Patent US3444323A successfully refreshed from Google Patents.
US5077079A
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Method for formation of calcium phosphate compound coating on surface of ceramic article
Assignee: National Institute of Advanced Industrial Science and Technology
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Filing: 1991-02-08
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Granted: 1991-12-31
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Expires: 2011-02-08
Abstract
Abstract A dense coating of a calcium phosphate compound is formed on the surface of a bioadaptable ceramic substrate by applying to the ceramic calcium metaphosphate alone or a mixture of calcium metaphosphate with calcium pyrophosphate, heat-treating the applied layer thereby fusing the applied layer to the surface of the ceramic, then applying to the fused layer a slurry resulting from the mixture of calcium metaphosphate with tetracalcium phosphate, and subsequently heat-treating the applied layer of the slurry thereby inducing reaction of the slurry.
Inventors
- 👤 Sukezo Kawamura
- 👤 Yoshiyuki Yokogawa
- 👤 Yukari Kawamoto
- 👤 Motohiro Toriyama
- 👤 Takahiro Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:46
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; A; A61; A61L; A61L27/00; A61L27/28; A61L27/30; A61L27/32; C04B41/45; C04B41/50; C04B41/5076; C04B41/5092; C04B41/80; C04B41/81; C04B41/85; A61F; A61F2310/00; A61F2310/00389; A61F2310/00592; A61F2310/00796; C04B2111/00; C04B2111/00474; C04B2111/00836
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
133 words
A method for forming on the surface of a ceramic substrate a dense coating composed of at least one member selected from the group consisting of β-tricalcium phosphate and calcium hydroxy apatite, which comprises the steps of: applying to the surface of a ceramic substrate at least one compound selected from the group consisting of calcium metaphosphate and a mixture of calcium metaphosphate and calcium pyrophosphate; heating the applied compound, thereby fusing the compound to the surface of said ceramic substrate; applying to the fused compound a slurry consisting of a mixture of calcium metaphosphate and tetracalcium phosphate; and subsequently heating the applied slurry, thereby inducing reaction of the slurry to form a dense coating composed of at least one member selected from the group consisting of β-tricalcium phosphate and calcium hydroxy apatite.
Claim 2
Independent Claim
133 words
A method for forming on the surface of a ceramic substrate a dense coating composed of at least one member selected from the group consisting of β-tricalcium phosphate and calcium hydroxy apatite, which comprises the steps of: applying to the surface of a ceramic substrate at least one compound selected from the group consisting of calcium metaphosphate and a mixture of calcium metaphosphate and calcium pyrophosphate; heating the applied compound, thereby fusing the compound to the surface of said ceramic substrate; applying to the fused compound a slurry consisting of a mixture of calcium metaphosphate and tetracalcium phosphate; and subsequently heating the applied slurry, thereby inducing reaction of the slurry to form a dense coating composed of at least one member selected from the group consisting of β-tricalcium phosphate and calcium hydroxy apatite.
Claim 3
Dependent Claim
37 words
A method according to claim 1, wherein said at least one compound applied to the surface of the ceramic substrate is calcium metaphosphate and is heated at a temperature in the range of 900° to 1,100° C.
Claim 4
Dependent Claim
43 words
A method according to claim 1, wherein said at least one compound applied to the surface of the ceramic substrate is a mixture of calcium metaphosphate and calcium pyrophosphate and is heated at a temperature in the range of 1,100° to 1,280° C.
Claim 5
Dependent Claim
25 words
A method according to claim 3, wherein the gravimetric mixing ratio of calcium metaphosphate to calcium pyrophosphate is in the range of 3:7 to 7:3.
Claim 6
Dependent Claim
38 words
A method according to claim 1, wherein the heat treatment given to the applied layer of the slurry consisting of calcium metaphosphate and tetracalcium phosphate is performed at a temperature in the range of 1,200° to 1,350° C.
Claim 7
Dependent Claim
29 words
A method according to claim 1, wherein the atomic ratio of calcium metaphosphate and tetracalcium phosphate in the applied slurry Ca/P, is in the range of 1.4:1 to 1.75:1.
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) | 1994-12-30 | 1995-07-01 | 1995-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-30 | 1999-07-01 | 1999-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-30 | 2003-07-01 | 2003-12-31 | $7700.00 | Window Closed / Lapsed |