A porous molded article having microvoids therein which comprises a stretched product of a resin molded material made up of, as the base material, an olefinic resin composition containing from 95 to 50% by weight of a crystalline olefinic resin component (A) and from 5 to 50% by weight of a polymer of a cyclic olefin having a weight average molecular weight of not less than 1,000 and less than 10,000 and a glass transition point of from 180 to 400.degree. C. component (B).
Disclosed is a stretched resin film comprising a layer (A) stretched in at least one axial direction and comprising 0 to 98 wt % of a polyolefinic resin, 2 wt % or more and less than 100 wt % of an amorphous resin and more than 0 wt % and 70 wt % or less of an inorganic finepowder and/or an organic filler. The stretched resin film of the present invention is resistant to becoming waved when offset-printed with widely-used, quick-drying offset printing inks, and thus has excellent printing properties.
Each printed sheet product includes a core of flexible, microvoided polymer sheet material and a planar RFID assembly encoded with a unique electro/magnetic code permanently and integrally joined together with the core. The microvoided sheet material collapses around the core so the sheet product remains planar. Scoring defines one or more individual identification elements removable from a remainder of the sheet product that include at least a first element with RFID assembly but only part of the core. A separate magnetic strip storing its own unique data magnetically can be provided on the first removable element even at least partially overlying the RFID assembly for independent identification operation.
Microporous material comprising a polypropylene polymer having at least 20 percent crystallinity; and a compatible, amorphous, glassy polymer, wherein said polymers are miscible in a compound when heated above the melting temperature of the polypropylene polymer and wherein a polypropylene polymer phase separates from the compound when cooled below the crystallization temperature of the polypropylene polymer. Microporous material is made by a thermally induced phase separation process using a compound such as mineral oil to form one phase containing both polymers. The pores of the microporous material resist collapse during processing. Membranes made of this material are useful as battery separators having a good combination of strength, porosity, and ionic resistance when imbibed with an electrolyte.