摘要:
A process for producing a ceramic structure, which comprises adding an organic assistant to a ceramic raw material mixture, kneading them to obtain a readily formable bullet, and extruding the readily formable bullet to obtain a ceramic structure, wherein the organic assistant is composed mainly of an organic compound giving a haze of 10 to 90% when made into a 5 weight % aqueous dispersion. According to the process, the load to the extruder is small and a ceramic structure can be produced at high shapability and a high productivity.
摘要:
A method of producing a cordierite ceramic honeycomb including the steps of: preparing raw materials becoming cordierite and forming agents; adding the forming agents into the raw materials for cordierite generation; mixing the forming agents and the raw materials to obtain a raw material batch; extruding the raw material batch to obtain a formed body; drying the formed body; and sintering the formed body after drying; so as to obtain a honeycomb structural body having a cordierite crystal phase as a main ingredient. In this method, at the sintering step, a temperature descending rate at least from a maximum temperature to 1300° C. is not larger than 100° C./hour.
摘要:
There is disclosed a ceramic structure which comprises a material having a controlled pore distribution and including cordierite as the main crystal phase. In the pore distribution, the volume of pores having pore diameters smaller than 20 μm accounts for 15% or less of the total pore volume, and the volume of pores having pore diameters of 20 to 100 μm accounts for 70% or more of the total pore volume. This ceramic structure is suitable for realizing a ceramic catalyst body which has excellent purification efficiency, is reduced in pressure loss, and is mountable even in a limited space.
摘要:
A process for producing a honeycomb structure, which comprises adding water to a mixed raw material of a raw material powder and a binder, kneading the mixture to obtain a plastic mixture, molding the plastic mixture into a honeycomb shape to obtain a green honeycomb structure, drying the structure by a step including hot-air drying, and firing the resulting dried honeycomb structure, wherein the binder contains hydroxypropyl methyl cellulose as a major component. The process can produce a crack-free high-quality honeycomb structure rapidly at a low cost.
摘要:
A ceramic honeycomb catalyst carrier wherein a porosity is 20% or less and an average surface roughness (Ra) of a partition wall of the carrier is 0.5 &mgr;m or more is obtained by forming ceramic raw materials to obtain a ceramic honeycomb formed body; drying the ceramic honeycomb formed body to obtain a ceramic honeycomb dried-up body; roughening a surface of the partition wall of the ceramic honeycomb dried-up body by exposing the ceramic honeycomb dried-up body in an airflow in which polishing powders are included; and sintering the ceramic honeycomb dried-up body after a surface treatment, or, by forming ceramic raw materials to obtain a ceramic honeycomb formed body; drying and sintering the ceramic honeycomb formed body to obtain a ceramic honeycomb sintered body; and roughening a surface of the partition wall of the ceramic honeycomb sintered body by exposing the ceramic honeycomb sintered body in an airflow or a water flow in which polishing powders are included.
摘要:
A process for producing a cordierite-based ceramic honeycomb structure, includes kneading raw materials for cordierite with a forming aid to obtain a raw material batch, subjecting the raw material batch to obtain a honeycomb structure, and subjecting the honeycomb structure to drying and firing in this order to obtain a ceramic honeycomb structure whose crystal phase is composed mainly of cordierite. The raw material batch contains 65% by weight or more of raw materials for cordierite, comprising talc, kaolin and aluminum hydroxide and having crystal water. The kaolin has an average particle diameter of 5 &mgr;or more and a BET specific surface area of 10 m2/g or less and is contained in the raw material batch in an amount of 10% or more by weight. Formability during extruding, particularly lubricity and shape stability, are improved, for producing cordierite-based ceramic honeycomb structure having thin partition walls and high cell density, and improved mechanical strength (isostatic fracture strength) and improved catalyst coatability.
摘要:
A method for manufacturing a porous ceramic structure which comprises: mixing a ceramic material, a foamed resin and, if necessary, a forming auxiliary; forming the mixture; and then firing the thus formed body, wherein: a resin of an outer shell of the foamed resin is constituted of a copolymer containing 60 wt % or more of acrylonitrile and 40 wt % or less of methyl methacrylate.
摘要:
There is disclosed a honeycomb structure including a honeycomb structure section including: porous partition walls to divide and form a plurality of cells which extend from one end surface to the other end surface and become through channels of a fluid; and an outer peripheral wall positioned in an outermost periphery. The partition walls and the outer peripheral wall contain silicon carbide particles as an aggregate, and silicon as a binder to bind the silicon carbide particles, thicknesses of the partition walls are from 50 to 200 μm, a cell density is from 50 to 150 cells/cm2, an average particle diameter of silicon carbide as the aggregate is from 3 to 40 μm, and a volume resistivity at 400° C. is from 1 to 40 Ωcm.
摘要翻译:公开了一种蜂窝结构体,其包括蜂窝结构部分,该蜂窝结构部分包括:多孔分隔壁,用于分隔并形成从一个端面延伸到另一端面的多个单元,并且通过流体通道; 以及位于最外周的外周壁。 分隔壁和外周壁包含作为骨料的碳化硅颗粒和作为粘结剂的硅作为结合碳化硅颗粒的分隔壁,隔壁的厚度为50至200μm,电池密度为50至150个/ cm 2,作为骨料的碳化硅的平均粒径为3〜40μm,400℃下的体积电阻率为1〜40Ω·cm。
摘要:
In a hepatic disease-evaluating apparatus, an indicator calculating unit calculates an index indicating the degree of hepatic fibrosis from amino acid concentration data to be evaluated including amino acid concentration value, based on one or more indices of fractional expression having amino acid concentration as variable. A disease state evaluating unit evaluates the disease state of the hepatic disease to be evaluated, based on the index value.
摘要:
In a hepatic disease-evaluating apparatus, an indicator calculating unit calculates an index indicating the degree of hepatic fibrosis from amino acid concentration data to be evaluated including amino acid concentration value, based on one or more indices of fractional expression having amino acid concentration as variable. A disease state evaluating unit evaluates the disease state of the hepatic disease to be evaluated, based on the index value.