Particulate alumina, method for producing particulate alumina, and composition containing particulate alumina
AssigneeShow A Denko K.K.
InventorsSusumu Shibusawa, Hidetoshi Okamoto, Hiroshi Takahashi, Nobuo Uotani, Koichiro Take
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Abstract
The present invention provides particulate alumina having a mean particle size corresponding to a volume-cumulative (50%) mean particle size (D50) of 1.5 to 4 μm and a ratio (D90/D1O) of D90 to D10 of 2.5 or less. The alumina contains secondary particles having a particle size of at least 10 μm in an amount of 0.1 mass % or less; secondary particles having a particle size of 0.5 μm or less in an amount of 5 mass % or less; and an α-phase as a predominant phase.fluoride. The present invention also provides a method for producing the particulate alumina.
Claims23
Particulate alumina having a mean particle size corresponding to a volume-cumulative (50%) mean particle size (D50) of 1.5 to 4 μm;
- having a ratio (D90/D10) of D90 to D10 of 2.5 or less;
- and containing secondary particles having a particle size of at least 10 μm in an amount of 0.1 mass % or less, secondary particles having a particle size of 0.5 μm or less in an amount of 5 mass % or less;
- and an α-phase as a predominant phase.
A method for producing particulate alumina comprising the steps of addinga halide other than a fluoride to aluminum hydroxidefluoride;
- firing the resultant mixture in a sealed container;
- and subsequently, crushing the fired product.
Particulate alumina which is produced by adding a halide other than fluoride to aluminum hydroxide;
- firing the resultant mixture in a sealed container;
- and subsequently, crushing the fired product.
Dependencies are inferred from the claim text.