Formulating with functional polymers for improved retained fuel economy performance

Abstract

Lubricating oil compositions are disclosed that are suitable for use in all engine types and that provide a reduced Average Friction/Traction coefficient in use, with attendant improvement in fuel economy performance, especially retained fuel economy performance. The disclosed compositions are also advantageous in that molybdenum-based friction modifying ingredients previously considered crucial to reducing friction from metal-metal contact and high molecular weight PIBSA-PAM dispersants can be omitted or used at lower treat rates without impairing friction-reducing or fuel economy performance.

What is claimed is: 
     
         1 . A lubricating oil composition comprising:
 (A) at least 50 mass % or more of one or more base oils, based on the total mass of the lubricating oil composition; and   (B) 0.01 to 20 mass % based upon the total mass of the lubricating oil composition, of a functionalized polymer comprising:
 (B1) a partially or fully saturated olefin homopolymer or copolymer backbone and at least one functional group:
 the backbone having a Mn of 10,000 g/mol or more, as measured by gel permeation chromatography using a polystyrene standard (GPC-PS), prior to functionalization, 
 the functional group being derived from an acylating agent and a compound containing amino and/or hydroxyl groups, and, 
 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, 
 
 or 
 (B2) an amide, imide, and/or ester functionalized partially or fully saturated polymer comprising C 4-5  olefins having:
 an Mw/Mn of less than 2, 
 a Functionality Distribution (Fd) value of 3.5 or less, and an Mn of 10,000 g/mol or more, as measured by Gel Permeation Chromatography using PolyStyrene as a standard (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), 
 
 or a mixture of B1 and B2; and 
   C) a detergent; and   
       the lubricating oil composition has an Average Friction/Traction coefficient of 0.174 or less as determined by High Frequency Reciprocating Rig (HFRR) test. 
     
     
         2 . The lubricating oil composition of  claim 1 , that is substantially free of an organic friction modifying ingredient. 
     
     
         3 . The lubricating oil composition of  claim 1 , further including an organic friction modifying ingredient comprising a fatty acid ester. 
     
     
         4 . The lubricating oil composition of  claim 1 , that includes a molybdenum-based friction modifying ingredient at 150 ppm or less of molybdenum. 
     
     
         5 . The lubricating oil composition of  claim 1  that further comprises a molybdenum-based friction modifying ingredient. 
     
     
         6 . The lubricating oil composition of  claim 1 , wherein the functionalized polymer is the polymer (B1). 
     
     
         7 . The lubricating oil composition of  claim 1 , wherein the functionalized polymer is the polymer (B2). 
     
     
         8 . The lubricating oil composition of  claim 1 , wherein the functionalized polymer is a mixture of (B1) and (B2). 
     
     
         9 . The lubricating oil composition of  claim 1 , comprising or resulting from the admixing of:
 (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) a functionalized polymer at from 0.1 to 20 wt. %, of the composition that is:
 (B1) a partially or fully saturated olefin homopolymer or copolymer backbone and at least one functional group:
 the backbone having a Mn of 10,000 g/mol or more, as measured by gel permeation chromatography using a polystyrene standard (GPC-PS), prior to functionalization, 
 the functional group being derived from an acylating agent and a compound containing amino and/or hydroxyl groups, and, 
 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; 
 
 or 
 (B2) comprising an amide, imide, and/or ester functionalized partially or fully saturated polymer comprising C 4-5  olefins having:
 iii) an Mw/Mn of less than 2, 
 iv) 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), 
 
