Polymerization catalysts for producing polymers with low melt elasticity
AssigneeChevron Phillips Chemical Company LP
InventorsQing Yang, Max P. McDaniel, Joel L. Martin, Youlu Yu, David C. Rohlfing, Michael D. Jensen
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Abstract
The present techniques relate to catalyst compositions, methods, and polymers encompassing a Group 4 metallocene compound comprising bridging η5-cyclopentadienyl-type ligands, typically in combination with a cocatalyst, and a activator. The compositions and methods presented herein include ethylene polymers with low melt elasticity.
Claims20
An ansa-metallocene comprising a compound having the formula:
- wherein:
- M1 is zirconium or hafnium;
- X′ and X″ are independently F, Cl, Br, I, H, BH4, methyl, phenyl, benzyl, neopentyl, trimethylsilylmethyl, CH2CMe2Ph, CH2SiMe2Ph, CH2CMe2CH2Ph, or CH2SiMe2CH2Ph;
- E is C or Si;
- R1 and R2 are independently an alkyl group, an aryl group, or hydrogen;
- R3A and R3B are independently a hydrocarbyl group, a trihydrocarbylsilyl group, or hydrogen;
- n is an integer from 0 to 10, inclusive;
- and
- R4A and R4B are independently a hydrocarbyl group.
A method of producing an ansa-metallocene, comprising:
- reacting an ansa-metallocene ligand having the formula:
- with a base to generate a respective intermediate;
- and
- reacting the respective intermediate with ZrCl4 to generate the ansa-metallocene having the formula:
- or
- reacting the respective intermediate generated by the reaction between the base and the ansa-metallocene ligand, wherein the ansa-metallocene ligand has the formula:
- with HfCl4 to generate the ansa-metallocene having the formula:
An ansa-metallocene ligand comprising a compound having the formula:
- wherein:
- E is C or Si;
- R1 and R2 are independently an alkyl group, an aryl group, or hydrogen;
- R3A and R3B are independently a hydrocarbyl group, a trihydrocarbylsilyl group, or hydrogen;
- n is an integer from 0 to 10, inclusive;
- and
- R4A and R4B are independently a hydrocarbyl group.
An ansa-metallocene having a formula of:
Dependencies are inferred from the claim text.