US3725506A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of copolymers of styrene and {60 -methylstyrene
Assignee: BASF SE
•
Filing: 1971-11-16
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Granted: 1973-04-03
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Expires: 1991-11-16
Abstract
Abstract Continuous process for the manufacture of copolymers of styrene and Alpha -methylstyrene having a substantially statistical distribution of the monomers by anionic polymerization at low temperatures with thorough mixing of the reactants. The process is characterized in that at least part of the heat of reaction is removed by evaporative cooling and that the monomers are fed to the polymerization zone at different points.
Inventors
- 👤 H Bolte
- 👤 P Wittmer
- 👤 E Heil
- 👤 H Willersinn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:05
CPC Classifications
C; C08; C08F; C08F212/00; C08F212/02; C08F212/04; C08F212/06; C08F212/08; Y; Y10; Y10S; Y10S526/00; Y10S526/922
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
19 words
A process as claimed in claim 1, wherein polymerization is carried out at a temperature between 0* and -30*C.
Claim 2
Dependent Claim
20 words
A process as claimed in claim 2 wherein the ratio of styrene to Alpha -methylstyrene is from 70:30 to 40:60.
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) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |