US4499192A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silicon nitride sintered products having high corrosion resistance and process for production thereof
Assignee: Niterra Co Ltd
•
Filing: 1982-11-24
•
Granted: 1985-02-12
•
Expires: 2002-11-24
Abstract
Abstract A silicon nitride sintered product and processes for the production thereof are described, wherein the product comprises from 75 to 97.9% by weight of silicon nitride, from 2 to 20% by weight of yttrium oxide and cerium oxide in a molar ratio of cerium oxide to yttrium oxide of 0.4/1 to 4/1, and from 0.1 to 8% by weight of aluminum oxide.
Inventors
- 👤 Toru Shimamori
- 👤 Yoshinori Hattori
- 👤 Yasushi Matsuo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:35
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/593
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
58 words
A silicon nitride sintered product having high corrosion resistance consisting essentially of from 75 to 97.9% by weight of silicon nitride, from 2 to 20% by weight of yttrium oxide and cerium oxide in a molar ratio of cerium oxide to yttrium oxide of from 0.4/1 to 4/1, and from 0.1 to 8% by weight of aluminum oxide.
Claim 2
Dependent Claim
58 words
A silicon nitride sintered product having high corrosion resistance consisting essentially of from 75 to 97.9% by weight of silicon nitride, from 2 to 20% by weight of yttrium oxide and cerium oxide in a molar ratio of cerium oxide to yttrium oxide of from 0.4/1 to 4/1, and from 0.1 to 8% by weight of aluminum oxide.
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) | 1988-02-12 | 1988-08-13 | 1989-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-12 | 1992-08-13 | 1993-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-12 | 1996-08-13 | 1997-02-12 | $7700.00 | Window Closed / Lapsed |