Abstract: A heating furnace comprising a furnace body; an accommodation space in the furnace body, the accommodation space accommodating a work; an exhaust port; and a heat insulator provided between the accommodation space and the exhaust port, the heat insulator including a pillar-shaped honeycomb structure including ceramic partition walls sectioning a plurality of cells extending from one bottom to another bottom.

Abstract: A heating furnace comprising a furnace body; an accommodation space in the furnace body, the accommodation space accommodating a work; an exhaust port; and a heat insulator provided between the accommodation space and the exhaust port, the heat insulator including a pillar-shaped honeycomb structure including ceramic partition walls sectioning a plurality of cells extending from one bottom to another bottom.

Abstract: A method for manufacturing a porous honeycomb structure, which comprises a mixing and kneading step, a forming and then drying step, and a firing and then cooling step of firing a dried honeycomb article to form a fired honeycomb article and then cooling the fired honeycomb article to prepare a porous honeycomb structure, wherein the fired honeycomb article is cooled from the firing temperature under a cooling condition of a temperature falling speed of 100° C./hr or less at least in a temperature region of 800° C. or lower.

Abstract: There is provided a honeycomb structure and a method for producing the honeycomb structure, capable of reducing variance in pore diameter depending on part and capable of increasing the mean pore diameter as a whole. There is provided a method for producing a cordierite honeycomb structure 1 including the step of firing a honeycomb formed body. In the firing step, a temperature rise rate from 1200° C. to 1250° C. is controlled to 40° C./hr or more, a temperature rise rate from 1250° C. to 1300° C. is controlled to 2 to 40° C./hr, and a temperature rise rate from 1300° C. to 1400° C. is controlled to 40° C./hr or more. There is further provided a honeycomb structure having a porosity of 50 to 70%, a mean pore diameter of 15 to 30 ?m, a difference in a mean pore diameter of 5 ?m or less between in the central portion and in the outer peripheral portion, a thermal expansion coefficient of 1.0×10?6/° C.

Abstract: There is provided a honeycomb structure and a method for producing the honeycomb structure, capable of reducing variance in pore diameter depending on part and capable of increasing the mean pore diameter as a whole. There is provided a method for producing a cordierite honeycomb structure 1 including the step of firing a honeycomb formed body. In the firing step, a temperature rise rate from 1200° C. to 1250° C. is controlled to 40° C./hr or more, a temperature rise rate from 1250° C. to 1300° C. is controlled to 2 to 40° C./hr, and a temperature rise rate from 1300° C. to 1400° C. is controlled to 40° C./hr or more. There is further provided a honeycomb structure having a porosity of 50 to 70%, a mean pore diameter of 15 to 30 ?m, a difference in a mean pore diameter of 5 ?m or less between in the central portion and in the outer peripheral portion, a thermal expansion coefficient of 1.0×10?6/° C.

Abstract: A support plate for use in firing which has a main component of the crystal phase after firing being the same as that of an article to be sintered, and has a surface roughness (Ra) of the surface to be contacted with the article to be fired of 8 to 50 ?m. A firing method using the above support plate is free from the breaking or chipping of cells of a honeycomb fired article as a product and also is free from the breaking thereof during firing, the staining or cells, the cracking or deformation thereof, or the failure of reaction, which is caused by the mismatch in expansion-shrinkage behavior, and thus allows the prevention of the decrease of the yield in the production of a honeycomb fired article as a product.

Abstract: A method of producing a cordierite honeycomb structure includes: preparing clay containing a cordierite raw material having an aspect ratio of 1.5 or more; forming the clay to prepare a formed product of a honeycomb shape; drying the formed product to prepare a dried honeycomb product; and firing the dried honeycomb product to prepare a cordierite honeycomb structure. The production method can obtain a cordierite honeycomb structure capable of suppressing formation of cracks during firing.

Abstract: A method for manufacturing a porous honeycomb structure, which comprises a mixing and kneading step, a forming and then drying step, and a firing and then cooling step of firing a dried honeycomb article to form a fired honeycomb article and then cooling the fired honeycomb article to prepare a porous honeycomb structure, wherein the fired honeycomb article is cooled from the firing temperature under a cooling condition of a temperature falling speed of 100° C./hr or less at least in a temperature region of 800° C. or lower.

