Bright stock base oil blend

Abstract

A method is disclosed for making a bright stock base oil blend meeting API Group II specifications. The method comprises blending (a) a major amount of a petroleum-derived bright stock component having kinematic viscosity at 100° C. of from 20 to 50 mm 2 /s with a sufficient amount of (b) a propylene oligomer component having a viscosity index of from 30 to 60, to provide a bright stock base oil blend having a higher viscosity than the petroleum-derived bright stock component and a higher viscosity index than the propylene oligomer component.

1 . A method for making a bright stock base oil blend meeting API Group II specifications comprising: blending (a) a major amount of a petroleum-derived bright stock component having kinematic viscosity at 100° C. of from 20 to 50 mm 2 /s with a sufficient amount of (b) a propylene oligomer component having a viscosity index of from 30 to 60, to provide a bright stock base oil blend having a higher viscosity than the petroleum-derived bright stock component and a higher viscosity index than the propylene oligomer component. 
     
     
         2 . The method of  claim 1 , wherein the blend comprises from 60 to 90% of the petroleum-derived bright stock component and from 40 wt. % to 10 wt. % of the propylene oligomer component, based on the total weight of the blend. 
     
     
         3 . The method of  claim 1 , wherein the blend comprises from 70 to 85% of the petroleum-derived bright stock component and from 30 wt. % to 15 wt. % of the propylene oligomer component, based on the total weight of the blend. 
     
     
         4 . The method of  claim 1 , wherein the blend has a kinematic viscosity at 100° C. that is at least 3 mm 2 /s higher than that of the petroleum-derived bright stock component. 
     
     
         5 . The method of  claim 1 , wherein the blend has a viscosity index that is at least 20 higher than that of the propylene oligomer component. 
     
     
         6 . The method of  claim 1 , wherein the blend has a pour point that is at least 1° C. lower than that of the petroleum-derived bright stock component. 
     
     
         7 . The method of  claim 1 , wherein the blend has a cloud point that is at least 1° C. lower than that of the petroleum-derived bright stock component. 
     
     
         8 . The method of  claim 1 , wherein the petroleum-derived bright stock component has a viscosity index of from 80 to less than 120. 
     
     
         9 . The method of  claim 1 , wherein the petroleum-derived bright stock component has a viscosity index of from 120 to 145. 
     
     
         10 . The method of  claim 1 , wherein the petroleum-derived bright stock component has a pour point of 0° C. or less. 
     
     
         11 . The method of  claim 1 , wherein the petroleum-derived bright stock component has a cloud point of 15° C. or less. 
     
     
         12 . The method of  claim 1 , wherein the propylene oligomer component has a kinematic viscosity at 100° C. of from 50 to 100 mm 2 /s. 
     
     
         13 . The method of  claim 1 , wherein the propylene oligomer component has a pour point of −10° C. or less. 
     
     
         14 . The method of  claim 1 , wherein the propylene oligomer component has a cloud point of −25° C. or less.