Abstract: Microporous sheet product and methods of making and using the same. In one embodiment, the microporous sheet product is made by a process that includes melt-extruding a sheet material using an extrusion mixture that includes a thermoplastic polymer, a superabsorbent polymer, and a compatibilizing agent. After extrusion, the compatibilizing agent may be removed from the sheet material. When the sheet product is imbibed with a polar or ion-containing liquid, the superabsorbent polymer swells, causing a reduction in the pore size of the sheet product. The exposure also causes some of the superabsorbent polymer to migrate to the exterior of the microporous sheet product. The microporous sheet product may be used, for example, as a battery separator, as a food packaging material, as a diffusion barrier in the ultrafiltration of colloidal matter, and in disposable garments.

Abstract: Microporous sheet product suitable for use as a battery separator and method of forming the same. According to one embodiment, the method involves forming an extrusion mixture of one or more thermoplastic polymers and a fluid having a high vapor pressure. Next, the mixture is extruded through a die head, cooled and shaped in a first vapor zone under an above-UEL condition to form a solid sheet material. Next, the sheet material is subjected to a two-step process in a second vapor zone under a below-LEL condition, the first step involving a first stretching/fluid vaporization at a higher temperature, the second step involving a second stretching/fluid vaporization at a lower temperature. The resultant sheet is then annealed, and the remainder of fluid is removed to form a sheet product having a thickness characterized by a structure of smaller and larger pore strata across its thickness.

Abstract: Microporous sheet product and methods of making and using the same. In one embodiment, the microporous sheet product is made by a process that includes melt-extruding a sheet material using an extrusion mixture that includes a thermoplastic polymer, a superabsorbent polymer, and a compatibilizing agent. After extrusion, the compatibilizing agent may be removed from the sheet material. When the sheet product is imbibed with a polar or ion-containing liquid, the superabsorbent polymer swells, causing a reduction in the pore size of the sheet product. The exposure also causes some of the superabsorbent polymer to migrate to the exterior of the microporous sheet product. The microporous sheet product may be used, for example, as a battery separator, as a food packaging material, as a diffusion barrier in the ultrafiltration of colloidal matter, and in disposable garments.

Abstract: Microporous sheet product and methods of making and using the same. In one embodiment, the microporous sheet product is made by a process that includes melt-extruding a sheet material using an extrusion mixture that includes a thermoplastic polymer, a superabsorbent polymer, and a compatibilizing agent. After extrusion, the compatibilizing agent may be removed from the sheet material. When the sheet product is imbibed with a polar or ion-containing liquid, the superabsorbent polymer swells, causing a reduction in the pore size of the sheet product. The exposure also causes some of the superabsorbent polymer to migrate to the exterior of the microporous sheet product. The microporous sheet product may be used, for example, as a battery separator, as a food packaging material, as a diffusion barrier in the ultrafiltration of colloidal matter, and in disposable garments.

Abstract: Microporous sheet product and methods of making and using the same. In one embodiment, the microporous sheet product is made by a process that includes melt-extruding a sheet material using an extrusion mixture that includes a thermoplastic polymer, a non-cross-linked elastomer having a molecular weight of at least 50,000 Da, and a compatibilizing agent. By way of example, the thermoplastic polymer may be a polyolefin, the non-cross-linked elastomer may be a polyisobutylene, and the compatibilizing agent may be mineral spirits. After extrusion, the sheet material may be cooled, and the sheet material may be stretched. The microporous sheet product may be used, for example, as a battery separator, as a food packaging material, as a diffusion barrier in the ultrafiltration of colloidal matter, and in disposable garments.

Abstract: Microporous sheet product and methods of making and using the same. In one embodiment, the microporous sheet product is made by a process that includes melt-extruding a sheet material using an extrusion mixture that includes a thermoplastic polymer, a non-cross-linked elastomer having a molecular weight of at least 50,000 Da, and a compatibilizing agent. By way of example, the thermoplastic polymer may be a polyolefin, the non-cross-linked elastomer may be a polyisobutylene, and the compatibilizing agent may be mineral spirits. After extrusion, the sheet material may be cooled, and the sheet material may be stretched. The microporous sheet product may be used, for example, as a battery separator, as a food packaging material, as a diffusion barrier in the ultrafiltration of colloidal matter, and in disposable garments.

