Lubricating composition

Abstract

A lubricating composition for use in the crankcase of an engine comprising (i) a base oil; (ii) one or more organo-molybdenum compounds at a level sufficient to provide from 100 to 1000 ppmw of molybdenum; and (iii) from 0.2 wt % to 5.0 wt %, by weight of the lubricating composition, of one or more organic polymeric friction reducing additives, wherein the one or more organic polymeric friction reducing additives has a molecular weight ranging from 1000 to 30000 Daltons and is the reaction product of: a) a hydrophobic polymeric sub unit which comprises a hydrophobic polymer selected from polyolefins, polyacrylics and polystyrenyls; b) a hydrophilic polymeric sub unit which comprises a hydrophilic polymer selected from polyethers, polyesters, polyamides; c) optionally at least one backbone moiety capable of linking together polymeric sub units; and d) optionally a chain terminating group. The lubricating composition provides improvements in terms of reduced friction and wear, in addition to improved fuel economy performance.

1 . A lubricating composition for use in the crankcase of an engine comprising (i) a base oil; (ii) one or more organo-molybdenum compounds at a level sufficient to provide from 100 to 1000 ppmw of molybdenum; and (iii) from 0.2 wt % to 5.0 wt %, by weight of the lubricating composition, of one or more organic polymeric friction reducing additives, wherein the one or more organic polymeric friction reducing additives has a molecular weight ranging from 1000 to 30000 Daltons and is the reaction product of:
 a) a hydrophobic polymeric sub unit which comprises a hydrophobic polymer selected from polyolefins, polyacrylics and polystyrenyls;   b) a hydrophilic polymeric sub unit which comprises a hydrophilic polymer selected from polyethers, polyesters, polyamides;   c) optionally at least one backbone moiety capable of linking together polymeric sub units; and   d) optionally a chain terminating group.   
     
     
         2 . A lubricating composition according to  claim 1  wherein the one or more organic polymeric friction reducing additives is the reaction product of:
 a) a hydrophobic polymeric sub unit which comprises a hydrophobic polymer selected from polyolefins, polyacrylics and polystyrenyls; 
 b) a hydrophilic polymeric sub unit which comprises a hydrophilic polymer selected from polyethers, polyesters, polyamides; 
 c) at least one backbone moiety capable of linking together polymeric sub units; and 
 d) a chain terminating group. 
 
     
     
         3 . A lubricating composition according to  claim 1  wherein the one or more organic polymeric friction reducing additives is the reaction product of:
 a) a hydrophobic polymeric sub unit which comprises a hydrophobic polymer selected from polyolefins, polyacrylics and polystyrenyls; 
 b) a hydrophilic polymeric sub unit which comprises a hydrophilic polymer selected from polyethers, polyesters, polyamides; and 
 c) at least one backbone moiety capable of linking together polymeric sub units. 
 
     
     
         4 . A lubricating composition according to  claim 1  wherein the one or more organic polymeric friction reducing additives is the reaction product of:
 a) a hydrophobic polymeric sub unit which comprises a hydrophobic polymer selected from polyolefins, polyacrylics and polystyrenyls; 
 b) a hydrophilic polymeric sub unit which comprises a hydrophilic polymer selected from polyethers, polyesters, polyamides; and 
 d) a chain terminating group. 
 
     
     
         5 . A lubricating composition according to  claim 1  wherein the hydrophobic polymeric sub unit comprises a hydrophobic polymer which is a polyolefin. 
     
     
         6 . A lubricating composition according to  claim 1  wherein the hydrophobic polymeric sub unit comprises polyisobutylene polymer which has been subjected to maleinisation to form polyisobutylene succinic anhydride having a molecular weight in the range of 300 to 5000 Daltons. 
     
     
         7 . A lubricating composition according to  claim 1  wherein the hydrophilic polymeric sub unit comprises a hydrophilic polymer which is a polyethylene glycol. 
     
     
         8 . A lubricating composition according to  claim 1  wherein the backbone moiety is chosen from a polyol, a polycarboxylic acid and mixtures thereof. 
     
     
         9 . A lubricating composition according to  claim 1  wherein the chain terminating group is any fatty carboxylic acid. 
     
     
         10 . A lubricating composition according to  claim 1  wherein the reaction product comprises some block copolymer units formed from linking together during the reaction of some of the hydrophobic and hydrophilic polymeric sub units. 
     
     
         11 . A lubricating composition according to  claim 10  wherein the number of block copolymer units range from 1 to 20. 
     
     
         12 . A lubricating composition according to  claim 1  wherein the one or more organo-molybdenum compounds is selected from molybdenum dithiocarbamates (MoDTC), molybdenum dithiophosphates (MoDTP), molybdenum amines, molybdenum alcoholates, and molybdenum alcohol-amides, and mixtures thereof. 
     
     
         13 . A lubricating composition according to  claim 12  wherein the one or more organo-molybdenum compounds is a molybdenum dithiocarbamate (MoDTC). 
     
     
         14 . A lubricating composition according to  claim 1  additionally comprising a hydroxy alkyl amine 
     
     
         15 . A lubricating composition according to  claim 1  wherein the base oil is a Fischer-Tropsch derived base oil. 
     
     
         16 . (canceled) 
     
     
         17 . (canceled) 
     
     
         18 . (canceled) 
     
     
         19 . A method of lubricating an internal combustion engine comprising:
 applying a lubricating composition to a surface in a crankcase of the engine, wherein the lubricating composition comprises (i) a base oil; (ii) one or more organo-molybdenum compounds at a level sufficient to provide from 100 to 1000 ppmw of molybdenum; and (iii) from 0.2 wt % to 5.0 wt %, by weight of the lubricating composition, of one or more organic polymeric friction reducing additives, wherein the one or more organic polymeric friction reducing additives has a molecular weight ranging from 1000 to 30000 Daltons and is the reaction product of:   a) a hydrophobic polymeric sub unit which comprises a hydrophobic polymer selected from polyolefins, polyacrylics and polystyrenyls;   b) a hydrophilic polymeric sub unit which comprises a hydrophilic polymer selected from polyethers, polyesters, polyamides;   c) optionally at least one backbone moiety capable of linking together polymeric sub units; and   d) optionally a chain terminating group.   
     
     
         20 . A method according to  claim 19  wherein the one or more organic polymeric friction reducing additives is the reaction product of:
 a) a hydrophobic polymeric sub unit which comprises a hydrophobic polymer selected from polyolefins, polyacrylics and polystyrenyls; 
 b) a hydrophilic polymeric sub unit which comprises a hydrophilic polymer selected from polyethers, polyesters, polyamides; 
 c) at least one backbone moiety capable of linking together polymeric sub units; and 
 d) a chain terminating group. 
 
     
     
         21 . A method according to  claim 19  wherein the one or more organic polymeric friction reducing additives is the reaction product of:
 a) a hydrophobic polymeric sub unit which comprises a hydrophobic polymer selected from polyolefins, polyacrylics and polystyrenyls; 
 b) a hydrophilic polymeric sub unit which comprises a hydrophilic polymer selected from polyethers, polyesters, polyamides; and 
 c) at least one backbone moiety capable of linking together polymeric sub units. 
 
     
     
         22 . A method according to  claim 19  wherein the one or more organic polymeric friction reducing additives is the reaction product of:
 a) a hydrophobic polymeric sub unit which comprises a hydrophobic polymer selected from polyolefins, polyacrylics and polystyrenyls; 
 b) a hydrophilic polymeric sub unit which comprises a hydrophilic polymer selected from polyethers, polyesters, polyamides; and 
 a chain terminating group.