• 한국산학기술학회논문지
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• 제11권5호
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• pp.1773-1777
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• 2010

광경화(UV-curing)에 의한 PVC 바닥상재 코팅기술은 PVC 바닥상재 질의 개선을 위하여 사용되는 것이다. 본 연구에서 사용한 폴리우레탄 아크릴레이트 수지는 반응성 모노머, 광개시제, 그 외 첨가제를 배합하여 제조하였고, 올리고머는 상용화된 지방족 우레탄 아크릴레이트를 사용하였다. 제조한 코팅액을 바코팅(bar-coating) 방법으로 PVC 바닥상재에 코팅한 후 광경화법을 이용하여 상재표면에 코팅층을 형성하였다. 코팅에 사용된 코팅액은 FTIR로 측정하여 특성을 확인하였으며, PVC 상재 표면에 형성된 코팅층의 물성은 광택과 부착력으로 평가하였다. 코팅층의 물성은 코팅조성과 공정조건에 영향을 받았다.

• 한국염색가공학회지
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• 제18권6호
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• pp.49-56
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• 2006

Surface treatment using UV irradiation was carried out to improve optical properties of polarizing films. The effects of UV energy of the UV-treated PVA films were investigated by measuring reflectance, surface roughness, contact angles, ESCA, and ATR. Reflectance decreased at wavelength of 450 nm or less and surface roughness increased with increasing UV energy. Water contact angle increased in the irradiated PVA films and surface energy decreased with increase in w energy. An analysis showed that the OH groups were broken and some new groups were introduced such as C=C and C=O bonds together with increased $O_{1s}/C_{1s}$, resulting in the observed surface modification effect. Surface modified PVA polarizing films showed improvement in light transmittance of polarizing films at high wavelength region without deteriorating polarization efficiency, which was not affected by UV irradiation sequence during manufacturing processes such as coloring and drawing.

• 폴리머
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• 제39권2호
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• pp.256-260
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• 2015

우레탄 아크릴레이트에 montmorillonite(MMT)를 첨가한 UV 경화형 나노복합체 제조 시 사용하는 광개시제의 종류에 따른 기계적 성질 및 내흡수성을 조사하였다. 1 wt%의 MMT가 첨가될 경우 가장 우수한 인장강도와 내흡수성을 나타내었으며, 광개시제의 경우 기존의 benzyldimethylketal 계열 광개시제와 bisacyl phosphine oxide 계열의 광개시제를 함께 사용할 경우 3 wt%의 MMT 함량에서도 사용된 UV 램프의 방출 파장대인 340~450 nm에서의 광흡수가 강화되어 나노복합체의 경화거동에 보다 효과적인 것으로 확인되었다.

• 한국세라믹학회지
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• 제43권3호
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• pp.185-192
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• 2006

The effects of annealing on structural and electrical properties of ITO/PES (Indium Tin Oxide/Polyethersulfone) films was investigated. Amorphous ITO thin films were grown on plastic substrates, PES using low temperature DC magnetron sputtering. Various post annealing techniques were attempted to research variations of microstructure and electrical properties: i) conventional thermal annealing, ii) excimer laser annealing, iii) UV irradiation. The electrical properties were obtained using Hall effect measurements and DC 4-point resistance measurement. The microstructural features were characterized by FESEM, XRD, Raman spectroscopy in terms of morphology and crystallinity. Optimized UV treatment exhibits the enhanced conductivity and crystallinity, compared to those of conventional thermal annealing.

• 천문학회보
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• 제35권2호
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• pp.42.1-42.1
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• 2010

We present ultraviolet (UV) photometric properties of dwarf galaxies in Fornax cluster and Ursa Major group in comparison with Virgo cluster using GALEX data. We construct UV color-magnitude relations (CMRs) of dwarf galaxies matching with available optical photometry and SDSS data. Majority of dwarf galaxies in Fornax cluster show sequence in UV CMRs consistent with that of dwarf elliptical (dEs) in Virgo cluster indicating similar age and metallicity properties of dEs in two clusters. The dS0 sequence in Fornax cluster is not distinct as much as that in Virgo cluster. Dwarf galaxies in outer region of the Fornax cluster show more bluer UV colors with a wide scatter in CMRs, which indicates recent star formation activity. We show that the UV colors of dwarf galaxies are related with the distribution and strength of the X-ray emission in the cluster. In contrast to the Fornax cluster, most dwarf galaxies in Ursa Major group are located in the blue cloud showing recent or on-going star formation, and few galaxies show characteristics of dEs. We discuss relationship between UV properties of dwarf galaxies and different environment of cluster.

