• 한국분말재료학회지
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• 제25권5호
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• pp.379-383
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• 2018

Silica is used in shell materials to minimize oxidation and aggregation of nanoparticles. Particularly, porous silica has gained attention because of its performance in adsorption, catalysis, and medical applications. In this study, to investigate the effect of the density of the silica coating layer on the color of the pigment, we arbitrarily change the structure of a silica layer using an etchant. We use NaOH or $NH_4OH$ to etch the silica coating layer. First, we synthesize ${\alpha}-FeOOH$ for a length of 400 nm and coat it with TEOS to fabricate particles with a 50 nm coating layer. The coating thickness is then adjusted to 30-40 nm by etching the silica layer for 5 h. Four different shapes of ${\alpha}-FeOOH$ with different colors are measured using UV-vis light. From the color changes of the four different shapes of ${\alpha}-FeOOH$ features during coating or etching, the $L^*$ value is observed to increase and brighten the overall color, and the $b^*$ value increases to impart a clear yellow color to the pigment. The brightest yellow color was that coated with silica; if the sample is etched with NaOH or $NH_4OH$, the $b^*$ value can be controlled to study the yellow colors.

• 펄프종이기술
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• 제47권5호
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• pp.134-140
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• 2015

This study was carried out to evaluate whether EVAc, acryl latex and biobinder could substitute the part of SB latex for pre-coating color formula or not. Different coating colors prepared through the substitution of 30% SB latex with EVAc, acryl latex, and biobinder were applied for pre-coating layer. 100% SB latex is used as a binder for top coating color. The optical properties, gloss, roughness, stiffness, dry- and wet-pick strength were measured. There were no significant differences in the brightness, whiteness, opacity, roughness, ink set-off and gloss of paper coated with 5 different coating colors. However the stiffness, dry- and wet-pick strength were somewhat lower than those of conventional coating color which 100% SB latex was used as a binder. Although the part of SB latex could be substituted with EVAc, acryl latex and biobinder without sacrificing the qualities of coated paper. Further researches on the improvement of stiffness, dry- and wet-pick strength, and the optimization of rheology of coating color in order to improve the qualities of coated paper are strongly recommended.

• 펄프종이기술
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• 제29권3호
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• pp.17-25
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• 1997

Natural water-soluble polymers such as starch, casein and carboxy methyl cellulose(CMC) have been limited in their uses. However, the proper water retention of coating colors can not be obtained without addition of these polymers. Furthermore, the coating runnability and the physical properties of coated paper were not also satisfied. Therefore, the objective of this study was to synthesize the water retention and flow modifiers which can improve the water retention and flow properties of coating colors. We have measured physical properties of flow modifiers and coating colors which included flow modifiers. The viscosity of flow modifiers was very low at acid pH, and rapidly increased at about pH 7, and gradually reached to equilibrium at alkali pH. Such an increase comes from the molecular weight of flow modifiers and the amount of acrylic and methacrylic acids. The viscosity of coating color containing the flow modifiers was lower than that containing CMC. However, both of them had little difference in water retention. The water-phase viscosity of synthetic modifier containing coating color was either higher or similar compared to that of CMC containing coating color. The high shear viscosity of coating colors was low. Therefore, it can be concluded that the synthetic flow modifiers are very useful for improvement of flow properties and water retentions.

• 펄프종이기술
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• 제30권3호
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• pp.63-72
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• 1998

This research was intended to evaluate the effect of carboxymethylcellulose(CMC) on the coating structure and surface strength of coated paper prepared with amphoteric latex based coating color. Printability and optical properties of coated papers were compared. The influence of the consolidation behavior of coating color on the coating structure and the surface strength of coated paper was investigated. Compared with the conventional anionic latex, amphoteric latex formed bulkyer, smoother and more porous coating layer, which in turn, restricted binder migration in the coating layers, and facilitated immobilization of coating colors. However, dry pick strength of coated paper was decreased. The addition of CMC to these systems had strongly influenced on. the consolidation behavior and porosity in the dry state, through forming the network structure of coating layers by the interaction with amphoteric latex particles. Thus, printability and optical properties of coated papers were improved. Results indicated that amphoteric latex could be practically applied to the paper coating to improve printability and optical properties of coated papers.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1386-1388
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• 2009

We report on a new method of fabricating color filters based on selective wetting of color inks. The reversible formation of a hydrophobic layer provides sequential generation and protection of successive color filter patterns through a simple coating process. The transmittance and geometrical properties of the fabricated color filter were described.

