• 펄프종이기술
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• 제44권1호
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• pp.37-42
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• 2012

This study was carried in order to manufacture the high quality coated paper. High quality includes not only physical and optical properties of coated paper but also final print quality. In this study, new acrylic-styrene emulsion was polymerized in laboratory and compared with conventional styrene-butadiene latex. Low-shear viscosity of coating color was decreased with increasing acrylic-emulsion dosage. Small amount of acrylic emulsion addition increased water retention, but further addition decreased it. Acrylic-emulsion addition improved paper gloss, brightness and whiteness, but decreased PPS and opacity slightly. Ink gloss was increased with using No. 3 acrylic-emulsion due to lower ink setting properties. However No. 1 and 2 emulsion showed the opposite result. Surface strength of coated paper was increased with using No. 3 acrylic-emulsion. These results indicate that high quality coated paper can be manufactured with using No. 3 acrylic-emulsion.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.376-376
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• 2011

I-III-VI2 chalcopyrite compounds, particularly copper, indium, gallium selenide(Cu(InxGa1-x)Se2, CIGS), are effective light-absorbing materials in thin-film solar application. They are direct band-gap semiconductors with correspondingly high optical absorption coefficients. Also they are stable under long-term excitation. CIS (CIGS) solar cell reached conversion efficiencies as high as 19.5%. Several methods to prepare CIS (CIGS) absorber films have been reported, such as co-evaporation, sputtering, selenization, and electrodeposition. Until now, co-evaporation is the most successful technique for the preparation of CIS (CIGS) in terms of solar efficiency, but it seems difficult to scale up. CIS solar cells have been hindered by high costs associated with a fabrication process. Therefore, inorganic colloidal ink suitable for a scalable coating process could be a key step in the development of low-cost solar cells. Here, we will present the preparation of CIS photo absorption layer by a solution process using novel metal precursors. Chalcopyrite copper indium diselenide (CuInSe2) nanocrystals ranging from 5 to 20nm in diameter were synthesized by arrested precipitation in solution. For the fabrication of CIS photo absorption layer, the CuInSe2 colloidal ink was prepared by dispersing in organic solvent and used to drop-casting on molybdenum substrate. We have characterized the nanoparticless and CIS layer by XRD, SEM, TEM, and ICP.

• 한국정밀공학회지
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• 제31권6호
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• pp.497-504
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• 2014

The digital signage display is actively researched as the next generation of large FPD. To commercialize those digital signage display, the manufacturing cost must be downed with printing method instead of conventional photolithography. Here, we demonstrate a reverse offset printed TFT electrodes for the digital signage display. For the fabricated source/drain and gate electrode, we used Ag ink, silicone blanket, Clich$\acute{e}$ and reverse offset printer. We printed uniform TFT electrode patterns with narrow line width(10 ${\mu}m$ range) and thin thickness(nm range). In the end the printing source/drain and gate electrode are successfully achieved by optimization of experimental conditions such as Clich$\acute{e}$ surface treatment, ink coating process, delay time, off/set process and curing temperature. Also, we checked that the printing align accuracy was within 5 ${\mu}m$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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• pp.104-105
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• 2007

In this study, characteristics of silver ink-jet printing were investigated under various substrate treatments such as substrate heating, hydrophobic coating, and ultraviolet(UV)/ozone soaking. Fluorocarbon(FC) film was spin-coated on the polyimide (PI) film substrate to obtain a hydrophobic surface. Although hydrophobicity of the FC film could reduce the diameter of the printed droplets, the singlet images printed on the FC film surface showed irregularities in the pattern size and the position of the printed droplet along with droplet merging phenomenon. The proposed UV/ozone soaking of the FC film improved the uniformity of the pattern size and the droplet position after printing and substrate heating was very effective way in preventing droplet merging. By heating of the substrate after UV/ozone soaking of the coated FC film, silver conductive lines of 78-116 ${\mu}m$ line were successfully printed at low substrate temperatures of $40^{\circ}C$.

