477 results about "Ziegler–Natta catalyst" patented technology

A process for producing high density polyethylene in the presence of a Ziegler-Natta catalyst system in two liquid full loop reactors in series, wherein in a first reactor a first polyethylene product is polymerized substantially by homopolymerization of ethylene and hydrogen, optionally with a minor degree of copolymerization of ethylene with an alpha-olefinic comonomer comprising from 3 to 8 carbon atoms, and in a second reactor serially connected to the first reactor downstream thereof a second polyethylene product is copolymerized from ethylene and an alpha-olefinic comonomer comprising from 3 to 8 carbon atoms, and a hydrogenation catalyst is introduced into the reactants downstream of the first reactor.

The instant disclosure is directed to a thermoplastic vulcanizate composition comprising a dynamically-cured rubber; from about 20 to about 300 parts by weight of a thermoplastic resin per 100 parts by weight rubber and from about 30 to about 250 parts by weight additional oil per 100 parts by weight rubber; wherein the rubber comprises a multimodal polymer composition cured with a curing agent, the multimodal polymer composition comprising 45 to 75 wt% of a first polymer fraction and 25 to 55 wt % of a second polymer fraction, each comprising ethylene, a C₃-C₁₀ alpha-olefin, and a non-conjugated diene, wherein the polymer fractions have been polymerized using a Ziegler-Natta catalyst system, wherein the first polymer fraction has a Mooney viscosity of greater than or equal to about 150 ML(1+4@125° C.), and the second polymer fraction has a Mooney viscosity of about 20 ML to about 120 ML; and about 10 phr to about 50 phr of an extender oil. A method of producing the thermoplastic vulcanizate is also disclosed.

A Ziegler-Natta catalyst composition comprising a solid mixture formed by halogenation of: Al) a spray-dried catalyst precursor comprising the reaction product of a magnesium compound, a non-metallocene titanium compound, and at least one non-metallocene compound of a transition metal other than titanium, with A2) an organoaluminium halide halogenating agent, a method of preparing, precursors for use therein, and olefin polymerization processes using the same.

The present invention relates to propylene polymerization process in a bulk loop reactor, and particularly to propylene polymerization process for polymerizing commercial quantities of polypropylene in a bulk loop reactor by sequentially introducing Ziegler-Natta and metallocene catalyst systems into the bulk loop reactor. In one embodiment, separate catalyst mixing systems are used to introduce a quantity of metallocene catalyst and Ziegler-Natta catalyst into the bulk loop reactor. The frequency rate at which the quantity of metallocene catalyst is introduced into the bulk loop reactor may be higher than the frequency rate at which the quantity of Ziegler-Natta catalyst is introduced. In another embodiment, a method of polymerizing propylene in a bulk loop reactor is provided which includes contacting a quantity of supported metallocene catalyst with a first quantity of scavenger, such as TEAL and or TIBAL, prior to injecting the supported metallocene catalyst into the bulk loop reactor and contacting a quantity of Ziegler-Natta catalyst system with a second quantity of scavenger prior to injecting the Ziegler-Natta catalyst system into the bulk loop reactor, wherein the second quantity of scavenger is greater that the first quantity of scavenger. In another embodiment, a method of contacting a flow of metallocene with a flow of propylene is provided. This method includes directing the flow of metallocene towards a junction, directing the flow of propylene towards the junction and maintaining a portion of the flow of metallocene separate from a portion of the flow propylene within a portion of the junction downstream of the flow of propylene into the junction. In another embodiment, a method of introducing a quantity of antifouling agent into a catalyst mixing system is provided. In this embodiment a portion of the antifouling agent is introduced at or downstream of a point of contact of a stream of propylene with a stream of catalyst. The antifouling agent may be a member, alone or in combination with other members, selected from the group consisting of Stadis 450 Conductivity Improver, Synperonic antifouling agent, and Pluronic antifouling agent.

This invention relates to processes for transitioning among polymerization catalyst systems, preferably catalyst systems, which are incompatible with each other. Particularly, the invention relates to processes for transitioning among olefin polymerization reactions utilizing Ziegler-Natta catalyst systems, metallocene catalyst systems and chromium-based catalyst systems.

The present invention relates to a process for producing polypropylene terpolymer composition by polymerizing propylene with ethylene and C4 to C8 α-olefin monomers in a sequential polymerization process with at least two reactors connected in series in the presence of solid Ziegler-Natta catalyst having a surface area below 20 m²/g.

The invention relates to polypropylene with narrow distribution of molecular weight and a preparation method, and especially relates to a propylene polymer with narrow distribution of molecular weight by employing a Ziegler-Natta catalyst through direct reactor polymerization. The polymer has high and adjustable isotacticity, the molecular weight distribution is narrow, and the high-molecular trailing index is high. propylene is not contained in a locational isomeric structure, the melting point and crystallization temperature are high, compared with a traditional degradation method for producing the polypropylene with narrow distribution, the polypropylene with narrow distribution of molecular weight has the advantages of economy, energy saving and environmental protection. The product is especially suitable for the fields with high fluidity requirement such as spinning, injecting by a thin wall, casting the transparent material. In addition, due to characteristic of narrow distribution of molecular weight, the polymer has a certain advantage on transparency application aspect.

A process for preparing a Ziegler-Natta catalyst used for the sludge polymerization of ethene features that in its preparing procedure the ultrasonic wave technique is used for increasing the content of Ti and improving the granularity distribution of polymer.

The present invention is a high barrier multilayer film particularly suitable for packaging. The high barrier multilayer film is a film including (a) a core substrate layer having an isotactic polypropylene produced from Ziegler-Natta catalysts, and (b) an adjacent layer on at least one surface of the core substrate layer, wherein the adjacent layer (b) comprises an isotactic polypropylene produced from metallocene catalysts; or the high barrier multilayer film includes (a') a core substrate layer having an isotactic polypropylene produced from metallocene catalysts, and (b') an adjacent layer on at east one surface of the core substrate layer, wherein the adjacent layer (b') comprises an isotactic polypropylene produced from Ziegler-Natta catalysts.

The invention discloses a high-rubber polypropylene polyphase copolymer resin used for 3D printing, and a preparation method and an application thereof. The copolymer resin is composed of a propylene homopolymer and crosslinked ethylene-propylene-diolefin diolefin copolymer rubber, and is prepared through sequentially catalyzing propylene monomer homopolymerization and ethylene/propylene/diolefin monomer copolymerization by a catalyst containing a carrier type Ziegler-Natta catalyst. The content of rubber in the copolymer resin reaches above 70%, the obtained polymer product is particles with the particle diameter of 50-1500mum, and a heat stabilizer is added to make the resin form an high-impact-resistance and high-toughness product through 3D printing molding.