Battery separator, process for producing the same, and alkaline battery

An alkaline battery comprising:

• a sheet-like positive electrode;
• a sheet-like negative electrode;
• and
• a separator interposed between said positive electrode and said negative electrode, said separator containing a sulfonated fiber obtained by sulfonating a polyolefin resin fiber having an intrinsic viscosity number of 0.2 to 1.0 dl/gram.

An alkaline battery comprising:

• a sheet-like positive electrode;
• a sheet-like negative electrode;
• and
• a separator interposed between said positive electrode and said negative electrode, said separator containing a sulfonated fiber, said sulfonated fiber being obtained by sulfonating a polyolefin resin fiber and having a specific surface area of 0.5 m2/gram or more as determined according to the Brunauer-Emmett-Teller equation.

An alkaline battery comprising:

• a sheet-like positive electrode;
• a sheet-like negative electrode;
• and
• a separator interposed between said positive electrode and said negative electrode, said separator including a polyolefin resin fiber and having an ammonia trapping rate of 80% or more, and said polyolefin resin fiber having sulfonic groups introduced substantially uniformly on the surface of the fiber.

An alkaline battery comprising:

• a sheet-like positive electrode;
• a sheet-like negative electrode;
• and
• a separator interposed between said positive electrode and said negative electrode, said separator comprising a polyolefin resin fiber and having an ammonia trapping rate of 80% or more, said polyolefin fiber being obtained by oxidizing a surface of a polyolefin fiber and sulfonating said oxidized fiber and having sulfonic groups substantially uniformly on the surface of the fiber.