Hyosung Corporation

Ik-Hyeon Kwon

Soo-Myung Choi

Jae-Shik Choi

Tae-Jung Lee

Seok-Jong Han

Sung-Ryong Kim

Young-Soo Wang

Myung-Woo Kim

In-Ho Lee

Jong Sung Lee

Jang-Won Lee

Kwang-Chul Hyun

Woo-Sik Jeong

Yong-Chul Park

Deuk-Jin Lee

Eung-Soo Kim

Yun-Hyuk Bang

Yang-Kuk Son

Seung-Cheol Yang

Woo-Sung Kim

Young-Jo Kim

Chan-Min Park

Disclosed herein are a process for the refinement of nitrogen trifluoride gas and an adsorbent used therein. A nitrogen trifluoride (NF3) gas including carbon tetrafluoride (CF4) as an impurity is permeated into a bed of the zeolite 3 A, 4A or 5 A which is ion exchanged with alkali earth metal and is thermally treated at 150 to 600&#xb0; C. for 0.5 to 100 hours so as to selectively adsorb nitrogen trifluoride onto the bed, followed by the desorption of the nitrogen trifluoride therefrom.

Process for refining nitrogen trifluoride gas using alkali earth metal exchanged zeolite

Disclosed herein are a process for the refinement of nitrogen trifluoride gas and an adsorbent therefor. A nitrogen trifluoride (NF3) gas including carbon tetrafluoride (CF4) as an impurity is permeated into a bed of zeolite 3A, 4A or 5A which undergoes ion exchange and impregnation with alkali earth metal and is thermally treated at 150 to 600&#xb0; C. for 0.5 to 100 hours so as to be able to selectively adsorb nitrogen trifluoride onto the bed, followed by the desorption of the nitrogen trifluoride therefrom.

Process for refining nitrogen trifluoride gas using alkali earth metal exchanged and impregnated zeolite

Disclosed is a flame-retardant polyester polymer dyeable with a cationic dye, a method of producing the same, a copolyester fiber using the same, and fiber products using the copolyester fiber. In the method, after a dimethyl isophthalate component containing metal sulfonate of Formula 2 separately reacts with ethylene glycol so that an extent of the ester interchange reaction is 95% or more to synthesize bis(hydroxyethyl terephthalate) containing metal sulfonate of Formula 3, bis(hydroxyethyl terephthalate) is fed so that a content of bis(hydroxyethyl terephthalate) is 0.01-5 mol % based on a diacid component in a polymer in a course of producing polyester, a phosphorus-based flame retardant of Formula 1 is fed so that a content of a phosphorus atom is 500-40000 ppm based on the polymer, and the mixture is copolymerized. The polyester polymer is dyeable with cationic dye while having excellent flame retardancy, and can be melt-spun like other polymers capable of being melt-spun. The copolyester fiber using the polyester polymer is capable of being processed according to processes through which conventional polyester fibers are processed, and is dyeable with cationic dye while having excellent flame retardancy.

Flame-retardant polyester polymer dyeable with cationic dye, method of producing the same, and copolyester fiber using the same

This invention relates to a method of preparing cellulose solution which is homogeneous at relatively low temperature, in which a small amount of cellulose powder or polyvinylalcohol is dissolved in the liquid-state, concentrated N-methylmorpholine-N-oxide (hereinafter, referred to as 'NMMO') so as to lower the solidifying temperature of NMMO, and then, the resulting solution and cellulose powder are fed into an extruder so as to be mixed, swollen and melted in the extruder.

Solution containing cellulose dissolved in N-methylmorpholine-N-oxide and high tenacity lyocell multifilament using the same

The present invention relates to a method for making highly homogenized cellulose solution, wherein the cellulose solution is obtained by obtaining a solidified N-methylmorphorine-N-oxide (hereinafter, referred to as 'NMMO') hydrates which is solidified a liquid-state NMMO hydrates comprising 10 to 18% by weight water by using a simple screw-type feeder and by controlling the temperature, feeding the solidified NMMO into a twin-screw type extruder continuously, obtaining a cellulose solution which is fully swelled in a few minutes by dispersing and mixing with cellulose powder in the twin-screw type extruder, and extruding a highly homogenized cellulose solution by feeding the obtained cellulose solution into a melting zone of the extruder to melting the cellulose solution in a few minutes by minimum heat and shear force.

Homogeneous cellulose solution and high tenacity lyocell multifilament using the same

The present invention relates to a high tenacity polyethylene naphthalate fiber containing a silica compound. This fiber is produced by a method comprising the steps of: (A) melt-spinning a solid phase-polymerized polyethylene-2,6-naphthalate chip containing ethylene-2,6-naphthalate units at more than 85 mole % and a silica compound and having an intrinsic viscosity of 0.70-1.20, to produce a melt-spun yarn; (B) passing the melt-spun yarn through a retarded cooling zone and a cooling zone to solidify the yarn; (C) withdrawing the yarn at such a speed that the undrawn yarn has a birefringence of 0.001-0.1; and (D) subjecting the undrawn yarn to multi-stage drawing at a total draw ratio of at least 1.5 and a drawing temperature of 50-250&#xb0; C. The polyethylene naphthalate fiber has improved physical properties, such as high tenacity, and a dipped cord produced from this fiber has excellent dimensional stability and tenacity such that it can be advantageously employed as a reinforcement material of rubber products.

High tenacity polyethylene-2, 6-naphthalate fibers having excellent processability

The present invention relates to a high tenacity, high modulus and low shrinkage lyocell multifilament yarn suitable for use in tire cords and MRG (mechanical rubber goods). The lyocell multifilament yarn is a cellulose-based fiber for industrial applications, which is produced by dissolving pulp having a degree of polymerization (DP) of 700-2,000 and preferably 800-1,400, and a &#x3b1;-cellulose content of more than 90% and preferably more than 92%, in N-methylmorpholine N-oxide (NMMO) hydrate, at a pulp concentration of 5-15% by weight and preferably 8-13% by weight. The lyocell monofilament according to the present invention is characterized by the following stress-strain profile: (1) the lyocell monofilament analyzed after drying is elongated by less than 3.0% and has an initial modulus of 150-400 g/d, when it was subjected to an initial stress of 3.0 g/d; (2) it is elongated by 3.0-7.0% when it was subjected to a stress greater than the initial stress but smaller than 6.0 g/d; and (3) it is elongated from a tensile tenacity of at least 6.0 g/d until the yarn is broken.

Lyocell multifilament

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Seoul, South Korea

Ik-Hyeon Kwon