| abstract |
PROBLEM TO BE SOLVED: To provide a microporous film capable of stably forming a film at a high speed and having excellent air permeability and a method for producing the same. SOLUTION: The composition comprises 30 to 50% by weight of a polyethylene resin composition comprising an ethylene-α-olefin copolymer and low density polyethylene having an ethylene component of 90 to 99% by weight, and 50 to 70% by weight of an inorganic filler. A microporous film obtained by uniaxially or biaxially stretching a resin film made of the filled filler-containing resin composition, and the resin elution amount of the polyethylene resin composition eluted by the cross separation method is 40 ° C. or more. When the temperature is less than 60 ° C, the content is 15 to 25% by weight of the total polyethylene resin composition. 5% by weight, at 80 ° C. or higher and lower than 100 ° C., 20-35% by weight of the total polyethylene resin composition, and the melt tension of the filler-containing resin composition is 18-35%. A microporous film having a thickness of 50 mN and a method for producing the same. |