US4139599A
Expired / Lapsed
US
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Process for preparing dicalcium phosphate dihydrate having a portion of the calcium displaced by divalent metal ion
Assignee: Colgate Palmolive Co
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Filing: 1977-06-02
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Granted: 1979-02-13
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Expires: 1997-06-02
Abstract
Abstract Process for preparing dicalcium phosphate dihydrate with displacement 0.1 - 5% of the calcium by divalent metal ion.
Inventors
- 👤 Kenneth Tomlinson
- 👤 Edward J. Duff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:37
CPC Classifications
A; A61; A61K; A61K8/00; A61K8/18; A61K8/19; A61K8/24; A61Q; A61Q11/00; C; C01; C01B; C01B25/00; C01B25/16; C01B25/26; C01B25/45; C01B25/455
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
111 words
A process for preparing dicalcium phosphate dihydrate having about 0.1-5% by weight of calcium displaced by a divalent metal ion comprising reacting with a mixture of monobasic and dibasic sodium phosphate in an aqueous solution maintained no higher than pH 5, a reactant mixture selected from the group consisting of a calcium halide with non-toxic divalent metal ion halide or nitrate to form dicalcium phosphate dihydrate wherein said divalent metal ion halide or nitrate is used in amount to displace about 0.1-5% by weight of the calcium and said divalent metal ion is selected from the group consisting of zinc, copper, cadmium, nickel, cobalt, iron, manganese, chromium, magnesium, strontium and barium.
Claim 2
Dependent Claim
111 words
A process for preparing dicalcium phosphate dihydrate having about 0.1-5% by weight of calcium displaced by a divalent metal ion comprising reacting with a mixture of monobasic and dibasic sodium phosphate in an aqueous solution maintained no higher than pH 5, a reactant mixture selected from the group consisting of a calcium halide with non-toxic divalent metal ion halide or nitrate to form dicalcium phosphate dihydrate wherein said divalent metal ion halide or nitrate is used in amount to displace about 0.1-5% by weight of the calcium and said divalent metal ion is selected from the group consisting of zinc, copper, cadmium, nickel, cobalt, iron, manganese, chromium, magnesium, strontium and barium.
Claim 3
Dependent Claim
37 words
The process of claim 1 wherein said dicalcium phosphate dihydrate is dehydrated to remove water of crystallization thereby forming anhydrous dicalcium phosphate wherein about 0.1-5% by weight of the calcium is replaced by said divalent metal ion.
Claim 4
Dependent Claim
31 words
The process of claim 1 wherein said dicalcium phosphate dihydrate is calcined to form calcium pyrophosphate wherein about 0.1-5% by weight of the calcium is replaced by said divalent metal ion.
Claim 5
Dependent Claim
12 words
The process of claim 1 wherein said divalent metal ion is zinc.
Claim 6
Dependent Claim
19 words
The process of claim 1 wherein halide of said calcium and said non-toxic divalent metal ion halide is chloride.
Claim 7
Dependent Claim
21 words
The process of claim 1 wherein said aqueous solution is maintained at a pH of from about 4 to about 5.
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) | 1982-02-12 | 1982-08-14 | 1983-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-12 | 1986-08-14 | 1987-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-12 | 1990-08-14 | 1991-02-13 | $7700.00 | Window Closed / Lapsed |