Removal of solid impurities from detergent lubricating oil additives - by addn. of polar solvent and phase sepn.

摘要

Mechanical impurities are removed from detergent additives for lubricating oils by phase sepn., after addn. of 0.025-10 wt.% polar liquid with dielectric constant >=17 to the additive soln. Solid particles of 0.5-5 mu m size resulting from synthesis of the additive, e.g. by neutralisation of sulphonic acid soln. in oil with Ca(OH)2. which are very difficult to separate, are reduced to below 500 mg/100 g. Prolonged centrifuging with sepn. factor 1000 and super-centrifuging: with sepn. factor 15000, are eliminated. The process causes coagulation of the particles, which increases their sedimentation rate around 1000 times.