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US 4,059,720 AGranted
Process for the production of polyethylene having molecular weights above 500,000
AssigneeRuhrchemie Aktiengesellschaft
InventorsHelmut Kolling, Friedrich Rappen, Nikolaus Geiser
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Abstract
A process is described wherein polyethylenes having molecular weights greater than 500,000 are prepared and in which the formation of polymer film and lumps in the polymerization reactor is virtually eliminated. The process comprises polymerizing ethylene in the presence of a solvent, a titanium (III) halide/aluminum alkyl catalyst and a mono-or polyhydric alcohol, the ethylene having an oxygen content of less than 5 ppm.
Claims4
A process for preparing polyethylene having a viscosimetrically determined molecular weight greater than about 500,000, said process comprising the steps of:
- A. reducing a titanium (IV) halide with an aluminum alkyl compound of the formula AlR.sub.3 or AlXR.sub.2, wherein R is an alkyl radical having 2 to 10 carbon atoms and X is halogen whereby an activated titanium (III) halide is formed, and
- B. polymerizing ethylene having an oxygen content of less than 1 ppm. in the presence of
- a. a hydrocarbon solvent having a boiling point in the range of 80.degree. C. - 200.degree. C., said solvent having been pre-purified by hydrogenation,
- b. a catalyst comprising said activated titanium (III) halide and an aluminum alkyl compound, in a respective molar ratio of 1:0.2 to 1:5, said aluminum compound being of the formula AlR.sub.3 or AlXR.sub.2, wherein R is an alkyl radical having 2 to 10 carbon atoms and X is halogen, and
- c. a mono - or polyhydric alcohol having 2 - 5 carbon atoms in an amount of 2 to 10 moles per kg. of catalyst;
- said polymerizing being conducted at a pressure of 1 to 100 atmospheres at a temperature of 30.degree. C. to 100.degree. C.
3 more elements
Dependencies are inferred from the claim text.