Hyosung Corporation

Ik-Hyun Kwon

Soo-Myung Choi

Jae-Shik Choi

Tae-Jung Lee

Young-Gyo Choi

Seok-Jong Han

Young-Soo Wang

Sung-Ryong Kim

Yang-Ho Chenon

Hyun-Soo Kim

Si-Hwan Joo

Yun-Hyuk Bang

Jong-Cheul Ji

Chan-Min Park

Young-Jo Kim

Woo-Sung Kim

Byung-Jun Song

Jong-Bok Lee

Kyoun-Ho Kim

Il-Won Jung

Young-Go Choi

High-purity 2,6-dimethylnaphthalene is prepared by (1) subjecting a dimethylnaphthalene isomer mixture rich in 1,5-dimethylnaphthalene, high boiling point materials, unreacted 1,5-dimethyltetralin, and low boiling point materials, which are produced from a dehydrogenation reaction of 1,5-dimethyltetralin, to separation, using a distillation column; subjecting the dimethylnaphthalene mixture separated by the distillation column to liquid state isomerization in the presence of an isomerization catalyst; (3) a first crystallization (melt crystallization process) by cooling the product of liquid state isomerization with a refrigerant without a solvent to form crystals; and (4) a second crystallization (solution crystallization process) of mixing the crystals of the first crystallization step with a solvent to form crystals.

Method for obtaining 2,6-dimethylnaphthalene using isomerization and crystallization processes

The present invention relates to cellulose fiber containing 500 to 2000 of filaments and having homogeneous physical properties and the multi-filaments according to the present invention is characterized in that the strength and the breaking elongation of the multi-filaments are 4 to 9 g/d and 4 to 15%, respectively. In particular, the present invention is characterized in that each mono-filament selected 100 strands from every three part divided from multi-filaments has properties as following: (a) 3 to 9 g/d in average strength, 7 to 15% in average breaking elongation and 0.035 to 0.055 in by birefringence, (b) the differences of the above three parts are below 1.0 g/d in average strength, 1.5% in breaking elongation and 0.7 denier in denier, (c) the CV (%) (coefficient of variation) of the above three parts are below 10%, and (d) the birefringence differences of the above three parts are below 0.004.

Cellulose multi-filament

Disclosed herein is a process of producing high purity and high yield dimethylnaphthalene by dehydrogenating a dimethyltetralin isomer using a metal catalyst for dehydrogenation. The metal catalyst contains a carrier selected from alumina (AlO), silica (SiO), a silica-alumina mixture and zeolite. The metal catalyst also contains 0.05 to 2.5% by weight of platinum (Pt), 0.1 to 3.0% by weight of tin (Sn) or indium (In), 0.5 to 15.0% by weight of at least one selected from the group consisting of potassium (K), magnesium (Mg) and cesium (Cs), 0.3 to 3.0% by weight of chlorine, and 0.01 to 3.0 % by weight of zinc (Zn) or gallium (Ga) as active components based on an element weight of the final catalyst.

Dehydrogenation process of dimethylnaphthalene using metal catalyst

Cellulose fiber for using as industrial materials

Disclosed is a 3-D crimp polyethylene terephthalate multifilament (BCF) having a stress-strain curve that (a) it elongates less than 5.0% when subjected to an initial stress of 1.0 g/d, (b) it has an initial modulus of 20 to 60 g/d, (c) it elongates at least 20% when subjected to a stress region of 1.0 to 2.5 g/d and (d) it elongates from a tensile strength of at least 3.0 g/d to the tensile strength at break. The BCF has improved physical properties such as excellent flame retardancy, high toughness, improved crimp uniformity and improved compressive elasticity modulus.

3-Dimension crimp polyethylene terephthalate multifilament for carpet

An apparatus and a method for effectively recovering acetic acid and catalyst from a mother liquor discharged from a series of processes including an oxidation process, a crystallization process and a solid-liquid separation process, in a continuous process for preparing naphthalenedicarboxylic acid by oxidizing dimethylnaphthalene in the presence of an oxygen-containing gas and an acetic acid solvent, using a catalyst system comprising a transition metal such as cobalt or manganese, and a bromine-based compound, are provided.

Apparatus and method for recovering acetic acid and catalyst in process for preparation of 2,6-naphthalenedicarboxylic acid

It is an object of the present invention to provide a hybrid dip cord consisting of rayon yarn and lyocell yarn to apply to the carcass ply or cap ply (belt reinforced layer) of pneumatic radial tire used in a car and a radial tire using the same. And also, according to the present invent the hybrid dip cord and the radial tire for application to the carcass ply or cap ply (belt reinforced layer) of pneumatic radial tire used in cars are produced by means of the following steps; imparting S direction twist of 20 to 200 TPM yarn number to one rayon yarn to produce a pre-yarn, imparting twist to said one rayon pre-yarn and one non-twisted lyocell respectively to produce a ply twist yarn, and imparting cable twist to two ply of ply twist yarn made from combination of said ply twist yarn or impart cable twist to a ply twist yarn to be produced by regulating low the twist number of one lyocell yarn and the rayon yarn to one lyocell as 20 to 200 TPM when the ply twist processes.

Dipped cord using hybrid cord and a radial tire using the same

The present invention relates to, and more particularily, to a lyocell dip cord and tire produced by a method comprising the steps of: (A) dissolving 0.01 to 3 wt % of cellulose powder in portions in concentrated liquid N-methylmorpholine N-oxide (NMMO) to prepare cellulose-containing NMMO solution; (B) feeding the NMMO solution and cellulose powder into an extruder having a screw to be subjected to dispersing, mixing, shearing, kneading, melting and measuring ability in the extruder to prepare a swollen and homogenized cellulose solution; (C) spinning the cellulose solution through a spinning nozzle, passing the spinning solution through an air gap to a coagulation bath and coagulating the spinning solution to obtain a multifilament; (D) subject the multifilament to water-wash, drying and oil-treatment, followed by winding; and (E) twisting the wound yarn with a twisting machine to prepare a greige cord, weaving the greige cord and dipping the woven cord in a dipping solution.

Cellulose dip cord produced from highly homogeneous cellulose solution and tire using the same

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Kyonggi-do, South Korea

Ik-Hyun Kwon