• Corrosion Science and Technology
• /
• 제14권5호
• /
• pp.207-212
• /
• 2015

The purpose of this research was to synthesize fluorine modified waterborne polyurethane dispersion (F-WPU) by soap-free (internal emulsifier) emulsion polymerization techniques, to prepare coating solution based on fluorine modified waterborne polyurethane dispersion (F-WPU) and to compare the chemical and thermo-mechanical properties on the electrogalvanized steel sheet. Environmentally friendly F-WPU was prepared with a fluorinated polyol containing 60 wt% of fluorine. There are various ways of combining a wide variety of fluorinated polyols and diisocyanate to exhibit novel properties of waterborne polyurethane dispersion. Components of coating solution were largely divided into 4 kinds i.e., F-WPU, acrylic emulsion, silane coupling agent, and colloidal silicate. F-WPU coating solution on the electro-galvanized steel sheet showed excellent properties of corrosion resistance, alkali resistance and heat resistance, as compared to other coating solutions using a general waterborne resin. The F-WPU coating solution's reliable effects are possibly due to the fluorine atoms incorporated even in a small amount of F-WPU.

• 한국레이저가공학회지
• /
• 제16권4호
• /
• pp.12-16
• /
• 2013

For mass production of electronic devices, the processing of the printing roll is one of the most important key technologies for printed electronics technology. A roll of printing process, the gravure printing that is used to print the electronic device is most often used. The indirect laser processing has been used in order to produce printing roll for gravure printing. It consists of the following processing that is coating of photo polymer or black lacquer on the surface of printing roll, pattering using a laser beam and etching process. In this study, we have carried out study on the coating and etching for $25{\mu}m$ line width on the printing roll. To do this goals, a $4{\mu}m$ coating thickness and 20% average coating thickness of the coating homogeneity of variance is performed. The factors to determine the thickness and homogeneity are a viscosity of coating solution, the liquid injection, the number of injection, feed rate, rotational speed, and the like. After the laser patterning, a line width of $25{\mu}m$ or less was confirmed to be processed through etching and the chromium plating process.

• 한국재난정보학회 논문집
• /
• 제16권2호
• /
• pp.411-419
• /
• 2020

연구목적: 본 연구는 건축물 및 교통 시설물 등에 사용중인 강재류가 시간에 흐름에 따라 부식이 발생됨에 따라 부식된 강재의 성능을 향상시키고 유지보수 효율성을 확보하기 위해 수분 경화형 방식 코팅액을 개발하였고, 그 성능 시험을 통해 최적의 성분 배율을 결정하도록 하였다. 연구방법: 연구를 위하여 다양한 배율의 코팅액에 대해 내식성 평가, 물리적 성질 평가, 저장안전성 평가 등을 시행하여 그 결과를 분석하였다. 연구결과: 분석결과 마그네슘을 추가로 첨가한 액체에서 컷팅 부위에 발청이 거의 없어 방식효과가 우수하였고, 블리스터 발생도 거의 없어 가장 우수한 배율로 분석되었다. 결론: 본 연구를 통해 그 성능이 인정된 수분 경화형 방식 코팅액에 대해 향후 새로운 성분 배율 실험을 통한 기능 향상과 시행 확대를 위한 제도적 개선 노력이 필요하다.

• Korean Chemical Engineering Research
• /
• 제45권4호
• /
• pp.335-339
• /
• 2007

투명 polycarbonate(PC) 시트의 낮은 표면강도 문제를 극복하기 위해, 고굴절률을 보이는 유-무기 혼성 하드코팅 용액을 Sol-Gel 법을 이용하여 제조하였다. 코팅용액은 무기물 티타니아의 전구체인 TTIP(titanium tetraisopropoxide)에 유기물을 함유한 화합물인 GPTMS[(3-glycidoxypropyl) trimethoxysilane]를 첨가하여 제조하였다. 그 후 기재인 PC 시트에 스핀 코팅시키고, 열 경화 시켜 고굴절률을 보이는 하드코팅 필름을 제조 하였다. 코팅 용액 중의 GPTMS 함유량을 변화시킴에 의해 1.53-1.61의 굴절률을 갖는 코팅 막의 제조가 가능하였다. GPTMS의 첨가량이 증가할수록 코팅막의 굴절률은 감소하였으나, 연필경도는 증가하였다.

• 동력기계공학회지
• /
• 제21권2호
• /
• pp.5-13
• /
• 2017

This study has developed an organic/inorganic hybrid solution according to amount of $SiO_2$ polysilicate, and the amount of melamine is constant. The three types of cold rolled steel were evaluated a corrosion resistance properties by using these solutions. $US_3M_3$ and $US_{11}M_3$ solutions were generate a lot of corrosion. $US_7M_3$ solution was excellent in corrosion resistance, regardless of the steel type. The appearance of coating by $US_3M_3$ and $US_{11}M_3$ solutions were bumpy surface, and were a lot of fine defects. $US_7M_3$ solution was made a sophisticated molecular cross-linking structure inside the coating, it was a slick surface. Other characteristics are exhibited the excellent property for all solutions.

