Patent US2390660A successfully refreshed from Google Patents.
Patent US4774301A successfully refreshed from Google Patents.
US4774301A
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Zirconium containing catalysts and method of use
Assignee: Dow Chemical Co
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Filing: 1987-06-08
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Granted: 1988-09-27
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Expires: 2007-06-08
Abstract
Abstract Polymers of vinyl aromatic monomers having a high degree of syndiotacticity are prepared by contacting with a catalyst comprising a zirconium (IV) complex and polymethylaluminoxane under polymerization conditions.
Inventors
- 👤 Richard E. Campbell, Jr.
- 👤 Gregory F. Schmidt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:06
CPC Classifications
C; C08; C08F; C08F10/00; C08F12/00; C08F12/02; C08F12/04
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
110 words
A process for the preparation of polymers of vinyl aromatic monomers having a high degree of syndiotacticity comprising contacting one or more vinyl aromatic monomers under polymerization conditions with a catalyst comprising the reaction product of polymethylaluminoxane and a zirconium (IV) complex corresponding to the formula: ZrXR 3 , wherein X is halide or R, and R is independently each occurrence selected from the ligand group consisting of alkoxides and aryloxides corresponding to the formula: OR'; amides corresponding to the formula: NR' 2 ; phosphides corresponding to the formula: PR' 2 ; and β-diketonates corresponding to the formula: R'--C(O)--CH--C(O)--R', and R' is alkyl or aryl of up to 12 carbons.
Claim 2
Dependent Claim
110 words
A process for the preparation of polymers of vinyl aromatic monomers having a high degree of syndiotacticity comprising contacting one or more vinyl aromatic monomers under polymerization conditions with a catalyst comprising the reaction product of polymethylaluminoxane and a zirconium (IV) complex corresponding to the formula: ZrXR 3 , wherein X is halide or R, and R is independently each occurrence selected from the ligand group consisting of alkoxides and aryloxides corresponding to the formula: OR'; amides corresponding to the formula: NR' 2 ; phosphides corresponding to the formula: PR' 2 ; and β-diketonates corresponding to the formula: R'--C(O)--CH--C(O)--R', and R' is alkyl or aryl of up to 12 carbons.
Claim 3
Dependent Claim
25 words
A process according to claim 1, wherein the monomer is contacted with the catalyst at a temperature from about 25° C. to about 100° C.
Claim 4
Dependent Claim
13 words
A process according to claim 1, wherein an inert diluent is additionally present.
Claim 5
Dependent Claim
20 words
A process according to claim 1, wherein the polymer has a molecular structure containing greater than about 65 percent syndiotactic.
Claim 6
Dependent Claim
33 words
A process according to claim 1, wherein the zirconium (IV) complex is selected from the group consisting of zirconium tetraalkoxides having from 2 to 4 carbons in the alkyl group, and zirconium tetraphenoxide.
Claim 7
Dependent Claim
14 words
A process according to claim 1, wherein the zirconium (IV) complex is zirconium tetraisopropoxide.
Claim 8
Dependent Claim
21 words
A process according to claim 1, wherein the molar ratio of polymethylaluminoxane to zirconium is from about 10:1 to about 50,000:1.
Claim 9
Dependent Claim
21 words
A process according to claim 1, wherein the molar ratio of polymethylalmunioxane to zirconium is from about 100:1 to about 10,000:1
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) | 1991-09-27 | 1992-03-28 | 1992-09-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-27 | 1996-03-28 | 1996-09-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-27 | 2000-03-28 | 2000-09-27 | $7700.00 | Window Closed / Lapsed |