Environmentally friendly lubricants

Abstract

A biodegradable lubricant that is at least 60% biodegradable and has a gelation index of about 12 or less can be formulated using a transesterified triglyceride base oil together with a synthetic ester. A combination of an ester viscosity index improver and an olefin copolymer viscosity index improver also can be added. Further, the composition can be blended with mineral oils to lower the polarity in order to employ standard dispersant/inhibitor packages. Further, by mixing high and low viscosities of mineral oil in the formulation, it is possible to prepare a full range of SAE grade engine oils for gasoline-fueled and diesel-fueled engines.

What is claimed is:  
     
         1 . An environmentally friendly lubricant, comprising: 
 a) a transesterified triglycerol oil; and    b) a first ester different from the triglycerol oil;    wherein the environmentally friendly lubricant is at least 60% biodegradable and has a gelation index less than about 12.    
     
     
         2 . The environmentally friendly lubricant of  claim 1  further comprising: 
 c) a second ester as a polar viscosity index improver; and  
 d) a hydrogenated copolymer as a non-polar viscosity index improver wherein the second ester is different from the first ester and the triglycerol oil.  
 
     
     
         3 . The environmentally friendly lubricant of  claim 2  further comprising: 
 e) a dispersant/inhibitor package; and  
 f) at least one additive.  
 
     
     
         4 . The environmentally friendly lubricant of  claim 2  wherein the hydrogenated olefin copolymer is a hydrogenated ethylene-propene viscosity index improver.  
     
     
         5 . The environmentally friendly lubricant of  claim 1  wherein the triglyceride is in the amount from about 30 to about 85 wt %.  
     
     
         6 . The environmentally friendly lubricant of  claim 1  wherein the first ester is in the amount from about 10 to about 30 wt %.  
     
     
         7 . The environmentally friendly lubricant of  claim 2  wherein the second ester is in the amount from about 0.1 to about 3 wt %.  
     
     
         8 . The environmentally friendly lubricant of  claim 2  wherein the hydrogenated olefin copolymer is in the amount from about 0.1 to about 6 wt %.  
     
     
         9 . The environmentally friendly lubricant of  claim 3  wherein the dispersant/inhibitor package is in the amount from about 8 to about 14 wt %.  
     
     
         10 . The environmentally friendly lubricant of  claim 3  wherein the at least one additive is a pour point depressant, antioxidant, friction modifier, rust inhibitor, corrosion inhibitor anti-foaming agent or a combination thereof in the amount from about 0.1 to about 5 wt %.  
     
     
         11 . The environmentally friendly lubricant of  claim 2  further comprising mineral oil or synthetic oil.  
     
     
         12 . The environmentally friendly lubricant of  claim 11  wherein the mineral oil or synthetic oil is in the amount from about 0.1 to about 30 wt %.  
     
     
         13 . The environmentally friendly lubricant of  claim 1 , wherein the transesterified triglycerol oil is a mixture of a glycerol polyol ester and a non-glycerol polyol ester.  
     
     
         14 . The environmentally friendly lubricant of  claim 1 , wherein the transesterified triglycerol oil comprises a glycerol polyol ester but not a non-glycerol polyol ester.  
     
     
         15 . The environmentally friendly lubricant of  claim 1 , wherein the transesterified triglycerol oil comprises a non- glycerol polyol ester but not a glycerol polyol ester.  
     
     
         16 . The environmentally friendly lubricant of  claim 1 , wherein the transesterified triglycerol oil is obtained by transesterifying a vegetable oil with an ester of short-chain fatty acids.  
     
     
         17 . The environmentally friendly lubricant of  claim 1 , wherein the transesterified triglycerol oil is obtained by transesterifying a vegetable oil with a polyol ester.  
     
     
         18 . The environmentally friendly lubricant of  claim 1 , wherein the first ester is dibasic ester.  
     
     
         19 . The environmentally friendly lubricant of  claim 1 , wherein the first ester is tribasic ester.  
     
     
         20 . The environmentally friendly lubricant of  claim 1 , wherein the first ester is polyol ester.  
     
     
         21 . The environmentally friendly lubricant of  claim 1 , wherein the lubricant is an automobile engine oil.  
     
     
         22 . An environmentally friendly automobile engine oil, comprising: 
 a) from about 0.1 to about 6 wt % of an ester as a polar viscosity index improver or a hydrogenated olefin copolymer as a non-polar viscosity index improver or a blend thereof;    b) from about 15 to about 25 wt % of a synthetic ester different from the ester viscosity index improver;    c) from about 20 to about 30 wt % of an mineral oil or a blend thereof; and    d) the balance is made up with a transesterified triglycerol oil,    wherein the environmentally friendly automobile engine oil is at least 60% biodegradable and has a gelation index less than about 12 and the synthetic ester is capable of lowering the gelation index of the engine oil.    
     
     
         23 . The environmentally friendly automobile engine oil of  claim 22  further comprising: from about 0.1 to about 5% of at least one additive.  
     
     
         24 . The environmentally friendly automobile engine oil of  claim 22  wherein the at least one additive is a pour point depressant, antioxidant, friction modifier, rust inhibitor, corrosion inhibitor anti-foaming agent or a combination thereof.  
     
     
         25 . The environmentally friendly automobile engine oil of claim of  claim 22  wherein the automobile engine oil has a viscosity grade of from 0W-20 to 15W-75.  
     
     
         26 . A method of making an environmentally friendly lubricant, the method comprising: 
 blending a transesterified triglycerol oil and a first ester    wherein the environmentally friendly lubricant is at least 60% biodegradable and has a gelation index less than about 12.