| abstract |
Disclosed is a film having a property that an electrolytic solution can easily permeate and permeate, has reduced heat shrinkage, has excellent handleability, and is visible in the electrolytic solution, and a method for producing the film. A film comprising the following step (1A), step (2A), step (3) and step (4), or comprising step (1B), step (3) and step (4) Manufacturing method. Step (1A): a step of bringing the stretched polytetrafluoroethylene film into contact with a solution containing inorganic powder, Step (2A): a step of bringing the film obtained in Step (1A) into contact with a solution containing a resin having a hydrophilic group, Step (1B): a step of bringing a stretched polytetrafluoroethylene film into contact with a solution containing an inorganic powder and a resin having a hydrophilic group, Step (3): a step of attaching a silane coupling agent to the film obtained in the step (2A) or the step (1B), Step (4): A step of heating and drying the film obtained in the step (3) at 50 to 200 ° C. [Selection figure] None |