US4207306A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing polycrystalline ceramic oxides
Assignee: Sanofi SA
•
Filing: 1977-12-21
•
Granted: 1980-06-10
•
Expires: 1997-12-21
Abstract
Abstract A novel ceramic form of hydroxylapatite and a novel ceramic product comprising a mixture of the latter and whitlockite, the preparation of these ceramics and dental restorative compositions and dental and surgical prosthetic materials containing the same are disclosed. Also described is a novel and improved process for producing polycrystalline ceramic oxides.
Inventors
- 👤 Michael Jarcho
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:33
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/447; A; A61; A61K; A61K6/00; A61K6/80; A61K6/802; A61K6/804; A61K6/807; A61K6/813; A61K6/816; A61K6/831; A61K6/838; A61L; A61L27/00; A61L27/02; A61L27/10; A61L27/12; C01; C01B; C01B25/00; C01B25/16; C01B25/26; C01B25/32; C01B25/325; A61F; A61F2310/00; A61F2310/00005; A61F2310/00179; A61F2310/00185; A61F2310/00203; A61F2310/00293
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
87 words
A process for producing a dense polycrystalline ceramic ferric oxide which comprises reacting ferric ion with hydroxide ion in aqueous medium to produce a gelatinous precipitate of the corresponding hydrous oxide; separating the gelatinous precipitate from solution; heating the gelatinous precipitate up to a temperature of at least 1000° C. but below that at which decomposition occurs and at a rate effective to produce a substantially fracture-free ceramic; and maintaining said temperature for sufficient time to effect the sintering and substantially maximum densification of the resulting product.
Claim 2
Dependent Claim
87 words
A process for producing a dense polycrystalline ceramic ferric oxide which comprises reacting ferric ion with hydroxide ion in aqueous medium to produce a gelatinous precipitate of the corresponding hydrous oxide; separating the gelatinous precipitate from solution; heating the gelatinous precipitate up to a temperature of at least 1000° C. but below that at which decomposition occurs and at a rate effective to produce a substantially fracture-free ceramic; and maintaining said temperature for sufficient time to effect the sintering and substantially maximum densification of the resulting product.
Claim 3
Dependent Claim
70 words
A process according to claim 1 for producing a dense polycrystalline ferric oxide ceramic which comprises reacting ferric ion with hydroxide ion in aqueous medium to produce a gelatinous precipitate of hydrous ferric oxide; separating said gelatinous precipitate from solution; heating the gelatinous precipitate up to a temperature of about 1100° C. at a rate effective to produce a substantially fracturefree ceramic; and maintaining said temperature for approximately one hour.
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) | 1983-06-10 | 1983-12-10 | 1984-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-06-10 | 1987-12-10 | 1988-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-06-10 | 1991-12-10 | 1992-06-10 | $7700.00 | Window Closed / Lapsed |