| 摘要 |
<p>There are provided a heat resistant lubricating oil composition comprising a lubricating base oil comprising an organic ester or a mixture of an organic ester and a polyphenyl ether or an organopolysiloxane, and incorporated with from 0.05% by weight to 10% by weight, based on the total weight of the lubricating oil composition, of a polyphenyl thioether represented by the following general formula ÄIÜ: <CHEM> where R<1>, R<2> and R<3> which may be identical or different with each other each represent a hydrogen atom or a hydrocarbon group of 1 to 24 carbon atoms, x, y and z which may be identical or different with each other each represent an integer of 1 to 4 and m represent 0 or an integer of 1 to 3, a heat resistant lubricating oil composition containing, as a lubricating base oil, at least from 10% by weight to 90% by weight of a component selected from the group consisting of an organic ester, and a mixture of an organic ester and a polyphenyl ether or an organopolysiloxane and from 90% by weight to 10% by weight of the polyphenyl thioether represented by the general formula ÄIÜ described above, as well as a method of preventing oxidation of a heat resistant lubricating oil composition, further, a process for producing a polyphenyl thioether including a purification treatment for the improvement of the weather resistance of the polyphenyl thioether. The heat resistant lubricating oil composition obtained by the present invention has high heat resistance and oxidation resistance under a high temperature condition and can withstand severe working conditions such as in jet engines or gas turbines.</p> |
