| 摘要 |
PURPOSE:To obtain a lubricating oil composition for plastic working of aluminum excellent in especially the surface finish of the workpiece by mixing an olefin having a specified structure as a base oil with a specified amount of a specified aromatic amine. CONSTITUTION:This composition is prepared by mixing an 8-20C branched olefin as a base oil with 0.01-5wt.%, based on the whole composition, phenyl-alpha- naphthylamine represented by formula I (where R<1> is H or 1-24 C alkyl). This composition is further mixed with zinc dithiophosphate represented by formula II (wherein R<2> to R<5> are each a 1-24 C hydrocarbon group) to obtain a composition further improved in oxidation stability. The amount of the zinc dithiophosphate added is 0.005-5wt.%. The branched olefin is obtained by oligomerizing propylene, butene, isobutylene or the like. The amine of formula I is desirably one in which R<1> is H or an 8-16 C branched alkyl. |
