US4485225A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for continuous copolymerization of ethylene and vinyl acetate
Assignee: Kuraray Co Ltd
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Filing: 1983-11-30
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Granted: 1984-11-27
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Expires: 2003-11-30
Abstract
Abstract The invention provides a method of continuously copolymerizing ethylene and vinyl acetate in a solvent in the presence of a radical initiator without causing gel formation.
Inventors
- 👤 Kenji Satoh
- 👤 Kiyoshi Yonezu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:53
CPC Classifications
C; C08; C08F; C08F210/00; C08F210/02; C08F218/00; C08F218/02; C08F218/04; C08F218/08
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
94 words
A method of producing an ethylene and vinyl acetate copolymer having an ethylene content of less than 60 mole % without causing gel formation which comprises continuously copolymerizing ethylene and vinyl acetate in the presence of a methanol solvent using 2,2'-azobis (2,4-dimethyl- 4-methoxyvaleronitrile) as a radical initiator, said solvent concentration being lower than 20 weight %, wherein the copolymerization temperature ranges from about 35° C. to 80° C., the conversion of vinyl acetate is not more than 85% and the average residence time in the polymerization vessel ranges from 1.5 hours to 15 hours.
Claim 2
Independent Claim
94 words
A method of producing an ethylene and vinyl acetate copolymer having an ethylene content of less than 60 mole % without causing gel formation which comprises continuously copolymerizing ethylene and vinyl acetate in the presence of a methanol solvent using 2,2'-azobis (2,4-dimethyl- 4-methoxyvaleronitrile) as a radical initiator, said solvent concentration being lower than 20 weight %, wherein the copolymerization temperature ranges from about 35° C. to 80° C., the conversion of vinyl acetate is not more than 85% and the average residence time in the polymerization vessel ranges from 1.5 hours to 15 hours.
Claim 3
Dependent Claim
36 words
A method of producing an ethylene and vinyl acetate copolymer having an ethylene content of less than 60 mole % without causing gel formation as claimed in claim 1, wherein the radical initiator is 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile).
Claim 4
Independent Claim
131 words
A method of producing a copolymer having ethylene and vinyl acetate as main comonomers and having an ethylene content of less than 60 mole % without causing gel formation which comprises continuously copolymerizing ethylene and vinyl acetate as main comonomers together with a further copolymerizable comonomer of the formula CH.sub.2 CRR' wherein R is a hydrogen atom or a methyl group or a COOR group wherein R is as defined above, in the presence of a methanol solvent using 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile) as a radical initiator, said solvent concentration being lower than 20 weight %, wherein the copolymerization temperature ranges from about 35° C. to 80° C., the conversion of vinyl acetate is not more than 85% and the average residence time in the polymerization vessel ranges from 1.5 hours to 15 hours.
Claim 5
Independent Claim
131 words
A method of producing a copolymer having ethylene and vinyl acetate as main comonomers and having an ethylene content of less than 60 mole % without causing gel formation which comprises continuously copolymerizing ethylene and vinyl acetate as main comonomers together with a further copolymerizable comonomer of the formula CH.sub.2 CRR' wherein R is a hydrogen atom or a methyl group or a COOR group wherein R is as defined above, in the presence of a methanol solvent using 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile) as a radical initiator, said solvent concentration being lower than 20 weight %, wherein the copolymerization temperature ranges from about 35° C. to 80° C., the conversion of vinyl acetate is not more than 85% and the average residence time in the polymerization vessel ranges from 1.5 hours to 15 hours.
Claim 6
Dependent Claim
40 words
A method of producing a copolymer having ethylene and vinyl acetate as main comonomers and having an ethylene content of less than 60 mole % without causing gel formation as claimed in claim 4, wherein the radical initiator is 2,2'-azobis(4-methoxy-2,4-dimathylvaleronitrile)
Claim 7
Dependent Claim
46 words
A method of producing an ethylene and vinyl acetate copolymer having an ethylene content of less than 60 mole % without causing gel formation as claimed in claim 1, wherein the radical initiator is selected form the group consisting of 2,2'-azobis (2,4-dimethyl-4-methoxyvaleronitrile), 2,2'-azobis (2,4,4-trimethylvaleronitrile) and 1,1'-azobis-(cyclooctanecarbonitrile).
Claim 8
Dependent Claim
49 words
A method of producing a copolymer having ethylene and vinyl acetate as main comonomers and having an ethylene content of less than 60 mole % without causing gel formation as claimed in claim 4, wherein the radical initiator is selected from the group consisting of 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile), 2,2'-azobis(2,4,4-trimethylvaleronitrile) and 1,1'-azobis(cyclooctanecarbonitrile).
Claim 9
Dependent Claim
44 words
A method of producing an ethylene and vinyl acetate copolymer having an ethylene content of less than 60 mole % without causing gel formation as claimed in claim 1 wherein the radical initiator is selected from the group consisting of 2,2'-azobis(2,4-dimethyl-4 methoxyvaleronitrile) and 2,2'-azobis(2,4,4-trimethylvaleronitrile).
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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) | 1987-11-27 | 1988-05-28 | 1988-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-11-27 | 1992-05-28 | 1992-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-11-27 | 1996-05-28 | 1996-11-27 | $7700.00 | Window Closed / Lapsed |