Patent attributes
A substrate with a surface-collection-layer includes a honeycomb substrate having a porous partition wall that defines and forms cells, and a plurality of plugging portions. A surface-collection-layer is formed on a surface of the partition wall that forms the remaining cells, and the thickness of the surface-collection-layer on the outlet-side open end is larger than the thickness of the surface-collection-layer in a center area of the substrate. The partition wall has predetermined thickness, porosity, and average pore size. The surface-collection-layer has a predetermined thickness, porosity, and average pore size, and the substrate has a predetermined cell density.