A closure assembly for filling a container under isolated conditions. The closure assembly includes a collar with internal threads for coupling with a finish of the container. A disc includes first coupling members for removably coupling with the collar. A liner is secured to the disc. The liner is seated on the finish of the container when the collar is coupled to the finish.

The invention relates to a container closure (1, 21, 41, 61) with a sealing element (3, 23, 43, 63). The sealing element (3, 23, 43, 63) comprises a polymer composition. The polymer composition comprises a butene copolymer. The butene copolymer has a melting temperature Tm of between 30 C. and 130 C., wherein the melting temperature Tm is determined by the second heating curve of a DSC measurement at a heating rate of 10 C. min-1.

The invention relates to a container closure (1, 21, 41, 61) with a sealing element (3, 23, 43, 63). The sealing element (3, 23, 43, 63) comprises a polymer composition. The polymer composition comprises a butene copolymer. The butene copolymer has a melting temperature Tm of between 30 C. and 130 C., wherein the melting temperature Tm is determined by the second heating curve of a DSC measurement at a heating rate of 10 C. min.sup.1.

A vessel closure (1, 21, 41, 61) includes a sealing element (3, 23, 43, 63). The sealing element (3, 23, 43, 63) includes a polymer composition. The polymer composition includes a polyalphaolefin with kinematic viscosity, determined according to ASTM D445/ISO 3104, of at least 4 cSt, at a temperature of 100 C., and/or a dropping point, determined according to ASTM 5950, of at most 10 C., and up to 95% by weight of a second polyolefin.