Patent ID: 6312627
Filing Date: 2001-11-06
Classification: C04B

Abstract:
A method for preparing a ceramic composition comprising:(a) forming an aqueous ceramic slurry comprising from 45 to 85 weight percent mineral matrix material selected from one or more of stoneware clay, tile clay, natural ball clay, ball clay, feldspar, silica, flint and ferrites, based on weight of the aqueous ceramic slurry, and from 0.05 to 10 weight percent polymeric additive, based on weight of the mineral matrix material;(b) dewatering the aqueous ceramic slurry to form a mineral matrix material-polymer additive composite by a process selected from one or more of spray drying, slip casting and filter pressing;(c) compacting the mineral matrix material-polymer additive composite to form a green body; and(d) sintering the green body;wherein the polymer additive is selected from one or more polymers comprising as polymerized units from 0.1 to 20 weight percent, based on weight of the polymer, of acid-containing monomer selected from one or more of acrylic acid, methacrylic acid and the alkali metal and ammonium salts thereof; and wherein the aqueous ceramic slurry retains a viscosity of at least 0.15 to less than 1.5 pascal.multidot.seconds, for at least 24 hours after the polymer additive has been added to the aqueous ceramic slurry.