Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymerizing in tubular or loop reactor
Patent
1995-06-07
1997-11-04
Weber, Thomas R.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymerizing in tubular or loop reactor
526 65, C08F 234
Patent
active
056840977
ABSTRACT:
A process for producing polyethylene compositions in the presence of a catalytic system of ethylene polymerizing catalyst and cocatalyst in a multistage continuous reaction sequence consisting of successive liquid phase and gas phase polymerizations is disclosed. In the first step of the process, ethylene and optionally hydrogen and comonomer are polymerized in a first loop reactor in a low boiling hydrocarbon medium in the presence of ethylene polymerizing catalyst and cocatalyst. The reaction mixture is then removed and then transferred to a second loop reactor where polymerization is continued by addiing ethylene, hydrogen and optionally inert hydrocarbon, comonomers and cocatalysts. Thereafter, the reaction mixture is removed from the second loop reactor along with an essential part of the reaction medium and transferred to a gas phase reactor where polymerizing is continued in the presence of added ethylene and optionally hydrogen, comonomers and cocatalysts to form an end product. The residence time and reaction temperature being such that the proportion of the ethylene polymer produced in the first loop reactor to the end product of the process is between 1-20%.
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Ahvenainen Antero
Harlin Ali
Palmroos Ari
Sahila Aimo
Takakarhu Jouni
Borealis Polymers OY
Weber Thomas R.
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