Patent classifications
C04B38/068
Manufacturing method of ceramic formed body
A manufacturing method of a ceramic formed body, including: a mixing step in which a raw material for forming a ceramic formed body is dryly mixed, and then, a liquid is added to the obtained dry mixture to wetly mix the mixture; a kneading step in which a mixture obtained in the mixing step is kneaded; an injection step in which supercritical carbon dioxide in the state of supercritical fluid is injected into a kneaded product obtained in the kneading step; and a forming step in which a forming raw material containing the supercritical carbon dioxide obtained in the kneading step and the injection step is extruded to form the ceramic formed body.
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.
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.
Conductive porous ceramic substrate and method of manufacturing same
The present invention relates to a conductive porous ceramic substrate and a method of manufacturing the same, and more particularly to a conductive porous ceramic substrate, in which a porous ceramic substrate used as a chuck or stage for fixing a thin semiconductor wafer substrate or display substrate through vacuum adsorption is imparted with antistatic performance so as to prevent the generation of static electricity, and a method of manufacturing the same.
Conductive porous ceramic substrate and method of manufacturing same
The present invention relates to a conductive porous ceramic substrate and a method of manufacturing the same, and more particularly to a conductive porous ceramic substrate, in which a porous ceramic substrate used as a chuck or stage for fixing a thin semiconductor wafer substrate or display substrate through vacuum adsorption is imparted with antistatic performance so as to prevent the generation of static electricity, and a method of manufacturing the same.
Method of producing honeycomb structured body
The present invention provides a method of producing a honeycomb structured body having excellent mechanical strength. The present invention relates to a method of producing a honeycomb structured body including a honeycomb fired body in which multiple through-holes are arranged longitudinally in parallel with one another with a partition wall therebetween, the method including: a raw material mixing step of preparing a raw material paste containing ceria-zirconia composite oxide particles, alumina particles, an inorganic binder, and inorganic fibers; a molding step of molding the raw material paste into a honeycomb molded body in which multiple through-holes are arranged longitudinally in parallel with one another with a partition wall therebetween; a drying step of drying the honeycomb molded body obtained in the molding step; and a firing step of firing the honeycomb molded body dried in the drying step into a honeycomb fired body, wherein the raw material mixing step includes pre-mixing of the inorganic binder and the inorganic fibers.
Method of producing honeycomb structured body
The present invention provides a method of producing a honeycomb structured body having excellent mechanical strength. The present invention relates to a method of producing a honeycomb structured body including a honeycomb fired body in which multiple through-holes are arranged longitudinally in parallel with one another with a partition wall therebetween, the method including: a raw material mixing step of preparing a raw material paste containing ceria-zirconia composite oxide particles, alumina particles, an inorganic binder, and inorganic fibers; a molding step of molding the raw material paste into a honeycomb molded body in which multiple through-holes are arranged longitudinally in parallel with one another with a partition wall therebetween; a drying step of drying the honeycomb molded body obtained in the molding step; and a firing step of firing the honeycomb molded body dried in the drying step into a honeycomb fired body, wherein the raw material mixing step includes pre-mixing of the inorganic binder and the inorganic fibers.
Pillar-shaped honeycomb structure and method for manufacturing same
A pillar-shaped honeycomb structure including an outer peripheral side wall, a plurality of first cells provided on an inner peripheral side of the outer peripheral side wall, the first cells extending from a first end surface to a second end surface, each opening on the first end surface and having a sealing portion with an average void ratio of 4% or less on the second end surface, and a plurality of second cells provided on the inner peripheral side of the outer peripheral side wall, the second cells extending from the first end surface to the second end surface, each having a sealing portion with an average void ratio of 4% or less on the first end surface and opening on the second end surface, the first cells and the second cells being alternately arranged adjacent to each other with a partition wall interposed therebetween.