Patent ID: 8658575

Claim:
A process for the preparation of a composition of insulating fluid, which comprises fractionating heavy alkylate fractions of linear alkyl benzene (LAB) or crackers, at a temperature in the range of 210-310° C., under vacuum distillation to obtain dialkylbenzenes having 14 to 18 carbon atoms and viscosity in the range of 10-20 cst at about 27° C., removing the oxidized product from the above alkyl fractions to obtain a base stock, mixing 98.0-99.8 wt % of the above said base stock, at least one anti-oxidant in the range of 0.006-0.05 W %, at least one detergent-depressant in the range of 0.05-0.15 W %, at least one anti-foaming agent in the range of 0.01 to 1.0 W %, at least one pour point depressant in the range of 0.01 to 1.0 W %, at least one corrosion inhibitor in the range of 0.10-0.03 W %, under stirring, at a temperature in the range of 50-90° C. to obtain the desired insulating oil composition.