Patent US4002811A successfully refreshed from Google Patents.
US4002811A
Expired / Lapsed
US
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Production of uniform copolymer of acrylonitrile and aromatic olefines
Assignee: Imperial Chemical Industries Ltd
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Filing: 1974-12-13
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Granted: 1977-01-11
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Expires: 1994-12-13
Abstract
Abstract Copolymers of acrylonitrile and conjugated aromatic olefines, such as styrene, containing 50-95% molar of acrylonitrile are made using an aqueous suspension process in which polyvinyl pyrrolidone is used as suspension agent.
Inventors
- 👤 Brian Norman Hendy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:28
CPC Classifications
C; C08; C08F; C08F20/00; C08F20/02; C08F20/42; C08F20/44; C08F2/00; C08F2/12; C08F2/16; C08L; C08L33/00; C08L33/18; C08L33/20; Y; Y10; Y10S; Y10S526/00; Y10S526/909; Y10S526/91
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
95 words
A suspension polymerization process for the batchwise production of a uniform copolymer of acrylonitrile and at least one conjugated aromatic olefine having a faster reaction rate selected from the group consisting of styrene, α-methyl styrene and mixtures thereof containing 50 to 95% molar of acrylonitrile units which method comprises polymerising the monomers in aqueous suspension and feeding a portion of at least the faster reacting aromatic olefine to the reaction mixture so as to produce said uniform copolymer wherein polyvinyl pyrrolidone having a Fikentscher K value of at least 60 is employed as suspension agent.
Claim 2
Dependent Claim
95 words
A suspension polymerization process for the batchwise production of a uniform copolymer of acrylonitrile and at least one conjugated aromatic olefine having a faster reaction rate selected from the group consisting of styrene, α-methyl styrene and mixtures thereof containing 50 to 95% molar of acrylonitrile units which method comprises polymerising the monomers in aqueous suspension and feeding a portion of at least the faster reacting aromatic olefine to the reaction mixture so as to produce said uniform copolymer wherein polyvinyl pyrrolidone having a Fikentscher K value of at least 60 is employed as suspension agent.
Claim 3
Dependent Claim
93 words
A method according to claim 1 which comprises removing heat from the reaction vessel by heat exchanging with a fluid whereby the rate of production of heat in the copolymer formation may be determined and feeding at least a proportion of the faster reacting aromatic olefine to the reaction mixture at a rate dependent on the rate of production of heat in the copolymer formation so that the total amount of monomer feed to the reaction mixture up to any given time corresponds to the total integrated heat produced up to that time.
Claim 4
Dependent Claim
18 words
A method according to claim 1 wherein the polyvinyl pyrrolidone has a K value of at least 80.
Claim 5
Dependent Claim
25 words
A method according to claim 1 wherein the quantities of comonomers employed are selected to provide a copolymer having 86 to 93% molar acrylonitrile units.
Claim 6
Dependent Claim
31 words
A method according to claim 1 employing a chain-transfer agent selected from lauryl mercaptan, butyl mercaptan, n-octyl mercaptan and limonene mercaptan, pentraerythritol tetra (3-thiopropionate), iso-octyl thioglycollate, and trimethylol propane tri (3-thiopropionate).
References Cited (Backward Citations)
US2890199A
Cited
US2895938A
Cited
US3459719A
Cited
GB1185306A
Cited
GB1197721A
Cited
GB1327095A
Cited
US3828013A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-01-11 | 1980-07-12 | 1981-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-11 | 1984-07-12 | 1985-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-11 | 1988-07-12 | 1989-01-11 | $7700.00 | Window Closed / Lapsed |