US4308064A
Expired / Lapsed
US
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Phosphate of calcium ceramics
Assignee: Niterra Co Ltd
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Filing: 1980-07-23
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Granted: 1981-12-29
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Expires: 2000-07-23
Abstract
Abstract A strong and biocompatible sintered phosphate of calcium ceramics are obtained by sintering a powdery material substantially consisting of phosphate of calcium having a Ca/P ratio of 1.4-1.75, e.g. apatite group and/or tricalcium phosphate, and not exceeding 15% by weight of CaO-P 2 O 5 frit having a Ca/P ratio of 0.2-0.75. Y 2 O 3 incorporation therein improves the bending strength of the ceramics. Furthermore, a P 2 O 5 -metal oxide frit wherein metal oxide being one or more selected from BaO, CaO, MgO, ZnO, NaO and K 2 O provides a more improved bending strength. The Y 2 O 3 incorporation herein still improves the strength of the sintered product.
Inventors
- 👤 Akio Takami
- 👤 Kazuo Kondo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:42
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: 28
Claim 1
Independent Claim
85 words
Phosphate of calcium ceramics obtained by sintering a ceramic material consisting essentially of 3-23% by weight of Y 2 O 3 , 0.5-15% by weight of CaO-P 2 O 5 frit having a Ca/P atomic ratio in the range of 0.70-0.75, both calculated for the ceramics, and the balance of a powdery material substantially consisting of phosphate of calcium having a Ca/P atomic ratio of 1.4-1.75, and being of improved bending strength over ceramics otherwise the same but not containing Y 2 O 3 .
Claim 2
Dependent Claim
85 words
Phosphate of calcium ceramics obtained by sintering a ceramic material consisting essentially of 3-23% by weight of Y 2 O 3 , 0.5-15% by weight of CaO-P 2 O 5 frit having a Ca/P atomic ratio in the range of 0.70-0.75, both calculated for the ceramics, and the balance of a powdery material substantially consisting of phosphate of calcium having a Ca/P atomic ratio of 1.4-1.75, and being of improved bending strength over ceramics otherwise the same but not containing Y 2 O 3 .
Claim 3
Dependent Claim
24 words
The ceramics of claim 1 wherein said powdery material substantially consisting of phosphate of calcium is apatite group, tricalcium phosphate or a mixture thereof.
Claim 4
Dependent Claim
18 words
The ceramics of claim 2 wherein said apatite group is synthetic or natural apatite or a mixture thereof.
Claim 5
Dependent Claim
27 words
The ceramics of claim 3 wherein said apatite group essentially consists of apatite represented by a formula Ca 5 (OH, F, Cl) (PO 4 ) 3 .
Claim 6
Dependent Claim
31 words
The ceramics of claim 4 wherein said apatite group is a synthetic apatite produced by precipitation process, dry process, hydrothermal process or molten process, or a mixture of said synthetic apatites.
Claim 7
Dependent Claim
28 words
The ceramics of claim 2 wherein said apatite group is synthetic hydroxyapatite having a Ca/P atomic ratio of 1.4-1.75 produced by precipitation process, dry process or hydrothermal process.
Claim 8
Dependent Claim
23 words
The ceramics of claim 1 wherein said powdery material substantially consisting of phosphate or calcium is hydroxyapatite, tricalcium phosphate or a mixture thereof.
Claim 9
Dependent Claim
39 words
The ceramics of claim 1 wherein said CaO-P 2 O 5 frit comprises approximately 0-10 mol% calculated for the frit of SiO 2 and/or Al 2 O 3 and the balance of CaO and P 2 O 5 .
Claim 10
Dependent Claim
48 words
The ceramics of claim 1 wherein the ceramics comprise impurities not exceeding approximately 0.5% by weight calculated for the ceramics originating from the frit, which impurities comprise SiO 2 , Al 2 O 3 , B 2 O 3 , TiO 2 and/or Fe 2 O 3 .
Claim 11
Dependent Claim
15 words
The ceramics of claim 1, obtained by sintering the ceramic material at approximately 1000°-1500° C.
Claim 12
Dependent Claim
26 words
The ceramics of claim 1, wherein said frit is prepared by melting the components of said frit at approximately 1300°-1400° C., then comminuting the resultant frit.
Claim 13
Dependent Claim
26 words
The ceramics of claim 1, wherein the oxide or chloride of yttrium or mixture thereof is used as a source for Y 2 O 3 .
