Abstract: The present invention relates to a method for optimizing the sequential use of at least two ethylene polymerization catalysts to an ethylene polymerization loop reactor, comprising: transferring to a mixing vessel a first ethylene polymerization catalyst and a first diluent, thereby providing a first catalyst slurry, transferring said first catalyst slurry from said mixing vessel to an ethylene polymerization loop reactor at a concentration suitable for polymerizing ethylene, increasing the ratio of said diluent to said first ethylene polymerization catalyst in said first catalyst slurry, stopping the supply of said first catalyst slurry to said mixing vessel, stopping the supply of said first catalyst slurry to said ethylene polymerization loop reactor, stopping the supply of ethylene to said ethylene polymerization loop reactor, removing said first catalyst slurry from said ethylene polymerization loop reactor, emptying said mixing vessel, optionally rinsing said mixing vessel with fresh diluent, transfe
Abstract: The present invention relates to a process for the production of fibres and filaments with polypropylene having a broad polydispersity index. The present invention also relates to high elongation nonwoven prepared from such fibres and filaments. It further relates to films and laminates prepared from high elongation nonwoven.
Abstract: An apparatus defined as a set of loop reactors suitable for the polymerization process of a monomer, preferably ethylene and optionally an olefin co-monomer, comprising for each of said reactors: a plurality of interconnected pipes P defining a flow path for a polymer slurry, said slurry consisting essentially of ethylene, optionally a co-monomer, a polymerization catalyst, liquid diluent and solid olefin polymer particles, means for feeding monomer, optionally a co-monomer, diluent and optionally hydrogen in the reactor, means for feeding a polymerization catalyst in the reactor, a pump suitable for maintaining the polymer slurry in circulation in such reactor, one or more settling legs connected to the pipes P of such reactor for settling of polymer slurry, one or more control valves connected to the outlet of such settling legs, and one or more flash lines for discharging settled polymer slurry out of the reactor characterized in that each of said loop reactors comprises a three-or-more-way valve defini
Abstract: A resin composition comprising at least 0.1% by weight of poly(hydroxy carboxylic acid) and at least 50% by weight of polar low density polyethylene, the pLDPE comprising from 0.5 to 25% by weight of a polar vinyl-containing comonomer.
Abstract: The present invention concerns heterophasic propylene copolymers, comprising a propylene homopolymer (PPH) and an ethylene-propylene rubber (EPR), having a broad molecular weight distribution and a well-defined total ethylene content and a specific ratio of the intrinsic viscosities of the ethylene-propylene rubber (EPR) and the propylene homopolymer (PPH), ?EPR/?PPH. The invention further concerns the process to produce such heterophasic propylene copolymers. The heterophasic propylene copolymers of the present invention are particularly suited for corrugated sheet and cast film applications.
Abstract: The present invention discloses a homo- or co-polymer of ethylene characterised in that it combines the properties of: a) melt strength MS?0.021 p-0.131 wherein melt strength MS is expressed in N and extruder head pressure p is expressed in MPa, when processed in a rheological extruder through a die with L/D of 30:2 at a rate of 500 s?1 and at temperature of 190° C.; b) long chain branching index g? determined by SEC-VISCO larger than 0.90; c) polydispersity index (Mw/Mn) of at most 7. It also discloses a method to prepare said polyethylene resin.
March 4, 2008
Date of Patent:
November 20, 2012
Total Petrochemicals Research Feluy
Jacques Michel, Marc Dupire, Prades Floran
Abstract: The present invention discloses a catalyst system that comprises several bridged pseudo-bisindenyl components that are structurally different in order to prepare polymers having a broad molecular weight distribution.
Abstract: A polyethylene resin having a multimodal molecular weight distribution comprising at least two polyethylene fractions A and B, fraction A being substantially free of comonomer and having a lower weight average molecular weight and a higher density than fraction B, each fraction prepared in different reactors of two reactors connected in series in the presence of a Ziegler-Natta catalyst system, the polyethylene resin having a density of from 0.950 to 0.965 g/cm3 and a melt index MI2 of from 0.5 to 5 g/10 min.
