US4048411A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of copolymers of ethylene
Assignee: BASF SE
•
Filing: 1976-05-19
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Granted: 1977-09-13
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Expires: 1996-05-19
Abstract
Abstract A process for the manufacture of copolymers of ethylene with vinyl acetate at pressures above 800 atmospheres and at from 150° to 350° C, using mean residence times of up to at most 100 seconds. The reaction mixture obtained from the polymerization is kept for from 2 to 10 minutes at from 150° to 250° C under a pressure below 500 atmospheres. Homogeneous ethylene/vinyl acetate copolymers are obtained without the formation of substantial amounts of free acetic acid by decomposition of the vinyl acetate.
Inventors
- 👤 Franz Georg Mietzner
- 👤 Klaus Pfleger
- 👤 Hans Gropper
- 👤 Oskar Buechner
- 👤 Klaus Boettcher
- 👤 Wieland Zacher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 04:58
CPC Classifications
C; C08; C08F; C08F210/00; C08F210/02; C08F6/00; C08F6/26
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
141 words
A process for the manufacture of an ethylene copolymer which contains up to 30 percent by weight of copolymerized units of vinyl acetate by copolymerization of ethylene and vinyl acetate in a tubular reactor at pressures above 800 atmospheres and at from 150° to 350° C with a mean residence time of at most 100 seconds, wherein the reaction mixture obtained after the polymerization is passed, after leaving the reaction zone, through a cooling zone which is at a pressure below 500 atmospheres and at from 150° to 250° C, into a high-pressure product isolation zone which is immediately downstream from the cooling zone, the pressure in said isolation zone being the same as in said cooling zone, the mean residence time of the reaction product in the cooling zone and product isolation zone together being from 2 to 10 minutes.
Claim 2
Dependent Claim
141 words
A process for the manufacture of an ethylene copolymer which contains up to 30 percent by weight of copolymerized units of vinyl acetate by copolymerization of ethylene and vinyl acetate in a tubular reactor at pressures above 800 atmospheres and at from 150° to 350° C with a mean residence time of at most 100 seconds, wherein the reaction mixture obtained after the polymerization is passed, after leaving the reaction zone, through a cooling zone which is at a pressure below 500 atmospheres and at from 150° to 250° C, into a high-pressure product isolation zone which is immediately downstream from the cooling zone, the pressure in said isolation zone being the same as in said cooling zone, the mean residence time of the reaction product in the cooling zone and product isolation zone together being from 2 to 10 minutes.
Claim 3
Dependent Claim
33 words
A process as set forth in claim 1, wherein the temperature in the cooling zone and in the high-pressure product isolation zone which is immediately downstream therefrom is from 200° to 235° C.
Claim 4
Dependent Claim
28 words
A process as set forth in claim 2, wherein the temperature of the reaction mixture in the high-pressure product isolation zone is kept constant to ± 2° C.
Claim 5
Dependent Claim
28 words
A process as set forth in claim 1, wherein the copolymerization is carried out continuously in a tubular polymerization apparatus at a pressure of 800 to 300 atmospheres.
Claim 6
Dependent Claim
46 words
A process as set forth in claim 1, wherein copolymerization is carried out in the presence of an ester of acrylic, methacrylic, fumaric or maleic acid or a vinyl ester of a saturated carboxylic acid of 3 to 8 carbon atoms, whereby a terpolymer is produced.
Claim 7
Dependent Claim
17 words
A process as set forth in claim 1, wherein the copolymerization is carried out above 280° C.
References Cited (Backward Citations)
US3551397A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-09-12 | 1981-03-14 | 1981-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-12 | 1985-03-14 | 1985-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-12 | 1989-03-14 | 1989-09-13 | $7700.00 | Window Closed / Lapsed |