FIELD: chemistry.
SUBSTANCE: microporous polyolefin membrane which contains polyolefin resin and having (a) shutdown temperature of 135°C or lower, at which air permeability measured while heating at a rate of 5°C/min reaches 1×105 seconds/100 cm3, (b) maximum shrinkage coefficient during melting of 40% or less in the cross direction in temperature range of 135-145°C, which is measured through thermomechanical analysis under a load of 2 gram-force and while raising temperature at a rate of 5°C/min, and (c) melting point of 150°C or higher, at which air permeability, measured with further heating after reaching the said shutdown temperature, again becomes equal to 1×105 seconds/100 cm3.
EFFECT: design of a microporous polyolefin membrane with high stability of properties.
8 cl, 5 dwg, 1 tbl, 10 ex
