Patent US4740551A successfully refreshed from Google Patents.
US4740551A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multistage copolymerization process
Assignee: Union Carbide Chemicals and Plastics Technology LLC
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Filing: 1986-06-18
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Granted: 1988-04-26
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Expires: 2006-06-18
Abstract
Abstract The present invention relates to a multistage, continuous process for the preparation of propylene-ethylene impact copolymers comprising the use of a plug flow pipeline reactor for homopolymerizing propylene, a gas-phase fluidized bed reactor for additional propylene homopolymerization, and a gas-phase fluidized bed reactor for propylene/ethylene copolymerization.
Inventors
- 👤 E. Gordon Foster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:41
CPC Classifications
C; C08; C08F; C08F297/00; C08F297/06; C08F297/08; C08F297/083; B; B01; B01J; B01J19/00; B01J19/24; B01J19/2415; B01J19/242; B01J19/2435; B01J3/00; B01J3/008; B01J8/00; B01J8/18; B01J8/24; B01J8/26; C08F10/00; C08F10/04; C08F10/06; B01J2219/00; B01J2219/00049; B01J2219/00051; B01J2219/00121; B01J2219/0013; B01J2219/00171
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
127 words
A continuous process for the preparation of propylene-ethylene impact copolymers comprising: (a) homopolymerizing propylene in a plug flow pipeline reactor in the presence of a liquid medium or high density supercritical phase comprising propylene monomer as a major constituent and in the presence of magnesium chloride and titanium-containing catalyst particles, resulting in a homopolymer slurry; (b) transferring said homopolymer slurry to a gas-phase fluidized bed homopolymer reactor and homopolymerizing additional propylene; (c) removing a stream of propylene homopolymer particles from said gas-phase fluidized bed homopolymer reactor and transferring the stream to a gas-phase fluidized bed copolymer reactor; (d) copolymerizing ethylene and propylene in said copolymer reactor, resulting in a propylene-ethylene impact copolymer; and (e) removing said propylene-ethylene impact copolymer as a product stream from said copolymer reactor.
Claim 2
Dependent Claim
127 words
A continuous process for the preparation of propylene-ethylene impact copolymers comprising: (a) homopolymerizing propylene in a plug flow pipeline reactor in the presence of a liquid medium or high density supercritical phase comprising propylene monomer as a major constituent and in the presence of magnesium chloride and titanium-containing catalyst particles, resulting in a homopolymer slurry; (b) transferring said homopolymer slurry to a gas-phase fluidized bed homopolymer reactor and homopolymerizing additional propylene; (c) removing a stream of propylene homopolymer particles from said gas-phase fluidized bed homopolymer reactor and transferring the stream to a gas-phase fluidized bed copolymer reactor; (d) copolymerizing ethylene and propylene in said copolymer reactor, resulting in a propylene-ethylene impact copolymer; and (e) removing said propylene-ethylene impact copolymer as a product stream from said copolymer reactor.
Claim 3
Dependent Claim
28 words
The process of claim 1 wherein a portion of propylene monomer vaporized in the gas-phase fluidized bed homopolymer reactor is removed, condensed and recycled to said pipeline reactor.
Claim 4
Dependent Claim
26 words
The process of claim 1 wherein between 50 and 95 weight percent of total propylene homopolymer in said product stream is produced in said pipeline reactor.
Claim 5
Dependent Claim
24 words
The process of claim 1 wherein the amount of propylene polymerized in said pipeline reactor is between 5,000 and 20,000 grams per gram catalyst.
Claim 6
Dependent Claim
21 words
The process of claim 1 wherein said pipeline reactor has a ratio of length to inside diameter of greater than 500:1.
Claim 7
Dependent Claim
28 words
The process of claim 5 wherein said pipeline reactor has an inside diameter of between 0.5 and 6 inches and a length of between 1,000 and 10,000 feet.
Claim 8
Dependent Claim
26 words
The process of claim 1 wherein the ethylene-propylene copolymer portion of said impact copolymer comprises 10 to 20 weight percent of the total impact copolymer composition.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-04-26 | 1991-10-26 | 1992-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-26 | 1995-10-26 | 1996-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-26 | 1999-10-26 | 2000-04-26 | $7700.00 | Window Closed / Lapsed |