Process for the on-line grafting of carboxylic acid and carboxylic acid anhydrides containing an ethylenic unsaturation onto ethylene homopolymers or copolymers and installation for the implementation of this process

US5591410A · kind A · utility

Assignee

• ECP-Enichem Polymeres France S.A. · FR

Inventors

• Joel Audureau · Koumac, FR
• Hacene Mehalla · Essars, FR
• Thierry Pellerin · Lens, FR

Key dates

• Filing date: Jun 7, 1995
• Grant date: Jan 7, 1997
• Expiry date: Jun 7, 2015

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F255/02
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

(I) The (co)polymerisation of ethylene is carried out in at least one reaction zone (R) under high pressure, at 150.degree.-320.degree. C.; (II) the reaction product is routed into a zone (S), under an intermediate pressure P, for separation of the (co)polymer, in the molten state, from the unreacted (co)monomer(s), or the reaction product is routed into a first separation zone (S1), under an intermediate pressure (P1); the (co)polymer issuing from (S1) is then routed into a second separation zone (S2), under a pressure P2<P1; (III) the (co)polymer is routed into a zone (SF), under low pressure, for final separation of the (co)polymer from the residual gases. Let-down zones (D), (D1) and (D2) are provided along the path of the (co)polymer between the zones (S) and (SF), (S1) and (S2), and (S2) and (SF) respectively, the grafting monomer or monomers being introduced on-line, in the path of the (co)polymer, at at least one point located at the level of the zone (D) or at at least one zone (D1, D2). A grafting initiator may be introduced on-line at the same time as the grafting monomer(s) flow, or separately.