CONDUCTIVE BARIUM SULFATE FILLER AND ITS PRODUCTION

摘要

PURPOSE:To obtain a filler which can be colored with any desired color tone by adding a colorant because of its whiteness or transparency and has high dispensability in plastics. CONSTITUTION:The filler consists of a particulate core material comprising barium sulfate and a coating film comprising tin dioxide and covering the surface of the core material. The core material has a specific surface area of 0.1-150m<2>/g in an uncoated state, and the film has a thickness of 2-80nm. This filler is produced by mixing a suspension containing barium sulfate particles of a specific surface area of 0.1-150m<2>/g in a concentration of 10-1000g/l with an alkaline solution containing a tetravalent tin compound in a concentration of 1-95wt.% to form a mixture of a pH of 11-14, adding an acid to this mixture to adjust the pH to 1-5, subjecting the mixture to solid/ liquid separation, drying the precipitate, and firing it in an inert atmosphere or a reducing atmosphere.