Inorganic composites used as separators

A structural material for use in the fabrication of separators for alkaline storage cells wherein evolved gases recombine to form elevated temperatures in the presence of aqueous alkaline electrolyte solutions, said materials being stable with respect to said elevated temperatures, permeable with respect to said gases and wettable by said solutions and comprising a woven fabric of fragile inorganic metallic oxide fibers which are chemically inert with respect to said alkaline solutions and are characterized by uneven porous surfaces separated by intersticies, through which said gases flow, reinforced with thermally stable crystalline high molecular weight fluoroplastic particles deposited onto said surfaces and sintered to form a discontinuous reinforcing matrix of fluoroplastic resin which adheres to said fiber surfaces.

A structural composite comprising a major portion of fragile porous inorganic fibers having irregular surfaces reinforced with a minor portion of thermally stable crystalline high molecular weight fluoroplastic particles wherein said fibers are formed into a woven fabric having a multiplicity of interstices between said fibers and said particles are absorbed to said fiber surfaces and sintered thereby providing a discontinuous fluoroplastic matrix which permanently adheres to said fibers and reinforces said fabrics while retaining essentially all of the inherent characteristics of said fibers.

An inorganic-organic thermally stable composite material that is wettable in aqueous alkaline solutions, chemically resistant to said solutions, and mechanically strong comprised of a porous, fragile, inorganic substrate of fibers selected from the group consisting of zirconium oxide-yttrium oxide mixtures, potassium titinate, and thorium oxide physically reinforced with a discontinuous coating of sintered crystalline high molecular weight fluoroplastic particles selected from the group consisting of tetrafluoroethylene, chlorotrifluoroethylene, fluorinated ethylene propylene, polyvinylidene fluoride and polyvinyl fluoride that have been absorbed onto the surface of said substrate.