Zinc free lubricating compositions and methods of using the same

Abstract

The instant disclosure generally relates to lubricating compositions having an oil of lubricating viscosity, an ashless phosphorus-containing antiwear agent an alkaline earth metal detergent, an ashless antioxidant, and an ashless dispersant where the lubricating compositions are substantially free of zinc and methods of lubricating an engine with such lubricating compositions. The instant lubricating compositions are useful as alternative lubricating compositions the reduce and/or eliminate zinc to achieve a desired performance goal of the lubricating composition.

1 . A lubricant composition comprising:
 a base oil of lubricating viscosity;   an ashless phosphorus-containing antiwear agent;   an alkaline earth metal detergent;   an ashless antioxidant; and   an ashless dispersant,   where the lubricant composition is substantially free of zinc.   
     
     
         2 . The lubricant composition of  claim 1 , wherein the oil of lubricating viscosity comprises 80 to 95 wt % of the lubricant composition. 
     
     
         3 . (canceled) 
     
     
         4 . The lubricant composition of  claim 1 , wherein the ashless phosphorous-containing antiwear agent is an organo-phosphorous antiwear agent. 
     
     
         5 . The lubricant composition of  claim 1 , wherein the ashless phosphorous-containing antiwear agent is selected from a phosphite, a (thio)phosphate, a (thio)phosphate amine salt, and combinations thereof. 
     
     
         6 . The lubricant composition of  claim 5 , wherein the (thio)phosphate amine salt is an alkyl phosphate amine salt. 
     
     
         7 . The lubricant composition of  claim 6 , wherein at least 30 mole percent of the phosphorous atoms in the alkyl phosphate amine salt are in an alkyl pyrophosphate salt structure. 
     
     
         8 . The lubricant composition of  claim 7 , wherein the amine alkyl pyrophosphate salt comprises a species represented by formula (I) or (II): 
       
         
           
           
               
               
           
         
         wherein each R 1  is independently a primary alkyl group of about 3 to about 12 carbon atoms and each R 2  is independently hydrogen or a hydrocarbyl group or an ester-containing group, and at least one R 2  group is a hydrocarbyl group or an ester-containing group; or wherein the —OH group is replaced by an —OR 1  group, or wherein one or more —OR 1  groups are replaced by —OH groups, or wherein an R 1  group is replaced by a phosphorus-containing group. 
       
     
     
         9 . The lubricant composition of  claim 7 , wherein the amine alkyl pyrophosphate salt comprises a species represented by formula (I) or (II): 
       
         
           
           
               
               
           
         
         wherein each R 1  is independently a primary alkyl group of about 3 to about 12 carbon atoms and each R 2  is independently hydrogen or a hydrocarbyl group or an ester-containing group, and at least one R 2  group is a hydrocarbyl group or an ester-containing group. 
       
     
     
         10 . The lubricant composition of  claim 1 , wherein the ashless phosphorus-containing antiwear agent is present in the lubricant composition in amount of from 0.1 to 1.5 wt %. 
     
     
         11 . (canceled) 
     
     
         12 . (canceled) 
     
     
         13 . (canceled) 
     
     
         14 . The lubricant composition of  claim 1 , wherein the ashless phosphorus-containing antiwear agent is present in amount to deliver from 500 to 900 ppm phosphorous to the lubricant composition. 
     
     
         15 . (canceled) 
     
     
         16 . (canceled) 
     
     
         17 . (canceled) 
     
     
         18 . (canceled) 
     
     
         19 . The lubricant composition of  claim 1 , wherein the alkaline earth metal detergent is selected from an alkaline earth metal sulfonate, phenate, and salicylate. 
     
     
         20 . The lubricant composition of  claim 19 , wherein the metal of the alkaline earth metal detergent is selected from calcium and magnesium. 
     
     
         21 . The lubricant composition of  claim 20 , wherein the alkaline earth metal detergent is a calcium sulfonate detergent. 
     
     
         22 . The lubricant composition of  claim 20 , wherein the alkaline earth metal detergent is a magnesium sulfonate detergent. 
     
     
         23 . The lubricant composition of  claim 1 , wherein the alkaline earth metal detergent is present in the lubricant composition in an amount of from 0.3 to 2.5 wt %. 
     
     
         24 . (canceled) 
     
     
         25 . (canceled) 
     
     
         26 . The lubricant composition of  claim 1 , wherein the alkaline earth metal detergent comprises a mixture of alkaline earth metal detergents and the mixture is present in the lubricating composition in an amount of from 0.8 to 2.0 wt %. 
     
     
         27 . The lubricant composition of  claim 26 , wherein the mixture of alkaline earth metal detergents includes 0.4 to 0.8 wt % of a calcium sulfonate detergent and 0.6 to 1.1 wt % of a magnesium sulfonate detergent based on the total weight of the lubricant composition. 
     
     
         28 . The lubricant composition of  claim 1 , wherein the ashless antioxidant is selected from an arylamine, diarylamine, an alkylated arylamines, an alkylated diaryl amines, a phenols, a hindered phenols, a sulfurized olefins, and mixtures thereof. 
     
     
         29 . The lubricant composition of  claim 28 , wherein the antioxidant is an alkylated diarylamine. 
     
     
         30 . The lubricant composition of  claim 28 , wherein the antioxidant is a sulfurized olefin. 
     
     
         31 . The lubricant composition of  claim 1 , wherein the antioxidant is present in the lubricant composition in an amount of from 0.1 to 2.1 wt %. 
     
     
         32 . (canceled) 
     
     
         33 . The lubricant composition of  28 , wherein the antioxidant includes 0.8 to 1.3 wt % of an alkylated diarylamine and 0.1 to 0.5 wt % of a sulfurized olefin. 
     
     
         34 . The lubricant composition of  claim 1 , wherein the ashless dispersant is a polyisobutylene succinimide dispersant. 
     
     
         35 . The lubricant composition of  claim 34 , wherein the polyisobutylene succinimide dispersant is borated. 
     
     
         36 . The lubricant composition of  claim 1 , wherein the ashless dispersant is present in the lubricant composition in an amount of from 1 to 6 wt %, or 2 to 5 wt %, or 2.5 to 1.5 wt %. 
     
     
         37 . The lubricant composition of  claim 1 , wherein the ashless dispersant includes 0.8 to 1.6 wt % of a boron free polyisobutylene succinimide dispersant and 1.8 to 3.1 wt % of a borated polyisobutylene dispersant. 
     
     
         38 . (canceled) 
     
     
         39 . The lubricant composition of  claim 1 , wherein the ashless phosphorus-containing antiwear agent contains sulfur and the ratio of sulfur to phosphorous is less than 2 to 1. 
     
     
         40 . The lubricant composition of  claim 1 , wherein the lubricant composition is capable of reducing low speed pre-ignition events in a spark-ignited direct injection internal combustion engine operated under a load with a brake mean effective pressure (BMEP) of greater than or equal to 10 bars at speeds less than or equal to 3,000 rpm. 
     
     
         41 - 45 . (canceled)