US4057029A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Time-temperature indicator
Assignee: INFRATAB CORP
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Filing: 1976-03-08
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Granted: 1977-11-08
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Expires: 1996-03-08
Abstract
Abstract A time-temperature indicator having a time-temperature sensitive component including a layer of material which at temperatures above a predetermined transition temperature changes from an impermeable, psuedo-crystalline state to a permeable, liquid-crystalline state. A reactant material having a predetermined rate of diffusion through the layer at temperatures above its transition temperature is maintained out of contact with an indicator by the layer at temperatures below the transition temperature. A container for the time-temperature component includes a transparent face for viewing the time-temperature component. The container is adapted for attachment to an object, such as to the package of a time and temperature sensitive product to visually indicate the product has been exposed above a particular temperature far in excess of a certain period of time.
Inventors
- 👤 Charles Seiter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:34
CPC Classifications
G; G01; G01K; G01K11/00; G01K11/06; G01K3/00; G01K3/02; G01K3/04; Y; Y10; Y10S; Y10S428/00; Y10S428/913
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
100 words
A time-temperature indicating device comprising: a diffusion layer of a material having a first impermeable, crystalline-like state and a second permeable, liquid-crystalline state, said material being capable of transition between said first and said second states at a clearly defined temperature; an indicator disposed on one side of said diffusion layer; and a reactant material for said indicator normally maintained out of contact with said indicator by said diffusion layer, said reactant material having a predetermined rate of diffusion through said diffusion layer to contact and react with said indicator when said diffusion layer is in the permeable, liquid-crystalline state.
Claim 2
Dependent Claim
100 words
A time-temperature indicating device comprising: a diffusion layer of a material having a first impermeable, crystalline-like state and a second permeable, liquid-crystalline state, said material being capable of transition between said first and said second states at a clearly defined temperature; an indicator disposed on one side of said diffusion layer; and a reactant material for said indicator normally maintained out of contact with said indicator by said diffusion layer, said reactant material having a predetermined rate of diffusion through said diffusion layer to contact and react with said indicator when said diffusion layer is in the permeable, liquid-crystalline state.
Claim 3
Dependent Claim
34 words
The device of claim 1 further including container means for enclosing said diffusion layer, said indicator and said reactant material, at least a portion of said means being transparent for viewing the interior thereof.
Claim 4
Dependent Claim
69 words
The device of claim 1 wherein said diffusion layer comprises at least a molecular thickness film of a surface-active material comprising a mixture of an organic acid and an organic base, each having between 8 and 20 carbon atoms, the molecules of said film including a hydrophilic and a lipophilic group and being oriented with the long axis of the molecules substantially perpendicular to the plane of said film.
Claim 5
Dependent Claim
12 words
The device of claim 3 wherein said surface-active material is a phospholipid.
Claim 6
Dependent Claim
17 words
The device of claim 3 wherein said surface-active material comprises the salt of an alcohol-fatty acid ester.
Claim 7
Dependent Claim
42 words
The device of claim 1 wherein said diffusion layer material is selected from the group consisting of dioleoyl lecithin, egg yolk lecithin, 1 stearyl-2 oleoyl lecithin, soya lecithin, dimyristoyl lecithin, dipalmitoyl lecithin, phosphatidyl choline, phosphatidyl serine, decanol/sodium caprylate, and hexanol/cethylmethyl ammonium bromide.
Claim 8
Dependent Claim
29 words
The device of claim 1 wherein said reactant material is selected from the group consisting of lauryldiethylamine, decanoic acid, aniline, m-chloroaniline, guanidine, dodecanoic acid, propanoic acid and oleic acid.
Claim 9
Dependent Claim
29 words
The device of claim 1 wherein said reactant is selected from the group consisting of alizarin, bromcresol green, sodium indigo sulfonate, phenolphthalein, methyl violet, methyl orange and bromthymol blue.
Claim 10
Dependent Claim
14 words
The device of claim 1 wherein said reactant is dispersed in said diffusion layer.
Claim 11
Dependent Claim
99 words
A time-temperature indicating device for indicating deterioration of perishable goods and the like, said device comprising: a time-temperature sensitive component including a reactant material and an indicator responsive to contact by said reactant to produce a visible reaction, said reactant and indicator being normally separated by a diffusion layer having an impermeable, pseudo-crystalline state and a reactant permeable, liquidcrystalline state, said diffusion layer effecting the transition between said impermeable and permeable states at a clearly defined transition temperature; and container means for enclosing said time-temperature sensitive component, said container means including a transparent face for viewing said time-temperature component.
