Use of zirconium compound to improve low speed pre-ignition performance

Abstract

A lubricating oil composition, and a method of reducing LSPI events employing the lubricating oil composition, including a base oil of lubricating viscosity, and an additive composition including: one or more overbased calcium-containing detergent(s) sufficient to provide at least 500 ppmw of calcium, and a zirconium-containing nanoparticle(s) and/or one or more zirconium-containing compound(s) sufficient to provide greater than 0 ppmw to 6000 ppmw of zirconium, wherein the nanoparticles have a size of from 1 to 500 nm, as measured by Dynamic Light Scattering, an amount of one or more molybdenum-containing compound present in an amount sufficient to provide no greater than 100 ppmw of molybdenum, and wherein the additive composition has a weight ratio of ppmw of zirconium provided by the zirconium-containing nanoparticle(s) and/or the one or more zirconium-containing compound(s) to the ppmw of calcium provided by the one or more overbased-calcium-containing detergent(s) of greater than about 0.01 to less than 5.

1 . A lubricating oil composition comprising:
 greater than 50 wt. % of a base oil of lubricating viscosity, and   an additive composition comprising:
 an amount of one or more overbased calcium-containing detergent(s) having a total base number of greater than 225 mg KOH/g, measured by the method of ASTM D-2896 sufficient to provide at least 500 ppmw of calcium to the lubricating oil composition, based on a total weight of the lubricating oil composition, and 
 an amount of zirconium-containing nanoparticle(s) and/or one or more zirconium-containing compound(s) sufficient to provide greater than 0 ppmw to 6000 ppmw of zirconium to the lubricating oil composition, based on the total weight of the lubricating oil composition, wherein the nanoparticles have a size of from 1 to 500 nm, as measured by Dynamic Light Scattering, 
 an amount of one or more molybdenum-containing compound present in an amount sufficient to provide no greater than 100 ppmw of molybdenum, based on a total weight of the lubricating oil composition, and 
 wherein the additive composition has a weight ratio of ppmw of zirconium provided by the zirconium-containing nanoparticle(s) and/or the one or more zirconium-containing compound(s) to the ppmw of calcium provided by the one or more overbased-calcium-containing detergent(s) of greater than about 0.01 to less than 5; from about 600 ppmw to about1000 ppmw of phosphorus, based on the total weight of the lubricating oil composition; and a total sulfated ash content of no greater than 1.5 wt. %, as measured by ASTM D874, based on the total weight of the lubricating oil composition. 
   
     
     
         2 . The lubricating oil composition of  claim 1 , wherein the lubricating oil composition is effective to reduce low speed pre-ignition events in a boosted internal combustion engine lubricated with the lubricating oil composition relative to a number of low speed pre-ignition events in the same engine lubricated with reference lubricating oil R-1; or the reduction of LSPI events is 50% or greater reduction and the LSPI events are LSPI counts during 25,000 engine cycles, wherein the engine is operated at 2000 revolutions per minute with brake mean effective pressure of 1,800 kPa,
 wherein R-1 is formulated from about 80.7 wt. % of a Group III base oil, 12.1 wt. % of passenger car motor oil additive package and 7.2 wt. % of a 35 SSI ethylene/propylene copolymer viscosity index improver, wherein the passenger car motor oil additive package is an API SN, ILSAC-GF-5, and ACEA A5/B5 qualified DI package and R-1 also showed the following properties and partial elemental analysis:   
       
         
           
                 
                 
               
                     
                 
                   10.9 
                   Kinematic Viscosity at 100° C., (mm 2 /sec) 
                 
                   3.3 
                   HTHS at 150° C., (cP) 
                 
                   2438 
                   calcium (ppmw) 
                 
                   <10 
                   magnesium (ppmw) 
                 
                   80 
                   molybdenum (ppmw) 
                 
                   772 
                   phosphorus (ppmw) 
                 
                   855 
                   zinc (ppmw) 
                 
                   9.0 
                   Total Base Number ASTM D-2896 (mg KOH/g) 
                 
                   165 
                   Viscosity Index 
                 
                     
                 
             
                
               
               
                
                
                
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         3 . The lubricating oil composition of  claim 1 , wherein the one or more overbased calcium-containing detergent(s) has a total base number of greater than 250 mg KOH/g or more as measured by the method of ASTM D-2896. 
     
