Abstract: There is provided a honeycomb structure in which the structure is not segmented, or a smaller number of segments are integrated to suppress a local temperature rise and to reduce breakage by thermal stress at the time of use, and a method of manufacturing the structure. There is disclosed a honeycomb structure 1 comprising: a large number of cells 3 partitioned by cell walls 2 and extending through an axial direction. A flow channel separator 6 is formed in the honeycomb structure 1. There is disclosed a method of manufacturing the honeycomb structure 1 in which the flow channel separator 6 is formed by extrusion. There is disclosed a method of manufacturing the honeycomb structure 1 in which the flow channel separator 6 is formed by clogging.

Abstract: A honeycomb filter includes a honeycomb-shaped filter base having a plurality of through holes and a sealing member fixed on end surfaces of the filter base in which the through holes are open. The through holes of the filter base are clogged with the sealing member in a checker flag form on each end surface so as to clog the through holes differently from the through holes sealed on the opposite end surface. The sealing member 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 said sealing member and said filter base is 0.5×10?6/° C. or less. This honeycomb filter has high filtration efficiency, and very high thermal shock resistance and has high bonding strength between the sealing member and the filter base and a low pressure loss.

Abstract: A honeycomb filter for exhaust gas purification, possessing a honeycomb structure (1) having a plurality of through-holes which are separated from each other by porous partition walls and plugged alternately at the exhaust gas inlet face (2) and the exhaust gas outlet face (3), wherein the honeycomb structure (1) has a slit (5) possessing an opening at least at the exhaust gas inlet face (2), and the slit (5) is partially filled with a filler (6) in a depth of 3 to 25 times the width (5d) of slit from the exhaust gas inlet face (3) toward a flow direction (10) of exhaust gas and a gap (5e) is formed inside from a portion of the slit filled with the filler (6). This honeycomb filter for exhaust gas purification has high purification ability, yet possesses high thermal shock resistance, and can be used continuously over a long period.

Abstract: There is provided a honeycomb structure in which the structure is not segmented, or a smaller number of segments are integrated to suppress a local temperature rise and to reduce breakage by thermal stress at the time of use, and a method of manufacturing the structure. There is disclosed a honeycomb structure 1 comprising: a large number of cells 3 partitioned by cell walls 2 and extending through an axial direction. A flow channel separator 6 is formed in the honeycomb structure 1. There is disclosed a method of manufacturing the honeycomb structure 1 in which the flow channel separator 6 is formed by extrusion. There is disclosed a method of manufacturing the honeycomb structure 1 in which the flow channel separator 6 is formed by clogging.

Abstract: A honeycomb filter is composed mainly of silicon carbide or of metallic silicon and silicon carbide; the filter being formed by bonding a plurality of honeycomb segments each of which has a plurality of through-holes being partitioned by porous partition walls. The filter is plugged alternately at the exhaust gas inlet face and exhaust gas outlet face of honeycomb segments. Each two adjacent honeycomb segments are contacted with each other at each a portion of their sides facing each other. They are bonded with each other at least at part of each portion of said sides other than the contacted portion through a bonding material having a strength lower than that of a basal body of honeycomb segment. Thus, the thermal stresses generated among the respective portions constituting the filter is reduced. The generation of cracks, etc. can be also prevented considerably.

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 honeycomb filter for exhaust gas purification, possessing a honeycomb structure (1) having a plurality of through-holes which are separated from each other by porous partition walls and plugged alternately at the exhaust gas inlet face (2) and the exhaust gas outlet face (3), wherein the honeycomb structure (1) has a slit (5) possessing an opening at least at the exhaust gas inlet face (2), and the slit (5) is partially filled with a filler (6) in a depth of 3 to 25 times the width (5d) of slit from the exhaust gas inlet face (3) toward a flow direction (10) of exhaust gas and a gap (5e) is formed inside from a portion of the slit filled with the filler (6). This honeycomb filter for exhaust gas purification has high purification ability, yet possesses high thermal shock resistance, and can be used continuously over a long period.

Abstract: A honeycomb filter (10) obtained by bonding a plurality of honeycomb segments (4, 5) each having a plurality of through-holes (21) which are separated from each other by porous partition walls (20) and which are plugged alternately at the exhaust gas inlet face (16) and exhaust gas outlet face (14) of honeycomb segment, wherein each two adjacent honeycomb segments (4, 5) are contacted with each other at each a portion of their sides (6, 7) facing each other and are bonded with each other at least at part of each portion of said sides (6, 7) other than the contacted portion (8, 9) via a bonding material having a strength lower than that of a basal body of honeycomb segment. With this honeycomb filter, the thermal stresses generated among the respective portions constituting the filter is reduced and the generation of cracks, etc. can be prevented considerably, and this honeycomb filter functions well particularly.

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: A production method of a honeycomb structure is provided. The production method of a thin wall cordierite honeycomb structure having cordierite as the main component of the crystalline phase includes: adding a forming auxiliary agent to a cordierite material to obtain a mixture, kneading the mixture to obtain a material batch, forming the material batch by extrusion to form a honycomb compact, drying the honeycomb compact to obtain a dried body, and firing the dried body. The cordierite material batch contains 65% by weight or more flat plate-like cordierite raw material including crystal water made from talc, kaolin and aluminum hydroxide with the BET specific surface areas for the cordierite raw materials being 7 to 18 m.sup.2 /g of talc, 14 to 22 m.sup.2 /g of kaolin and 6 to 18 m.sup.2 /g of aluminum hydroxide.

