AVIATION HYDRAULIC LIQUID Russian patent published in 2001 - IPC

FIELD: special-destination liquids. SUBSTANCE: liquid contains inflammation-resistant base component - phosphoric acid ester containing 10-90% tri-C4-C5-alkyl phosphate, in which linear or branched alkyl groups are linked to phosphate moiety through primary carbon atoms, from 0 to about 70% dialkylaryl phosphate, in which alkyl radicals are such as defined above. Liquid also includes acid acceptor, antierosion reagent, viscosity index stabilizer, and antioxidant. Viscosity index stabilizer can be represented by polymer based on methacrylic acid ester, antierosion reagent can be perfluoroalkanesulfonic acid salt, and acid acceptor can be 3,4-epoxycyclohexanecaboxylate or diepoxide. Acids can be accepted by di(alkylphenyl)amine, and phenolic antioxidant is constituted by mixture of 2,4,6-trialkylphenol and hindered polyphenol selected from group including bis(3,5-dialkyl-4-hydroxyaryl)methane, 1,3,5-trialkyl- 2,4,6-tris(3,5-di-tert-butyl-4-hydroxyaryl)benzene, and their mixtures. Composition advantageously contains 4,5-dihydroimidazole compound to provide liquid stability. EFFECT: increased thermal, hydrolytic, and oxidation stabilities. 41 cl, 13 dwg, 15 tbl, 13 ex