     
         4 . The lubricating oil composition of  claim 1 , wherein the weight ratio of the ppmw of zirconium provided by the zirconium-containing nanoparticles and/or one or more zirconium-containing compound(s) to the ppmw of calcium provided by the one or more overbased calcium-containing detergent(s) is from 0.02 to 4. 
     
     
         5 . The lubricating oil composition of  claim 1 , wherein the lubricating oil composition contains greater than 1 ppmw of boron based on the total weight of the lubricating oil composition; or wherein the one or more overbased calcium-containing detergent(s) is present in an amount to provide at least 600 ppmw of calcium to less than 3000 ppmw calcium to the lubricating oil composition, based on the total weight of the lubricating oil composition. 
     
     
         6 . The lubricating oil composition of  claim 1 , wherein the zirconium-containing nanoparticle(s) and/or one or more zirconium-containing compound(s) is present in an amount to provide at least 5 ppmw zirconium to the lubricating oil composition, based on the total weight of the lubricating oil composition. 
     
     
         7 . The lubricating oil composition of  claim 1 , further comprising one or more magnesium-containing detergents present in an amount sufficient to provide greater than 500 ppmw to less 1000 ppmw of magnesium to the lubricating oil composition, based on the total weight of the lubricating oil composition; or wherein the one or more magnesium-containing detergents comprises an overbased magnesium sulfonate detergent having a total base number of greater than 225 mg KOH/g, as measured by the method of ASTM D-2896. 
     
     
         8 . The lubricating oil composition of  claim 1 , wherein the one or more zirconium-containing compound(s) is selected from zirconium (IV) oxides, zirconium (IV) sulfides, zirconium (IV) nitrates, zirconium (IV) alkoxides, zirconium phenates, zirconium carboxylates, zirconium salicylates, zirconium sulfonates, zirconium halides, and mixtures thereof. 
     
     
         9 . The lubricating oil composition of  claim 8 , wherein the one or more zirconium-containing compound(s) is a zirconium carboxylate, wherein the carboxylate group comprising from 3 to 20 carbon atoms. 
     
     
         10 . The lubricating oil composition of  claim 9 , wherein the zirconium carboxylate is selected from the group consisting of zirconium 2-ethylhexanoate, zirconium isooctanoate, zirconium isononanoate, zirconium isobutyrate, zirconium neopentanoate, zirconium neooctanoate, zirconium neononanoate, zirconium neodecanoate, and zirconium naphthenate; or
 wherein the one or more zirconium-containing compound(s) comprises an organometallic zirconium compound; or   wherein the lubricating oil composition comprising an amount of zirconium-containing nanoparticles.   
     
     
         11 . The lubricating oil composition of  claim 1 , wherein the lubricating oil composition is an engine oil composition. 
     
     
         12 . A method for reducing low-speed pre-ignition events in a boosted internal combustion engine comprising:
 lubricating a boosted internal combustion engine with a lubricating oil composition comprising greater than 50 wt. % of a base oil of lubricating viscosity and an additive composition comprising
 an amount of one or more overbased calcium-containing detergent(s) having a total base number of greater than 225 mg KOH/g, measured by the method of ASTM D-2896 sufficient to provide at least 500 ppmw calcium to the lubricating oil composition, based on a total weight of the lubricating oil composition, and 
 an amount of one or more zirconium-containing nanoparticles(s) and/or zirconium-containing compounds sufficient to provide greater than 0 ppmw to 6000 ppmw of zirconium to the lubricating oil composition, based on the total weight of the lubricating oil composition, wherein the nanoparticles have a size of from 1 to 500 nm, as measured by Dynamic Light Scattering, 
 at least one molybdenum-containing compound present in an amount sufficient to provide no greater than 100 ppmw of molybdenum, based on a total weight of the lubricating oil composition, and 
 wherein the additive composition has a weight ratio of the ppmw of zirconium provided by the zirconium-containing nanoparticles and/or one or more zirconium-containing compound(s) to the ppmw of calcium provided by the one or more overbased calcium-containing detergent(s) of greater than about 0.01 to less than 5, and 
 the lubricating oil composition contains from about 600 ppmw to about 1000 ppmw of phosphorus, based on the total weight of the lubricating oil composition; and a total sulfated ash content of no greater than 1.5 wt. %, as measured by ASTM D874, based on the total weight of the lubricating oil composition; and 
   operating the engine lubricated with the lubricating oil composition.   
     
