The performance of automotive and industrial gear oils is generally enhanced by adding polybutenes due to their exceptional thickening capability and shear stability.

Certain parameters should be considered when selecting gear oil:

  • Gear design
  • Gear material
  • Conditions of operation

Health, safety and the environment are becoming key drivers to improve the workplace and reduce emissions in the manufacturing of lubricating oils and therefore polybutenes are especially well selected due to their low toxicity and very low deposit formation.

Properties

  • low pour point
  • good shear stability
  • low carbon residue
  • corrosion protection

End User Applications

Gear oils are often split into 2 different categories (End User Applications):

Automotive

Polybutenes have valuable qualities for the automotive gear oil industry. They provide excellent thickening, shear stability, cleanliness.  They are particularly suited to replace API Group I bright stock and high viscosity base oils.

The viscosity index (VI) is the rate of change of viscosity between two temperatures. The lower the VI, the greater the drop in viscosity as the oil warms up. The higher the VI, the less the drop in viscosity as the oil warms up. The flow properties change at different temperatures and conditions, for example: during a cold start, the greatest strain occurs due to the heavy drag from the syrup-like oil. At first the oil’s viscosity will thin out rapidly, however as soon as the engine warms up the viscosity will stabilise as a running temperature is reached.

Polybut™ 150, 200, 600 fit very well but also the lower viscous PIBs can be used, depending on the requirements for the gear.

PAO mixed with the PIB will increase the price of the formulation but will also improve the viscosity index.

Properties

  • good shear stability
  • viscosity index improver in the formulation of high quality multigrade oils
  • efficient oil thickness at high temperature
  • improve pour point of the formulation
  • anti-wear protection

End User Applications

  • manual transmission fluid to adjust drive shaft torque and speed
  • differential fluid to increase and split drive shaft torque to the axles, while allowing different wheel speeds
  • transfer case fluid to adjust and split 4WD torque to front and rear drive shafts while allowing different shaft speeds

Industrial

The advantages of using PIB in industrial gear oils are many: they can replace bright stocks, mineral oils and other thickeners; they burn cleanly, leaving no residue at elevated temperatures.

To maximise the energy efficiency of the gear oils, the polybutene needs to have:

  • high shear
  • high VI, good low temperature properties
  • good adhesion so low misting during production and increase retention time of the oil

There are gear oils for open and closed systems:

  • Open system gear oils: are used in industrial open gears at high temperatures in open gearing for mining, ore processing.
  • Closed system gear oils: are used in extreme conditions to splash, spray and/or mist within the oil system, for example roller bearings, elastic clutches.

Properties

  • outstanding load carrying
  • outstanding wear protection
  • oxidation resistance
  • rust and corrosion protection
  • anti-foam
  • friction reduction

End User Applications

  • industrial gears and bearings
  • ball, roller and anti-friction bearings
  • where low ambient temperatures require extra fluidity
  • heavily loaded gear sets