Patent CA774987A successfully refreshed from Google Patents.
US5350813A
Expired / Lapsed
US
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Fluid assisted devolatilization
Assignee: Nova Chemicals International SA
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Filing: 1993-05-27
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Granted: 1994-09-27
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Expires: 2013-05-27
Abstract
Abstract A polymer melt may be devolatilized to less than 500, preferably less than 150 ppm of residual volatile material by injecting into the melt an amount of fluid which will condense but not freeze at pressures of less than about 20 mm Hg, in an amount greater than the amount of residual volatile material in the polymer melt, typically not more than about 10 weight % and passing the melt through a zone of pressure of 8 mm of Hg or less at a temperature of from 200° to 350° C.
Inventors
- 👤 John P. Skilbeck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:29
CPC Classifications
C; C08; C08F; C08F6/00; C08F6/001; B; B01; B01D; B01D3/00; B01D3/06; B01D3/34
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
164 words
A process for reducing the amount of residual monomer and solvent to less than 75 parts per million in a polymer or polymer blend, containing less than 1 weight % of such residual monomer, dimer, trimer and solvent, which process comprises: (i) heating and maintaining said polymer or polymer blend at a temperature from 200°-270° C.; (ii) injecting into said polymer or polymer blend an amount of an organic fluid greater than the amount of residual monomer, dimer, trimer and solvent in said polymer or polymer blend but less than 1 weight %, said injection being at temperature of from 200°-270° C. and pressures from 500 to 1500 psi and said organic fluid being selected from the group consisting of C 1-4 alkanols and C 1-4 ketones: and (iii) passing said polymer or polymer blend in the form of strands vertically through a flash chamber devolatilizer maintained at a temperature from 225°-235° C. and which has a pressure maintained at less than 5 torr.
Claim 2
Dependent Claim
164 words
A process for reducing the amount of residual monomer and solvent to less than 75 parts per million in a polymer or polymer blend, containing less than 1 weight % of such residual monomer, dimer, trimer and solvent, which process comprises: (i) heating and maintaining said polymer or polymer blend at a temperature from 200°-270° C.; (ii) injecting into said polymer or polymer blend an amount of an organic fluid greater than the amount of residual monomer, dimer, trimer and solvent in said polymer or polymer blend but less than 1 weight %, said injection being at temperature of from 200°-270° C. and pressures from 500 to 1500 psi and said organic fluid being selected from the group consisting of C 1-4 alkanols and C 1-4 ketones: and (iii) passing said polymer or polymer blend in the form of strands vertically through a flash chamber devolatilizer maintained at a temperature from 225°-235° C. and which has a pressure maintained at less than 5 torr.
Claim 3
Dependent Claim
23 words
The process according to claim 1, wherein said organic fluid is a liquid selected from the group consisting of methanol, ethanol, and acetone.
Claim 4
Dependent Claim
21 words
The process according to claim 2, further comprising depositing said polymer or polymer blend on a distributor within said flash chamber.
Claim 5
Dependent Claim
17 words
The process according to claim 2, wherein the pressure within said flash chamber is below 3 torr.
Claim 6
Dependent Claim
17 words
The process according to claim 3, wherein the pressure within said flash chamber is below 3 torr.
Claim 7
Dependent Claim
154 words
The process according to claim 4, wherein said polymer melt comprises one or more polymers selected from tile group of polymers consisting of: (i) from 100 to 30, weight % of one or more monomers selected from tile group consisting of: C 8-12 vinyl aromatic monomers which are unsubstituted or substituted by a C 1-4 alkyl radical; (ii) from 0 to 70, weight % of one more monomers selected from the group consisting of: C 1-4 alkyl esters of acrylic or methacrylic acid; acrylonitrile and methacrylonitrile; which polymers may be grafted on to from 0 to 40, weight % of one or more rubbery polymers selected from the group consisting of: (iii) one or more C 4-6 conjugated diolefin monomers; and (iv) polymers comprising from 20 to 80, weight % of one or more C 8-12 vinyl aromatic monomers and from 80 to 20, weight % of one or more C 4-6 conjugated diolefins.
Claim 8
Dependent Claim
154 words
The process according to claim 5, wherein said polymer melt comprises one or more polymers selected from the group of polymers consisting of: (i) from 100 to 30, weight % of one or more monomers selected from the group consisting of: C 8-12 vinyl aromatic monomers which are unsubstituted or substituted by a C 1-4 alkyl radical; (ii) from 0 to 70, weight % of one more monomers selected from the group consisting of: C 1-4 alkyl esters of acrylic or methacrylic acid; acrylonitrile and methacrylonitrile; which polymers may be grafted on to from 0 to 40, weight % of one or more rubbery polymers selected from the group consisting of: (iii) one or more C 4-6 conjugated diolefin monomers; and (iv) polymers comprising from 20 to 80, weight % of one or more C 8-12 vinyl aromatic monomers and from 80 to 20, weight % of one or more C 4-6 conjugated diolefins.
Claim 9
Dependent Claim
14 words
The process according to claim 6, wherein said polymer or polymer blend is polystyrene.
Claim 10
Dependent Claim
20 words
The process according to claim 6, wherein said polymer or polymer blend is a blend of polyphenylene oxide and polystyrene.
Claim 11
Dependent Claim
14 words
The process according to claim 7, wherein said polymer or polymer blend is polystyrene.
Claim 12
Dependent Claim
20 words
The process according to claim 7, wherein said polymer or polymer blend is a blend of polyphenylene oxide and polystyrene.
References Cited (Backward Citations)
US3987235A
Cited
US5118388A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-09-26 | 1998-03-28 | 1998-09-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-09-26 | 2002-03-28 | 2002-09-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-09-26 | 2006-03-28 | 2006-09-27 | $7700.00 | Window Closed / Lapsed |