Process for the production of a polypropylene based article having improved surface tension retention, and polypropylene based article having improved surface tension

Provided are a novel metallocene-supported catalyst and a method of preparing a polyolefin using the same. The metallocene-supported catalyst according to the present disclosure may be used in the preparation of polyolefins, it may have excellent activity and excellent reactivity with comonomers, and it may prepare olefinic polymers having a high molecular weight and a low molecular weight.

The invention relates to a new soft heterophasic propylene copolymer with increased melting temperature, improved stiffness and optical properties, as well as the process by which the heterophasic propylene copolymer is produced. Further the present invention is directed to articles made of the inventive heterophasic propylene copolymer, particularly to blow moulded, extrusion blow moulded or injection moulded articles and their use in e.g. medical, pharmaceutical or alimentary applications.

A metal complex of the formula (1) TCyLMZ.sub.p (1), wherein M is a group 4 metal, Z is an anionic ligand, p is the number 1 or 2, TCy is a thiophene-fused cyclopentadienyl-type ligand of the formula (2)

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is described. Methods of making and using the metal complex are also described.

The present invention relates to a method for evaluating an injection physical property of a plastic resin, and a polyethylene resin suitable for an injection molding process and, more particularly, to a novel method for evaluating an injection physical property of a plastic resin, which, when a particular plastic resin is processed by an injection process, can accurately derive injection suitability of the plastic resin and injection pressure in the injection process through a physical property value measured by using a resin specimen, and a polyethylene resin suitable for injection molding.

A metallocene catalyst compound can comprise a structure represented by formula (F-MC) below comprising a first cyclopentadienyl ring with carbon atoms directly connected with R.sup.1, R.sup.2, R.sup.4, and R.sup.5, and a second cyclopentadienyl ring with carbon atoms directly connected with R.sup.10, R.sup.11, R.sup.12, and R.sup.13, and a bridging group (BG) directly connecting the first and second cyclopentadienyl rings

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A catalyst system can include the metallocene compound, a non-coordinating anion type activator comprising a supported alumoxane or aluminum alkyl, and optionally a scavenger. A process for making a polymeric product can comprise: contacting a C.sub.2-C.sub.22 alpha-olefin feed with the catalyst system to obtain a polymerization reaction mixture; and obtaining a polymer product from the polymerization reaction mixture. A polymer product can be made by the process to exhibit at least an Mn from 7,000 g/mol to 70,000 g/mol and a PDI from 4.1 to 9.0.

The present disclosure relates to a method for preparing a polyolefin using a supported hybrid metallocene catalyst. According to the present disclosure, a polyolefin having a narrow molecular weight distribution can be prepared very effectively by introducing a cocatalyst in an optimum conent in the presence of a supported hybrid metallocene catalyst containing two or more metallocene compounds having a specific chemical structure. The polyolefin prepared according to the present disclosure exhibits excellent uniformity in chlorine distribution in polyolefin during chlorination, thereby significantly improving elongation of the chlorinated polyolefin, compatibility with PVC and impact reinforcing performance. Thus, it exhibits excellent chemical resistance, weather resistance, flame retardancy, processability and impact strength reinforcing effect, and can be suitably applied as an impact reinforcing agent for PVC pipes and window profiles.

A polyethylene according to the present disclosure maintains a stable crystal structure at a high temperature and ensures excellent uniformity in chlorine distribution, thereby preparing a chlorinated polyethylene having excellent chlorination productivity and thermal stability by reacting with chlorine, and may also prepare a PVC compound with improved impact strength by including the chlorinated polyethylene.

The present disclosure provides a supported catalyst system and process for use thereof. In particular, the catalyst system includes an unbridged metallocene compound, an additional unbridged metallocene compound having a structure different than the first unbridged metallocene compound, a support material and an activator. The catalyst system may be used for preparing polyolefins.

A catalyst composition, a method from preparing an olefin polymer using the same, and an olefin polymer prepared from the same are disclosed herein. In some embodiments, a catalyst composition includes a first metallocene compound represented by the Chemical Formula 1, a second metallocene compound represented by the Chemical Formula 2, and a support. The catalyst composition can exhibit high activity in an olefin polymerization reaction and thus contribute to reducing catalyst costs, and can also exhibit high copolymerizability which can secure excellent processability and long-term physical properties, and thus, is suitable for providing polymers for pipes.