High viscosity potassium metaphosphate
US4824649A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 31, 1987 |
| Grant date | Apr 25, 1989 |
| Priority date | — |
| Expiry date | Aug 31, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B25/445
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
An improved process for preparing potassium metaphosphate is provided which comprises reacting potassium ions, preferably from the carbonate or bicarbonate, with phosphare ions in an amount sufficient to provide a K/P molar ratio ranging from about 0.85 to about 0.95 substantially in the absence of metal ion other than potassium under heat for a period of time and at a temperature sufficient to convert the potassium and phosphate ions to potassium metaphosphate but insufficient to overconvert. A product of higher viscosity can be obtained by dissolving the potassium metaphosphate in sodium bicarbonate rather than using other sources of sodium ion, particularly when the potassium metaphosphate is prepared with potassium bicarbonate or potassium carbonate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.