Abstract: Provided are a method for preparing a polyetherketoneketone and a polyetherketoneketone prepared thereby, wherein, at the time of a polymerization reaction, nitrogen gas is blown into a liquid reaction medium while stirring, thereby quickly removing hydrochloric acid, which is a by-product generated during the reaction, and preventing aggregation of resin particles, thus suppressing the generation of scales.

Abstract: The present invention relates to a catalyst for hydrogenation of an aromatic compound, which is capable of greatly reducing the inactivation of a catalyst by using a support including a magnesium-based spinel structure, and a preparation method therefor.

Abstract: A polysilicon manufacturing apparatus according to an exemplary embodiment of the present invention includes: a reactor in which a reactive gas is introduced to perform a polysilicon manufacturing process by a chemical vapor deposition (CVD) method; and a slit-type nozzle installed at the reactor and spraying a gas inside the reactor to prevent absorption of silicon particles during a process.

Abstract: The present invention relates to a method for producing a polyamide by coordinated anionic ring-opening polymerization and a polyamide produced thereby, wherein metal alkoxide as an initiator and metal hydride as a catalyst are added to enable polymerization having a narrow molecular weight distribution and uniform molecular weight within a short polymerization reaction time at a low temperature, without a separate vacuum process, as compared with an existing polymerization method.

Abstract: The present invention provides a method for producing a polyamide with controlled activator addition, and a polyamide produced thereby, the method allowing a polymerization conversion rate and a polydispersity index (PDI) to be enhanced by controlling the addition of an activator so as to prevent a gelation phenomenon that occurs during anionic polymerization.

Abstract: Provided is a method for preparing a polyamide by an anionic polymerization reaction, wherein lactam, and based on 100 parts by weight of the entire lactam, 0.01 parts by weight to 20 parts by weight of an alkali metal as an initiator, 0.3 parts by weight to 10 parts by weight of a molecular weight controller, and 0.002 parts by weight to 1.0 part by weight of carbon dioxide as an activator may be included.

Abstract: The present invention relates to a high-density ethylene-based polymer and a pipe using the same, the high-density ethylene-based polymer including: an ethylene homopolymer; or a copolymer of ethylene and at least one comonomer selected from the group consisting of an ?-olefin, a cyclic olefin and linear, branched and cyclic dienes. The pipe using the high-density ethylene-based polymer of the present invention has more superior strain hardening than a conventional polyethylene resin pipe, and thus has excellent long-term pressure resistance characteristics and processability.

Abstract: Provided is a method capable of preparing high-purity aliphatic isocyanate, particularly, xylylene isocyanate in a high yield in a simple manner without an additional separate process, wherein when aliphatic isocyanate is prepared using phosgene, a side-reaction inhibitor capable of inhibiting side-reactions is introduced during phosgenation.

Abstract: A preparation method for a metallocene compound is provided. The method includes: stirring at least one compound I among compounds expressed by the following chemical formula (I) and a hydrogenation reaction catalyst of 0.10 to 0.55 parts by weight based on 100 parts by weight of the compound I under a hydrogen atmosphere; and obtaining a metallocene compound containing at least one first compound among the compounds expressed by the following chemical formula (1). Chemical formula (I) and (1) are provided in the specification.

Abstract: Provided is a method capable of preparing high-purity aliphatic isocyanate, particularly, xylylene isocyanate in a high yield in a simple manner without an additional separate process, wherein when aliphatic isocyanate is prepared using phosgene, a side-reaction inhibitor capable of inhibiting side-reactions is introduced during phosgenation.

Abstract: The present invention relates to a method for producing a vinyl chloride-based resin composition which exhibits good processability due to excellent solubility in a solvent, can implement excellent transparency in products produced, and improves the glossiness of a coating film when used as an ink binder, thereby being capable of being used as a high-quality adhesive and ink binder, and a method for producing the same.

Abstract: The present invention relates to a gas distribution unit for a fluidized bed reactor system, a fluidized bed reactor system having the gas distribution unit, and a method for preparing granular polysilicon using the fluidized bed reactor system. The gas distribution unit for a fluidized bed reactor system according to the present invention enables gas flow rate control and gas composition control for each zone within the plenum chamber. In addition, a fluidized bed reactor system having the gas distribution unit enables shape control of a fluidized bed (in particular, transition between a bubbling fluidized bed and a spout fluidized bed). The method for preparing granular polysilicon using the fluidized bed reactor system not only simultaneously improves process stability and productivity, but also enables more flexible handling in the event of an abnormal situation.

Abstract: The present invention relates to a hybrid supported metallocene catalyst including at least first metallocene compound, at least one second metallocene compound, at least one cocatalyst compound, and a carrier, a preparation method therefor, and a polyolefin resin polymerized in the presence of the catalyst, wherein the second metallocene compound is a compound of a bridged structure having a ligand of an asymmetric structure, and the polyolefin resin has a density of 0.910 g/cm3 to 0.960 g/cm3, a molecular weight density in a unimodal distribution of 3 to 5, a melt index of 0.05 to 100 at 2.16 kg, and a melt flow rate of 20 to 40.

