PATENTS

3122.----- [RUHRCHEMIE, A. G.]  [Process for Preparing Lubricants Highly Resistant to Oxidation.]  German Patent Appl. --, R 431, filed Feb. 9, 1939.  TOM Reel 37, bag 3,451, item 35, 4 pp.

According to a previous German Patent Appl. R 94,081 (abs. 3152), high molecular hydrocarbon oils are produced by cracking the liquid hydrocarbons b. > 150°, obtained by the catalytic hydrogenation of CO and by polymerizing the cracked gasoline thus obtained with known condensation agents.  It has also been stated in German Patent Appl. R 97,688 (abs.2917) hat it is of advantage in producing synthetic lubricants to use only such cracked gasolines whose various fractions show quite aefinite densities.  It has now been found that lubricants with special oxidation resistant properties can be prepared by separating the cracked gasoline into a higher and a lower boiling fraction and then polymerizing only the former fraction to lubricating oil.  The most suitable fraction is that above about 75° as this contains chiefly olefins with double end bonds and polymerizes most satisfactorily.  The lubricant thus obtained after separation of the condensation medium, is treated at about 170°-180° with a small amount of Al chloride or at 230°-250° with bleaching earth to improve the quality of the oil.