USE OF COPOLYMERS OF ETHYLENE AND/OR PROPYLENE AND VINYLIC ESTERS MODIFIED BY GRAFTING AS DIFUNCTIONAL LUBRICANT AND COLD RESISTANT ADDITIVES FOR LIQUID HYDROCARBONS

摘要

The invention pertains to the synthesis and use of copolymers based on ethylene and/or propylene and vinyl ester(s) which are modified by grafting and are effective for enhancing both the low-temperature resistance and the lubricity of liquid hydrocarbons, more particularly the middle distillates obtained from the distillation of petroleum and crude oils, especially those with a low sulfur content, and relates to a copolymer comprising: a) units derived from ethylene, of formula A -(CH2-CH2)nl- and/or from propylene, of formula A' -((CH3)CH2-CH2)n2-, with n1 + n2 = n ranging from 98 to 643, preferably ranging from 124 to 515; n1 being advantageously equal to n; b) units of formula B: -(CH2-CHOOCR1)m-x- in which R1 represents a linear or branched C1-C15 alkyl group, preferably methyl or propyl, or a C5 to Cl5 branched alkyl group in which the branching is located at any point of the alkyl radical, preferably in position 2 or 3 of the alkyl chain; and preferably selected from the preferred C5-C15 vinyl comonomers, preferably selected from pivalate, isopentanoate, isohexanoate, isononanoate, isodecanoate and/or isotridecanoate, and advantageously 2-ethylhexanoate, neoalkanoates, especially neononanoate, neodecanoate and/or neoundecanoate; with m being from 2 to 105, preferably from 16 to 71, and x being from 0.2 to 105, preferably from 1.6 to 71; c) units of formula C: -(CH2-CHOH)x1- in which x1 is from 0 to 0.30x, preferably xl = 0; d) units of formula D: -(CH2-CHOOCR2)x2- in which x2 is from 0.70x to x, preferably x2 = x, and R2 represents a saturated or unsaturated C8-C24, preferably C14-C20 or else C14 to C18 linear or branched alkyl group, with x = x1 + x2.