Cold flow improvers for vegetable or animal fuel oils

Abstract

The present invention relates to a fuel oil additive comprising A) a copolymer of ethylene and from 13 to 17 mol % of at least one acrylic ester or vinyl ester having a C 1 -C 18 -alkyl radical and a melt viscosity V 140 of not more than 80 mPas, and B) a comb polymer comprising structural units formed from B1) at least one olefin as monomer 1, which bears at least one C 8 -C 18 -alkyl radical on the olefinic double bond, and B2) at least one ethylenically unsaturated dicarboxylic acid as monomer 2, which bears at least one C 8 -C 16 -alkyl radical bonded via an amide and/or imide group, in which the parameter Q Q = ∑ i  w 1   i · n 1  i + ∑ j  w 2  j · n 2  j in which w 1 is the molar proportion of the individual chain lengths n 1 in the alkyl radicals of monomer 1, w 2 is the molar proportion of the individual chain lengths n 2 in the alkyl radicals of the amide and/or imide groups of monomer 2, n 1 are the individual chain lengths in the alkyl radicals of monomer 1, n 2 are the individual chain lengths in the alkyl radicals of the amide and/or imide groups of monomer 2, i is the serial variable for the chain lengths in the alkyl radicals of monomer 1, and j is the serial variable for the chain lengths in the alkyl radicals of the amide and/or imide groups of monomer 2 assumes values of from 23 to 27.

1 . A fuel oil additive comprising
 A) a copolymer of ethylene and from 13 to 17 mol % of at least one acrylic ester or vinyl ester having a C 1 -C 18 -alkyl radical and a melt viscosity V 140  of not more than 80 mPas, and   B) a comb polymer comprising structural units formed from   B1) at least one olefin as monomer 1, which bears at least one C 8 -C 18 -alkyl radical on the olefinic double bond, and   B2) at least one ethylenically unsaturated dicarboxylic acid as monomer 2, which bears at least one C 8 -C 16 -alkyl radical bonded via an amide and/or imide group,   in which the parameter Q   
       
         
           
             
               Q 
               = 
               
                 
                   
                     ∑ 
                     i 
                   
                    
                   
                     
                       w 
                       
                         1 
                          
                         
                             
                         
                          
                         i 
                       
                     
                     · 
                     
                       n 
                       
                         1 
                          
                         i 
                       
                     
                   
                 
                 + 
                 
                   
                     ∑ 
                     j 
                   
                    
                   
                     
                       w 
                       
                         2 
                          
                         j 
                       
                     
                     · 
                     
                       n 
                       
                         2 
                          
                         j 
                       
                     
                   
                 
               
             
           
         
       
       in which
 w 1  is the molar proportion of the individual chain lengths n 1  in the alkyl radicals of monomer 1, 
 w 2  is the molar proportion of the individual chain lengths n 2  in the alkyl radicals of the amide and/or imide groups of monomer 2, 
 n 1  are the individual chain lengths in the alkyl radicals of monomer 1, 
 n 2  are the individual chain lengths in the alkyl radicals of the amide and/or imide groups of monomer 2, 
 i is the serial variable for the chain lengths in the alkyl radicals of monomer 1, and 
 j is the serial variable for the chain lengths in the alkyl radicals of the amide and/or imide groups of monomer 2 
 
       assumes values of from 23 to 27. 
     
     
         2 . The fuel oil additive as claimed in  claim 1 , wherein Q assumes values of from 24 to 26. 
     
     
         3 . The fuel oil additive as claimed in  claim 1 , wherein constituent A) comprises from 15 to 17 mol % of at least one vinyl ester. 
     
     
         4 . The fuel oil additive of  claim 1 , wherein constituent A) comprises from 0.5 to 10 mol % of olefins having from 3 to 10 carbon atoms. 
     
     
         5 . The fuel oil additive of  claim 1 , wherein the degree of branching of constituent A) is less than 6 CH 3 /100 CH 2  groups, determined by means of  1 H NMR spectroscopy. 
     
     
         6 . The fuel oil additive of  claim 1 , wherein the at least one olefin which forms constituent B1) is an α-olefin. 
     
     
         7 . The fuel oil additive of  claim 1 , wherein a molar ratio of comonomer B1) to comonomer B2) in copolymer B) is between 1.5:1 and 1:1.5. 
     
     
         8 . The fuel oil additive of  claim 1 , wherein copolymer B, as well as comonomers B1) and B2), further comprises up to 20 mol % of a further comonomer other than B1) and B2), selected from the group consisting of an olefin having from 2 to 50 carbon atoms, an allyl polyglycol ether, a C 1 -C 30 -alkyl(meth)acrylate, a vinylaromatic or a C 1 -C 20 -alkyl vinyl ether, and a polyisobutene having molecular weights of up to 5000 g/mol. 
     
     
         9 . The fuel oil additive of  claim 1 , wherein constituent A) has a melt viscosity V 140  of from 5 to 80 mPas. 
     
     
         10 . The fuel oil additive of  claim 1 , wherein constituent A) has a molecular weight of from 1000 to 10 000 g/mol. 
     
     
         11 . The fuel oil additive of  claim 1 , in which constituent B) has a molecular weight Mw of from 1200 to 200 000 g/mol. 
     
     
         12 . A fuel oil composition comprising a fuel oil of vegetable or animal origin and the fuel oil additive of  claim 1 . 
     
     
         13 . The fuel oil composition as claimed in  claim 12 , wherein the fuel oil further comprises a mixture of fatty acid esters of C 1 - to C 4 -alcohols. 
     
     
         14 . The fuel oil composition as claimed in  claim 13 , wherein the fatty acid esters include stearic acid methyl ester and palmitic acid methyl ester in a proportion of at least 7% by weight. 
     
     
         15 . A process for improving the cold behavior of fuel oils of vegetable or animal origin, said process comprising admixing a portion of the fuel oil additive of  claim 1  with said fuel oil.