• 한국인쇄학회지
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• 제18권1호
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• pp.59-69
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• 2000

The characteristics of liquid crystal polymer composite(LCPC) films are possessed of large-area and flexible display, polarizer free, high contrast, wide angle of visual filed and high responsiveness. It is well known that the LCPC films consisting of a continuous LC phase embeded in a three-dimentional network of polymer matrix are formed by photopolymerization-induced phase separation. In this study, we have investigated the point that both liquid crystals and polymer having different properties have to coexiste as composed films. The purpose of this study has been the development of new application with liquid crystals and UV-curable monomers. In the results abtained on the miscibility of nematic liquid crystal and UV-curable resins, difunctional monomer HX-620 turned out to shows the best. From the results abtained on structures, electro-optical properties and dynamic visocoelasticity for LCPC films, the best mixing ratio of monomer to LC mixture were 3/7(photoinitiator; 4wt%) by weight, and this ratio has been provided the most thermal stability for LCPC films. In the results abtained on structure and discoloration properties of LCPC films, it has been demonstrated that consiste of a 8:2 mixture of chiral nematic liquid crystal and HX-620 has the greatest domain and it was the best discoloration.

• 한국수소및신에너지학회논문집
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• 제28권1호
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• pp.77-84
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• 2017

In this study, Poly-urethane acrylate (PUA) was synthesized by the reaction between Polycaprolactonetriol (PCLT) and Isophorone dissocyanate (IPDI) and hybridized with inorganic materials. Tetraethylortho silicate (TEOS) and nano clay (Closite 20A) were used as inorganic particles. For the hybridization of TEOS with PUA, sol-gel method is used, in which TEOS is made into spherical particle in the firsthand. In the case of Nano clay, hybridization is carried out through the dispersion as Nano clay has a layered structure. The solution of PUA hybrid was made into a film after UV curing and its thermo and electrical properties were measured. The experimental analysis and result demonstrate that the PUA hybrid shows an improved thermal properties and lower dielectric constant than that of the non-hybrid PUA. The trend of improved properties was different depending on structure of inorganic materials.

• 접착 및 계면
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• 제9권2호
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• pp.32-37
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• 2008

광개시제 함량이 0.5 wt%, 1 wt%, 2 wt%인 UV 경화형 분체도료를 배합하고 낮은 온도에서도 용융되는 수지를 선택하여 열민감성 기재에 적용이 가능함을 알아보았다. 열민감성 기재로는 PVC와 목재제품(MDF, 합판 등)을 선택하여 표면경도, 광택, 부착력을 통해서 기재와의 상관관계를 알아보았다. 광개시제 양이 증가할수록 가교밀도가 증가하여 도막이 brittle해지는 경향을 보였고, 그에 따라 부착력이 감소하였다. 열민감성 기재에 적용한 결과, 표면경도는 기재에 영향을 받지 않았지만 광택은 기재에 따라서 차이가 나타났다. 그리고 UV 경화형 분체도료의 부착력은 열민감성 기재에 적용하기에 충분하였다. 본 연구 결과, UV 경화형 분체도료에서 광개시제 함량이 중요한 인자이며 열민감성 기재에 적용이 가능함을 확인하였다.

• 접착 및 계면
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• 제13권4호
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• pp.156-162
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• 2012

UV 경화형 우레탄아크릴레이트 수지와 유기화클레이를 혼합한 후 UV를 조사하여 경화시킴으로써 폴리우레탄-클레이 나노복합체를 제조하였다. 유기화클레이로서는 Closite20A (C20A) 및 이를 실란처리하여 표면에 아크릴기를 도입한 아크릴변성 C20A를 사용하였다. XRD와 TEM 분석으로부터 제조된 나노복합체는 삽입형 나노복합체이며, 아크릴 변성시킨 C20A가 변성시키지 않은 C20A에 비해 더 잘 분산되는 것을 알 수 있었다. DMTA, 연필경도분석, PET 필름에의 부착성 시험으로부터 클레이 첨가에 의해 유리전이온도와 저장탄성률 및 연필경도가 증가하고 PET 필름에의 부착성이 향상되며, 이러한 물리적 특성의 증가는 아크릴 변성시킨 C20A를 함유한 나노복합체에서 더 크게 발현됨을 알 수 있었다. 또한, 클레이 첨가에 의해 UV경화 시 수반되는 수축을 저하시킬 수 있음을 알았다. 한편, 제조된 나노복합체는 우수한 광투과도를 나타내었으나, 광택도는 나노입자를 함유하지 않은 경우에 비해 다소 저하되었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 추계학술대회 논문집
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• pp.251-252
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• 2008