• 펄프종이기술
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• 제43권5호
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• pp.49-54
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• 2011

Curtain coating has been considered as the best coating technology because it is a coating technology that forms contour coating layer with better coverage. To increase the curtain stability surfactants are being used. In this study, the effect of a surfactant on the stability of curtain coating colors was examined by evaluating dynamic surface tension with a bubble surface tensiometer. Di-2-ethylhexyl sodium sulfosuccinate was used as a surfactant since it showed low dynamic surface tension at low surface age. And we evaluated the influence of surfactant on coating color properties including surface tension, viscosity and curtain stability. The surface tension of coating color was decreased when surfactant addition was increased up to 0.5 pph, but it was leveled off at 0.3 pph of surfactant addition. With the increase of surfactant addition rate, viscosity of coating color were increased. Micelles formed by surfactant contributed to the increase of the viscosity. Curtain stability was improved with the addition of surfactant until it reached up to 0.5 pph. Excessive addition of surfactant (> 0.5 pph) didn't improve curtain stability. This was attributed to Marangoni effect(self-healing) and decreasing of curtain thickness.

• 한국인쇄학회지
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• 제22권1호
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• pp.19-28
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• 2004

A piece of coating color or base paper picked during printing is called coating pick. Loosely bonded materials of coating color or broken piece of fiber could be adhered to the blanket or would be mixed with ink during printing. Because the coating pick can make troubles in printing press such as piling, hickey and collecting, the coating pick of a paper has been one of the most serious problems in printing. In this paper, two influential factors to the coating pick in the printing, those are latex content and ash content of the coating color, are studied. The surface resistance of coating paper is directly proportional to the latex content, otherwise inversely proportional to the ash content. We propose a different way to evaluate the picking and used a homemade pick test device.

• 펄프종이기술
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• 제31권4호
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• pp.16-22
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• 1999

The quantitative analysis of SB latex contents in coating color and coated paper was investigated with FT/Raman spectroscopy. From the measured FT/IR and FT/Ramon spectra, the peaks of coating color were compared with those of each compoents . Calibration curves were obtained by the area of latex peaks and PLS method of QuantIR program. The relation of predicted values in PLS method and actual values in coating mixtures and coating layer was examined. The components of coating layer in coated paper were investigated by EDS , X-mapping and SEM, The contents of latex in z-direction were calculated in the coating layer of unknown coated paper. The latex concentration measurements of Top layer and Pre layer in double coated paper show that each layer has different value. In single coated paper, it is clear that the latex concentration is highest at the surface and decreases with an increase of depth. From those results it is indicated that the latex migrates to the coated surface. The result of this study may be applied to the binder migration study and the quality control in paper mill.

• 대한인간공학회지
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• 제17권2호
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• pp.25-32
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• 1998

A combined PC and TV monitor has been developed in several companies. The characteristics of physical user interface in this monitor are likely to vary from existing monitors. Therefore, two experiments to investigate the physical interface characteristics of this monitor were conducted. The first experiment was to investigate the characteristics of color perception with monitor coating (coating vs. non-coating) and screen brightness (30fL vs. 35fL) in the PC mode. The second experiment was to investigate the characteristics of luminance contrast with monitor coating and image movement (static vs. dynamic) in the TV mode. Twenty-three subjects (male 12, female 11) were participated in this experiment. In the first experiment, average color temperatures were obtained in all experimental conditions. There was a significant difference between coating and non-coating screen at 0.1 level. In the second experiment, average luminance contrasts were obtained in all experimental conditions. There was a significant difference between coating and non-coating screen at 0.05 level. In addition, there was a significant difference between static picture and dynamic picture at 0.1 level.

• 한국조리학회지
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• 제21권6호
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• pp.303-311
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• 2015

무설탕 원료로서 xylitol, maltitol, isomalt, erythritol 및 sorbitol을 껌의 코팅 재료로 사용하여 코팅 공정 중 제조특성과 외관을 비교하였고, 코팅 후 표면 균일성, 색택 변화, 코팅시간, 건조시간 등을 비교하였을 때 maltitol이 가장 우수하였으며, erythritol과 sorbitol은 코팅품질과 코팅시간이 길어지는 등의 생산성과 품질면에서 껌의 코팅 소재로는 부적합하였다. 이에 maltitol, xylitol 및 isomalt로 코팅한 껌을 고온 저장하면서 코팅층의 색택 변화를 분석한 결과, maltitol 코팅껌의 경우 $80^{\circ}C$, 1일간 저장시 ${\Delta}E$값은 2.88로 상온보관 시료와 비교하여 색상의 변화가 비교적 작았으나, xylitol과 isomalt 코팅껌은 색상의 변화가 크게 나타났다. 또한, maltitol 코팅껌을 polypropylene 포장재에 넣고 저장 중 색택의 변화를 관찰한 결과, $40^{\circ}C$이하에서는 색택의 변화가 적었으며, $60^{\circ}C$에서도 30일간 저장시 색차는 3 이하로 나타나 유통과정 상 품질의 변화가 적을 것으로 판단되었다. 그러나 본 실험은 색상변화로만 저장 중 변화를 평가하였던 바, 향후 당알코올류를 코팅제로 사용한 코팅껌의 저장 중 품질에 대한 추가적인 연구가 진행되어야 할 것이다.