US4767583A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing molded bodies from hydroxyphosphate
Assignee: US Philips Corp
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Filing: 1986-06-19
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Granted: 1988-08-30
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Expires: 2006-06-19
Abstract
Abstract In dental surgery and orthopedic surgery, implants of the bio-compatible hydroxyphosphate are used. Molded bodies or a granulate thereof are obtained by sintering in a moist oxygen atmosphere. These products are of a blue color. In accordance with the invention, white products are obtained by sintering in an inert atmosphere in which the oxygen concentration is maximally 0.005%.
Inventors
- 👤 Aant B. D. van der Meer
- 👤 Petrus H. Swaanen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:19
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/02; A61L27/12; C; C04; C04B; C04B35/00; C04B35/01; C04B35/447; A61F; A61F2310/00; A61F2310/00005; A61F2310/00179; A61F2310/00293
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
94 words
A method of manufacturing molded bodies of a granulate from calcium hydroxyphosphate by sintering a shaped starting material consisting essentially of a mixture of said phosphate and a dispersed organic bonder, in a water-vapor containing atmosphere at a temperature of between 1200° and 1300° C., characterized in that the sintering operation is carried out in an atmosphere consisting essentially of an inert gas in which free oxygen is present in a concentration of maximally 0.005%, and having a moisture content which, dependent upon the selected sintering temperature, ranges from 1.66 to 72.6 mm Hg.
Claim 2
Independent Claim
94 words
A method of manufacturing molded bodies of a granulate from calcium hydroxyphosphate by sintering a shaped starting material consisting essentially of a mixture of said phosphate and a dispersed organic bonder, in a water-vapor containing atmosphere at a temperature of between 1200° and 1300° C., characterized in that the sintering operation is carried out in an atmosphere consisting essentially of an inert gas in which free oxygen is present in a concentration of maximally 0.005%, and having a moisture content which, dependent upon the selected sintering temperature, ranges from 1.66 to 72.6 mm Hg.
Claim 3
Dependent Claim
21 words
A method as claimed in claim 1, characterized in that nitrogen is used as the inert atmosphere for the sintering operation.
Claim 4
Dependent Claim
99 words
A method of manufacturing porous moulded bodies from a shaped starting material as claimed in claim 1, characterized in that the shaped starting material, among which an organic binder has been dispersed, is first heated in an oxygen containing atmosphere until all of the organic matter is combusted and/or evaporated without leaving any residue, before it is sintered at a temperature between 1200° and 1300° C. in an inert water-vapour containing atmosphere having a moisture content which, dependent upon the selected sintering temperature, ranges from 1.66 to 72.6 mm Hg and in which maximally 0.005% of oxygen is present.
Claim 5
Independent Claim
84 words
A method for the conversion of a white colored product from a blue colored product made by sintering, in a water-vapor and oxygen containing atmosphere compositions essentially consisting of calcium hydroxyphosphate, said method comprising resintering the resultant blue colored product at a temperature of between 1200° C. and 1300° C. in an atmosphere consisting essentially of an inert gas and containing maximally 0.005% of free oxygen and having a moisture content of from 1.66 to 12.6 mm Hg depending on the sintering temperature employed.
Claim 6
Independent Claim
84 words
A method for the conversion of a white colored product from a blue colored product made by sintering, in a water-vapor and oxygen containing atmosphere compositions essentially consisting of calcium hydroxyphosphate, said method comprising resintering the resultant blue colored product at a temperature of between 1200° C. and 1300° C. in an atmosphere consisting essentially of an inert gas and containing maximally 0.005% of free oxygen and having a moisture content of from 1.66 to 12.6 mm Hg depending on the sintering temperature employed.
References Cited (Backward Citations)
US4149893A
Cited
JPS55130854A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-30 | 1992-02-29 | 1992-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-30 | 1996-02-29 | 1996-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-30 | 2000-02-29 | 2000-08-30 | $7700.00 | Window Closed / Lapsed |