United States of America as Represented by the Secretary of the Air Force

Kalathil C Eapen

Carl E Snyder, Jr

Lois J Gschwender

Grace J Chen

Loomis S Chen

A lubricant composition comprises a perfluorinated polyalkylether base fluid (PFPAE) and an oxidation-corrosion inhibiting amount of a perfluoro-substituted benzothiazole or bis-benzothiazole. The benzothiazole compound additive exhibits excellent solubility in the base fluid and possesses outstanding low volatility characteristics. As a result, the lubricant composition functions as a noncorrosive, stable material suitable for long term applications over a wide temperature range (-65.degree. F. to &gt;600.degree. F.) in an oxidative environment. The perfluoro-substituted benzothiazoles and bis-benzothiazoles have the formula: Q--R.sub.f or Q--R.sub.f '--Q, wherein Q is ##STR1## wherein R.sub.f is a linear or branched perfluoroalkylether group containing at least one ether linkage and R.sub.f ' is a linear or branched perfluoroalkyleneeher group containing at least one ether linkage. In formulating the lubricant composition of this invention, an oxidation-corrosion inhibiting amount of the substituted benzothiazole is dissolved in the PFPAE base fluid. The amount of the benzothiazole employed generally ranges from about 0.05 to 5.0 weight percent, preferably about 0.5 to 2.0 weight percent, based on the weight of the base fluid. This provides a lubricant containing an amount of oxidation-corrosion inhibiting additive that is adequate for long term applications at elevated temperatures while maintaining excellent formulation stability after storage at low temperatures for long periods of time.

Perfluorinated polyether lubricant compositions

Perfluoroalkylether (PFAE) tertiary mono- and poly-alcohols of the general structure: ##STR1## wherein R.sup.1 and R.sup.3 represent perfluoroalkyl groups having from one to fifty carbon atoms or PFAE groups having 2-50 carbon atoms and 1-49 oxygen atoms; R.sup.2 represents a PFPAE group having 3-50 carbon atoms and 1-48 oxygen atoms; A represents perfluoroalkylene groups containing 2-30 carbon atoms or perfluoroalkyleneether groups having 2-30 carbon atoms and 1-29 oxygen atoms; and n is an integer having a value ranging from zero to ten; and wherein the alcohol contains at least 12 carbon atoms per molecule. The perfluoroalkylether (PFAE) tertiary mono- and poly-alcohols are mixed with perfluoropolyalkylether fluids in an amount ranging from 0.01 to 1.00 weight percent to provide fluids having improved antiwear properties.

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Fairborn, OH, United States of America

Kalathil C Eapen