Honeycomb filter

摘要

A honeycomb filter including partition walls having a porous partition wall base material and a surface layer provided on only inflow side or both inflow and outflow sides of the partition wall base material, and satisfying the following conditions capable of using as a DPF. The surface layer has a peak pore diameter of from 0.3 mum to 20 mum (exclusive) being equal to or smaller than the average pore diameter of the base material; the porosity of from 60% to 95% (exclusive) when measured by mercury porosimetry being larger than that of the base material; and the thickness L1 of from 0.5% to 30% (exclusive) of the partition wall thickness L2; and mass per filtration area of from 0.01 mg/cm2 to 6 mg/cm2 (exclusive). The base material has an average pore diameter of from 10 mum to 60 mum (exclusive) and a porosity of from 40% to 65% (exclusive).