| abstract |
There is disclosed a fine particle collecting filter which enables effectively preventing damage due to a heat stress generated during recovery, without incurring increase of a pressure loss or deterioration of a PM collecting efficiency. A fine particle collecting filter 1 includes a honeycomb structure 2 in which a plurality of honeycomb segments 3 are integrally joined by a joining material 12, and has a constitution where an exhaust gas allowed to flow from an inlet end surface into cells 7 passes partition walls 8, and then flows out from an outlet end surface to the outsides of the cells 7. In the partition walls 8, SiC which is an aggregate is bound by Si which is a binding agent, at least one of an average open diameter of the pores which are open in a surface of each of the partition walls 8 that becomes an inlet side of the exhaust gas passing the partition wall 8 and an average open diameter of the pores which are open in a surface of the partition wall 8 that becomes an outlet side of the exhaust gas passing the partition wall 8 is from 0.1 to 5 µm, an average pore diameter of the whole partition wall 8 is from 10 to 30 µm, and a thermal conductivity of the partition walls 8 at room temperature is from 50 to 80 W/mK. |