• Polymer(Korea)
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• v.27 no.3
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• pp.189-194
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• 2003

Interfacial evaluation, damage sensing and cure monitoring of single carbon fiber/thermo setting composite with different curing processes were investigated using electro-micromechanical test. After curing, the residual stress was monitored by measurement of electrical resistance and then compared to various curing processes. In thermal curing case, matrix tensile strength, modulus and interfacial shear strength were higher than those of ultraviolet curing case. The shrinkage measured during thermal curing occurred significantly by matrix shrinkage and residual stress due to the difference in thermal expansion coefficient. The apparent modulus measured in the thermal curing indicated that mechanical and interfacial properties were highly improved. The reaching time to the same stress of thermal curing was faster than that of UV curing case.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.54-54
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• 2012

전통 날염방식(Silk Screen)과 디지털날염(Digital Textile Printing)을 비교해보면, 디지털날염은 디자인에서부터 날염까지의 전공정을 완전히 디지털화함으로서 다양하게 디자인할 수 있고 미묘한 색감의 흐름을 표현할 수 있어서 자연스러운 이미지의 표현이 가능하다. 그러나 현재 디지털날염을 피혁이나 직물에 적용하기에는 프린팅속도가 느려서 생산성이 낮고 이미지 내구성(세탁, 승화, 일광, 및 마찰견뢰도)이 낮은 등 많은 단점을 가지고 있다. 또한 신발산업은 현재 중국이나 동남아시아 등 개발도상국의 등장으로 수출의 국제적 경쟁시대에 접어들면서 대량생산이나 획일적인 디자인으로부터 벗어나 고부가가치 상품을 생산해야하는 과제를 안게 되었다. 한편 가죽에 응용가능한 잉크는 크게 수성, 유성, 용제형과 자외선 경화형의 잉크가 있으며 자외선 경화형 잉크는 자외선을 이용하여 기존의 잉크의 단점을 보완한 것이다. 자외선 경화형 잉크는 자외선 램프를 열원으로 하여 이온 또는 라디칼 중합, 광중합을 하며, 에너지 소비가 적어 경제적이며 시스템 가동시 비활성 기체가 필요하지 않다. 또한 자외선 경화형 기술은 상온에서 이용할 수 있으며 잉크의 경우 건조하는 데 걸리는 시간이 필요하지 않다. 또한 시스템을 가동 시키거나 중지 시키는 것이 쉬우며 고속으로 연속적인 일을 처리할 수 있다. 프린터의 크기가 작아 공간 효율이 유리하며 용제나 $CO_2$가 발생하지 않아 친환경적인 기술이라 할 수 있다. 따라서 본 연구에서는 자외선 경화형 시스템을 잉크에 적용하여 피혁 표면에 프린팅한 다음 그 견뢰도를 측정함으로써 그 효과를 알아보았다. 세탁에 의한 Matlab 측정값으로부터 용제형 잉크의 경우는 세탁 전, 후 line width가 큰 차이를 보이나 자외선 경화형 잉크의 경우는 그 차이가 적음으로부터 자외선 경화형 잉크가 용제형에 비해 색상 탈리가 적었음을 말한다. 또한 raggedness값 역시 마찬가지 결과를 보여 안료 색소와 피혁의 접착성이 향상된 것을 알 수 있다. SEM을 이용한 피혁의 표면과 단면 사진을 보면 용제형보다 자외선 경화형 잉크를 사용한 피혁이 좀 더 매끈한 표면을 보이는데 이것은 접착기능을 하는 아크릴레이트에 의해 균일한 날염이 가능하기 때문이라 고 생각된다. 이상의 결과로부터 자외선 경화형 잉크가 세탁, 마찰, 일광 견뢰도가 우수함을 알 수 있었으며 기존의 용제형 잉크를 대체할 수 있는 좋은 재료라고 생각된다.

• Proceedings of the Korean Fiber Society Conference
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• 2002.04a
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• pp.17-19
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• 2002

자외선 조사경화는 자외선조사에 의해 올리고머 등을 광중합/광가교하여 경화시키거나 섬유고분자의 표면을 처리하여 표면성질을 변화시키는 것으로 이를 이용한 섬유의 염색가공은 환경친화성, 에너지 절감, 높은 연속 생산속도, 고 해상도의 패턴 부여가능, 입체적인 구조물의 처리 가능, 장비의 소형화 및 설비면적의 감소 등 우수한 장점을 가지고 있어 차세대 첨단 염색가공기술로서 그 중요성이 부각되고 있다. [l] (중략)

• Applied Chemistry for Engineering
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• v.28 no.6
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• pp.626-631
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• 2017

Transparent plastic substrates require an improvement in properties such as surface hardness and thermal stability for optical applications. In this study, UV-curable organic/inorganic hybrids were synthesized to improve those properties. In order to make the optimum dispersion of inorganic component into the organic matrix, an in situ synthetic method was applied based on sol-gel reaction. Dispersion of the inorganic component in the organic urethane acrylate matrix was improved by using a proper combination of sol-gel reaction and fast UV-curing resulting in the formation of the transparent coating layer. Various alkoxy silanes were employed to vary both the degree of curing and coating properties of UV-curable organic/inorganic hybrids. UV-cured organic/inorganic hybrid coatings showed an improved surface hardness and thermal resistance depending on the content of inorganic component.

