Chemistry of inorganic compounds – Oxygen or compound thereof – Metal containing
Reexamination Certificate
2006-08-01
2010-12-21
Silverman, Stanley (Department: 1793)
Chemistry of inorganic compounds
Oxygen or compound thereof
Metal containing
C423S594160
Reexamination Certificate
active
07854916
ABSTRACT:
The present invention relates to a hydrothermal synthesis for preparing barium titanate powder as the essential material for a multi-layer ceramic capacitor. The object of the invention is to prepare barium titanate powder having high purity, particle size of submicron order, uniform particle distribution and excellent crystallinity, by reacting hydrous titanic acid compound prepared via sulfuric acid process with crystalline titanium oxide and barium hydroxide, as the starting material, at a temperature between 60° C. and 300° C. under a pressure between 5 Kgf/cm2 and 50 Kgf/cm2. The process for preparing barium titanate according to the present invention provides barium titanate powder having Ba/Ti molar ratio of 1.000±0.002 and high purity by applying calcination under reductive condition to the solid product obtained from hydrous titanic acid compound prepared via sulfuric acid process with crystalline titanium oxide and barium hydroxide, as the starting substances, to convert barium sulfate, which was produced from residual sulfide in the raw material, to barium titanate.
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Baik Jin-Soo
Jang Young-Soo
Lim Seong-Jae
Paik Choong-Hoon
Park Sei-Ung
Clark & Brody
Hanwha Chemical Corporation
Silverman Stanley
Zimmer Anthony J
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