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US5569490A Expired / Lapsed US ⏱️ 0.0 years remaining

Tetracalcium phosphate-based materials and processes for their preparation

Assignee: Sumitomo Osaka Cement Co Ltd
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Filing: 1995-06-02
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Granted: 1996-10-29
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Expires: 2015-06-02
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Abstract

Abstract The invention provides (i) a process for preparing tetracalcium phosphate particles, the process comprising the steps of (1) sintering or fusing a powder mixture at a temperature of not lower than 1,400° C., the mixture comprising a powder of calcium source and a powder of phosphorus source in a Ca/P molar ratio of 2/1, and about 0.005 to about 5 parts of an aluminum compound, calculated as Al 2 O 3 , per 100 parts of tetracalcium phosphate to be produced in terms of the theoretical amount, and (2) finely dividing the obtained product; (ii) tetracalcium phosphate particles prepared by said process; (iii) apatite-coated tetracalcium phosphate particles; (iv) a process for preparing the apatite-coated tetracalcium phosphate particles; (v) a tetracalcium phosphate-based setting composition; (vi) a composition for forming a hardening material using coated tetracalcium phosphate particles and an acidic aqueous solution; and (vii) the composition as defined in (vi) in which the acidic aqueous solution can satisfy the concentration relationships as represented below: (a) 25%≦citric acid≦50% (b) 30%≦citric acid+phosphoric acid≦70% (c) 10%≦citric acid-phosphoric acid≦50%

Inventors

  • 👤 Akitoshi Imura
  • 👤 Toru Saito
  • 👤 Shiro Ikegami

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 15:27
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/02; A61L27/12; A61K; A61K6/00; A61K6/15; A61K6/17; A61K6/80; A61K6/831; A61K6/838; A61K6/849; A61K6/864; A61K6/873; A61K6/876; A61L27/28; A61L27/30; A61L27/32; C; C01; C01B; C01B25/00; C01B25/16; C01B25/26; C01B25/32; C01B25/327; A61F; A61F2310/00; A61F2310/00005; A61F2310/00179; A61F2310/00293; A61F2310/00389; A61F2310/00592; A61F2310/00796; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 90 words
A process for preparing tetracalcium phosphate particles, the process comprising the steps of (1) sintering or fusing a powder mixture at a temperature of not lower than 1,400° C., the mixture comprising a powder of calcium source and a powder of phosphorus source in a Ca/P molar ratio of 2:1, and about 0.005 to about 5 parts of an aluminum compound, calculated as Al 2 O 3 , per 100 parts of tetracalcium phosphate to be produced in terms of the theoretical amount, and (2) finely dividing the obtained product.
Claim 2
Dependent Claim 90 words
A process for preparing tetracalcium phosphate particles, the process comprising the steps of (1) sintering or fusing a powder mixture at a temperature of not lower than 1,400° C., the mixture comprising a powder of calcium source and a powder of phosphorus source in a Ca/P molar ratio of 2:1, and about 0.005 to about 5 parts of an aluminum compound, calculated as Al 2 O 3 , per 100 parts of tetracalcium phosphate to be produced in terms of the theoretical amount, and (2) finely dividing the obtained product.
Claim 3
Dependent Claim 41 words
A process according to claim 1 wherein the calcium source and the phosphorus source are at least one member selected from the group consisting of CaHPO 4 , CaHPO 4 .2H 2 O and Ca 3 (PO 4 ) 2 .
Claim 4
Dependent Claim 14 words
A process according to claim 1 wherein the calcium source is CaCO 3 .
Claim 5
Dependent Claim 29 words
A process according to claim 1 wherein the particles of the calcium source, the phosphorous source and the aluminum compound have a particle size of up to 20 μm.
Claim 6
Dependent Claim 31 words
A process according to claim 1 wherein the particles of the calcium source, the phosphorous source and the aluminum compound have a particle size of about 5 μm on the average.
Claim 7
Dependent Claim 73 words
A process according to claim 1 wherein the aluminum compound is at least one member selected from the group consisting of Al 2 O 3 , Al(OH) 3 , Al(PO) 3 , AlPO 4 , Al(H 2 PO 4 ) 3 , AlB 2 , AlCl 3 , AlF 3 , AlI 3 , Al 2 (SiO 3 ) 3 , Al 2 (SO 4 ) 3 and Al 2 TiO 5 .
Claim 8
Dependent Claim 42 words
A process according to claim 1 wherein the amount of the aluminum compound is about 1 to about 2 parts, calculated as Al 2 O 3 , per 100 parts of tetracalcium phosphate to be produced in terms of the theoretical amount.
Claim 9
Dependent Claim 17 words
A process according to claim 1 wherein the calcining temperature is about 1,500° to about 1,550° C.
Claim 10
Dependent Claim 62 words
A process according to claim 1 wherein the aluminum compound, calculated as Al 2 O 3 , contains up to 60% of at least one member selected from the group consisting of BaSO 4 , BaCO 3 , SrSO 4 , SrCO 3 , BaSiF 6 , SnF 6 , CaF 2 , NaF, AlF 3 and Na 2 SiF 6 .
Claim 11
Dependent Claim 12 words
Tetracalcium phosphate particles prepared by the process as defined in claim 1.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1999-10-29 2000-04-29 2000-10-29 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2003-10-29 2004-04-29 2004-10-29 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2007-10-29 2008-04-29 2008-10-29 $7700.00 Window Closed / Lapsed

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