Diester-based base oil blends with improved cold flow properties and low noack

Abstract

The present invention is generally directed to diester-based base oils and base oil blends with improved cold flow properties and improved Noack. The diesters employed have a number a performance benefits in lubricant applications—among them: biodegradability, extreme temperature performance, oxidative stability, solubility for additives and deposit and sludge precursors, flash and fire points. However, ester usage in lubricants has been quite limited due to their high cost. We utilize new proprietary diesters, structurally different from traditional diesters, which are made from fatty acids and alpha olefins in simple processing steps, yet feature performance similar to more traditional lubricant esters.

What is claimed is: 
     
         1 . A base oil blend comprising:
 a) a diester component, comprising a quantity of at least one diester species of Formula I:   
       
         
           
           
               
               
           
         
         wherein R 1 , R 2 , R 3  and R 4  are the same or independently selected from C 2  to C 17  hydrocarbon groups; 
         b) a second base oil, and 
       
       wherein the second base oil is a Group I base oil, Group II base oil or Group III base oil. 
     
     
         2 . The base oil blend of  claim 1 , wherein the diester component comprises a mixture of isomers where R 1  and R 2  are different for each isomer. 
     
     
         3 . The base oil blend of  claim 1 , further comprising, a third base oil. 
     
     
         4 . The base oil blend of  claim 1 , wherein the diester component has a Noack Volatility between about 6 and 10 wt %, a CCS Viscosity at −30° C. between about 700 and 2000 cP, a pour point less than about −10° C., a cloud point less than about −10° C., a kinematic viscosity at 100° C. between about 2.5 to 6.5 centistokes, a VI greater than about 110 and a BN Oxidator greater than about 20 hours. 
     
     
         5 . The base oil blend of  claim 1 , wherein the second base oil is light neutral base oil, medium neutral base oil, Yubase 4, Yubase 6, 150R, 600R, 110RLV, 220R or 100R. 
     
     
         6 . The base oil blend of  claims 3 , wherein the third base oil is light neutral base oil, medium neutral base oil, Yubase 4, Yubase 6, 150R, 600R, 110RLV, 220R or 100R. 
     
     
         7 . The base oil blend of  claim 1 , having:
 a) a viscosity index between about 110 to 140;   b) a Noack volatility of less than about 16 wt %;   c) a Pour Point less than about −12° C.; and   d) a Cloud Point less than about −12° C.   
     
     
         8 . The base oil blend of  claim 1 , wherein the kinematic viscosity at a temperature of 100° C. is between about 3 to 5.5 centistokes. 
     
     
         9 . The base oil blend of  claim 7 , wherein the Pour Point and Cloud Point are independently about −20° C. or lower. 
     
     
         10 . The base oil blend of  claim 1 , wherein the CCS Viscosity at −30° C. less than about 4,200 cP. 
     
     
         11 . The base oil blend of  claim 1 , wherein the CCS Viscosity at −35° C. less than about 3,400 cP. 
     
     
         12 . The base oil blend of  claim 1 , wherein the CCS Viscosity at −25° C. less than about 2,400 cP. 
     
     
         13 . The base oil blend of  claim 1 , wherein the Noack Volatility less than about 15 wt %. 
     
     
         14 . The base oil blend of  claim 1 , wherein R 1  and R 2  of Formula I are selected to have a combined carbon number of from 6 to 16 and R 3  and R 4  are selected to have a combined carbon number of from 10 to 34. 
     
     
         15 . The base oil blend of  claim 1 , wherein R 1  and R 2  of Formula I are selected to have a combined carbon number of C 16 , C 14  or C 12  and R 3  and R 4  are independently selected from the group consisting of C 12  and a mixture of C 6 -C 10 . 
     
     
         16 . The base oil blend of  claim 1 , wherein the diester component is derived from a C 8  to C 18  olefin and a C 6  to C 14  carboxylic acid. 
     
     
         17 . The base oil blend of  claim 2 , wherein the diester component comprises quantities of at least two different diester isomers. 
     
     
         18 . The base oil blend of  claim 1 , wherein the diester component has a molecular mass that is from at least about 340 a.m.u. to at most about 780 a.m.u. 
     
     
         19 . The base oil blend of  claim 1 , wherein the diester component is selected from the group consisting of decanoic acid 2-decanoyloxy-1-hexyl-octyl ester and its isomers, tetradecanoic acid-1-hexyl-2-tetradecanoyloxy-octyl esters and its isomers, dodecanoic acid 2-dodecanoyloxy-1-hexyl-octyl ester and its isomers, hexanoic acid 2-hexanoyloxy-1-hexy-octyl ester and its isomers, octanoic acid 2-octanoyloxy-1-hexyl-octyl ester and its isomers, hexanoic acid 2-hexanoyloxy-1-pentyl-heptyl ester and isomers, octanoic acid 2-octanoyloxy-1-pentyl-heptyl ester and isomers, decanoic acid 2-decanoyloxy-1-pentyl-heptyl ester and isomers, decanoic acid-2-cecanoyloxy-1-pentyl-heptyl ester and its isomers, dodecanoic acid-2-dodecanoyloxy-1-pentyl-heptyl ester and isomers, tetradecanoic acid 1-penty-2-tetradecanoyloxy-heptyl ester and isomers, tetradecanoic acid 1-butyl-2-tetradecanoyloxy-hexy ester and isomers, dodecanoic acid-1-butyl-2-dodecanoyloxy-hexyl ester and isomers, decanoic acid 1-butyl-2-decanoyloxy-hexyl ester and isomers, octanoic acid 1-butyl-2-octanoyloxy-hexyl ester and isomers, hexanoic acid 1-butyl-2-hexanoyloxy-hexyl ester and isomers, tetradecanoic acid 1-propyl-2-tetradecanoyloxy-pentyl ester and isomers, dodecanoic acid 2-dodecanoyloxy-1-propyl-pentyl ester and isomers, decanoic acid 2-decanoyloxy-1-propyl-pentyl ester and isomers, octanoic acid 1-2-octanoyloxy-1-propyl-pentyl ester and isomers, hexanoic acid 2-hexanoyloxy-1-propyl-pentyl ester and isomers, and mixtures thereof.