| 摘要 |
A synthetic lubricating oil composition comprises a base oil comprising at least 40 wt. per cent of an ester lubricating oil, from 1.5-5.0 wt. per cent, based on the base oil, of an aromatic amine antioxidant, and 0.5-5.0 wt. per cent of a copolymer of at least one unsaturated ester of a C2-20 aliphatic alcohol and a carboxylic acid with either 2-N-vinyl pyrrolidene or maleic anhydride. Many types of ester lubricating oils are described including dicarboxylic acid diesters, fully esterified glycols and polyglycols, full esters of polyhydric alcohols (e.g. T.M.P.), and complex esters, and these esters may be blended with glycol ethers or polyglycol ethers to give a mixed base oil. Many examples of these esters and ethers are given. The amine antioxidants include phenothiazine, phenyl-a -naphthylamine and dioctyl diphenylamine amongst others. The copolymer additives are also extensively exemplified and include a mixed fumarate/vinyl acetate/maleic anhydride copolymer, and copolymers available commercially under the Trade Name "Acryloid." Other additives which may be present include chlorinated bi- and poly-phenyls, half esters or tetrabasic aromatic acids such as pyromellitic and prehnitic acids, dimethyl silicene and methyl phenyl silicane polymers, and tricresyl phosphate. |
