US5215941A
Expired / Lapsed
US
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Process for producing a sintered apatite article having a porous surface using an acidic buffer solution
Assignee: Pentax Corp
•
Filing: 1992-01-15
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Granted: 1993-06-01
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Expires: 2012-01-15
Abstract
Abstract A process for producing a sintered apatite article having a porous surface by contacting a dense sintered apatite article with an acidic buffer solution, provided that the acidic buffer solution does not contain phosphoric acid.
Inventors
- 👤 Fumie Yasukawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:45
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/53; C04B41/5338; C04B41/5353; A; A61; A61L; A61L27/00; A61L27/02; A61L27/12; C04B41/80; C04B41/91; A61F; A61F2310/00; A61F2310/00005; A61F2310/00179; A61F2310/00293
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
51 words
A process for producing a sintered article having a porous surface, which sintered article consists essentially of apatite, which comprises the step of: contacting a dense sintered article, which sintered article consists essentially of apatite, with an acidic buffer solution, provided that said acidic buffer solution does not contain phosphoric acid.
Claim 2
Dependent Claim
51 words
A process for producing a sintered article having a porous surface, which sintered article consists essentially of apatite, which comprises the step of: contacting a dense sintered article, which sintered article consists essentially of apatite, with an acidic buffer solution, provided that said acidic buffer solution does not contain phosphoric acid.
Claim 3
Dependent Claim
19 words
A process as claimed in claim 1, wherein said acidic buffer solution has a pH of 6.0 or less.
Claim 4
Dependent Claim
20 words
A process as claimed in claim 2, wherein said acidic buffer solution has a pH of from 2.2 to 6.0.
Claim 5
Dependent Claim
20 words
A process as claimed in claim 3, wherein said acidic buffer solution has a pH of from 2.2 to 3.5.
Claim 6
Dependent Claim
30 words
A process as claimed in claim 1, wherein said dense sintered apatite article consists essentially of at least one apatite selected from the group consisting of hydroxyapatite, fluoroapatite, and chloroapatite.
Claim 7
Dependent Claim
38 words
A process as claimed in claim 1, wherein said acidic buffer solution is selected from the group consisting of a citric acid based buffer solution, a hydrochloric acid based buffer solution, and a phthalic acid based buffer solution.
Claim 8
Dependent Claim
22 words
A process as claimed in claim 1, wherein the apatite constituting the dense sintered article has a Ca/P molar ratio of 1.67.
References Cited (Backward Citations)
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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) | 1996-05-31 | 1996-11-30 | 1997-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-31 | 2000-11-30 | 2001-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-31 | 2004-11-30 | 2005-06-01 | $7700.00 | Window Closed / Lapsed |