Lubricating oil compositions for hybrid engines and methods of use and testing thereof

Abstract

This invention relates to a lubricating oil composition for hybrid engines including a) an oil of lubricating viscosity at greater than 50 wt. % of the composition comprising a Group I, II, III or IV base oil, or combinations thereof; b) one or more, optionally borated, higher molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn 1600 g/mol or more); c) optionally one or more, optionally borated, lower molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn less than 1600 g/mol), wherein the treat level of the combination of the higher molecular weight PIBSA-PAM and lower molecular weight PIBSA-PAM is from 1.0 to 12.0 wt. % of the composition, and wherein the treat level of the higher molecular weight PIBSA-PAM is from 1.0 to 9.0 wt. % of the composition; and d) an overbased calcium salicylate or sulfonate detergent, an overbased magnesium salicylate or sulfonate detergent, an overbased mixed calcium and magnesium salicylate or sulfonate detergent or a combination thereof, wherein the detergent has a Total Base Number (KOH/g) greater than or equal to 9 and less than or equal to 500 and delivers at least 5 mmol of total soap to the composition. Also provided is a method of evaluating a lubricating oil composition for ranking its performance in a hybrid engine by running a bench scale test protocol based upon 3 test results: the emulsion dispersion and stability performance at all 4 test conditions in the Emulsion Stability test (modified ASTM D7563), the emulsion corrosion test, and the journal bearing wear test.

What is claimed is: 
     
         1 . A lubricating oil composition for hybrid engines comprising or resulting from the admixing of:
 a) an oil of lubricating viscosity at greater than 50 wt. % of the composition comprising a Group I base oil, a Group II base oil, a Group III base oil, a Group IV base oil, or combinations thereof;   b) one or more, optionally borated, higher molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn 1600 g/mol or more);   c) optionally one or more, optionally borated, lower molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn less than 1600 g/mol), wherein the treat level of the combination of the higher molecular weight PIBSA-PAM and lower molecular weight PIBSA-PAM is from 1.5 to 12.0 wt. % of the lubricating oil composition, and wherein the treat level of the higher molecular weight PIBSA-PAM is from 1.5 to 9.0 wt. % of the lubricating oil composition; and   d) an overbased calcium salicylate detergent, an overbased magnesium salicylate detergent, an overbased mixed calcium and magnesium salicylate detergent or a combination thereof, wherein the detergent has a Total Base Number (KOH/g) greater than or equal to 9 and less than or equal to 500 and delivers at least 5 mmol of total soap to the lubricating oil composition;   wherein the lubricating oil composition has a total sulfated ash of less than or equal to 1.2 wt. %, a kinematic viscosity at 100° C. of 5 to 20 cSt, a total phosphorous level of less than or equal to 0.120 wt. %, and a total sulfur level of less than or equal to 0.4 wt. %; and   wherein the lubricating oil composition results in a passing emulsion dispersion and stability performance at the four test conditions in the Emulsion Stability test (modified ASTM D7563: a) 10%/10% E85/water-24 h; b) 10%/10% E85/water-72 h; c) 15%/15% E85/water-24 h; and d) 15%/15% E85/water-72 h.   
     
     
         2 . The composition of  claim 1 , wherein the lubricating oil composition results in a rating of at least 2 for emulsion corrosion resistance in the emulsion corrosion test; and or the lubricating oil composition results in a rating of at least 2 for bearing wear in the journal bearing wear test. 
     
     
         3 . The composition of  claim 1 , wherein the lubricating oil composition further comprises:
 a) one or more zinc dialkyl dithiophosphate (ZDDP) compounds where the treat level of the one or more ZDDP compounds is from 0.4 wt. % to 2.0 wt. % of the lubricating oil composition; and or   b) one or more corrosion inhibitors, rust inhibitors or combinations thereof at a treat rate of greater than or equal to 0.02 wt. % of the lubricating oil composition where the one or more corrosion and/or rust inhibitors are optionally selected from the group consisting of a non-ionic fatty alcohol ethoxylate, a substituted thiadiazole, a substituted benzotriazole, a substituted triazole, a trisubstituted borate, a primary amine, a substituted carboxylic acid functional group, a substituted ester functional group, a substituted anhydride functional group, or a combination thereof.   
     
     
         4 . The composition of  claim 1 , wherein the composition provides for substantially no aqueous separation of lubricating oil emulsions including the lubricating oil composition and up to 15 wt. % water at 0° C. and 25° C. in the Emulsion stability test (modified ASTM D7563). 
     
