PRODUCTION OF SILICON NITRIDE POROUS HEAT RESISTANT MATERIAL AND DIESEL ENGINE EXHAUST GAS FILTER MADE BY USING SAME

摘要

PURPOSE:To provide a method for producing a silicon nitride porous heat resistant material affording an exhaust gas purifying filter which has very large porosity and is lightweight and has low pressure loss and excels in mechanical strength and excels in heat and impact resistance and filter efficiency when used as a parent material for a filter or the like. CONSTITUTION:This method comprises the steps of dispersing and mixing silicon nitride powder, organic fiber and a sintering assistant in water; adding a coagulant to the dispersed and mixed system to coagulate it; manufacturing the coagulated material to sheets by a sheet manufacturing method; working the manufactured sheets into a honeycomb; working the honeycomb-shaped worked material into a laminate or a roll; subjecting the manufactured sheets or worked material worked in the working process to binder removal; and making the heat treatment of the worked material subjected to binder removing in an atmosphere of nitrogen.