Patent US2532738A successfully refreshed from Google Patents.
Patent US3231635A successfully refreshed from Google Patents.
US3231635A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of block copolymers
Assignee: Shell USA Inc
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Filing: 1963-10-07
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Granted: 1966-01-25
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Expires: 1983-10-07
Abstract
No abstract record available.
Inventors
- 👤 Holden Geoffrey
- 👤 Milkovich Ralph
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:34
CPC Classifications
C; C08; C08F; C08F297/00; C08F297/02; C08F297/04
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
173 words
A BLOCK COPOLYMERIZATION PROCESS COMPRISING THE STEPS: (A) POLYMERIZING A MONO ALKENYL-SUBSTITUTED AROMATIC HYDROCARBON IN THE PRESENCE OF A CATALYTIC PROPORTION BETWEEN ABOUT 100 AND 2000 PARTS BY WEIGHT PER MILLION PARTS BY WEIGHT OF TOTAL MONOMERS OF A C4-8 ALKYL LITHIUM CATALYST WHEREIN THE CARBON ATOM DIRECTLY ATACHED TO LITHIUM BEARS AT LEAST TWO ALKYL SUBSTITUENTS, WHEREBY A POLYMER BLOCK A-LI IS FORMED, WHEREIN A IS A HOMOPOLYMERIZED AROMATIC HYDROCARBON; (B) INJECTING A CONJUGATED DIENE INTO THE POLYMERIZATION ZONE AND CONTINUING POLYMERIZATION WHEREBY AN INTERMEDIATE BLOCK POLYMER A-B-LI IS FORMED, WHEREIN B IS A HOMOPOLYMERIZED DIENE BLOCK; (C) INJECTING A MONO ALKENYL AROMATIC HYDROCARBON INTO THE POLYMERIZATION ZONE AND CONTINUINING POLYMERIZATION, WHEREBY BLOCK POLYMER A-B-A-LI IS FORMED (D) ADDING A CHAIN TERMINATOR AND (E) RECOVERING THE BLOCK COPOLYMER HAVING THE STRUCTURE A-B-A WHEREIN EACH A HAS AN AVERAGE MOLECULAR WEIGHT BETWEEN ABOUT 10,000 AND 45,000 AND B HAS AN AVERAGE MOLECULAR WEIGHT BETWEEN ABOUT 35,000 AND 150,000, TOTAL WEIGHT OF THE A BLOCKS BEING LESS THAN ABOUT 38% OF THE TOTAL COPOLYMER.
Claim 2
Dependent Claim
173 words
A BLOCK COPOLYMERIZATION PROCESS COMPRISING THE STEPS: (A) POLYMERIZING A MONO ALKENYL-SUBSTITUTED AROMATIC HYDROCARBON IN THE PRESENCE OF A CATALYTIC PROPORTION BETWEEN ABOUT 100 AND 2000 PARTS BY WEIGHT PER MILLION PARTS BY WEIGHT OF TOTAL MONOMERS OF A C4-8 ALKYL LITHIUM CATALYST WHEREIN THE CARBON ATOM DIRECTLY ATACHED TO LITHIUM BEARS AT LEAST TWO ALKYL SUBSTITUENTS, WHEREBY A POLYMER BLOCK A-LI IS FORMED, WHEREIN A IS A HOMOPOLYMERIZED AROMATIC HYDROCARBON; (B) INJECTING A CONJUGATED DIENE INTO THE POLYMERIZATION ZONE AND CONTINUING POLYMERIZATION WHEREBY AN INTERMEDIATE BLOCK POLYMER A-B-LI IS FORMED, WHEREIN B IS A HOMOPOLYMERIZED DIENE BLOCK; (C) INJECTING A MONO ALKENYL AROMATIC HYDROCARBON INTO THE POLYMERIZATION ZONE AND CONTINUINING POLYMERIZATION, WHEREBY BLOCK POLYMER A-B-A-LI IS FORMED (D) ADDING A CHAIN TERMINATOR AND (E) RECOVERING THE BLOCK COPOLYMER HAVING THE STRUCTURE A-B-A WHEREIN EACH A HAS AN AVERAGE MOLECULAR WEIGHT BETWEEN ABOUT 10,000 AND 45,000 AND B HAS AN AVERAGE MOLECULAR WEIGHT BETWEEN ABOUT 35,000 AND 150,000, TOTAL WEIGHT OF THE A BLOCKS BEING LESS THAN ABOUT 38% OF THE TOTAL COPOLYMER.
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) | 1969-01-24 | 1969-07-26 | 1970-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-01-24 | 1973-07-26 | 1974-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-01-24 | 1977-07-26 | 1978-01-25 | $7700.00 | Window Closed / Lapsed |