Pour point improvers for vegetable or animal fuel oils

摘要

The invention provides a fuel oil composition comprising a fuel oil of animal or vegetable origin, in which a total of more than 6% by weight of palmitic acid methyl ester and stearic acid methyl ester are present, and, as an additive, A) at least one copolymer which contains 10-20 mol % of structural units of at least one vinyl ester and 80-90 mol % of structural units of ethylene, and B) at least one comb polymer containing structural units formed from B1) at least one olefin as monomer 1, which bears at least one C₈-C₁₈-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-C₁₆-alkyl radical bonded via an amide and/or imide group, in which the parameter Q $Q=\sum _iw_{1i}.n_{1i}+\sum _jw_{2j}.n_{2j}$ in which w₁ is the molar proportion of the individual chain lengths n₁ in the alkyl radicals of monomer 1, w₂ is the molar proportion of the individual chain lengths n₂ in the alkyl radicals of the amide and/or imide groups of monomer 2, n₁ are the individual chain lengths in the alkyl radicals of monomer 1, n₂ 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.