Patent US3265680A successfully refreshed from Google Patents.
US3265680A
Expired / Lapsed
US
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Polymerization of isoprene
Assignee: Bridgestone Firestone Inc
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Filing: 1957-09-11
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Granted: 1966-08-09
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Expires: 1977-09-11
Abstract
No abstract record available.
Inventors
- 👤 Lawrence E Forman
- 👤 Richard S Stearns
- 👤 Richard W Kibler
- 👤 Francis A Bozzacco
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:34
CPC Classifications
C; C08; C08F; C08F136/00; C08F136/02; C08F136/04; C08F136/06
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
120 words
PROCESS OF POLYMERIZING ISOPRENE TO PRODUCE A RUBBERY POLYISOPRENE WHICH, BY INFRA-RED ANALYSIS, EXHIBITS AT LEAST ABOUT 75% CIS-1,4-STRUCTURE, NOT MORE THAN ABOUT 7 TO 10% TRANS-1,4-STRUCTURE, NOT MORE THAN ABOUT 10% 3,4-STRUUCTUURE AND ESSENTIALLY NO 1,2-STRUCTURE WHICH PROCESS COMPRISES CONTACTING ISOPRENE OF A PURITY IN EXCESS OF 90 MOL PERCENT WITH A HYDROCARBON LITHIUM CONTAINING A SINGLE ATOM OF LITHIUM PER MOLECULE, THE HYDROCARBON GROUP IN SAID HYDROCARBON LITHIUM CONTAINING FROM 1 TO 40 CARBON ATOMS, THE AMOUNT OF HYDROCARBON LITHIUM BEING SUFFICIENT TO PROVIDE NOT MORE THAN 0.1 GRAM OF CARBON-LINKED LITHIUM EXPRESSED AS LITHIUM METAL FOR EACH 100 GRAMS OF ISOPRENE AND THE POLYMERIZATION SYSTEM BEING ESSENTIALLY FREE FROM FOREIGN MATERIAL OTHER THAN HYDROCARBONS OF NON-ACIDIC CHARACTER.
Claim 2
Dependent Claim
120 words
PROCESS OF POLYMERIZING ISOPRENE TO PRODUCE A RUBBERY POLYISOPRENE WHICH, BY INFRA-RED ANALYSIS, EXHIBITS AT LEAST ABOUT 75% CIS-1,4-STRUCTURE, NOT MORE THAN ABOUT 7 TO 10% TRANS-1,4-STRUCTURE, NOT MORE THAN ABOUT 10% 3,4-STRUUCTUURE AND ESSENTIALLY NO 1,2-STRUCTURE WHICH PROCESS COMPRISES CONTACTING ISOPRENE OF A PURITY IN EXCESS OF 90 MOL PERCENT WITH A HYDROCARBON LITHIUM CONTAINING A SINGLE ATOM OF LITHIUM PER MOLECULE, THE HYDROCARBON GROUP IN SAID HYDROCARBON LITHIUM CONTAINING FROM 1 TO 40 CARBON ATOMS, THE AMOUNT OF HYDROCARBON LITHIUM BEING SUFFICIENT TO PROVIDE NOT MORE THAN 0.1 GRAM OF CARBON-LINKED LITHIUM EXPRESSED AS LITHIUM METAL FOR EACH 100 GRAMS OF ISOPRENE AND THE POLYMERIZATION SYSTEM BEING ESSENTIALLY FREE FROM FOREIGN MATERIAL OTHER THAN HYDROCARBONS OF NON-ACIDIC CHARACTER.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-08-08 | 1970-02-07 | 1970-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-08-08 | 1974-02-07 | 1974-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-08-08 | 1978-02-07 | 1978-08-09 | $7700.00 | Window Closed / Lapsed |