Alkaline dry battery and sealing gasket therefor

An alkaline dry battery comprising:

• an alkaline power generation element including a cathode mixture formed into a tubular shape, a separator disposed inside the cathode mixture, the separator being impregnated with an alkaline electrolyte, and a gelled anode mixture filled in the inside of the separator;
• a cylindrical metallic battery case with a closed bottom that contains the alkaline power generation element and serves as both a cathode terminal and a cathode current collector;
• a dish-shaped metallic anode terminal plate having a bar-shaped anode current collector fixed vertically thereon in an internal surface thereof, the anode current collector being inserted into the anode mixture of the power generation element;
• and
• a sealing gasket of a polyamide resin disposed between the battery case and the anode terminal plate without using a stiffening member to seal the battery case in an airtight manner;
• wherein the sealing gasket formed as an integrated molding product includes
• a central boss through which the anode current collector is inserted,
• a perimeter part which is disposed between an opening of the battery case and a peripheral part of the anode terminal plate and forms an airtight sealing by stress deformation caused by flexing the opening of the battery case inwardly,
• a middle barrier positioned between the boss and the perimeter part,
• a safety valve configured by a first thin wall part provided in a circular part between the boss and the middle barrier, and
• a stress absorbing part configured by a second thin wall part formed by bending the circular part between the perimeter part and the barrier, and
• wherein the sealing gasket is made of a polyamide resin of polyhexamethylene dodecanamide.