US4897250A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing calcium phosphate
Assignee: Pentax Corp
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Filing: 1989-01-25
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Granted: 1990-01-30
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Expires: 2009-01-25
Abstract
Abstract A process for producing a calcium phosphate comprising the steps of (a) dissolving at least one member selected from the group consisting of calcium hydroxide and calcium oxide in water with at least one member selected from the group consisting of a sugar, a sugar alcohol, and a polyhydric alcohol; (b) and adding phosphoric acid to the solution obtained to precipitate a calcium phosphate.
Inventors
- 👤 Masaya Sumita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 07:54
CPC Classifications
C; C01; C01B; C01B25/00; C01B25/16; C01B25/26; C01B25/32; C01B25/322; C01B25/455
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
91 words
A process for producing a calcium phosphate comprising the steps of (a) dissolving at least one first member selected from the group consisting of calcium hydroxide and calcium oxide in water with at least one second member selected from the group consisting of a sugar, a sugar alcohol, and a polyhydric alcohol, said at least one second member present in a total concentration effective to increase the solubility of the calcium hydroxide or calcium oxide in water; (b) and adding phosphoric acid to the solution obtained to precipitate a calcium phosphate.
Claim 2
Dependent Claim
91 words
A process for producing a calcium phosphate comprising the steps of (a) dissolving at least one first member selected from the group consisting of calcium hydroxide and calcium oxide in water with at least one second member selected from the group consisting of a sugar, a sugar alcohol, and a polyhydric alcohol, said at least one second member present in a total concentration effective to increase the solubility of the calcium hydroxide or calcium oxide in water; (b) and adding phosphoric acid to the solution obtained to precipitate a calcium phosphate.
Claim 3
Dependent Claim
34 words
A process for producing a calcium phosphate as claimed in claim 1, wherein said sugar is selected from the group consisting of glucose, fructose, galactose, maltose, saccharose, mannose, sorbose, ribose, xylose, arabinose, and lactose.
Claim 4
Dependent Claim
26 words
A process for producing a calcium phosphate as claimed in claim 1, wherein said sugar alcohol is selected from the group consisting of sorbitol and mannitol.
Claim 5
Dependent Claim
26 words
A process for producing a calcium phosphate as claimed in claim 1, wherein said polyhydric alcohol is selected from the group consisting of glycerin and erythritol.
Claim 6
Dependent Claim
39 words
A process for producing a calcium phosphate as claimed in claim 1, wherein said step (a) comprises first preparing an aqueous solution of said sugar, sugar alcohol, or polyhydric alcohol, and thereafter adding said calcium hydroxide or calcium oxide
Claim 7
Dependent Claim
45 words
A process for producing a calcium phosphate as claimed in claim 1, wherein said step (a) comprises first adding said calcium hydroxide or calcium oxide to water to prepare lime milk, and thereafter adding said sugar, sugar alcohol, or polyhydric alcohol to said lime milk.
Claim 8
Dependent Claim
35 words
A process for producing a calcium phosphate as claimed in claim 1, wherein said step (a) comprises simultaneously adding said sugar, sugar alcohol, or polyhydric alcohol, and said calcium hydroxide or calcium oxide to water.
Claim 9
Dependent Claim
32 words
A process for producing a calcium phosphate as claimed in claim 1, wherein the total concentration of said sugar, sugar alcohol, or polyhydric alcohol in said solution is at least 10 wt%.
Claim 10
Dependent Claim
49 words
A process for producing a calcium phosphate as claimed in claim 1, wherein said calcium phosphate is selected from the group consisting of Ca 10 (PO 4 ) 6 (OH) 2 , Ca 10 (PO 4 ) 6 F 2 , and Ca 3 (PO 4 ) 2 .
Claim 11
Dependent Claim
19 words
A process for producing a calcium phosphate as claimed in claim 1, wherein said first member is calcium hydroxide.
Claim 12
Dependent Claim
19 words
A process for producing a calcium phosphate as claimed in claim 1, wherein said first member is calcium oxide.
References Cited (Backward Citations)
FI21988A
Cited
US1929443A
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FR2419254A1
Cited
GB1586915A
Cited
US4265867A
Cited
JPS5921509A
Cited
FR2537558A1
Cited
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JPS59217610A
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EP0205622A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-01-29 | 1993-07-31 | 1994-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-29 | 1997-07-31 | 1998-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-29 | 2001-07-31 | 2002-01-30 | $7700.00 | Window Closed / Lapsed |