| abstract |
Lubricating composition for two-stroke engines comprising: a major quantity of an oil at least of lubricating viscosity not containing oils with a viscosity greater than or equal to 100 centistokes at 40 ° C; a quantity, sufficient to reduce or prevent pre-seizure of the piston, of a mixture of (A) at least one phenol chosen from (A-1) an aminophenol and (A-2) a reaction product of a nitrophenol and d 'an amino compound, and (B) at least one ashless dispersant. These compositions can also contain up to 10% by weight of (c) at least one polyalkene with an average molecular weight of between approximately 500 and 2500. Since the lubricating compositions for two-stroke engines are often mixed with the fuels before or during combustion, the invention presented here also extends to fuel-lubricant mixtures. The inventors have found that the compositions referred to above have the effect of preventing pre-seizure of the piston while also having the advantage of contributing to the lubrication of this organ, of preventing the formation of deposits, of ensuring protection against bonding of the segments, limiting the obturation of the exhaust lights as well as the emission of visible smoke. According to another embodiment, the lubricating compositions are free of isostearic acid, or derivatives of this acid. |