• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2008.04a
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• pp.108-110
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• 2008

본 연구에서는 균일한 난연성능을 지닌 산업용 난연시트 제조 기술 개발을 목적으로, 제조공정 제어와 함께 친환경 난연제를 개발하였다. 기존 난연시트 제조과정에 산발적으로 나타나는 낮은 방염성능이 기모공정에 원인이 있음을 알고 기모촉진제 및 기모에 의한 물리적 화학적 결합력의 변화에 대하여 조사하였다. 그 결과 기모촉진제화 난연제간 혼화성은 문제가 없지만 기모촉진제 처리 후 시료표면의 소수성과 기모에 의한 물리적 구조의 변화가 난연제의 흡착을 방해함을 알 수 있었다. 따라서 기모공정과 난연공정 사이에 수세공정 첨가의 영향, 난연공정 온도변화의 영향, 그리고 염색과 동욕에서 난연제를 처리하는 방법으로 제조공정을 변화하여 균일한 난연성능 구현의 가능성을 조사하였다.

• Journal of Adhesion and Interface
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• v.11 no.1
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• pp.3-8
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• 2010

Thermal properties, flame retardant property, and sound-damping properties of polyurethane (PU) nanocomposite foams prepared with oligomeric 1,2-propanediol isobutyl polyhedral silsesquioxane (POSS) were investigated. It was found that the PU nanocomposite foams showed good sound-damping performances comparing to the PU foams without POSS.

• Journal of the Korean institute of surface engineering
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• v.35 no.3
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• pp.113-120
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• 2002

Injection molded plastic parts have many surface defects. These include a weld line, sink mark, flow mark, gloss, shading, scratching etc. Because these surface faults are not aesthetically acceptable, plastic parts are produced through painting or texturing. The purpose of this paper is to develop paintless molded parts using a flow control method. Computer aided injection mold filling simulations were used in order to minimize the number of defects from injection molding. Based on the numerical results, FR(Flame Retardant) HIPS was developed and the guidelines for part design, mold design, and the processing conditions were established. The effects of cost savings, improvements in productivity, and recycling were considered by reducing the number of surface faults and eliminating the painting process.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.18-18
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• 2003

Natural clays are composed of oxide layers whose thickness is about 1nm and cations existing between the layers. A number of these layers makes primary particles with a height of about 8∼10nm and these primary particles make aggregates with a size of about 0.1∼10$\mu\textrm{m}$. When layered silicate was made to be organophilic, by exchanging the interlayer cations with organic cationic molecules, the matrix polymer can penetrate between the layers to give a nanocomposite, where 1nm-scal clay layers exist separately in a continuous polymer matrix. These nanostructured hybrid organic-inorganic composites have attracted the great interest of researchers over the last 10 years. They exhibit improved performance properties compared with conventional composites, because their unique phase morphology by layer intercalation or exfoliation maximizes interfacial contact between the organic and inorganic phases and enhances interfacial properties. Since the advent of nylon-6/montmorillonite nanocomposite developed by Toyota Motor Co., the studies on layered silicate-polymer nanocomposites have been successfully extended to other polymer systems. They greatly improved the thermal, mechanical, barrier, and even the flame-retardant properties of the polymers.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.864-865
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• 1998

Permeation of $Ca^{2+}$ ions in PVC and flame-retardant polyolefin (FR) compounds for the sheath of medium voltage underground cables was studied. At $70^{\circ}C$ ion permeation increases fast at times of up to a few tens of hour and then at a relatively slow rate. The first fast increase was attributed to the diffusion of ions in the samples while the second slow increase of ion permeation was attributed to the permeation of $Ca^{2+}$ ions through the samples. It was also found that the diffusivity of $Ca^{2+}$ ions in FR compounds is much higher than that in PVC compounds.

• Fibers and Polymers
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• v.5 no.2
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• pp.83-88
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• 2004

In order to assess the potential of the hydroxy-containing polyamic acid (PHAA) synthesized from 3,3'-dihydroxy benzidine and pyromellitic dianhydride for a fire-safe polymer, the cyclization pathway of PHAA has been investigated using a model compound prepared from 2-aminophenol and phthalic anhydride. The reaction was monitored. by $^1{H-nuclear}$ magnetic resonance. N-(2-hydroxyphenyl) phthalamic acid is converted to N-(2-hydroxyphenyl) phthalimide at ca. 175$^{\circ}C$, showing endothermic reaction. The imide structure is rearranged to the benzoxazole structure over ca. $400^{\circ}C$. These results are similar with that of PHAA. According to pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) data, water and carbon dioxide are released during the cyclization and rearrangement reaction. One DMAc molecule is complexed with one carboxyl acid group in PHAA, which accelerates the imidization process to release more easily the flame retardant, water.

• Journal of information and communication convergence engineering
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• v.10 no.2
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• pp.123-128
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• 2012

In communication systems, there are various types of microstrip antenna that can be used for many applications. This paper mainly focuses on the simple design of an inset rectangular microstrip patch antenna to operate at a frequency of 2.45 GHz for rectenna design. The study involves using an high frequency structure simulator to design the antenna dimensions and to determine its performance. This antenna is based on a thickness of 1.6 mm flame retardant 4 (FR-4) substrate having a dielectric constant of approximately 4.7, an inset feed, and a ground plane. After simulation, the antenna performance characteristics such as its return loss, voltage standing wave ratio, gain, and radiation pattern were obtained and compared with the fabricated measured antenna.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.441-441
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• 2008

전지의 안전성은 리튬이차전지에서 가장 중요한 요소로 주목받고 있다. 대형전지나 하이브리드 자동차와 같은 저장장치는 안전회로의 발전이나, 안성성과 신뢰성이 높은 물질이 도입되어야 하는 선결조건이 있다. Triazine 유도체는 산업용 난연제로 알려져 있다. 이를 전지로 도입하기 위한 시도는 아직 보고되어 있지 않다. 난연성 물질을 전지에 첨가하면, 그 난연성을 증가하는데, 전지의 성능을 저해하는 단점을 많이 관찰해왔다. 이 논문에는 Triazine 유도체를 전해액 첨가제로 사용하여, 전지성능의 저해여부를 관찰하고 아울러 전지의 열안전성을 측정함으로서 난연 첨가제로서 가능성을 판단하고자 하였다. 실험결과는 전지의 성능을 저해하지 않고 전극의 열안전성을 개선하는 것을 보여주었다.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.737-740
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• 2000

Injection molded plastic parts have many appearance imperfections: weld line sink mark flow mark, gloss, shading, scratching, etc. Because these appearance faults have not accepted esthetically, so pastic parts are produced through painting or texturing. The purpose of this paper is to develop a paintless molded part of TV Mask Front, using numerical simulations and experiments. In order to minimize problems of injection, this study carried out computer aided injection mold filling simulations using MF/FLOW. Based on these numerical results we developed FR(Flame Retardant) HIPS and estabilished guidelines of part design, mold design, and processing conditions. We took effects of cost savings, inprovement of productivity, and utilization of recycling by eliminated painting process.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1460-1462
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• 2002

The test methods on materials of electrical power cable are used in accordance with 25 specifications of IEC, ASTM, ICEA, KS and KEPCO Spec. The validation of test methods were checked and stablished by solving the problems occurred during the test. These tests are flammability, degree of acidity of gases, amount of halogen acid gas, smoke density, oxygen index, amount of ion in semiconductor, void, amber, contaminant and water tree, crosslinked density. Then the performance of power cable made by A, B, C and D company were evaluated and compared.