Claim 14
Dependent Claim
176 words
Phosphate of calcium ceramics obtained by sintering a ceramic material consisting essentially of 3-23% by weight of Y 2 O 3 , 0.5-15% by weight of P 2 O 5 -metal oxide frit, both calculated for the ceramics, and the balance of a powdery material consisting essentially of phosphate of calcium having a Ca/P atomic ratio of 1.4-1.75, the P 2 O 5 -metal oxide frit consisting essentially of, in mol% calculated for the frit, 40-75% P 2 O 5 and 20-55% of one or more metal oxide selected from the group consisting of BaO, CaO, MgO, ZnO, Na 2 O and K 2 O, provided that the sum of said P 2 O 5 and said metal oxide is not less than 90 mol% in the frit and said P 2 O 5 -metal oxide frit in mol% comprises 0-55% BaO, 0-55% CaO, 0-20% MgO, 0-20% ZnO, 0-20% Na 2 O and 0-20% K 2 O, and being of improved bending strength over ceramics otherwise the same but not containing Y 2 O 3 .
Claim 15
Dependent Claim
176 words
Phosphate of calcium ceramics obtained by sintering a ceramic material consisting essentially of 3-23% by weight of Y 2 O 3 , 0.5-15% by weight of P 2 O 5 -metal oxide frit, both calculated for the ceramics, and the balance of a powdery material consisting essentially of phosphate of calcium having a Ca/P atomic ratio of 1.4-1.75, the P 2 O 5 -metal oxide frit consisting essentially of, in mol% calculated for the frit, 40-75% P 2 O 5 and 20-55% of one or more metal oxide selected from the group consisting of BaO, CaO, MgO, ZnO, Na 2 O and K 2 O, provided that the sum of said P 2 O 5 and said metal oxide is not less than 90 mol% in the frit and said P 2 O 5 -metal oxide frit in mol% comprises 0-55% BaO, 0-55% CaO, 0-20% MgO, 0-20% ZnO, 0-20% Na 2 O and 0-20% K 2 O, and being of improved bending strength over ceramics otherwise the same but not containing Y 2 O 3 .
Claim 16
Dependent Claim
16 words
The ceramics of claim 13, wherein the metal oxide in said frit consists essentially of CaO.
Claim 17
Dependent Claim
17 words
The ceramics of claim 14, wherein said frit consists essentially of P 2 O 5 and CaO.
Claim 18
Dependent Claim
24 words
The ceramics of claim 13 wherein said powdery material substantially consisting of phosphate of calcium is apatite group, tricalcium phosphate or a mixture thereof.
Claim 19
Dependent Claim
18 words
The ceramics of claim 16 wherein said apatite group is synthetic or natural apatite or a mixture thereof.
Claim 20
Dependent Claim
27 words
The ceramics of claim 17 wherein said apatite group essentially consists of apatite represented by a formula Ca 5 (OH, F, Cl) (PO 4 ) 3 .
Claim 21
Dependent Claim
30 words
The ceramics of claim 18 wherein said apatite group is synthetic apatite produced by precipitation process, dry process, hydrothermal process or molten process, or a mixture of said synthetic apatites.
Claim 22
Dependent Claim
28 words
The ceramics of claim 16 wherein said apatite group is synthetic hydroxyapatite having a Ca/P atomic ratio of 1.4-1.75 produced by precipitation process, dry process or hydrothermal process.
Claim 23
Dependent Claim
23 words
The ceramics of claim 13 wherein said powdery material substantially consisting of phosphate of calcium is hydroxyapatite, tricalcium phosphate or a mixture thereof.
Claim 24
Dependent Claim
42 words
The ceramics of claim 13 wherein said P 2 O 5 -metal oxide further frit comprises approximately 0-10 mol% calculated for the frit of SiO 2 and/or Al 2 O 3 and the balance of CaO and P 2 O 5 .
Claim 25
Dependent Claim
48 words
The ceramics of claim 13 wherein the ceramics comprise impurities not exceeding approximately 0.5% by weight calculated for the ceramics originating from the frit, which impurities comprise SiO 2 , Al 2 O 3 , B 2 O 3 , TiO 2 and/or Fe 2 O 3 .
Claim 26
Dependent Claim
15 words
The ceramics of claim 13, obtained by sintering the ceramic material at approximately 1000°-1500° C.
Claim 27
Dependent Claim
26 words
The ceramics of claim 13, wherein said frit is prepared by melting the components of said frit at approximately 1300°-1400° C., then comminuting the resultant frit.
Claim 28
Dependent Claim
27 words
The ceramics of claim 13, wherein the oxide or chloride of yttrium or a mixture thereof is used as a source for Y 2 O 3 .
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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) | 1984-12-28 | 1985-06-29 | 1985-12-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-28 | 1989-06-29 | 1989-12-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-28 | 1993-06-29 | 1993-12-29 | $7700.00 | Window Closed / Lapsed |