US3888631A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature indicator
Assignee: Individual
•
Filing: 1974-04-08
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Granted: 1975-06-10
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Expires: 1994-04-08
Abstract
Abstract A temperature indicator or monitor for deep frozen products, comprising paper-like fibrous material containing a binder and two water soluble colorless reagents. At least one of the reagents is encapsulated in microcapsules in the form of an aqueous solution which is still liquidous below 0*C, and wherein such reagent upon rupture of the capsules, which occurs at a temperature range in the order of 4*C to 0*C, combines with the other reagent to form a dye which permeates the fibers of the paper-like fibrous material and contrasts with its basic color.
Inventors
- 👤 Oskar Edwin Sturzinger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:28
CPC Classifications
G; G01; G01K; G01K11/00; G01K11/12; G01K3/00
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
139 words
A TEMPERATURE INDICATOR FOR DEEP FROZEN PRODUCTS COMPRISING A PAPER-LIKE FIBROUS MATERIAL CONTAINING A BINDER AND TWO WATER SOLUBLE COLORLESS REAGENTS WHICH REACT CHEMICALLY WHEN BOTH REAGENTS ARE LIQUID TO PRODUCE A DYE WHICH IMBUES THE FIBERS WITH A COLOR WHICH CONTRASTS WITH THE BASIC COLOR OF THE FIBROUS MATERIAL, AT LEAST ONE OF THE REAGENTS BEING PRESENT IN THE FORM OF A MICROENCAPSULATED AQUEOUS SOLUTION THEREOF, THE SOLUTION BEING IN THE LIQUID STATE AT A TEMPERATURE BELOW 0*C. AND HAVING A PREDETERMINED SUB-ZERO FREEZING POINT, THE MICROCAPSULES ADAPTED TO BURST AT A TEMPERATURE OF 4*C. TO 0*C. AS A RESULT OF THE VOLUME EXPANSION OF THE WATER IN THE AQUEOUS SOLUTION AND PERMIT THE REAGENTS TO REACT TO PRODUCE THE DYE UNTIL THE TEMPERATURE HAS BEEN LOWERED TO A POINT WHERE AT LEAST ONE OF THE REAGENTS FREEZE.
Claim 2
Dependent Claim
139 words
A TEMPERATURE INDICATOR FOR DEEP FROZEN PRODUCTS COMPRISING A PAPER-LIKE FIBROUS MATERIAL CONTAINING A BINDER AND TWO WATER SOLUBLE COLORLESS REAGENTS WHICH REACT CHEMICALLY WHEN BOTH REAGENTS ARE LIQUID TO PRODUCE A DYE WHICH IMBUES THE FIBERS WITH A COLOR WHICH CONTRASTS WITH THE BASIC COLOR OF THE FIBROUS MATERIAL, AT LEAST ONE OF THE REAGENTS BEING PRESENT IN THE FORM OF A MICROENCAPSULATED AQUEOUS SOLUTION THEREOF, THE SOLUTION BEING IN THE LIQUID STATE AT A TEMPERATURE BELOW 0*C. AND HAVING A PREDETERMINED SUB-ZERO FREEZING POINT, THE MICROCAPSULES ADAPTED TO BURST AT A TEMPERATURE OF 4*C. TO 0*C. AS A RESULT OF THE VOLUME EXPANSION OF THE WATER IN THE AQUEOUS SOLUTION AND PERMIT THE REAGENTS TO REACT TO PRODUCE THE DYE UNTIL THE TEMPERATURE HAS BEEN LOWERED TO A POINT WHERE AT LEAST ONE OF THE REAGENTS FREEZE.
Claim 3
Dependent Claim
29 words
The temperature indicator as defined in claim 1, wherein the aqueous solution freezes at a temperature of about -18*C, so that the chemical reaction is stopped at such temperature.
Claim 4
Dependent Claim
15 words
The temperature indicator as defined in claim 1, wherein both reagents are contained in microcapsules.
References Cited (Backward Citations)
US3695903A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-09 | 1978-12-09 | 1979-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-09 | 1982-12-09 | 1983-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-09 | 1986-12-09 | 1987-06-10 | $7700.00 | Window Closed / Lapsed |