| 摘要 |
<p>1307446 Ethylene-propylene copolymers E I DU PONT DE NEMOURS & CO 27 July 1970 [30 July 1969] 36216/70 Heading C3P A process for continuously polymerizing ethylene and propylene in a liquid/vapour phase reaction system in the presence of a diluent and a co-ordination catalyst to produce an elastomer of predetermined composition comprises (a) controlling the reaction mixture temperature by withdrawing a first stream from the vapour phase of the reaction mixture and compressing, cooling and purging it of contaminants before returning it to the reaction mixture at a controlled rate, (b) withdrawing from the liquid phase of the reaction mixture a second stream containing polymer, catalyst residue, unreacted monomers and diluent, (c) inactivating catalyst in, and volatilizing ethylene and propylene and separating polymer from the second stream and recycling the monomers and diluent in a dry state to the reaction mixture, and (d) monitoring the amounts of ethylene and propylene in the second stream following separation of polymer therefrom and regulating the flow of fresh ethylene and propylene to the reaction mixture to maintain their concentrations at a desired level in the liquid phase. Polymerization may be effected in the presence of hydrogen, and preferably ethylene and propylene volatilized from the second stream are continuously dissolved in solvent, remaining after polymer separation and the resulting solution is monitored for ethylene, propylene and hydrogen. The olefins may be copolymerized with a non- conjugated diene, e.g. alkadienes, dicyclopentadiene, alkylene and alkylidene norbornenes, norbornadienes and 1,5-cyolo-octadiene. Suitable solvents are tetrachloroethylene and hexane. Apparatus suitable for carrying out the invention is described and illustrated, and an example describes the copolymerization of ethylene / propylene / 1,4 - hexadiene in tetrachloroethylene in the presence of hydrogen and a catalyst formed from vanadium oxytrichloride and diisobutyl aluminium chloride.</p> |
