US 6,605,676 B1Granted

Process for obtaining polyolefins with broad bimodal or multimodal molecular weight distributions

AssigneeRepsol Quimica S.A.

InventorsWilfried Michiels Vega, Antonio Munoz-Escalona

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Abstract

The process is characterized by the use of catalyst systems consisting of a single metallocene catalyst activated with mixtures of at least 2 co-catalysts. The co-catalysts are aluminium alkyls, aluminoxanes or boron compounds. Different active centers are produced in the catalyst through the use of these mixed co-catalyst systems, each having different rates of initiation and completion of the polymerization reaction, which give rise to polyolefins with different molecular weights, resulting in products with broad bimodal or multimodal molecular weight distributions and the incorporation of co-monomer can be controlled by appropriate selection of the metallocene and use of combinations of different types of co-catalysts, as well as by varying the reactor pressure, the reaction temperature and the molar ratios between the various components of the catalyst system. A broad bimodal or multimodal molecular weight distribution can be achieved in both the presence and absence of hydrogen during the polymerization reaction. Likewise broad bimodal and multimodal molecular weight distributions can be obtained in polymers by varying the order in which the components of the catalyst system are added. This process may also be used with both homogeneous and heterogenous metallocene catalysts.

Claims24

Dependent claims

A process for obtaining homopolymers or copolymers of ethylene with wide bimodal or multimodal molecular weight distributions, wherein ethylene, alone or with an alpha olefin, is polymerized in the presence of a catalyst system which consists of:

(a) a single supported or unsupported metallocene catalyst being a mono, or dicyclopentdienyl of transition metals in any of groups 4b, 5b, 6b of the Periodic Table of elements represented by the formulae:
(C5R′m)pR″s(C5R′m)MeQ3-p
or
R″s(C5R′m)2 MeQ′
where (C5R′m) is cyclopentadienyl or substituted cyclopentadienyl, each R′ may be the same or different and may be hydrogen, monohydrocarbon radicals selected from the group consisting alkyl, alkenyl, aryl, alkylaryl or arylalkyl containing from 1 to 20 carbon atoms, or two adjacent carbon atoms joined to form a C4-C6 ring, where R″ is an alkylene radical containing from 1 to 4 carbon atoms, a dialkyl germanium, a dialkyl silicon radical or an alkylphosphine or amino radical joining two (C5R′m) rings, Q is a hydrocarbon radical selected from the group consisting of aryl, alkyl, alkenyl, alkylaryl, and arylalkyl containing from 1 to 20 carbon atoms, optionally halogen, and each of said hydrocarbon radicals may be the same or different, Q′ is an alkylidine radical containing from 1 to 20 carbon atoms, Me is a transition metal in groups 4b, 5b or 6b of the Periodic Table of elements, s is 0 or 1, p is 0, 1 or 2;
when p is 0, s is 0;
m is 4 if s is 1 and m is 5 if s is 0;
(b) a co-catalyst formed by a combination of an aluminum compound having Al—O bonds corresponding to the formulae:
(RAlO)n
or
R(R—Al—O)n AlR2
where R is an alkyl or aryl group containing from 1 to 20 carbon atoms, and n is a number from 1 to 20, and at least one Boron compound corresponding to the general formulae:
BX1X2X3
or
(Y) (BX1X2X3X4)
where B is boron, and X1, X2, X3, X4 are the same or different and may be hydride, halide, alkyl containing from 1 to 20 carbon atoms, substituted alkyls containing from 1 to 20 carbon atoms in which one or more hydrogens are substituted by halogens, metal hydrocarbon radicals(organometalloids) in which each substitution contains from 1 to 20 carbon atoms, and the metal is selected from the group consisting of group 4a of the Periodic Table of elements, aryl, and substituted aryls containing from 6 to 20 carbon atoms and Y is a Bronsted acid, optionally in the presence of at least one alkyl aluminum of formula
AlR″′3
where the R″′ groups, which may be the same or different, may be alkyls or aryls containing from 1 to 20 carbon atoms or halogens, and Al is aluminum.

