High viscosity index wide-temperature functional fluid compositions and methods for their making and use

Abstract

This invention relates to lubricants comprising base stocks and base oils that exhibit an unexpected combination of high viscosity index (130 or greater) and a ratio of measured-to-theoretical high-shear/low-temperature viscosity at −30 C or lower and the methods of making them. Specifically, the present invention relates to novel high viscosity index, low-viscosity lubricants usable as wide-temperature lubricants, for example hyrdraulic oils, comprising novel low-viscosity base stocks, with improved performance in low-temperature viscosity, and methods to produce them.

What is claimed is:  
     
         1 . A functional fluid comprising: 
 a) a base stock or base oil, said base stock or base oil having the properties of: 
 (i) a viscosity index (VI) of about 130 or greater;  
 (ii) a pour point of about −10 C or lower;  
 (iii) a ratio of measured-to-theoretical low-temperature viscosity equal to about 1.2 or less, at a temperature of about −30 C or lower, where the measured viscosity is cold-crank simulator viscosity and where theoretical viscosity is calculated at the same temperature using the Walther-MacCoull equation wherein said base stock or base oil is not a Group IV base stock or base oil; and  
   b) at least one additive.    
     
     
         2 . A functional fluid comprising: 
 a) at least one base stock or base oil wherein said base stock or base oil has a VI of at least 130 produced by a process which comprises: 
 (i) hydrotreating a feedstock having a wax content of at least about 60 wt. %, based on feedstock, with a hydrotreating catalyst under effective hydrotreating conditions such that less than 5 wt. % of the feedstock is converted to 650 F (343 C) minus products to produce a hydrotreated feedstock whose VI increase is less than 4 greater than the VI of the feedstock;  
 (ii) stripping the hydrotreated feedstock to separate gaseous from liquid product;  
 (iii) hydrodewaxing the liquid product with a dewaxing catalyst which is at least one of ZSM-48, ZSM-57, ZSM-23, ZSM-22, ZSM-35, ferrierite, ECR-42, ITQ-13, MCM-71, MCM-68, beta, fluorided alumina, silica-alumina or fluorided silica alumina under catalytically effective hydrodewaxing conditions wherein the dewaxing catalyst contains at least one Group 9 or Group 10 noble metal; and  
   b) at least one additive.    
     
     
         3 . A functional fluid comprising: 
 a) at least one base stock or base oil wherein said base stock has a VI of at least 130 produced by a process which comprises: 
 (i) hydrotreating a lubricating oil feedstock having a wax content of at least about 50 wt. %, based on feedstock, with a hydrotreating catalyst under effective hydrotreating conditions such that less than 5 wt. % of the feedstock is converted to 650 F (343 C) minus products to produce a hydrotreated feedstock to produce a hydrotreated feedstock whose VI increase is less than 4 greater than the VI of the feedstock;  
 (ii) stripping the hydrotreated feedstock to separate gaseous from liquid product;  
 (iii) hydrodewaxing the liquid product with a dewaxing catalyst which is at least one of ZSM-22, ZSM-23, ZSM-35, ferrierite, ZSM-48, ZSM-57, ECR-42, ITQ-13, MCM-68, MCM-71, beta, fluorided alumina, silica-alumina or fluorided silica-alumina under catalytically effective hydrodewaxing conditions wherein the dewaxing catalyst contains at least one Group 9 or 10 noble metal;  
 (iv) hydrofinishing the product from step (3) with a mesoporous hydrofinishing catalyst from the M41S family under hydrofinishing conditions; and  
   b) at least one additive.    
     
     
         4 . A functional fluid comprising: 
 a) at least one base stock wherein said base stock has a VI of at least 130 produced by a process which comprises: 
 (i) hydrotreating a lubricating oil feedstock having a wax content of at least about 60 wt. %, based on feedstock, with a hydrotreating catalyst under effective hydrotreating conditions such that less than 5 wt. % of the feedstock is converted to 650 F (343 C) minus products to produce a hydrotreated feedstock to produce a hydrotreated feedstock whose VI increase is less than 4 greater than the VI of the feedstock;  
 (ii) stripping the hydrotreated feedstock to separate gaseous from liquid product;  
 (iii) hydrodewaxing the liquid product with a dewaxing catalyst which is ZSM-48 under catalytically effective hydrodewaxing conditions wherein the dewaxing catalyst contains at least one Group 9 or 10 noble metal;  
 (iv) Optionally, hydrofinishing the product from step (3) with MCM-41 under hydrofinishing conditions; and  
   b) at least one additive.    
     
