Abstract: A process for producing a lubricant base oil with low pour point and high aromaticity from a feedstock oil which is either a distillate fraction boiling at 250.degree. C. or above that is obtained from a paraffin base or mixed base crude or a deasphalted oil obtained from a vacuum distillation residual oil of said crude, and process comprising:(a) the step of bringing said feedstock oil into contact with a hydrofining catalyst in the presence of hydrogen and recovering a hydrofined oil;(b) the step of dewaxing said hydrofined oil and recovering the dewaxed oil;(c) the step of subjecting said dewaxed oil to extraction with a solvent having selective affinity for aromatic hydrocarbons so as to separate the feed into the raffinate portion and the extract portion, and removing the solvent from said extract portion to obtain an extract oil; and(d) the step of treating said extract oil by means of contact with a solid adsorbent or sulfuric acid.

Abstract: A lubricating oil composition for use in a Flon atmosphere is disclosed, which comprises a base oil having incorporated therein from 20 to 10,000 wt ppm of a higher fatty acid-modified silicone oil. The lubricating oil composition is excellent in both wear resistance and Flon stability.

Abstract: An electrical insulating oil, comprising:a base oil selected from the group consisting of a mineral oil, an alkylbenzene, and a mixture of a mineral oil and an alkylbenzene;a non-basic nitrogen content in an amount of 16 ppm or more; anda basic nitrogen content in an amount of 6% or less based on the weight of the non-basic nitrogen content.

Abstract: A lubricant composition that exhibits high wear resistance in a Flon atmosphere is disclosed. The composition comprises mineral oil, alkylbenzene, or a mixture of mineral oil and alkylbenzene as a base oil and it has added thereto an organic sulfur compound in an amount greater than a certain value.