US2921923A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of producing improved epoxy resin compositions
Assignee: Shell Development Co
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Filing: 1955-12-01
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Granted: 1960-01-19
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Expires: 1975-12-01
Abstract
No abstract record available.
Inventors
- 👤 Bruin Pieter
- 👤 Oosterhof Hendricus Anthonius
- 👤 Selman Jan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:53
CPC Classifications
C; C08; C08G; C08G59/00; C08G59/18; C08G59/40; C08G59/42
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
176 words
A PROCESS FOR PRODUCING AN EPOXY RESIN COMPOSITION CONTAINING A POLYCARBOXYLIC ACID ANHYDRIDE HAVING IMPROVED WORKING TIME WHICH COMPRISES MIXING THE ANHYDRIDE WITH AN EPOXY RESIN WHICH IS A GLYCIDYL POLYETHER OF A POLYHYDRIC PHENOL AND HAS AN AVERAGE OF MORE THAN 1 EPOXY GROUP PER MOLECULE IN AN AMOUNT SO AS TO PROYIDE ABOUT 0.75 TO 1.25 ANHYDRIDE GROUPS PER EPOXIDE GROUP, WHICH EPOXY RESIN HAD BEEN PREPARED BY CONDENSING A POLYHYDRIC PHENOL WITH EPICHLOROHYDRIN IN THE PRESENCE OF AN ALKALI METAL HYDROXIDE WHEREIN THE ALKALI METAL HYDROXIDE IS ADDED TO THE REACTION MIXTURE IN SMALL INCREMENTS AND HAS BEEN WASHED WITH WATER ACIDIFIED SUFFICIENTLY THAT THE PH OF THE OBTAINED WASH WATER IS NOT HIGHER THAN 5.5 FOR ABOUT 15 TO 120 MINUTES, AFTER WHICH THE EXCESS ACID IS REMOVED FROM THE TREATED RESIN BY REPEATED WASHING WITH WATER, SAID COMPOSITION RETAIN ING MOBILE FLUIDITY WHEN MOLTEN FOR A SUBSTANTIALLY LONGER TIME THAN IS THE CASE WITH A CORRESPONDING COMPOSITION CONTAINING EPOXY RESIN WHICH HAD NOT BEEN SUBJECTED TO SAID TREATMENT WITH ACIDIFIED WATER.
Claim 2
Dependent Claim
176 words
A PROCESS FOR PRODUCING AN EPOXY RESIN COMPOSITION CONTAINING A POLYCARBOXYLIC ACID ANHYDRIDE HAVING IMPROVED WORKING TIME WHICH COMPRISES MIXING THE ANHYDRIDE WITH AN EPOXY RESIN WHICH IS A GLYCIDYL POLYETHER OF A POLYHYDRIC PHENOL AND HAS AN AVERAGE OF MORE THAN 1 EPOXY GROUP PER MOLECULE IN AN AMOUNT SO AS TO PROYIDE ABOUT 0.75 TO 1.25 ANHYDRIDE GROUPS PER EPOXIDE GROUP, WHICH EPOXY RESIN HAD BEEN PREPARED BY CONDENSING A POLYHYDRIC PHENOL WITH EPICHLOROHYDRIN IN THE PRESENCE OF AN ALKALI METAL HYDROXIDE WHEREIN THE ALKALI METAL HYDROXIDE IS ADDED TO THE REACTION MIXTURE IN SMALL INCREMENTS AND HAS BEEN WASHED WITH WATER ACIDIFIED SUFFICIENTLY THAT THE PH OF THE OBTAINED WASH WATER IS NOT HIGHER THAN 5.5 FOR ABOUT 15 TO 120 MINUTES, AFTER WHICH THE EXCESS ACID IS REMOVED FROM THE TREATED RESIN BY REPEATED WASHING WITH WATER, SAID COMPOSITION RETAIN ING MOBILE FLUIDITY WHEN MOLTEN FOR A SUBSTANTIALLY LONGER TIME THAN IS THE CASE WITH A CORRESPONDING COMPOSITION CONTAINING EPOXY RESIN WHICH HAD NOT BEEN SUBJECTED TO SAID TREATMENT WITH ACIDIFIED WATER.
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) | 1963-01-18 | 1963-07-20 | 1964-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-01-18 | 1967-07-20 | 1968-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-01-18 | 1971-07-20 | 1972-01-19 | $7700.00 | Window Closed / Lapsed |