US Patent No. 9,273,574

EXHAUST GAS PURIFYING FILTER


Patent No. 9,273,574
Issue Date March 01, 2016
Title Exhaust Gas Purifying Filter
Inventorship Masamichi Tanaka, Tokyo (JP)
Atsushi Kishimoto, Tokyo (JP)
Tadashi Neya, Tokyo (JP)
Keita Ishizaki, Utsunomiya (JP)
Assignee SUMITOMO OSAKA CEMENT CO., LTD., Tokyo (JP) HONDA MOTOR CO., LTD., Tokyo ...

Claim of US Patent No. 9,273,574

1. An exhaust gas purifying filter comprising
an inflow section into which exhaust gas including particulate matter flows,
an exhaust section in which purified gas exits the exhaust gas purifying filter, and
a filter substrate which is constructed of a porous body,
wherein the filter substrate includes porous partitions and gas passages which are enclosed by the partitions,
a porous film, which includes silicon carbide particles and pores having a smaller pore diameter than the pores of the partitions,
is provided on the surface of the partitions, the pores existing in an outer surface portion and an inner portion of the porous
film,

a silicon dioxide layer is formed on a surface of silicon carbide particles which configure the outer surface portion of the
porous film,

the gas passage is constructed of a structure in which an upstream side end and a downstream side end are alternately occluded
when viewed from a flow direction of the exhaust gas, a cell in which the upstream side end is opened is an inflow cell, and
the porous film is formed on an inner wall surface of the porous partition constructing the inflow cell,

a thickness of the silicon dioxide layer is 0.5 nm or more and 30 nm or less, and wherein the porous film is obtained by oxidizing
a sintered body of the silicon carbide particles.