US5169815A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chromium-containing complex polymerization catalyst
Assignee: BP Chemicals Ltd
•
Filing: 1990-08-29
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Granted: 1992-12-08
•
Expires: 2010-08-29
Abstract
Abstract The present invention relates to an olefin polymerization catalyst obtainable by depositing on a dry inorganic oxide support a monocuclear chromium complex to produce a catalyst precursor and thereafter by thermally activating the said catalyst precursor. The catalyst is characterized in that the mononuclear chromium complex is representable by the general formula: ##STR1## wherein: the cyclopentadienyl ligand is substituted with 4 or 5 hydrocarbon groups containing 1 to 3 carbon atoms, L is either a four or five-substituted cyclopentadienyl ligand, or (CO) 3 R in which R is H, methyl or ethyl. The catalyst is used for polymerizing olefins, particularly ethylene optionally with C 3 -C 8 alpha-olefins. It produces polyolefins having a relatively high molecular weight and a broad molecular weight distribution.
Inventors
- 👤 Gordon M. Dawkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 07:20
CPC Classifications
C; C08; C08F; C08F4/00; C08F10/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
121 words
An olefin polymerization catalyst obtainable by depositing on a dry inorganic oxide support a mononuclear chromium complex to produce a catalyst precursor and thereafter thermally activating the said catalyst precursor, characterised in that the mononuclear chromium complex is representable by the general formula: ##STR4## wherein four of the groups R 1 to R 5 of the substituted cyclopentadienyl ligand are individually selected from the group consisting of methyl, ethyl, isopropyl and n-propyl and the fifth is selected from the group consisting of methyl, ethyl, n-propyl, isopropyl and hydrogen, L is (a) a cyclopentadienyl ligand substituted with four or five groups individually selected from methyl, ethyl, isopropyl and n-propyl or (b) (CO) 3 R in which R is H, methyl or ethyl.
Claim 2
Dependent Claim
121 words
An olefin polymerization catalyst obtainable by depositing on a dry inorganic oxide support a mononuclear chromium complex to produce a catalyst precursor and thereafter thermally activating the said catalyst precursor, characterised in that the mononuclear chromium complex is representable by the general formula: ##STR4## wherein four of the groups R 1 to R 5 of the substituted cyclopentadienyl ligand are individually selected from the group consisting of methyl, ethyl, isopropyl and n-propyl and the fifth is selected from the group consisting of methyl, ethyl, n-propyl, isopropyl and hydrogen, L is (a) a cyclopentadienyl ligand substituted with four or five groups individually selected from methyl, ethyl, isopropyl and n-propyl or (b) (CO) 3 R in which R is H, methyl or ethyl.
Claim 3
Dependent Claim
20 words
An olefin polymerization catalyst as claimed in claim 1 in which the mononuclear chromium complex is bis (pentamethylcyclopentadienyl) chromium (II).
Claim 4
Dependent Claim
23 words
An olefin polymerization catalyst as claimed in claim 1 or claim 2 in which the inorganic oxide comprises a major amount of silica.
Claim 5
Dependent Claim
41 words
An olefin polymerization catalyst as claimed in claim 1 or claim 2 in which the amount of chromium deposited on the inorganic oxide support is from 0.01 to 10% by weight of the total weight of the complex and inorganic oxide.
Claim 6
Dependent Claim
49 words
An olefin polymerization catalyst as claimed in claim 1 or claim 2 in which the dry inorganic support on which the mononuclear chromium complex is deposited is thermally activated by heating at a temperature of at least 100° C. but less than 350° C. in a dry, inert atmosphere.
Claim 7
Dependent Claim
109 words
A catalyst precursor for forming a catalyst as claimed in claim 1 comprising a dry inorganic oxide support on which is deposited a mononuclear chromium complex representable by the general formula; ##STR5## wherein four of the groups R 1 to R 5 of the substituted cyclopentadienyl ligand are individually selected from the group consisting of methyl, ethyl, isopropyl and n-propyl and the fifth is selected from the group consisting of methyl, ethyl, isopropyl, n-propyl and hydrogen, L is (a) a cyclopentadienyl ligand substituted with four or five groups individually selected from methyl, ethyl, isopropyl and n-propyl or (b) (CO) 3 R in which R is H, methyl or ethyl.
Claim 8
Dependent Claim
31 words
A catalyst precursor as claimed in claim 6 in which the chromium content is from 0.01 to 10% by weight based on the total weight of the complex and inorganic oxide.
Claim 9
Dependent Claim
73 words
An olefin polymerization catalyst as claimed in claim 2 wherein the inorganic oxide comprises a major amount of silica, the amount of chromium deposited on the inorganic oxide support is from 0.01 to 10% by weight of the total weight of the complex and inorganic oxide, and the catalyst precursor is thermally activated by heating at a temperature of at least 100° C. but less than 350° C. in a dry inert atmosphere.
Claim 10
Dependent Claim
47 words
A catalyst precursor as claimed in claim 7 in which the inorganic oxide comprises a major amount of silica and the amount of chromium deposited on the inorganic oxide support is from 0.01° to 10° by weight of the total weight of the complex and inorganic oxide.
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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) | 1995-12-08 | 1996-06-08 | 1996-12-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-12-08 | 2000-06-08 | 2000-12-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-12-08 | 2004-06-08 | 2004-12-08 | $7700.00 | Window Closed / Lapsed |