出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2016/03/17 14:53:57」(JST)
| Names | |
|---|---|
| IUPAC name
Calcium hydrogen phosphate dihydrate
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| Other names
Calcium monohydrogen phosphate
Phosphoric acid, calcium salt (1:1) |
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| Identifiers | |
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CAS Number
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7757-93-9 Y 7789-77-7 (dihydrate) N |
| ChemSpider | 94606 N |
| Jmol interactive 3D | Image |
| PubChem | 104805 |
| UNII | L11K75P92J Y |
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InChI
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SMILES
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| Properties | |
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Chemical formula
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CaHPO4 |
| Molar mass | 136.06 g/mol (anhydrous) 172.09 (dihydrate) |
| Appearance | white powder |
| Odor | odorless |
| Density | 2.929 g/cm3 (anhydrous) 2.31 g/cm3 (dihydrate) |
| Melting point | decomposes |
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Solubility in water
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0.02 g/100 mL (anhydrous) 0.02 g/100 mL (dihydrate) |
| Structure | |
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Crystal structure
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triclinic |
| Hazards | |
| NFPA 704 |
0
1
0
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| Flash point | Non-flammable |
| Related compounds | |
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Other anions
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Calcium pyrophosphate |
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Other cations
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Magnesium phosphate Monocalcium phosphate |
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Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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| N verify (what is YN ?) | |
| Infobox references | |
Dicalcium phosphate is a misnomer for dibasic calcium phosphate. Its chemical formula is CaHPO4. Hence the name "dicalcium" is incorrect. The correct names of this material are dibasic calcium phosphate or calcium monohydrogen phosphate. There are three crystalline forms: a dihydrate, CaHPO4•2H2O ('DPCD'), the mineral brushite; a hemihydrate, CaHPO4•0.5H2O; and anhydrous CaHPO4 ('DCPA'), the mineral monetite. Below pH 4.8 the dihydrate and anhydrous forms of dibasic calcium phosphate are the most stable (insoluble) of the calcium phosphates. Dibasic calcium phosphate is used as a food additive, it is found in some toothpastes as a polishing agent and is a biomaterial.[1][2] In the dihydrate (brushite) form it is found in some kidney stones and in dental calculi.[3][4]
Dibasic calcium phosphate is produced by the reaction of calcium chloride and phosphoric acid:[citation needed]
Calcium hydroxide is also used in place of the calcium chloride and sodium hydroxide. The room temperature neutralisation of phosphoric acid with calcium hydroxide at pH 3-4 precipitates the dihydrate. At 60°C the anhydrous form is precipitated:[4]
One industrial preparation of the dihydrate involves the reaction of H3PO4 with a slurry of Ca(OH)2 below 40°C. To prevent degradation that would form hydroxyapatite, Sodium pyrophosphate or trimagnesium phosphate octahydrate are added when for example, dibasic calcium phosphate dihydrate is to be used as a polishing agent in toothpaste.[1]
Anhydrous CaHPO4 is an intermediate in the production of halophosphate phosphors that were used in fluorescent lamps. In a continuous process CaCl2 was reacted with (NH4)2HPO4 to form the dihydrate, CaHPO4•2H2O.
A slurry of the dihydrate is then heated to around 65–70°C to form anhydrous CaHPO4 as a crystalline precipitate in the desired form, (typically a flat diamond shaped crystal, 7-9 μm), which was suitable for further processing.[5]
Dibasic calcium phosphate dihydrate is formed in "brushite" calcium phosphate cements (CPC's) which have medical applications. An example of the overall setting reaction in the formation of "β-TCP/MCPM" (β-tricalcium phosphate/monocalcium phosphate) calcium phosphate cements is:[6]
Dibasic calcium phosphate is mainly used as a dietary supplement in prepared breakfast cereals, dog treats, enriched flour, and noodle products. It is also used as a tableting agent in some pharmaceutical preparations, including some products meant to eliminate body odor. Dibasic calcium phosphate is also found in some dietary calcium supplements (e.g. Bonexcin). It is used in poultry feed. It is also used in some toothpastes as a tartar control agent.[7]
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| リンク元 | 「リン酸水素カルシウム」「dicalcium phosphate anhydrous」「dibasic calcium phosphate」「anhydrous dibasic calcium phosphate」 |
| 関連記事 | 「phosphate」「calcium」 |