Composition Containing a Block Copolymer and a Method of Lubricating an Internal Combustion Engine

Abstract

The invention provides a lubricating composition containing an oil of lubricating viscosity and a block copolymer. The block copolymer may contain (a) a hydrophobic first block having C 1-30 alkyl (meth)acrylic units, wherein at least 50 wt % of the C 1-30 alkyl (meth)acrylic units are C 12-15 alkyl (meth)acrylic units, and up to 50 wt % of the C 1-30 alkyl (meth)acrylic units are C 16-20 alkyl (meth)acrylic units, with the proviso that alkyl groups of the C 1-30 alkyl (meth)acrylic units have an average total number of carbon atoms of at least 8; and (b) a second block having (meth)acrylic units further having a heteroatom-containing group providing a polar group. The invention further relates to a method of lubricating an internal combustion engine by lubricating the engine with the lubricating composition. The invention further relates to the use of the block copolymer as an emulsifier and/or pour point depressant.

1 - 28 . (canceled) 
     
     
         29 . A method of operating an internal combustion engine of a vehicle fueled with a mixed gasoline/alcohol fuel, comprising supplying to the engine a lubricating composition comprising an oil of lubricating viscosity and a block copolymer having emulsifier properties, wherein the block copolymer comprises a diblock comprising:
 (a) a hydrophobic first block having C 1-30  alkyl (meth)acrylic units, wherein the C 1-30  alkyl (meth)acrylic units comprise C 12-18  alkyl methacrylic units, with the proviso that alkyl groups of the C 1-30  alkyl methacrylic units have an average total number of carbon atoms of at least 8; and   (b) a second block having C 12-18  alkyl methacrylic units which further have a non-carbonyl heteroatom-containing group providing a polar group to such units, the heteroatom-containing group derived from a nitrogen-containing group, whereby said second block exhibits greater hydrophilicity than does the hydrophobic first block,   wherein the mixed gasoline/alcohol fuel contains from 5 wt % to 85 wt % alcohol.   
     
     
         30 . The method of  claim 29 , wherein the block copolymer is present in an amount from about 0.01 wt % to about 0.5 wt % of the lubricating composition. 
     
     
         31 . The method of  claim 29 , wherein the block copolymer is present in an amount from about 0.05 wt % to about 0.3 wt % of the lubricating composition. 
     
     
         32 . The method of  claim 29 , wherein the block copolymer is present in an amount from about 0.01 wt % to about 0.05 wt % of the lubricating composition. 
     
     
         33 . The method of  claim 29 , wherein the internal combustion engine is a flexible fuel vehicle engine. 
     
     
         34 . The method of  claim 29 , wherein at least 50 wt % of the C 12-18  alkyl methacrylic units are C 12-15  alkyl methacrylic units. 
     
     
         35 . The method of  claim 29 , wherein at least 70 wt % of the C 12-18  alkyl methacrylic units are C 12-15  alkyl methacrylic unit. 
     
     
         36 . The method of  claim 29 , wherein at least 80 wt % of the C 12-18  alkyl methacrylic units are C 12-15  alkyl methacrylic units. 
     
     
         39 . The method of  claim 29 , wherein the nitrogen containing group contains a monomer selected from the group consisting of dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, dimethylaminopropyl methacrylate, dimethylaminopropyl acrylate, dimethylaminopropylacrylamide, dimethylaminopropyl-methacrylamide, and mixtures thereof. 
     
     
         40 . The method of claim  6 , wherein the nitrogen-containing monomer is dimethylaminoethyl methacrylate. 
     
     
         41 . The method of  claim 29 , wherein the block copolymer is a methacrylate polymer. 
     
     
         42 . The method of  claim 29 , wherein the block copolymer is a linear diblock copolymer. 
     
     
         43 . The method of  claim 29 , wherein the block copolymer is obtained from a controlled radical polymerisation process or other living polymerisation process. 
     
     
         44 . The method of  claim 43 , wherein the controlled radical or other living polymerisation process is one of RAFT (Reversible Addition Fragmentation Transfer), ATRP (Atom Transfer Radical Polymerisation), nitroxide-mediated or anionic polymerisation. 
     
     
         45 . The method of  claim 44 , wherein the controlled radical polymerisation process is a RAFT process. 
     
     
         46 . The method of  claim 29  wherein the block copolymer has a weight ratio of first block to second block from 1:6 to 1:18. 
     
     
         47 . The method of  claim 29 , wherein the alcohol of the mixed gasoline/alcohol fuel is ethanol. 
     
     
         48 . The method of  claim 29 , wherein the mixed gasoline/alcohol fuel contains from 10 wt % to 85 wt % alcohol. 
     
     
         49 . The method of  claim 29 , wherein the mixed gasoline/alcohol fuel contains from 15 wt % to 85 wt % alcohol.