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US4200703A
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US
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Process for the manufacture of heat-stable, nuclear-brominated polystyrenes
Assignee: Vibrantz Corp
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Filing: 1979-01-02
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Granted: 1980-04-29
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Expires: 1999-01-02
Abstract
Abstract In a process for the manufacture of a heat-stable, nuclear-brominated polystyrene by brominating, at -20 DEG C. to +40 DEG C., a polystyrene dissolved in a chlorinated hydrocarbon in the presence of a Lewis acid catalyst, an improvement is provided wherein the catalyst further comprises 0.02 to 2 moles, per mole of Lewis acid, of a nucleophilic substance which acts as a Lewis base for the Lewis acid.
Inventors
- 👤 Klaus Diebel
- 👤 Horst-Dieter Wulf
- 👤 Raban Grundmann
- 👤 Gunther Maahs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:34
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/18; C08F8/20; C08F8/22
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
77 words
A process for the manufacture of a heatstable, nuclear-brominated polystyrene comprising brominating, at -20° C. to +40° C., a polystyrene dissolved in a chlorinated hydrocarbon in the presence of a Lewis acid catalyst, and 0.02 to 2 moles, per mole of Lewis acid, of a nucleophilic substance which acts as a Lewis base for the Lewis acid, the amount of Lewis base being selected within this range such that the polystyrene is essentially not crosslinked during bromination.
Claim 2
Dependent Claim
77 words
A process for the manufacture of a heatstable, nuclear-brominated polystyrene comprising brominating, at -20° C. to +40° C., a polystyrene dissolved in a chlorinated hydrocarbon in the presence of a Lewis acid catalyst, and 0.02 to 2 moles, per mole of Lewis acid, of a nucleophilic substance which acts as a Lewis base for the Lewis acid, the amount of Lewis base being selected within this range such that the polystyrene is essentially not crosslinked during bromination.
Claim 3
Dependent Claim
21 words
The process of claim 1, wherein the nucleophilic substance is added to the chlorinated hydrocarbon before the reaction is carried out.
Claim 4
Dependent Claim
17 words
The process of claim 1, wherein the polystyrene has a molecular weight of greater than 8,000 (weight-average).
Claim 5
Dependent Claim
17 words
The process of claim 3, wherein the polystyrene has a molecular weight of 50,000 to 500,000 (weight-average).
Claim 6
Dependent Claim
10 words
The process of claim 1, wherein the polystyrene is homopolystyrene.
Claim 7
Dependent Claim
28 words
The process of claim 1, wherein the Lewis acid is aluminum-III chloride and the nucleophilic substance is 0.4 to 0.8 mole of water per mole of aluminum-III chloride.
Claim 8
Dependent Claim
28 words
The process of claim 1, wherein the Lewis acid is iron-III chloride and the nucleophilic substance is 0.05 to 0.2 mole of water per mole of iron-III chloride.
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) | 1983-04-29 | 1983-10-29 | 1984-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-29 | 1987-10-29 | 1988-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-29 | 1991-10-29 | 1992-04-29 | $7700.00 | Window Closed / Lapsed |