Process for grafting ethylenically unsaturated carboxylic acids and acid anhydrides onto homo- or copolymers of ethylene on-line and installation for use of the process

摘要

(I) Ethylene (co)polymerisation is conducted in at least one reaction zone (R) at high pressure, at 150-320 DEG C; (II) The reaction product is routed into a zone (S) at an intermediate pressure P, for separating the molten (co)polymer from the unreacted (co)monomer(s), or the reacted product of the reaction is routed into a 1st zone, or the reaction product is routed into a 1st separating zone (S1) at an intermediate pressure P1; the (co)polymer originating from (S1) is then routed into a 2nd separating zone (S2), at a pressure P2 < P1; (III) the (co)polymer is routed into a zone (SF) at low pressure, for final separation of the (co)polymer from the residual gases. Decompression zones (D), (D1) and (D2) are arranged on the route of the (co)polymer between the zones (S) and (SF), (S1) and (S2), and (S2) and (SF) respectively, grafting monomer(s) being introduced into the line, onto the route of the (co)polymer, at at least one point situated at the zone (D) or at at least one zone (D1, D2). A grafting initiator may be introduced into the line at the same time as the stream of grafting monomer(s), or separately.