US3837997A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Boron nitride products
Assignee: Unifrax I LLC
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Filing: 1971-03-16
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Granted: 1974-09-24
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Expires: 1991-03-16
Abstract
Abstract A LOW-DENSITY PRODUCT COMPRISING BORON NITRIDE FIBERS BONDED BY BORON NITRIDE FORMED IN SITU IS PRODUCED BY HEATING A FORMED MASS OR BORON NITRIDE FIBERS THAT HAS BEEN IMPREGNATED WITH BORIC ACID SOLUTION TO AN ELEVATED TEMPERATURE IN AMMONIA. THE FIBROUS MASS MAY BE SHAPED BEFORE OR AFTER IMPREGNATION WITH THE SOLUTION. INCORPORATION OF A NITROGENOUS MATERIAL IN THE SOLUTION GIVES IMPROVED RESULTS AND THE DENSITY MAY BE INCREASED, IF DESIRED, BY THE ADDITION OF FILLERS. PURITY OF THE PRODUCT IS AFFECTED BY THE NITRIDING TEMPERATURE EMPLOYED.
Inventors
- 👤 J Economy
- 👤 R Highsmith
- 👤 J Mason
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:01
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/583; B; B29; B29C; B29C70/00; B29C70/04; B29C70/06; B29C70/10; B29C70/12; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2916
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) | 1977-09-23 | 1978-03-25 | 1978-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-23 | 1982-03-25 | 1982-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-23 | 1986-03-25 | 1986-09-24 | $7700.00 | Window Closed / Lapsed |