. "polyisobutylene" . . . "low functionality elastomers" . . . . . . . . "HaloButyl" . . . . . . . "Butyl rubber" . "butyl rubber" . "Butyl" . "Butyl rubber" . "butyl pads" . "synthetic rubber" . . "polyisobutene" . "halobutyl rubber" . "Isobutylene isoprene rubber" . . . . "butyl tapes" . "butyl" .