Copolymer blends and their use as an additive for improving the cold flow properties of middle distillates.

摘要

Additives for improving the properties of cold flow of middle distillates containing 10 to 95% by weight of copolymers A), from 5 to 90% by weight of copolymers B) and optionally 0 to 70% by weight copolymers C), which correspond to the following formulas a) copolymers of lower olefins and vinyl esters, containing A1) from 85 to 97 mol% of bivalent structural units of the formula - CH2 - CR1R2 - A1 in which R1 and R2 independently of one another, hydrogen or methyl, and A2) at least 3 mol% of bivalent structural units of the formula wherein R3 is alkyl C6-C16 branched, saturated, having 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 with X = O or N-R4, wherein a, b = 0 or 1 and a + b = 1, and B2) from 60 to 40 mol% of bivalent structural units of the formula - H2C - CR11R5 - B2 and eventually B3) from 0 to 20 mol% of bivalent structural units which are derived from polyolefins, may polyolefins derived from monoolefins having 3 to 5 carbon atoms, and in which a) R4 represents an alkyl or alkenyl group having 10 to 40 carbon atoms or a radical alkoxyalkyl with 1 to 100 alkoxy units and 1 to 30 carbon atoms in the alkyl radical, b) R5 represents a radical of formula OCOR12 or COOR 12, in which R12 represents C1 to C3, and c) the number of carbon atoms of the polyolefin molecules constituting the basis of structural units B3) is between 35 and 350, d) R11 represents hydrogen or methyl, and optionally C) an additional, different copolymer a) and B) based on ethylene and 8-13 mol% of at least one vinyl ester such as vinyl acetate, pr opionato, vinyl butyrate, vinyl hexanoate, vinyl octanoate, vinyl esters of neononanoic and neodecanoic, an ester (C1-C30) -vinílico and / or a (meth) acrylate (C1-C30 ), which has only activity as agents to improve cold flow to middle distillates.