摘要:
This invention relates generally to crystalline propylene polymers, to methods for their production and to methods for their use in film applications. Specifically, this invention relates to crystalline propylene polymers comprising both propylene homopolymer and propylene copolymer. The compositions are prepared using metallocene catalyst systems comprising at least two metallocenes in a polymerization process that involves the sequential or parallel polymerization of propylene homopolymer and copolymer using propylene with a small amount of comonomer, preferably ethylene. The polymerization is catalyzed by a dual metallocene catalyst system. The resulting polymers have a broad, bimodal molecular weight distribution. The resulting polymers are excellent for use in the production of biaxially oriented films or non-oriented films. Films prepared with these propylene polymers have a significantly broader processability range and can be evenly stretched at lower temperature compared to films prepared from traditional propylene polymer.
摘要:
This invention relates generally to crystalline propylene polymers, to methods for their production and to methods for their use in film applications. Specifically, this invention relates to crystalline propylene polymers comprising both propylene homopolymer and propylene copolymer. The compositions are prepared using metallocene catalyst systems comprising at least two metallocenes in a polymerization process that involves the sequential or parallel polymerization of propylene homopolymer and copolymer using propylene with a small amount of comonomer, preferably ethylene. The polymerization is catalyzed by a dual metallocene catalyst system. The resulting polymers have a broad, bimodal molecular weight distribution. The resulting polymers are excellent for use in the production of biaxially oriented films or non-oriented films. Films prepared with these propylene polymers have a significantly broader processability range and can be evenly stretched at lower temperature compared to films prepared from traditional propylene polymer.
摘要:
Catalyst systems and methods for supporting catalysts and their components, particularly metallocene catalyst components, are provided. The method involves techniques for evenly distributing a small volume of catalyst component over and among a porous support material. Such even distribution is thought to result in reduced fouling.
摘要:
This invention relates to improved polypropylene nonwoven fabrics. The fabrics are made from isotactic polypropylene which has been produced with a catalyst systems comprising at least two metallocenes. These nonwoven fabrics, particularly when prepared using a spunbonding process, exhibit significantly improved strength without significant sacrifice of other favorable properties.
摘要:
This invention relates to supported metallocene catalyst systems and to methods for their production and use. Specifically, this invention relates to supported catalyst systems having unique, predetermined properties resulting from the designed distribution of catalyst components within and upon porous support particles. The designed distribution of catalyst components is obtained through sequential deposition of catalyst components with intervening removal of solvent.
摘要:
This invention relates to a catalyst support comprising the result of the combination of: (a) a support comprising hydroxyl groups; (b) a capping agent comprising a boron containing Lewis acid; and (c) an ionic activator, wherein at least some of the capping agent does not form a support bound activator.
摘要:
This invention relates to metallocene catalyst compositions which are highly active for the polymerization of olefins, particularly prochiral &agr;-olefins. The catalyst compositions contain at least one metallocene, and least one activator and a support that has been fluorided using a fluoride containing compound.
摘要:
This invention relates to metallocene catalyst compositions which are highly active for the polymerization of olefins, particularly prochiral &agr;-olefins. The catalyst compositions contain at least one metallocene, and least one activator and a support that has been fluorided using a fluoride containing compound.
摘要:
This invention is generally directed toward a supported catalyst system useful for polymerizing olefins. The method for preparing the catalyst system of the invention provides for an optionally supported, metallocene catalyst component which when utilized in a polymerization process exhibits improved reactor operability.
摘要:
An intermetallic compound comprising the reaction product of a transition metal and a reducing metal of a higher oxidation potential than the transition metal obtained by the reaction of a polymeric transition metal oxide alkoxide and the reducing metal in the presence of dicarbonyl compound; and catalyst components and systems for the polymerization of alpha olefins.