US4330514A
Expired / Lapsed
US
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Hydroxyapatite, ceramic material and process for preparing thereof
Assignee: Kureha Corp
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Filing: 1980-09-19
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Granted: 1982-05-18
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Expires: 2000-09-19
Abstract
Abstract This invention relates to hydroxyapatite, ceramic material, implant material and a process for preparing thereof. The ceramic material is hydroxyapatite ceramic having an excellent thermal stability.
Inventors
- 👤 Hirosi Nagai
- 👤 Yasushi Nishimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:30
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/02; A61L27/12; A61L27/40; A61L27/44; A61L27/46; C; C01; C01B; C01B25/00; C01B25/16; C01B25/26; C01B25/32; C01B25/322; C04; C04B; C04B35/00; C04B35/01; C04B35/447; A61F; A61F2310/00; A61F2310/00005; A61F2310/00179; A61F2310/00293; Y; Y10; Y10S; Y10S623/00; Y10S623/92
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
102 words
A process for preparing hydroxyapatite, comprising the steps of, (a) converting powder calcium carbonate into calcium oxide by thermal decomposing in an inert atmosphere at a temperature of 800° to 1300° C. for 0.5 to 10 hours, (b) cooling the converted calcium oxide to a temperature lower than 500° C. in the inert atmosphere, (c) slaking the cooled calcium oxide with water while agitating in turbulent flow in an inert atmosphere thereby to obtain calcium hydroxide, (d) bringing the obtained calcium hydroxide into reaction with an aqueous solution of phosphoric acid in an inert atmosphere under turbulent flow, thereby to obtain hydroxyapatite.
Claim 2
Dependent Claim
102 words
A process for preparing hydroxyapatite, comprising the steps of, (a) converting powder calcium carbonate into calcium oxide by thermal decomposing in an inert atmosphere at a temperature of 800° to 1300° C. for 0.5 to 10 hours, (b) cooling the converted calcium oxide to a temperature lower than 500° C. in the inert atmosphere, (c) slaking the cooled calcium oxide with water while agitating in turbulent flow in an inert atmosphere thereby to obtain calcium hydroxide, (d) bringing the obtained calcium hydroxide into reaction with an aqueous solution of phosphoric acid in an inert atmosphere under turbulent flow, thereby to obtain hydroxyapatite.
Claim 3
Dependent Claim
28 words
The process according to claim 1, wherein the calcium hydroxide is brought into reaction with the aqueous solution of phosphoric acid in a state of aqueous emulsified suspension.
Claim 4
Dependent Claim
31 words
The process according to claim 1 or 2, wherein the calcium hydroxide is brought into reaction with the aqueous solution of phosphoric acid at a temperature of 0° to 50° C.
Claim 5
Dependent Claim
15 words
The process according to claim 1, wherein said inert gas is nitrogen, helium or argon.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-05-17 | 1985-11-16 | 1986-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-17 | 1989-11-16 | 1990-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-17 | 1993-11-16 | 1994-05-18 | $7700.00 | Window Closed / Lapsed |