Patent ID: 8404327

Claim:
A honeycomb structure comprising: a periphery-ground article obtained by grinding an outer peripheral portion of a cell structure where a plurality of honeycomb segments are bonded by means of a bonding layer at an outer wall of each of them, and an outer peripheral coat layer disposed on an outer peripheral face of the periphery-ground article; wherein at least one of the bonding layer and the outer peripheral coat layer is formed by the use of honeycomb-forming slurry containing (1) biologically soluble fibers containing a metal oxide capable of extricating a metal ion and (2) an inorganic binder containing a colloidal oxide having modified silica sol, the modified silica sol being manufactured by adding a substance containing amine or an aqueous solution of a water-soluble metalate of an amphoteric metal to silica sol, wherein each biologically soluble fiber has an alkali metal oxide content that is greater than 0 and less than or equal to 2% by mass of the biologically soluble fiber, wherein the inorganic binder has a pH value of 4 to 11 at 25° C. and wherein a silica solid content of the modified silica sol has an average particle diameter of 10 to 80 nm.