METHOD OF PRODUCING MICROPOROUS POLYETHYLENE MEMBRANE AND STORAGE BATTERY SEPARATOR Russian patent published in 2011 - IPC B01D71/26 B32B27/32 C08L23/06 H01M2/14 H01M2/16 

FIELD: process engineering.

SUBSTANCE: invention relates to production of microporous polyethylene membranes to be used in storage battery separators. Membrane is produced by mixing polyethylene resin melt and membrane-forming solvent to prepare solutions of polyethylene resin A with concentration of 25-50% by wt and with that B of 10-30% by wt. Note here that concentration of A exceeds that of B. Melts are simultaneously extruded through spinneret, extrudate is cooled to produce gel-like sheet wherein resins A and B are laminated and membrane-forming solvent is removed. Solutions of resins A and B may be extruded through separate spinnerets with removal of membrane-forming solvent from obtained gel-like sheets A and B, formation of microporous polyethylene membranes A and B and their lamination in controlling mean diametre of pores over membrane depth.

EFFECT: microporous polyethylene membranes with balances mechanical properties, permeability, anti-shrinking properties, resistance to compression, absorption capacity, and pore mean diametre varying over membrane depth.

5 cl, 2 tbl, 16 ex