Patent ID: 7914728
Filing Date: 2011-03-29
Classification: B01D,C04B,Y10T

Abstract:
1. A method for producing a porous honeycomb structural body with an apparent volume of at least 10 liters and at most 75 liters, the apparent volume being a volume including a space that cells of the porous honeycomb structural body occupy, the method comprising: mixing and kneading steps to obtain a green body by mixing and kneading a green body starting material containing aggregate material particles together with a dispersion medium, shaping and drying steps to obtain a dried honeycomb body by shaping the green body to obtain a shaped honeycomb green body having a plurality of cells being divided and formed by partition walls and then by drying the resultant shaped honeycomb body, and firing and cooling steps to obtain a porous honeycomb structural body by firing the dried honeycomb body to obtain a fired honeycomb body and cooling the fired honeycomb body, wherein the fired honeycomb body is cooled under a cooling atmosphere of 200° C./hour or less temperature reducing speed in a temperature range of from the firing temperature to 800° C., and 100° C./hour or less temperature reducing speed in a temperature range of less than 800° C., the fired honeycomb body being cooled under conditions in which a temperature difference between a central portion of the fired honeycomb body and an atmospheric temperature of the cooling atmosphere is kept at less than 250° C., thereby substantially preventing a formation of fine cracks in the fired honeycomb body during the cooling step and after a cordierite material is formed by firing, and wherein cordierite (2MgO.2Al