| abstract |
The present invention includes an elastomeric composition of a halogenated rubber component, a filler such as carbon black, and polybutene processing oil, the processing oil having a number average molecular weight of least 40 0 in one embodiment, and less than 10,000 in another embodiment. The rubber component can be a halogenated butyl rubber or a halogenated star-branched butyl rubber. In one embodiment, the polybutene processing oil is present in the composition from 2 to 30 phr, while the halogenated rubber component is present in the composition from 50 to 100 phr in one embodiment, and the filler is present from 10 to 150 phr in one embodiment. Further, a secondary rubber component may be present such as natural rubber. The compositions of the invention have an air permeability of from 1 x 10-8 to 3 x 10-8 cm3-cm/c m2- sec-atm at 65~C, and are useful for air barriers such as an innerliner for a tire. |