Additive concentrate

Abstract

An additive concentrate comprises a lubricity enhancer dissolved in a solvent. The lubricity enhancer comprises from 10 to 90% by weight of the concentrate and is a salt formed by the reaction of a carboxylic acid with di-n-butylamine or tri-n-butylamine. The concentrates have excellent low temperature stability.

1 . An additive concentrate comprising a lubricity enhancer dissolved in a solvent; wherein the lubricity enhancer comprises from 10 to 90% by weight of the concentrate; wherein the lubricity enhancer comprises a salt formed by the reaction of a carboxylic acid with di-n-butylamine or tri-n-butylamine; and wherein the concentrate remains clear and bright for at least 14 days when held at −30° C.  
   
   
       2 . A concentrate according to  claim 1 , wherein the lubricity enhancer comprises from 33 to 50% by weight of the concentrate, and wherein the concentrate remains clear and bright for at least 14 days when held at −40° C.  
   
   
       3 . A concentrate according to  claim 1 , wherein the lubricity enhancer comprises from 33 to 50% by weight of the concentrate, and wherein the concentrate remains clear and bright for at least 28 days when held at −30° C.  
   
   
       4 . A concentrate according to  claim 1  wherein the carboxylic acid comprises a fatty acid or a mixture of fatty acids.  
   
   
       5 . A concentrate according to  claim 4  wherein the carboxylic acid comprises tall oil fatty acid or rape seed oil fatty acid.  
   
   
       6 . A concentrate according to  claim 1  wherein the solvent is a hydrocarbon solvent.  
   
   
       7 . A fuel composition comprising a major proportion of a fuel oil and a minor proportion of an additive concentrate comprising a lubricity enhancer dissolved in a solvent; wherein the lubricity enhancer comprises from 10 to 90% by weight of the concentrate; wherein the lubricity enhancer comprises a salt formed by the reaction of a carboxylic acid with di-n-butylamine or tri-n-butylamine; and wherein the concentrate remains clear and bright for at least 14 days when held at −30° C.  
   
   
       8 . A fuel composition according to  claim 7 , wherein the fuel oil comprises a middle distillate fuel oil having a sulphur content of at most 0.05% by weight.  
   
   
       9 . A concentrate according to  claim 7 , wherein the lubricity enhancer comprises from 33 to 50% by weight of the concentrate, and wherein the concentrate remains clear and bright for at least 14 days when held at −40° C.  
   
   
       10 . A concentrate according to  claim 7 , wherein the lubricity enhancer comprises from 33 to 50% by weight of the concentrate, and wherein the concentrate remains clear and bright for at least 28 days when held at −30° C.  
   
   
       11 . A concentrate according to  claim 7  wherein the carboxylic acid comprises a fatty acid or a mixture of fatty acids.  
   
   
       12 . A concentrate according to  claim 11  wherein the carboxylic acid comprises tall oil fatty acid or rape seed oil fatty acid.  
   
   
       13 . A concentrate according to  claim 7  wherein the solvent is a hydrocarbon solvent.  
   
   
       14 . A method for improving the lubricity of a fuel oil having a sulphur content of at most 0.05% by weight comprising: 
 adding an additive concentrate comprising a lubricity enhancer dissolved in a solvent to a fuel oil, wherein the lubricity enhancer comprises a salt formed by the reaction of a carboxylic acid with di-n-butylamine or tri-n-butylamine and is from 10 to 90% by weight of the concentrate, and wherein the concentrate remains clear and bright for at least 14 days when held at −30° C.