Abstract: An improved battery separator for lead-acid battery cells has low resistance to electrolyte ion transfer and can assist in holding paste in contact with a grid of an electrode plate during chemical reactions of the cell. The separator is formed by depositing an improved wetting composition to a polyolefin substrate comprised of entangled microfibers. The wetting composition which is deposited over and adhered to external surfaces of the microfibers is comprised of a substantially homogeneous admixture of an epoxy emulsion and a polyfunctional amine curing agent. When the separator is immersed in electrolyte, the amine groups in the cured resin of the wetting composition react with the acid electrolyte and are substantially completely neutralized forming a polymeric salt; in the process the fibers are rapidly wetted, providing a substantially permanent wetting characteristic in the electrolyte.

Abstract: An improved electrolyte absorber for alkaline battery cells has low resistance to electrolyte ion transfer and can hold alkaline electrolyte in contact with an electrode during chemical reactions of the cell. The absorber is formed by depositing an improved wetting compositions to a polyolefin substrate. The substrate, preferably, is a fibrous and porous melt blown thermoplastic web made up of a plurality of physically entangled microfibers, resistant to strong alkali and oxidation. The wetting composition which is deposited over and adhered to external surfaces of said microfibers is comprised of a substantially homogeneous admixture of a polymeric binder, inert hydrophilic filler particles and a phosphate ester wetting agent. Portions of the filler particles in the composition protrude through the binder and are exposed in random distribution. When the absorber is immersed in electrolyte, the phosphate ester wetting agent reacts with the electrolyte to lower the surface tension thereof.

Abstract: An improved battery separator for alkaline battery cells has low resistance to electrolyte ion transfer and high resistance to electrode ion transfer. The separator is formed by applying an improved coating to an electrolyte absorber. The absorber, preferably, is a flexible, fibrous, and porous substrate that is resistant to strong alkali and oxidation. The coating composition includes an admixture of a polymeric binder, a hydrolyzable polymeric ester and inert fillers. The coating composition is substantially free of reactive fillers and plasticizers commonly employed as porosity promoting agents in separator coatings. When the separator is immersed in electrolyte, the polymeric ester of the film coating reacts with the electrolyte forming a salt and an alcohol. The alcohol goes into solution with the electrolyte while the salt imbibes electrolyte into the coating composition.