Patent US3054772A successfully refreshed from Google Patents.
US3054772A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of polycarbonates
Assignee: Onderzoekings Instituut Research
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Filing: 1958-05-14
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Granted: 1962-09-18
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Expires: 1978-05-14
Abstract
No abstract record available.
Inventors
- 👤 Jibben Bart Paul
- 👤 Overmars Henricus Gerar Joseph
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:45
CPC Classifications
C; C08; C08G; C08G64/00; C08G64/20; C08G64/26; C08G64/28; C08G64/22; C08G64/24
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
59 words
A PROCESS FOR THE PREPARATION OF MACROMOLECULAR POLYCARBONATES COMPRISING REACTING AN ORGANIC DIMONOHYDROXY ARYL ALKANE WITH A COMPOUND SELECTED FROM THE GROUP CONSISTING OF PHOSGENE AND A CHLOROCARBONIC ACID ESTER OF AN ORGANIC DIMONOHYDROXY ARLY ALKANE TO FORM SAID POLYCARBONATE IN THE PRESENCE OF CATALYTIC AMOUNTS OF FORMALDEHYDE AS THE PROMOTER OF THE POLYESTERIFICATION REACTION AND AN ACID-BINDING SUBSTANCE.
Claim 2
Dependent Claim
59 words
A PROCESS FOR THE PREPARATION OF MACROMOLECULAR POLYCARBONATES COMPRISING REACTING AN ORGANIC DIMONOHYDROXY ARYL ALKANE WITH A COMPOUND SELECTED FROM THE GROUP CONSISTING OF PHOSGENE AND A CHLOROCARBONIC ACID ESTER OF AN ORGANIC DIMONOHYDROXY ARLY ALKANE TO FORM SAID POLYCARBONATE IN THE PRESENCE OF CATALYTIC AMOUNTS OF FORMALDEHYDE AS THE PROMOTER OF THE POLYESTERIFICATION REACTION AND AN ACID-BINDING SUBSTANCE.
References Cited (Backward Citations)
US1697713A
Cited
US1933124A
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US2027337A
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US2493075A
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BE546375A
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US2874046A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1965-09-17 | 1966-03-19 | 1966-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-09-17 | 1970-03-19 | 1970-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-09-17 | 1974-03-19 | 1974-09-18 | $7700.00 | Window Closed / Lapsed |