# US 2016/0250577 A1 · Cordierite-type ceramic honeycomb structure and its production method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2016/0250577 A1 - Document ID: US20160250577A1 - Status: Published application - Kind: A1 - Application number: 14/896,808 - Filed: 2014-09-24 - Published: 2016-09-01 - Earliest claimed: 2013-09-24 - Assignees: Hitachi Metals, Ltd. - Applicants: Hitachi Metals, Ltd. - Inventors: Shunji OKAZAKI - Web page: https://patentgrep.com/patent/US20160250577A1 ## CPC - F01N 3/2828: {Ceramic multi-channel monoliths, e.g. honeycombs} - B01D 46/2429: {of the honeycomb walls or cells} - B01D 46/24491: {Porosity} - B01D 46/24492: {Pore diameter} - B01D 46/247: {of the cells} - B01D 46/2484: {Cell density, area or aspect ratio} - B01D 53/9418: {for removing nitrogen oxides by selective catalytic reduction [SCR] using a reducing agent in a lean exhaust gas} - B01J 23/42: Platinum - B01J 29/70: of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65 - B01J 35/57: Honeycombs - B01J 37/0018: {Addition of a binding agent or of material, later completely removed among others as result of heat treatment, leaching or washing,(e.g. forming of pores; protective layer, desintegrating by heat)} - B01J 37/08: Heat treatment {(B01J37/0009, B01J37/0018 take precedence)} - B28B 3/20: wherein the material is extruded {(extrusion moulding of plastics B29C48/00)} - C04B 16/082: {other than polystyrene based, e.g. polyurethane foam} - C04B 35/195: Alkaline earth aluminosilicates, e.g. cordierite {or anorthite} - C04B 35/66: Monolithic refractories or refractory mortars, including those whether or not containing clay {(making or repairing of linings F27D1/16)} - C04B 38/0006: {Honeycomb structures (from one or more corrugated sheets by winding or stacking C04B38/0083)} - C04B 38/06: by burning-out added substances {by burning natural expanding materials or by sublimating or melting out added substances} - B01D 46/2498: {The honeycomb filter being defined by mathematical relationships} - B01D 2251/208: Hydrocarbons - B01D 2255/1021: Platinum - B01D 2255/915: Catalyst supported on particulate filters - B01D 2255/9202: Linear dimensions - B01D 2255/9205: Porosity - B01D 2258/012: Diesel engines and lean burn gasoline engines - B28B 2003/203: {for multi-channelled structures, e.g. honeycomb structures} - C04B 2111/0081: {as catalysts or catalyst carriers} - F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16) - 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) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - B28B: SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER (foundry moulding B22C; working stone or stone-like material B28D; shaping of substances in a plastic state, in general B29C; making layered products not composed wholly of these substances B32B) - 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 ## Abstract A cordierite-type ceramic honeycomb structure having large numbers of flow paths partitioned by porous cell walls; the cell walls having (a) porosity of more than 65% and 75% or less, (b) in a pore diameter distribution measured by mercury porosimetry, (i) a pore diameter d10 at a cumulative pore volume corresponding to 10% of the total pore volume being less than 50 μm, a pore diameter (median pore diameter) d50 at 50% being 18-27 μm, a pore diameter d90 at 90% being 10 μm or more, and (d10−d90)/d50 being 2.3 or less; (ii) σ[=log(d20)−log(d80)] being 0.25 or less, wherein σ represents the difference between a logarithm of a pore diameter d20 at a cumulative pore volume corresponding to 20% of the total pore volume and a logarithm of a pore diameter d80 at a cumulative pore volume corresponding to 80% of the total pore volume; and (iii) the maximum of the inclination Sn=−(Vn−Vn-1)/[log(dn)−log(dn-1)] of a curve of a cumulative pore volume to a pore diameter being 3 or more, wherein dn and Vn are respectively a pore diameter and a cumulative pore volume at an n-th measurement point, and dn-1 and Vn-1 are respectively a pore diameter and a cumulative pore volume at a (n−1)-th measurement point. ## Claims ### Claim 1 A cordierite-type ceramic honeycomb structure having large numbers of flow paths partitioned by porous cell walls, (a) said cell walls having porosity of more than 65% and 75% or less; and (b) in a pore diameter distribution measured by mercury porosimetry, (i) a pore diameter d10 at a cumulative pore volume (cumulative volume of pores in a range from the maximum pore diameter to a particular pore diameter) corresponding to 10% of the total pore volume being less than 50 μm, a pore diameter (median pore diameter) d50 at 50% being 18 μm or more and 27 μm or less, a pore diameter d90 at 90% being 10 μm or more, and (d10−d90)/d50 being 2.3 or less; (ii) σ[=log(d20)−log(d80)] being 0.25 or less, wherein σ represents the difference between a logarithm of a pore diameter d20 at a cumulative pore volume corresponding to 20% of the total pore volume and a logarithm of a pore diameter d80 at a cumulative pore volume corresponding to 80% of the total pore volume; and (iii) the maximum of the inclination Sn=−(Vn−Vn-1)/[log(dn)−log(dn-1)] of a curve of a cumulative pore volume to a pore diameter being 3 or more, wherein dn and Vn are respectively a pore diameter and a cumulative pore volume at an n-th measurement point, and dn-1 and Vn-1 are respectively a pore diameter and a cumulative pore volume at a (n−1)-th measurement point. ### Claim 2 (depends on 1) The cordierite-type ceramic honeycomb structure according to claim 1, wherein pores open on the cell wall surfaces have (i) an opening area ratio of 25-50%, and (ii) an area-based median opening diameter D50 (expressed by equivalent circle diameter) of 25-50 μm. ### Claim 3 (depends on 1) The cordierite-type ceramic honeycomb structure according to claim 1, wherein the maximum of said Sn is 3.5 or more. ### Claim 4 (depends on 1) The cordierite-type ceramic honeycomb structure according to claim 1, wherein the maximum of said Sn is 4.0 or more. ### Claim 5 A method for producing a cordierite-type ceramic honeycomb structure comprising the steps of extruding a moldable material comprising a ceramic material and a pore-forming material constituted by hollow resin particles coated with inorganic powder to form a predetermined green body, and drying and sintering said green body; said moldable material comprising 8-16% by mass of said pore-forming material per 100% by mass of said ceramic material; said pore-forming material having a median diameter D50 of 25-35 μm, a particle diameter D10 (at a cumulative volume corresponding to 10% of the total volume) of 14-24 μm, and a particle diameter D90 (at a cumulative volume corresponding to 90% of the total volume) of 45-60 μm, in a curve expressing the relation of a particle diameter to a cumulative volume (cumulative volume of particles having diameters equal to or smaller than a particular particle diameter), a particle diameter distribution deviation SD [=log(D80)−log(D20)] being 0.4 or less, wherein D20 is a particle diameter at a cumulative volume corresponding to 20% of the total volume, and D80 is a particle diameter at a cumulative volume corresponding to 80% of the total volume, D20