| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a purification filter having an improved collection efficiency and suppressed decrease of pressure loss, a production method therefor, and an exhaust gas purification apparatus. <P>SOLUTION: The purification filter comprises a whisker formed on a raw material substrate made of an alloy or a ceramic containing Mn, Al, Cr, In, Ag, Ga, Sn, Cu, Sc, Ge, Ti, Si, and the like. The raw material substrate is a porous material having an average fine pore diameter larger than the average diameter of the whisker. The raw material substrate is composed by filling a carrier with a powdery granule. The purification filter is produced by adjusting the contents of the elements contained in the raw material substrate and controlling the thickness and length of the whisker to be formed by heating in an inert gas atmosphere in the presence of a slight amount of oxygen. The exhaust gas purification apparatus comprises two or more layers of purification filters; a purification filter comprising a whisker formed on a raw material substrate and having a longer average length and a thicker thickness on the upstream side and a purification filter comprising a whisker formed on a raw material substrate and having a shorter average length and a thinner thickness on the downstream side. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