     
         5 . The composition of  claim 1 , wherein the higher molecular weight PIBSA-PAM is borated, the optional lower molecular weight PIBSA-PAM is borated or a combination thereof, and is/are included at a treat level to deliver from 20 ppm to 1000 ppm by weight of boron to the composition; and/or wherein the one or more, optionally borated, higher molecular weight PIBSA-PAM dispersant is from 2.0 to 6.0 wt. % of the composition. 
     
     
         6 . The composition of  claim 1 , wherein the oil of lubricating viscosity is at from 60 wt. % to 95 wt. % of the composition, comprises a Group II base oil, a Group III base oil, a Group IV base oil or combinations thereof, and is substantially free of Group I base oil. 
     
     
         7 . The composition of  claim 1 , wherein the soap level is greater than or equal to 0.5 wt. % of the overall composition. 
     
     
         8 . The composition of  claim 1 , further including one or more of the following components: one or more friction modifiers; one or more antioxidants; one or more pour point depressants; one or more anti-foaming agents; one or more viscosity modifiers; one or more dispersants other than the higher molecular weight PIBSA-PAM and the lower molecular weight PIBSA-PAM; one or more inhibitors, one or more antirust agents; one or more seal swell agents; and/or one or more other anti-wear agents. 
     
     
         9 . The composition of  claim 8 , wherein: 1) the one or more antioxidants includes one or more phenolic antioxidants, one or more sulfur based antioxidants, one or more aminic antioxidants or a combination thereof, and wherein the one or more antioxidants comprise from 1.0 to 6.0 wt. % of the composition; and or 2) the one or more friction modifier includes a dimeric molybdenum dialkyldithiocarbamate (moly dimer), a trimeric molybdenum dialkyldithiocarbamate (moly trimer), or a combination thereof at a treat level to deliver from 12 ppm to 1000 ppm by weight of molybdenum to the composition; and or 3) the one or more friction modifier includes an organic friction modifier selected from the group consisting of alkylated succinic anhydrides, alkylated succinic acids, alkylated carboxylic acids, alkoxylated fatty acid esters, alkanolamides, polyol fatty acid esters, borated glycerol fatty acid esters, fatty alcohol ethers, and combinations thereof, wherein the organic friction modifier comprises from 0.01 to 5.0 wt. % of the composition; and or 4) the one or more pour point depressants include polymethacrylate, polyacrylate or a combination thereof, and wherein the one or more pour point depressants comprise from 0.01 to 5.0 wt. % of the composition. 
     
     
         10 . The composition of  claim 1 , wherein the lubricating oil composition is used as a passenger vehicle lubricant (PVL) or a commercial vehicle lubricant (CVL). 
     
     
         11 . A method of lubricating a hybrid engine comprising supplying to the engine a lubricating oil composition of  claim 1 . 
     
     
         12 . A lubricating oil composition for hybrid engines comprising or resulting from the admixing of:
 a) an oil of lubricating viscosity at greater than 50 wt. % of the composition comprising a Group I base oil, a Group II base oil, a Group III base oil, a Group IV base oil, or combinations thereof;   b) one or more, optionally borated, higher molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn 1600 g/mol or more);   c) optionally one or more, optionally borated, lower molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn less than 1600 g/mol), wherein the treat level of the combination of the higher molecular weight PIBSA-PAM and lower molecular weight PIBSA-PAM is from 1.0 to 12.0 wt. % of the composition, and wherein the treat level of the higher molecular weight PIBSA-PAM is from 1.0 (preferably 1.5) to 9.0 wt. % of the composition;   d) an overbased calcium sulfonate detergent, an overbased magnesium sulfonate detergent, an overbased mixed calcium and magnesium sulfonate detergent or a combination thereof, wherein the detergent has a Total Base Number (KOH/g) greater than or equal to 9 and less than or equal to 500 and delivers less than or equal to 5 mmol of total soap to the composition; and   e) one or more organic friction modifier at from 0.01 to 2.0 wt. % of the composition;   wherein the lubricating oil composition has a total sulfated ash of less than or equal to 1.2 wt. %, a kinematic viscosity at 100° C. of 5 to 20 cSt, a total phosphorous level of less than or equal to 0.120 wt. %, and a total sulfur level of less than or equal to 0.4 wt. %; and   wherein the lubricating oil composition results in a rating of at least 2 for emulsion corrosion resistance in the emulsion corrosion test.   
     
     
         13 . The composition of  claim 12 , wherein the lubricating oil composition results in a rating of at least 2 for bearing wear in the journal bearing wear test. 
     
