Nitrile butadiene rubber, referred to as NBR, is mainly produced by low-temperature emulsion polymerization, from butadiene and acrylonitrile copolymerization and made of a synthetic rubber, its oil resistance is good, so oil resistance requirements of the O ring generally used nitrile rubber, its wear resistance is higher, heat resistance is better, strong adhesion. Its disadvantages are low temperature resistance, ozone resistance, poor insulation, low elasticity.

The content of acrylonitrile in NBR (%) includes 42 ~ 46, 36 ~ 41, 31 ~ 35, 25 ~ 30, 18 ~ 24 and so on. The more acrylonitrile content, the better oil resistance, but the corresponding decrease in cold resistance. It can be used in 120℃ air or 150℃ oil for long time. In addition, it also has good water resistance, air tightness and excellent bonding properties. It is widely used in making all kinds of oil-resistant o-rings, gaskets, gaskets, sleeves, soft packaging, soft rubber pipes, printing and dyeing rollers, cable rubber materials, etc., and it has become an essential elastic material in the industries of automobile, aviation, petroleum and photocopying.

The common density of nitrile butadiene rubber o-ring is mainly 55-75, and generally 65 hardness is more common, which is mainly determined by the required compactness, stress and vibration of nitrile rubber seal.