| 摘要 |
A separator for a nonaqueous electrolyte secondary battery that at least includes a resin (A) having a crosslinked structure, which is obtained by irradiating with an energy ray an oligomer polymerizable by irradiation with an energy ray. The separator has an average pore size of 0.005 to 0.5 mum, an air permeability of 50 sec/100 mL or more and less than 500 sec/100 mL, where the air permeability is expressed as a Gurley value, and a thermal shrinkage of less than 2% at 175° C. The separator for a nonaqueous secondary battery can be produced by the production method of the present invention, which includes the steps of: applying to a substrate a separator forming composition containing the oligomer, two or more kinds of solvents having different polarity from each other, and the like; irradiating the applied composition with an energy ray; and drying the energy ray-irradiated composition. |
