Patent ID: 6593426
Filing Date: 2003-07-15
Classification: C10L

Abstract:
An additive for improving the cold flow properties of middle distillates, containing from 10 to 95% by weight of copolymers A), from 5 to 90% by weight of copolymers B) and, if required, from 0 to 70% by weight of copolymers C), which correspond to the following formulae:A) copolymers of lower olefins and vinyl esters, containing A1) from 85 to 97 mol % of bivalent structural units of the formula â€”CH2â€”CR1R2â€”â€ƒâ€ƒA1 â€ƒin which R1 and R2, independently of one another, are hydrogen or methyl, and A2) at least 3 mol % of bivalent structural units of the formula in which R3 is saturated, branched C6-C16-alkyl which has a tertiary carbon atom, wherein R3 is bonded with its tertiary carbon atom to the carboxyl function,B) copolymers comprising B1) from 40 to 60 mol % of bivalent structural units of the formula â€ƒwhere X is O or Nâ€”R4and in which a and bare 0 or 1 and a +b=1, and B2) from 60 to 40 mol % of bivalent structural units of the formula â€”H2Câ€”CR11R5â€”â€ƒâ€ƒB2 â€ƒand, if required, B3) from 0 to 20 mol % of bivalent structural units which are derived from polyolefins, the polyolefins being derivable from monoolefins having 3 to 5 carbon atoms, and in which a) R4 is an alkyl or alkenyl radical having 10 to 40 carbon atoms or an alkoxyalkyl radical having 1 to 100 alkoxy units and 1 to 30 carbon atoms in the alkyl radical, and b) R5 is a radical of the formula OCOR12 or COOR12, in which R12 is C1- to C3-alkyl, and c) the number of carbon atoms of the polyolefin molecules on which the structural units B3) are based is from 35 to 350, and d) R11 is hydrogen or methyl, and, if required, C) a further copolymer differing from A) and B) and comprising ethylene and one or more vinyl esters or acrylates, which by itself is effective as a cold flow improver for middle distillates.