US4115526A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of reactive tungsten and derivatives thereof
Assignee: Osram Sylvania Inc
•
Filing: 1977-06-17
•
Granted: 1978-09-19
•
Expires: 1997-06-17
Abstract
Abstract Process for the preparation of reactive tungsten comprising reducing a tungsten compound in a reducing atmosphere at temperatures ranging from about 450° C to 700° C. The reactive tungsten can be readily converted to WC, W 2 C or WN.
Inventors
- 👤 James J. Auborn
- 👤 Elizabeth A. Trickett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:19
CPC Classifications
C; C22; C22B; C22B34/00; C22B34/30; C22B34/36; C01; C01B; C01B21/00; C01B21/06; C01B21/0615; C01B21/062; C01B32/00; C01B32/90; C01B32/914; C01B32/949
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
72 words
A continuous process of preparing binary compounds of tungsten and carbon comprising the steps of reducing an oxygen-containing tungsten compound by heating said compound in a hydrogen-containing atmosphere at temperatures ranging from about 485° C. to about 585° C., and carburizing the resultant material in a methane-containing atmosphere at temperatures in the range from about 485° C. to about 600° C. whereby there is produced finely divided ditungsten carbide (W 2 C).
Claim 2
Dependent Claim
72 words
A continuous process of preparing binary compounds of tungsten and carbon comprising the steps of reducing an oxygen-containing tungsten compound by heating said compound in a hydrogen-containing atmosphere at temperatures ranging from about 485° C. to about 585° C., and carburizing the resultant material in a methane-containing atmosphere at temperatures in the range from about 485° C. to about 600° C. whereby there is produced finely divided ditungsten carbide (W 2 C).
References Cited (Backward Citations)
US985386A
Cited
US1175693A
Cited
US1278580A
Cited
US3077385A
Cited
GB1011166A
Cited
US3850614A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-09-18 | 1982-03-20 | 1982-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-09-18 | 1986-03-20 | 1986-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-09-18 | 1990-03-20 | 1990-09-19 | $7700.00 | Window Closed / Lapsed |