Abstract: A closure for a container is described. The container has an opening through which contents of the container are dispensed and a holding member (255, 285, 295, 305, 315, 316, 317, 340, 350) for cooperating with the closure to retain the closure on the container. A sealing member (220) is configured to sealingly close the container opening. The sealing member includes a retention member (260, 275, 290, 300, 310, 325, 335, 345, 355) engageable with the holding member of the container to retain the sealing member in sealing engagement with the container. A cap member (225) has a top rim and a sidewall depending from the top rim. The sidewall includes an attachment member (160) for attachment to the container and an engagement member (245) that operatively couples the sealing member to the cap member upon placement of the cap member on the container. The cap member is rotatable relative to the container and relative to the sealing member.

Abstract: A retortable container (C) or a retortable closure (10) for use with the container (C). A receptacle (R) is included that may incorporate fasteners (F) attaching the closure (10). The closure (10) includes a retainer (20) received with a sealing barrier (100) formed from a polymeric material. The sealing barrier (100) includes a heat transfer material such as powdered metal in a volume that is between about 25% and about 65% of the closure (10) and an an oxygen barrier material such as a nanocompound or other barrier material having a relative volume of approximately between 10% and 60%. Variations of the closure (10) may incorporate seal layer of a thermoplastic elastomeric vulcanizate such as a santoprene and the heat transfer material may be an economically attractive powdered and/or oxide material such as zinc, aluminum, copper, nanotube, or similarly available material, which preferably is diffused throughout the closure (10).