US3438909A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing flexible epoxy resins
Assignee: Siemens AG
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Filing: 1963-06-24
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Granted: 1969-04-15
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Expires: 1983-06-24
Abstract
No abstract record available.
Inventors
- 👤 Wolfgang Kleeberg
- 👤 Hans Denk
- 👤 Klaus-Robert Hauschildt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:25
CPC Classifications
H; H01; H01B; H01B3/00; H01B3/18; H01B3/30; H01B3/42; C; C08; C08L; C08L63/00; H01B3/40
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
110 words
A METHOD FOR THE MANUFACTURE OF A FLEXIBLE EPOXY RESIN WHICH COMPRISES EFFECTING A REACTION OF A MIXTURE OF (A) A COMPONENT FORMED BY AT LEAST 50% ESTERIFYING A MIXTURE OF CASTOR OIL WITH A DICARBOXYLIC ANHYDRIDE IN A PROPORTION SUCH THAT THE RATIO OF CARBOXYLIC EQUIVALENT TO HYDROXYL EQUIVALENT IS GREATER THAN TWO TO FORM AN ESTERIFICATION PRODUCT CONTAINING AT LEAST ONE ALIPHATIC CHAIN OF AT LEAST FOUR CARBON ATOMS AS AN ESSENTIAL MOLECULAR ELEMENT, AND (B) AT LEAST ONE EPOXY COMPOUND CONTAINING TWO EPOXY GROUPS IN THE MOLECULE, THE RATIO OF THE TOTAL CARBOXYLIC EQUIVALENTS TO THE EPOXY, GROUPS BEING AT LEAST 1.5 AND NOT GREATER THAN 2.
Claim 2
Independent Claim
110 words
A METHOD FOR THE MANUFACTURE OF A FLEXIBLE EPOXY RESIN WHICH COMPRISES EFFECTING A REACTION OF A MIXTURE OF (A) A COMPONENT FORMED BY AT LEAST 50% ESTERIFYING A MIXTURE OF CASTOR OIL WITH A DICARBOXYLIC ANHYDRIDE IN A PROPORTION SUCH THAT THE RATIO OF CARBOXYLIC EQUIVALENT TO HYDROXYL EQUIVALENT IS GREATER THAN TWO TO FORM AN ESTERIFICATION PRODUCT CONTAINING AT LEAST ONE ALIPHATIC CHAIN OF AT LEAST FOUR CARBON ATOMS AS AN ESSENTIAL MOLECULAR ELEMENT, AND (B) AT LEAST ONE EPOXY COMPOUND CONTAINING TWO EPOXY GROUPS IN THE MOLECULE, THE RATIO OF THE TOTAL CARBOXYLIC EQUIVALENTS TO THE EPOXY, GROUPS BEING AT LEAST 1.5 AND NOT GREATER THAN 2.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-04-14 | 1972-10-14 | 1973-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-04-14 | 1976-10-14 | 1977-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-04-14 | 1980-10-14 | 1981-04-15 | $7700.00 | Window Closed / Lapsed |