Cordierite substrates
AssigneeCorning Incorporated
InventorHoward J. Locker
Life of this patent
Estimating the term…
Abstract
Cordierite-forming green substrates having high wet strength are prepared from fine-particle size minerals, including about 5 to 30 weight percent of delaminated kaolin and, preferably, about 15 to 39 weight percent calcined kaolin. The other fine-particle size minerals utilized are preferably talc having a particle diameter of about seven microns or less and alumina having a particle diameter of about one micron or less.
Claims45
A plasticizable admixture for use in preparing a substrate having cordierite as its primary phase, said admixture comprising the minerals
- (a) at least one source of alumina having an average particle diameter of about one micron or less;
- (b) at least one source of magnesia having an average particle diameter of about seven microns or less;
- (c) at least one kaolin having an average particle diameter, measured by x-ray sedigraph, not greater than about two microns, at least a portion of said kaolin being a delaminated kaolin, said delaminated kaolin comprising between about five and about thirty weight percent based on total minerals in the admixture, and at least a portion of said kaolin being a calcined kaolin, said calcined kaolin comprising about 15 to about 39 weight percent based on total minerals in the admixture,
- said mixture having a chemical composition comprising, by weight on an analytical oxide basis, about 11.5-16.5% MgO, about 33-41% Al.sub.2 O.sub.3, and about 46.6-53.0% SiO.sub.2.
An extrudable mixture for use in preparing a substrate having cordierite as its primary phase, said admixture comprising the minerals:
- (a) at least one source of alumina having an average particle diameter of about one micron or less;
- (b) at least one source of magnesia having an average particle diameter of about seven microns or less;
- (c) at least one kaolin having an average particle diameter, measured by x-ray sedigraph, not greater than about two microns, at least a portion of said kaolin being a delaminated kaolin, said delaminated kaolin comprising between about five and about thirty weight percent based on total minerals in the admixture, and at least a portion of said kaolin being a calcined kaolin, said calcined kaolin comprising about 15 to about 39 weight percent based on total minerals in the admixture,
- and further comprising water in an amount between about 28 and 35 weight %, based on total organic and inorganic solids;
- said admixture having a chemical composition comprising, by weight on an analytical oxide basis, about 11.5-16.5% MgO, about 33-41% Al.sub.2 O.sub.3, and about 46.6-53.0% SiO.sub.2.
A method of producing a green substrate which, upon sintering, will yield a ceramic substrate having cordierite as its primary phase comprising:
- (A) preparing a plasticizable admixture having a chemical comprising, by weight on an analytical oxide basis, about 11.5-16.5% MgO, about 33-41% Al.sub.2 O.sub.3, and about 46.6-53.0% SiO.sub.2, said plasticizable admixture comprising the minerals:
- (a) at least one source of alumina having an average particle diameter of about one micron or less;
- (b) at least one source of magnesia having an average particle diameter of about seven microns or less;
- (c) at least one kaolin having an average particle diameter, measured by x-ray sedigraph, not greater than about two microns, at least a portion of said kaolin being a delaminated kaolin, said delaminated kaolin comprising between about five and about thirty weight percent based on total minerals in the admixture, and at least a portion of said kaolin being a calcined kaolin, said calcined kaolin comprising about 15 to about 39 weight percent based on total minerals in the admixture;
- (B) adding water and extrusion aids to said plasticizable admixture and kneading said admixture to create an extrudable admixture;
- (C) extruding said plasticizable admixture to form said green substrate.
A method of producing a green substrate which, upon sintering, will yield a ceramic substrate having cordierite as its primary phase comprising:
- (A) preparing a plasticizable admixture having a chemical comprising, by weight on an analytical oxide basis, about 11.5-16.5% MgO, about 33-41% Al.sub.2 O.sub.3, and about 46.6-53.0% SiO.sub.2, said plasticizable admixture comprising the minerals:
- (a) at least one source of alumina having an average particle diameter of about one micron or less;
- (b) at least one source of magnesia having an average particle diameter of about seven microns or less;
- (c) at least one kaolin having an average particle diameter, measured by x-ray sedigraph, not greater than about two microns, at least a portion of said kaolin being a delaminated kaolin, said delaminated kaolin comprising between about five and about thirty weight percent based on total minerals in the admixture, and at least a portion of said kaolin being a calcined kaolin, said calcined kaolin comprising about 15 to about 39 weight percent based on total minerals in the admixture;
- (B) extruding said plasticizable admixture to form said green substrate.
Dependencies are inferred from the claim text.