Hideyuki Okinaka

A plasticizer removal method in electroceramic green bodies using supercritical carbon dioxide

A novel selective removal method for plasticizer in green bodies of electroceramic components using supercritical carbon dioxide has been proposed and successfully demonstrated. The effects of temperature, pressure, and carbon dioxide flow rate on the weight decrease factor were investigated. The plasticizer was effectively removed by treatment with supercritical carbon dioxide at 10 MPa in the low-temperature region below 50°C and in the high-temperature region above 150°C. The extract collected in the collector cylinder after experimentation at 40°C and 10 MPa was confirmed by infrared spectroscopy to be plasticizer originating in the green bodies. The key parameters governing the plasticizer removal rate were identified as the carbon dioxide density in the low-temperature region and the vapor pressure of the plasticizer in the high-temperature region. The proposed method is as yet imperfect, since some defects were frequently detected on the surface of the green bodies after completion of the experiments. However, the proposed removal method is likely to have significant industrial potential, since it would enable a fabrication process that is both efficient and environmentally friendly.