摘要:
Disclosed herein are catalyst compositions and polymers, i.e., propylene-based polymers, produced therefrom. The present catalyst compositions contain an internal electron donor of an alkoxyalkyl 2-propenoate and optionally a mixed external electron donor. The present catalyst compositions improve catalyst selectivity and polymer stiffness. Polypropylene homopolymer produced from the present catalyst composition has a xylene solubles content less than 4 wt % and a TMF greater than 172.0° C.
摘要:
The present invention provides polymerization processes utilizing an ansa-metallocene catalyst system for the production of olefin polymers. Polymers produced from the polymerization processes have properties that vary based upon the presence or the absence of hydrogen and/or comonomer in the polymerization process.
摘要:
A method of forming a polymer includes a step of polymerizing a compound having formula 1 with a Ziegler-Natta catalyst to form a polymer having formula 2: wherein: R is a fluorinated C1-18 alkyl group, a fluorinated ether group, or a fluorinated silane ether; and n is a number from about 20 to 500 on average.
摘要:
Activating supports may be suitably prepared by (a) combining (i) fluorine-containing compounds having a reactive group and (ii) an organometallic compound, (b) addition of a porous mineral oxide support material, (c) heating the functionalized support from step (b) under an inert gas and then under an atmosphere comprising oxygen, and (d) recovering the activating support. The preferred fluorine-containing compounds have the formula: R(Fn)-X wherein R is hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl or substituted heterohydrocarbyl with up to 20 non-hydrogen atoms, n is 1-41, X is OH, SH or NR′2, R′ is hydrogen or hydrocarbyl. The activating supports are suitable used in combination with transition metal catalysts for the polymerization of olefins. The supports are most preferable used in combination with metallocene complexes. The preparative route for the activating supports is easier and more economic than prior art methods and also provides for supported polymerization catalyst systems having excellent activities. Polymers produced by use of the activating supports exhibit improved rheology properties.
摘要:
Supported catalyst system for the polymerization of olefins, having at least two different monocyclopentadienyl transition metal compounds, one or more activators including an ionic compound having (i) a cation and (ii) an anion having up to 100 non-hydrogen atoms and the anion containing at least one substituent comprising a moiety having an active hydrogen, and one or more support materials. The supported “mixed or dual site” catalyst systems having different monocyclopentadienyl catalysts when activated by specific ionic activators lead to catalyst systems showing an improved balance of properties which may be used to prepare LLDPE polymers having broad melt flow ratios.
摘要:
Methods for gas phase olefin polymerization are provided. The method can include combining a spray dried catalyst system with a diluent to produce a catalyst slurry. The catalyst system can include a metallocene compound. Ethylene, a continuity additive, and the catalyst slurry can be introduced to a gas phase fluidized bed reactor. The reactor can be operated at conditions sufficient to produce a polyethylene. The spray dried catalyst system can have a catalyst productivity of at least 12,000 grams polyethylene per gram of the catalyst system.
摘要:
Novel group 4 organometallic compounds, supported on anions by means of at least one covalent metal-oxygen bond, are obtained by reaction of at least one borate or aluminum comprising at least one hydroxy group with at least one group 4 transition metal compound. These compounds are used in a catalytic composition implemented in an olefin oligomerization or polymerization method.
摘要:
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 a first metallocene compound, a second metallocene compound, at least one chemically-treated solid oxide, and at least one organoaluminum compound. The new resins were characterized by useful properties in impact, tear, adhesion, sealing, extruder motor loads and pressures at comparable melt index values, and neck-in and draw-down.
摘要:
A catalyst composition comprising one or more metal complexes of a multifunctional Lewis base ligand comprising a bulky, planar, aromatic- or substituted aromatic-group and polymerization processes employing the same, especially continuous, solution polymerization of one or more α-olefins at high catalyst efficiencies are disclosed.
摘要:
Method for the preparation of a blown film containing 300-600 gels/m2 of size in the range 100-2000 μm as measured by an optical control system, in which the film is derived by extrusion from an ethylene-α-olefin copolymer. The method is carried out by preparing the copolymer in a particle forming polymerization process in the presence of a single site catalyst system containing a single site catalyst, a cocatalyst, and a support material.