摘要:
Process of preparing silica-supported catalysts. A support material comprising silica particles impregnated with an alumoxane co-catalyst with at least one-half of the co-catalyst disposed within the internal pore volume of the silica is contacted with a dispersion of a metallocene catalyst in an aromatic solvent. The dispersion and support are mixed at a temperature of about 10° C. or less to enable the metallocene to become reactively supported on and impregnated within the alumoxane-impregnated silica particles. The supported catalyst is recovered from the aromatic solvent and washed with an aromatic hydrocarbon and then a paraffinic hydrocarbon at a temperature of about 10° C. or less. The washed catalyst is dispersed in a viscous mineral oil.
摘要:
A process for the preparation of a supported metallocene catalyst incorporating metallocene and co-catalysts components on a support. There is provided a particulate catalyst support material in which an alumoxane co-catalyst is incorporated onto the support particles and contacted with a dispersion of a metallocene catalyst in an aromatic hydrocarbon solvent. The metallocene solvent dispersion and the alumoxane-containing support are mixed at a temperature of about 10° C. or less for a period sufficient to enable the metallocene to become reactively supported on the alumoxane support material. The supported catalyst is recovered from the aromatic solvent and then washed optionally with an aromatic hydrocarbon and then sequentially with a paraffinic hydrocarbon solvent at a temperature of about 10° C. or less. The washed catalyst is dispersed in a viscous mineral oil having a viscosity which is substantially greater that the viscosity of the paraffinic hydrocarbon solvent.
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:
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 polyorganosilsesquioxane support comprising spheroidal particles of a polyorganosilsesquioxane having an average. diameter with the range of 0.3–20 microns. The polyorganosilsesquioxane support is characterized by relatively low surface area, specifically a surface area less than 100 square meters per gram. The metallocene component can take the form of a single metallocene or two or more metallocenes which are co-supported on the polyorganosilsesquioxane support.
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:
The present invention generally relates to polymeric compositions capable of providing enhanced crosslinking efficiency, to single and multilayer films having the subject composition contained within at least one layer of said film, to a method of treating said film to provide enhanced crosslink within said at least one layer of the film and to the resultant cross-linked film product as well as articles made from said cross-linked film product.
摘要:
A composition capable of scavenging oxygen composed of (i) a copolymer having long chain branches comprising units derived from monomers of ethylene and at least one vinyl unsaturated alicyclic monomer; (ii) a transition metal catalyst; (iii) preferably, with a photoinitiator; and (iv) optionally, a polymeric diluent.
摘要:
The subject invention is directed to new and novel copolymers having long chain branches formed from ethylene and at least one vinyl alicyclic monomer, to solution polymerization using certain unstrained bridged metallocene catalyst which has been found capable of forming said copolymers and to packaging material formed therefrom.
摘要:
A composition capable of scavenging oxygen composed of (i) a copolymer having long chain branches comprising units derived from monomers of ethylene and at least one vinyl unsaturated alicyclic monomer; (ii) a transition metal catalyst; (iii) preferably, with a photoinitiator; and (iv) optionally, a polymeric diluent.