Lubricating oil composition

Abstract

A method of reducing deposits in an internal combustion engine, comprising lubricating the internal combustion engine with a lubricating oil composition comprising lubricating oil base oil, one or more anti-wear additives and one or more poly(hydroxycarboxylic acid) amide salt derivatives preparable by reaction of an amine and a poly(hydroxycarboxylic acid) of formula (I) Y—CO[O-A-CO] n —OH   (I) where Y is hydrogen or optionally substituted hydrocarbyl group, A is a divalent optionally substituted hydrocarbyl group and n is from 1 to 100, with an acid or a quaternizing agent.

1 . A method of reducing deposits in an internal combustion engine, comprising: 
 lubricating the internal combustion engine with a lubricating oil composition comprising lubricating oil base oil, at least one anti-wear additive, and at least one poly(hydroxycarboxylic acid) amide salt derivative preparable by reaction of an amine and a poly(hydroxycarboxylic acid) of formula (I)      Y—CO[O-A-CO] n —OH   (I)    where Y is hydrogen or optionally substituted hydrocarbyl group, A is a divalent optionally substituted hydrocarbyl group and n is from 1 to 100, with an acid or a quaternizing agent.    
   
   
       2 . The method according to  claim 1  wherein the poly(hydroxycarboxylic acid) amide salt derivatives comprises a compound of formula (III)  
       [Y—CO[O-A-CO] n -Z-R + ] m  pX q−   (III)  
     wherein Y is hydrogen or optionally substituted hydrocarbyl group, A is a divalent optionally substituted hydrocarbyl group, n is from 1 to 100, m is from 1 to 4, q is from 1 to 4 and p is an integer such that pq=m, Z is an optionally substituted divalent bridging group which is attached to the carbonyl group through a nitrogen atom, R +  is an ammonium group and X q−  is an anion.  
   
   
       3 . The method according to  claim 2  wherein R +  is a quaternary ammonium group.  
   
   
       4 . The method according to  claim 2  wherein A is selected from the group consisting of arylene, alkylene, and alkenylene groups.  
   
   
       5 . The method according to  claim 2  wherein there are between 4 and 14 carbon atoms connected between the carbonyl group and the oxygen atom derived from the hydroxyl group.  
   
   
       6 . The method according to  claim 2  wherein A includes at least one substituent selected from the group consisting of hydroxy, halo, and alkoxy groups.  
   
   
       7 . The method according to  claim 2  wherein X q−  is selected from the group consisting of sulfate and sulfonate anions.  
   
   
       8 . The method according to  claim 1  wherein Y contains up to 50 carbon atoms and is selected from the group consisting of aryl, alkyl, and alkenyl groups and combinations thereof.  
   
   
       9 . The method according to  claim 1  wherein Y is selected from the group consisting of heptyl, octyl, undecyl, lauryl, heptadecyl, heptadenyl, heptadecadienyl, stearyl, oleyl, and linoleyl groups, and combinations thereof.  
   
   
       10 . The method according to  claim 1  wherein Y comprises a moiety selected from the group consisting of C 4-8  cycloalkyls, polycycloalkyls, aryls, aralkyls, polyaryls, and combinations thereof.  
   
   
       11 . The method according to  claim 1  wherein the poly(hydroxycarboxylic acid) is selected from the group consisting of poly(hydroxystearic acid) and poly(hydroxyoleic acid).  
   
   
       12 . The method according to  claim 1  wherein the amine is a diamine selected from the group consisting of ethylenediamine and N,N-dimethyl-1,3-propanediamine.  
   
   
       13 . The method according to  claim 1  wherein the poly(hydroxycarboxylic acid) amide salt derivative contains sulfur.  
   
   
       14 . The method according to  claim 1 , further including providing said at least one poly(hydroxycarboxylic acid) amide salt derivative in an amount in the range of from 0.1 to 10.0 wt. %, based on the total weight of the lubricating oil composition.  
   
   
       15 . The method according to  claim 1  wherein said lubricating oil composition further comprises at least one detergent selected from the group consisting of alkali metal or alkaline earth metal salicylate, phenate, and sulfonate detergents, and combinations thereof.