| 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-diphenylethane, and (g) 1,1-diphenylethylene; and is characterized in that the proportion of solid phase at a temperature of -40 DEG 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: <MATH> 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>). |
