Olefinic Copolymer Compositions for Viscosity Modification of Motor Oil

Abstract

Lube oil compositions and methods for making the same are provided. The lubricating oil composition can include at least one propylene-based polymer comprising 60 wt % to 98 wt % propylene derived units, other units derived from one or more other alpha olefins, and a base oil. The propylene-based polymer can have a triad tacticity of 90% or more, a heat of fusion of less than 80 J/g, and a weight average molecular weight (Mw) as measured by GPC of from 70,000 to 250,000.

1 . A lubricating oil composition comprising:
 at least one propylene-based polymer comprising 60 wt % to 98 wt % propylene derived units and 2 wt % to 40 wt % units derived from one or more other alpha olefins, the propylene-based polymer having:
 a triad tacticity of 90% or more, 
 a heat of fusion of less than 80 J/g, 
 a weight average molecular weight (Mw) as measured by GPC of from 70,000 to 250,000, and 
 a MWD of 2.0 to 2.5; and 
   a base oil.   
     
     
         2 . The lubricating oil composition of  claim 1 , wherein the propylene-based polymer comprises 70 wt % to 95 wt % propylene derived units and 5 wt % to 30 wt % units derived from one or more other alpha olefins. 
     
     
         3 . (canceled) 
     
     
         4 . The lubricating oil composition of  claim 1 , wherein the propylene-based polymer comprises 80 wt % to 90 wt % propylene derived units and 5 wt % to 20 wt % units derived from one or more other alpha olefins. 
     
     
         5 . The lubricating oil composition of  claim 1 , wherein the propylene-based polymer comprises 80 wt % to 90 wt % propylene derived units and 10 wt % to 20 wt % units derived from one or more other alpha olefins. 
     
     
         6 . The lubricating oil composition of  claim 1 , wherein the propylene-based polymer comprises 80 wt % to 88 wt % propylene derived units and 12 wt % to 20 wt % units derived from one or more other alpha olefins. 
     
     
         7 . The lubricating oil composition of  claim 1 , wherein the alpha olefin is ethylene. 
     
     
         8 . The lubricating oil composition of  claim 1 , wherein the alpha olefin is butene. 
     
     
         9 . The lubricating oil composition of  claim 1 , wherein the one or more other alpha olefins comprises one or more C 4  to C 12  alpha-olefins. 
     
     
         10 . The lubricating oil composition of  claim 1 , wherein the propylene derived units are isotactic. 
     
     
         11 . The lubricating oil composition of  claim 1 , wherein the weight average molecular weight (Mw) is about 80,000 to about 200,000. 
     
     
         12 .- 13 . (canceled) 
     
     
         14 . The lubricating oil composition of  claim 1 , wherein the MWD is of from 2.1 to 2.4. 
     
     
         15 . The lubricating oil composition of  claim 1 , wherein the propylene-based polymer comprises of from 10 wt % to 20 wt % units derived from ethylene. 
     
     
         16 . The lubricating oil composition of  claim 1 , wherein the propylene-based polymer has a MFR (2.16 kg, 230° C.) as measured by ASTM-D1238 of from 3.0 g/10 min to about 21 g/10 min. 
     
     
         17 . The lubricating oil composition of  claim 1 , further comprising at least one of a dispersant or pour point depressants. 
     
     
         18 . (canceled) 
     
     
         19 . A lubricating oil composition comprising:
 of from 0.5 wt % to 15 wt %, based on the total weight of the lubricating oil composition, at least one propylene-based polymer comprising 70 wt % to 95 wt % propylene derived units and 5 wt % to 30 wt % units derived from one or more other alpha olefins, the propylene-based polymer having:
 a heat of fusion of less than 80 J/g, 
 a weight average molecular weight (Mw) as measured by GPC of from 100,000 to 150,000, and 
 a MWD of 2.0 to 2.5; 
   of from 60 wt % to 98 wt %, based on the total weight of the lubricating oil composition, a base oil;   of from 0.1 wt % to 20 wt %, based on the total weight of the lubricating oil composition, one or more dispersants; and   of from 0.1 wt % to 10 wt %, based on the total weight of the lubricating oil composition, one or more pour point depressants.   
     
     
         20 . (canceled) 
     
     
         21 . The lubricating oil composition of  claim 19 , wherein the oil composition has a thickening efficiency of about 1.5 to 2.5, wherein the thickening efficiency is defined as:
     TE= 2 /c ×ln(( kv  of polymer+oil)/( kv  of oil))/ln(2)
   where c is the concentration of the propylene-based polymer.   
     
     
         22 .- 23 . (canceled) 
     
     
         24 . The lubricating oil composition of  claim 1 , wherein the propylene-based polymer is present in an amount of from 1.0 wt % to 10 wt %, based on the total weight of the lubricating oil composition. 
     
     
         25 .- 26 . (canceled) 
     
     
         27 . The lubricating oil composition of  claim 1 , comprising:
 of from 0.5 wt % to 15 wt %, based on the total weight of the lubricating oil composition, at least one propylene-based polymer comprising 80 wt % to 88 wt % propylene derived units and 12 wt % to 20 wt % units derived from one or more other alpha olefins, the propylene-based polymer having:
 a triad tacticity of 90% or more; 
 a heat of fusion of less than 80 J/g; 
 a weight average molecular weight (Mw) as measured by GPC of from 100,000 to 250,000; and 
 a MWD of 2.0 to 2.5; and 
   of from 60 wt % to 98 wt %, based on the total weight of the lubricating oil composition, a base oil;   of from 0.1 wt % to 20 wt %, based on the total weight of the lubricating oil composition, one or more dispersants; and   of from 0.1 wt % to 10 wt %, based on the total weight of the lubricating oil composition, one or more pour point depressants.   
     
     
         28 . (canceled) 
     
     
         29 . The lubricating oil composition of  claim 27 , wherein the oil composition has a thickening efficiency of about 1.5 to 2.5, wherein the thickening efficiency is defined as:
     TE= 2 /c ×ln(( kv  of polymer+oil)/( kv  of oil))/ln(2)
   where c is the concentration of the propylene-based polymer.   
     
     
         30 .- 32 . (canceled) 
     
     
         33 . A method for preparing a lubricating oil composition, the method comprising combining:
 (i) at least one propylene-based polymer comprising 60 wt % to 98 wt % propylene derived units and 2 wt % to 40 wt % units derived from one or more other alpha olefins, the propylene-based polymer having:
 a triad tacticity of 90% or more; 
 a heat of fusion of less than 80 J/g; 
 a weight average molecular weight (Mw) as measured by GPC of from 70,000 to 250,000; and 
 a MWD of 2.0 to 2.5; and 
   (ii) a base oil.   
     
     
         34 . The lubricating oil composition of  claim 1 , wherein the propylene-based polymer is grafted with a grafting monomer that is at least one ethylenically unsaturated carboxylic acid or acid derivative. 
     
     
         35 . The lubricating oil composition of  claim 1 , wherein the propylene-based polymer is grafted with at least one of maleic acid or maleic anhydride. 
     
     
         36 . The lubricating oil composition of  claim 34 , wherein the grafted propylene-based polymer comprises from about 0.5 to about 6 wt % ethylenically unsaturated carboxylic acid or acid derivative. 
     
     
         37 . The lubricating oil composition of  claim 34 , wherein the grafted propylene-based polymer comprises from about 1 to about 3 wt % maleic acid or maleic anhydride. 
     
     
         38 . The lubricating oil composition of  claim 34 , wherein the grafted propylene-based polymer comprises from about 1.5 wt % maleic acid.