Method for protecting a porous carbon-containing material from oxidation, and material obtained thereby
US5714244A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 1995 |
| Grant date | Feb 3, 1998 |
| Priority date | — |
| Expiry date | Nov 30, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/30
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A material is impregnated with an aqueous solution containing precursors of a glass-containing phosphate base modified at least by the presence of zinc oxide, then dried and heat treated to form an internal oxidation protection constituted by the modified phosphate glass-containing base. The precursors are introduced into the aqueous solution so as to form a glass-containing base in which the molar ratio between the glass modifying oxides, comprising zinc oxide, and the glass forming oxides, principally comprising or consisting of phosphoric anhydride, is sufficiently high, in particular at least 0.6, preferably 0.9, to confer a resistance to corrosion by moisture on the glass-containing phosphate base. The solution is formed by first dissolving in water, a polyphosphate such as sodium metaphosphate or trimetaphosphate which can allow the subsequent dissolution, by stable complexing without forming a precipitate, of the required quantity of precursor salts for the modifying oxides comprising at least one zinc salt such as zinc nitrate or sulfate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.