Leland Stanford Junior University

Raisa L Kravchenko

Robert M Waymouth

Charles L Myers

Eric J Moore

Roger W Quan

Andreas B Ernst

Larry L Bendig

Jennifer Maciejewski Petoff

Joyce Hung

Jennifer L Maciejewski Petoff

A metallocene catalyst system component for polymerization of olefins includes at least one 2-arylindenyl ligand substituted on the 1-position by a substituted or unsubstituted alkyl, alkylsilyl, or aryl substituent of 1 to 30 carbon atoms.

Catalyst systems for high melting thermoplastic elastomeric &#x3b1;-olefin polymers and plastomers

This invention relates generally to low ethylene insertions into I-olefin polymers and processes for production of such polymers using unbridged fluxional metallocenes, primarily substituted aryl indenyl metallocenes, and more particularly to use of unbridged, fluxional, cyclopentadienyl or indenyl metallocene catalyst systems in methods of production of high melting point I-olefin homo- and co-polymers, particularly elastomeric crystalline and amorphous block homo- and co-polymers of I-olefins. The activity of fluxional unbridged metallocene polymerization catalysts containing at least one 2-arylindene ligand is increased 10&times; or more by the addition of small (typically 0.1-10 wt. %) amounts of ethylene to the polymerization system, which increase is termed the Polymerization Rate-Enhancement effect (PRE), which is measured in terms of an Ethylene Enhancement Factor (EEF) as a dimensionless ratio in the range of from about 1.1 to about 10 or above. The amount of ethylene included in the reaction system can be selected and controlled to be so small as to result in essentially minimal (<2 mole %) incorporation of ethylene units into the resulting elastomeric polymer and the molecular weight may be increased. Amounts of ethylene to generate the PRE effect may be greater than 0.1 wt. % and preferably range up to about 2 wt. %. However, if a polymer with more ethylene is desired, additional ethylene may be incorporated into the polymerization feed, including up to 10 to about 50 mole % based on olefin units. A second important aspect of this invention is the ability to use a PRE activity-enhancing amount of ethylene in an olefin polymerization without substantially affecting the physical properties of the elastomer. In a third important aspect of this invention, I-olefin elastomers are produced through incorporation of ethylene using unbridged fluxional catalyst systems which may not otherwise produce acceptable elastomeric homopolymers. This effect is termed the EPE effect, for Elastomeric Property-Enhancing effect. The EPE amount of ethylene required to produce such elastomers typically overlaps the PRE activity-enhancing amount. Incorporation of up to about 5 mole % or more of ethylene typically will produce an elastomeric polymer using such catalyst systems. Typical useful amounts of incorporated ethylene include about 1 to 3 mole %. Preferred polymers of this invention retain sufficient crystallinity to provide a high melting point (by DSC) of about 80&deg; C., preferably above 100&deg; C., including in the range of from about 120&deg; C. to about 140&deg; C. and above. Novel flexible &agr;-olefin homo and copolymers having elongation in excess of 600% and substantially no retained force are disclosed.

High melting thermoplastic elastomeric alpha-olefin polymers (PRE/EPE effect) and catalysts therefor

This invention relates to high melting polyolefin copolymers suitable as thermoplastic elastomers and catalysts and methods for their synthesis. These elastomeric olefin copolymers are characterized by a mole fraction of crystallizable component X from about 30 to about 99%; low glass transition temperatures, below &minus;20&deg; C., and typically below &minus;50&deg; C.; melting points above about 90&deg; C.; high molecular weights; a molecular weight distribution M /M </&equals;10; and a narrow composition distribution between chains of </&equals;15%. The novel copolymers of the invention range from reactor blends to multiblock copolymers that can be sequentially fractionated into fractions of differing crystallinities, which fractions nevertheless show compositions of comonomers which differ by less than 15% from the parent polymer (reactor product). The invention also relates to a process for producing such copolymers by utilizing an unbridged, substituted or unsubstituted cyclopentadienyl metallocene catalyst that is capable of interconverting between states with different copolymerization characteristics, which interconversion is controlled by selecting the substituents of the cyclopentadienyl ligands so that the rate of interconversion of the two states is within several orders of magnitude of the rate of formation of a single polymer chain. Where r >r the polymer can be characterized as multiblock; where r <r , the result is a polymer blend and where r / r is close to 1, the resulting polymer is a mixture of blend and multiblock. The metallocene catalysts of the invention are able to interconvert between more than two states, with embodiments of four states being shown in FIG.

