| abstract |
(57) [Problem] To provide a metal working oil composition for copper and a copper alloy which has good workability and does not show discoloration of copper. SOLUTION: A lubricating base oil comprises (a) benzotriazole or a derivative thereof, (b) benzimidazole or a derivative thereof, (c) benzopyrazole or a derivative thereof, (d) a benzothiazole derivative, and (e) a benzoxazole derivative. , (F) a metal working oil composition for copper and copper alloys, comprising at least one azole compound selected from thiadiazole derivatives in an amount of 0.1 to 10% by weight based on the total amount of the composition. |