In the past political and economical developments have frequently required rapid changes in crude and consequently base oil supply.
Changing crude oil provenances means changing paraffin content and structure of base oils and subsequently to a certain degree low temperature properties. The most important problem area is represented by engine oil formulations with their stringent requirements for startability and pumpability under winter conditions.
Today most potent pour point depressants - primarily based on the flexible chemistry of polyalkylmethacrylates - are able to solve problems by optimum control of paraffin crystallization. The application for these specialised products ranges from blends of a wide variety of conventional base oils to the even more difficult special raffinates and to semi or part synthetic formulations e.g. for SAE 5W-30 oils.
The functionality of these most potent pour point depressant has been extended to provide viscosity increase and viscosity index improvement as well as dispersancy. The first effect is only limited by shear requirements or the molecular weight of the polymethacrylates. Due to their small thickening effects at -20°C or -25°C the multifunctional pour point depressants allow more flexibility in adjusting base oil blends to meet CCS viscosity or volatility targets. The second effect i.e. the dispersancy has been included to replace some of the PIB-based dispersants with its poorer CCS-thickening properties and to achieve maximum performance in sludge tests such as Sequence VE or M102E without impairing low temperature startability, often a limiting factor in formulating high performance gasoline and diesel engine oils.
The sum of properties of the new multifunctional pour point depressant is technically and economically attractive.
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