US4157378A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing fluorapatite
Assignee: Colgate Palmolive Co
•
Filing: 1977-06-02
•
Granted: 1979-06-05
•
Expires: 1997-06-02
Abstract
Abstract The process of preparing analytically pure fluorapatite comprising reacting dicalcium phosphate dihydrate with hydrogen fluoride in aqueous solution, at a pH of from about 5 to about 8, at from about room temperature for about 7 days to about 100 DEG C. for about 2 days, the amount of fluoride ion being from about stoichiometric to about 1.1 times the stoichiometric amount of dicalcium phosphate dihydrate whereby solid analytically pure fluorapatite is formed.
Inventors
- 👤 Kenneth Tomlinson
- 👤 Edward J. Duff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:10
CPC Classifications
A; A61; A61Q; A61Q11/00; A61K; A61K8/00; A61K8/18; A61K8/19; A61K8/20; A61K8/21; A61K8/24; C; C01; C01B; C01B25/00; C01B25/16; C01B25/26; C01B25/45; C01B25/455
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
72 words
The process of preparing analytically pure fluorapatite comprising reacting dicalcium phosphate dihydrate with hydrogen fluoride in aqueous solution, at a pH of from about 5 to about 8, at from about room temperature for about 7 days to about 100° C. for about 2 days, the amount of fluoride ion being from about stoichiometric to about 1.1 times the stoichiometric amount of dicalcium phosphate dihydrate whereby solid analytically pure fluorapatite is formed.
Claim 2
Dependent Claim
72 words
The process of preparing analytically pure fluorapatite comprising reacting dicalcium phosphate dihydrate with hydrogen fluoride in aqueous solution, at a pH of from about 5 to about 8, at from about room temperature for about 7 days to about 100° C. for about 2 days, the amount of fluoride ion being from about stoichiometric to about 1.1 times the stoichiometric amount of dicalcium phosphate dihydrate whereby solid analytically pure fluorapatite is formed.
Claim 3
Dependent Claim
21 words
The process of preparing analytically pure fluorapatite claimed in claim 1 wherein said pH is from about 5.5 to about 7.
Claim 4
Dependent Claim
17 words
The process of preparing analytically pure fluorapatite claimed in claim 2 wherein said pH is about 6.5.
References Cited (Backward Citations)
US2555656A
Cited
US3505012A
Cited
GB1314094A
Cited
US3679360A
Cited
US3737516A
Cited
SU512171A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-06-04 | 1982-12-04 | 1983-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-06-04 | 1986-12-04 | 1987-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-06-04 | 1990-12-04 | 1991-06-05 | $7700.00 | Window Closed / Lapsed |