   or a mixture of (B1) and (B2);   (C) an overbased calcium based detergent with a Total Base Number (KOH/g) greater than or equal to 9 and less than or equal to 500 and at treat level to deliver at least 500 ppm by weight of calcium to the composition;   (D) an overbased magnesium based detergent with a Total Base Number (KOH/g) greater than or equal to 9 and less than or equal to 500 and at treat level to deliver at least 200 ppm by weight of magnesium to the composition;   (E) optionally, one or more, optionally borated, higher molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersants having a Mn 1600 g/mol or more (alternately 2000 g/mol or more, alternately 2200 g/mol or more), and   (F) optionally, one or more, optionally borated, lower molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersants having a Mn less than 1600 g/mol (alternately less than 1200 g/mol, alternately less than 1000 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 6.0 wt. % of the composition, and wherein the treat level of the higher molecular weight PIBSA-PAM is less than or equal to 4.0 wt. % of the composition;   
       wherein the molecular weight of the PIBSA-PAM (E) and PIBSA-PAM (F) is measured by gel permeation chromatography using a polystyrene standard (GPC-PS);
 the lubricating oil composition having a total sulfated ash of less than or equal to 0.9 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 0.35 wt. %; 
 
       wherein the wt % is based on the total mass of the composition; and 
       the lubricating oil composition optionally has an Average Friction/Traction coefficient of 0.170 or less as determined by High Frequency Reciprocating Rig (HFRR) test. 
     
     
         10 . The lubricating oil composition of  claim 9 , comprising the higher molecular weight PIBSA-PAM and the lower molecular weight PIBSA-PAM and wherein the lower molecular weight PIBSA-PAM is borated and included at a treat level to deliver from 20 ppm to 700 ppm by weight of boron to the composition. 
     
     
         11 . The lubricating oil composition of  claim 9 , that omits the higher molecular weight PIBSA-PAM (E). 
     
     
         12 . The lubricating oil composition of  claim 9 , wherein the overbased magnesium based detergent is a sulfonate, a salicylate, a phenate or a combination of any two or more of them. 
     
     
         13 . The lubricating oil composition of  claim 9 , wherein the overbased calcium based detergent is a sulfonate, a salicylate, a phenate or a combination of any two or more of them. 
     
     
         14 . The lubricating oil composition of  claim 9 , further including one or more of the following components: 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 anti-wear agents. 
     
     
         15 . The lubricating oil composition of  claim 14 , wherein the one or more anti-wear agents includes one or more zinc dialkyldithiophosphates (ZDDP) at a treat level to deliver less than or equal to 0.12% by weight of phosphorous to the composition. 
     
     
         16 . The lubricating oil composition of  claim 14 , 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. 
     
     
         17 . The lubricating oil composition of  claim 1 , wherein the functionalized polymer comprises a partially or fully saturated homopolyisoprene containing one or more pendant amine groups and having an Mn of 25,000 to 100,000 g/mol (GPC-PS) and at least 50% of 1,4-insertions of monomer. 
     
     
         18 . The lubricating oil composition of  claim 9 , wherein the functionalized polymer comprises a partially or fully saturated homopolyisoprene containing one or more pendant amine groups and having an Mn of 25,000 to 100,000 g/mol (GPC-PS) and at least 50% of 1,4-insertions prior to functionalization. 
     
     
         19 . The lubricating oil composition of any  claim 9 , wherein styrene repeat units are absent in the functionalized polymer and/or butadiene repeat units are absent in the functionalized polymer and/or the functionalized polymer is not homo-polyisobutylene and/or is not a copolymer of isoprene and butadiene. 
     
     
         20 . A lubricating oil composition 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, Group II base oil, a Group III base oil, a Group IV base oil, or combinations thereof;   (B) a functionalized polymer at from 0.1 to 20 wt. %, alternately 0.2 to 2.0 wt. %, of the composition comprising 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 (GPC-PS) 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);   (C) an overbased calcium based detergent with a Total Base Number (KOH/g) greater than or equal to 9 and less than or equal to 500 and at treat level to deliver at least 500 ppm by weight of calcium to the composition;   (D) an overbased magnesium based detergent with a Total Base Number (KOH/g) greater than or equal to 9 and less than or equal to 500 and at treat level to deliver at least 200 ppm by weight of magnesium to the composition;   (E) optionally one or more, optionally borated, higher molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersants having Mn 1600 g/mol or more, and   (F) one or more, optionally borated, lower molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersants having 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 6.0 wt. % of the composition, and wherein the treat level of the higher molecular weight PIBSA-PAM is less than or equal to 4.0 wt. % of the composition;   the lubricating oil composition having a total sulfated ash of less than or equal to 0.9 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 0.35 wt. %, and   wherein the lubricating oil composition provides an Average Friction/Traction coefficient of 0.170 or less in a HFRR test.   
     
