US5334677A
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Process for producing syndiotactic polyolefins
Assignee: Fina Technology Inc
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Filing: 1991-11-15
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Granted: 1994-08-02
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Expires: 2011-11-15
Abstract
Abstract The invention provides a metallocene catalyst for use in preparing syndiotactic polyolefins. The catalyst comprises a bridged metallocene in which one of the cyclopentadienyl rings is substituted in a substantially different manner from the other ring. It was discovered that this type of catalyst is highly syndiospecific, and it also produces a polymer with a novel microstructure. The invention further includes the use of one or more of the catalysts in a polymerization process. The catalyst is generally described by the formula R"(CpR.sub.n)(CpR'.sub.m)MeQ.sub.k wherein each Cp is a cyclopentadienyl or substituted cyclopentadienyl ring; each R n and R' m is the same or different and is a hydrocarbyl radicals having 1-20 carbon atoms; R" is a structural bridge between the two Cp rings imparting stereorigidity to the catalyst; Me is a group 4b, 5b, or 6b metal from the Periodic Table of Elements; each Q is a hydrocarbyl radical having 1-20 carbon atoms or is a halogen; 0≦k≦3; 0≦n≦4; 1≦m≦4; and wherein R' m is selected such that (CpR' m ) is a sterically different ring than (CpR n ).
Inventors
- 👤 Abbas Razavi
- 👤 John A. Ewen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:23
CPC Classifications
C; C08; C08F; C08F4/00; C08F4/42; C08F4/72; C08F4/74; C08F110/00; C08F110/04; C08F110/06; C07; C07F; C07F17/00; C08F10/00; C08F4/44; C08F4/60; C08F4/62; C08F4/622; C08F4/64; C08F4/639; C08F4/63912; C08F4/6392; C08F4/63922; C08F4/63927; Y; Y10; Y10S; Y10S526/00; Y10S526/943
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
164 words
A process for polymerizing an olefin monomer, said process comprising: a) selecting a metallocene catalyst described by the formula R"(Cp[R.sub.n ])(CpR'.sub.m)MeQ.sub.k wherein Cp is a cyclopentadienyl and CpR' m is a substituted cyclopentadienyl ring; R" is a structural bridge between the Cp ring and the CpR' m ring imparting stereorigidity to the catalyst; Me is a group 4b, 5b, or 6b metal from the Periodic Table of Elements; each Q is hydrocarbyl radical having 1-20 carbon atoms or is a halogen; 0≦k≦3; and wherein (CpR' m ) is a sterically different ring than (Cp[R n ]); b) combining an aluminum cocatalyst selected from the group consisting of alumoxanes and mixtures of alumoxanes and alkylaluminums with the catalyst of a); c) introducing the catalyst into a polymerization reaction zone containing an olefin monomer and maintaining the reaction zone under polymerization reaction conditions; and d) forming a syndiotactic polyolefin; wherein (CpR' m ) is a fluorenyl radical and (Cp[R n ]) is an unsubstituted cyclopentadienyl radical.
Claim 2
Dependent Claim
164 words
A process for polymerizing an olefin monomer, said process comprising: a) selecting a metallocene catalyst described by the formula R"(Cp[R.sub.n ])(CpR'.sub.m)MeQ.sub.k wherein Cp is a cyclopentadienyl and CpR' m is a substituted cyclopentadienyl ring; R" is a structural bridge between the Cp ring and the CpR' m ring imparting stereorigidity to the catalyst; Me is a group 4b, 5b, or 6b metal from the Periodic Table of Elements; each Q is hydrocarbyl radical having 1-20 carbon atoms or is a halogen; 0≦k≦3; and wherein (CpR' m ) is a sterically different ring than (Cp[R n ]); b) combining an aluminum cocatalyst selected from the group consisting of alumoxanes and mixtures of alumoxanes and alkylaluminums with the catalyst of a); c) introducing the catalyst into a polymerization reaction zone containing an olefin monomer and maintaining the reaction zone under polymerization reaction conditions; and d) forming a syndiotactic polyolefin; wherein (CpR' m ) is a fluorenyl radical and (Cp[R n ]) is an unsubstituted cyclopentadienyl radical.
Claim 3
Dependent Claim
12 words
The process of claim 1 wherein Me is titanium, zirconium or hafnium.
Claim 4
Dependent Claim
29 words
The process of claim 1 wherein R" is a divalent alkyl radical having 1-4 carbon atoms or a divalent hydrocarbyl radical containing silicon, germanium, phosphorus, nitrogen, boron or aluminum.
