EP0416784A2
Expired / Lapsed
EP
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Chromium-containing complex polymerisation catalyst
Assignee: BP Chemicals Ltd
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Filing: 1990-08-23
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Granted: —
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Expires: 2010-08-23
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 characterised in that the mononuclear chromium complex is representable by the general formula: wherein: - the cyclopentadienyl ligand is substituted with 4 or 5 hydrocarbon groups containing 1 to 3 carbon atoms, - x is an integer from 1 to 4, and - L is either a four-or five-substituted cyclopentadienyl ligand, or (CO)₃R in which R is H, methyl or ethyl. The catalyst is used for polymerizing olefins, particularly ethylene optionally with C₃-C₈ alpha-olefins. It produces polyolefins having a relatively high molecular weight and a broad molecular weight distribution.
Inventors
- 👤 Gordon Michael Dawkins
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 08:50
CPC Classifications
C; C08; C08F; C08F4/00; C08F10/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
138 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: wherein - four of the groups R₁ to R₅ 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, x is an integer from 1 to 4 depending on the available co-ordination sites on the chromium atom and - 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
138 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: wherein - four of the groups R₁ to R₅ 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, x is an integer from 1 to 4 depending on the available co-ordination sites on the chromium atom and - 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
43 words
An olefin polymerization catalyst as claimed in any one of claims 1 to 3 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 any one of claims 1 to 4 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
127 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: wherein - four of the groups R₁ to R₅ 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, - x is an integer from 1 to 4 depending on the available co-ordination sites on the chromium atom and - 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
40 words
A process for the production of polyolefins comprising contacting the olefin monomer or monomers with an olefin polymerization catalyst as claimed in any one of claims 1 to 5 at a temperature and pressure sufficient to initiate the polymerization reaction.
Claim 10
Dependent Claim
32 words
A process as claimed in claim 8 in which the polyolefin is a homopolymer of ethylene or a copolymer of ethylene with minor amounts of at least one C₃ to C₈ alpha-olefin.
Claim 11
Dependent Claim
17 words
A polyolefin obtainable by a process as claimed in any one of claim 8 or claim 9.
References Cited (Backward Citations)
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