     
         21 . The lubricating oil composition of  claim 20 , wherein the functionalized polymer is present at from 0.3 to 5 wt. %. 
     
     
         22 . The lubricating oil composition of  claim 20 , wherein the lubricating oil composition is a heavy-duty diesel oil, a light-duty diesel oil, a hydrogen engine oil, a spark ignition combustion engine oil or a natural gas engine oil. 
     
     
         23 . The lubricating composition of  claim 20 , wherein the lubricating oil composition exhibits an SAE viscosity grade of 20W-X, 15W-X, 10W-X, 5W-X, or 0W-X, where X represents any one of 8, 12, 16, 20, 30, 40, and 50. 
     
     
         24 . A concentrate comprising or resulting from the admixing of:
 (A) from 1 to less than or equal to 50 wt. % of one or more base oils; and   (B) from 1 to 30 wt. %, such as 2 to 20 wt. %, based upon the weight of the concentrate, of:
 (B1) a partially or fully saturated olefin homopolymer or copolymer backbone and at least one functional group:
 the backbone having a Mn of 10,000 g/mol or more, as measured by gel permeation chromatography using a polystyrene standard (GPC-PS), prior to functionalization, 
 the functional group being derived from an acylating agent and a compound containing amino and/or hydroxyl groups and, 
 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; or 
 
 (B2) one or more of the functionalized polymers of the composition comprising an amide, imide, and/or ester functionalized partially or fully saturated polymer comprising C 4-5  olefins having:
 iv) an Mw/Mn of less than 2, 
 v) a Functionality Distribution (Fd) value of 3.5 or less, and 
 vi) 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), 
 
 or a mixture of (B1) and (B2); 
   (C) from 2 to 20 wt. % of an overbased magnesium based detergent with a Total Base Number (KOH/g) greater than or equal to 9 and less than or equal to 500;   (F) from 2 to 20 wt. % of an overbased calcium based detergent with a Total Base Number (KOH/g) greater than or equal to 9 and less than or equal to 500; and   (G) optionally, 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/or one or more, optionally borated, lower molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersants (Mn less than 1600 g/mol); wherein the wt % is based upon the total weight of the concentrate.   
     
     
         25 . A method of making a lubricating oil composition comprising combining:
 (1) 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;   (2A) a partially or fully saturated olefin homopolymer or copolymer backbone and at least one functional group:
 the backbone having a Mn of 10,000 g/mol or more, as measured by gel permeation chromatography using a polystyrene standard (GPC-PS), prior to functionalization, 
 the functional group being derived from an acylating agent and a compound containing amino and/or hydroxyl groups, and, 
 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; or 
   (2B) a functionalized polymer at from 0.1 to 20 wt. %, such as 0.2 to 2.0 wt. %, of the composition comprising 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 
 iv) an Mn of 10,000 g/mol or more (GPC-PS) of the polymer prior to functionalization, 
   
       or both of (2A) and (2B); 
       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). 
     
     
         26 . The method of  claim 25 , further comprising combining into the composition friction modifying ingredient, optionally comprising fatty acid ester and or molybdenum-based friction modifying ingredient providing 150 ppm or less of molybdenum to the lubricating oil composition. 
     
