Patent ID: 7517611

Claim:
An alkaline dry battery comprising: a battery case with an opening for housing power generating elements including an alkaline electrolyte; and a seal unit for closing the opening of the battery case, wherein the seal unit includes: a negative electrode terminal plate; a negative electrode current collector having a columnar body and electrically connected to the negative electrode terminal plate; and a resin seal member, the resin seal member includes: a central cylindrical part having an opening through which the body of the negative electrode current collector is inserted; an outer peripheral cylindrical part interposed between a peripheral edge of the negative electrode terminal plate and an open edge of the battery case; a connecting part connecting the central cylindrical part and the outer peripheral cylindrical part; and a thinned section formed in the connecting part and configured to break due to gas pressure, the seal unit is attached to the opening of the battery case to seal the opening of the battery case by bending the open edge of the battery case over an upper edge of the outer peripheral cylindrical part of the seal member and crimping it inward to compress the peripheral edge of the negative electrode terminal plate, and the negative electrode current collector and the resin seal member satisfy the following formulas 1 and 2: 1.02 ≦Rc/Rb≦ 1.08 (1) 7.7≦3.14 ×Rc×L≦f ( Rc/Rb ) (2) where Rc represents the diameter (mm) of the body of the negative electrode current collector, Rb represents the diameter (mm) of the opening of the central cylindrical part of the resin seal member, L represents the length (mm) of the opening of the central cylindrical part of the resin seal member, and f ( Rc/Rb ): f ( Rc/Rb )=2048.4( Rc/Rb ) 2 −4473( Rc/Rb )+2456.9.