     
         14 . The composition of  claim 12 , wherein the lubricating oil composition further comprises one or more zinc dialkyl dithiophosphate (ZDDP) compounds; and wherein the treat level of the one or more ZDDP compounds is from 0.4 wt. % to 2.0 wt. % of the lubricating oil composition; and or
 b) one or more corrosion inhibitors, rust inhibitors or combinations thereof at a treat rate of greater than or equal to 0.02 wt. % of the lubricating oil composition where the one or more corrosion and/or rust inhibitors are optionally selected from the group consisting of a non-ionic fatty alcohol ethoxylate, a substituted thiadiazole, a substituted benzotriazole, a substituted triazole, a trisubstituted borate, a primary amine, a substituted carboxylic acid functional group, a substituted ester functional group, a substituted anhydride functional group, or a combination thereof.   
     
     
         15 . The composition of  claim 12 , wherein the lubricating oil composition further comprises a functionalized polymer at from 0.01 to 20 wt. %, optionally 0.3 to 5 wt. %, based upon the total weight of the lubricating oil composition, wherein the functionalized polymer comprises a partially or fully saturated olefin homopolymer or copolymer backbone and at least one functional group:
 i) having an Mn of 10,000 g/mol or more (GPC-PS) of the polymer prior to functionalization,   ii) where the functional group is derived from an acylating agent and a compound containing amino and/or hydroxyl groups (including but not limited to where the polymer is functionalized with an acylating agent and subsequently reacted with a compound containing amino and/or hydroxyl groups), and   iii) wherein the homopolymer or copolymer backbone is derived from monomers selected from the group consisting of C 2  to C 30  linear alpha olefins, and C 4  to C 20  conjugated dienes;   
       wherein the functionalized polymer comprises an amide, imide, and/or ester functionalized partially or fully saturated polymer comprising C 4-5  olefins having:
 i) an Mw/Mn of less than 2, 
 ii) a Functionality Distribution (Fd) value of 3.5 or less, and 
 iii) an Mn of 10,000 g/mol or more (GPC-PS) of the polymer prior to functionalization, provided that, if the polymer prior to functionalization is a copolymer of isoprene and butadiene, then the Mn of the copolymer is greater than 25,000 g/mol (GPC-PS). 
 
     
     
         16 . The composition of  claim 12 , wherein the composition provides for substantially no aqueous separation of lubricating oil emulsions including the lubricating oil composition and up to 15 wt. % water at 0° C. and 25° C. in the Emulsion Stability test (modified ASTM D7563). 
     
     
         17 . The composition of  claim 12 , wherein the higher molecular weight PIBSA-PAM is borated, the optional lower molecular weight PIBSA-PAM is borated or a combination thereof, and is/are included at a treat level to deliver from 20 ppm to 600 ppm by weight of boron to the composition, and or wherein the one or more, optionally borated, higher molecular weight PIBSA-PAM dispersant is from 2.0 to 4.5 wt. % of the composition. 
     
     
         18 . The composition of  claim 12 , wherein the oil of lubricating viscosity is at from 60 wt. % to 95 wt. % of the composition, comprises a Group II base oil, a Group III base oil, a Group IV base oil or combinations thereof, and is substantially free of Group I base oil. 
     
     
         19 . The composition of  claim 12 , wherein the detergent includes a combination of an overbased calcium salicylate detergent and an overbased magnesium salicylate detergent. 
     
     
         20 . The composition of  claim 12 , further including one or more of the following components: one or more other friction modifiers; one or more antioxidants; one or more pour point depressants; one or more anti-foaming agents; one or more viscosity modifiers; one or more dispersants other than the higher molecular weight PIBSA-PAM and the lower molecular weight PIBSA-PAM; one or more inhibitors, one or more antirust agents; one or more seal swell agents; and/or one or more other anti-wear agents. 
     
     
         21 . The composition of  claim 20 , wherein the one or more antioxidants includes one or more phenolic antioxidants, one or more sulfur based antioxidants, one or more aminic antioxidants or a combination thereof, and wherein the one or more antioxidants comprise from 1.0 to 6.0 wt. % of the composition; and or wherein the one or more other friction modifier includes a dimeric molybdenum dialkyldithiocarbamate (moly dimer), a trimeric molybdenum dialkyldithiocarbamate (moly trimer), or a combination thereof at a treat level to deliver from 12 ppm to 1000 ppm by weight of molybdenum to the composition; and or wherein the one or more organic friction modifier is selected from the group consisting of alkylated succinic anhydrides, alkylated succinic acids, alkylated carboxylic acids, alkoxylated fatty acid esters, alkanolamides, polyol fatty acid esters, borated glycerol fatty acid esters, fatty alcohol ethers, and combinations thereof; and or wherein the one or more pour point depressants include polymethacrylate, polyacrylate or a combination thereof, and wherein the one or more pour point depressants comprise from 0.01 to 5.0 wt. % of the composition. 
     
