Abstract: The effects of base oil type, feeding sequence, reaction temperature and reaction time in the conversion stage on the properties of the prepared grease were investigated by single factor experiment, to optimize the preparation process of calcium sulfonate complex grease with high base number. The results showed that when base oil A was used as the base oil of grease, high alkaline calcium sulfonate and fatty acid D were added in the conversion stage, under the conditions of a conversion temperature of 85 ℃ and a reaction time of 2.5 h, the performance of the high alkaline complex calcium sulfonate grease was the best, and its dropping point exceeded 343 ℃, which was higher than the dropping point height limit of GB/T 3498—2008 standard. The working cone penetration (0.1 mm) was 279, and the oil separation rate of steel mesh was 2.17%. The extreme pressure and anti-wear performance is excellent, and many properties are better than those of similar greases on the market.

Key words: high alkaline calcium sulfonate, calcium sulfonate complex grease, drop point, working cone penetration