Abstract: Microporous sheet product and methods of making and using the same. In one embodiment, the microporous sheet product is made by a process that includes melt-extruding a sheet material using an extrusion mixture that includes (i) a cyclic olefin copolymer, (ii) an electrolyte swellable thermoplastic, and (iii) a compatibilizing agent that promotes mixing of the cyclic olefin copolymer and the electrolyte swellable thermoplastic, the compatibilizing agent having a boiling point in the range of 135-300° C. As an example, the cyclic olefin copolymer may be an ethylene-norbornene copolymer, the electrolyte swellable thermoplastic may be polyethylene oxide, and the compatibilizing agent may be mineral spirits. After extrusion, the sheet material may be cooled, and the compatibilizing agent may be removed, forming an ionically-conductive microporous sheet product.

Abstract: Microporous sheet product and methods of making and using the same. In one embodiment, the microporous sheet product is made by a process that includes melt-extruding a sheet material using an extrusion mixture that includes (i) a cyclic olefin copolymer, (ii) an electrolyte swellable thermoplastic, and (iii) a compatibilizing agent that promotes mixing of the cyclic olefin copolymer and the electrolyte swellable thermoplastic, the compatibilizing agent having a boiling point in the range of 135-300° C. As an example, the cyclic olefin copolymer may be an ethylene-norbornene copolymer, the electrolyte swellable thermoplastic may be polyethylene oxide, and the compatibilizing agent may be mineral spirits. After extrusion, the sheet material may be cooled, and the compatibilizing agent may be removed, forming an ionically-conductive microporous sheet product.

Abstract: Microporous sheet product and methods of making and using the same. In one embodiment, the microporous sheet product is made by a process that includes melt-extruding a sheet material using an extrusion mixture that includes a thermoplastic polymer, a superabsorbent polymer, and a compatibilizing agent. After extrusion, the compatibilizing agent may be removed from the sheet material. When the sheet product is imbibed with a polar or ion-containing liquid, the superabsorbent polymer swells, causing a reduction in the pore size of the sheet product. The exposure also causes some of the superabsorbent polymer to migrate to the exterior of the microporous sheet product. The microporous sheet product may be used, for example, as a battery separator, as a food packaging material, as a diffusion barrier in the ultrafiltration of colloidal matter, and in disposable garments.

Abstract: Microporous sheet product and methods of making and using the same. In one embodiment, the microporous sheet product is made by a process that includes melt-extruding a sheet material using an extrusion mixture that includes a thermoplastic polymer, a non-cross-linked elastomer having a molecular weight of at least 50,000 Da, and a compatibilizing agent. By way of example, the thermoplastic polymer may be a polyolefin, the non-cross-linked elastomer may be a polyisobutylene, and the compatibilizing agent may be mineral spirits. After extrusion, the sheet material may be cooled, and the sheet material may be stretched. The microporous sheet product may be used, for example, as a battery separator, as a food packaging material, as a diffusion barrier in the ultrafiltration of colloidal matter, and in disposable garments.

Abstract: The present invention is directed to a sheet product and to a method of forming the sheet product suitable for use as a battery separator. The method comprises forming a mixture of a thermoplastic polymer and fluid having a high vapor pressure, shaping the mixture into a sheet material and subjecting the sheet material to stretching/fluid vaporization at high temperature to form an intermediate material having a ratio of percent fluid to percent polymer crystallinity of between 0.15 and 1 followed by a second stretching/fluid vaporization at a lower temperature while removing a portion of the remainder of the fluid from the sheet. The resultant sheet is annealed and remainder of fluid removed to form a sheet product having a thickness comprising a stratified structure of small and larger pore layered configuration across its thickness.

Abstract: The present invention is directed to a sheet product and to a method of forming the sheet product suitable for use as a battery separator. The method comprises forming a mixture of a thermoplastic polymer and fluid having a high vapor pressure, shaping the mixture into a sheet material and subjecting the sheet material to stretching/fluid vaporization at high temperature to form an intermediate material having a ratio of percent fluid to percent polymer crystallinity of between 0.15 and 1 followed by a second stretching/fluid vaporization at a lower temperature while removing a portion of the remainder of the fluid from the sheet. The resultant sheet is annealed and remainder of fluid removed to form a sheet product having a thickness comprising a stratified structure of small and larger pore layered configuration across its thickness.

Abstract: The present invention is directed to a sheet product useful as a battery separator. The sheet product is composed of a microporous polymeric sheet product having at least one ply, wherein at least one ply comprises a microporous sheet formed from a polymeric composition of a first polymer having low glass transition temperature and having a second ply coating a major portion of the pore and external surfaces of the first polymer microporous sheet. The first polymer is selected from a thermoplastic polymer that has a glass transition temperature of less than ?50° C. and a melt temperature of at least 70° C. The second polymer coating a major portion of the microporous sheet of first polymer is selected from (a) a thermoplastic polymer having a glass transition temperature which is at least 60° C. above that of the first polymer or (b) a thermoset polymer having a degradation temperature that is at least 40° C.