Patent US4568866A successfully refreshed from Google Patents.
US4057531A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fire retardant polystyrene
Assignee: Albemarle Corp
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Filing: 1977-01-31
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Granted: 1977-11-08
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Expires: 1997-01-31
Abstract
Abstract Polystyrene and related polymers are rendered flame retardant by 2,3,5,6-tetrabromo-p-xylene-α,α'-diol. Tests of polystyrene containing the diol show a high degree of stability toward ultraviolet radiation.
Inventors
- 👤 Michael Dubeck
- 👤 David R. Brackenridge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:04
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/04; C08K5/05; C08K5/053; Y; Y10; Y10S; Y10S521/00; Y10S521/907
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
41 words
A flame retardant polystyrene composition comprising (i) a solid polymer of ##STR5## wherein Ar is a benzene or toluene nucleus, and R is --H or --CH 3 ; and (ii) a flame retardant amount of a compound having the formula ##STR6##
Claim 2
Dependent Claim
41 words
A flame retardant polystyrene composition comprising (i) a solid polymer of ##STR5## wherein Ar is a benzene or toluene nucleus, and R is --H or --CH 3 ; and (ii) a flame retardant amount of a compound having the formula ##STR6##
Claim 3
Dependent Claim
10 words
A composition of claim 1 wherein said polymer is polystyrene.
Claim 4
Dependent Claim
10 words
The composition of claim 2 wherein said compound is 2,3,5,6-tetrabromo-p-xylene-α,α'-diol.
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) | 1980-11-07 | 1981-05-09 | 1981-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-07 | 1985-05-09 | 1985-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-07 | 1989-05-09 | 1989-11-08 | $7700.00 | Window Closed / Lapsed |