Abstract: There is disclosed a honeycomb ceramics filter, wherein an average pore diameter X (&mgr;m) and partition wall thickness W (&mgr;m) of the filter satisfy a relation of 10≧W/X. According to this filter, while a predetermined trapping efficiency is maintained, a pressure loss can be prevented from increasing to be not less than a predetermined pressure loss even with use for a long period.

Abstract: A honeycomb filter comprises a honeycomb-shaped filter base (2) having a plurality of through holes (4a, 4b) and a sealing member (1) fixed on end surfaces of the filter base (2) in which the through holes (4a, 4b) are open, wherein in which said through holes of said filter base are clogged with said sealing member in a checker flag form on one end surface, and are clogged with the sealing member in a checker flag form on the other end surface so as to clog the through holes different from the through holes sealed on said one end surface, and the sealing member (1) is a sheet-shaped fired body with a thickness of 3 mm or less, and a difference in coefficient of thermal expansion at temperatures of 40 to 800° C. between the sealing member (1) and the filter base (2) is 0.5×10−6/° C. or less. This honeycomb filter has high filtration efficiency and very high thermal shock resistance, and also has high bonding strength between the sealing member and the filter base, and a low pressure loss.

Abstract: 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.

Abstract: A low thermal expansion cordierite ceramic honeycomb is obtained by controlling crystal phases in such a manner that a cordierite crystal phase is not lower than 60% and an indialite crystal phase is not greater than 30%, wherein a sum of the cordierite crystal phase and the indialite crystal phase is not lower than 85%. Moreover, to this end, a method of producing the low thermal expansion cordierite ceramic honeycomb, having the steps of mixing raw materials and forming agents to obtain a raw materials batch, extruding and drying the raw material batch to obtain a formed body, and sintering the formed body, is characterized in that, during the sintering step, a temperature descending rate at least from a maximum temperature to 1300° C. is not greater than 100° C./hour.

Abstract: A ceramics structure body having chemical composition of 42 to 56 wt % of SiO2, 30 to 45 wt % of Al2O3 and 12 to 16 wt % of MgO, crystalline phase mainly composed of cordierite, a porosity of 55 to 65%, an average pore size of 15 to 30 &mgr;m; and the total area of pores exposed on surfaces of partition walls constituting the honeycomb ceramics structure body being 35% or more of the total area of partition wall surfaces. Fifteen to 25 wt % of graphite and 5 to 15 wt % of a synthetic resin are added as a pore forming agent to a cordierite-forming raw material; the resultant is kneaded and molded into a honeycomb shape; and the resultant is dried and fired to produce above-mentioned honeycomb ceramics structure body. According to this honeycomb ceramics structure body, a low pressure loss and a high collection efficiency can be attained.

Abstract: 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.

Abstract: A honeycomb structure constituted by

Abstract: There is here disclosed a method for manufacturing a porous ceramic structure which can produce a high porosity ceramic structure as well as a low porosity ceramic structure without causing cracks at the time of firing.

Abstract: There are provided a porous honeycomb structure body capable of satisfying a pressure loss and isostatic strength which are mutually contradictory properties simultaneously and a method for manufacturing the same. In a porous honeycomb structure body having partition walls which contain cordierite as a primary crystal phase and have a porosity of 40 to 75% and an average pore diameter of 10 to 50 &mgr;m, porosity and an average pore diameter in a center portion of the structure body are made larger than porosity and an average pore diameter in a peripheral portion of the structure body.

Abstract: There is a method of manufacturing a ceramic structure in which a ceramics raw material, a prefoamed resin foam, and a forming aid if needed are mixed together to prepare a mixture, then the mixture is formed into a formed body, and subsequently the formed body is fired to obtain a porous ceramic structure. According to the manufacturing method, a ceramic structure having a high porosity can be obtained, without using a large amount of flammable powder.

Abstract: The raw materials for forming a cordierite composition are dissolved into water with a dispersing agent to prepare a slurry, and the thus prepared slurry is passed through the sieve having a mesh of 45 &mgr;m or less. After that, the slurry after sieving is dried by means of the spray drying to obtain dry powders, and the batch for forming is obtained by using the dry powders. Or, the batch for forming is obtained by the filter pressing. That is to say, the batch for forming is obtained by using the raw material powders which are passed through the sieve in a wet state. Therefore, it is possible to prevent agglutination of the raw material particles and to remove the coarse raw material particles effectively. As a result, if the extrusion molding is performed by using the thus obtained batch for forming, it is possible to form the ceramic honeycomb structural body having an extremely thin wall thickness with no defects.

Abstract: 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.

Abstract: A porous honeycomb filter made from a material containing cordierite, of which pore distribution is controlled, as the primary crystalline phase. The pore distribution is such that the volume of a pore with a diameter of below 10 &mgr;m is 15% or less of the total pore volume, the volume of a pore with a diameter of 10 to 50 &mgr;m is 75% or more of the total pore volume, and the volume of a pore with a diameter of above 50 &mgr;m is 10% or less of the total pore volume. This porous honeycomb filter has a high collection efficiency for fine particles (particulates), or the like, and can prevent increase in pressure loss due to the plugging of pores, and particularly can exploit the characteristics thereof for diesel engines that use recent high-pressure fuel injection, common rails, etc.

Abstract: 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.

Abstract: A cordierite material batch is incorporated with 2 to 6 wt. % of binder reversibly gelling under heat. The binder is composed of a binder (A) and a binder (B), where 2% aqueous solution of the binder (A) has a viscosity of 5000 cP or less at 20° C., 2% aqueous solution of the binder (B) has a viscosity of 20000 cP or more at 20° C., and binder (A)/binder (B) (wt. ratio) is 10/90 to 50/50. According to the method, there can be provided a cordierite-based ceramic honeycomb structure suitable for mass production and giving the structure of thin wall by improving formability of the cordierite body (in particular, lubricity) at the time of extrusion.

Abstract: 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.

Abstract: The raw materials for forming a cordierite composition are dissolved into water with a dispersing agent to prepare a slurry, and the thus prepared slurry is passed through the sieve having a mesh of 45 &mgr;m or less. After that, the slurry after sieving is dried by means of the spray drying to obtain dry powders, and the batch for forming is obtained by using the dry powders. Or, the batch for forming is obtained by the filter pressing. That is to say, the batch for forming is obtained by using the raw material powders which are passed through the sieve in a wet state. Therefore, it is possible to prevent agglutination of the raw material particles and to remove the coarse raw material particles effectively. As a result, if the extrusion molding is performed by using the thus obtained batch for forming, it is possible to form the ceramic honeycomb structural body having an extremely thin wall thickness with no defects.

Abstract: 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.

Abstract: A picture processor for a video conference device, etc., can be used easily by carrying it into a room other than the video conference room, has an object of enabling the display of the input picture to be switched freely even if the picture of the line drawing is displayed together with the input picture. The picture of a line drawing, etc., is held at the corresponding position even in cases where the display of the input picture is switched by updating the input picture data, which is stored in the input picture memory 40, on the basis of the line drawing data and by writing the picture expressed with the line drawing data directly in the input picture, which is stored in the input picture memory 40.

Abstract: A picture processor for a video conference device, etc., can be used easily by carrying it into a room other than the video conference room, has an object of enabling the display of the input picture to be switched freely even if the picture of the line drawing is displayed together with the input picture. The picture of a line drawing, etc., is held at the corresponding position even in cases where the display of the input picture is switched by updating the input picture data, which is stored in the input picture memory 40, on the basis of the line drawing date and by writing the picture expressed with the line drawing data directly in the input picture, which is stored in the input picture memory 40.