US4587330A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of polymer solutions
Assignee: Atlantic Richfield Co
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Filing: 1985-02-22
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Granted: 1986-05-06
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Expires: 2005-02-22
Abstract
Abstract Cloudy material in organic diluent solutions of polymers prepared by anionic polymerization with a lithium initiator is removed by treating the polymer solutions resulting from the polymerization with boric acid, separating the solid material from the solutions, and isolating the polymer.
Inventors
- 👤 David R. Warfel
- 👤 Harold L. Nicholson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:52
CPC Classifications
C; C08; C08F; C08F6/00; C08F6/02
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
75 words
A method of purifying a polymer prepared by anionic polymerization in an organic diluent in the presence of a lithium initiator, comprising (a) contacting the polymer solution resulting from the polymerization with boric acid, in an amount of at least about 3 wt. % based on polymer weight, to form a liquid phase and a solid phase; (b) separating the solid phase from the liquid phase, and (c) isolating the polymer from the liquid phase.
Claim 2
Independent Claim
75 words
A method of purifying a polymer prepared by anionic polymerization in an organic diluent in the presence of a lithium initiator, comprising (a) contacting the polymer solution resulting from the polymerization with boric acid, in an amount of at least about 3 wt. % based on polymer weight, to form a liquid phase and a solid phase; (b) separating the solid phase from the liquid phase, and (c) isolating the polymer from the liquid phase.
Claim 3
Dependent Claim
29 words
The method of claim 1 wherein the amount of boric acid is in the range of about 3 to 20 wt. % based on the weight of the polymer.
Claim 4
Dependent Claim
17 words
The method of claim 1 wherein the polymer comprises a macromonomer of at least 3,000 molecular weight.
Claim 5
Dependent Claim
19 words
The method of claim 1 wherein the polymer comprises a vinyl aromatic macromonomer of at least 3,000 molecular weight.
Claim 6
Dependent Claim
12 words
The method of claim 1 wherein the lithium initiator is alkyl lithium.
Claim 7
Dependent Claim
41 words
The method of claim 1 wherein the polymer comprises a macromonomer of at least 3,000 molecular weight, the lithium initiator is alkyl lithium, and the amount of the boric acid is at least 3% based on the weight of the polymer.
Claim 8
Dependent Claim
13 words
The method of claim 6 wherein the polymer comprises a vinyl aromatic macromonomer.
Claim 9
Dependent Claim
12 words
The method of claim 5 wherein the alkyl lithium is s-butyl lithium.
Claim 10
Dependent Claim
12 words
The method of claim 6 wherein the alkyl lithium is s-butyl lithium.
Claim 11
Dependent Claim
12 words
The method of claim 1 wherein the diluent comprises a reactive monomer.
Claim 12
Dependent Claim
12 words
The method of claim 1 wherein the diluent comprises an inert solvent.
Claim 13
Dependent Claim
30 words
The method of claim 1 wherein the boric acid is contained in a filter bed and the polymer solution is contacted with the boric acid by passage through the bed.
Claim 14
Dependent Claim
15 words
The method of claim 12 wherein the filter bed is contained in a packed column.
Claim 15
Dependent Claim
27 words
The method of claim 12 wherein the filter bed comprises a plurality of plates supporting the boric acid, and the polymer solution is pressure-filtered through the plates.
Claim 16
Dependent Claim
99 words
The method of claim 1 wherein the polymer is selected from: (a) polystyrene terminated with acryloyl or methacryloyl chloride; (b) polystyrene capped with ethylene oxide or ethylene sulfide and terminated with acryloyl or methacryloyl chloride; (c) polystyrene capped with ethylene oxide or ethylene sulfide and terminated with chloromethyl styrene; (d) polystyrene capped with ethylene oxide or ethylene sulfide and terminated with epichlorohydrin; (e) polystyrene terminated with allyl chloride; (f) polybutadiene capped with ethylene oxide or ethylene sulfide and terminated with acryloyl or methacryloyl chloride; and (g) any of polymers (a) to (e) with poly alpha-methylstyrene in place of polystyrene.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-05-05 | 1989-11-04 | 1990-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-05 | 1993-11-04 | 1994-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-05 | 1997-11-04 | 1998-05-06 | $7700.00 | Window Closed / Lapsed |