• 한국염색가공학회지
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• 제30권3호
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• pp.168-179
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• 2018

The modified surface of specialty carbon black(SCB) is one of the main technical factors for producing a uniform color and stable dispersion. In this work, the carboxylation or sulfonation process of SCB was used to improve the dispersive properties of hydrophilic solvents such as 1,6-hexanediol and propylene glycol monomethyl ether acetate(PGMEA). The results showed that the color strength of SCB DC2500G changed little with a range of 0.128~0.941(${\Delta}E$) compared to other SCB DC2500G material. In contrast, in the case of SCB EG410, there was a uniform color value with a range of 0.144~0.252(${\Delta}E$). Also, in our experiments, a modified SCB was confirmed by printing ink material as a melt coating paper. It may be possible that the SCB EG410 material can be advantageous as a gravure ink product. Finally, the modified SCB obtained from this research will have a large impact on the industry as a potential material for toners, paint, rubber, fillers, and other carbon black additives.

• 한국산학기술학회논문지
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• 제11권5호
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• pp.1741-1746
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• 2010

본 연구는 건축자재로 널리 사용되는 PVC 바닥상재 표면을 오염성 및 정전기로부터 보호하기 위하여 기존에 사용하는 광경화형 우레탄-아크릴 수지에 내오염/대전성을 향상시킨 광경화형 내오염 코팅액 개발에 관한 것이다. PVC 바닥상재용으로 사용되는 내오염성이 없는 우레탄-아크릴 수지에 4가 암모늄을 사용한 수용성 대전방지제와 아크릴용 대전방지제, 폴리우리탄용 대전방지제를 수지의 양 대비 함량(wt%) 5~20%로 변화하여 첨가한 후 배합하여 수지의 내오염/대전성을 향상시킨 내오염 코팅액을 제조하였다. 제조한 내오염 코팅액은 코팅 층의 두께조절이 가능한 코팅(Bar-coating)을 사용하여 PVC 바닥상재에 코팅 한 후 내오염성, 대전성, 부착력, 코팅두께 등의 코팅 층 표면물성을 평가하였다. 연구결과, 수지에 수용성대전방지제 15%를 혼합하여 제조한 코팅액을 Bar-coater No.12로 코팅한 코팅표면이 전기저항($3.24{\times}10^9{\Omega}/cm^2$), 내오염도(매직 Test, 먼지부착 Test) 및 부착력(100%) 모두 가장 좋은 물성을 보였다. 전반적으로 함량이 많을수록 전기저항과 오염도에서 우수한 것으로 나타났다. 그러나 대전방지제가 과량으로 들어간 경우 migration 현상이 보이는 것을 알 수 있었다.

• 한국산학기술학회논문지
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• 제11권9호
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• pp.3615-3620
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• 2010

본 연구는 건축자재로 널리 사용되는 PVC바닥상재 표면에 내오염성과 항균성을 증가시키기 위한 광경화형 코팅액 개발에 관한 것이다. PVC 바닥상재용으로 사용되는 우레탄-아크릴 수지에 수용성대전방지제와 항균제를 배합하여 오염 및 정전기로부터 상재를 보호하고 미생물에 의한 전염성질환을 예방할 수 있는 광경화형 내오염/항균 코팅액에 관한 실험을 수행하였다. 연구결과, 수지에 수용성대전방지제 15%와 항균제 1%를 혼합하여 제조한 코팅액을 bar-coater No.12로 코팅한 표면이 전기저항($10^9{\Omega}/cm^2$), 내오염도(매직 Test, 먼지부착 Test) 및 부착력(100%) 양호, 항균성(99.99%)로 가장 좋은 물성을 보였다.

