Method for preparing a microencapsulated compound of a platinum group metal
AssigneeDow Corning Corporation
InventorsChi-Long Lee, Robin L. Willis, Jr.
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Abstract
Compounds of metals from the platinum group of the periodic table compounds are encapsulated within a thermoplastic organic polymer using known prior art techniques. The presence of trace amounts of the encapsulated compound on the surface of the microcapsules is avoided by preparing the microcapsules by in-situ polymerization or precipitation of the encapsulant, followed by washing of the microcapsules with a solvent for the encapsulated compound that will not dissolve or swell the encapsulating polymer.
Claims8
In a method for preparing a microencapsulated compound, said method comprising the following sequence of steps:
- A. dispersing said compound in finely divided form in a fluid medium;
- B. introducing into said medium a liquified thermoplastic organic polymer or a liquified precursor of said polymer, where said polymer is impervious to said compound,
- C. depositing a solid coating of said polymer around each particle of said compound in an amount equal to at least 50 percent of the combined weight of said compound and said coating, and
- D. recovering the resultant microencapsulated compound,
- the improvement comprising (1) selecting said compound from compounds of platinum group metals and (2) washing the recovered microencapsulated compound with a liquid that is a solvent for said compound but not for said polymer.
Dependencies are inferred from the claim text.