| 摘要 |
<p>1305018 Lubricating oils and compositions SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ NV 14 May 1970 [16 May 1969] 25017/69 Heading C5E and C5F Alubricating base oil of high viscosity index is obtained by decomposing thiourea adducts formed by treating an oil base stock with thiourea. Adduct formation can be carried out using a solvent for the oil base stock, such as a light n-paraffin, an aromatic hydrocarbon, a halogenated hydrocarbon or a mixture of these with each other or with a ketone, and a solvent for the thiourea, such as water monohydric or polyhydric alcohols, liquid ammonia, methylamine or a mixture of these. The adduct can be decomposed by hot ammonia or water and the hydrocarbon oil formed can be dewaxed by urea or solvent dewaxing, e.g. with a mixture of methyl ethyl ketone and toluene. Suitable feeds have initial boiling points of at least 300‹ C. and are vacuum distillates or vacuum residues, catalytically cracked fractions, shale oil fractions and heavy cycle oil and can have been treated by deosphalting, extraction with furfural, used dewaxing, solvent dewaxing and/or hydrotreating. A particular feed can be formed by catalytic isomerization of wax with the non-adducted portion being recycled to the isomerization process. The oil formed by the decomposition of the thiourea adduct can be blended with spindle oil, light machine oil or bright stock and can be used as a lubricant containing additives such as 4,4<SP>1</SP>-methylene bis 2,6-di-t-butylphenol and overbased calcium (C 14 -C 18 ) alkyl salicylate.</p> |
