Abstract: Absorbent hygiene products comprising a core of an absorbent material and a top sheet through which fluid to be absorbed passes for absorption by the absorbent material are disclosed. The top sheet is porous and comprises a sheet having surfaces of a hydrophobic polymeric material modified by a graft copolymerization reaction between those surfaces and a vinyl monomer having a group capable of exhibiting hydrophilic properties. The graft polymerization reaction comprising exposure of the sheet to ultraviolet radiation while impregnated with a solution of the vinyl monomer. The grafted vinyl monomer comprises a substantially uniform coating of the sheet surface and having a mean thickness not more than about 3.0 ?m. Methods for producing this absorbent hygiene product are also disclosed.

Abstract: Non-woven fabrics are disclosed comprising substantially unbonded fibers and vinyl monomers which are capable of reacting with an acid or a base to form a salt directly or indirectly by a reaction involving exposure to ultraviolet radiation while impregnated with a solution of the vinyl monomer copolymerized to the surface of the fibers. Laminates of these non-woven fabrics as well as electrochemical devices employing them as a separator, and methods of treating such non-woven fabrics are also disclosed.

Abstract: Methods of making gel materials are disclosed including mixing a water soluble crosslinkable matrix polymer, a particulate polymer material which has been crosslinked to a gel content of at least 55% and an aqueous solvent, and crosslinking the matrix polymer to form a gel matrix of the matrix polymer in which the particles of particulate polymer material are dispersed, each of the crosslinked matrix polymer and the crosslinked particulate polymer material being capable of absorbing water. Gel materials are also disclosed including particles of a particulate polymer material capable of absorbing water and which is crosslinked so that it has a gel content of at least about 55% dispersed in a matrix of a polymer which has been crosslinked to reduce its solubility in water so that it swells rather than dissolves in water, the size of at least 60% by weight of the particles of particulate polymer material being less than about 100 &mgr;m.

Abstract: A polymeric sheet, which is particularly suited for use as a separator in an electrochemical device, is formed by graft copolymerising acrylic acid, or another vinyl monomer capable of reacting with an acid or a base to form a salt directly or indirectly with fibers of a non-woven sheet, whose outer surface is provided by a polyolefin, especially polypropylene. The polyolefin is crosslinked as a result of the polymerisation reaction. The polymerisation reaction is preferably initiated by exposure of the sheet to ultraviolet radiation, after impregnation with an appropriate solution of the vinyl monomer.

Abstract: This invention relates to a gel wound dressing material, and to techniques for preparing and using such a material. The invention provides a gel wound dressing in which the polymer component comprises a copolymer of a starch and a monounsaturated carboxylic acid or an ester or salt thereof, the copolymer being in the form of particles of which at least 70% by weight have a size of not more than about 100 um; and water. 1.

Abstract: A polymeric sheet, which is particularly suited for use as a separator in an electrochemical device, is formed by graft copolymerizing acrylic acid, or another vinyl monomer capable of reacting with an acid or a base to form a salt directly or indirectly with fibers of a non-woven sheet, whose outer surface is provided by a polyolefin, especially polypropylene. The polyolefin is crosslinked as a result of the polymerization reaction. The polymerization reaction is preferably initiated by exposure of the sheet to ultraviolet radiation, after impregnation with an appropriate solution of the vinyl monomer.

Abstract: A filter consisting of a filter tube of a porous polymeric material having tendency to collapse towards a predetermined flattened configuration and a porous support sleeve disposed around the filter tube, so as to support the filter tube against internal fluid pressure, while providing no more resistance to flow of fluid than the filter tube.

Abstract: A composite membrane comprises a first material which defines a porous matrix and a second material blocking the pores of the matrix, the second material having been crosslinked by irradiation, preferably with UV radiation, when in the pores. Preferably a crosslinking agent is mixed with the second material.The porous matrix may be made by leaching a water soluble material from a blend of that material with polyethylene. The second material may be polymerizable, for example an acrylic acid derivative.

Abstract: A microporous polymeric film of high porosity comprises a halopolymer in which the repeating units are --(C.sub.n H.sub.2n)-- and --(C.sub.m X.sub.2m)-- in which each X independently represents fluorine or chlorine and the values of n and m are greater than one and less than six. The film is the result of firstly melt processing a mixture of the halopolymer, more than 150 parts by weight of an extractable salt and not more than 80 parts by weight of an extractable polymer per 100 parts by weight of the halopolymer, the extractable polymer not being completely and homogeneously mixed with the halopolymer and being less viscous than the halopolymer when both are molten so that the surfaces of the film resulting from melt processing are rich in the extractible polymer, and secondly extracting at least some of the extractable salt to render the film porous and extracting at least some of said polymer to impart surface porosity to the film.

Abstract: Melt-extruded polymeric electrolyte material for electrochemical power cells may be coextruded with other components of the cell, notably a lithium metal anode.

Abstract: A method of making a plugged microporous film from a film which comprises a structural component having pores extending therethrough, and a plugging material within the pores, the method comprising:(a) selectively treating the plugging material so that its susceptibility to a crosslinking treatment differs from a first region of the film to a second region thereof;(b) crosslinking the plugging material at the second region of the film; and(c) removing the uncrosslinked plugging material from the first region of the film leaving plugs of crosslinked plugging material in the pores at the second region of the film.

Abstract: Sensitive electrode material, e.g. lithium electrode material, protected by a flexible layer of material which is swellable by liquid with which it will come into contact in use, and can thus, for example, act as an electrode separator when assembled in an electrical cell containing such a liquid. The protected electrode material can be processed, e.g. rolled into thin sheets, and can conveniently be fed to automatic cell assembly apparatus.

Abstract: Sensitive material, e.g. lithium electrode material, is provided with a protective layer of fluid-impermeable material, which is subsequantly rendered permeable by altering its physical structure, e.g. by perforation, without altering its composition. The permeable material can act, for example, as an electrode separator when the resulting article is assembled into an electrolytic cell, and the protected material can be processed, e.g. rolled into thin sheets, and conveniently fed to automatic assembly apparatus.

Abstract: A polymeric component, for use as a separator in an electrochemical device in which the anode comprises metallic lithium, comprises a thermoplastic polymer, a tertiary plasticizer and a filler that comprises a lithium compound which is substantially insoluble in both the polymer and the plasticizer. The component is rendered porous by deformation which increases its surface area. The porosity can be enhanced by extracting one or both of the plasticizer and the filler.

Abstract: An article which is rendered waterproof by a microporous membrane of a hydrophobic material, the pores of the membrane in a layer-like region on or towards a surface thereof being plugged with a hydrophilic material, leaving hydrophobic material exposed on the said surface between the pores.