A ceramic precursor batch composition comprising inorganic ceramic-forming ingredients, a binder, an aqueous solvent and a heteroatom polyol agent. The heteroatom polyol agent can be represented by X(R) where X is at least one of S, N, and P, and R is at least two of CH.sub.3, CH.sub.2CH.sub.2OH, CH.sub.2CH.sub.2CH.sub.2OH, CH.sub.2(CHOH)CH.sub.3, C(CH.sub.2OH).sub.1-3, CH.sub.2OH, CH(CH.sub.2OH)CHOH, C(O)(CHOH).sub.1-4CH.sub.2OH, and CH.sub.2CH.sub.2CH.sub.2OCH.sub.3. The presence of the heteroatom polyol agent provides a composition with a lower viscosity and/or a greater batch stiffening temperature (T.sub.onset) allowing for increased rates of extrusion. Methods for producing a ceramic honeycomb body using this ceramic precursor batch composition are also provided.

A ceramic precursor batch composition comprising inorganic ceramic-forming ingredients, a binder, an aqueous solvent and a heteroatom polyol agent. The heteroatom polyol agent can be represented by X(R) where X is at least one of S, N, and P, and R is at least two of CH.sub.3, CH.sub.2CH.sub.2OH, CH.sub.2CH.sub.2CH.sub.2OH, CH.sub.2(CHOH)CH.sub.3, C(CH.sub.2OH).sub.1-3, CH.sub.2OH, CH(CH.sub.2OH)CHOH, C(O)(CHOH).sub.1-4CH.sub.2OH, and CH.sub.2CH.sub.2CH.sub.2OCH.sub.3. The presence of the heteroatom polyol agent provides a composition with a lower viscosity and/or a greater batch stiffening temperature (T.sub.onset) allowing for increased rates of extrusion. Methods for producing a ceramic honeycomb body using this ceramic precursor batch composition are also provided.

The honeycomb catalyst body is equipped with a honeycomb structure body having partition walls that define a plurality of cells extending from a first end face as one of the end faces to a second end face as the other end face and serving as through channels of a fluid. The partition walls each have a base layer containing from 50 to 90 mass % of zeolite and a coat layer with which the surface of the base layer 11 is coated with a thickness of from 1 to 50 μm. The coat layer is either a coat layer (A) containing from 1 to 5 mass % vanadia and titania or a coat layer (B) containing from 1 to 5 mass % vanadia and a composite oxide of titania and tungsten oxide.

The honeycomb catalyst body is equipped with a honeycomb structure body having partition walls that define a plurality of cells extending from a first end face as one of the end faces to a second end face as the other end face and serving as through channels of a fluid. The partition walls each have a base layer containing from 50 to 90 mass % of zeolite and a coat layer with which the surface of the base layer 11 is coated with a thickness of from 1 to 50 μm. The coat layer is either a coat layer (A) containing from 1 to 5 mass % vanadia and titania or a coat layer (B) containing from 1 to 5 mass % vanadia and a composite oxide of titania and tungsten oxide.

A method for producing a ceramic honeycomb structure comprising a ceramic honeycomb body having large numbers of longitudinal cells partitioned by porous cell walls having porosity of 50% or more, and a peripheral wall formed on a peripheral surface of the ceramic honeycomb body, comprising the steps of extruding moldable ceramic material to form a honeycomb-structured ceramic green body; machining a peripheral portion of the green body or a sintered body obtained from the green body to remove part of cell walls in the peripheral portion to obtain a ceramic honeycomb body having longitudinal grooves on a peripheral surface; applying colloidal metal oxide to a peripheral surface of the ceramic honeycomb body and drying it, and then applying a coating material comprising ceramic aggregate having an average particle size of 1 μm or more to form the peripheral wall.

A method for producing a ceramic honeycomb structure comprising a ceramic honeycomb body having large numbers of longitudinal cells partitioned by porous cell walls having porosity of 50% or more, and a peripheral wall formed on a peripheral surface of the ceramic honeycomb body, comprising the steps of extruding moldable ceramic material to form a honeycomb-structured ceramic green body; machining a peripheral portion of the green body or a sintered body obtained from the green body to remove part of cell walls in the peripheral portion to obtain a ceramic honeycomb body having longitudinal grooves on a peripheral surface; applying colloidal metal oxide to a peripheral surface of the ceramic honeycomb body and drying it, and then applying a coating material comprising ceramic aggregate having an average particle size of 1 μm or more to form the peripheral wall.

The honeycomb filter of the present invention comprises a ceramic honeycomb substrate formed from a porous body of sintered ceramic particles, and a filter layer formed on the surface of the cell walls, wherein a portion of the filter layer penetrates from the surface of the cell walls into pores formed by the ceramic particles to form inter-particle filtration bodies, these inter-particle filtration bodies are formed from a plurality of spherical ceramic particles and crosslinking bodies which bind the spherical ceramic particles to each other, and the spherical ceramic particles and the crosslinking bodies form a three-dimensional network structure.

The honeycomb filter of the present invention comprises a ceramic honeycomb substrate formed from a porous body of sintered ceramic particles, and a filter layer formed on the surface of the cell walls, wherein a portion of the filter layer penetrates from the surface of the cell walls into pores formed by the ceramic particles to form inter-particle filtration bodies, these inter-particle filtration bodies are formed from a plurality of spherical ceramic particles and crosslinking bodies which bind the spherical ceramic particles to each other, and the spherical ceramic particles and the crosslinking bodies form a three-dimensional network structure.

A filter for the filtration of a fluid, such as a liquid, includes or is composed of a support element made of a porous ceramic material, the element exhibiting a tubular or parallelepipedal shape delimited by an external surface and including, in its internal portion, a set of adjacent channels with axes parallel to one another and separated from one another by walls of the porous inorganic material, in which at least a portion of the channels and/or at least a portion of the external surface are covered with a porous separating membrane layer, wherein the separating membrane layer is made of a material essentially composed of silicon carbide (SiC), and the content by weight of elemental nitrogen of the layer constituting the porous separating membrane layer is between 0.1% and 2%.

A filter for the filtration of a fluid, such as a liquid, includes or is composed of a support element made of a porous ceramic material, the element exhibiting a tubular or parallelepipedal shape delimited by an external surface and including, in its internal portion, a set of adjacent channels with axes parallel to one another and separated from one another by walls of the porous inorganic material, in which at least a portion of the channels and/or at least a portion of the external surface are covered with a porous separating membrane layer, wherein the separating membrane layer is made of a material essentially composed of silicon carbide (SiC), and the content by weight of elemental nitrogen of the layer constituting the porous separating membrane layer is between 0.1% and 2%.