| 摘要 |
PROBLEM TO BE SOLVED: To provide a well balanced electric insulating oil which has excellent electric characteristics and thermal stability and can be manufactured economically in a simple method. SOLUTION: In the case a hydro-refining mineral oil and a synthetic hydrocarbon oil and the like are used as a base oil, such a base oil contains little of impurities contributing for an oxidation stability. If such an oil is made to contain approximately 0.5 to 10 wt.% of a bright stock, trace compositions necessary for improvement of a characteristics of the electric insulating oil can be retained and the electric insulating oil can be obtained which has a flash point (PMCC) of 130°C and a pour point of -40°C. COPYRIGHT: (C)2007,JPO&INPIT |
