The disclosure provides for a mixture suitable for extrusion and firing to form a ceramic honeycomb substrate, said mixture comprising a batch composition selected from the group consisting of a cordierite batch composition and an aluminum titanate batch composition, an optional pore former material; a binder material and water; wherein said binder is a methyl ether of cellulose binder having a count of less than 300 water-insoluble fibers per gram of binder material.

The honeycomb structure body has a dense part at a part in axial direction including a center region of the inflow end face, the dense part having a change ratio of porosity calculated by the following Expression (1) that is 2 to 8%, and has an outside-diameter increasing part, and the honeycomb structure body has a change ratio of average diameter calculated by the following Expression (2) that is 0.2 to 3%,

(1−Px/Py)×100, Expression (1): in Expression (1), Px denotes the porosity (%) at the center region of the inflow end face, and Py denotes the porosity (%) of a circumferential region of the inflow end face.

(1−Dx/Dy)×100,   Expression (2): in Expression (2), Dx denotes the average diameter (mm) of the inflow end face, and Dy denotes the average diameter (mm) of the outflow end face.

The honeycomb structure body has a dense part at a part in axial direction including a center region of the inflow end face, the dense part having a change ratio of porosity calculated by the following Expression (1) that is 2 to 8%, and has an outside-diameter increasing part, and the honeycomb structure body has a change ratio of average diameter calculated by the following Expression (2) that is 0.2 to 3%,

(1−Px/Py)×100, Expression (1): in Expression (1), Px denotes the porosity (%) at the center region of the inflow end face, and Py denotes the porosity (%) of a circumferential region of the inflow end face.

(1−Dx/Dy)×100,   Expression (2): in Expression (2), Dx denotes the average diameter (mm) of the inflow end face, and Dy denotes the average diameter (mm) of the outflow end face.

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.

Disclosed is a honeycomb support structure comprising a honeycomb body and an outer layer or skin formed of a cement that includes an inorganic filler material having a first coefficient of thermal expansion from 25° C. to 600° C. and a crystalline inorganic fibrous material having a second coefficient of thermal expansion from 25° C. to 600° C.

A ceramic honeycomb body, suitable for use in exhaust gas processing, includes a honeycomb structure having a plurality of through-channels, a first portion of the plurality of through-channels have a first hydraulic diameter dh1, a second portion of the plurality of through-channels have a second hydraulic diameter that is smaller than the first hydraulic diameter dh1, the first hydraulic diameter dh1 is equal to or greater than 1.1 mm, and the first and second portions of through-channels, taken together, have a geometric surface area GSA greater than 2.9 mm.sup.−1. Diesel oxidation catalysts and methods of soot removal are also provided, as are other aspects.

A honeycomb structure includes a honeycomb segment bonded member including; a plurality of prismatic columnar shaped honeycomb segments; and a bonding layer bonding the segments, wherein one honeycomb segment has a bulge on one side face, extending in an axial direction, another honeycomb segment has a recess on one side face, extending in the axial direction, the one honeycomb segment and the another are disposed adjacent and bonded to each other via the bonding layer with the bulge inserted in the recess, length of the bulge is smaller than length of the one side face of the one honeycomb segment, length of the recess is smaller than length of the one side face of the another honeycomb segment, a base part of the bulge is defined with a bent side face, an angle between an imaginary bottom face and the bent side face of the bulge being 60° or more.

A honeycomb structure includes a honeycomb segment bonded member including; a plurality of prismatic columnar shaped honeycomb segments; and a bonding layer bonding the segments, wherein one honeycomb segment has a bulge on one side face, extending in an axial direction, another honeycomb segment has a recess on one side face, extending in the axial direction, the one honeycomb segment and the another are disposed adjacent and bonded to each other via the bonding layer with the bulge inserted in the recess, length of the bulge is smaller than length of the one side face of the one honeycomb segment, length of the recess is smaller than length of the one side face of the another honeycomb segment, a base part of the bulge is defined with a bent side face, an angle between an imaginary bottom face and the bent side face of the bulge being 60° or more.

A honeycomb structure, including: a plurality of pillar shaped honeycomb segments, each of the pillar shaped honeycomb segments including a partition wall and a plugged portion; and a joining layer arranged so as to join side surfaces of the pillar shaped honeycomb segments to each other. The honeycomb structure satisfies the following equations (1) to (3):
y≤1000  (1);
y≤717.92x.sup.−0.095  (2); and
y≥462.4x.sup.−0.153  (3),
in which y is a maximum temperature (° C.) at which the use of the honeycomb structure is accepted, and x is a thermal conduction factor represented by the following equation:
thermal conduction factor=(thermal conductivity of the partition wall×thermal conductivity of the joining layer)/(average thickness of the joining layer×porosity of the partition wall).

A honeycomb structure, including: a plurality of pillar shaped honeycomb segments, each of the pillar shaped honeycomb segments including a partition wall and a plugged portion; and a joining layer arranged so as to join side surfaces of the pillar shaped honeycomb segments to each other. The honeycomb structure satisfies the following equations (1) to (3):
y≤1000  (1);
y≤717.92x.sup.−0.095  (2); and
y≥462.4x.sup.−0.153  (3),
in which y is a maximum temperature (° C.) at which the use of the honeycomb structure is accepted, and x is a thermal conduction factor represented by the following equation:
thermal conduction factor=(thermal conductivity of the partition wall×thermal conductivity of the joining layer)/(average thickness of the joining layer×porosity of the partition wall).