     
         13 . The method of  claim 12 , wherein the method is effective to reduce low speed pre-ignition events in a boosted internal combustion engine lubricated with the lubricating oil composition relative to a number of low speed pre-ignition events in the same engine lubricated with reference lubricating oil R-1; or the reduction of LSPI events is 50% or greater reduction and the LSPI events are LSPI counts during 25,000 engine cycles, wherein the engine is operated at 2,000 revolutions per minute with brake mean effective pressure of 1,800 kPa,
 wherein R-1 is formulated from about 80.7 wt. % of a Group III base oil, 12.1 wt. % of passenger car motor oil additive package and 7.2 wt. % of a 35 SSI ethylene/propylene copolymer viscosity index improver, wherein the passenger car motor oil additive package is an API SN, ILSAC-GF-5, and ACEA A5/B5 qualified DI package and R-1 also showed the following properties and partial elemental analysis:   
       
         
           
                 
                 
               
                     
                 
                   10.9 
                   Kinematic Viscosity at 100° C., (mm 2 /sec) 
                 
                   3.3 
                   HTHS at 150° C., (cP) 
                 
                   2438 
                   calcium (ppmw) 
                 
                   <10 
                   magnesium (ppmw) 
                 
                   80 
                   molybdenum (ppmw) 
                 
                   772 
                   phosphorus (ppmw) 
                 
                   855 
                   zinc (ppmw) 
                 
                   9.0 
                   Total Base Number ASTM D-2896 (mg KOH/g) 
                 
                   165 
                   Viscosity Index 
                 
                     
                 
             
                
               
               
                
                
                
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         14 . The method of  claim 12 , wherein the one or more overbased calcium-containing detergent(s) has a total base number of greater than 250 mg KOH/g or more as measured by the method of ASTM D-2896. 
     
     
         15 . The method of  claim 12 , wherein the weight ratio of the ppmw of zirconium provided by the zirconium-containing nanoparticles and/or one or more zirconium-containing compound(s) to the ppmw of calcium provided by the one or more overbased calcium-containing detergent(s) is from 0.02 to 4. 
     
     
         16 . The method of  claim 12 , wherein the lubricating oil composition contains greater than 1 ppmw of boron based on the total weight of the lubricating oil composition; or wherein the one or more overbased calcium-containing detergent(s) is present in an amount to provide at least 600 ppmw of calcium to less than 3000 ppmw calcium to the lubricating oil composition, based on the total weight of the lubricating oil composition. 
     
     
         17 . The method of  claim 12 , wherein the zirconium-containing nanoparticles and/or the one or more zirconium-containing compound(s) is present in an amount to provide at least 5 ppmw zirconium to the lubricating oil composition, based on the total weight of the lubricating oil composition. 
     
     
         18 . The method of  claim 12 , further comprising one or more magnesium-containing detergents present in an amount sufficient to provide greater than 500 ppmw to less 1000 ppmw magnesium to the lubricating oil composition, based on the total weight of the lubricating oil composition; or
 wherein the one or more magnesium-containing detergents comprises an overbased magnesium sulfonate detergent having a total base number of greater than 225 mg KOH/g, as measured by the method of ASTM D-2896.   
     
     
         19 . The method of  claim 12 , wherein the one or more zirconium-containing compound(s) is selected from zirconium (IV) oxides, zirconium (IV) sulfides, zirconium (IV) nitrates, zirconium (IV) alkoxides, zirconium phenates, zirconium carboxylates, zirconium salicylates, zirconium sulfonates, zirconium halides, and mixtures thereof; or
 wherein the one or more zirconium-containing compound(s) comprises an organometallic zirconium compound or zirconium nanoparticles.   
     
     
         20 . The method of  claim 12 , wherein the lubricating oil composition is an engine oil composition.