Verfahren zur Herstellung hochwertiger Schmieroele

Cylinder oils and similar high viscosity lubricating-oils are treated to remove constituents of high molecular weight (400--1000) and to the treated oil, synthetic hydrocarbon products of high molecular weight soluble in the oil and having a higher hydrogen content than the constituents which have been removed, are added. The constituents are removed by treatment with liquefied hydrocarbons which are gaseous at ordinary temperature such as methane, ethane, propane, butane, pentane, ethylene, butylene or mixtures which may contain acetylene. The treatment is carried out below the critical temperature of the solvent. Resin, asphalts and hard or soft paraffin wax may be separated by a preliminary treatment with benzine, or by a two-stage treatment with liquefied hydrocarbons, the resins &c. separating in the first stage. The added hydrocarbon products may be those prepared according to Specifications 349,071 and 407,379, hydrogenated polymerization products of styrene, indene, olefines and diolefines such as isobutylene, or hydrorubber having a molecular weight of 2000--3000.