US3705872A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of bonded particles as a material of construction
Assignee: Shell USA Inc
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Filing: 1971-04-05
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Granted: 1972-12-12
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Expires: 1991-04-05
Abstract
Abstract FOUNDRY CORES ARE PREPARED BY (1) MIXING FROM ABOUT 90 TO 99 PARTS BY WEIGHT OF FOUNDRY SAND WITH FROM 1 TO 10 PARTS BY WEIGHT OF A POLYEPOXIDE BINDER, (2) MIXING SAID BLEND WITH A CURING AMOUNT OF A BORON TRIBALIDE COMPLEX, ESPECIALLY BORON TRIFLUORIDE DIHYDRATE, IN AN OXYGENATED HYDROCARBON, (3) PACKING THE BLEND INTO SUITABLE FORMS AND (4) ALLOWING THE POLYEPOXIDE TO CURE WITH OR WITHOUT HEATING.
Inventors
- 👤 Clifford V Wittenwyler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 03:51
CPC Classifications
C; C08; C08G; C08G59/00; C08G59/18; C08G59/68; C08G59/72; B; B22; B22C; B22C1/00; B22C1/16; B22C1/20; B22C1/22; B22C1/2233; B22C1/226; Y; Y10; Y10S; Y10S521/00; Y10S521/919
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-12-12 | 1976-06-12 | 1976-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-12 | 1980-06-12 | 1980-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-12 | 1984-06-12 | 1984-12-12 | $7700.00 | Window Closed / Lapsed |