US3558575A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of copolymers free of block polystyrene
Assignee: Bridgestone Firestone Inc
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Filing: 1970-01-05
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Granted: 1971-01-26
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Expires: 1990-01-05
Abstract
Abstract BUTADIENE AND STYRENE ARE COPOLYMERIZED TO PRODUCE A RUBBER USING HYDROCARBON LITHIUM CATALYST WITH A LOW PERCENTAGE CONTENT OF BLOCK STYRENE BY CARRYING OUT THE REACTION AT AN ELEVATED TEMPERATURE AND ADDING THE MONOMERS TO THE REACTION MIXTURE AT SUCH A RATE THAT THERE IS A SUBSTANTIAL RISE IN THE TEMPERATURE ADIABATICALLY DUE TO THE HEAT OF THE REACTION.
Inventors
- 👤 Norman F Keckler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 03:39
CPC Classifications
C; C08; C08F; C08F236/00; C08F236/02; C08F236/04; C08F236/10
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-25 | 1974-07-27 | 1975-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-25 | 1978-07-27 | 1979-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-25 | 1982-07-27 | 1983-01-26 | $7700.00 | Window Closed / Lapsed |