• Journal of the Korean Wood Science and Technology
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• 제27권3호
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• pp.73-81
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• 1999

This paper was intended to evaluate the effect of the blending condition of pigments on the packing structure of coating color and the interaction between pigments and latices on the optical and interior properties of coated paper. It has been studied many ways to modify the coating structure to induce the interaction among coating components as followings ; 1) to use dispersant for pigment, 2) to control the charge density and the type of surface charge of latex, 3) to support the water retention by adding water retention agent or flow modifier. This paper was performed through the introduction of interaction between pigments which were two kinds of clays and one precipitated calcium carbonate(PCC) and ionic latices of which anionic and amphoteric respectively under the certain blending condition of pigments where their blending ratio of clays to calcium carbonate was 70pph to 30pph. The reason is that packing volume of pigments was highest in that region and thixotropical behavior appears in measuring rheology of coating color. We measured the properties of coating color, interaction with pigments and latex, and properties of coated paper and its printability. As a results, we could find out that amphoteric latex had a great influence on the interaction with pigments, especially clays, no matter what grade and also affected the coating structure significantly in case that this blending condition was 70(clays) to 30(PCC). It produced a powerful effect on the forming of bulky and smooth coating structure and in turn improved the printability of coated paper.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 한국펄프종이공학회 1999년도 춘계학술발표논문집
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• pp.7-16
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• 1999

The aim of this research was to evaluate the influences of coating components and structures on ink absorbency. The ink absorbency was measured as porosity, K&N ink absorption, gloss and ink set-off. In order to obtain the relationship between the coating structure and the ink absorbency, the binder level was adjusted and two types of pigments were examined. One of the pigments was known to make the porous coating structure and the other one had strong ink affinity. The effects of coating components were studied by applying six different types of latex and various additives . In this research, CLC(cylindrical laboratory coater) and Prufbau printability tester were used. It was found that the decreasing latex dosage and introducing porous pigment were effective solutions to increase ink absorbency. However, the ink absorbency could not be improved by applying the fine pigment even though it had strong ink affinity. Among the characters of the latex, particle size and surface tension were found to have the strong effect on ink absorbency. The ink absorbency increased with large particle size and low surface tension latex. The additives were varied and it was found that applying to the top coating was effective.

• Proceedings of the KSR Conference
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.345-351
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• 2007

The research which it sees will confront to the coating with paint material and a coating with paint public law application of the river bridge and it will present it will sleep and it will execute, it will reach and a comparison - an analysis from the research which it tries to respect middle of special environment the polyurethane system which is a method coating with paint system and fluorine resin system, against a ceramic system it executed more an objectivity and rational fundamental data. With research method against each coating with paint evening sunlight a research investigation material and structure, it separated with spatial-temporal characteristic and economic viewpoint it executed. When considering overview from material viewpoint, fluorine resin system ceramic system polyurethane system pure with it is judged with the fact that it is excellent. There is a possibility of saying that the coefficient of friction of the fluorine resin system which uses the weapon quality zinc end coating compound ever so hard and polyurethane system is excellent ceramic system than from structure viewpoint. That fluorine resin system = polyurethane system ceramic system pure with it is excellent, it is judged from spatial-temporal characteristic viewpoint. It measures but it considered an internal troubles year grudge in the standard which becomes disturbance the place where it executes the market the expectation life person of the general bridge against 100 years the result fluorine resin system polyurethane system ceramic system which compares a materials unit cost pure with it appeared.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• 제19권5호
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• pp.457-460
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• 2006

Y doped zinc oxide (YZO) thin films were deposited on F doped $SnO_2$ (FTO) glass substrate by sol-gel method using the spin-coating system. A homogeneous and stable solution was prepared by dissolving acetate in the solution added diethanolamine as sol-gel stabilizer. YZO films were obtained after preheated on the hot-plate for 5minute before each coating; the number of coating was 3 times. After the coating of last step, annealing of YZO films performed at $450^{\circ}C$ for 30 minute. In order to confirming of a ultraviolet ray interruption and down-conversion effects, optical properties of YZO films, transmission spectrum and fluorescent spectrum were used. Also, for understanding the obtained results by experiment, the elestronic state of YZO was calculated using the density functional theory The results obtained by experiment were compared with calculated structure. The detail of electronic structure was obtained by the discrete variational Xa (DV-Xa) method, which is a sort of molecular orbital full potential method. The density of state and energy levels of dopant element were shown and discussed in association with optical properties.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• 제40권1호
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• pp.1-8
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• 2008

It is essential to use base papers having proper surface characteristics in coating operation for improving coated paper quality and coater runnability. To fulfill these purposes, surface sizing of coating base stock with oxidized starch is commonly practiced. Use of cationic starch for surface sizing improves coated paper quality since cationic starch penetrates less into paper structure. The immediate objective of this study was to examine the influence of surface sizing with starch solutions containing cationic polymers on the rheology of coating colors and the effect on physical properties of coated papers. Changes of rheological characteristics of coating colors placed on the plastic substrate surface sized with cationic and anionic starch were determined. Results of rheological test showed that cationic polymer surface sizing agent increased electrostatic interaction with coating colors and increased storage modulus. This new technology of using cationic polymer as surface sizing additive was considered to be advantageous for base papers at low basis weights since it would improve the coverage and optical properties of coated papers.