Claim 5
Dependent Claim
18 words
The process of claim 1 wherein R" is an ethylene, isopropylidene, cyclopropylidene, dimethyl silylidene or a methylene radical.
Claim 6
Dependent Claim
17 words
The process of claim 1 wherein R" (Cp[R n ]) (CpR' m ) is an isopropylidene(cyclopentadienyl-1-fluorenyl) radical.
Claim 7
Dependent Claim
20 words
The process of claim 1 comprising using b) as an isolated complex of the metallocene catalyst and the aluminum cocatalyst.
Claim 8
Dependent Claim
34 words
The process of claim 1 further comprising prepolymerizing the catalyst prior to introducing it into the reaction zone, said step of prepolymerizing including contacting the catalyst with the olefin monomer and the aluminum cocatalyst.
Claim 9
Dependent Claim
184 words
A process for polymerizing an olefin monomer, said process comprising: a) utilizing at least two different metallocene catalysts described by the formula R"(Cp[R.sub.n ])(CpR'.sub.m)MeQ.sub.k wherein Cp is a cyclopentadienyl and CpR' m is a substituted cyclopentadienyl ring; R" is a structural bridge between the Cp ring and the CpR' m ring imparting stereorigidity to the catalyst; Me is a group 4b, 5b, or 6b metal from the Periodic Table of Elements; each Q is a hydrocarbyl radical having 1-20 carbon atoms or is a halogen; 0≦k≦3; wherein (CpR' m ) is a sterically different ring than (Cp[R n ]); b) combining an aluminum cocatalyst selected from the group consisting of alumoxanes and mixtures of alumoxanes and alkylaluminums with the catalyst of a); c) introducing the catalyst into a polymerization reaction zone containing an olefin monomer and maintaining the reaction zone under polymerization reaction conditions; and d) forming a syndiotactic polyolefin having a broad molecular weight distribution; wherein R' m is selected such (CpR' m ) is a fluorenyl radical and R n is selected such that (Cp[R n ]) is an unsubstituted cyclopentadienyl radical.
Claim 10
Dependent Claim
184 words
A process for polymerizing an olefin monomer, said process comprising: a) utilizing at least two different metallocene catalysts described by the formula R"(Cp[R.sub.n ])(CpR'.sub.m)MeQ.sub.k wherein Cp is a cyclopentadienyl and CpR' m is a substituted cyclopentadienyl ring; R" is a structural bridge between the Cp ring and the CpR' m ring imparting stereorigidity to the catalyst; Me is a group 4b, 5b, or 6b metal from the Periodic Table of Elements; each Q is a hydrocarbyl radical having 1-20 carbon atoms or is a halogen; 0≦k≦3; wherein (CpR' m ) is a sterically different ring than (Cp[R n ]); b) combining an aluminum cocatalyst selected from the group consisting of alumoxanes and mixtures of alumoxanes and alkylaluminums with the catalyst of a); c) introducing the catalyst into a polymerization reaction zone containing an olefin monomer and maintaining the reaction zone under polymerization reaction conditions; and d) forming a syndiotactic polyolefin having a broad molecular weight distribution; wherein R' m is selected such (CpR' m ) is a fluorenyl radical and R n is selected such that (Cp[R n ]) is an unsubstituted cyclopentadienyl radical.
Claim 11
Dependent Claim
29 words
The process of claim 8 wherein R" is a divalent alkyl radical having 1-4 carbon atoms or a divalent hydrocarbyl radical containing silicon, germanium, phosphorus, nitrogen, boron or aluminum.
Claim 12
Dependent Claim
18 words
The process of claim 8 wherein R" is an ethylene, isopropylidene, cyclopropylidene, dimethyl silylidene or a methylene radical.
Claim 13
Dependent Claim
17 words
The process of claim 8 wherein R" (Cp[R n ]) (CpR' m ) forms an isopropylidene(cyclopentadienyl-1-fluorenyl) radical.
Claim 14
Dependent Claim
20 words
The process of claim 8 comprising using b) as an isolated complex of the metallocene catalyst and the aluminum cocatalyst.
Claim 15
Dependent Claim
34 words
The process of claim 8 further comprising prepolymerizing the catalyst prior to introducing it into the reaction zone, said step of prepolymerizing including contacting the catalyst with the olefin monomer and an aluminum cocatalyst.
References Cited (Backward Citations)
US3305538A
Cited
US4522982A
Cited
US4935474A
Cited
US4769510A
Cited
US4752597A
Cited
US4849487A
Cited
US4874734A
Cited
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