Lubricant composition for preventing pre-ignition

Abstract

The present invention relates to the use of a lubricant composition comprising (i) at least one boron derivative; and (ii) at least one base oil, for preventing and/or reducing pre-ignition, in particular at low speed, in a vehicle engine, wherein said composition is used during at least one change interval without the addition of a new lubricant composition, the content of boron in the composition being between 150 ppm and 350 ppm by weight.

1 .- 15 . (canceled) 
     
     
         16 . A method for preventing and/or reducing preignition in a vehicle engine, the method comprising contacting the engine with a lubricant composition in the course of at least one oil change interval without adding fresh lubricant composition, the lubricant composition comprising:
 (i) at least one boron derivative; and   (ii) at least one base oil;   wherein the lubricant composition comprises boron in an amount ranging from 150 to 350 ppm by weight.   
     
     
         17 . The method of  claim 16 , wherein the boron derivative is chosen from boric acid derivatives, boronic acid derivatives, boronates, borates, borated dispersants, borated detergents, simple orthoborates, borate epoxides, borate esters, or mixtures thereof. 
     
     
         18 . The method of  claim 16 , wherein the content of boron ranges from 150 to 300 ppm by weight. 
     
     
         19 . The method of  claim 16 , wherein the base oil is chosen from the oils of group III, the oils of group IV, or mixtures thereof. 
     
     
         20 . The method of  claim 16 , wherein the lubricant composition further comprises at least one antioxidant additive. 
     
     
         21 . The method of  claim 20 , wherein the at least one antioxidant additive is present in an amount ranging from 0.05% to 2% by weight, relative to the total weight of the lubricant composition. 
     
     
         22 . The method of  claim 16 , wherein the lubricant composition further comprises at least one detergent additive different from the boron derivative, chosen from alkaline-earth metal salts. 
     
     
         23 . The method of  claim 16 , wherein the lubricant composition further comprises at least one viscosity index-enhancing additive chosen from hydrogenated or non-hydrogenated homopolymers or copolymers, styrene, butadiene, or isoprene. 
     
     
         24 . The method of  claim 23 , wherein the composition comprises from 2% to 15% by weight of viscosity index-enhancing additive, relative to the total weight of the composition. 
     
     
         25 . A method for preventing and/or reducing preignition in a vehicle engine, the method comprising adding at least one boron derivative to a lubricant composition comprising at least one base oil in an amount to provide a lubricant composition comprising boron in an amount ranging from 150 to 350 ppm by weight, wherein the lubricant composition is used in the course of at least one oil change interval without adding fresh lubricant composition. 
     
     
         26 . A method for limiting the degradation of performance in terms of preventing and/or reducing preignition in a vehicle engine of a lubricant composition comprising at least one base oil, after its use in the course of at least one oil change interval without adding fresh lubricant composition, the method comprising adding at least one boron derivative to a lubricant composition comprising at least one base oil in an amount to provide a lubricant composition comprising boron in an amount ranging from 150 to 350 ppm by weight. 
     
     
         27 . A method for increasing the ignition temperature, measured by high-pressure differential scanning calorimetry, of a lubricant composition comprising adding at least one boron derivative to said lubricant composition, said composition being used in the course of at least one oil change interval without adding fresh lubricant composition, relative to a spent lubricant composition free of any boron derivative compound, the content of boron in the composition being between 150 ppm and 350 ppm by weight. 
     
     
         28 . A process for preventing and/or reducing preignition in a vehicle engine, comprising:
 a) contacting the engine with a lubricant composition comprising at least one base oil and at least one boron derivative, wherein the lubricant composition comprises boron in an amount ranging from 150 to 350 ppm by weight; and   b) running the engine in the course of at least one oil change interval, without adding fresh lubricant composition.   
     
     
         29 . The process of  claim 28 , wherein the boron derivative is chosen from boric acid derivatives, boronic acid derivatives, boronates, borates, borated dispersants, borated detergents, simple orthoborates, borate epoxides, borate esters, or mixtures thereof. 
     
     
         30 . A method for preventing and/or reducing preignition in a vehicle engine, comprising at least a step of contacting the engine with a lubricant composition comprising:
 (i) at least one boron derivative, the content of boron in the composition being between 150 ppm and 350 ppm by weight; and   (ii) at least one base oil;   wherein the lubricant composition has undergone iron-catalyzed oxidation at a temperature ranging from 150° C. to 170° C. for a time ranging from 120 hours to 150 hours, according to the GFC Lu-43A-11 method.   
     
     
         31 . The method of  claim 16 , wherein the lubricant composition is contacted with the engine over a distance travelled by the vehicle ranging from 10,000 km to 30,000 km, without adding fresh lubricant composition. 
     
     
         32 . The method of  claim 16 , wherein the content of boron ranges from 150 to 260 ppm. 
     
     
         33 . The method of  claim 20 , wherein the antioxidant additive is chosen from diphenylamine, phenols, phenol esters, or mixtures thereof. 
     
     
         34 . The method of  claim 16 , wherein the lubricant composition further comprises at least one detergent additive different from the boron derivative, chosen from calcium salts, magnesium salts, and mixtures thereof. 
     
     
         35 . A method for preventing and/or reducing low-speed preignition in a vehicle engine of a motor vehicle, the method comprising contacting the engine with a lubricant composition in the course of at least one oil change interval without adding fresh lubricant composition, the lubricant composition comprising:
 (i) at least one boron derivative; and   (ii) at least one base oil;   wherein the lubricant composition comprises boron in an amount ranging from 150 to 350 ppm by weight.