Process of producing ethylene polymer blends in gas phase
US5405901A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 6, 1994 |
| Grant date | Apr 11, 1995 |
| Priority date | — |
| Expiry date | Jul 6, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F2410/01
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A gas phase process for the production of a polyethylene blend comprising contacting ethylene and at least one alpha-olefin comonomer having 3 to 8 carbon atoms with a magnesium/titanium based catalyst system including an activator and a cocatalyst in each of two fluidized bed reactors connected in series, under polymerization conditions, with the provisos that: PA1 (a) the mixture of ethylene copolymer matrix and active catalyst formed in the first reactor in the series is transferred to the second reactor in the series; PA1 (b) other than the active catalyst referred to in proviso (a) and the cocatalyst referred to in proviso (e), no additional catalyst is introduced into the second reactor; PA1 (c) in the first reactor in which a low melt index copolymer is made: PA2 (1) the alpha-olefin is present in a ratio of about 0.01 to about 0.4 mole of alpha-olefin per mole of ethylene; PA2 (2) optionally, hydrogen is present in a ratio of about 0.001 to about 0.3 moles of hydrogen per mole of ethylene; and PA2 (3) the ethylene partial pressure is at least about 40 pounds per square inch; and PA1 (d) in the second reactor in which a high melt index copolymer is made: PA2 (1) the alpha-ol…
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