• 한국정밀공학회지
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• 제27권9호
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• pp.11-15
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• 2010

In this study, to fabricate a low-resistance and high optical transparency electrode film, the following steps were performed: the design and manufacture of electroforming stamp, the fabrication of a thermal roll-imprinted polycarbonate (PC) patterned films, the filled low-resistance Ag paste using doctor blade process on patterned PC films and spin coating by conductive polymers. As a result of PC films imprinted line width of $26.69{\pm}2\;{\mu}m$, channel length of $247.57{\pm}2\;{\mu}m$, and pattern depth of $7.54{\pm}0.2\;{\mu}m$. Ag paste to fill part of the patterned film with conductive polymer coating and then the following parameters were obtained: a sheet resistance of $11.1\;{\Omega}/sq$ optical transparency values at a wavelength of 550 nm was 80.31 %.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.222-222
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• 2012

Metal oxide gas sensors based on semiconductor type have attracted a great deal of attention due to their low cost, flexible production and simple usability. However, most works have been focused on n-type oxides, while the characteristics of p-type oxide gas sensors have been barely studied. An investigation on p-type oxides is very important in that the use of them makes possible the novel sensors such as p-n diode and tandem devices. Monoclinic cupric oxide (CuO) is p-type semiconductor with narrow band gap (~1.2 eV). This is composed of abundant, nontoxic elements on earth, and thus low-cost, environment-friendly devices can be realized. However, gas sensing properties of neat CuO were rarely explored and the mechanism still remains unclear. In this work, the neat CuO layers with highly ordered mesoporous structures were prepared by a template-free, one-pot solution-based method using novel ink solutions, formulated with copper formate tetrahydrate, hexylamine and ethyl cellulose. The shear viscosity of the formulated solutions was 5.79 Pa s at a shear rate of 1 s-1. The solutions were coated on SiO2/Si substrates by spin-coating (ink) and calcined for 1 h at the temperature of $200{\sim}600^{\circ}C$ in air. The surface and cross-sectional morphologies of the formed CuO layers were observed by a focused ion beam scanning electron microscopy (FIB-SEM) and porosity was determined by image analysis using simple computer-programming. XRD analysis showed phase evolutions of the layers, depending on the calcination temperature, and thermal decompositions of the neat precursor and the formulated ink were investigated by TGA and DSC. As a result, the formation of the porous structures was attributed to the vaporization of ethyl cellulose contained in the solutions. Mesoporous CuO, formed with the ink solution, consisted of grains and pores with nano-meter size. All of them were strongly dependent on calcination temperature. Sensing properties toward H2 and C2H5OH gases were examined as a function of operating temperature. High and fast responses toward H2 and C2H5OH gases were discussed in terms of crystallinity, nonstoichiometry and morphological factors such as porosity, grain size and surface-to-volume ratio. To our knowledge, the responses toward H2 and C2H5OH gases of these CuO gas sensors are comparable to previously reported values.

• 대한기계학회논문집B
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• 제36권11호
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• pp.1135-1140
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• 2012

마스크를 이용하여 니켈 시드층의 형성 후 실버 도금을 통해 태양전지 상부전극을 형성하는 2 단계 전극형성 공정이 태양전지의 고효율화 방안으로 제안되었다. 본 연구에서는, 자외선 경화형 혹은 상변화 잉크를 고비용의 인쇄공정을 통해 마스크를 형성하는 방법을 대신하여, 코팅과 레이저의 복합공정을 통해 마스크를 형성하는 방법에 대해 제안하도록 한다. 마스크를 형성하는 물질로서 저비용의 저융점 왁스 혹은 플루오르카본 용액을 태양전지 웨이퍼 상에 코팅 후 레이저로 선택적으로 제거하여 전극패턴을 형성하였으며, 플루오르카본 용액 코팅이 왁스 코팅보다 패턴 균일도 측면에서 우수할 뿐만 아니라 통계적으로 0.16% 태양전지 효율증대를 유발한다는 점이 발견되었다.