3024. ----- [RUHRCHEMIE, A. G.] [Process for Improving Lubricating Oils.] German Patent Appl. --, R 432, filed Feb. 11, 1939. TOM Reel 37, bag 3,451, item 35, 2 pp.

Stability to oxidation of lubricants obtained by the polymerization of liquid monoolefins in the presence of AlCl₃ is increased by heating the oils, directly after polymerization in the presence of the low-boiling fractions with small amounts (0.5-2.5%) of AlCl₃ suitably with addition of 1-5% of the double AlCl₃ occurring in the synthesis of lubricating oils, for several hours at temperatures higher than those used in the synthesis. Suitable temperatures are 170°-180°. By this method higher yields are obtained, the loss of lubricating oil is less, and the resistance to oxidation is improved.