PROCESS FOR PREPARING AN AROMATIC OIL AND NON-DISCOLORING RUBBER COMPOSITION CONTAINING SAID OIL

摘要

A transformer oil having a sludge-free Doble life of at least 64 hours can be prepared from a severely hydrorefined naphthenic oil having a viscosity from 40 to 200 SUS at 100 DEG F. and an ultraviolet absorptivity of less than 0.04 in the 335 millimicron region by a process comprising increasing the content in the hydrorefined oil of polynuclear hydrocarbons having at least four condensed aromatic rings until the 335 absorptivity is in the range of 0.04 to 2.5. An especially useful novel oil having a sludge-free Doble life of at least 100 hours with a total acid number less than 0.1, which can be prepared by the present process, has a 335 UVA in the range of 0.06 to 2.0 and a composition such that the ratio of the ultraviolet absorptivity at 335 millimicrons to the absorptivity at 330 millimicrons is no less than 1.0, has a sulfur content in the range of 25 to 800 p.p.m. and contains less than 25 p.p.m. of nitrogen.