| 摘要 |
PROBLEM TO BE SOLVED: To provide a process oil reduced in a content of polycyclic aromatic compounds said to be harmful to humans and retaining conventional performances. SOLUTION: A process oil having a polycyclic aromatic content of below 3 mass % is produced by extracting a mixed oil containing a residual oil. It is desirable that the process oil has a polycyclic aromatic content of below 3 mass %, an aromatic content of at least 18 mass %, a polar compound content of 11-25 mass %, a kinematic viscosity of 10-70 mm2/s at 100 deg.C, and a flash point of at least 210 deg.C. |
