EP0041796A2
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EP
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Improvement in multi-step gas-phase polymerization of olefins
Assignee: Mitsui Chemicals Inc
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Filing: 1981-05-27
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Granted: —
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Expires: 2001-05-27
Abstract
Abstract A process for polymerizing olefins in the gaseous phase in separate first and second gas-phase polymerization zones in the presence of a catalyst comprising a transition metal catalyst component and an organometallic compound of a metal of Groups I to H1 of the periodic table and of hydrogen gas while feeding the catalyst-containing polymer formed in the first zone to the second zone through a feed passage, wherein ( i) a dilution zone is provided in the feed passage for diluting a feed flow from the first zone, which feed flow comprises a mixture of polymer, catalyst, olefin gas and hydrogen gas, with a fresh supply of olefin gas, (ii) a part of the gas phase in said feed flow diluted in the dilution zone is recycled to the first zone, and the remainder is fed into the second zone, and (iii) in the second zone, the hydrogen to olefin mole ratio is maintained lower than that in the first zone.
Inventors
- 👤 Yoshinori Morita
- 👤 Akifumi Kato
- 👤 Ryoichi Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 16:12
CPC Classifications
C; C08; C08F; C08F10/00; B; B01; B01J; B01J8/00; B01J8/18; B01J8/24; B01J8/26; C08F4/00; C08F4/42; C08F4/44; C08F4/60; C08F4/62; Y; Y10; Y10S; Y10S526/00; Y10S526/901; Y10S526/905
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
189 words
A process for polymerizing olefins in the gaseous phase in a first gas-phase polymerization zone and a second gas-phase polymerization zone, which are provided independently from each other, in the presence of a catalyst composed of a transition metal catalyst component and an organometallic compound of a metal of Groups I to III of the periodic table and in the co-presence of hydrogen gas while feeding the catalyst-containing polymer formed in the first zone to the second zone; characterised by (i) providing in a feed passage for feeding a feed flow, which feed flow comprises a mixture of polymer, catalyst, olefin gas and hydrogen gas, from the first gas-phase polymerization zone to the second gas-phase polymerization zone a dilution zone for diluting said feed flow with a fresh supply of olefin gas, (ii) recycling a part of the gas phase in said feed flow diluted in the dilution zone to the first gas-phase polymerization zone, and feeding the remainder into the second gas-phase polymerization zone, and (iii) maintaining in the second gas-phase polymerization zone a hydrogen to olefin mole ratio lower than that in the first gas-phase polymerization zone.
Claim 2
Dependent Claim
189 words
A process for polymerizing olefins in the gaseous phase in a first gas-phase polymerization zone and a second gas-phase polymerization zone, which are provided independently from each other, in the presence of a catalyst composed of a transition metal catalyst component and an organometallic compound of a metal of Groups I to III of the periodic table and in the co-presence of hydrogen gas while feeding the catalyst-containing polymer formed in the first zone to the second zone; characterised by (i) providing in a feed passage for feeding a feed flow, which feed flow comprises a mixture of polymer, catalyst, olefin gas and hydrogen gas, from the first gas-phase polymerization zone to the second gas-phase polymerization zone a dilution zone for diluting said feed flow with a fresh supply of olefin gas, (ii) recycling a part of the gas phase in said feed flow diluted in the dilution zone to the first gas-phase polymerization zone, and feeding the remainder into the second gas-phase polymerization zone, and (iii) maintaining in the second gas-phase polymerization zone a hydrogen to olefin mole ratio lower than that in the first gas-phase polymerization zone.
Claim 3
Dependent Claim
45 words
A process according to claim 1 wherein the amount of the olefin gas freshly supplied to the dilution zone is such as to dilute the gas phase in the polymer feed flow from the first gas-phase polymerization zone to 1.5 to 200 times its volume.
Claim 4
Dependent Claim
37 words
A process according to claim 1 or 2 wherein the amount of the hydrogen gas in the first gas-phase polymerization zone and the second gas-phase polymerization zone is 0.001 to 20 moles per mole of the olefin.
Claim 5
Dependent Claim
38 words
A process according to claim 1, 2 or 3 wherein the multi-step gas-phase polymerization is carried out at a temperature of from room temperature to 130°C and a pressure of from atmospheric pressure to 150 kg/cm 2 .G.
Claim 6
Dependent Claim
35 words
A process according to any one of the preceding claims wherein the hydrogen to olefin mole ratio in the second gas-phase polymerization zone is 0.001 to 0.7 times that in the first gas-phase polymerization zone.
Claim 7
Dependent Claim
53 words
A process according to any one of the preceding claims wherein the catalyst is composed of a highly active transition metal catalyst component capable of forming at least 5,000 g, per millimole of transition metal, of an olefin polymer under the polymerization conditions in the first gas-phase polymerization zone, and an organoaluminum compound.
Claim 8
Dependent Claim
20 words
A process according to claim 6 wherein the highly active transition metal catalyst component consists essentially of titanium,magnesium and halogen.
Claim 9
Dependent Claim
71 words
A process according to any one of the preceding claims wherein per liter of the volume of the fluidized bed of each gas-phase polymerization zone, the amount of the transition metal catalyst component is 0.0005 to 1 millimole as transition metal atom, and the amount of the organometallic compound is such that the atomic ratio of the metal of the organometallic compound to the transition metal is from 1:1 to 2,000:1.
References Cited (Backward Citations)
No citation records indexed.
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