Metal oxide powder and method for manufacture thereof
AssigneeTokuyama Corporation
InventorsWakana Tomimatsu Fujimoto, Tadahiro Fukuju, Hiroshi Numa
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Abstract
The present invention provides a globular-shaped metal oxide powder with excellent thermal insulation performance and reduced bulk density, and a method of manufacture thereof, wherein the metal oxide powder has globular independent particles as the main component, and has BET specific surface area of 400 to 1000 m2/g, BJH pore volume of 2 to 8 mL/g, and oil absorption of no less than 250 mL/100g. The present invention also provides a method for manufacturing the hollow and globular shaped metal oxide powder including the step of forming an O/W/O emulsion.
Claims9
A metal oxide powder comprising globular independent particles as main component,
- said metal oxide powder having:
- BET specific surface area of 400 to 1000 m2/g;
- BJH pore volume of 2 to 8 mL/g;
- and
- oil absorption of no less than 250 mL/100 g,
- wherein each said independent particle includes therein one or more hollow space having a size of 0.5 to 15 μm.
(canceled)
A method for manufacturing a hollow and globular shaped metal oxide powder comprising the successive steps of:
- (i) preparing an aqueous metal oxide sol;
- (ii) forming an O/W/O emulsion wherein the aqueous metal oxide sol composes the W phase of the O/W/O emulsion;
- (iii) causing gelation of the aqueous metal oxide sol, thereby converting the O/W/O emulsion into a dispersion of a gel;
- (iv) replacing water in the dispersion with a solvent which has a surface tension at 20° C. of no more than 30 mN/m;
- (v) treating the gel with a hydrophobing agent;
- and
- (vi) removing the solvent used in the replacing step (iv).
Dependencies are inferred from the claim text.