4714 results about "Olefin polymerization" patented technology

This invention relates to the field of olefin polymerization catalyst compositions, and methods for the polymerization and copolymerization of olefins, typically using a supported catalyst composition. In one aspect, this invention encompasses precontacting a metallocene with an olefin or alkyne monomer and an organoaluminum compound, prior to contacting this mixture with the acidic activator-support.

A composition for use in forming a multi-block copolymer, said copolymer containing therein two or more segments or blocks differing in chemical or physical properties, a polymerization process using the same, and the resulting polymers, wherein the composition comprises the admixture or reaction product resulting from combining: (A) a first metal complex olefin polymerization catalyst, (B) a second metal complex olefin polymerization catalyst capable of preparing polymers differing in chemical or physical properties from the polymer prepared by catalyst (A) under equivalent polymerization conditions, and (C) a chain shuttling agent.

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 10x 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° C., preferably above 100° C., including in the range of from about 120° C. to about 140° C. and above. Novel flexible alpha-olefin homo and copolymers having elongation in excess of 600% and substantially no retained force are disclosed.

This invention relates to the field of olefin polymerization catalyst compositions, and methods for the polymerization and copolymerization of olefins, including polymerization methods using a supported catalyst composition. In one aspect, the present invention encompasses a catalyst composition comprising the contact product of at least one metallocene compound, at least one organochromium compound, at least one chemically-treated solid oxide, and at least one organoaluminum compound.

An organometallic compound obtainable by contactinga) a compound having the following formula (I):wherein Ra, Rb, Rc and Rd equal to or different from each other are hydrocarbon groupsb) a Lewis acid of formula (II)wherein Mt is a metal belonging to Group 13 of the Periodic Table of the Elements (IUPAC); R1, equal to or different from each other, are selected from the group consisting of halogen, halogenated C6-C20 aryl and halogenated C7-C20 alkylaryl groups; two R1 groups can also form with the metal Mt one condensed ring.These compounds are useful as cocatalysts for polymerizing olefins.

A process for the polymerization of one or more addition polymerizable monomers and the resulting polymer products, said process comprising: 1) contacting an addition polymerizable monomer or mixture of monomers under addition polymerization conditions in a reactor or reactor zone with a composition comprising at least one olefin polymerization catalyst and a cocatalyst and characterized by the formation of polymer chains from said monomer or monomers; 2) transferring the reaction mixture to a second reactor or reactor zone and optionally adding one or more additional reactants, catalysts, monomers or other compounds prior to, commensurate with, or after said transfer; and 3) causing polymerization to occur in said second reactor or reactor zone to form polymer chains that are differentiated from the polymer chains formed in step 1); said process being characterized by addition of a chain shuttling agent to the reaction mixture prior to, during, or subsequent to step 1) such that at least some of the resulting polymer molecules from step 3) comprise two or more chemically or physically distinguishable blocks or segments.

A class of metallocene compounds is disclosed having general formula (I) wherein Y is a moiety of formula (II) wherein A, B, and D, same or different from each other, are selected from an element of the groups 14 to 16 of the Periodic Table of the Elements (new IUPAC version), with the exclusion of nitrogen and oxygen; R<1>, R<2>, R<3>, R<4 >and R<5 >are hydrogen or hydrocarbon groups, Z is selected from a moiety of formula (II) as described above and from a moiety of formula (III) wherein R<6>, R<7>, R<8 >and R<9>, are hydrogen or hydrocarbon groups; L is a divalent bridging group; M is an atom of a transition metal selected from those belonging to group 3, 4, 5, 6 or to the lanthanide or actinide groups in the Periodic Table of the Elements (new IUPAC version), X, same or different, is hydrogen, a halogen, a R<10>, OR<10>, OSO2CF3, OCOR<10>, SR<10>, NR<10>2 or PR<10>2 group, wherein the substituents R<10 >are hydrogen or alkyl groups; p is an integer of from 1 to 3, being equal to the oxidation state of the metal M minus 2. The above metallocenes are particularly useful in the polymerization of propylene.