Claim 12
Dependent Claim
99 words
A time-temperature indicating device for indicating deterioration of perishable goods and the like, said device comprising: a time-temperature sensitive component including a reactant material and an indicator responsive to contact by said reactant to produce a visible reaction, said reactant and indicator being normally separated by a diffusion layer having an impermeable, pseudo-crystalline state and a reactant permeable, liquidcrystalline state, said diffusion layer effecting the transition between said impermeable and permeable states at a clearly defined transition temperature; and container means for enclosing said time-temperature sensitive component, said container means including a transparent face for viewing said time-temperature component.
Claim 13
Dependent Claim
33 words
The device of claim 10 wherein said container means comprises an upper and a lower sheet of a hydrophilic substantially liquid impermeable material, said sheets being bonded together at the peripheral portions thereof.
Claim 14
Dependent Claim
28 words
The device of claim 11 further including a liquid permeable membrane disposed on each side of said diffusion layer, between said layer and said reactant and indicator, respectively.
Claim 15
Dependent Claim
54 words
The device of claim 10 wherein said diffusion layer comprises a film of a surface-active material having oriented molecular structure, said surface-active material selected from the group consisting of dioleoyl lecithin, egg yolk lecithin, 1 stearoyl2 oleoyl lecithin, soya lecithin, dimyristoyl lecithin, dipalmitoyl lecithin, phosphatidyl choline, phosphatidyl serine, decanol/sodium caprylate and hexanol/cetylmethyl ammonium bromide.
Claim 16
Dependent Claim
22 words
The device of claim 10 wherein said diffusion layer has a transition temperature of between about -22° C and about 60° C.
Claim 17
Dependent Claim
30 words
The device of claim 10 wherein reactant material is selected from the group consisting of lauryldiethylamine, decanoic acid, aniline, m-chloroaniline, guanidine, beta-napthol, pyridine, dodecanoic acid, propanoic acid, and oleic acid.
Claim 18
Dependent Claim
27 words
The device of claim 10 wherein the time required for diffusion of said reactant through said diffusion layer is between about 3 hours to about 7 days.
Claim 19
Dependent Claim
21 words
The device of claim 10 wherein said reactant material is disposed as a layer on one side of said diffusion layer.
Claim 20
Dependent Claim
22 words
The device of claim 11 wherein said indicator is bonded to the inner surface of one of said upper and lower sheets.
Claim 21
Dependent Claim
48 words
The device of claim 10 wherein said time-temperature component comprising a diffusion layer of dimyristoyl lecithin having a transition temperature of about 24° C, lauryldiethylamine as said reactant having a diffusion time through said diffusion layer of about 24 hours, and alizarin as an indicator of said reactant.
Claim 22
Dependent Claim
25 words
The device of claim 10 wherein said diffusion layer is dimyristoyl lecithin having about 1% by weight thereof of lauryldiethylamine dispersed in said diffusion layer.
Claim 23
Dependent Claim
106 words
A time-temperature indicating device for indicating deterioration of perishable goods and the like, said device comprising: a time-temperature sensitive component including a reactant material and an indicator responsive to contact by said reactant material to produce a visible reaction, said reactant material being dispersed in a diffusion layer disposed adjacent said indicator, and said diffusion layer having an impermeable, pseudo-crystalline state and a reactant-permeable, liquid-crystalline state, wherein said diffusion layer effects a transition between said impermeable and permeable states at a clearly defined transition temperature; and container means for enclosing said time-temperature sensitive component, said container means including a transparent face for viewing said time-temperature component.
Claim 24
Dependent Claim
106 words
A time-temperature indicating device for indicating deterioration of perishable goods and the like, said device comprising: a time-temperature sensitive component including a reactant material and an indicator responsive to contact by said reactant material to produce a visible reaction, said reactant material being dispersed in a diffusion layer disposed adjacent said indicator, and said diffusion layer having an impermeable, pseudo-crystalline state and a reactant-permeable, liquid-crystalline state, wherein said diffusion layer effects a transition between said impermeable and permeable states at a clearly defined transition temperature; and container means for enclosing said time-temperature sensitive component, said container means including a transparent face for viewing said time-temperature component.
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) | 1980-11-07 | 1981-05-09 | 1981-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-07 | 1985-05-09 | 1985-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-07 | 1989-05-09 | 1989-11-08 | $7700.00 | Window Closed / Lapsed |