Patent US4076919A successfully refreshed from Google Patents.
US4076919A
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Manufacture of ethylene polymers in a two-zone tubular reactor at pressure above 500 bars
Assignee: BASF SE
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Filing: 1976-11-15
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Granted: 1978-02-28
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Expires: 1996-11-15
Abstract
Abstract Ethylene polymers are manufactured in a tubular reactor under high pressure and at high temperatures in the presence of polymerization initiators. The polymerization is carried out in two different zones of the reactor, a mixture of ethylene, oxygen and regulator being fed into the first zone and a co-initiator having a half-life temperature, measured in benzene, of above 140 DEG C being additionally fed into the second zone. The co-initiator may be a peroxide or a hydroperoxide. The melt index, or the haze and gloss of a film produced from the resulting ethylene polymer, can be varied advantageously through the choice of the co-initiator.
Inventors
- 👤 Friedrich Urban
- 👤 Oskar Buechner
- 👤 Ulrich Hartig
- 👤 Hans Gropper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 04:28
CPC Classifications
C; C08; C08F; C08F10/00; C08F10/02
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
127 words
A process for the manufacture of an ethylene polymer by homopolymerization of ethylene or copolymerization of ethylene with a copolymerizable comonomer, in a continuously operated tubular polymerization system at a pressure of from 500 to 5,000 bars and at a temperature of from 50° to 450° C, in the presence of a polymerization initiator which generates free radicals, by feeding a mixture of ethylene, oxygen and regulator, with or without comonomer, into the polymerization system at its inlet and at the same time at a second point downstream from the inlet along the polymerization system where the reaction temperature reaches a maximum, wherein a co-initiator which has a half-life temperature, measured in benzene, of above 140° C is additionally fed in exclusively at the second feed point.
Claim 2
Dependent Claim
127 words
A process for the manufacture of an ethylene polymer by homopolymerization of ethylene or copolymerization of ethylene with a copolymerizable comonomer, in a continuously operated tubular polymerization system at a pressure of from 500 to 5,000 bars and at a temperature of from 50° to 450° C, in the presence of a polymerization initiator which generates free radicals, by feeding a mixture of ethylene, oxygen and regulator, with or without comonomer, into the polymerization system at its inlet and at the same time at a second point downstream from the inlet along the polymerization system where the reaction temperature reaches a maximum, wherein a co-initiator which has a half-life temperature, measured in benzene, of above 140° C is additionally fed in exclusively at the second feed point.
Claim 3
Dependent Claim
38 words
A process as claimed in claim 1, wherein the concentration of the co-initiator fed in at the second point is from 0.2 to 20 mole ppm, based on the total amount of ethylene fed into the polymerization system.
Claim 4
Dependent Claim
13 words
A process as claimed in claim 1, wherein the co-initiator is a peroxide.
Claim 5
Dependent Claim
13 words
A process as claimed in claim 1, wherein the co-initiator is a hydroperoxide.
Claim 6
Dependent Claim
17 words
A process as claimed in claim 1, wherein the co-initiator is a mixture of peroxide and hydroperoxide.
References Cited (Backward Citations)
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US3334081A
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US3293233A
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US3546189A
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US3657212A
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US3702845A
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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) | 1981-02-27 | 1981-08-29 | 1982-02-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-27 | 1985-08-29 | 1986-02-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-27 | 1989-08-29 | 1990-02-28 | $7700.00 | Window Closed / Lapsed |