US4869944A
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US
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Cordierite honeycomb-structural body and a method for producing the same
Assignee: NGK Insulators Ltd
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Filing: 1988-02-03
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Granted: 1989-09-26
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Expires: 2008-02-03
Abstract
Abstract A cordierite honeycomb structural body to be used as a catalyst carrier, having excellent heat resistance, thermal shock resistance and coatability with a high specific surface area material and a catalyst is disclosed, which have a chemical composition consisting mainly of 42-56% by weight SiO 2 , 30-45% by weight of Al 2 O 3 and 12-16% by weight of MgO, having a crystal phase consisting mainly of cordierite, and having coefficients of thermal expansion of not higher than 0.3×10 -6 /°C. in the flow-passage direction of the honeycomb structure and not higher than 0.5×10 -6 /°C. in a direction perpendicular to the flow-passage of the honeycomb structure within the temperature range of 40°-800° C. A cordierite honeycomb-structural body, wherein a distribution of diameters of pores, relative to a total volume of pores having a diameter of 0.5-5 μm is not less than 40% and the total volume of pores having a diameter of not smaller than 10 μm is not more than 30% based on the total pore volume in the body. The body has excellent coatability and thermal shock resistance after coating.
Inventors
- 👤 Takashi Harada
- 👤 Toshiyuki Hamanaka
- 👤 Kunikazu Hamaguchi
- 👤 Seiichi Asami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:28
CPC Classifications
C; C04; C04B; C04B38/00; C04B38/0006; B; B01; B01J; B01J21/00; B01J21/14; C04B35/00; C04B35/01; C04B35/16; C04B35/18; C04B35/195; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24149; Y10T428/24744
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
116 words
A cordierite honeycomb-structural body to be used as a catalyst carrier, comprising: a composition consisting mainly of 42-56% by weight of SiO 2 , 30-45% by weight of Al 2 O 3 and 12-16% by weight of MgO; a crystal phase consisting mainly of cordierite; a porosity of greater than 30% and not greater than 42%; a coefficient of thermal expansion of not greater than 0.3×10 -6 /°C. within a temperature range of 40°-800° C. in a flow-passage direction of the honeycomb structural body; and a coefficient of thermal expansion of not greater than 0.5×10 -6 /°C. within a temperature range of 40°-800° C. in a direction perpendicular to the flow-passage of the honeycomb structural body.
Claim 2
Dependent Claim
116 words
A cordierite honeycomb-structural body to be used as a catalyst carrier, comprising: a composition consisting mainly of 42-56% by weight of SiO 2 , 30-45% by weight of Al 2 O 3 and 12-16% by weight of MgO; a crystal phase consisting mainly of cordierite; a porosity of greater than 30% and not greater than 42%; a coefficient of thermal expansion of not greater than 0.3×10 -6 /°C. within a temperature range of 40°-800° C. in a flow-passage direction of the honeycomb structural body; and a coefficient of thermal expansion of not greater than 0.5×10 -6 /°C. within a temperature range of 40°-800° C. in a direction perpendicular to the flow-passage of the honeycomb structural body.
Claim 3
Dependent Claim
37 words
A cordierite honeycomb-structural body according to claim 1, wherein the coefficient of thermal expansion within the temperature range of 40°-800° C. in the flow-passage direction of the honeycomb structural body is not greater than 0.2×10 -6 /°C.
Claim 4
Dependent Claim
63 words
A cordierite honeycomb-structural body according to claim 1, wherein a total volume of pores having a diameter of 0.5-5 μm is not less than 40% based on the total pore volume of the body and a total volume of pores having a diameter of not smaller than 10 μm is not greater than 30% based on the total pore volume of the body.
Claim 5
Dependent Claim
63 words
A cordierite honeycomb-structural body according to claim 1, wherein a total volume of pores having a diameter of 0.5-5 μm is not less than 50% based on the total pore volume of the body and a total volume of pores having a diameter of not smaller than 10 μm is not greater than 20% based on the total pore volume of the body.
Claim 6
Dependent Claim
41 words
A cordierite honeycomb-structural body according to claim 1, wherein the average length of the cordierite crystals in the crystallographic axis c direction is 1-5 μm and at least 80% of the cordierite crystals have an aspect ratio of at least 1.5.
Claim 7
Dependent Claim
40 words
A cordierite honeycomb-structural body according to claim 1, wherein the cordierite crystal has an I ratio of at least 0.78 on a honeycomb wall surface, said surface being on a plane parallel to an extrusion direction of the honeycomb-structural body.
Claim 8
Independent Claim
139 words
A method for producing a cordierite honeycomb-structural body to be used as a catalyst carrier, comprising: mixing starting materials comprising talc having an average particle size of 5-100 μm, alumina having an average particle size of not greater than 2 μm, high-purity non-crystalline silica having an average particle size of not greater than 15 μm and other cordierite-forming materials to form a mixture consisting mainly of 42-56% by weight of SiO 2 , 30-45% by weight of Al 2 O 3 and 12-16% by weight of MgO calculated as oxides; kneading the mixture together with a plasticizer and an organic binder to form an extrudably plasticized batch; extruding the plasticized batch into a shaped article having a honeycomb structure by an extrusion-molding method; drying the shaped article; and firing the dried, shaped article at a temperature of 1,350°-1,440° C.
Claim 9
Independent Claim
139 words
A method for producing a cordierite honeycomb-structural body to be used as a catalyst carrier, comprising: mixing starting materials comprising talc having an average particle size of 5-100 μm, alumina having an average particle size of not greater than 2 μm, high-purity non-crystalline silica having an average particle size of not greater than 15 μm and other cordierite-forming materials to form a mixture consisting mainly of 42-56% by weight of SiO 2 , 30-45% by weight of Al 2 O 3 and 12-16% by weight of MgO calculated as oxides; kneading the mixture together with a plasticizer and an organic binder to form an extrudably plasticized batch; extruding the plasticized batch into a shaped article having a honeycomb structure by an extrusion-molding method; drying the shaped article; and firing the dried, shaped article at a temperature of 1,350°-1,440° C.
Claim 10
Dependent Claim
22 words
A method according to claim 7, wherein said alumina has an Na 2 O content of not greater than 0.12% by weight.
Claim 11
Dependent Claim
24 words
A method according to claim 7, wherein said other cordierite-forming materials comprise kaolin having an average particle size of not greater than 2 μm.
Claim 12
Dependent Claim
17 words
A method according to claim 7, wherein said talc has an average particle size of 7-50 μm.
Claim 13
Dependent Claim
20 words
A method according to claim 7, wherein the starting material mixture contains 8-20% by weight of the high-purity non-crystalline silica.
Claim 14
Dependent Claim
33 words
A method according to claim 7, wherein said talc has an average particle size of 5-15 μm and said high-purity non-crystalline silica has an average particle size of not greater than 12 μm.
Claim 15
Dependent Claim
17 words
A method according to claim 12, wherein said talc has an average particle size of 7-12 μm.
Claim 16
Dependent Claim
22 words
A method according to claim 12, wherein said high-purity non-crystalline silica has an average particle size of not larger than 8 μm.
References Cited (Backward Citations)
US3885977A
Cited
US3950175A
Cited
US3958058A
Cited
US4295892A
Cited
US4280845A
Cited
US4177307A
Cited
US4268311A
Cited
US4435512A
Cited
US4495300A
Cited
US4540671A
Cited
US4489774A
Cited
US4772580A
Cited
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