Method for forming a non-hygroscopic zinc-phosphate compound and a zinc-phosphate glass
US5482526A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 17, 1994 |
| Grant date | Jan 9, 1996 |
| Priority date | — |
| Expiry date | Feb 17, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C3/16
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The instant invention describes a method for preparing a stable, anhydrous non-hygroscopic zinc phosphate compound which is suitable for use as a batch material in the preparation of zinc-phosphate glasses. This method comprises three basic steps: first, forming an aqueous slurry mixture by intimately mixing a mixture containing phosphoric acid and a zinc-containing compound whereby the so-formed slurry mixture is comprised of a mixture of zinc hydrogen phosphates and exhibits a P.sub.2 O.sub.5 /ZnO weight ratio range between about 1.2 to 2.0; second, heating the so-formed slurry mixture to a temperature and for a time sufficient to achieve both a removal of a sufficient amount of water and the phase transformation of the zinc hydrogen phosphates resulting in zinc-phosphate material comprised of granular solid mixture of zinc metaphosphates and zinc pyrophosphate and third, cooling the zinc-phosphate material to room temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.