US3714320A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cold extrusion process
Assignee: Shell USA Inc
•
Filing: 1968-09-30
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Granted: 1973-01-30
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Expires: 1988-09-30
Abstract
Abstract Polypropylene articles of high impact resistance at low temperatures and of improved tensile properties which permit their use at substantially higher tensile loads than conventionally produced articles of polypropylene, are produced by deforming the polypropylene in the solid state under compressive stress. A form of polypropylene is disclosed which is characterized by absence of inhomogeneous deformation under tension, absence of whitening under tension until strained beyond 150 percent deformation, ductility at temperatures of 0*C and below, and an apparent glass transition temperature, determined by torsional damping at 1 cycle per second, of about 15*C.
Inventors
- 👤 R Shaw
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:42
CPC Classifications
B; B29; B29C; B29C67/00; B29C67/0029; B29C48/00; B29C55/00; B29C55/30; B29C48/03; B29C48/05; B29C48/07; B29C48/08; B29K; B29K2023/00; B29K2023/10; B29K2023/12
Claims Analysis
Total Claims: 0
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |