• 한국전기전자재료학회논문지
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• 제29권4호
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• pp.247-249
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• 2016

In this study, we investigated the color change of the normal light gray granite as the high value color granite. By coating the metal catalyst liquid on the surface of granite stone, the metal particles were penetrated into the granite and the color of granite was changed permanently through the annealing treatment. To increase penetration depth into the granite, we used DC (direct current) bias. Two kinds of bias were used such as DC bias and pulse DC bias. And the penetration time was changed as 30 and 60 min. In all cases, the color granite were successfully obtained. Regardless of the catalyst reaction time, the penetration depth was increased by using the bias treatment. We obtained a penetration depth of 21 mm with the DC pulse bias during 60 min.

• 한국재료학회지
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• 제31권7호
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• pp.403-408
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• 2021

Various surface colors are predicted and implemented using the interference color generated by controlling the thickness of nano-level diamond like carbon (DLC) thin film. Samples having thicknesses of up to 385 nm and various interference colors are prepared using a single crystal silicon (100) substrate with changing processing times at low temperature by plasma-enhanced chemical vapor deposition. The thickness, surface roughness, color, phases, and anti-scratch performance under each condition are analyzed using a scanning electron microscope, colorimeter, micro-Raman device, and scratch tester. Coating with the same uniformity as the surface roughness of the substrate is possible over the entire experimental thickness range, and more than five different colors are implemented at this time. The color matched with the color predicted by the model, assuming only the reflection mode of the thin film. All the DLC thin films show constant D/G peak fraction without significant change, and have anti-scratch values of about 19 N. The results indicate the possibility that nano-level DLC thin films with various interference colors can be applied to exterior materials of actual mobile devices.

• 한국안광학회지
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• 제4권2호
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• pp.123-128
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• 1999

25mol% CoO가 고용된 $Al_2O_3$계 코팅박막을 졸-겔법으로 제조하고 열처리온도의 변화와 코팅 횟수에 따른 광투과 스펙트럼과 표면반사율과 색상의 변화를 분석 연구하였으며 그 결과는 다음과 같다. $Al_2O_3$-CoO계 박막의 UV-Visible 영역에서의 분광투과율은 약 600nm를 최고 정점으로 하여 파장의 감소와 함께 감소하였으며, 평균 분광투과율은 $300^{\circ}C$(61%), $400^{\circ}C$(55%), $550^{\circ}C$(53%)로 열처리온도가 증가할 수록 광투과율이 감소하는 경향을 보였다. $550^{\circ}C$에서 열처리한 $Al_2O_3$-CoO계 박막의 1~5회 범위의 코팅 횟수에 따른 UV-Visible 영역에서의 분광투과율은 코팅 횟수의 증가와 함께 2차 함수 곡선을 따라 급속히 감소하였다. Indentor penetration method에 의한 $Al_2O_3$-CoO계 박막의 microhardness는 $300^{\circ}C$($370{\times}10^7N/m^2$), $400^{\circ}C$($405{\times}10^7N/m^2$), $550^{\circ}C$($417{\times}10^7N/m^2$)로 열처리 온도의 증가와 함께 증가하였다. 박막의 표면반사광의 스펙트럼은 열처리 온도의 증가에 따라 반사용은 낮아지며, Db값이 20~30 범위에서 높은 값으로 전이하여 황색의 심도가 깊어졌다. 박막의 코팅 횟수에 따라서는 1회(600nm), 2회(560nm), 4회(530nm)로 낮아지다가 5회 (575nm)로 다시 높아지는 결과를 보였으며 yellow에서 greenish-yellow로 변화하다가 Db가 약 50에 달하는 deep yellow로 전이하였다. 명도는 1회(69.77), 2회(68.64), 3회(63.14), 4회 (64.94), 5회(60.42)로 코팅 횟수의 증가에 따라 점차 낮아지는 경향을 보였다.

• 한국응용과학기술학회지
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• 제28권3호
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• pp.335-344
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• 2011

The pearlesent pigment has received attention in a diversity of fields like cosmetics, inks, paints and so on. Ferric Ferrocyanide, one of the nano sized pearlescent pigment, is a kind of surface modification pigment that covers a metal oxidized substance or a coloring agent with uniform thickness. Characteristics of pearlescent pigment are various interference color, intense gloss effect and a three-dimensional effect. We synthesised the pearlesent pigment that ferric ferrocyanide can be deposited on the titania/mica surface by hydrothermal synthesis method. The process parameters are concentration of precursor, controlling pH and reaction temperature. The optimun conditions is that amount of iron(III) chloride hexahydrate is 3.1 wt% and amount of potassim ferrocynide trihydrate is 3.6 wt% in the started pH 4.5 at $70^{\circ}C$. The coating rate and coating efficiency of ferric ferrocyanide was about 1.47 % and 96.7 %, respectively. The synthesised pearlesent pigment was characterized by SEM, XRD, FT-IR and EDS.

• 한방재활의학과학회지
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• 제23권3호
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• pp.149-157
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• 2013

Objectives This study was designed to: (1) investigate the clinical feature of tongue diagnosis, (2) make an observation of significant changes in tongue diagnosis according to the patient's physical condition and laboratory result and (3) identify clinical efficacy of tongue diagnosis. Methods 300 patients' tongue diagnosis results were analyzed and the patients were divided to each group according to the physical condition and laboratory result. Then, chi-square test was performed to assess statistical significance between tongue diagnosis results of each group. Results As a result of analyzing the spread of tongue diagnosis according to the patient's physical condition and laboratory result, 18 groups had statistical significance related to specific tongue color and tongue coating. Conclusions Even if there would be possible misinterpretations in one-to-one match between the tongue diagnosis and certain diseases, we identified that tongue diagnosis results were changed somewhat related to patient's physical condition with some tendency and tongue diagnosis could be used for meaningful clinical diagnostic tool.

