Honeycomb structure and method for producing the same

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 μm, a difference in a mean pore diameter of 5 μm or less between in the central portion and in the outer peripheral portion, a thermal expansion coefficient of 1.0×10 −6 /° C. or less in each of the central portion and the outer peripheral portion, and an A-axis compression strength of 1.5 MPa or more in each of the central portion and the outer peripheral portion.

1 . A honeycomb structure made of cordierite and having a central portion and an outer peripheral portion, the honeycomb structure having:
 a porosity of 50 to 70%,   a mean pore diameter of  15  to  30  μm,   a difference in a mean pore diameter of 5 μm or less between in the central portion and in the outer peripheral portion,   a thermal expansion coefficient of 1.0×10−6/° C. or less in each of the central portion and the outer peripheral portion, and   an A-axis compression strength of 1.5 MPa or more in each of the central portion and the outer peripheral portion.   
   
   
       2 . A honeycomb structure according to  claim 1 , which has an isostatic strength of 1.0 MPa or more. 
   
   
       3 . (canceled) 
   
   
       4 . A honeycomb structure according to  claim 1 , which has a diameter of 100 mm or more and a length of 100 mm or more. 
   
   
       5 - 7 . (canceled)