High-melting polyolefin copolymer elastomers, catalysts and methods of synthesis

Metallocene catalysts having plural coordination geometries for synthesis of high melting polyolefin copolymers suitable as thermoplastic elastomers. The inventive catalysts comprise unbridged, substituted or unsubstituted cyclopentadienyl metallocene catalysts that are capable of inter-converting between states with different polymerization or copolymerization characteristics, which interconversion is controlled by selecting the substituents of the cyclopentadienyl ligands so that the rate of interconversion of the two states is within several orders of magnitude of the rate of formation of a single polymer chain. Where r >r the polymer can be characterized as multiblock; where r <r , the result is a polymer blend and where r /r is close to 1, the resulting polymer is a mixture of blend and multiblock. The inventive metallocene catalysts are able to interconvert between more than two states, with embodiments of four states being shown in FIG.

Metallocene catalysts for synthesis of high-melting polyolefin copolymer elastomers

A copolymer of ethylene and at least one comonomer containing at least 4 carbon atoms is characterized by a polydispersity greater than 2, a broad melting point transition as measured by differential scanning calorimetry, and a narrow composition distribution. Ethylene/C copolymers also may show at least one peak melting point above the peak melting point of a random copolymer of the same monomer unit composition. These copolymers are made by contacting ethylene and a comonomer under polymerization conditions in the presence of a suitable fluxional catalyst system.

Ethylene copolymers with narrow composition distribution and high melting temperatures, and methods of production thereof

This invention relates to high melting polyolefin copolymers suitable as thermoplastic elastomers and catalysts and methods for their synthesis. These elastomeric olefin copolymers are characterized by a mole fraction of crystallizable component X,from about 30 to about 99%; low glass transition temperatures, below &minus;20&deg; C., and typically below &minus;50&deg; C.; melting points above about 90&deg; C.; high molecular weights; a molecular weight distribution M,/M,</&equals;10; and a narrow composition distribution between chains of </&equals;15%. The novel copolymers of the invention range from reactor blends to multiblock copolymers that can be sequentially fractionated into fractions of differing crystallinities, which fractions nevertheless show compositions of comonomers which differ by less than 15% from the parent polymer (reactor product). The invention also relates to a process for producing such copolymers by utilizing an unbridged, substituted or unsubstituted cyclopentadienyl metallocene catalyst that is capable of interconverting between states with different copolymerization characteristics, which interconversion is controlled by selecting the substituents of the cyclopentadienyl ligands so that the rate of interconversion of the two states is within several orders of magnitude of the rate of formation of a single polymer chain. Where r,>r,the polymer can be characterized as multiblock; where r,<r,, the result is a polymer blend and where r,/r,is close to 1, the resulting polymer is a mixture of blend and multiblock. The metallocene catalysts of the invention are able to interconvert between more than two states, with embodiments of four states being shown in FIG.

This invention relates generally to low ethylene insertions into .alpha.-olefin polymers and processes for production of such polymers using unbridged fluxional metallocenes, primarily substituted aryl indenyl metallocenes, and more particularly to use of unbridged, fluxional, cyclopentadienyl or indenyl metallocene catalyst systems in methods of production of high melting point .alpha.-olefin homo- and co-polymers, particularly elastomeric crystalline and amorphous block homo- and co-polymers of .alpha.-olefins. The activity of fluxional unbridged metallocene polymerization catalysts containing at least one 2-arylindene ligand is increased 10.times. or more by the addition of small (typically 0.1-10 wt. %) amounts of ethylene to the polymerization system, which increase is termed the Polymerization Rate-Enhancement effect (PRE), which is measured in terms of an Ethylene Enhancement Factor (EEF) as a dimensionless ratio in the range of from about 1.1 to about 10 or above. A second important aspect of this invention is the ability to use a PRE activity-enhancing amount of ethylene in an olefin polymerization without substantially affecting the physical properties of the elastomer. In a third important aspect of this invention, .alpha.-olefin elastomers are produced through incorporation of ethylene using unbridged fluxional catalyst systems which may not otherwise produce acceptable elastomeric homopolymers. Preferred polymers of this invention retain sufficient crystallinity to provide a high melting point (by DSC) of about 80.degree. C., preferably above 100.degree. C., including in the range of from about 120.degree. C. to about 140.degree. C. and above. Novel flexible .alpha.-olefin homo and copolymers having elongation in excess of 600% and substantially no retained force are disclosed.

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Wilmington, DE, United States of America

Raisa L Kravchenko