METHOD FOR IMPROVING POLYPROPYLENE-BASED BASE MATERIAL

摘要

PURPOSE:To produce the subject base having excellent hydrophilic nature, alkali resistance and acid resistance, by irradiating woven fabric or nonwoven fabric made of a polypropylene copolymer with electron rags and graft- copolymerizing a hydrophilic monomer onto the copolymer. CONSTITUTION:Nonwoven fabric produced by using a propylene.ethylene.random copolymer containing 0.1-1.5wt.% ethylene content by a melt blow method is irradiated with ionizing radiation (5-500KGY as irradiation dose) to make the nonwoven fabric hydrophilic and (meth)acrylic acid is subjected to graft copolymerization onto the copolymer so that the nonwoven fabric is provided with hydrophilic nature while suppressing reduction in mechanical strength of the nonwoven fabric to the minimum to give the objective modified polypropylene-based resin having excellent hydrophilic nature (water retention characteristics) and excellent handle. The nonwoven fabric is useful as a separator for a cell using an aqueous electrolyte.