Patent US3935960A successfully refreshed from Google Patents.
US3935960A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tamper indicator tape
Assignee: 3M Co
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Filing: 1975-01-30
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Granted: 1976-02-03
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Expires: 1995-01-30
Abstract
Abstract An easy opening, hermetically sealed container with a preformed aperture is covered by a tape closure having on its outer surface an indicator layer which changes color when flexed, thereby indicating whether the closure has been handled or tampered with.
Inventors
- 👤 Lew W. Cornell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:07
CPC Classifications
B; B65; B65D; B65D55/00; B65D55/02; B65D55/026; B65D17/00; B65D17/50; B65D17/501; B65D17/502; G; G09; G09F; G09F3/00; G09F3/02; G09F3/0291; G09F3/0292; B65D2401/00; B65D2401/55; B65D2517/00; B65D2517/0001; B65D2517/001; B65D2517/0013; B65D2517/0058; B65D2517/0059; B65D2517/0061; B65D2517/50; B65D2517/5002; B65D2517/5024; B65D2517/5032; B65D2517/5035; B65D2517/5072; B65D2517/5083; Y; Y10; Y10S; Y10S206/00; Y10S206/807
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
94 words
An adhesive tape having particular utility in preparing a sealed container comprising in combination a sheet backing material to one face of which is firmly adherently bonded a smooth, uniform coating of normally tacky and pressure-sensitive adhesive and to the other face of which is firmly adhesively bonded an indicator layer comprising a strong flexible binder matrix having a Young's modulus at 2% elongation of at least about 125,000 pounds per square inch, said binder containing dispersed throughout, a solid, color-forming substance and capsules containing a liquid dye precursor reactable with said color-forming substance.
Claim 2
Dependent Claim
94 words
An adhesive tape having particular utility in preparing a sealed container comprising in combination a sheet backing material to one face of which is firmly adherently bonded a smooth, uniform coating of normally tacky and pressure-sensitive adhesive and to the other face of which is firmly adhesively bonded an indicator layer comprising a strong flexible binder matrix having a Young's modulus at 2% elongation of at least about 125,000 pounds per square inch, said binder containing dispersed throughout, a solid, color-forming substance and capsules containing a liquid dye precursor reactable with said color-forming substance.
Claim 3
Dependent Claim
22 words
The tape of claim 1 where said color-forming solid reactant is nickel rosinate and said liquid color former is a dithiooxamide derivative.
Claim 4
Dependent Claim
16 words
The tape of claim 1, where said binder contains titanium dioxide dispersed in the indicator layer.
References Cited (Backward Citations)
US3516852A
Cited
US3292828A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-02-02 | 1979-08-04 | 1980-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-02-02 | 1983-08-04 | 1984-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-02-02 | 1987-08-04 | 1988-02-03 | $7700.00 | Window Closed / Lapsed |