US3642970A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making porous bodies
Assignee: Daicel Corp
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Filing: 1969-07-09
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Granted: 1972-02-15
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Expires: 1989-07-09
Abstract
Abstract POROUS THERMOPLASTIC BODIES HAVING A RELATIVELY HICH MECHANICAL STRENGTH AND A HICH AND UNIFORM POROSITY IN THE RANGE OF ABOUT 27% TO 45% ARE MADE BY FILLING A MOLD WITH SPEREICAL PARTICLES OF A THERMOPLASTIC POLYMER CONTAINING FROM 0.3 TO 5% OF UNREACTED MONOMER AND THEN HEATING THE SPERICAL PARTICLES TO A TEMPERATURE ABOVE THE SOFTENING POINT, BUT BELOW THE MELTIG POINT, OF THE POLYMER IN THE ABSENCE OF EXTERNALLY APPLIED PRESSURE.
Inventors
- 👤 Akira Hagitani
- 👤 Yoshishige Morita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:22
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/24
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) | 1975-02-14 | 1975-08-16 | 1976-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-14 | 1979-08-16 | 1980-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-14 | 1983-08-16 | 1984-02-15 | $7700.00 | Window Closed / Lapsed |