Method Of Lubricating An Internal Combustion Engine

Abstract

The disclosed technology provides a method of lubricating a compression-ignition internal combustion engine with a maximum laden mass over 2,700 kg comprising supplying to the engine a lubricating composition comprising: an oil of lubricating viscosity, a 300 TBN or higher alkaline earth metal sulfonate detergent having a metal ratio of 10 to 40, an alkaline earth metal sulfonate detergent having a metal ratio of 3 to 9, and a TBN of 81 to 180 mg KOH/g, wherein the sulfonate detergents provide a total amount of sulfonate substrate of 1 wt % to 3 wt % of the lubricating composition, 0.1 to 1.2 wt % of antioxidant, wherein at least 20 wt % of the antioxidant is a phenolic antioxidant, a borated compound present in an amount to deliver 25 ppm to 300 ppm of boron, the lubricating composition has a sulfated ash content of 0.5 wt % to not more than 1.5 wt %, and the lubricating composition has a TBN of 6.5 to 15 mg KOH/g.

1 . A method of lubricating a compression-ignition internal combustion engine with a maximum laden mass over 2,700 kg comprising supplying to the engine a lubricating composition comprising:
 an oil of lubricating viscosity,   a 300 TBN or higher alkaline earth metal sulfonate detergent having a metal ratio of 10 to 40,   an alkaline earth metal sulfonate detergent having a metal ratio of 3 to 9, and a TBN of 81 to 180 mg KOH/g (as measured by ASTM D2896-11),   wherein the sulfonate detergents provide a total amount of sulfonate substrate of 0.8 wt % to 3 wt %, or 0.9 wt % to 3 wt %, or 1 wt % to 3 wt % of the lubricating composition,   0.1 to 1.2 wt % of antioxidant, wherein at least 20 wt % of the antioxidant is a phenolic antioxidant,   a borated compound present in an amount to deliver 25 ppm to 300 ppm of boron and the borated compound is chosen from
 a borate-ester, 
 a borated dispersant, and 
   
       wherein
 the lubricating composition has a sulfated ash content of 0.4 wt % to 2 wt %, or 0.5 wt % to 1.8 wt %, or 0.5 wt % to not more than 1.5 wt %, and 
 the lubricating composition has a TBN of 6.5 to 15 mg KOH/g (as measured by ASTM D2896-11). 
 
     
     
         2 .- 3 . (canceled) 
     
     
         4 . The method of  claim 1 , wherein the lubricating composition is characterized as having (i) a sulfur content of 0.5 wt % or less, (ii) a phosphorus content of 0.15 wt % or less, and (iii) a sulfated ash content of 0.5 wt % to 1.5 wt % or less. 
     
     
         5 . (canceled) 
     
     
         6 . The method of  claim 1 , wherein the lubricating composition is characterized as having a sulfated ash content of 0.9 wt % to 1.4 wt %, or 1.05 wt % to 1.2 wt %. 
     
     
         7 . The method of  claim 1 , wherein the oil of lubricating viscosity comprises a base oil selected from one or more of an API Group I, II, III, IV, V, or mixtures thereof. 
     
     
         8 .- 13 . (canceled) 
     
     
         14 . The method of  claim 1 , wherein the antioxidant comprises an aminic antioxidant. 
     
     
         15 . The method of  claim 14 , wherein the aminic antioxidant comprises at most 60 wt %, of the antioxidant. 
     
     
         16 . The method of  claim 1 , wherein the antioxidant comprises a sulfurized olefin antioxidant. 
     
     
         17 . The method of  claim 16 , wherein the sulfurized olefin antioxidant comprises at most 60 wt %, of the antioxidant. 
     
     
         18 . The method of  claim 1 , wherein the antioxidant comprises a phenolic or an aminic antioxidant or mixtures thereof, and wherein the antioxidant is present at 0.1 wt % to 3 wt %, or 0.5 wt % to 2.75 wt %, or 1 wt % to 2.5 wt %. 
     
     
         19 . The method of  claim 1 , wherein the lubricating composition has a total base number (TBN) content of 7 to 14, or 7.5 to 12 mg KOH/g. 
     