• 한국해양공학회지
• /
• 제24권5호
• /
• pp.67-74
• /
• 2010

Chromate conversion coating is a coating technique used to passivate aluminum, zinc, cadmium, copper, silver, magnesium, tin, and their alloys to slow corrosion. The process uses various toxic chromium compounds, which may include hexavalent chromium. The industry is developing less toxic alternatives in order to comply with substance restriction legislation, such as RoHS. One alternative is to develop a Cr-free coating solution. In this study, eco-friendly, Cr-free solutions (urethane solution S-700, organic/inorganic solution with Si LRO-317) were used. Test specimens were dried in a drying oven at $190^{\circ}C$ for 3, 5, 7, and 9 minutes. Corrosion resistance was evaluated using a salt spray test for 72 hours. The results show that the optimum corrosion resistance was achieved at $190^{\circ}C$ for five minutes for EGI and three or five minutes for HDGI, respectively. The adhesive properties of the two types of coating solutions were superior regardless of drying time.

• Korean Chemical Engineering Research
• /
• 제56권2호
• /
• pp.162-168
• /
• 2018

유기 및 무기 폴리실라잔을 우레탄 아크릴레이트와 혼합시킴에 따라 UV 경화형 하드 코팅 용액을 제조하였다. 이용액을 polymethylmethacrylate (PMMA) 시트에 흐름 코팅한 후 UV 경화시킴에 의해 UV 경화형 하드 코팅 도막을 제조하였다. 이 과정 중 폴리실라잔의 종류 및 첨가량을 변화시켜 코팅 도막의 물성에 미치는 영향을 살펴보았다. 그 결과 유기 폴리실라잔의 경우 $95^{\circ}$의 수접촉각을 보여 높은 소수성을 나타내었으며, 7H의 연필경도와 92%의 가시광선 투과율을 보였다. 반면에 무기 폴리실라잔을 코팅한 도막은 8H의 높은 연필경도와 기재와의 우수한 접착력 및 $82^{\circ}$의 수접촉각을 나타내었다.

• 한국응용과학기술학회지
• /
• 제24권4호
• /
• pp.399-409
• /
• 2007

Characteristics of polyaniline anti-corrosive coatings with various primer coating resins(epoxy resin, urethane resin, and others) and top coating resins(epoxy and acrylic urethane resins) were investigated through adhesion, acid resistance, alkaline resistance, water resistance, and anti-corrosion tests. As a result, the anti-corrosive properties of the prepared coatings using polyaniline varied with the types of primer and top coating resins. In this condition, the properties of adhesion, chemical resistance, and water resistance were found to be very satisfactory when using emeraldine base (EB) of polyaniline blended with single-packaged urethane and acrylic urethane resins as the primer coatings, and using acrylic urethane resin as the top coatings. Also, the anti-corrosive function of these anti-corrosive coatings was well preserved for 1000 hr in the salt spray experiment.

• Journal of Pharmaceutical Investigation
• /
• 제34권6호
• /
• pp.465-469
• /
• 2004

Colloidal gold nanoparticles might be of use as nano scale delivery systems of various therapeutic materials in the future. Recent studies have reported the feasibility of colloidal gold nanoparticles as gene delivery systems or protein delivery systems. In this study, we aimed to develop a short-step method useful for screening the optimal coating conditions of colloidal gold nanoparticles with proteins. We observed that colloidal gold nanoparticles have properties of changing its unique color when they were exposed to NaCl solution. Taking advantage of the color changing properties of colloidal gold nanoparticles, we applied the color testing method of colloidal gold nanoparticles solutions for evaluating the protein coating nature. Using bovine serum albumin as a model protein, we tested the protein coating of colloidal gold nanoparticles via the color change upon NaCl addition. The optimal coating concentration and coating conditions of colloidal gold nanoparticles with bovine serum albumin were fixed using the color testing methods. We suggest that the color testing method might be applied to optimize the coating condition of colloidal gold nanoparticles with other therapeutic proteins.

• 접착 및 계면
• /
• 제20권1호
• /
• pp.1-8
• /
• 2019

균일한 단일층(monolayer)의 형성은 박막 두께에서의 특성을 유지하면서 차광, 반사방지 등의 물리적, 화학적 기능을 강화할 수 있는 중요한 수단이다. 이전 연구에서도 여러 코팅 방법으로 단일층을 구현하였으나, 공정이 복잡하고 대면적화 하는데 어려움이 있었다. 이에 본 연구에서는 소량의 용액으로 대면적 코팅이 가능한 로드 (rod) 코팅법을 사용하여, $20cm{\times}20cm$ PET 필름 기판 위에 마이크로미터 크기의 PMMA 비드를 가장 치밀한 형태인 HCP(hexagonal closed packing)가 되도록 코팅을 진행하였다. 끓는점과 증기압이 다른 용매의 사용과 계면활성제의 적용, 플라즈마 처리를 통한 기판 에너지의 변화를 통해 형성되는 단일층의 수준을 관찰하였다. 본 연구를 통해 비드의 메니스커스, 용매와 비드의 인-척력, 표면에너지를 포함한 코팅 조건을 최적화함으로써, 최종적으로 단위면적당 비드가 차지하는 정도인 입자의 커버리지를 초기 대비 약 20% 정도 향상시켰고, 단일층에 영향을 주는 인자들을 확인하였다. 본 결과는 기존에 연구되었던 코팅 방법에 비해 간단하고 빠르게 대면적의 단일층(monolayer)을 형성할 수 있기 때문에, 광학필름과 센서 등 첨단 분야로의 잠재적 응용 가능성이 높다.