Abstract: A heater element with a functional material-containing layer includes: a honeycomb structure including an outer peripheral wall and partition walls disposed on an inner side of the outer peripheral wall, the partition walls defining a plurality of cells, each of the cells extending from a first end face to a second end face to form a flow path, at least the partition walls being made of a material having a PTC property; a pair of electrodes provided on the first end face and the second end face of the honeycomb structure; and a functional material-containing layer provided on a surface of the partition walls.

Abstract: A ceramic body is heated to a predetermined temperature by using a furnace, and a cooling gas is ejected toward a first end face of the ceramic body so that the first end face of the ceramic body is cooled. At this time, the temperature of the first end face of the ceramic body is measured by a radiation thermometer provided on the same side from which the cooling gas is ejected, and the internal temperature is measured by a thermocouple provided in the ceramic body. Thereafter, a thermal shock resistance test in which actual use conditions are simulated is performed by obtaining the temperature gradient of the ceramic body from measurement results of the temperature of the first end face of the ceramic body and the internal temperature and checking the absence or presence of cracks that occurs to the ceramic body.

Abstract: A honeycomb structure includes a honeycomb structure part having porous partition walls which form a plurality of cells having a hexagonal cross-sectional shape and extending through the honeycomb structure part from an inflow end surface to an outflow end surface to become through channels of a fluid, and having an outer peripheral wall which is positioned at an outermost periphery. A porosity of the partition walls is from 35 to 60%, an average pore diameter of the partition walls is from 1 to 5 ?m, and among the cells, incomplete cells which are the cells formed by the partition walls and the outer peripheral wall are plugged from the inflow end surface to the outflow end surface.

Abstract: There is provided a honeycomb structure 100 comprising partition walls 1 separating and forming a plurality of cells 2 functioning as fluid passages. The partition walls 1 are made of cordierite, and, when an average pore size of the partition walls 1 is x (?m) while a porosity of the partition walls 1 is y (%), a relation of x and y is y??8.33x+86.66 and satisfies 0.5?x?5 and 35?y?70. The honeycomb structure 100 can improve thermal shock resistance without sacrificing any of light-off performance, catalyst coatability, and strength.

Abstract: A ceramic body is heated to a predetermined temperature by using a furnace, and a cooling gas is ejected toward a first end face of the ceramic body so that the first end face of the ceramic body is cooled. At this time, the temperature of the first end face of the ceramic body is measured by a radiation thermometer provided on the same side from which the cooling gas is ejected, and the internal temperature is measured by a thermocouple provided in the ceramic body. Thereafter, a thermal shock resistance test in which actual use conditions are simulated is performed by obtaining the temperature gradient of the ceramic body from measurement results of the temperature of the first end face of the ceramic body and the internal temperature and checking the absence or presence of cracks that occurs to the ceramic body.

Abstract: There is provided a honeycomb structure 100 comprising partition walls 1 separating and forming a plurality of cells 2 functioning as fluid passages. The partition walls 1 are made of cordierite, and, when an average pore size of the partition walls 1 is x (?m) while a porosity of the partition walls 1 is y (%), a relation of x and y is y??8.33x+86.66 and satisfies 0.5?x?5 and 35?y?70. The honeycomb structure 100 can improve thermal shock resistance without sacrificing any of light-off performance, catalyst coatability, and strength.