     
         20 . (canceled) 
     
     
         21 . The method of  claim 1 , wherein the sulfonate detergents deliver 1.05 to 1.2 wt %, or 1.05 to 1.1 wt % of substrate to the lubricating composition. 
     
     
         22 .- 28 . (canceled) 
     
     
         29 . The method of  claim 1 , wherein the lubricating composition comprises 0 wt % to 0.2 wt %, or 0 wt % to 0.1 wt % of a phenolic based detergent. 
     
     
         30 . The method of  claim 29 , wherein the lubricating composition comprises 0 wt % of a phenolic based detergent. 
     
     
         31 .- 34 . (canceled) 
     
     
         35 . The method of  claim 1 , wherein the lubricating composition further comprises a dispersant viscosity modifier. 
     
     
         36 . The method of  claim 35 , wherein the dispersant viscosity modifier is an olefin copolymer further functionalized with a dispersant amine group. 
     
     
         37 .- 40 . (canceled) 
     
     
         41 . The method of  claim 35 , wherein the dispersant viscosity modifier is prepared by:
 grafting an olefinic carboxylic acid acylating agent onto a polymer of 15 to 80 mole percent of ethylene, from 20 to 85 mole percent of C 3-10  alpha monoolefin, and from 0 to 15 mole percent of non-conjugated diene or triene, said polymer having an average molecular weight ranging from 5000 to 500,000; and   reacting the resultant grafted polymer with an amine.   
     
     
         42 .- 43 . (canceled) 
     
     
         44 . The method of  claim 1 , wherein the lubricating composition further comprises a non-borated dispersant. 
     
     
         45 . (canceled) 
     
     
         46 . The method of  claim 44 , wherein the non-borated dispersant is an amine-functionalized additive derived from an amine having at least 4 aromatic groups, at least one —NH 2  functional group, and at least 2 secondary or tertiary amino groups. 
     
     
         47 .- 53 . (canceled) 
     
     
         54 . The method of  claim 1 , wherein the borated compound is a borate ester represented by the formulae: 
       
         
           
           
               
               
           
         
       
       where each R is independently an organic group and any two adjacent R groups may together form a cyclic group, or
 wherein the boron-containing compound is borate ester represented by the formula 
 
       
         
           
           
               
               
           
         
       
       wherein R, R 1 , R 2 , R 3  and R 4  are independently hydrocarbyl groups of 1 to 12 carbon atoms; and R 5  and R 6  are independently alkylene groups of 1 to 6 carbon atoms, and in one embodiment 2 to 4 carbon atoms. 
     
     
         55 .- 61 . (canceled) 
     
     
         62 . The method of  claim 1 , wherein the borate ester is represented by one or more of the formulae:
   (RO) 3 B, or (RO) 2 B—O—B(OR) 2,  or
   
       
         
           
           
               
               
           
         
       
       wherein each R is independently an alkyl group having 10 to about 32 carbon atoms and having a branch at the β or higher position. 
     
     
         63 . The method of  claim 1 , wherein the borate ester comprises a trialkylborate. 
     
     
         64 . (canceled) 
     
     
         65 . The method of  claim 1 , wherein the lubricating composition further comprises a zinc dialkyldithiophosphate. 
     
     
         66 . The method of  claim 65 , wherein the zinc dialkyldithiophosphate is a primary zinc dialkyldithiophosphate, or a secondary zinc dialkyldithiophosphate 
     
     
         67 .- 68 . (canceled) 
     
     
         69 . The method of  claim 65 , wherein the zinc dialkyldithiophosphate is present to deliver 100 ppm to 1000 ppm, or 200 ppm to 900 ppm, or 350 ppm to 900 ppm of phosphorus. 
     
     
         70 . The method of  claim 1 , wherein the internal combustion engine has a steel surface on a cylinder bore, cylinder block, or piston ring. 
     
     
         71 . The method of  claim 1 , wherein the internal combustion engine has a surface of steel, or an aluminium alloy, or an aluminium composite.