US3207818A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Methods of forming spherical particles of crystallizable thermoplastic polymers
Assignee: AT&T Inc
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Filing: 1963-12-27
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Granted: 1965-09-21
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Expires: 1983-12-27
Abstract
No abstract record available.
Inventors
- 👤 Donald I Marshall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:15
CPC Classifications
B; B29; B29B; B29B9/00; B29B9/02; B29B9/06; B29B9/065
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
69 words
THE METHOD OF FORMING MINUTE, GENERALLY SPHERICAL PARTICLES OF ISOTACTIC POLYPROPYLENE, WHICH COMPRISES: PREPARING A SOLUTION OF ABOUT 10% TO 70% BY WEIGHT OF ISOTACTIC POLYPROPYLENE IN A SOLVENT; FORMING THE SOLUTION INTO INDIVIDUAL DROPLETS; COOLING THE INDIVIDUAL DROPLETS OF THE SOLUTION IN AN IMMISCIBLE COOLING MEDIUM TO A TEMPERATURE AND FOR A TIME SUFFICIENT TO PRECIPITATE THE POLYPROPYLENE WITHIN EACH DROPLET IN THE FORM OF A CLUSTER OF
Claim 2
Independent Claim
69 words
THE METHOD OF FORMING MINUTE, GENERALLY SPHERICAL PARTICLES OF ISOTACTIC POLYPROPYLENE, WHICH COMPRISES: PREPARING A SOLUTION OF ABOUT 10% TO 70% BY WEIGHT OF ISOTACTIC POLYPROPYLENE IN A SOLVENT; FORMING THE SOLUTION INTO INDIVIDUAL DROPLETS; COOLING THE INDIVIDUAL DROPLETS OF THE SOLUTION IN AN IMMISCIBLE COOLING MEDIUM TO A TEMPERATURE AND FOR A TIME SUFFICIENT TO PRECIPITATE THE POLYPROPYLENE WITHIN EACH DROPLET IN THE FORM OF A CLUSTER OF
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-09-20 | 1969-03-22 | 1969-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-09-20 | 1973-03-22 | 1973-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-09-20 | 1977-03-22 | 1977-09-21 | $7700.00 | Window Closed / Lapsed |