activator tape, containing an activator composition matrix, an indicating tape, containing an indicating composition matrix and an optional barrier matrix between the activator tape and the indicating tape. At least one matrix is a pressure sensitive adhesive. The activating composition, e.g. an organic acid such as citric acid, diffuses through the barrier and/or indicating matrix to continuously contact the indicating composition, e.g. an acid-base dye indicator such as 2,2',4,4',4",-pentamethoxy triphenylmethanol, to produce a visually observable color change at the temperature being monitored. The color intensifies with time and temperature, as more activator composition diffuses into the indicating matrix. The matrices are water-impermeable and the device preferably possesses activation energy and rate constant values for the color change which are substantially the same as those for product decay. This allows accurate and continuously observable monitoring of the abailable shelf-life of the perishable product to which the device is adhered to.
Inventors
- 👤 Gordhanbhai Patel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:23
CPC Classifications
G; G01; G01K; G01K3/00; G01K3/02; G01K3/04; G01N; G01N31/00; G01N31/22; G01N31/229
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
165 words
A device for measuring the shelf life of a perishable product having a measurable activativation energy of product deterioration comprising: a) an indicator tape comprised of a transparent polymer film and affixed thereto at least one matrix layer containing an indicator composition: b) an activator tape comprised of a substrate and affixed thereto at least one matrix layer containing an activator composition: c) a composite matrix, comprised of said indicator tape and activator tape matrix layers, bonded together by at least one water-impermeable pressure sensitive adhesive, said activator composition being capable of diffusing through said composite matrix in a predetermined time to contact and chemically react with said indicator composition producing a visually observable color change in said indicator composition, said device being substantially impermeable to moisture, and said device possessing an activation energy and rate constant for color change which are substantially the same as the activation energy and rate constant for product deterioration of the perishable product in the temperature region of monitoring.
Claim 2
Independent Claim
165 words
A device for measuring the shelf life of a perishable product having a measurable activativation energy of product deterioration comprising: a) an indicator tape comprised of a transparent polymer film and affixed thereto at least one matrix layer containing an indicator composition: b) an activator tape comprised of a substrate and affixed thereto at least one matrix layer containing an activator composition: c) a composite matrix, comprised of said indicator tape and activator tape matrix layers, bonded together by at least one water-impermeable pressure sensitive adhesive, said activator composition being capable of diffusing through said composite matrix in a predetermined time to contact and chemically react with said indicator composition producing a visually observable color change in said indicator composition, said device being substantially impermeable to moisture, and said device possessing an activation energy and rate constant for color change which are substantially the same as the activation energy and rate constant for product deterioration of the perishable product in the temperature region of monitoring.
Claim 3
Dependent Claim
30 words
The device of claim 1 wherein said composite matrix further comprises at least one barrier matrix layer permeable to said activator composition, laminated to said activator and indicator matrix layers.
Claim 4
Dependent Claim
22 words
The device of claim 1 wherein said polymer film is comprised of polyethylene, polypropylene, polyester, polyurethane, polyamide, polyvinylchloride, polycarbonate or cellulose acetate.
Claim 5
Dependent Claim
18 words
The device of claim 1 wherein said substrate is a translucent or opaque polymer film or metal foil.
Claim 6
Dependent Claim
35 words
The device of claim 1 wherein said indicator, activator or barrier matrix is independently a resin of the type: epoxy, phenol-formaldehyde, amino-formaldehyde, polyamide, vinyl, acrylic, polyurethane, polyester, alkyd, synthetic elastomer rosin, or pressure sensitive adhesive.
Claim 7
Dependent Claim
18 words
The device of claim 1 wherein said activator is an oxidizing agent and said indicator is redox dye.
Claim 8
Dependent Claim
19 words
The device of claim 1 wherein said activator is a reducing agent and said indicator is a redox dye.
Claim 9
Dependent Claim
20 words
The device of claim 1 wherein said activator is a base and said indicator is a base sensitive pH dye.
Claim 10
Dependent Claim
20 words
The device of claim 1 wherein said activator is an acid and said indicator is an acid sensitive pH dye.
Claim 11
Dependent Claim
19 words
The device of claim 9 where in said activator is citric acid and said indicator dye is 2,2',4,4',4"-pentamethoxy triphenylmethanol.
Claim 12
Dependent Claim
44 words
The device of claim 1 wherein: a.) the indicator tape comprises: a polyester film, a synthetic elastomer matrix containing 2,2',4,4',4"-pentamethoxy triphenylmethanol; b.) the activator tape comprises: a polyester film, the same synthetic elastomer as in (a) and containing and citric acid in solid solution.
Claim 13
Dependent Claim
17 words
The device of claim 1 wherein said indicator composition is displayed as at least one alphanumeric figure.
Claim 14
Dependent Claim
17 words
The device of claim 1 wherein said indicator composition is displayed as at least one bar code.
Claim 15
Dependent Claim
30 words
A process for monitoring the time-temperature storage history of a perishable product comprising the step of affixing to said product the device according to claim 1, and activating the device.
Claim 16
Dependent Claim
12 words
The process of claim 14 wherein the activating is by thermal annealing.
Claim 17
Dependent Claim
11 words
The process of claim 14 wherein the activating is by radiation.
Claim 18
Dependent Claim
12 words
The process of claim 14 wherein the activating is by applying pressure.
Claim 19
Dependent Claim
14 words
A perishable product having the device of claim 1, in activated form, attached thereto.
References Cited (Backward Citations)
US2614430A
Cited
US2889799A
Cited
US3065883A
Cited
US3078182A
Cited
US3311084A
Cited
US3360338A
Cited
US3386807A
Cited
US3414415A
Cited
US3479877A
Cited
US3520124A
Cited
US3677088A
Cited
US3954011A
Cited
US3942467A
Cited
US3946611A
Cited
US4042336A
Cited
US3981683A
Cited
US3981683B1
Cited
US3967579A
Cited
US3999946A
Cited
GB1521653A
Cited
US4057020A
Cited
US4154107A
Cited
US4163427A
Cited
US4212153A
Cited
US4188437A
Cited
US4195056A
Cited
US4195058A
Cited
US4292916A
Cited
US4280441A
Cited
US4432656A
Cited
US4382700A
Cited
US4410493A
Cited
US4509449A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-09-30 | 1995-04-01 | 1995-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-09-30 | 1999-04-01 | 1999-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-09-30 | 2003-04-01 | 2003-10-01 | $7700.00 | Window Closed / Lapsed |