Patent US4006116A successfully refreshed from Google Patents.
US4042336A
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Time temperature integrating indicator
Assignee: Pymah Corp
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Filing: 1975-09-22
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Granted: 1977-08-16
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Expires: 1995-09-22
Abstract
Abstract The temperature history of a product is visually displayed as a color front on an indicator, the distance of front advancement being a function of the temperature time integral. The indicator measures the gas generation in a first compartment by a wick in a second compartment, the wick also being in communication with the first compartment. Optionally, a gas permeable film separates the gas generating material and the wick. The indicator is fine tuned for time temperature integral by incorporating into the wick a quantifier with which the gas generated reacts preferentially.
Inventors
- 👤 Raymond P. Larsson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:04
CPC Classifications
G; G01; G01K; G01K3/00; G01K3/02; G01K3/04
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
172 words
A temperature time integrating indicator device which comprises: a. an elongated envelope having generally co-extensive upper and lower walls each of a gas impermeable material, the walls being sealed together in a continuous course extending about the periphery of each, a first longitudinal portion of said envelope comprising a gas generation section within said envelope and a second longitudinal portion of said envelope comprising an indicating section within said envelope; b. a gas generating material disposed in the gas generation section of said envelope; c. an elongated wick disposed longitudinally of the envelope with one end thereof in said gas generation section, said wick extending a distance along said envelope indicating section and the other end thereof being remote from said gas generating section; d. a rate controlling film separating said wick from the gas generating material; e. an indicator composition deposited on said wick, said indicator composition producing a color change in the presence of gas generated by said gas generating material; and f. a quantifier incorporated into the indicator composition.
Claim 2
Dependent Claim
172 words
A temperature time integrating indicator device which comprises: a. an elongated envelope having generally co-extensive upper and lower walls each of a gas impermeable material, the walls being sealed together in a continuous course extending about the periphery of each, a first longitudinal portion of said envelope comprising a gas generation section within said envelope and a second longitudinal portion of said envelope comprising an indicating section within said envelope; b. a gas generating material disposed in the gas generation section of said envelope; c. an elongated wick disposed longitudinally of the envelope with one end thereof in said gas generation section, said wick extending a distance along said envelope indicating section and the other end thereof being remote from said gas generating section; d. a rate controlling film separating said wick from the gas generating material; e. an indicator composition deposited on said wick, said indicator composition producing a color change in the presence of gas generated by said gas generating material; and f. a quantifier incorporated into the indicator composition.
Claim 3
Dependent Claim
31 words
The indicator of claim 1 wherein the gas generated is an acidic gas and the quantifier is a compound having a dissociation constant (pK b ) of about at least 7.
Claim 4
Dependent Claim
16 words
The indicator of claim 2 wherein the pK b of the compound is at least 8.
Claim 5
Dependent Claim
16 words
The indicator of claim 2 wherein the gas is a C 1 -C 6 carboxylic acid.
Claim 6
Dependent Claim
25 words
The indicator of claim 4 wherein the gas generated is acetic acid and the quantifier is sodium hydroxide, sodium carbonate, quinine or Tris (hydroxymethyl) aminomethane.
Claim 7
Dependent Claim
17 words
The indicator of claim 5 wherein the pH sensitive dye is methyl orange, methyl red, cresol red.
Claim 8
Dependent Claim
31 words
The indicator of claim 1 wherein the gas generated is a basic gas and the quantifier is a compound having a dissociation constant (pK a ) of about 7 or less.
Claim 9
Dependent Claim
23 words
The indicator of claim 7 wherein the gas is NH 3 and the quantifier is tartaric acid, potassium acid phosphate or cinnamic acid.
Claim 10
Dependent Claim
18 words
The indicator of claim 8 wherein the pH sensitive dye is phenol red, cresol red or ethyl red.
Claim 11
Dependent Claim
14 words
The indicator of claim 1 wherein a humectant is included in the indicator composition.
Claim 12
Dependent Claim
16 words
The indicator of claim 10 wherein the humectant is glycerol, ethylene glycol, propylene glycol or mannitol.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-15 | 1981-02-14 | 1981-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-15 | 1985-02-14 | 1985-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-15 | 1989-02-14 | 1989-08-16 | $7700.00 | Window Closed / Lapsed |