15 more elements

A process for obtaining homopolymers or copolymers of ethylene with wide bimodal or multimodal like molecular weight distributions, wherein ethylene, alone or with an alpha olefin, is polymerized in the presence of a catalyst system within a reaction vessel wherein the catalyst system includes:

(a) a single supported or unsupported metallocene catalyst being a mono, or dicyclopentadienyl of transition metals in any of groups 4b, 5b, 6b of the Periodic Table of elements represented by the formulae:
(C5R′m)pR″s(C5R′m)MeQ3-p
or
R″s(C5R′m)2MeQ′
where (C5R′m) is cyclopentadienyl or substituted cyclopentadienyl, each R′ may be the same or different and may be hydrogen, monohydrocarbon radicals selected from the group consisting alkyl, alkenyl, aryl, alkylaryl or arylalkyl containing from 1 to 20 carbon atoms, or two adjacent carbon atoms joined to form a C4-C6 ring, where R″ is an alkylene radical containing from 1 to 4 carbon atoms, a dialkyl germanium, a dialkyl silicon radical or an alkylphosphine or amino radical joining two (C5R′m)rings, Q is a hydrocarbon radical selected from the group consisting of aryl, alkyl, alkenyl, alkylaryl, and arylalkyl containing from 1 to 20 carbon atoms, optionally halogen, and each of said hydrocarbon radicals may be the same or different, Q′ is an alkylidine radical containing from 1 to 20 carbon atoms, Me is a transition metal in groups 4b, 5b or 6b of the Periodic Table of elements, s is 0 or 1, p is 0, 1 or 2;
when p is 0, s is 0;
m is 4 if s is 1 and m is 5 if s is 0;
(b) a co-catalyst formed by a combination of an aluminum compound having Al—O bonds corresponding to the formulae:
(RAlO)n
or
(R—Al—O)nAlR2
where R is an alkyl or aryl group containing from 1 to 20 carbon atoms, and n is a number from 1 to 20, and at least one Boron compound corresponding to the general formulae:
BX1X2X3
or
(Y) (BX1X2X3X4)
where B is boron, and X1, X2, X3, X4 are the same or different and may be hydride, halide, alkyl containing from 1 to 20 carbon atoms, substituted alkyls containing from 1 to 20 carbon atoms in which one or more hydrogens are substituted by halogens, metal hydrocarbon radicals(organometalloids) in which each substitution contains from 1 to 20 carbon atoms, and the metal is selected from the group consisting of group 4a of the Periodic Table of elements, aryl, and substituted aryls containing from 6 to 20 carbon atoms and Y is a Bronsted acid, optionally in the presence of at least one alkyl aluminum of formula
AlR″′3
where the R″′ groups, which may be the same or different, may be alkyls or aryls containing from 1 to 20 carbon atoms or halogens, and Al is aluminum, and
wherein the catalyst and co-catalyst are present within a reaction vessel.

16 more elements

A process for obtaining homopolymers of or copolymers of ethylene with wide bimodal or multimodal molecular weight distributions, wherein ethylene, optionally with another alpha olefin, is polymerized in the presence of a catalyst system which consists of

(a) a supported metallocene catalyst being mono, di or tricyclopentadienyl of transition metals in any of groups 4b, 5b, 6b of the Periodic Table of elements represented by the formulae:
(C5R′m)pR″s(C5R′m)MeQ3-p
or
R″s(C5R′m)2MeQ′
where (C5R′m) is cyclopentadienyl or substituted cyclopentadienyl, each R′ may be the same or different and may be hydrogen, monohydrocarbon radicals selected from the group consisting of alkyl, alkenyl, aryl, alkylaryl or arylalkyl containing from 1 to 20 carbon atoms, or two adjacent carbon atoms joined to form a C4-C6 ring, where R″ is an alkylene radical containing from 1 to 4 carbon atoms, a dialkyl germanium, a dialkyl silicon radical or an alkylphosphine or amino radical joining two (CtR′m) rings, Q is a hydrocarbon radical selected from the group consisting of aryl, alkyl, alkenyl, alkylaryl and arylalkyl containing from 1 to 20 carbon atoms, optionally halogen, and each of said hydrocarbon radicals may be the same or different, Q′ is an alkylidine radical containing from 1 to 20 carbon atoms, Me is a transition metal in groups 4b, 5b or 6b of the Periodic Table of elements, s is 0 or 1, p is 0, 1 or 2;
when p is 0, s is 0;
m is 4 if s is 1 and m is 5 if s is 0;
(b) a co-catalyst formed by a combination of an aluminoxane compound corresponding to the formulae:
(RAlO)n
or
R(R—Al—O)nAlR2
where R is an alkyl or aryl group containing from 1 to 20 carbon atoms, and n is a number from 1 to 20, and
at least one Boron compound corresponding to the general formulae:
BX1X2X3
or
(Y) (BX1X2X3X4)
where B is boron, and X1, X2, X3, X4 are the same or different and may be hydride, halide, alkyl containing from 1 to 20 carbon atoms, substituted alkyls containing from 1 to 20 carbon atoms in which one or more hydrogens are substituted by halogens, metal hydrocarbon radicals (organometalloids) in which each substitution contains from 1 to 20 carbon atoms, and the metal is selected from the group consisting of group 4a of the Periodic Table of elements, aryl, and substituted aryls containing from 6 to 20 carbon atoms and Y is a Bronsted acid optionally in the presence of at least one alkyl aluminium of formula
AlR″′3
where the R″′groups, which may be the same or different, may be alkyls or aryls containing from 1 to 20 carbon atoms or halogens, and Al is aluminium.

