US3748218A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rigid multilayer formed sheet structures
Assignee: Dow Chemical Co
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Filing: 1971-10-04
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Granted: 1973-07-24
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Expires: 1991-10-04
Abstract
Abstract THIS INVENTION PROVIDES ECONOMICAL MULTILAYER SHEETS THAT COMBINE HIGH BARRIER LAYERS WITH LAYERS OF RIGID POLYVINYL CHLORIDE OR IMPACT POLYSTYRENE.
Inventors
- 👤 R Newman
- 👤 W Schrenk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:07
CPC Classifications
B; B32; B32B; B32B27/00; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31924; Y10T428/31928; Y10T428/31931; Y10T428/31935
Claims Analysis
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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) | 1976-07-23 | 1977-01-22 | 1977-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-23 | 1981-01-22 | 1981-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-23 | 1985-01-22 | 1985-07-24 | $7700.00 | Window Closed / Lapsed |