| 摘要 |
PROBLEM TO BE SOLVED: To provide a varnish for manufacturing a porous polyamide imide film having high air permeability, a porous polyamide imide film, a porous separator for a battery including the porous polyamide imide film, and a secondary battery.SOLUTION: The porous polyamide imide film is formed using the varnish containing polyamide imide, silica particles and a phosphoric ester salt based surfactant. It is preferable that the phosphoric ester salt based surfactant is amine salt of one or more acidic phosphate esters selected from among polyoxyalkylene alkylether phosphate, polyoxyalkylene alkylphenylether phosphate and alkyl phosphoric acid.SELECTED DRAWING: None |
