Patent ID: 7846882

Claim:
An electrical oil formulation consisting essentially of: (i) at least 80 wt % of a base oil component comprising a paraffinic base oil having a paraffin content of greater than 80 wt % paraffins and a saturates content of greater than 98 wt % and comprising a series of iso-paraffins having n, n+1, n+2, n+3 and n+4 carbon atoms and wherein n is between 20 and 35; (ii) an phenolic or amine anti-oxidant additive; (iii) an aromatic anti-gassing compound; (iv) a copper passivator additive; and (v) a sulphur or phosphorus containing additive; wherein the base oil component has a flash point of at least 170° C., as determined by ISO 2592; wherein the paraffinic base oil is obtained by hydroisomerisation of a Fischer-Tropsch derived wax, followed by dewaxing; and wherein the formulation comprises between 0.05 and 10 wt % of an aromatic anti-gassing compound selected from the group consisting of: tertrahydronaphthalene, diethylbenzene, di-isopropylbenzene, mixtures of alkylbenzenes, and mixtures of 2,6-di-t-butyl phenol and 2,6-di-t-butyl cresol.