Method for producing very-high or ultra-high molecular weight polyethylene
AssigneeSymyx Solutions, Inc.
InventorsGary M. Diamond, Margarete K. Leclerc, Guang Zhu
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Abstract
The field of the invention relates generally to a method for preparing very-high or ultra-high molecular weight polyethylene. More particularly, the present invention related to a method of preparing very-high or ultra-high molecular weight polyethylene using a supported catalyst comprising a support, an activator and a metal-ligand complex, as well as the catalyst itself. The present invention additionally relates to a method of using a supported catalyst comprising a support, an activator and co-supported metal-ligand complexes to obtain a bi-modal molecular weight distribution of polyethylene.
Claims11
A slurry polymerization method for producing a very-high or ultra-high molecular weight polyethylene composition, the method comprising contacting one or more monomers with a supported catalyst, the supported catalyst comprising:
- a support,
- a metal-ligand complex deposited on the support at a loading from about 1 μmol/gram of supported catalyst to about 100 μmol/gram of supported catalyst, the metal-ligand complex characterized by the general formula:
- wherein the O-AR-AR-O—B—O-AR-AR-O fragment of the general formula is defined by a ligand selected from the group consisting of
- wherein at least two of the bonds from the oxygens (O) to M are covalent, with the other bonds being dative;
- M is a metal selected from the group consisting of Hf and Zr;
- each L is independently a moiety that forms a covalent dative or ionic bond with M;
- and n′ is 1, 2, 3 or 4;
- and,
- an activator.
A slurry polymerization method for producing a very-high or ultra-high molecular weight polyethylene composition, the method comprising contacting one or more monomers with a supported catalyst, the supported catalyst comprising:
- a support,
- a metal-ligand complex deposited on the support at a loading from about 1 μmol/gram of supported catalyst to about 100 μmol/gram of supported catalyst, the metal-ligand complex characterized by the general formula:
- wherein at least two of the bonds from the oxygens (0) to M are covalent, with the other bonds being dative;
- and
- wherein each of R2 and R12 is
- each of R3, R4, R5, R6, R7, R8, R9, R13, R14, R15, R16, R17, R18 and R19 is independently selected from the group consisting of hydrogen, halogen, and optionally substituted hydrocarbyl, heteroatom-containing hydrocarbyl, alkoxy, aryloxy, silyl, boryl, phosphino, amino, alkylthio, arylthio, nitro, and combinations thereof;
- optionally two or more R groups can combine together into ring structures, with such ring structures having from 3 to 12 atoms in the ring, not counting hydrogen atoms;
- B is a bridging group having from 3 to 50 atoms not counting hydrogen atoms and is selected from the group consisting of optionally substituted divalent hydrocarbyl and optionally substituted divalent heteroatom-containing hydrocarbyl;
- M is a metal selected from the group consisting of Hf and Zr;
- each L is independently a moiety that forms a covalent dative or ionic bond with M;
- and n′ is 1, 2, 3 or 4;
- wherein the O—B—O fragment is:
- wherein each Q is independently selected from the group consisting of carbon and silicon, each R60 is independently selected from the group consisting of hydrogen and optionally substituted hydrocarbyl and heteroatom containing hydrocarbyl, provided that at least one R60 substituent is not hydrogen, wherein the R60 substituents are optionally joined into a ring structure having from 3 to 50 atoms in the ring structure not counting hydrogen atoms, and m′ is 0, 1, 2 or 3;
- and,
- an activator.
Dependencies are inferred from the claim text.