• 펄프종이기술
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• 제44권4호
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• pp.91-98
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• 2012

This study was carried out in order to evaluate the effects of ultra fine precipitated calcium carbonate (UFPCC) on properties of coating color, coated paper and off-set printability. It was found that blending of UFPCC increased the low-shear viscosity and water retention of coating color. The smaller the particle size, the more significant the effect of it. When the blending ratio of UFPCC was increased, brightness, whiteness and opacity of the coated paper were improved, while paper gloss was decreased due to the increase in roughness. When the UFPCC with the average particle size of $0.12{\mu}m$ was used, the ink receptivity during off-set printing was improved while print gloss was maintained or a little decreased. It was also observed that the dry-pick and wet-pick strength of coated paper were improved by the use of UFPCC. In conclusion, it is possible to produce the low gloss matt paper with the use of UFPCC since it could improve the optical properties and ink receptivity of coated paper.

• 펄프종이기술
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• 제45권6호
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• pp.36-43
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• 2013

Effects of blending of PCC manufactured with emission gas occurred at mill on the characteristics of coating color, optical and printing properties of coated paper were investigated in order to evaluate the possibility of its use as a raw material for producing environmentally friendly coated paper. Low shear viscosity and water retention value of ground PCC 1(d50 = $6.303{\mu}m$) were higher than those of ground PCC 2(d50 = $3.149{\mu}m$). Ink set properties of ground PCC 1 and ground PCC 2 were inferior to that of PCC 3. Thus, the reducing of particle size was required in order to overcome the inferior ink set properties. Ground PCC 1 had a similar properties to clay, and it showed the possibility that ground PCC 1 could be used to produce matte grade coated papers. However, it was required to improve the stability(particle shape, particle size, and compatibility with chemicals used in coating color formulation) in the case of blending with GCC in order to keep the qualities of coated paper.

• 한국응용과학기술학회지
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• 제32권3호
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• pp.528-535
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• 2015

인류는 아름다움을 추구하는 경향이 있으며, 진주는 부와 신분의 상징으로 수 천년 동안 많은 사람들의 사랑을 받아 왔다. 현재의 인조진주는 밝은 색감을 갖고 코팅공정이 쉬운 유기색소를 이용하였으나, 낮은 내후성 및 내구성과 천연진주의 고급스러운 광택 표현의 어려움으로 인해 새로운 코팅기술이 필요한 실정이다. 본 연구는 코팅 결합제로 니트로셀룰로오스와 우레탄을 이용하였고, 색감을 표현하기 위하여 무기 펄 안료를 사용하였다. 니트로셀룰로오스와 용매의 비, 우레탄과 경화제의 비, 펄의 첨가량, 코팅 횟수, 건조 온도 등의 실험변수를 조절하여 실험을 진행하였다. 코팅 된 인조진주는 색차계, 자외선, 촉진내후성 등의 특성을 분석하였고, 우레탄을 이용한 경우 내약품성 및 내후성이 니트로셀룰로오스 보다 뛰어난 것을 확인하였다.

• 펄프종이기술
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• 제44권3호
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• pp.1-8
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• 2012

The effects of several factors including organic pigment blending and calending conditions on the surface and optical properties of coated paper were investigated. When clay and calcium carbonate are blended in the ratio of 7 to 3, highest smoothness and relative sediment volume were obtained. When organic pigments were added to the mixture of clay and calcium carbonate, the relative sediment volume did not changed significantly. However, when organic pigments were added to calcium carbonate, sheet gloss and smoothness were improved, and showed the better results than that obtained from the mixture of organic pigment and clay. When organic pigment is blended with clay, the particles of organic pigment are buried in the packing structure of coating layer. However, the particle shape of calcium carbonate is quite different from that of clay, and the aspect ratio of calcium carbonate is similar to that of organic pigment. Thus organic pigment particles are not buried and improved effectively the physical characteristics of coating layer. When the hollow sphere pigment was blended, opacity and sheet gloss were improved significantly. Even though the coating color applied was reduced, the similar level of opacity was maintained. Also, if particle size and void volume are increased, gloss is improved, because coating layer is easily transformed in calendering. Therefore, even though lower pressure was applied during calendering, the smoothness of surface of coating layer was improved, and the decrease of void volume in coating layer was reduced, and the quality of coated sheet can be improved.

• 펄프종이기술
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• 제39권2호
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• pp.25-30
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• 2007

Recently the use of web offset printing has been increasing, which can provide high print speed, mass production, and high print quality. However, high speed web offset printing has frequently undergone a blistering problem when the printed paper passes through hot air dryers. Blistering occurs in the middle of the base paper or in the coating layer. This paper focused on the blistering occurring in the base paper. In order to elucidate the effect of pigment ratio on blistering, 6 types of coating color were prepared with varying GCC/clay ratios and printability and blistering were investigated focusing on structure changes in the coating layer. When the clay content in the coating layer was increased, surface roughness and surface strength were decreased and paper gloss was increased. In addition, it was found that the coating layer structure with high clay content, which contains lots of discontinuous pores, hindered water vapors to penetrate out and, as a result, blistering occurred.