# US 7,608,298 B2 · Method of manufacturing ceramic porous membrane > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,608,298 B2 - Document ID: US7608298B2 - Status: Granted - Kind: B2 - Application number: 11/858,973 - Filed: 2007-09-21 - Published: 2008-03-20 - Granted: 2009-10-27 - Earliest claimed: 2006-02-16 - Assignees: NGK Insulators, Ltd. - Inventors: Kei Tanaka - Web page: https://patentgrep.com/patent/US7608298B2 ## CPC - C04B 41/87: Ceramics - B01D 63/066: {with a porous block having membrane coated passages} - B01D 67/0048: {by sol-gel transition} - B01D 69/04: Tubular membranes - B01D 69/046: {characterised by the cross-sectional shape of the tube} - B01D 71/024: {Oxides} - B01D 71/027: {Silicium oxide} - C04B 35/46: based on titanium oxides or titanates (containing also zirconium or hafnium oxides, zirconates or hafnates C04B35/49) - C04B 35/624: Sol-gel processing - C04B 41/009: {characterised by the material treated} - C04B 41/4537: {by the sol-gel process} - B01D 2323/42: Details of membrane preparation apparatus - C04B 2111/00801: {Membranes; Diaphragms} - 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 - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) ## Abstract A method of manufacturing a ceramic porous membrane on inner wall surfaces of through holes of a porous base member. The through holes of the base member are arranged in a vertical direction, a ceramic sol liquid having a temperature difference of 50° C. or less between the sol liquid and the base member is supplied to the inner wall surface of the base member, the liquid supply is stopped when the sol liquid exceeds an upper end portion of the base member, and then the sol liquid is extracted from the bottom of the base member. After the sol liquid is completely extracted, a pressure difference is created so that a pressure on the side of an outer peripheral surface of the base member is lower than that on the side of the inner wall surface of the base member. ## Claims ### Claim 1 A method of manufacturing a ceramic porous membrane on one or more inner wall surfaces of a porous base member, the method comprising the steps of: providing a porous base member having a substantially cylindrical outer shape and having one or more through holes formed therein passing from a first end of the porous base member to an opposed second end of the porous base member in a longitudinal axis direction of the porous base member; orienting the porous base member in a vertical direction so that one of the first and second ends thereof defines a lower base surface and so that the longitudinal axis of the porous base member and the through holes thereof extend in the vertical direction; supplying, to inner wall surfaces of the one or more through holes of the porous base member, a ceramic sol liquid, wherein a temperature differential between the ceramic sol liquid and the porous base member is 50° C. or less; stopping the liquid supply at a stage when the ceramic sol liquid entirely covers the inner wall surfaces of the one or more through holes of the porous base member and discharging the ceramic sol liquid from the one of the first and second ends defining the base surface of the porous base member; and creating a pressure differential, only after the ceramic liquid sol is completely discharged from the porous base member, so that a pressure measured at an outer peripheral surface of the porous base member is lower than a pressure measured inside the one or more through holes of the porous base member. ### Claim 2 (depends on 1) The method of manufacturing the ceramic porous membrane according to claim 1, wherein the ceramic sol has an average particle diameter of 1 to 100 nm. ### Claim 3 (depends on 1) The method of manufacturing the ceramic porous membrane according to claim 1, wherein a membrane forming surface of the one or more through holes of the porous base member has an average pore diameter of 0.1 to 100 nm. ### Claim 4 (depends on 1) The method of manufacturing the ceramic porous membrane according claim 1, wherein the ceramic sol liquid is supplied to the inner wall surfaces of the porous base member from either one of the first and second ends of the porous base member. ### Claim 5 (depends on 1) The method of manufacturing the ceramic porous membrane according to claim 1, wherein a temperature of the ceramic sol liquid does not exceed 100° C. ### Claim 6 (depends on 1) The method of manufacturing the ceramic porous membrane according to claim 1, wherein the pressure differential is created by applying vacuum suction from the outer peripheral surface of the porous base member.