November 3, 2010
November 8, 2012
TOTAL PETROCHEMICALS RESEARCH FELUY
Jean-Marie Boissiere, Aurélien Vantomme, Pierre Belloir, Alain Van Sinoy
Abstract: The present invention relates to a process for cleaning a catalyst slurry preparation system and/or a catalyst preparation system. More particularly, the invention relates to a cleaning process for a catalyst preparation system and/or for a catalyst slurry preparation system, wherein an aqueous catalyst inactivation agent is used to rinse the systems, or any parts thereof. The catalysts used in the present invention may be chromium, Ziegler-Natta or metallocene catalysts.
Abstract: Use of a metallocene compound of general formula Ind2R?MQ2 as a component of a catalyst system in producing polyethylene, wherein each Ind is the same or different and is indenyl or substituted indenyl; R? is a bridge which comprises a C1 to C4 alkylene radical, a dialkyl germanium or silicon or siloxane, alkyl phosphine or amine, which bridge is substituted or unsubstituted, M is a Group IV metal or vanadium and each Q is hydrocarbyl having 1 to 20 carbon atoms or halogen; and the ratio of meso to racemic forms of the metallocene in the catalyst system is at least 1:3. The metallocene may be supported. The ethylene may be polymerized in a reaction medium that is substantially free of any external comonomer, with comonomer being formed in situ. The produced polyethylene may have long chain branching. The produced polyethylene may be atactic.
Abstract: The invention relates to a process for the preparation of a particulate polyethylene product in a loop reactor, wherein the polymerization catalyst applied in the polymerization process comprises a particulate metallocene-alumoxane catalyst immobilized on a porous silica support; and whereby said metallocene-alumoxane catalyst is heterogeneously distributed on said porous silica support.
Abstract: The present invention relates to a method for producing a catalyst slurry blend suitable for polymerizing ethylene in an ethylene polymerization loop reactor for obtaining an at least trimodal polyethylene product, comprising the steps of: transferring a first ethylene polymerization catalyst at a first mass flow rate to a mixing vessel, simultaneously transferring a second ethylene polymerization catalyst at a second mass flow rate to said mixing vessel, thereby in situ providing a catalyst slurry blend, wherein said second ethylene polymerization catalyst is different from the first ethylene polymerization catalyst, adjusting and monitoring said first and second mass flow rates, thereby obtaining said catalyst slurry blend at a concentration suitable for polymerizing ethylene, and feeding said catalyst slurry blend to an ethylene polymerization double loop reactor producing said at least trimodal polyethylene product.
Abstract: The present invention relates to a method for initiating an ethylene polymerization reaction in an ethylene polymerization loop reactor. More particularly, the invention relates to the timing upon which hydrogen is introduced into the ethylene polymerization loop reactor. The catalysts used in the ethylene polymerization reaction according to present invention are preferably metallocene catalysts.
Abstract: A homogenous blend comprising from 10% to 90% by weight of a metallocene catalyzed polyethylene (mPE) and from 90% to 10% by weight of styrene-butadiene block copolymers comprising from 5% to 40% by weight of 1,3 butadiene monomer units and from 60% to 95% by weight of styrene monomer unites. The blend of the invention is used to make peelable films for food packaging applications.
Abstract: The present invention relates to a process for the production of fibers and filaments with polypropylene having a broad polydispersity index. The present invention also relates to high elongation nonwoven prepared from such fibers and filaments. It further relates to films and laminates prepared from high elongation nonwoven.
Abstract: A resin composition comprising at least 0.1% by weight of poly(hydroxy carboxylic acid) and at least 50% by weight of polyethylene prepared with a single-site catalyst, preferably a metallocene.