Patent classifications
C04B38/067
CERAMIC ELECTRONIC DEVICE, DIELECTRIC MATERIAL, AND MANUFACTURING METHOD OF CERAMIC ELECTRONIC DEVICE
A ceramic electronic device includes a dielectric layer and an internal electrode layer that are alternately stacked, wherein the dielectric layer contains yttria-stabilized zirconia and (Ca.sub.x1Ba.sub.x2Sr.sub.1-x1-x2)(Ti.sub.yZr.sub.1-y)O.sub.3 (0.6≤x1≤0.9, 0≤x2≤0.1, 0≤y≤0.1) as a main component, and wherein, in the dielectric layer, a concentration of the yttria-stabilized zirconia when a total amount of Ti and Zr is 100 mol % is 0.5 mol % or more and 5.0 mol % or less.
CERAMIC ELECTRONIC DEVICE, DIELECTRIC MATERIAL, AND MANUFACTURING METHOD OF CERAMIC ELECTRONIC DEVICE
A ceramic electronic device includes a dielectric layer and an internal electrode layer that are alternately stacked, wherein the dielectric layer contains yttria-stabilized zirconia and (Ca.sub.x1Ba.sub.x2Sr.sub.1-x1-x2)(Ti.sub.yZr.sub.1-y)O.sub.3 (0.6≤x1≤0.9, 0≤x2≤0.1, 0≤y≤0.1) as a main component, and wherein, in the dielectric layer, a concentration of the yttria-stabilized zirconia when a total amount of Ti and Zr is 100 mol % is 0.5 mol % or more and 5.0 mol % or less.
Batch compositions comprising pre-reacted inorganic particles and methods of manufacture of green bodies therefrom
Batch compositions containing pre-reacted inorganic spheroidal particles, small amount of fine inorganic particles (“fines”), and an extremely large amount of liquid vehicle. The batch compositions contain pre-reacted inorganic particles having a particle size distribution with 20 μm≤D50≤100 μm, D90≤100 μm, and D5≥10 μm; less than 20 wt % of fine inorganic particles (fines) whose particle distribution(s) have a median diameter of less than 5 μm; and a liquid vehicle in a weight percent (LV %≥28%) by super-addition to all inorganic particles in the batch composition. Fast extruding batch compositions having extremely high Tau Y/Beta ratios are provided. Green bodies, such as green honeycomb bodies and methods of manufacturing green honeycomb bodies are provided, as are other aspects.
Batch compositions comprising pre-reacted inorganic particles and methods of manufacture of green bodies therefrom
Batch compositions containing pre-reacted inorganic spheroidal particles, small amount of fine inorganic particles (“fines”), and an extremely large amount of liquid vehicle. The batch compositions contain pre-reacted inorganic particles having a particle size distribution with 20 μm≤D50≤100 μm, D90≤100 μm, and D5≥10 μm; less than 20 wt % of fine inorganic particles (fines) whose particle distribution(s) have a median diameter of less than 5 μm; and a liquid vehicle in a weight percent (LV %≥28%) by super-addition to all inorganic particles in the batch composition. Fast extruding batch compositions having extremely high Tau Y/Beta ratios are provided. Green bodies, such as green honeycomb bodies and methods of manufacturing green honeycomb bodies are provided, as are other aspects.
POROUS FIRED GRANULATED BODY AND METHOD FOR MANUFACTURING THE SAME
A porous fired granulated body is formed by consolidating numerous alumina particles to each other while letting mainly interconnected pores remain in network form across an entire cross section of a granulated body particle (11). The pores (13) have an inner diameter controlled by a droplet diameter of a pore forming agent and have numerous precipitated alumina crystals (15) formed on inner surfaces thereof. Manufacture is performed by spraying the pore forming agent (emulsion) onto a raw material to form a coating layer of the pore forming agent on a surface of the raw material particle and controlling the inner diameter of the pores. A porous fired granulated body of alumina having a high specific surface area and having higher strength for the same specific surface area can thus be provided by a simple manufacturing method.
POROUS FIRED GRANULATED BODY AND METHOD FOR MANUFACTURING THE SAME
A porous fired granulated body is formed by consolidating numerous alumina particles to each other while letting mainly interconnected pores remain in network form across an entire cross section of a granulated body particle (11). The pores (13) have an inner diameter controlled by a droplet diameter of a pore forming agent and have numerous precipitated alumina crystals (15) formed on inner surfaces thereof. Manufacture is performed by spraying the pore forming agent (emulsion) onto a raw material to form a coating layer of the pore forming agent on a surface of the raw material particle and controlling the inner diameter of the pores. A porous fired granulated body of alumina having a high specific surface area and having higher strength for the same specific surface area can thus be provided by a simple manufacturing method.
