Multigrade lubricating oils - of iow /30 type without polymer vi improvers, from hydrocracking of paraffin wax

摘要

Lubricating oil with dynamic viscosity of 24P max. at -17.8 degrees C and kinematic viscosity 7.0 cSt.min. at 98.9 degrees C, is made by hydrocracking a paraffin wax contg. =30 wt.% boiling at over 520 degrees C, obtd. from dewaxing of mineral oil residual fractions. Cracking is at 325-425 degrees C over a fluorine-contg. sulphided catalyst of Ni and/or Co and Mo and/or W, on an alimina carrier. The liquid product, of which 25-95 wt.% boils at over 400 degrees C, is fractionated and the residue with initial b.pt. of 350-470 degrees C is dewaxed and used as the lubricating oil base. The oils meet requirements for IOW/30 lubricating oils either without additives, or by addition of 5-12.5 wt.% additives excluding high mol. wt. V.I. improvers, which show insufficient shear stability in service and tend to break down forming deposits.