Abstract: The present invention relates to a novel Group 4 transition metal compound, a method for preparing the compound, a catalyst composition comprising the compound, and a method for preparing a polyolefin comprising performing a polymerization reaction of olefin monomers, in the presence of the catalyst composition. Since the Group 4 transition metal compound of the present invention exhibits an excellent catalytic activity in polyolefin synthesis reactions, as well as having excellent thermal stability, it can be used for polyolefin synthesis reactions at high temperatures, and by changing the type of a central metal and ligand, the weight average molecular weight of synthesized polyolefins and the octene content in the polymer can be controlled. Therefore, it can be effectively used in polyolefin synthesis processes in which grades are controlled.

Abstract: The present invention relates to a novel Group 4 transition metal compound, a method for preparing the compound, a catalyst composition comprising the compound, and a method for preparing a polyolefin comprising performing a polymerization reaction of olefin monomers, in the presence of the catalyst composition. Since the Group 4 transition metal compound of the present invention exhibits an excellent catalytic activity in polyolefin synthesis reactions, as well as having excellent thermal stability, it can be used for polyolefin synthesis reactions at high temperatures, and by changing the type of a central metal and ligand, the weight average molecular weight of synthesized polyolefins and the octene content in the polymer can be controlled. Therefore, it can be effectively used in polyolefin synthesis processes in which grades are controlled.

Abstract: A high-density ethylene-based polymer is provided. The high-density ethylene-based polymer contains an ethylene homopolymer or a copolymer of ethylene and at least one comonomer selected from the group consisting of an ?-olefin, a cyclic olefin, and a straight, branched and cyclic diene. The high-density polyethylene resin has a wide molecular weight distribution and excellent comonomer distribution characteristics, has excellent melt flowability due to a long chain branched structure, and has excellent mechanical characteristics since the comonomer distribution is concentrated in a high-molecular-weight body. The high-density ethylene polymer has excellent molding processability during processing such as extrusion, compression, injection and rotational molding by having excellent mechanical characteristics and melt flowability.

Abstract: The present invention relates to a high-density ethylene-based polymer comprising an ethylene homopolymer or a copolymer of ethylene and at least one comonomer selected from the group consisting of an ?-olefin, a cyclic olefin, and a straight, branched and cyclic diene. According to the present invention, the high-density polyethylene resin has a wide molecular weight distribution and excellent comonomer distribution characteristics, has excellent melt flowability due to a long chain branched structure, and has excellent mechanical characteristics since the comonomer distribution is concentrated in a high-molecular-weight body. The high-density ethylene polymer of the present invention has excellent molding processability during processing such as extrusion, compression, injection and rotational molding by having excellent mechanical characteristics and melt flowability.

Abstract: Provided is a polysilicon manufacturing apparatus including a reactor disposed on a base plate to form a reaction chamber, a pair of electrical feedthroughs installed on the base plate to be extended to the inside of the reaction chamber, rod filaments installed on the electrical feedthroughs in the reaction chamber and connected to each other by a rod bridge at the upper end to form a silicon rod by chemical vapor deposition of source gas introduced to a gas inlet, and a cooling jacket inserted to a through-hole provided at the upper side of the reactor to be supported to the base plate, connected to a gas outlet formed on the base plate by forming a gas passage discharging the gas after reaction, and introducing and circulating a low-temperature coolant to a coolant passage from the outside of the reactor by forming the coolant passage at the outside of the gas passage to discharge a high-temperature coolant to the outside of the reactor.

Abstract: The present invention relates to a high-density ethylene-based polymer comprising: an ethylene homopolymer; or a copolymer of ethylene and at least one comonomer selected from the group consisting of ?-olefins, cyclic olefins and linear, branched and cyclic dienes. According to the present invention, the high-density ethylene-based polymer has a wide molecular weight distribution and excellent comonomer distribution characteristics, has excellent melt flowability due to a long chain branched structure, and has excellent mechanical characteristics since the comonomer distribution is concentrated in a high-molecular-weight body. The high-density ethylene polymer of the present invention has excellent molding processability during processing such as extrusion, compression, injection and rotational molding by having excellent mechanical characteristics and melt flowability.

Abstract: The present invention relates to a polyvinyl chloride (PVC)-based compound composition, and more specifically, to a PVC-based compound composition that uses a PVC-based copolymer having internal plasticity prepared by suspension polymerization together with a PVC resin, thereby increasing compatibility with the PVC resin to shorten the gelling time, lowering the load at the time of extrusion to increase production in the same process conditions, and partially showing an impact modifier substitution effect.