Method for preparing branched copolymers by ethylene with unsaturated silicone monomers

Branched copolymers of ethylene with unsaturated silicone monomers, useful as water-repellent coatings, having the general formula R1CH=CHSiRm2Rn3(OR4)p, wherein R1 is H or an aliphatic radical having the number of carbon atoms from 1 to 3; R2 is a saturated aliphatic radical with from 1 to 4 carbon atoms; R3 is phenyl; R4 is a saturated aliphatic radical having from 1 to 10 carbon atoms or an aryl having no more than 2 aromatic rings; m is from 0 to 2, when R1 = H, and from 1 to 3, when R1 is a saturated aliphatic radical; n is from 0 to 3; p is from 0 to 2; and m + n + p = 3; can be prepared by copolymerization of ethylene with unsaturated silicone monomers of the above formula, wherein the reaction mixture contains from 0.5 to 85 molar per cent of the silicone monomer, at pressures from 150 to 3500 atm and temperatures of from 40 DEG to 300 DEG C in the presence of free-radical polymerization.