| 摘要 |
<p>1462237 Spongy ceramic structures HOECHST AG 28 Oct 1974 [7 Nov 1973] 46457/74 Heading C1J Spongy ceramic structures useful as supports for catalysts in the decontamination of motor exhaust gas are prepared by aggregating expanded polystyrene spheroids in a cylinder closable at one of its ends by pouring the spheroids thereinto; deforming the polystyrene spheroids by plasticizing their surface areas so as to effect bonding of the spheroids via contact areas to form a spheroskeleton leaving hollow spaces between the individual spheroids; forcing an aqueous suspension of ceramic material through the spheroskeleton in the cylinder so as to fill the hollow spaces left between the spheroids forming the spheroskeleton with the suspension; drying the suspension at temperatures of 20 to 95‹ C.; taking the spheroskeleton with the ceramic material therein from the cylinder; removing the polystyrene spheroskeleton with the resultant formation of a skeleton consisting substantially of the ceramic material forced into the initially hollow spaces in the spheroskeleton; and calcining the skeleton at temperatures of 1000 to 1500‹ C. The spheroids may be plasticized by treatment with an organic solvent or by heating. The flowability of the suspension may be improved by adding a non-ionic dispersant thereto. Suitable ceramic materials are fine particulate, highly reactive aluminium oxide and a mixture ofα-Al(OH) 3 and bentonite. The spheroskeleton may be removed by fusion, depolymerisation, oxidation or by extraction with an organic solvent.</p> |