     
         27 . The method of  claim 25 , further comprising combining into the composition:
 (3) an overbased calcium based detergent with a Total Base Number (KOH/g) greater than or equal to 9 and less than or equal to 500 and at treat level to deliver at least 500 ppm by weight of calcium to the composition;   (4) an overbased magnesium based detergent with a Total Base Number (KOH/g) greater than or equal to 9 and less than or equal to 500 and at treat level to deliver at least 200 ppm by weight of magnesium to the composition;   (5) optionally, one or more, optionally borated, higher molecular weight polyisobutylene succinimide (PIBSA-PAM) dispersants (Mn 1600 g/mol or more), and   (6) 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 6.0 wt. % of the composition, and wherein the treat level of the higher molecular weight PIBSA-PAM is less than or equal to 4.0 wt. % of the composition.   
     
     
         29 . The method of  claim 27 , wherein the higher molecular weight PIBSA-PAM is borated, the lower molecular weight PIBSA-PAM is borated or both of the higher molecular weight and lower molecular weight PIBSA-PAM are borated, and is/are included at a treat level to deliver from 20 ppm to 700 ppm by weight of boron to the composition. 
     
     
         30 . The method of  claim 27 , in which the higher molecular weight PIBSA-PAM (5) is not combined. 
     
     
         31 . The method of  claim 27 , wherein the oil of lubricating viscosity is at from 60 wt. % to 95 wt. % of the composition, and is a Group III base oil. 
     
     
         32 . The method of  claim 27 , wherein the overbased magnesium based detergent is a sulfonate, a salicylate, a phenate or combinations thereof and the overbased calcium based detergent is a sulfonate, a salicylate, a phenate or a combination of any two or more of them. 
     
     
         33 . The method of  claim 27 , further including combining one or more of the following components: 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 anti-wear agents. 
     
     
         34 . The method of  claim 33 , wherein: 1) the one or more anti-wear agents includes one or more zinc dialkyldithiophosphates (ZDDP) at a treat level to deliver less than or equal to 0.12% by weight of phosphorous to the composition; and 2) 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 the one or more antioxidants comprise from 1.0 to 6.0 wt. % of the composition; and 3) the functionalized polymer comprises a partially or fully saturated homopolyisoprene containing one or more pendant amine groups and having an Mn of 25,000 to 100,000 g/mol (GPC-PS) and at least 50% of 1,4-insertions prior to functionalization. 
     
     
         35 . The method of  claim 34 , wherein styrene repeat units are absent in the functionalized polymer, and butadiene repeat units are absent in the functionalized polymer, and the functionalized polymer is not homo-polyisobutylene, and the functionalized polymer is not a copolymer of isoprene and butadiene. 
     
     
         36 . The method of  claim 35 , wherein the resulting lubricating oil composition is a heavy-duty diesel oil, a light-duty diesel oil, a hydrogen engine oil, a spark ignition combustion engine oil or a natural gas engine oil. 
     
     
         37 . The method of  claim 34 , wherein the resulting lubricating oil composition exhibits an SAE viscosity grade of 20W-X, 15W-X, 10W-X, 5W-X, or 0W-X, where X represents any one of 8, 12, 16, 20, 30, 40, and 50. 
     
     
         38 . A method of lubricating an engine, improving fuel economy of an engine and or reducing an Average Friction/Traction Coefficient of an engine comprising supplying to the engine a lubricating oil composition according to  claim 20 . 
     
     
         39 . The method of  claim 38 , further including providing a natural gas, hydrogen, gasoline or diesel fuel to the engine and combusting the fuel in the engine. 
     
     
         40 . The lubricating composition of  claim 20 , wherein the functionalized polymer of the composition comprising an amide, imide, and/or ester functionalized partially or fully saturated polymer comprising C 4-5  olefins has a Functionality Distribution (Fd) value of 1.7 to 3.5, alternately 1.7 to 1.9. 
     
     
         41 . The lubricating oil composition of  claim 1  wherein the lubrication oil composition comprises a molybdenum-based friction modifying ingredient and provides a relative torque reduction of 2 percent or more (as compared to reference oil 2 in Table 4 below when measured at 105° C., 1100 rpm using the Motored Friction Rig test described in the Experimental section) and optionally where PIBSA-PAM having an Mn of 1600 g/mol or more is absent and optionally organic friction modifier, such as glycerol monooleate, is absent.