Improved N B R Vulcanizates for Use in Fuel Lines

The aging and “sour” gasoline resistance of fuel line hose tube can be improved by appropriate choice of compound to meet the requirements of recently upgraded specifications. The use of an NBR designed for heat resistant compounding, together with silica filler and selected plasticizer and antioxidant and a low sulphur sulphur-donor cure all contribute to improved performance. It is preferable to use cadmium oxide as activator but promising zinc oxide activated compounds have also been identified. It is desirable for both aging and “sour” gasoline resistance to use an NBR with acrylonitrile content as close to 40% as low temperature requirements permit.