Processes for preparing mixed metal oxide powders
AssigneeWaltraud M. Kriven
InventorsMehmet Ali Gülgün, Waltraud M. Kriven, My Hoang Nguyen
Life of this patent
Estimating the term…
Abstract
Described are preferred polymerized organic-inorganic processes for producing mixed metal oxide powders suitable for use in the ceramics and related industries. The preferred processes employ a non-chelating polymer such as polyvinyl alcohol or polyalkylene glycol as a carrier and can provide single-phase, mixed oxide powders in high yields at relatively low temperatures.
Claims25
A process for preparing a mixed metal oxide powder, said process comprising:
- forming a liquid solution containing cations of at least two different metal species and a non-chelating polymer containing partially negatively charged functional groups, wherein said solution contains a molar excess of the cations relative to the partially negatively charged functional groups on the polymer;
- removing liquid from said solution to form a solid precursor material having the cations homogeneously distributed therein;
- and
- calcining said solid precursor material to form a mixed metal oxide powder.
A process for preparing a mixed metal oxide powder, said process comprising:
- forming a homogeneous liquid solution containing cations of at least two different metal species and a non-chelating polymer wherein the non-chelating polymer is formed in situ with the cations;
- removing liquid from said mixture to form a solid precursor material having the cations homogeneously distributed therein;
- and
- calcining said solid precursor material to form a mixed metal oxide powder.
A process for preparing a powder of a metal oxide containing at least two different metal species in a specified stoichiometric ratio, said process comprising:
- providing a solution comprising a solvent, cations of said at least two metals metal species dissolved in the solvent in said stoichiometric ratio, and a carrier polymer dissolved in the solvent said carrier polymer having partially negatively charged functional groups, wherein the molar ratio of cationic valences of the cations of the at least two metals to the partially negatively charged functional groups of the carrier polymer is about 4:1 to about 12:1;
- removing the solvent from said solution to form an organometallic precursor gel having the cations homogeneously distributed therein;
- and
- calcining said organometallic precursor gel to form the powder.
A process for preparing a metal oxide powder, said process comprising:
- dissolving a non-chelating polymer having negatively charged function groups and a molar excess of cations of at least two metals relative to the negatively charged functional groups of the polymer in a solvent to form a liquid precursor;
- forming a solid organometallic precursor from the liquid precursor having the cations sterically entrapped homogeneously therein by the polymer;
- and
- calcining said organometallic precursor to form an amorphous metal oxide powder.
A process for preparing a mixed metal oxide powder, said process comprising:
- forming a homogeneous liquid solution containing cations of at least two different metal species and a non-chelating polymer containing partially negatively charged functional groups, wherein said mixture contains a stoichiometric excess of the cations relative to the number of monomer units of the non-chelating polymer;
- removing liquid from said solution to form a solid precursor material having the cations homogeneously distributed therein;
- and
- calcining said solid precursor material to form a mixed metal oxide powder.
A process for preparing a mixed metal oxide powder, said process comprising:
- dissolving cations of at least two different metal species and a non-chelating polymer containing partially negatively charged functional groups in a liquid to provide a clear solution, wherein said solution contains a molar excess of the cations relative to the partially negatively charged functional groups on the polymer;
- removing liquid from said mixture to form a solid precursor material having the cations homogeneously distributed therein;
- and
- calcining said solid precursor material to form a mixed metal oxide powder.
Dependencies are inferred from the claim text.