US4054538A
Expired / Lapsed
US
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π Allyl chromium complex catalyst and process for preparing same
Assignee: Union Carbide Corp
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Filing: 1973-08-03
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Granted: 1977-10-18
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Expires: 1993-08-03
Abstract
Abstract Ethylene polymerization catalyst which is pi allyl chromium compound in the chromium [II] valence state and supported on silica or silica-alumina, and a process for making such catalyst.
Inventors
- 👤 Robert N. Johnson
- 👤 Frederick J. Karol
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:56
CPC Classifications
B; B01; B01J; B01J31/00; B01J31/16; B01J31/1616; B01J31/22; B01J31/2282; B01J31/2291; C; C08; C08F; C08F10/00; C08F10/02; B01J21/00; B01J21/06; B01J21/08; B01J2231/00; B01J2231/10; B01J2231/12; B01J2231/20; B01J2531/00; B01J2531/60; B01J2531/62; C07; C07C; C07C2531/00; C07C2531/16; C07C2531/22
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
62 words
A catalyst for the polymerization of ethylene which consists essentially of a π allyl chromium [III] complex wherein the ligands are only allyl ligands and at least a portion of the chromium is reduced to the chromium [II] valence state, said complex being supported on an inorganic oxide of high surface area and selected from the group consisting of silica and silica-alumina.
Claim 2
Dependent Claim
62 words
A catalyst for the polymerization of ethylene which consists essentially of a π allyl chromium [III] complex wherein the ligands are only allyl ligands and at least a portion of the chromium is reduced to the chromium [II] valence state, said complex being supported on an inorganic oxide of high surface area and selected from the group consisting of silica and silica-alumina.
Claim 3
Dependent Claim
25 words
A catalyst as claimed in claim 1 in which substantially all of the π allyl chromium [III] complex is in the chromium [II] valence state.
Claim 4
Dependent Claim
14 words
A catalyst as in claim 2 in which the inorganic oxide support is silica.
Claim 5
Dependent Claim
70 words
A process for preparing an allyl chromium catalyst for the polymerization of ethylene which consists essentially of reducing at least a portion of the chromium in a π allyl chromium [III] complex wherein the ligands are only allyl groups to the chromium [II] valence state and depositing the reduced allyl chromium complex on an inorganic oxide of high surface area and selected from the group consisting of silica and silica-alumina.
Claim 6
Dependent Claim
70 words
A process for preparing an allyl chromium catalyst for the polymerization of ethylene which consists essentially of reducing at least a portion of the chromium in a π allyl chromium [III] complex wherein the ligands are only allyl groups to the chromium [II] valence state and depositing the reduced allyl chromium complex on an inorganic oxide of high surface area and selected from the group consisting of silica and silica-alumina.
Claim 7
Dependent Claim
13 words
A process as in claim 4 in which the inorganic oxide is silica.
Claim 8
Dependent Claim
29 words
A process as claimed in claim 4 in which the π allyl chromium [III] complex is reduced to the chromium [II] valence state at a temperature above -17° C.
Claim 9
Dependent Claim
26 words
A process as claimed in claim 6 in which substantially all of the π allyl chromium [III] complex is reduced to the chromium [II] valence state.
Claim 10
Dependent Claim
41 words
A process as claimed in claim 4 in which the allyl chromium complex is subjected to a temperature of between about -17° to about 80° C. for about 1 to about 30 minutes prior to deposition onto the inorganic oxide support.
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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) | 1980-10-17 | 1981-04-18 | 1981-10-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-17 | 1985-04-18 | 1985-10-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-17 | 1989-04-18 | 1989-10-18 | $7700.00 | Window Closed / Lapsed |