Novel Copolymers and Lubricating Compositions Thereof

Abstract

The present invention relates to a copolymer comprising units derived from monomers (i) an α-olefin and (ii) an ethylenically unsaturated carboxylic acid or derivatives thereof esterified with a primary alcohol branched at the β- or higher position, wherein the copolymer has a reduced specific viscosity of up to 0.08. The invention further provides for a lubricating composition containing said copolymer. The invention further provides a method and use of controlling viscosity index by supplying to an oil of lubricating viscosity the copolymer with pendant groups. In addition, the copolymer of the present invention may be useful as a base oil replacement.

What is claimed is: 
     
         1 .- 41 . (canceled) 
     
     
         42 . A lubricating composition comprising an oil of lubricating viscosity and 1.5 wt % to 65 wt % of a copolymer comprising units derived from monomers (i) an α-olefin and (ii) an ethylenically unsaturated carboxylic acid or derivatives thereof esterified with a primary alcohol branched at the β- or higher position, wherein the copolymer prior to esterification has a reduced specific viscosity of up to 0.08, wherein the primary alcohol branched at the β- or higher position has at least 12 to 60 carbon atoms, and wherein the α-olefin has 10 to 18 carbon atoms. 
     
     
         43 . The lubricating composition of  claim 42 , wherein the ethylenically unsaturated carboxylic acid or derivatives thereof is maleic anhydride. 
     
     
         44 . The lubricating composition of  claim 42 , wherein the copolymer has a reduced specific viscosity of 0.02 to 0.07. 
     
     
         45 . The lubricating composition of  claim 42 , wherein the copolymer is composed of units derived from monomers of (i) an α-olefin having 12 carbon atoms, and (ii) maleic anhydride. 
     
     
         46 . The lubricating composition of  claim 42 , wherein the copolymer is further amidated or imidated with a nitrogen-containing compound. 
     
     
         47 . The lubricating composition of  claim 46 , wherein the nitrogen-containing compound is an amine-containing compound selected from the group consisting of morpholines, imidazolidinones, acetamides, β-alanine alkyl esters, and mixtures thereof. 
     
     
         48 . The lubricating composition of  claim 47 , wherein the amine-containing compound is selected from morpholines, imidazolidinones, and mixtures thereof. 
     
     
         49 . The lubricating composition of  claim 47 , wherein the amine-containing compound is selected from the group consisting of 1-(2-amino-ethyl)-imidazolidin-2-one, 4-(3-aminopropyl)morpholine, 3-(dimethylamino)-1-propylamine, N-phenyl-p-phenylenediamine, N-(3-aminopropyl)-2-pyrrolidinone, aminoethyl acetamide, β-alanine methyl ester, 1-(3-aminopropyl)imidazole, and mixtures thereof. 
     
     
         50 . The lubricating composition of  claim 42 , wherein the copolymer comprises units derived from monomers (i) an α-olefin and (ii) an ethylenically unsaturated carboxylic acid or derivatives thereof,
 wherein 75% to 99.9 percent of the carboxylic acid units are esterified with a primary alcohol branched at the β- or higher position, and 
 wherein 0.1 to 25% of the carboxylic acid units are amidated or imidated with a nitrogen-containing compound. 
 
     
     
         51 . The lubricating composition of  claim 42 , wherein the copolymer is an alternating copolymer. 
     
     
         52 . The lubricating composition of  claim 42 , wherein the primary alcohol branched at the β- or higher position is a Guerbet alcohol. 
     
     
         53 . The lubricating composition of  claim 42 , wherein the copolymer is prepared by a process comprising the steps of:
 (1) reacting (i) an α-olefin and (ii) an ethylenically unsaturated carboxylic acid or derivatives thereof or derivatives thereof to form a copolymer;   (2) esterifying the copolymer of step (1) with a primary alcohol branched at the β- or higher position to form an esterified copolymer; and   (3) optionally reacting the esterified copolymer of step (2) with an amine in an amount to provide the esterified copolymer with 0.01 wt % to 1.5 wt % nitrogen,   wherein the primary alcohol branched at the β- or higher position may have at least 12 to 60 carbon atoms;   wherein the α-olefin has 10 to 18 carbon atoms and   wherein the copolymer of step (1) has a reduced specific viscosity of up to 0.08.   
     
     
         54 . The lubricating composition of  claim 53 , wherein the process further comprises step (3). 
     
     
         55 . The lubricating composition of  claim 42 , wherein the copolymer is present at 10 wt % to 60 wt % of the lubricating composition. 
     
     
         56 . The lubricating composition of claim  1 , wherein the copolymer is present at 20 wt % to 60 wt % of the lubricating composition. 
     
     
         57 . The lubricating composition of  claim 42 , wherein the copolymer is present at 27 wt % to 58 wt % of the lubricating composition.