US4689368A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polymerization of conjugated dienes
Assignee: Enoxy Chemical Ltd
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Filing: 1986-08-04
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Granted: 1987-08-25
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Expires: 2006-08-04
Abstract
Abstract The invention relates to a catalyst system comprising (a) a compound of a rare earth element and, as cocatalyst, a second component (b) comprising an organomagnesium compound. In the polymerization of a conjugated diene this catalyst gives a polymer having a very high content of trans 1,4 isomer. A third component (c) which is a Lewis acid alters the reaction to give a polymer having a very high content of cis 1,4 isomer. If desired reaction can be initiated using components (a) and (b) alone and component (c) then added at the desired conversion to produce a block polymer having a block of high trans content followed by a block of high cis content.
Inventors
- 👤 Derek K. Jenkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:45
CPC Classifications
C; C08; C08F; C08F36/00; C08F36/02; C08F36/04
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
113 words
A process for the preparation of a block copolymer of one or more conjugated dienes comprising a first block having a high content of trans isomer and a second block having a high content of cis isomer by a sequential polymerisation in which: the first block is prepared in a first stage using a catalyst comprising (a) a salt of a rare earth element or a complex of a rare earth element and (b) a dialkyl magnesium compound; and the second block is prepared in a second stage using a Lewis Acid as an additional catalyst component, (c), in a mole ratio of (c):(b) of a least 0.5:1, added partway through the polymerisation.
Claim 2
Dependent Claim
113 words
A process for the preparation of a block copolymer of one or more conjugated dienes comprising a first block having a high content of trans isomer and a second block having a high content of cis isomer by a sequential polymerisation in which: the first block is prepared in a first stage using a catalyst comprising (a) a salt of a rare earth element or a complex of a rare earth element and (b) a dialkyl magnesium compound; and the second block is prepared in a second stage using a Lewis Acid as an additional catalyst component, (c), in a mole ratio of (c):(b) of a least 0.5:1, added partway through the polymerisation.
Claim 3
Dependent Claim
26 words
A process according to claim 1 wherein the block copolymer comprises a first block of high trans polybutadiene and a second block of high cis polybutadiene.
Claim 4
Dependent Claim
26 words
A process according to claim 1 wherein the block copolymer comprises a first block of high trans polybutadiene and a second block of high cis polyisoprene.
Claim 5
Dependent Claim
21 words
A process according to claim 1 wherein both the first and second blocks are prepared from two or more conjugated dienes.
Claim 6
Dependent Claim
24 words
A process according to claim 1 wherein component (a) is a rare earth carboxylate, a rare earth alkoxide or a rare earth diketone complex.
Claim 7
Dependent Claim
24 words
A process according to claim 5 wherein the rare earth element of component (a) is neodymium or a mixture of neodymium, lanthanum and praseodymium.
Claim 8
Dependent Claim
12 words
A process according to claim 1 wherein component (b) is dibutyl magnesium.
Claim 9
Dependent Claim
19 words
A process according to claim 1 wherein the Lewis Acid used as component (c) is an aluminium alkyl halide.
Claim 10
Dependent Claim
17 words
A process according to claim 8 wherein component (c) is ethyl aluminium sesquichloride or ethyl aluminium sesquibromide.
Claim 11
Dependent Claim
17 words
A process according to claim 1 wherein the mole 5 ratio of (c):(b) is 0.5:1 to 2:1.
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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) | 1990-08-24 | 1991-02-23 | 1991-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-08-24 | 1995-02-23 | 1995-08-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-08-24 | 1999-02-23 | 1999-08-25 | $7700.00 | Window Closed / Lapsed |