摘要 |
An electrical insulating oil composition having good low temperature characteristics which comprises at least 4 members selected from the group consisting of (a) m-ethylbiphenyl, (b) p-ethylbiphenyl, (c) o-benzyltoluene, (d) m-benzyltoluene, (e) p-benzyltoluene, (f) 1,1-diphenyl-ethane, and (g) 1,1-diphenylethylene; and is characterized in that the proportion of solid phase at a temperature of -40.degree.C of the electrical insulating oil composition is not more than 45% by weight and the proportion of the total quantity of solid phase is calculated according to the following general equation of solid-liquid equilibrium: Xi = wherein Xi is the equilibrium mole fraction of a component i in the liquid phase of the composition, .DELTA.H? is the heat of fusion (cal.mol-1), T? is the melting point (K), T is the temperature (K), and R is the gas constant (cal.mol-1.K-1). |