Patent US3753952A successfully refreshed from Google Patents.
US3753952A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photodegradable composition
Assignee: University of Toronto
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Filing: 1971-04-19
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Granted: 1973-08-21
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Expires: 1991-04-19
Abstract
Abstract PLASTICS MATERIALS SUITABLE FOR USE IN PACKAGING ARE PROVIDED, WHICH PHOTODEGRADE UPON EXPOSURE TO DIRECT SUNLIGHT, BUTT WHICH HAVE INDEFINITE STORAGE LIFE OTHERWISE. THE MATERIALS ARE POLYMERS OF COMMON VINYLIDENE MONOMERS SUCH AS ETHYLENE, STYRENE AND METHYL METHACRYLATE, CONTAINING 0.1-5 MOLE PERCENT OF KETO CARBONYL GROUPS LOCATED IN SIDE CHAINS BUT ADJACENT THE MAIN CHAIN OF THE POLYMER. THESE KETO GROUPS ABSORB U.V. RADIATION AND CAUSE PHOTODEGRADATION OF THE POLYMER.
Inventors
- 👤 J Guillet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:53
CPC Classifications
C; C08; C08F; C08F220/00; C08F220/02; C08F220/10; C08F220/12; C08F220/14; Y; Y10; Y10S; Y10S220/00; Y10S220/30
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-20 | 1977-02-19 | 1977-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-20 | 1981-02-19 | 1981-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-20 | 1985-02-19 | 1985-08-21 | $7700.00 | Window Closed / Lapsed |