| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an improved material and method capable of simultaneously preserving low thermal expansion coefficient and high gas permeability of a ceramic support or filter material even though the amount of a wash-coating to be added is made large. <P>SOLUTION: A method for forming a porous ceramic filter with a catalyst coating comprises the steps of: applying a polymer solution or dispersion, which comprises a thermally cross-linkable, thermally decomposable and water-soluble hydrocarbon polymer selected from the group comprising liquid vehicle, cross-linking promoter and amine-functional ionene, polyvinyl alcohol, polyacrylic acid and polyacrylic amine, to a porous ceramic catalyst filter; heating the resulting ceramic filter to cross-link the hydrocarbon polymer and provide a porous ceramic filter, the micro pore portion and micro channel portion of which are plugged preferentially with the cross-linked polymer; applying an aqueous wash-coating film or a catalyst coating film to the coated filter to remove the filter covered with film by pyrolytically decomposing to obtain such the porous ceramic filter that the catalyst coating or a wash-coating is selectively distributed in a coarse pore portion thereof. <P>COPYRIGHT: (C)2013,JPO&INPIT |
