Electrically conductive barium sulfate-containing composition and process of producing

US5997775A · kind A · utility

Assignee

• Mitsui Kinzoku Mitsui Maining & Smelting Co. Ltd. · JP

Inventors

• Takao Hayashi · Shimonoseki, JP
• Norihiro Sato · Shimonoseki, JP
• Manabu Hosoi · Saitama, JP
• Nobuyoshi Kasahara · Saitama, JP
• Clemens Aderhold · Krefeld, DE
• Wolf-Dieter Griebler · Moers, DE
• Jorg Hocken · Düsseldorf, DE
• Uwe Rosin · Sörup, DE
• Gunther Rudolph · Neuberg, DE

Key dates

• Filing date: Nov 21, 1997
• Grant date: Dec 7, 1999
• Expiry date: Nov 21, 2017

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/2991
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

The electrically conductive, barium sulfate-containing composition consists of BaSO.sub.4 particles having a surface area of from 0.1 to 150 m.sup.2 /g. The BaSO.sub.4 particles each are provided with a SnO.sub.2 coating having a thickness of 2 to 80 nm and containing from 1 to 15% by weight of the Sb.sub.2 O.sub.3. The electrically conductive, barium sulfate-containing composition is made by a method including the steps of adding a first acidic solution containing 1 to 95% by weight SnCl.sub.4 and a basic solution to an aqueous dispersion from 50 to 800 g/l of BaSO.sub.4 to make a basic mixture having a pH from 9 to 15; then adding an acid to the basic mixture to form an acidic mixture having a pH from 4 to 1; then adding a second acid solution containing 0.5 to 60% by weight of SbCl.sub.3 to the acidic mixture; separating the electrically conductive, barium sulfate-containing composition from the acidic mixture; and drying and igniting the separated electrically conductive, barium sulfate-containing composition at 300 to 800.degree. C.