• Journal of the Korean institute of surface engineering
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• 제48권5호
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• pp.205-210
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• 2015

NbN coatings were prepared by ICP (inductively coupled plasma) assisted magnetron sputtering from a Nb metal target in $Ar+N_2$ atmosphere at various ICP powers. Effect of ICP on the microstructure, crystalline structure and mechanical properties of NbN coatings was investigated by field emission electron microscopy, X-ray diffraction, atomic force microscopy and nanoindentation measurements. The results show that ICP power has a significant influence on coating microstructure, structure and mechanical properties of NbN coatings. With the increasing of ICP power, coating microstructure evolves from the columnar structure of DC process to a highly dense one. Crystalline structure of NbN coatings were changed from cubic ${\delta}$-NbN to hexagonal ${\beta}-Nb_2N$ with increase of ICP power. The maximum nano hardness of 25.4 GPa with Ra roughness of 0.5 nm was obtained from the NbN coating sputtered at ICP power of 200 W.

• Journal of the Korea institute for structural maintenance and inspection
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• 제7권2호
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• pp.149-157
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• 2003

The purpose of this paper is to quantitatively investigate aging state of epoxy coating on containment structure at nuclear power plant. In order to evaluate an physical bonding of the epoxy coating, adhesion test was performed on a degraded epoxy coating on concrete specimens fabricated by accelerated aging experiment. In addition, impedance data by ultrasonic test were measured to compare with adhesion data. From almost 50 % of the specimens, aging phenomena of epoxy coating such as pin hole, blistering was discovered. To improve reliability on quality degradation of epoxy, co-relation between two kinds of different data was analyzed. By tracing co-related these data, it was possible to figure out physical state of as-built epoxy coating. The possibility to develop new methodology of time - dependent aging state on epoxy coating was found and discussed.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.291-295
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• 2005

The PEMFC behavior is quite complex and is influenced by several factors, including composition and structure of electrodes and membrane type. Fabrication of MFA is important factor for proton exchange membrane fuel cell. MFA of PEMFC with hot pressing and direct coating method were prepared, and performances were evaluated and compared each other. The effect of MEA preparation methods, hot pressing methods and direct coating methods, on the cell performance was analyzed by impedance spectroscopy and SEM. The performance of PEMFC wi th direct coat ing method was better than wi th hot pressing method because membrane internal resistance and membrane-:-interfacial resistance were reduced by elimination of hot pressing process in MEA fabrication. In addition the micro structure of MEA with direct coating method reveals uniform interface between membrane and catalyst layer.

• Proceedings of the Korea Concrete Institute Conference
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.721-726
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• 2003

The Durability of Concrete Structure is serverely degraded due to mainly carbonation, sulfate attack and chloride ion diffusion in concrete. The ultimate purpose of this study is to obtain how much the durability of Concrete Structure is improved according to the variation of physical properties in concrete or the frequency of surface coating on concrete. Where, variation of physical properties is a water-cement ratio or amount of air. The experiments are the chliride ion diffusion test, the lapid corrosion test, the lapid carbonation test, the test on resistance to freezing and thawing. Finally, this study shows that the effect by the surface coating method is better than the variation of physical properties in concrete.

• Journal of the Korean institute of surface engineering
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• 제36권5호
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• pp.398-405
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• 2003

The stainless steel wire requires good corrosion resistance and mechanical properties, such as drawing ability, combined with a high resistance to corrosion. For increasing drawing ability of stainless steel, Ni coating methods have been used in this study. However, there is no information on the electrochemical corrosion behavior of drawed wires after Ni coating. To investigate corrosion resistance and mechanical property of drawed wire, the characteristics of Ni coated wires have been determined by tensile strength tester, hardness tester, field emission scanning microscope, energy dispersive x-ray analysis and potentiodynamic method in 0.1 M HCl. The drawed stainless steel wires showed the strain-induced martensitic structure, whereas non-drawed stainless steel wire showed annealing twin in the matrix of austenitic structure. The hardness and tensile strength of drawed stainless steel wire were higer than that of non-drawed stainless steel wire. Electrochemical measurements showed that, in the case of drawed stainless steel o ire after Ni coating, the corrosion resistance and pitting potential increased compared with non-coated and drawed stainless steel wire due to decrease in the surface roughness.