TABLETED ALPHA-ALUMINA CATALYST SUPPORT
A tableted catalyst support, characterized by an alpha-alumina content of at least 85 wt.-%, a pore volume of at least 0.40 mL/g, as determined by mercury porosimetry, and a BET surface area of 0.5 to 5.0 m.sup.2/g. The tableted catalyst support is an alpha-alumina catalyst support obtained with high geometrical precision and displaying a high overall pore volume, thus allowing for impregnation with a high amount of silver, while exhibiting a surface area sufficiently large so as to provide optimal dispersion of catalytically active species, in particular metal species. The invention further provides a process for producing a tableted alpha-alumina catalyst support, which comprises i) forming a free-flowing feed mixture comprising, based on inorganic solids content, at least 50 wt.-% of a transition alumina; ii) tableting the free-flowing feed mixture to obtain a compacted body; and iii) heat treating the compacted body at a temperature of at least 1100° C., preferably at least 1300° C., more preferably at least 1400° C., in particular at least 1450° C., to obtain the tableted alpha-alumina catalyst support. The invention moreover relates to a compacted body obtained by tableting a free-flowing feed mixture which comprises, based on inorganic solids content, at least 50 wt.-% of a transition alumina having a loose bulk density of at most 600 g/L, a pore volume of at least 0.6 mL/g, as determined, and a median pore diameter of at least 15 nm. The invention moreover relates to a shaped catalyst body for producing ethylene oxide by gas-phase oxidation of ethylene, comprising at least 15 wt.-% of silver, relative to the total weight of the catalyst, deposited on the tableted alpha-alumina catalyst support. The invention moreover relates to a process for producing ethylene oxide by gas-phase oxidation of ethylene, comprising reacting ethylene and oxygen in the presence of the shaped catalyst body.
TABLETED ALPHA-ALUMINA CATALYST SUPPORT
A tableted catalyst support, characterized by an alpha-alumina content of at least 85 wt.-%, a pore volume of at least 0.40 mL/g, as determined by mercury porosimetry, and a BET surface area of 0.5 to 5.0 m.sup.2/g. The tableted catalyst support is an alpha-alumina catalyst support obtained with high geometrical precision and displaying a high overall pore volume, thus allowing for impregnation with a high amount of silver, while exhibiting a surface area sufficiently large so as to provide optimal dispersion of catalytically active species, in particular metal species. The invention further provides a process for producing a tableted alpha-alumina catalyst support, which comprises i) forming a free-flowing feed mixture comprising, based on inorganic solids content, at least 50 wt.-% of a transition alumina; ii) tableting the free-flowing feed mixture to obtain a compacted body; and iii) heat treating the compacted body at a temperature of at least 1100° C., preferably at least 1300° C., more preferably at least 1400° C., in particular at least 1450° C., to obtain the tableted alpha-alumina catalyst support. The invention moreover relates to a compacted body obtained by tableting a free-flowing feed mixture which comprises, based on inorganic solids content, at least 50 wt.-% of a transition alumina having a loose bulk density of at most 600 g/L, a pore volume of at least 0.6 mL/g, as determined, and a median pore diameter of at least 15 nm. The invention moreover relates to a shaped catalyst body for producing ethylene oxide by gas-phase oxidation of ethylene, comprising at least 15 wt.-% of silver, relative to the total weight of the catalyst, deposited on the tableted alpha-alumina catalyst support. The invention moreover relates to a process for producing ethylene oxide by gas-phase oxidation of ethylene, comprising reacting ethylene and oxygen in the presence of the shaped catalyst body.
CERAMIC ARTICLES MADE FROM CERAMIC BEADS WITH OPEN POROSITY
A ceramic article and method of manufacturing. The ceramic article comprises a porous ceramic material having a microstructure comprising an interconnected network of porous spheroidal ceramic beads. The microstructure has a total open porosity defined as the sum of an open intrabead porosity of the beads and an interbead porosity defined by interstices between the beads in the interconnected network. The microstructure has a bimodal pore size distribution having an intrabead peak corresponding to the open intrabead porosity and an interbead peak corresponding to the interbead porosity. An intrabead median pore size of the intrabead porosity is less than an interbead median pore size of the interbead porosity.
CERAMIC ARTICLES MADE FROM CERAMIC BEADS WITH OPEN POROSITY
A ceramic article and method of manufacturing. The ceramic article comprises a porous ceramic material having a microstructure comprising an interconnected network of porous spheroidal ceramic beads. The microstructure has a total open porosity defined as the sum of an open intrabead porosity of the beads and an interbead porosity defined by interstices between the beads in the interconnected network. The microstructure has a bimodal pore size distribution having an intrabead peak corresponding to the open intrabead porosity and an interbead peak corresponding to the interbead porosity. An intrabead median pore size of the intrabead porosity is less than an interbead median pore size of the interbead porosity.