LUBRICATION METHOD AND LUBRICATING OIL COMPOSITIONS Russian patent published in 2015 - IPC C07C211/51 C10M133/12 C07C209/24 

FIELD: chemistry.

SUBSTANCE: invention relates to novel N,N'-tetra-aliphatic hydrocarbyl phenylenediamines of formula (I), which can be used as ash-free TBN sources, and to a crankcase lubricating oil composition. The composition contains a basic amount of oil with viscosity which is suitable for lubrication and not less than 50 wt % of one or more said N,N'-tetra-aliphatic hydrocarbyl phenylenediamines. The invention also relates to a method of lubricating surfaces of a compression ignition internal combustion engine during operation thereof. In formula (I) each of R¹, R², R³ and R⁴ is independently an aliphatic hydrocarbyl group selected from an alkyl group having 3 to 12 carbon atoms, wherein at least one of R¹, R², R³ and R⁴ is an alkyl group, branched in an alpha position to the bonded nitrogen and having 3 to 12 carbon atoms, and at least one of R¹, R², R³ and R⁴ is an alkyl group, branched a beta position to the bonded nitrogen, having 4 to 12 carbon atoms; each R⁵ is independently hydrogen or an aliphatic hydrocarbyl group, selected from an alkyl group having 1 to 12 carbon atoms; and n ranges from 0 to 4. The preferable compounds are N,N'-di-(sec-butyl)-N,N'-di-(2-ethylhexyl)-p-phenylenediamine and N,N'-di(1,3-methylbutyl)-N,N′-di(2-ethylhexyl)-p-phenylenediamine.

EFFECT: compositions based on the compound of formula (I) are compatible with fluoroelastomeric sealing materials and satisfy copper plate corrosion test standards.

11 cl, 8 tbl, 6 ex