US4754011A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Emulsion copolymers of meta- or para-isopropenyl-alpha, alpha-di-methylbenzylisocyanates
Assignee: Wyeth Holdings LLC
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Filing: 1983-12-21
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Granted: 1988-06-28
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Expires: 2003-12-21
Abstract
Abstract A method of making a copolymer of meta- or para-isopropenyl- α,α-dimethylbenzylisocyanate and at least one other ethylenically unsaturated comonomer polymerizable therewith, comprising polymerizing the meta- or para-isopropenyl- α,α-dimethylbenzylisocyanate and at least one other ethylenically unsaturated comonomer in an aqueous emulsion in the presence of a free-radical polymerization initiator and a chain transfer agent to control molecular weight. Also disclosed are methods of breaking the aqueous emulsion after polymerization is completed by either adding a salt, e.g., aluminum sulfate, or by freezing the emulsion followed by thawing to yield the copolymer as a mechanically separable solid phase of a two-phase liquid-solid mixture.
Inventors
- 👤 Robin W. Dexter
- 👤 Peter S. Forgione
- 👤 John A. Sedlak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:54
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/70; C08G18/72; C08G18/728; C08F; C08F212/00; C08F212/02; C08F212/04; C08F212/14; C08F212/26; C08F6/00; C08F6/14; C08F6/22
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
51 words
A method of making a copolymer of meta- or para-isopropenyl-α,α-dimethylbenzylisocyanate and at least one other ethylenically unsaturated comonomer polymerizable therewith, comprising polymerizing said meta- or para-isopropenyl-α,α-dimethylbenzylisocyanate and at least one other ethylenically unsaturated comonomer in an aqueous emulsion in the presence of a free-radical polymerization initiator and a chain transfer agent.
Claim 2
Independent Claim
51 words
A method of making a copolymer of meta- or para-isopropenyl-α,α-dimethylbenzylisocyanate and at least one other ethylenically unsaturated comonomer polymerizable therewith, comprising polymerizing said meta- or para-isopropenyl-α,α-dimethylbenzylisocyanate and at least one other ethylenically unsaturated comonomer in an aqueous emulsion in the presence of a free-radical polymerization initiator and a chain transfer agent.
Claim 3
Dependent Claim
35 words
A method according to claim 1, wherein said at least one ethylenically unsaturated comonomer is selected from the group consisting of butyl acrylate, methyl acrylate, methyl methacrylate, ethyl acrylate, styrene, α-methylstyrene, p-methyl- α-methylstyrene, and p-methylstyrene.
Claim 4
Dependent Claim
47 words
A method according to claim 1 wherein said copolymer contains from about 5 to about 80 mole percent repeating units derived from meta- or para-isopropenyl- α,α-dimethylbenzylisocyanate and from about 20 to about 95 mole percent repeating units derived from said at least one other ethylenically unsaturated comonomer.
Claim 5
Dependent Claim
20 words
A method according to claim 1 wherein said free-radical polymerization initiator is an admixture of potassium persulfate and sodium metabisulphite.
Claim 6
Dependent Claim
16 words
A method according to claim 1 wherein said chain transfer agent is a water insoluble mercaptan.
Claim 7
Dependent Claim
24 words
A method according to claim 1 wherein said polymerization is carried out at a temperature of from about 25° C. to about 60° C.
Claim 8
Dependent Claim
23 words
A method according to claim 1 wherein said chain transfer agent is selected from the group consisting of dodecyl mercaptan and n-octyl thiol.
Claim 9
Dependent Claim
34 words
A process according to claim 7 wherein said chain transfer agent is present in said polymerization in an amount of from about 0.2 to about 10 mole percent based on the weight of monomer.
Claim 10
Dependent Claim
127 words
A method according to claim 1 for forming a substantially homogeneous copolymer of meta- or para-isopropenyl-α, α-dimethylbenzylisocyanate, and at least one other ethylenically unsaturated comonomer polymerizable therewith selected from the group consisting of butyl acrylate, methyl acrylate, methyl methacrylate, ethyl acrylate, styrene, α-methylstyrene, p-methyl-α-methylstyrene and p-methylstyrene, comprising: (a) forming a reaction volume comprising water, free-radical polymerization initiator, chain transfer agent and such one of said other ethylenically unsaturated comonomers to be incorporated into said copolymer as has the lowest reactivity thereof; and (b) adding meta- or para-isopropenyl-α,α-dimethylbenzylisocyanate and other remaining comonomers to be incorporated into said copolymer continuously to said reaction volume under emulsion polymerization reaction conditions while maintaining a constant monomeric composition in said reaction volume, to form said copolymer with a substantially homogeneous polymeric composition.
Claim 11
Dependent Claim
50 words
A method according to claim 1, further including isolating said copolymer from said aqueous emulsion after polymerization has proceeded to a desired extent, comprising adding to said aqueous emulsion an aqueous solution of a salt selected from the group consisting of calcium chloride, sodium chloride, aluminum sulfate, and sodium sulfate.
Claim 12
Dependent Claim
71 words
A method according to claim 1, further including isolating said copolymer from said aqueous emulsion after polymerization has proceeded to a desired extent, comprising: (a) freezing said aqueous emulsion to a frozen solid to thereby break said aqueous emulsion, (b) thawing said frozen solid to yield a two-phase mixture comprising a reliquified aqueous phase and said copolymer as a solid phase, and (c) separating said copolymer from said reliquified aqueous phase.
Claim 13
Dependent Claim
35 words
according to claim 11, wherein said copolymer is separated in step (c) by filtration of said two-phase mixture and thereafter is vacuum dried at a temperature of from about 25° C. to about 40° C.
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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) | 1991-06-28 | 1991-12-28 | 1992-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-28 | 1995-12-28 | 1996-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-28 | 1999-12-28 | 2000-06-28 | $7700.00 | Window Closed / Lapsed |