Patent US3046255A successfully refreshed from Google Patents.
US3046255A
Expired / Lapsed
US
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Process for preparing polycarbonates
Assignee: PPG Industries Inc
•
Filing: 1957-06-20
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Granted: 1962-07-24
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Expires: 1977-06-20
Abstract
No abstract record available.
Inventors
- 👤 Strain Franklin
- 👤 Henry C Stevens
- 👤 George E Foltz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:09
CPC Classifications
C; C08; C08G; C08G64/00; C08G64/20; C08G64/26
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
55 words
A METHOD OF PRODUCING A HIGH MOLECULAR WEIGHT POLYCARBONATE WHICH COMPRISES REACTING AN ACYCLIC, SATURATED DIOL AND A DIHALOFORMATE OF A DIOL IN A HETEROGENEOUS MEDIUM CONTAINING AN AQUEOUS ALKALINE PHASE AND AN ESSENTIALLY WATER INSOLUBLE, INERT ORGANIC SOLVENT FOR THE POLYCARBONATE SELECTED FROM THE GROUP CONSISTING NITROALKANES, DIALKYL ETHERS AND PARTIALLY CHLORIDE ALIPHATIC HYDROCARBONS.
Claim 2
Independent Claim
55 words
A METHOD OF PRODUCING A HIGH MOLECULAR WEIGHT POLYCARBONATE WHICH COMPRISES REACTING AN ACYCLIC, SATURATED DIOL AND A DIHALOFORMATE OF A DIOL IN A HETEROGENEOUS MEDIUM CONTAINING AN AQUEOUS ALKALINE PHASE AND AN ESSENTIALLY WATER INSOLUBLE, INERT ORGANIC SOLVENT FOR THE POLYCARBONATE SELECTED FROM THE GROUP CONSISTING NITROALKANES, DIALKYL ETHERS AND PARTIALLY CHLORIDE ALIPHATIC HYDROCARBONS.
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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) | 1965-07-23 | 1966-01-22 | 1966-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-07-23 | 1970-01-22 | 1970-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-07-23 | 1974-01-22 | 1974-07-24 | $7700.00 | Window Closed / Lapsed |