초록 ▼

The present invention is directed to microporous membranes having a surfactant impregnated therein which is coated on at least one surface thereof with a polymer coating, such as cellulose acetate. The polymer coating possesses functional groups in the presence of an aqueous alkaline environment whi

The present invention is directed to microporous membranes having a surfactant impregnated therein which is coated on at least one surface thereof with a polymer coating, such as cellulose acetate. The polymer coating possesses functional groups in the presence of an aqueous alkaline environment which permits it to undergo hydrogen bonding with water and to transport battery electrolyte through the coating by diffusion. The presence of the coating on the normally hydrophobic substrate membrane, when used in conjunction with a suitable surfactant, increases the wettability of the substrate membrane and thereby lowers its electrical resistance. The coating also serves to immobilize various soluble electrode derived ions at the coating-electrolyte interface thereby hindering their penetration into the pores of the substrate microporous membrane. Consequently, the plugging of the pores of the substrate membrane by these ions is substantially reduced thereby increasing the life of a battery in which said coated membranes are used as the battery separators.

대표청구항 ▼

A hydrophilic open-celled microporous membrane which comprises a normally hydrophobic microporous membrane, having deposited on at least one surface thereof a coating comprising a polymer selected from the group consisting of cellulose esters, and polyvinyl alcohol, said coating having a dry thickne

A hydrophilic open-celled microporous membrane which comprises a normally hydrophobic microporous membrane, having deposited on at least one surface thereof a coating comprising a polymer selected from the group consisting of cellulose esters, and polyvinyl alcohol, said coating having a dry thickness of from about 1 to about 25 microns, and a surfactant disposed within said coated microporous membrane in a manner and in at least an amount sufficient to render the substrate microporous membrane hydrophilic.