16 more elements

(a) a single supported or unsupported metallocene catalyst being a mono, or dicyclopentadienyl of transition metals in any of groups 4b, 5b, 6b of the Periodic Table of elements represented by the formulae:
(C5R′m)pR″s(C5R′m)MeQ3-p
or
R″s(C5R′m)2MeQ′
where (C5R′m) is cyclopentadienyl or substituted cyclopentadienyl, each R′ may be the same or different and may be hydrogen, monohydrocarbon radicals selected from the group consisting alkyl, alkenyl, aryl, alkylaryl or arylalkyl containing from 1 to 20 carbon atoms, or two adjacent carbon atoms joined to form a C4-C6 ring, where R″ is an alkylene radical containing from 1 to 4 carbon atoms, a dialkyl germanium, a dialkyl silicon radical or an alkylphosphine or amino radical joining two (C5R′m)rings, Q is a hydrocarbon radical selected from the group consisting of aryl, alkyl, alkenyl, alkylaryl, and arylalkyl containing from 1 to 20 carbon atoms, optionally halogen, and each of said hydrocarbon radicals may be the same or different, Q is an alkylidine radical containing from 1 to 20 carbon atoms, Me is a transition metal in groups 4b, 5b or 6b of the Periodic Table of elements, a is 0 or 1, p is 0, 1 or 2;
when p is 0, s is 0;
m is 4 if s is 1 and m is 5 if e is 0;
(b) a co-catalyst formed by a combination of an aluminoxane compound corresponding to the formulae:
(RAlO)n
or
R(R—Al—O)nAlR2
where R is an alkyl or aryl group containing from 1 to 20 carbon atoms, and n is a number from 1 to 20, and at least one Boron compound corresponding to the general formulae:
BX1X2X3
or
(Y) (BX1X2X3X4)
where B is Boron, and X1, X2, X3, X4 are the same or different and may be hydride, halide, alkyl containing from 1 to 20 carbon atoms, substituted alkyls containing from 1 to 20 carbon atoms in which one or more hydrogens are substituted by halogens, metal hydrocarbon radicals(organometalloids) in which each substitution contains from 1 to 20 carbon atoms, and the metal is selected from the group consisting of group 4a of the Periodic Table of elements, aryl, and substituted aryls containing from 6 to 20 carbon atoms and Y is a Bronsted acid, optionally in the presence of at least one alkyl aluminum of formula
AlR″′3
where the R″′groups, which may be the same or different, may be alkyls or aryls containing from 1 to 20 carbon atoms or halogens, and Al is aluminum, and
wherein the catalyst and co-catalyst are present within a reaction vessel.

16 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/580,734Filed 28 Dec 1995
Priority: ES 940269030 Dec 1994
Granted: 12 Aug 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

C08F 10/00
Homopolymers and copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double
C08F 4/61908
Component covered by group C08F4/60 containing a transition metal-carbon bond: in combination with an ionising compound other than alumoxane, e.g.…
C08F 4/61912
Component covered by group C08F4/60 containing a transition metal-carbon bond: in combination with an organoaluminium compound
C08F 4/61916
Component covered by group C08F4/60 containing a transition metal-carbon bond: supported on a carrier, e.g. silica, MgCl2, polymer