Performance-enhancing additives for lubricating oils

Abstract

A lubricant exhibiting enhanced properties, including improved load-carrying capacity and wear reduction, includes synthetic and/or mineral oil as a major ingredient, and a performance-enhancing amount of vegetable oil. In addition to providing improved performance characteristics, the vegetable oil additive reduces the need for certain other additives, including pour point depressants and viscosity index improvers, thereby simultaneously lowering the overall cost of the lubricant.

1 . A lubricant exhibiting excellent high temperature oxidative stability, comprising: 
 from about 95% to about 75% (by volume) of a mineral and/or synthetic oil optionally containing performance-enhancing additives; and    from about 5% to about 25% (by volume) of a vegetable oil having an oleic content of less than 50%.    
   
   
       2 . The lubricant of  claim 1 , wherein the vegetable oil is corn oil.  
   
   
       3 . The lubricant of  claim 1 , wherein the vegetable oil is deodorized corn oil.  
   
   
       4 . The lubricant of  claim 1 , further comprising a dialkyldithiocarbamate salt.  
   
   
       5 . The lubricant of  claim 1 , further comprising zinc dialkyldithiocarbamate in an amount effective to enhance oxidative stability.  
   
   
       6 . The lubricant of  claim 1 , wherein pour point depressant additives are not present or are present in an amount less than 0.5%.  
   
   
       7 . The lubricant of  claim 1 , wherein the vegetable oil comprises from about 20% to about 25% of the lubricant by volume.  
   
   
       8 . The lubricant of  claim 1 , having a pour point temperature less than −37° F.  
   
   
       9 . The lubricant of  claim 1 , wherein the vegetable oil comprises greater than 20% of the lubricant by volume.  
   
   
       10 . The lubricant of  claim 1 , wherein the vegetable oil comprises greater than 10% corn oil by volume, and further comprises an antioxidant.  
   
   
       11 . The lubricant of  claim 10 , wherein the antioxidant is a dialkyldithiocarbamate salt.  
   
   
       12 . The lubricant of  claim 11 , wherein the dialkyldithiocarbamate salt is zinc diamyldithiocarbamate.  
   
   
       13 . The lubricant of  claim 11 , wherein the dialkylthiocarbamate salt is a molybdenum dialkyldithiocarbamate.  
   
   
       14 . The lubricant of  claim 10 , wherein the antioxidant is an alkylated diphenylamine.  
   
   
       15 . The lubricant of  claim 10 , wherein the antioxidant comprises methylene bis (N,N-dibutyldithiocarbamate).  
   
   
       16 . The lubricant of  claim 1 , wherein the vegetable oil is corn oil and comprises from 20% to 25% by weight of the lubricant, and wherein the viscosity index improver additives are not present.  
   
   
       17 . The lubricant of  claim 1 , wherein phosphorus-containing additives are not present or wherein phosphorus-containing additive(s) are present in an amount less than 0.08% (by weight).  
   
   
       18 . An internal combustion engine lubricated with the lubricant of  claim 1 .  
   
   
       19 . An automotive transmission lubricated with the lubricant of  claim 1 .  
   
   
       20 . A lubricant comprising: 
 synthetic and/or mineral oil;    a performance-enhancing amount of vegetable oil; and    an antioxidant selected from dialkyldithiocarbamate salts, alkylated diphenylamines, and methylene bis (N,N-dibutyldithiocarbamate).    
   
   
       21 . The lubricant of  claim 20 , wherein the vegetable oil is corn oil.  
   
   
       22 . The lubricant of  claim 20 , wherein the vegetable oil is deodorized corn oil.  
   
   
       23 . The lubricant of  claim 20 , wherein the vegetable oil comprises from about 20% to about 25% of the lubricant by volume.  
   
   
       24 . The lubricant of  claim 20 , wherein the dialkyldithiocarbamate salt is zinc diamyldithiocarbamate.  
   
   
       25 . The lubricant of  claim 20 , wherein the dialkylthiocarbamate salt is a molybdenum dialkyldithiocarbamate.  
   
   
       26 . The lubricant of  claim 20 , wherein the antioxidant is an alkylated diphenylamine.  
   
   
       27 . The lubricant of  claim 20 , wherein the vegetable oil is corn oil and comprises from 20% to 25% by weight of the lubricant, and wherein the viscosity index improver additives are not present.  
   
   
       28 . The lubricant of  claim 20 , wherein phosphorus-containing additives are not present or wherein phosphorus-containing additive(s) are present in an amount less than 0.08% (by weight).