     
         5 . The functional fluid as in  claim 2 ,  3  or  4  wherein said feedstock is a synthetic gas to liquid feedstock.  
     
     
         6 . The functional fluid as in claims  2 ,  3  or  4  wherein said feedstock is made by a Fischer-Tropsch process.  
     
     
         7 . The functional fluid having improved Brookfield viscosity at −20 F or lower comprising the base stock or base oil of claims  1 ,  2 ,  3  or  4  and at least one performance enhancing additive.  
     
     
         8 . The functional fluid having improved Brookfield viscosity at −20 F or lower comprising the base stock or base oil of claims  1 ,  2 ,  3  or  4  and at least one performance enhancing additive, where said performance enhancing additive is not a viscosity index improver.  
     
     
         9 . A functional fluid composition comprising the base oil or base stock of any one of the claims  1 ,  2 ,  3  or  4 , wherein the Brookfield viscosity is less than or equal to about 40000 cP at −20 F.  
     
     
         10 . A functional fluid composition comprising the base oil or base stock of any one of the claims  1 ,  2 ,  3  or  4 , wherein the Brookfield viscosity is less than or equal to about 28000 cP at −20 F.  
     
     
         11 . A functional fluid composition comprising the base oil or base stock of any one of the claims  1 ,  2 ,  3  or  4 , wherein the Brookfield viscosity is less than or equal to about 6500 cP at −20 F.  
     
     
         12 . A functional fluid composition comprising the base oil or base stock of any one of the claims  1 ,  2 ,  3  or  4 , wherein the Brookfield viscosity is less than or equal to about 6200 cP at −20 F  
     
     
         13 . The method of making a functional fluid having improved Brookfield viscosity at −20 F or lower comprising incorporating a base stock or base oil having the properties of 
 (a) a viscosity index (VI) of 130 or greater,  
 (b) a pour point of −10 C or lower,  
 (c) a ratio of measured-to-theoretical low-temperature viscosity equal to 1.2 or less, at a temperature of −30 C or lower, where the measured viscosity is cold-crank simulator viscosity and where theoretical viscosity is calculated at the same temperature using the Walther-MacCoull equation.  
 wherein said base stock or base oil is not a Group IV base stock or base oil.  
 
     
     
         14 . A method of improving the Brookfield viscosity of a base stock comprising incorporating said base stock or base oil of any one of the claims  1 ,  2 ,  3  or  4 .  
     
     
         15 . A method of improving the Brookfield viscosity of a functional fluid comprising incorporating a base stock or base oil of any one of the claims  1 ,  2 ,  3  or  4 .  
     
     
         16 . A method of improving the Brookfield viscosity of a hydraulic oil comprising incorporating a base stock or base oil of any one of the claims  1 ,  2 ,  3  or  4 .  
     
     
         17 . A method of improving a functional fluid by admixing the base oil or base stock of any one of the claims  1 ,  2 ,  3  or  4 , wherein the Brookfield viscosity of the final mixture is less than or equal to about 40000 cP at −20 F.  
     
     
         18 . A method of improving a functional fluid by admixing the base oil or base stock of any one of the claims  1 ,  2 ,  3  or  4 , wherein the Brookfield viscosity of the final mixture is less than or equal to about 28000 cP at −20 F.  
     
     
         19 . A method of improving a functional fluid by admixing the base oil or base stock of any one of the claims  1 ,  2 ,  3  or  4 , wherein the Brookfield viscosity of the final mixture is less than or equal to about 6500 cP at −20 F.  
     
     
         20 . A method of improving a functional fluid by admixing the base oil or base stock of any one of the claims  1 ,  2 ,  3  or  4 , wherein the Brookfield viscosity of the final mixture is less than or equal to about 6200 cP at −20 F  
     
     
         21 . Any one of the proceeding claims wherein the functional fluid is a hydraulic oil.