     
         22 . The composition of  claim 12 , wherein the lubricating oil composition is used as a passenger vehicle lubricant (PVL) or a commercial vehicle lubricant (CVL). 
     
     
         23 . A method of lubricating a hybrid engine comprising supplying to the engine a lubricating oil composition of  claim 12 . 
     
     
         24 . A concentrate comprising or resulting from the admixing of:
 from 1 to less than or equal to 50 wt. % of one or more base oils;   from 2 to 40 wt. % of an overbased calcium salicylate detergent, an overbased magnesium salicylate detergent, an overbased mixed calcium and magnesium salicylate detergent or a combination thereof, wherein the detergent has a Total Base Number (KOH/g) greater than or equal to 9 and less than or equal to 500; and   from 2 to 40 wt. % of one or more, optionally borated, higher molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn 1600 g/mol or more), and one or more, optionally borated, lower molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn less than 1600 g/mol).   
     
     
         25 . The concentrate of  claim 24 , further including: 1) from 2 to 20 wt. % of one or more zinc hydrocarbyl diphosphate compounds, wherein the one or more zinc hydrocarbyl diphosphate compounds include hydrocarbyl groups derived from one or more primary alcohols, one or more secondary alcohols or a combination of primary and secondary alcohols; and or 2) from 0.10 to 10 wt. % of one or more corrosion inhibitors, rust inhibitors or combinations thereof selected from the group consisting of a non-ionic fatty alcohol ethoxylate, a substituted thiadiazole, a substituted benzotriazole, a substituted triazole, a trisubstituted borate, a primary amine, a substituted carboxylic acid functional group, a substituted ester functional group, a substituted anhydride functional group or a combination thereof; and or 3) from 1 to 30 wt. %, such as 2 to 20 wt. %, based upon the weight of the concentrate, of one or more functionalized polymers, wherein the one or more functionalized polymers comprise a partially or fully saturated olefin homopolymer or copolymer backbone and at least one functional group, having:
 i) an Mn of 10,000 g/mol or more (GPC-PS) of the polymer prior to functionalization, 
 ii) where the functional group is derived from an acylating agent and a compound containing amino and/or hydroxyl groups (including but not limited to where the polymer is functionalized with an acylating agent and subsequently reacted with a compound containing amino and/or hydroxyl groups), and, 
 iii) wherein the homopolymer or copolymer backbone is derived from monomers selected from the group consisting of C 2  to C 30  linear alpha olefins, and C 4  to C 20  conjugated dienes; 
 
     
     
         26 . The concentrate of  claim 24 , further comprising combining the concentrate with a base oil to form a lubricating oil composition comprising:
 a) an oil of lubricating viscosity at greater than 50 wt. % of the composition comprising a Group II base oil, a Group III base oil, a Group IV base oil, or combinations thereof;   b) one or more, optionally borated, higher molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn 1600 g/mol or more);   c) optionally one or more, optionally borated, lower molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn less than 1600 g/mol), wherein the treat level of the combination of the higher molecular weight PIBSA-PAM and lower molecular weight PIBSA-PAM is from 1.0 to 12.0 wt. % of the composition, and wherein the treat level of the higher molecular weight PIBSA-PAM is from 1.0 to 9.0 wt. % of the composition; and   d) an overbased calcium salicylate detergent, an overbased magnesium salicylate detergent, an overbased mixed calcium and magnesium salicylate detergent or a combination thereof, wherein the detergent has a Total Base Number (KOH/g) greater than or equal to 9 and less than or equal to 500 and delivers at least 5 mmol of total soap to the composition;   wherein the lubricating oil composition has a total sulfated ash of less than or equal to 1.2 wt. %, a kinematic viscosity at 100° C. of 5 to 20 cSt, a total phosphorous level of less than or equal to 0.120 wt. %, and a total sulfur level of less than or equal to 0.4 wt. %; and   wherein the lubricating oil composition results in a passing emulsion stability performance at all 4 test conditions in the Emulsion Stability test (modified ASTM D7563).   
     
