Acid resistant ceramic materials, filter using the same, and preparation of them

Abstract

Abstract The present invention provides porous ceramic materials having good resistance to heat, acid and base, comprising three or more oxides selected from an oxide of silicon (SiO ), an oxide of aluminum (Al O ), an oxide of a transition metal, MxOy, [wherein M represents a 4B, 5B or 6B-group transition metal which can be selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W or Ce, x represents an integer of 1 to 3, and y represents an integer of 1 to 3] and its preparation. By applying ceramic materials prepared according to the present invention that are structurally, thermally and chemically stable to a porous honeycomb support for the purification of exhaust gas or to a filter (DPF, Diesel Particulate Filter) for the purification of diesel engine exhaust gas, it is possible to prevent or remarkably reduce any structural destruction caused by corrosive gas, which results from employing a cordierite material as a structural support.

Description

technical field

[0001] The present invention relates to a ceramic material having excellent heat resistance, acid resistance and alkali resistance, a filter using the ceramic material, and a method for preparing them.

[0002] As catalyst supports or filter systems for operation at high temperatures (e.g. supports for catalysts for purifying automobile exhaust gases, heat exchangers for gas turbines, filter systems for purifying diesel automobile exhaust gases (DPF, diesel particulate filter) or similar), mullite (which has 2SiO 2 -3Al 2 o 3 composition) and cordierite (which has 2MgO-2Al 2 o 3 -5SiO 2 Composition) because of its superior thermal properties (such as low thermal expansion coefficient (1 ~ 5x10 -6 / K), thermal conductivity, dielectric constant or similar) and their chemical stability characteristics are widely used.

[0003] However, there are some problems: mullite is rarely found in nature, so it is only obtained through synthetic routes; and, because o...