Abstract: Ceramic materials to be insert-cast are disclosed, which each contain not less than 65% by volume of aluminum titanate as a crystalline phase, and have an average particle diameter of crystals thereof being not less than 10 .mu.m, Young's modulus of 50 to 2,000 kgf/mm.sup.2, compression strength of 5 to 40 kgf/mm.sup.2, and porosity of 5 to 35%. Ceramic port liners are also disclosed, which are free from cracking due to compression force during insert-casting, peeling-off during use, and facilitate insert-casting. To attain this, a reinforcement which meets either one or both of requirements that differences in coefficient of thermal expansion at 800.degree. C. and Young's modulus between the reinforcement and a material constituting the port liner body are in a range of .+-.0.1% and in a range of .+-.1,000 kgf/mm.sup.2, respectively, is filled into a depressed portion at an outer peripheral surface of the port liner body to form an integrated structure with a flat or swelled surface.

Abstract: A porous ceramic honeycomb filter having a chemical composition consisting of, as main components, 42-56 wt % SiO.sub.2, 30-45 wt % Al.sub.2 O.sub.3, and 12-16 wt % MgO and containing cordierite as a main component of a crystalline phase. The porous ceramic honeycomb filter has a porosity of at least 40% and not greater than 55%. The volume of pores having a diameter not larger than 2 .mu.m in the filter is not larger than 0.015 cc/g to thereby improve the collecting time with low pressure loss and high collecting efficiency.

Abstract: A ceramic material for use in insert-casting, which contains not less than 65% by volume of aluminum titanate as a crystalline phase. The average particle diameter of crystals of the aluminum titanate is not less than 10 .mu.m, and not more than 20% by volume of a glass phase containing a rare earth element in an amount of 0.5 to 16% by weight when calculated in the form of an oxide is contained. Young's modulus is 50 to 2,000 kgf/mm.sup.2. A process for producing the same is also disclosed, which includes the steps of preparing a powder by mixing a material, as an Al.sub.2 O.sub.3 source material, containing not more than 96% by weight of Al.sub.2 O.sub.3 and having an average particle size of not less than 3 .mu.m, a material having an average particle diameter of not more than 3 .mu.m as a TiO.sub.2 source material, and a given rare earth element in an amount of 1.8% by weight when calculated in the form of an oxide, shaping the powder, and drying and firing the shaped body.

Abstract: Ceramic materials to be insert-cast are disclosed, which each contain not less than 65% by volume of aluminum titanate as a crystalline phase, and have an average particle diameter of crystals thereof being not less than 10 .mu.m, Young's modulus of 50 to 2,000 kgf/mm.sup.2, compression strength of 5 to 40 kgf/mm.sup.2, and porosity of 5 to 35%. Ceramic port liners are also disclosed, which are free from cracking due to compression force during insert-casting, peeling-off during use, and facilitate insert-casting. To attain this, a reinforcement which meets either one or both of requirements that differences in coefficient of thermal expansion at 800.degree. C. and Young's modulus between the reinforcement and a material constituting the port liner body are in a range of .+-.0.1% and in a range of .+-.1,000 kgf/mm.sup.2, respectively, is filled into a depressed portion at an outer peripheral surface of the port liner body to form an integrated structure with a flat or swelled surface.

Abstract: Cordierite honeycomb structural bodies having coefficients of thermal expansion of not more than 1.0x10.sup.-6, an improved thermal shock resistance, a very small leakage amount and an improved heat exchanging efficiency are provided by using very fine particles of kaolin and talc to restrict a total pore volume of a given pore diameter to a given range. The cordierite honeycomb structural bodies are useful in broader fields than conventional ones.

Abstract: Novel processes have been developed by the present invention for producing hollow ceramic articles. Such ceramic articles are produced by using a water-absorbable mold having water non-permeable faces on an inner surface of the mold at locations corresponding to valve holes. The thickness of a ceramic layer deposited on the inner surface of the mold is controlled by measuring an amount of a lowered liquid surface level of the slurry near a slurry-pouring opening of the mold. Open ends of a hollow ceramic article are formed by cutting corresponding closed ends after deposition of the slurry and firing. A uniform thickness of a slurry deposited onto the inner surface of the mold can be attained by rotating the mold around an arbitrary rotary axis at a rotation speed of 1 to 60 rpm. All ceramic material contained in the slurry fed inside the mold may be deposited on the inner surface of the mold while the mold is being rotated or swung.

Abstract: In a method for effectively producing ceramic manifolds for thermally insulating exhaust channels, an intermediate product is first formed by drain casting which includes a main ceramic pipe having a plurality of branch pipes extending therefrom whose ends are connected together by elongated connection members in the form of thin plates or bars. Thereafter, the intermediate product is fired and the ends of the branch pipes are then cut off together with the connection members. In this manner, even ceramic pipes complicated in shape readily can be produced by preventing strains and deformations which would otherwise occur during firing of the intermediate product.

Abstract: A heat insulating ceramic insert-cast article for an internal combustion engine, comprising a ceramic liner and a metallic member enclosing an outer periphery of the ceramic liner. The ceramic liner is adapted to contact exhaust gases. A joint boundary between the ceramic liner and the metallic member is constituted by contact faces at which the ceramic liner contacts the metallic member and heat insulating air layers at which the ceramic liner and the metallic member do not contact each other. A process for producing such a heat insulating ceramic insert-cast article is also disclosed. First, the outer periphery of the ceramic liner is covered with the heat insulating layer which is partially formed with cuts, and then the ceramic liner is enclosed with a molten metal in the state that the ceramic liner is covered with the layer.