US4182850A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Non-solvent precipitation of polymer composition
Assignee: Dow Chemical Co
•
Filing: 1977-12-19
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Granted: 1980-01-08
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Expires: 1997-12-19
Abstract
Abstract Production of polycarbonate or phenolphthalein polycarbonate copolymers and method for recovery of solid copolymer from solution.
Inventors
- 👤 Cary S. Marshall
- 👤 Robert S. Steffanson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:57
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; C08J3/14; C08G; C08G64/00; C08G64/40; C08G64/403; C08J2369/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
78 words
A method for recovering solid polycarbonate polymer from a polycarbonate-solvent solution which comprises introducing concurrently into a high speed shearing chamber a stream of said solution and a turbulent stream of a non-solvent for said polycarbonate polymer, said non-solvent being maintained at a temperature which is maintained below the boiling point of the polycarbonate solvent, to form a mixture comprising solid polycarbonate polymer particles, solvent and non-solvent and thereafter separating said solid particles from said solvent and non-solvent.
Claim 2
Independent Claim
78 words
A method for recovering solid polycarbonate polymer from a polycarbonate-solvent solution which comprises introducing concurrently into a high speed shearing chamber a stream of said solution and a turbulent stream of a non-solvent for said polycarbonate polymer, said non-solvent being maintained at a temperature which is maintained below the boiling point of the polycarbonate solvent, to form a mixture comprising solid polycarbonate polymer particles, solvent and non-solvent and thereafter separating said solid particles from said solvent and non-solvent.
Claim 3
Dependent Claim
16 words
The method of claim 1 wherein the polycarbonate solution is prepared by the phosgenation of bisphenol-A.
Claim 4
Dependent Claim
25 words
The method of claim 1 wherein the polycarbonate solution comprises from about 1 to about 40% by weight phenolphthalein polycarbonate polymer and the remainder solvent.
Claim 5
Dependent Claim
11 words
The method of claim 2 wherein the solvent is methylene chloride.
Claim 6
Dependent Claim
11 words
The method of claim 3 wherein the solvent is methylene chloride.
Claim 7
Dependent Claim
20 words
The method of claim 1 wherein said streams are contacted and sheared in the discharge chamber of a centrifugal pump.
Claim 8
Dependent Claim
20 words
The method of claim 4 wherein said streams are contacted and sheated in the discharge chamber of a centrifugal pump.
Claim 9
Dependent Claim
20 words
The method of claim 5 wherein said streams are contacted and sheared in the discharge chamber of a centrifugal pump.
References Cited (Backward Citations)
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Cited
US3036036A
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US3214407A
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US3267074A
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Cited
US3264262A
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US3264263A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-01-07 | 1983-07-09 | 1984-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-01-07 | 1987-07-09 | 1988-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-01-07 | 1991-07-09 | 1992-01-08 | $7700.00 | Window Closed / Lapsed |