摘要:
A sintering aid for promoting sintering of ceramic particles and fine particles that are the same materials as ceramic particles and have smaller average particle diameter are mixed to obtain a puddle. The average particle diameter of ceramic particles is preferably about in a range of 5 to 100 μm; the average particle diameter of the fine particles is preferably about in a range of 0.1 to 1.0 μm, and the average particle diameter of the sintering aid is preferably about in a range of 0.1 to 10 μm. As the sintering aid, for example, alumina is used. This puddle is extrusion molded into a honeycomb shape and the molded object is fired at a firing temperature lower than a temperature for sintering without mixing a sintering aid. The thermal conductivity of the obtained honeycomb structure 10 shows about 60% or more of the thermal conductivity of a fired body fired without adding a sintering aid to ceramic particles and shows about 12 W/m·K or more at 20° C.
摘要:
The present invention provides a method for producing a honeycomb structure which carries a catalyst component containing at least one element selected from the group consisting of alkali metals and alkaline earth metals and purifies exhaust emissions. The method of the invention includes: a starting material mixing step of mixing ceramic particles having a predetermined average particle size, fine particles being composed of the same material as the ceramic particles and having an average particle size smaller than the predetermined average particle size, and an erosion-resistant material or a precursor thereof which inhibits the catalyst component from eroding the ceramic particles more effectively than an oxide of the element contained in the ceramic particles, to prepare a puddle; a molding and firing step of molding the puddle into a molded body and firing the molded body to sinter the molded body and to allow a ceramic particle protection material composed of the erosion-resistant material or the precursor thereof to be present on the surface of the molded body; and a catalyst-carrying step of making the fired molded body to carry the catalyst component.
摘要:
The honeycomb structured body of the present invention is a honeycomb structured body in which a plurality of porous ceramic members are combined with one another through an adhesive layer, each of the porous ceramic members having a plurality of cells which are allowed to penetrate in a longitudinal direction with a wall portion therebetween and either one end of which is sealed, with a catalyst supporting layer being adhered to the wall portion, wherein an average pore diameter of the porous ceramic member is larger than an average particle diameter of particles constituting the catalyst supporting layer, and when a pore diameter distribution of the porous ceramic member and a particle diameter distribution of particles constituting the catalyst supporting layer are drawn with the pore diameter and the particle diameter being on the same axis, a pore volume in an overlapped area of both the distributions is about 10% or less to the entire pore volume of the porous ceramic member.
摘要:
The present invention provides a method for producing a honeycomb structure which carries a catalyst component containing at least one element selected from the group consisting of alkali metals and alkaline earth metals and purifies exhaust emissions. The method of the invention includes: a starting material mixing step of mixing ceramic particles having a predetermined average particle size, fine particles being composed of the same material as the ceramic particles and having an average particle size smaller than the predetermined average particle size, and an erosion-resistant material or a precursor thereof which inhibits the catalyst component from eroding the ceramic particles more effectively than an oxide of the element contained in the ceramic particles, to prepare a puddle; a molding and firing step of molding the puddle into a molded body and firing the molded body to sinter the molded body and to allow a ceramic particle protection material composed of the erosion-resistant material or the precursor thereof to be present on the surface of the molded body; and a catalyst-carrying step of making the fired molded body to carry the catalyst component.
摘要:
A honeycomb structured body of the present invention is a honeycomb structured body in which a plurality of porous ceramic members are combined with one another through an adhesive layer, each of the porous ceramic members having a plurality of cells which are allowed to penetrate in a longitudinal direction with a wall portion therebetween and either one end of which is sealed, with a catalyst supporting layer being adhered to the wall portion, wherein, supposing that the rate of the pore volume of pores having a pore diameter of 10 μm or less to the entire pore volume of the porous ceramic member is X1 (%), the porosity is Y1 (%) and the weight of the catalyst supporting layer is Z1 (g/l), these X1, Y1 and Z1 are allowed to satisfy the following expressions (1) and (2): X1≦20−Z1/10 (1), and Y1≧35+7Z1/40 (2) (where about 20≦Z1≦about 150).
摘要:
A sintering aid for promoting sintering of ceramic particles and fine particles that are the same materials as ceramic particles and have smaller average particle diameter are mixed to obtain a puddle. The average particle diameter of ceramic particles is preferably about in a range of 5 to 100 μm; the average particle diameter of the fine particles is preferably about in a range of 0.1 to 1.0 μm, and the average particle diameter of the sintering aid is preferably about in a range of 0.1 to 10 μm. As the sintering aid, for example, alumina is used. This puddle is extrusion molded into a honeycomb shape and the molded object is fired at a firing temperature lower than a temperature for sintering without mixing a sintering aid. The thermal conductivity of the obtained honeycomb structure 10 shows about 60% or more of the thermal conductivity of a fired body fired without adding a sintering aid to ceramic particles and shows about 12 W/m·K or more at 20° C.
摘要:
Ceramic particles, fine particles having smaller average particle diameter smaller than that of the ceramic particles and a reduction-resistant material are mixed to obtain a puddle. The reduction-resistant material is a material that is reduced by carbon at a higher temperature as compared with a temperature at which an oxide (for example, silica) of an element contained in the ceramic particles is reduced. The average particle diameter of the ceramic particles is preferably about in a range of 5 to 100 μm and the average particle diameter of the fine particles is preferably about in a range of 0.1 to 10 μm. The reduction-resistant material is, for example, alumina. This puddle is extrusion molded into a honeycomb filter and the molded object is sintered at about 1600 to 2200° C.
摘要:
A honeycomb structured body of the present invention is a honeycomb structured body in which a plurality of porous ceramic members are combined with one another through an adhesive layer, each of the porous ceramic members having a plurality of cells which are allowed to penetrate in a longitudinal direction with a wall portion therebetween and either one end of which is sealed, with a catalyst supporting layer being adhered to the wall portion, wherein, supposing that the rate of the pore volume of pores having a pore diameter of 10 μm or less to the entire pore volume of the porous ceramic member is X1 (%), the porosity is Y1 (%) and the weight of the catalyst supporting layer is Z1 (g/l), these X1, Y1 and Z1 are allowed to satisfy the following expressions (1) and (2): X1≦20−Z1/10 (1), and Y1≧35+7Z1/40 (2) (where about 20≦Z1≦about 150).