Abstract: There is provided a honeycomb structure and a method for producing the honeycomb structure, capable of reducing variance in pore diameter depending on part and capable of increasing the mean pore diameter as a whole. There is provided a method for producing a cordierite honeycomb structure 1 including the step of firing a honeycomb formed body. In the firing step, a temperature rise rate from 1200° C. to 1250° C. is controlled to 40° C./hr or more, a temperature rise rate from 1250° C. to 1300° C. is controlled to 2 to 40° C./hr, and a temperature rise rate from 1300° C. to 1400° C. is controlled to 40° C./hr or more. There is further provided a honeycomb structure having a porosity of 50 to 70%, a mean pore diameter of 15 to 30 ?m, a difference in a mean pore diameter of 5 ?m or less between in the central portion and in the outer peripheral portion, a thermal expansion coefficient of 1.0×10?6/° C.

Abstract: In a method for producing a honeycomb structure 20 which comprises disposing a material for forming outer wall 11 on the outer peripheral surface 3 of a cell structure 1 having a plurality of cells serving as fluid flowing channels to produce a cell structure being provided with a material for forming outer wall 10 and firing the resulting cell structure being provided with a material for forming outer wall 10, wherein a cell structure being provided with a material for forming outer wall 10 in which the absolute value of the difference between the volumetric shrinkage percentage (firing shrinkage percentage) before and after firing of the cell structure 1 and the firing shrinkage percentage of the material for forming outer wall 11 is not more than 0.5% is produced and fired.

Abstract: In a method for producing a honeycomb structure 20 which comprises disposing a material for forming outer wall 11 on the outer peripheral surface 3 of a cell structure 1 having a plurality of cells serving as fluid flowing channels to produce a cell structure being provided with a material for forming outer wall 10 and firing the resulting cell structure being provided with a material for forming outer wall 10, wherein a cell structure being provided with a material for forming outer wall 10 in which the absolute value of the difference between the volumetric shrinkage percentage (firing shrinkage percentage) before and after firing of the cell structure 1 and the firing shrinkage percentage of the material for forming outer wall 11 is not more than 0.5% is produced and fired.

Abstract: In the method for firing of ceramic honeycomb structure according to the present invention, when a formed honeycomb material having an apparent volume of 5 liters or more is fired in a firing atmosphere, the heating of the firing atmosphere from a temperature (180 to 300° C.) at which the organic binder contained in the formed honeycomb material begins to burn, to 300° C. is conducted at a temperature elevation rate of +25 (° C./hr) or more and also at such a temperature elevation rate that the difference of the temperature of the central portion of the formed honeycomb material from the temperature of the firing atmosphere is kept in a given temperature range.

Abstract: A method of producing a cordierite honeycomb structure includes: preparing clay containing a cordierite raw material having an aspect ratio of 1.5 or more; forming the clay to prepare a formed product of a honeycomb shape; drying the formed product to prepare a dried honeycomb product; and firing the dried honeycomb product to prepare a cordierite honeycomb structure. The production method can obtain a cordierite honeycomb structure capable of suppressing formation of cracks during firing.

Abstract: There is disclosed a honeycomb structure (1) comprising: porous cell partition walls (2) forming a compound material in which a plurality of cells (3) are disposed adjacent to one another; and a porous honeycomb outer wall (4) which surrounds and holds an outermost peripheral cell positioned in an outermost periphery of the cell compound material. At this time, a porosity is 5% or more and is less than 30%, and an outer peripheral distortion of the honeycomb structure (1) is 0.030 or less. According to the honeycomb structure, a method for manufacturing the structure, and a method for measuring the outer peripheral distortion of the honeycomb structure, it is possible to obtain satisfactory and practical erosion resistance and isostatic strength in the respective honeycomb structures including various cell structures.

Abstract: A composition for an optically anisotropic carbonaceous pitch suitable for the production of a carbon material having a high tensile strength and a high modulus of elasticity. The composition comprises about 2 to 20 percent by weight of a first, n-heptane-soluble component, about 15 to 45 percent by weight of an n-heptane-insoluble and benzene-soluble, second component and the balance of the composition including benzene-insoluble components. The composition has a volume ratio of an optically anisotropic phase of at least about 90% and a softening point of up to about 320.degree. C.

Abstract: A homogeneous, optically anisotropic pitch used for the production of carbon materials is prepared from a starting oil comprising a substantially chloroform-insoluble matter-free oily or tarry substance. The starting oil is subjected to thermal cracking and polycondensation to form approximately 20-80% of optically anisotropic phase pitch.