Method for improving the thermal shock resistance of a washcoated body
AssigneeCorning Incorporated
InventorsPatricia A. Beauseigneur, Irwin M. Lachman, Mallanagouda D. Patil
Life of this patent
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Abstract
A method for producing a thermally shock resistant washcoated substrate involves introducing a buffer solution into the microcracks, and optionally the micropores of a porous sintered body, the pH of the buffer solution being at a predetermined value to result in the formation of a gel on contact of the buffer solution with the slurry which is to be subsequently applied, contacting the body with a washcoating slurry to form a gel at the interface of the buffer solution and slurry. Formation of the gel prevents the slurry from entering the microcracks. The body is then calcined at a temperature and for a time sufficient to form the washcoated substrate.
Claims17
A method for producing a thermally shock resistant washcoated substrate, said method comprising:
- a) providing a porous sintered body having microcracks and pores;
- b) providing a washcoating slurry which comprises an oxide having a surface area of no less than about 50 m.sup.2 /g or a precursor of said oxide and a gel-forming agent, and providing a buffer solution, wherein the washcoating slurry and the buffer solution are at pH's which result in formation of a gel on contact of the slurry with the buffer solution;
- c) introducing the buffer solution into the microcracks, and optionally into the pores of the porous sintered body which have a size of less than about 5 micrometers in diameter,
- d) contacting the porous sintered body having the introduced buffer solution with the washcoating slurry to form a gel at the interface of said buffer solution and said washcoating slurry, whereby the slurry is prevented from entering the microcracks;
- and
- e) calcining the porous sintered body from step d at a temperature and for a time sufficient to form said washcoated substrate.
Dependencies are inferred from the claim text.