Patent US3969470A successfully refreshed from Google Patents.
US3969470A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for recycling hydrogen when making blends of olefin copolymers
Assignee: EIDP Inc
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Filing: 1975-04-21
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Granted: 1976-07-13
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Expires: 1995-04-21
Abstract
Abstract A continuous process for recycling hydrogen for reuse in making blends of olefin copolymers of high and low molecular weights which comprises copolymerizing ethylene with at least one higher olefin monomer in a solvent in separate reactors in the presence of a coordination catalyst, at least one, but not all, of said reactors containing hydrogen in an amount sufficient to produce low molecular weight copolymer. The resulting solutions of high and low molecular weight copolymers are mixed, unreacted monomers and hydrogen are flashed from the mixture, and the copolymer blend is isolated from the unflashed residue. The flashed gaseous unreacted monomers and hydrogen are circulated together through a staged absorption column under superatmospheric pressure and simultaneously solvent is passed through said column in order to absorb monomer in the solvent and thus separate unabsorbable hydrogen gas from the monomers for recycle to a polymerization reactor in the system for making low molecular weight copolymer component.
Inventors
- 👤 Phillip Poliner Spiegelman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:03
CPC Classifications
C; C08; C08F; C08F210/00; C08F210/16; C08F210/18; Y; Y10; Y10S; Y10S525/00; Y10S525/91; Y10S526/00; Y10S526/905
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
172 words
In a continuous process for making blends of high and low molecular weight copolymers and recycling the chain-transfer agent gaseous hydrogen for reuse in the process, said process comprising polymerizing ethylene and at least one higher olefin monomer in a solvent for the monomers in separate polymerization reactors in the presence of a coordination catalyst, at least one, but not all, of said reactors containing the chain-transfer agent hydrogen in an amount sufficient to produce low molecular weight copolymer, mixing the resulting solution of high and low molecular weight copolymers, flashing unreacted monomers and hydrogen from the mixture and isolating the blend of high and low molecular weight copolymers and solvent from the unflashed residue, the improvement which comprises circulating the flashed gaseous unreacted monomers and hydrogen together through a staged absorption column and simultaneously passing said solvent through said column to absorb monomer gas in the solvent and thus separate unabsorbable hydrogen gas from monomers and recycling hydrogen in the system to a polymerization reactor for making low molecular weight copolymer.
Claim 2
Dependent Claim
172 words
In a continuous process for making blends of high and low molecular weight copolymers and recycling the chain-transfer agent gaseous hydrogen for reuse in the process, said process comprising polymerizing ethylene and at least one higher olefin monomer in a solvent for the monomers in separate polymerization reactors in the presence of a coordination catalyst, at least one, but not all, of said reactors containing the chain-transfer agent hydrogen in an amount sufficient to produce low molecular weight copolymer, mixing the resulting solution of high and low molecular weight copolymers, flashing unreacted monomers and hydrogen from the mixture and isolating the blend of high and low molecular weight copolymers and solvent from the unflashed residue, the improvement which comprises circulating the flashed gaseous unreacted monomers and hydrogen together through a staged absorption column and simultaneously passing said solvent through said column to absorb monomer gas in the solvent and thus separate unabsorbable hydrogen gas from monomers and recycling hydrogen in the system to a polymerization reactor for making low molecular weight copolymer.
Claim 3
Dependent Claim
23 words
A process of claim 1 wherein gaseous hydrogen and unreacted monomer are passed countercurrent to the flow of solvent in the absorption column.
Claim 4
Dependent Claim
11 words
A process of claim 2 wherein the solvent is a hydrocarbon.
Claim 5
Dependent Claim
10 words
A process of claim 2 wherein the solvent is hexane.
Claim 6
Dependent Claim
11 words
A process of claim 2 wherein the solvent contains unreacted monomer.
Claim 7
Dependent Claim
11 words
A process of claim 2 wherein the coordination catalyst contains vanadium.
Claim 8
Dependent Claim
11 words
A process of claim 2 wherein the higher olefin is propylene.
Claim 9
Dependent Claim
14 words
A process of claim 7 wherein the copolymer contains units of a nonconjugated diene.
Claim 10
Dependent Claim
11 words
A process of claim 8 wherein the nonconjugated diene is 1,4-hexadiene.
Claim 11
Dependent Claim
12 words
A process of claim 8 wherein the nonconjugated diene is ethylene norbornene.
Claim 12
Dependent Claim
11 words
A process of claim 2 wherein two polymerization reactors are used.
Claim 13
Dependent Claim
13 words
A process of claim 2 wherein two polymerization reactors are used in series.
Claim 14
Dependent Claim
21 words
A process of claim 2 wherein the pressure employed in the absorption column is about from 2 to 40 atmospheres (absolute).
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-07-13 | 1980-01-12 | 1980-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-13 | 1984-01-12 | 1984-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-13 | 1988-01-12 | 1988-07-13 | $7700.00 | Window Closed / Lapsed |