• Korean Chemical Engineering Research
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• v.46 no.1
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• pp.76-81
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• 2008

UV curable pressure sensitive adhesive (PSA) was made by blending the di-functional or hexa-functional urethane-acrylate oligomer with synthesized acrylic PSA. The change of adhesive property and removability were investigated at various oligomer contents under each oligomer. As the content of oligomer increased, the peel strength was increased before UV irradiation, but it was decreased after UV irradiation. Also, it was observed that the peel strength increased with decrease of storage modulus (G'), and that loss factor (tan ${\delta}$) of the adhesive material affected the adhesive properties and removability.

• Electronics and Telecommunications Trends
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• v.30 no.6
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• pp.42-49
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• 2015

질화물 반도체 기반 가시광 청색 Light Emitting Diode(LED) 기술은 디스플레이의 Back Light Unit(BLU)뿐 아니라 일반 조명에 활용되며 우리 실생활에서 매우 밀접하게 사용하고 있다. 가시광보다 짧은 파장을 가지는 자외선 LED의 경우 경화기 및 위폐감지기에 기존의 유해 가스를 사용하는 자외선 램프를 대체하고 있다. 자외선 광원의 또 다른 거대 시장으로 살균 및 정화, 의료 및 바이오 응용 시장에서 자외선 램프를 대체할 수 있는 자외선 LED 기술이 활발히 발전하고 있다. 본고에서는 이들 자외선광원 시장동향과 국내외 자외선 LED의 기술동향을 파악하므로 앞으로 연구개발의 방향을 모색하고자 한다.

• Journal of the Korean Wood Science and Technology
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• v.36 no.6
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• pp.121-129
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• 2008

Environmental friendly UV-curable coatings, having excellent hardness, gloss, mar and chemical resistance, are commonly used for the wooden flooring coatings. Especially epoxy acrylate oligomers are chosen for the wooden flooring coatings, due to their thermal stability and fast curing. In this study, we investigated the effect of the acrylate functionality on the thermal stability and surface hardness. The thermal degradations of monomers, oligomer, photoinitiator and formulated coatings with different acrylate functionality were measured using a thermogravimetric analysis (TGA). And the surface hardness was also measured with a pendulum hardness tester to compare relationship between the thermal stability and the physical property. The cured coatings became thermally stable by crosslinking during UV-curing. Both the thermal stability and surface hardness of cured coatings were improved with increasing acrylate functionality.

• Polymer(Korea)
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• v.35 no.4
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• pp.320-324
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• 2011

Two functional urethane acrylates were synthesized by using polycarprolactonediol (PCLD) and diisocyanate. The synthesized fuctional urethane acrylate was mixed with butyl acrylate(BA) or adhesion promoters, and their properties were investigated. To synthesize an excellent transparent urethane acrylate, isophorone diisocyanate(IPDI) was used. In addition, the effect of adding butyl acrylate for the improvement of shrinkage of urethane acrylate was studied. The results showed that the addition of butyl acrylate improved the shrinkage, and the optimum butyl acrylate content was 15 wt%. Both 2-ethyl hexyl acrylate (2-EHA) and ethyl acrylate(EA) were polymerized at $85^{\circ}C$ for 4 hrs to use as adhesion promoters, and the polymerized adhesion promoters were mixed to the UV-curing resin. The results showed that the adhesion properties increased with the increase of adhesion promoters content up to 15 wt%.

• Fiber Technology and Industry
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• v.7 no.3
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• pp.303-321
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• 2003

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.421-426
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• 2012

The effect of synthesis conditions such as various organic material and composition of organic-inorganic material in ozone resistance and surface characteristic of ultraviolet cured organic-inorganic hybrid coating film has been investigated. Organic-inorganic hybrid coating solution was prepared using tetraethoxysilane (TEOS), silane coupling agent methacryloyloxypropyltrimethoxysilane (MPTMS), 2,2,2-trifluoroethylmethacrylate, and various organic materials with acrylate group, bar-coated on substrates using applicator and densified by UV-curing. It was found that ozone resistance and surface hardness of the coating film was increased with contents of TEOS. It was also found that ozone resistance of coating film was increased with contents of 2,2,2-trifluoroethylmethacrylate. On the other hand, surface hardness was decreased with increase of 2,2,2-trifluoroethylmethacrylate. In addition, Surface hardness of coating film was increased with the addition of aliphatic urethane acrylate. It was also found that the transmittance of coating films was not influenced by content of TEOS and 2,2,2-trifluoroethylmethacrylate. In addition, the coating film exhibited high transmittance of above 90%.