본 연구에서는 용제를 전혀 사용하지않고 UV경화가 가능한 나노 실버 페이스트를 개발하였다. 무용제(solvent-free) 타입으로 개발한 나노 실버 페이스트의 점도 및 점탄성 측정하였다. 그리고 스크린인쇄로 패턴을 인쇄한 후에 UV 경화로 전극도막을 형성시켰다. 형성된 전극도막의 전도성, 연필경도, 접착력에 대해서 평가하였다. 또한 전극 도막 을 광 소결하여 전도성을 평가하였다. 마지막으로 전극도막의 경화특성은 TGA 및 FT-IR로 평가하였다. 이러한 결 과를 정리하면 UV경화만 시켰을 경우에는 전도성, 접착력, 경화특성에 대해서는 Paste(3)이 가장 우수하였다. 그러 나 광소결 후에는 Paste(1)이 가장 우수한 전도성을 얻을수있었다. 그 이유는 10nm 실버 파우더를 사용한 것이 소 결 특성이 가장 우수했기 때문이라고 판단된다.

Polydimethylsiloxane (PDMS) membranes were fabricated using a new class of UV-curable PDMS (UV-PDMS) and conventional heat-curable PDMS (Heat-PDMS) materials for n-butanol recovery. In addition, mixed matrix membranes (MMMs) were prepared using silicalite-1 particles as a additive to improve the recovery efficiency of n-butanol. To understand the structure-performance relationship, the surface/cross-sectional morphology and roughness of the PDMS membranes and MMMs were characterized using SEM and AFM, respectively. Consequently, when 20 % of silicalite-1 particles was loaded, the UV-curable MMM exhibited 58 % increased flux with similar separation factor compared to the heat-curable MMM, which is attributed to enlarged the effective membrane surface area resulting from its unique morphology.

In this study, (3,4-epoxycyclohexane)methyl 3,4-epoxycyclohexylcarboxylate acrylate was synthesized by reacting (3,4-epoxycyclohexane)methyl 3,4-epoxycyclohexylcarboxylate with acrylic acid to minimize hardening shrinkage and to improve heat resistance, which are known as disadvantages of photopolymers for 3D printing application. Urethane acrylate was synthesized by reacting 1,3,5-triazine-2,4,6-triamino alcohol, 2-hexylethyl acrylate, and isophorone diisocyanate in order to improve the mechanical properties without deteriorating the heat resistance. The physical properties before and after the synthesis of the acrylate and the mechanical properties when the urethane acrylate was applied were investigated. The reaction progress of the composite was examined by FTIR and 13C NMR. The heat deflection temperature, flexural strength, and surface hardness of the molding were measured. The curing behavior by Photo-DSC ultraviolet irradiation was also examined.

본 연구에서는 초소수성 실리카 에어로겔을 이용하여 단열 성능을 갖는 투명 필름용 유/무기 복합 코팅물질을 제조하였다. 바인더 물질로 사용된 자외선 경화형 우레탄 아크릴레이트 수지와 에어로겔과의 상용성을 위해 계면활성제(Brij 56)를 이용하여 에어로겔의 표면을 개질하였다. 개질된 에어로겔을 고분자 수지와 복합화한 코팅 용액을 폴리카보네이트 기지재에 코팅한 후 자외선경화를 통해 코팅필름을 제조하였다. 에어로겔이 10 vol% 함량으로 첨가되었을 때, 코팅필름의 단열성능은 측정된 열전도도 기준으로 순수 기지재 대비 28% 정도로 향상되었다. 또한, 코팅필름의 광투과율은 에어로겔이 50 vol%로 과량 첨가된 경우에도 80% 이상 높은 수준을 유지하였으며, 우수한 접착성(5B) 및 연필 경도(4H)를 보여주었다.

UV-Curable hybrid coatings were synthesized to improve the surface properties of plastic film. Organic-inorganic coating solutions were prepared by the sol-gel method using urethane-acrylate oligomer, acrylate monomer, photo initiator and tetraethoxysilane (TEOS). Methacryloyloxypropyltrimethoxysilane(MPTMS) was used as a silane coupling agent to improve chemical interaction between inorganic phases and UV curable acrylate. In this study, the surface hardness and adhesive properties were improved with the use of inorganic component. The experimental results showed that UV-Curable hybrid films containing aliphatic urethane oligomer, hexanedioldiacrylate, trimethylolpropanetriacrylate, hydroxy dimethyl acetophenone exhibited good surface properties. Also, the optimum curing conditions were investigated.

Ultraviolet curable coating solution was prepared with poly(ethylene glycol) acrylate oligomer and various mono and multi-functional acrylate monomers. The optical properties of UV cured coating layer on PET film with acrylate coating solution containing metal oxides, such as fumed silica and alumina, were also investigated to reduce light reflection on films. Poly(ethylene glycol) diacrylate which has 575 of average molecular weight was used as oligomer acrylate, and pentaerythritol triacrylate and dipentaerythritolpenta-/hexa acrylate were used as multi-functional acrylate monomers. Also, butyl acrylate was used to improve the adhesion as well as to reduce glass transition temperature to give a better flexability. 1-hydroxy cyclohexyl phenyl ketone was used as photoinitiator. We found out the metal oxides in acrylate coating solution showed a homogeneous dispersion from energy dispersive spectroscopy data. Transmittance and light reflection of coated PET film was measured with UV/vis spectrometer and gloss meter, respectively. When 1.00 g of both metal oxides was added into coating solution, the transmittance and the glossiness were reduced from 90% to 30% and from 190 GU to 35 GU, respectively. However, adding up to 1.00 g of the metal oxide into coating solution did not affect on the hardness of coating layer and adhesion between coated layer and PET film. Conclusively, we can control transmittance and light reflection of coated film by adjusting the amounts of metal oxide in coating solution.

본 실험에서는 스크린 인쇄 및 그라비어 인쇄 등 direct printing에 사용가능한 UV 경화형 Ag paste를 제조하였다. Ag 분말은 표면이 극성이므로 분말끼리의 응집력이 강하고, 비극성인 UV경화형 수지와의 친화성이 좋지 못해, 분산성이 좋지 못한 paste를 얻을 수 있다. 따라서 본 실험에서는 Ag 분말 표면을 올레인산 또는 도데칸 티올로 코팅함으로써, Ag 분말 표면을 비극성화하여 UV 경화형 수지와의 친화성을 높이는 것으로 Ag 분말 일차 입경 수준의 paste 분산특성을 얻었다. 제조된 Ag paste의 레올로지 특성을 검토한 결과, 표면 처리된 Ag paste의 경우, 낮은 전단 영역에서 형성된 Ag 분말과 바인더 수지와의 응집구조에 의해 shear thinning 거동을 나타내며, 높은 저장 탄성율을 갖게 되었다. UV 경화한 Ag 도막의 전기적 특성을 측정한 결과, UV 경화가 진행될수록 Ag 분말사이의 접촉이 증가하여 비저항이 감소하였고, 1500mJ/㎠에서는 10-3Ω․㎝의 비저항을 갖는 Ag 도막을 얻을 수 있었다.

In an attempt to reduce processing cost and to improve resolution of PDPs, micro mold transfer processing route for barrier ribs of plasma display panel was attempted. In this study, the parameters that may cause defects during the process were identified, which include the shrinkage during UV curing process, stress due to evaporation of organic components, and sintering shrinkage. Considering such parameters, UV curable paste was developed and barrier ribs of PDPs were successfully processed via the process. This work demonstrated the possibility of build-up route in manufacturing barrier ribs of PDP.