Method of producing a heat shrinkable elastomer and articles utilizing the elastomer

摘要

A heat-shrinkable elastomer having a first length is produced by uniaxially orienting a copolymer having hard block and elastomeric soft block polymer segments to a second length which is substantially greater than a third length at which partial permanent deformation occurs. Upon removal of the tensioning force, the stretched elastomer naturally relaxes to the third length which is substantially greater than the first length but less than the second length. Upon application of heat, the elastomer shrinks and recovers its elastic properties. The heat-shrinkable elastomer can be coextruded by conventional techniques as a core layer disposed between nonelastic outer layers or skins, and the resulting coextruded elastomer can be uniaxially tensioned as above. Articles or garments such as disposable diapers advantageously use the heat-shrinkable elastomer of the present invention as a means to shirr portions thereof, such as waistbands.