Ceramic filter and process for making it
AssigneeToto Ltd.
InventorNobuyuki Maebashi
Life of this patent
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Abstract
A process for manufacturing a ceramic filter having a given pore size required as a filter membrane and also having superior alkali resistance and acid resistance. The filter of the present invention is produced by preparing an aggregate comprising alumina coarse particles and a sintering aid comprising alumina-zirconia mixed particles containing not more than 90 wt. % of alumina, blending said alumina coarse particles and alumina-zirconia mixed particles so as for alumina to be in an amount of from 80 to 99 wt. % based on the total weight of the starting materials, forming the blended starting materials to have a desired shape, and firing the formed product.
Claims15
A process for manufacturing a ceramic filter, comprising the steps of;
- preparing an aggregate comprising alumina coarse particles and a sintering aid comprising alumina-zirconia mixed fine particles containing not more than 90 wt. % of alumina;
- blending said alumina coarse particles and alumina-zirconia mixed fine particles so that alumina is in an amount of from 80 to 99 wt. % based on the total weight of the starting materials;
- forming the blended starting materials to have a desired shape;
- and
- sintering the formed product.
A sintered ceramic filter having a specified shape and comprising
- a base having an aggregate of coarse alumina particles and a mixture of fine particles of alumina and zirconia
- said fine particles containing 90 weight percent of alumina
- alumina constituting 80% to 90% of total weight of the coarse and fine particles, and
- a dense layer of porous material formed on a surface of said base.
A ceramic filter comprising
- a support of a mixture of sintered alumina coarse particles and alumina-zirconia particles,
- said alumina of said alumina-zirconia particles constituting no more than 90% by weight of the mixture,
- said alumina constituting between 80% to 99% by weight of the total weight of the mixture.
A ceramic filter comprising;
- a support obtained by sintering starting materials prepared by blending alumina coarse particles and a sintering aid comprising alumina-zirconia mixed fine particles containing not more than 90 wt. % of alumina, so that the alumina is in an amount of from 80 to 99 wt. % based on the total weight of the starting materials;
- and
- at least one dense layer formed on one surface of said support and having a pore size smaller than the pore size of said support.
Dependencies are inferred from the claim text.