Patent US2758987A successfully refreshed from Google Patents.
US2758987A
Expired / Lapsed
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Optically active homopolymers containing but one antipodal species of an alpha-monohydroxy monocarboxylic acid
Assignee: EIDP Inc
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Filing: 1952-06-05
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Granted: 1956-08-14
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Expires: 1972-06-05
Abstract
No abstract record available.
Inventors
- 👤 Paul L Salzberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:22
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/78; C08G63/82; C08G63/823
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
35 words
AN OPTICALLY ACTIVE POLYMER, COLD-DRAWABLE TO THE EXTENT OF AT LEAST 200%, OF INHERENT VISCOSITY AT 25* C. IN BENZENE OF AT LEAST 0.4, WHOSE REPEATING UNITS CONSIST OF ONE ANTIPODAL SPECIES OF ALPHA-HYDROXYPROPIONIC ACID.
References Cited (Backward Citations)
US1095205A
Cited
US1995970A
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US2144352A
Cited
GB550837A
Cited
US2471023A
Cited
US2585427A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-08-14 | 1960-02-13 | 1960-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-08-14 | 1964-02-13 | 1964-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-08-14 | 1968-02-13 | 1968-08-14 | $7700.00 | Window Closed / Lapsed |