摘要:
A process for preparing low melting copolymers comprising contacting a mixture of olefin monomers with a CpFlu-type metallocene catalyst under reaction conditions sufficient to form a copolymer. The copolymers thus prepared desirably display melt temperatures from about 100° C. to about 140° C. and may be produced with reduced amounts of ethylene. The copolymers may also exhibit reduced levels of undesirable xylene solubles, relatively narrow molecular weight distribution, and other improved optical and physical properties.
摘要:
The invention is directed to a metallocene catalyst system comprising an inert silica support having pores with a peak pore volume of greater than about 0.115 mL/g at a pore diameter between about 250 Angstroms and about 350 Angstroms, and an alumoxane activator, with the metallocene being bound substantially throughout the support. The activator is grafted to the support in a solvent at a reflux temperature of toluene to obtain an aluminoxane on silica, and a metallocene component is added to make a MCS having a metallocene loading of about 2 wt %. This facilitates the production of metallocene catalyst systems having increased catalytic activity than previously recognized that is at least about 20 percent higher than the catalytic activity for a metallocene loading of about 1 wt % where the activator is grafted to the support at room temperature.
摘要:
The invention is directed to a metallocene catalyst system comprising an inert silica support having pores with a peak pore volume of greater than about 0.115 mL/g at a pore diameter between about 250 Angstroms and about 350 Angstroms, and an alumoxane activator, with the metallocene being bound substantially throughout the support. The activator is grafted to the support in a solvent at a reflux temperature of toluene to obtain an aluminoxane on silica, and a metallocene component is added to make a MCS having a metallocene loading of about 2 wt %. This facilitates the production of metallocene catalyst systems having increased catalytic activity than previously recognized that is at least about 20 percent higher than the catalytic activity for a metallocene loading of about 1 wt % where the activator is grafted to the support at room temperature.
摘要:
The invention is directed to a metallocene catalyst system and a process for preparing the system. The metallocene catalyst system comprises a support and metallocene bound substantially throughout the support. The selection of certain supports facilitates the production of metallocene catalyst systems having increased catalytic activity than previously recognized.
摘要:
Random copolymers may be prepared using a process that includes polymerizing a mixture of monomers including at least propylene and ethylene monomer, in the presence of a catalyst system including a metallocene catalyst having the general structure: racemic-X(2-R1-4-R2-Ind)2MCl2 wherein M is a Group 4, 5 or 6 transition metal, or a lanthanide or actinide series metal; X is a structural bridge imparting stereorigidity; R1 is hydrogen or an alkyl, aryl or a substitution moiety; R2 is hydrogen, or a C1-C4 alkyl; and Ind is an indenyl group. The copolymers are prepared under reaction conditions suitable to form a copolymer, wherein the copolymer has a higher level of ethylene incorporation than a corresponding polymer formed under otherwise identical reaction conditions except that a different bisindeny metallocene catalyst having a 4-indenyl substitution larger than 4 carbons is used. The copolymers may have a lower melt temperature than the corresponding polymers. The resulting copolymers may be used to prepare articles of manufacture including, but not limited to films, fibers and injection molded articles.
摘要:
Catalyst systems and methods of forming the catalyst systems are described herein. The methods generally include contacting a support material with an activator to form a support composition, contacting a component with at least a portion of an aluminum containing compound including TIBAl, wherein the component is selected from the support composition, the transition metal catalyst compound and combinations thereof and contacting the support composition with a transition metal catalyst compound to form a supported catalyst system.
摘要:
Supported stereospecific catalysts and processes for the stereotactic propagation of a polymer chain derived from ethylenically unsaturated monomers such as the polymerization of propylene to produce syndiotactic polypropylene or isotactic polypropylene. The supported catalyst comprises a stereospecific metallocene catalyst component and a co-catalyst component comprising an alkylalumoxane. Both the metallocene catalyst component and the co-catalyst component are supported on a particulate polyamide support comprising spheroidical particles of a polyamide having an average diameter with the range of 5-60 microns, and a porosity permitting distribution of a portion of the co-catalyst within the pore volume of the polyamide particles while retaining a substantial portion on the surface of the particles. The polyamide support is characterized by relatively low surface area, specifically a surface area less than 20 square meters per gram. The metallocene component can take the form of a single metallocene or two or more co-supported metallocenes.
摘要:
Supported stereospecific catalysts and processes for the stereotactic propagation of a polymer chain derived from ethylenically unsaturated monomers such as the polymerization of propylene to produce syndiotactic polypropylene or isotactic polypropylene. The supported catalyst comprises a stereospecific metallocene catalyst component and a co-catalyst component comprising an alkylalumoxane. Both the metallocene catalyst component and the co-catalyst component are supported on a particulate polyamide support comprising spheroidical particles of a polyamide having an average diameter with the range of 5-60 microns, and a porosity permitting distribution of a portion of the co-catalyst within the pore volume of the polyamide particles while retaining a substantial portion on the surface of the particles. The polyamide support is characterized by relatively low surface area, specifically a surface area less than 20 square meters per gram. The metallocene component can take the form of a single metallocene two or more co-supported metallocenes.
摘要:
Catalyst systems and methods of forming the catalyst systems are described herein. The methods generally include contacting a support material with an activator to form a support composition, contacting a component with at least a portion of an aluminum containing compound including TIBAl, wherein the component is selected from the support composition, the transition metal catalyst compound and combinations thereof and contacting the support composition with a transition metal catalyst compound to form a supported catalyst system.
摘要:
Catalyst systems and methods of forming the catalyst systems are described herein. The methods generally include contacting a support material with an activator to form a support composition, contacting a component with at least a portion of an aluminum containing compound including TIBAl, wherein the component is selected from the support composition, the transition metal catalyst compound and combinations thereof and contacting the support composition with a transition metal catalyst compound to form a supported catalyst system.