Process for preparing in a single reactor polymer blends having a broad molecular weight distribution
AssigneeDuPont Dow Elastomers L.L.C.
InventorsMichael K. Laughner, Debra J. Mangold, Deepak R. Parikh
Life of this patent
Estimating the term…
Abstract
Ethylene-based polymer blends having an MWD of at least about 2 are made in a single reactor using a mixed constrained geometry catalyst (CGC) system. The process comprises the steps of contacting under polymerization conditions and in a single reaction vessel (i) ethylene, (ii) at least one C3-C20 α-olefin, (iii) optionally, at least one polyene, and (iv) a mixed CGC system.
Claims14
An ethylene-based polymer blend made with a mixed catalyst system comprising a first and a second catalyst, the blend having (a) a molecular weight distribution (i) of at least about 2, and (ii) at least about ten percent greater than that of a polymer prepared in a single reactor with either the first or second catalyst alone under similar polymerization conditions, and (b) a uniform molecular architecture, the blend made by a process comprising contacting under polymerization conditions and in a single reaction vessel:
- A. ethylene
- B. at least one C3-C20 α-olefin, and
- C. the mixed catalyst system comprising the first catalyst and the second catalyst, and each catalyst comprising:
- 1. a metal complex of formula I
- ZLMXpX′q (I)
- wherein M is a metal of Group 4 of the Periodic Table of the Elements having an oxidation state of +2, +3 or +4 bound in an η5 bonding mode to L;
- L is a cyclopentadienyl-, indenyl-, tetrahydroindenyl-, fluorenyl-, tetrahydrofluorenyl-, or octahydrofluorenyl-group covalently substituted with at least the divalent moiety, Z, and L further may be substituted with from 1 to 8 substituents independently selected from the group consisting of hydrocarbyl, halo, halohydrocarbyl, hydrocarbyloxy, dihydrocarbylamine, dihydrocarbylphosphino or silyl groups containing up to 20 nonhydrogen atoms;
- Z is a divalent moiety, or a moiety comprising one σ-bond and a neutral two electron pair able to form a coordinate-covalent bond to M, Z comprising boron, or a member of Group 14 of the Periodic Table of the Elements, and also comprising nitrogen, phosphorus, sulfur or oxygen;
- X is a anionic ligand group having up to 60 atoms exclusive of the class of ligands that are cyclic, delocalized, π-bound ligand groups;
- X′ independently each occurrence is a neutral ligating compound having up to 20 atoms;
- p is 0, 1 or 2, and is two less than the formal oxidation state of M, with the proviso that when X is a dianionic ligand group, p is 1;
- and
- q is 0, 1 or 2;
- and
- 2. an activating cocatalyst;
- with the provisos that
- D. the first catalyst is different from the second catalyst, and
- E. the weight ratio of the first catalyst to the second catalyst, based on the weight of the metal M in each catalyst, is between about 90:10 and 10:90.
An ethylene-based polymer blend made with a mixed catalyst system comprising a first and second catalyst, the blend having an MWD (a) of at least about 2, and (b) at least ten percent greater than any ethylene-based polymer component of the blend prepared in a single reactor with any single catalyst of the mixed catalyst system under similar polymerization conditions, the blend made by a process comprising contacting under polymerization conditions and in a single reaction vessel:
- A. ethylene,
- B. at least one C3-C20 α-olefin,
- C. at least one polyene, and
- D. a mixed catalyst system comprising a first catalyst and a second catalyst, each catalyst having substantially the same reactivity ratio with respect to at least one C3-C20 α-olefin of B, and each catalyst comprising:
- 1. A metal complex of formula I,
- ZLMXpX′q (I)
- wherein M is a metal of Group 4 of the Periodic Table of the Elements having an oxidation state of +2, +3 or +4 bound in an η5 bonding mode to L;
- L is a cyclopentadienyl-, indenyl-, tetrahydroindenyl-, fluorenyl-, tetrahydrofluorenyl-, or octahydrofluorenyl-group covalently substituted with at least the divalent moiety, Z, and L further may be substituted with from 1 to 8 substituents independently selected from the group consisting of hydrocarbyl, halo, halohydrocarbyl, hydrocarbyloxy, dihydrocarbylamine, dihydrocarbylphosphino or silyl groups containing up to 20 nonhydrogen atoms;
- Z is a divalent moiety, or a moiety comprising one α-bond and a neutral two electron pair able to form a coordinate-covalent bond to M, Z comprising boron, or a member of Group 14 of the Periodic Table of the Elements, and also comprising nitrogen, phosphorus, sulfur or oxygen;
- X is a anionic ligand group having up to 60 atoms exclusive of the class of ligands that are cyclic, delocalized, π-bound ligand groups;
- X′ independently each occurrence is a neutral ligating compound having up to 20 atoms;
- p is 0, 1 or 2, and is two less than the formal oxidation state of M, with the proviso that when X is a dianionic ligand group, p is 1;
- and
- q is 0, 1 or 2;
- and
- 2. an activating cocatalyst;
- with the provisos that
- E. the first catalyst is different from the second catalyst, and
- F. the weight ratio of the first catalyst to the second catalyst, based on the weight of the metal M in each catalyst, is between about 90:10 and 10:90.
Dependencies are inferred from the claim text.