# US 5,348,760 A · Surface treated ceramic powders > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,348,760 A - Document ID: US5348760A - Status: Granted - Kind: A - Application number: 08/134,777 - Filed: 1993-10-12 - Granted: 1994-09-20 - Earliest claimed: 1993-10-12 - Assignees: Aluminum Company of America - Inventors: Anthony A. Parker; Edward M. Anderson; Todd T. Stanzione - Web page: https://patentgrep.com/patent/US5348760A ## CPC - C04B 35/63448: {obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds} - B01J 2/30: using agents to prevent the granules sticking together; Rendering particulate materials free flowing in general, e.g. making them hydrophobic - C04B 35/62655: {Drying, e.g. freeze-drying, spray-drying, microwave or supercritical drying} - C04B 35/628: Coating the powders {or the macroscopic reinforcing agents} - C04B 2235/3217: Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina - C04B 2235/3222: Aluminates other than alumino-silicates, e.g. spinel (MgAl2O4) - C04B 2235/3232: Titanium oxides or titanates, e.g. rutile or anatase - C04B 2235/3236: Alkaline earth titanates - C04B 2235/3241: Chromium oxides, chromates, or oxide-forming salts thereof - C04B 2235/3244: Zirconium oxides, zirconates, hafnium oxides, hafnates, or oxide-forming salts thereof - C04B 2235/3248: Zirconates or hafnates, e.g. zircon - C04B 2235/3445: Magnesium silicates, e.g. forsterite - C04B 2235/3463: Alumino-silicates other than clay, e.g. mullite - C04B 2235/3481: Alkaline earth metal alumino-silicates other than clay, e.g. cordierite, beryl, micas such as margarite, plagioclase feldspars such as anorthite, zeolites such as chabazite - C04B 2235/5436: micrometer sized, i.e. from 1 to 100 micron - C04B 2235/608: Green bodies or pre-forms with well-defined density - C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS ## Abstract A method of reducing the agglomeration of ceramic powder materials, the method comprising: (a) providing a ceramic powder comprising ceramic particles; (b) coating the ceramic particles with a solution containing from 0.05-0.5 wt. % of a polysiloxanol oligomer of a trialkoxysiloxane monomer having the structure Si(OR').sub.3 wherein R' represents a lower C.sub.1 -C.sub.4 alkoxy group selected from the group consisting of methoxy, ethoxy, isopropoxy and n-butoxy and wherein the oligomer has chains having a number average distribution with a number average degree of polymerization X.sub.n in the range above 2 but below that near the gel point; and (c) drying the ceramic powder. ## Claims ### Claim 1 A method of reducing the agglomeration of ceramic powder materials, the method comprising: (a) providing a ceramic powder comprising ceramic particles; (b) coating said ceramic particles with an oligomer of a trialkoxysiloxane having the structure Si(OR').sub.3 wherein R' represents a lower C.sub.1 -C.sub.4 alkoxy group selected from the group consisting of methoxy, ethoxy, isopropoxy and n-butoxy; and, wherein said oligomer has chains having a number average distribution with a number average degree of polymerization X.sub.n in the range above 2 but below the gel point; and (c) drying said ceramic powder. ### Claim 2 (depends on 1) The method of claim 1 in which said chains have a number average distribution with a number average degree of polymerization X.sub.n in the range from about 3 to 10. ### Claim 3 (depends on 1) The method of claim 1 in which said oligomer is pre-hydrolyzed n-octyltriethoxysilane. ### Claim 4 (depends on 1) The method of claim 1 in which said oligomer is present in an amount in the range from about 0.005 to about 5 wt. % of said ceramic powder. ### Claim 5 (depends on 1) The method of claim 1 in which said oligomer is present in an amount in the range from about 0.05 to about 2 wt. % of said ceramic powder. ### Claim 6 (depends on 1) The method of claim 1 in which ceramic particles are selected from the group consisting of alumina, chromia, aluminum silicate, cordierite, mullite, spinel, forsterite, barium titanate, magnesium silicate, steatite, titanium dioxide, zircon, zirconium dioxide, and combinations thereof. ### Claim 7 (depends on 1) The method of claim 1 in which said drying is performed at a temperature between about 40.degree. C. and 200.degree. C. ### Claim 8 (depends on 1) The method of claim 1 in which said drying is performed with agitation at a temperature greater than ambient temperature. ### Claim 9 (depends on 1) The method of claim 1 in which said drying is performed at a temperature greater than about 100.degree. C. ### Claim 10 (depends on 1) The method of claim 1 in which said coating of ceramic particles is performed by: adding said oligomer to said ceramic particles and dry mixing. ### Claim 11 (depends on 1) The method of claim 1 in which said coating of ceramic particles is performed by: determining the amount needed to provide a monolayer coverage of the ceramic particles; and adding said oligomer to said ceramic particles and dry mixing. ### Claim 12 (depends on 1) The method of claim 1 in which (a) includes providing a ceramic powder having at least 50% of its particles less than about 10 .mu.m. ### Claim 13 (depends on 1) The method of claim 1 which further includes: (d) incorporating said dried ceramic particles to a ceramic slurry. ### Claim 14 (depends on 1) The method of claim 1 which further includes: (d) incorporating said dried ceramic particles to a ceramic slurry formed from a solvent selected from the group consisting of water, ethanol, toluene and methanol. ### Claim 15 (depends on 1) The method of claim 1 which further includes: (d) incorporating said dried ceramic particles to a ceramic slurry; and (e) forming said slurry into a green ceramic body. ### Claim 16 (depends on 1) The method of claim 1 which further includes: (d) incorporating said dried ceramic particles to a ceramic slurry; and (e) forming said slurry into a green ceramic body by a method selected from the group comprising extrusion, pressing, wet pressing, jiggering, ram pressing, injection molding, casting and doctor blading. ### Claim 17 A method of reducing the agglomeration of ceramic powder materials, the method comprising: (a) providing a ceramic powder comprising ceramic particles; (b) coating said ceramic particles with a polysiloxanol oligomer of a trialkoxysiloxane monomer having the structure Si(OR').sub.3 wherein R' represents a lower C.sub.1 -C.sub.4 alkoxy group selected from the group consisting of methoxy, ethoxy, isopropoxy and n-butoxy; and, wherein said oligomer has chains having a number average distribution with a number average degree of polymerization X.sub.n in the range above 2 but below the gel point; (c) drying said ceramic powder; and (d) incorporating said dried ceramic powder to a ceramic slurry. ### Claim 18 (depends on 17) The method of claim 17 which further includes: (e) forming said slurry into a green ceramic body.