US3214407A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making powdered polycarbonate
Assignee: Armstrong World Industries Inc
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Filing: 1962-03-19
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Granted: 1965-10-26
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Expires: 1982-03-19
Abstract
No abstract record available.
Inventors
- 👤 Butterworth Richard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:57
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; C08J3/14; C08J2369/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
90 words
A METHOD OF MAKING POWDERED RESINOUS POLY(2,2PROPANE BIS(4-PHENYL CARBONATE)) WHICH COMPRISES DISSOLVING SAID POLYCARBONATE IN A SOLVENT THEREFOR TO FORM A SOLUTION CONTAINING 0.5-50% BY WEIGHT OF SAID POLYCARBONATE, SAID SOLVENT CONSISTING ESSENTIALLY OF A LIQUID CHLORINATED METHANE CONTAINING AT LEAST ONE HYDROGEN ATOM, PRECIPITATING THE POLYCARBONATE BY ADDING TO SAID SOLUTION AN ADDITIVE CONSISTING ESSENTIALLY OF AN ALIPHATIC KETONE CONTAINING 4-7 CARBON ATOMS IN AN AMOUNT OF FROM 15-500% BY VOLUME BASED ON THE VOLUME OF SAID SOLUTION AND THEREAFTER RECOVERING THE PRECIPITATED POWDERED POLYCARBONATE FROM THE LIQUID MEDIUM.
Claim 2
Independent Claim
90 words
A METHOD OF MAKING POWDERED RESINOUS POLY(2,2PROPANE BIS(4-PHENYL CARBONATE)) WHICH COMPRISES DISSOLVING SAID POLYCARBONATE IN A SOLVENT THEREFOR TO FORM A SOLUTION CONTAINING 0.5-50% BY WEIGHT OF SAID POLYCARBONATE, SAID SOLVENT CONSISTING ESSENTIALLY OF A LIQUID CHLORINATED METHANE CONTAINING AT LEAST ONE HYDROGEN ATOM, PRECIPITATING THE POLYCARBONATE BY ADDING TO SAID SOLUTION AN ADDITIVE CONSISTING ESSENTIALLY OF AN ALIPHATIC KETONE CONTAINING 4-7 CARBON ATOMS IN AN AMOUNT OF FROM 15-500% BY VOLUME BASED ON THE VOLUME OF SAID SOLUTION AND THEREAFTER RECOVERING THE PRECIPITATED POWDERED POLYCARBONATE FROM THE LIQUID MEDIUM.
References Cited (Backward Citations)
US3112292A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-10-25 | 1969-04-26 | 1969-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-10-25 | 1973-04-26 | 1973-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-10-25 | 1977-04-26 | 1977-10-26 | $7700.00 | Window Closed / Lapsed |