     
         27 . A concentrate comprising or resulting from the admixing of:
 from 1 to less than or equal to 50 wt. % of one or more base oils;   from 2 to 40 wt. % of an overbased calcium sulfonate detergent, an overbased magnesium sulfonate detergent, an overbased mixed calcium and magnesium sulfonate detergent or a combination thereof, wherein the detergent has a Total Base Number (KOH/g) greater than or equal to 9 and less than or equal to 500;   from 2 to 40 wt. % of one or more, optionally borated, higher molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn 1600 g/mol or more), and one or more, optionally borated, lower molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn less than 1600 g/mol); and   from 0.5 to 10 wt. % of one or more organic friction modifier.   
     
     
         28 . The concentrate of  claim 27 , further including:
 from 2 to 20 wt. % of one or more zinc hydrocarbyl diphosphate compounds, wherein the one or more zinc hydrocarbyl diphosphate compounds include hydrocarbyl groups derived from one or more primary alcohols, one or more secondary alcohols or a combination of primary and secondary alcohols;   and or from 0.10 to 10 wt. % of one or more corrosion inhibitors, rust inhibitors or combinations thereof selected from the group consisting of a non-ionic fatty alcohol ethoxylate, a substituted thiadiazole, a substituted benzotriazole, a substituted triazole, a trisubstituted borate, a primary amine, a substituted carboxylic acid functional group, a substituted ester functional group, a substituted anhydride functional group or a combination thereof; and or   more functionalized polymers, wherein the one or more functionalized polymers comprise a partially or fully saturated olefin homopolymer or copolymer backbone and at least one functional group, having:
 i) an Mn of 10,000 g/mol or more (GPC-PS) of the polymer prior to functionalization, 
 ii) where the functional group is derived from an acylating agent and a compound containing amino and/or hydroxyl groups (including but not limited to where the polymer is functionalized with an acylating agent and subsequently reacted with a compound containing amino and/or hydroxyl groups), and, 
 iii) wherein the homopolymer or copolymer backbone is derived from monomers selected from the group consisting of C2 to C30 linear alpha olefins, and C4 to C20 conjugated dienes; 
   
     
     
         29 . The concentrate of  claim 27 , further comprising combining the concentrate with a base oil to form a lubricating oil composition comprising:
 a) an oil of lubricating viscosity at greater than 50 wt. % of the composition comprising a Group II base oil, a Group III base oil, a Group IV base oil, or combinations thereof;   b) one or more, optionally borated, higher molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn 1600 g/mol or more),   c) optionally one or more, optionally borated, lower molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersant (Mn less than 1600 g/mol), wherein the treat level of the combination of the higher molecular weight PIBSA-PAM and lower molecular weight PIBSA-PAM is from 1.0 (preferably 1.5) to 12.0 wt. % of the composition, and wherein the treat level of the higher molecular weight PIBSA-PAM is from 1.0 to 9.0 wt. % of the composition;   d) an overbased calcium sulfonate detergent, an overbased magnesium sulfonate detergent, an overbased mixed calcium and magnesium sulfonate detergent or a combination thereof, wherein the detergent has a Total Base Number (KOH/g) greater than or equal to 9 and less than or equal to 500 and delivers less than or equal to 5 mmol of total soap to the composition; and   e) one or more organic friction modifier at from 0.01 to 2.0 wt. % of the composition;   wherein the lubricating oil composition has a total sulfated ash of less than or equal to 1.2 wt. %, a kinematic viscosity at 100° C. of 5 to 20 cSt, a total phosphorous level of less than or equal to 0.120 wt. %, and a total sulfur level of less than or equal to 0.4 wt. %; and   wherein the lubricating oil composition results in a rating of at least 2 for emulsion corrosion resistance in the emulsion corrosion test.   
     
     
         30 . A method of evaluating a lubricating oil composition for ranking performance of the lubricating oil composition in a hybrid engine comprising the steps of:
 i) selecting a lubricating oil composition for bench scale testing;   ii) testing the composition for emulsion dispersion and stability performance in the Emulsion Stability test (modified ASTM D7563) to determine its score from 0 to 3;   iii) testing the composition for emulsion corrosion resistance in the emulsion corrosion test to determine its score from 0 to 3;   iv) testing the composition for journal bearing wear in the journal bearing wear test to determine the change in the depth of the bearing pre-test and post-test in average maximum wear and assigning a wear result from 1 to 3; and   v) combining test results from steps ii), iii) and iv) above to provide an overall performance rating for ranking the performance of the lubricating oil composition in a hybrid engine.