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 18 to 35 mol % of at least one acrylic ester or vinyl ester having a C 1 -C 18 -alkyl radical and a degree of branching of less than 5 CH 3 /100 CH 2 groups, 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, 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 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 18 to 35 mol % of at least one acrylic ester or vinyl ester having a C 1 -C 18 -alkyl radical and a degree of branching of less than 5 CH 3 /100 CH 2  groups, 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 C8-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, 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 18.5 to 27 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 4 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 100 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.