• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.30 no.2
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• pp.62-73
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• 1998

The aim of this work was to investigate the effects of pigment composition on the calendering response and structure of the coated paper. Calendering response of the coated paper was determined from the gloss values of the uncalendered and calendered coated papers, and the relationship between gloss and coating structure was discussed. The surface and cross section of the coating layer was observed using a scanning electron microscope to examine the coating structure. Coating layers were hardened in epoxy resin and polished with carbimet paper disc for preparing SEM samples. Maximum calendering response was obtained for the coated paper prepared from 80pph of clay and 20pph of ground calcium carbonate (GCC) as pigments. Photomicrographs of the surface and cross section of the coating layer show that clay tends to form dense coating structure, while GCC tends to form bulky coating layer.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.2
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• pp.16-21
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• 2014

Characteristics of coating color penetration into paper were elucidated using various types of pulps and pigments. A commercial paper, KP and TMP handsheets were used for base paper. Clay and GCC were used as coating pigment. Laboratory rod draw down coater was used for coating application. Coating color penetration was evaluated by measuring the roughness of surface and back side of a coating layer. The results of coating roughness showed that clay was much better than GCC as a coating pigment. In case of pulp type, KP base paper was more effective than TMP base paper to reduce coating penetration.

• Journal of Conservation Science
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• v.35 no.5
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• pp.403-415
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• 2019

According to oral tradition, the King Sejo's palanquin is indeed the palanquin of King Sejo, the 7^th monarch of the Joseon dynasty who reigned from 1455 to 1468, which was left behind after visiting the Magoksa temple. The palanquin is painted in five colors, mainly black, white, yellow, red and green. The chromaticity measurement of the yellow pigment showed that orpiment and gold are a noticeable distinction between the lightness and b^⁎ values. In the case of the red pigment, a^⁎ values of areas painted with cinnabar tend to measure at high values. As a result of the optical microscopy, scanning electron microscopy and energy dispersive spectroscopy analyses, it was determined that Chinese ink was used for the black pigment, lead white and white clay were used for the white, and orpiment and gold for the yellow. The red pigment was found to be the result of minium, cinnabar and red ocher, atacamite was used as green pigment. Though the analysis results of the cross sections on very small exfoliation fragments of pigments, it was confirmed that white clay and lead white were used for the preparation layer. In addition, several coloration techniques were considered based on these analyses.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.04a
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• pp.1-6
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• 1999

A study was made to determine the effect of plastic pigment on the coating structure and printability of coated paper. Three basic plastic pigments were investigated such as solid-bead type of plastic pigment, binder type of plastic pigment and hollow type of plastic pigment. In the systems investigated, it was observed that particle shape and structure of plastic pigment had influenced on the rheology of coating color, the state of packing, and the properties of coated paper. The materials investigated were restricted to plastic pigments commonly uesd in paper coating formualtion. Inorganic pigments used in this research were kaolin clay which is platelets and calcium carbonate which is rhombic. Three kinds of plastic pigments were blended in the color made up with two inorganic pigments, respectively. The combination of pigments were carried out (1) to determined the effect of paticle structure of plastic pigment on the state of dispersion of coating color, (2) to observe the effect of temperature of calender on the property of coated paper prepared with plastic pigment. The data indicated that binder and hollow type of plastic pigment had the best results on improving the properties of coated paper such as paper gloss, opacity and air permeability ect. and solid-bead type of plastic pigment in the next place.

• Journal of Conservation Science
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• v.35 no.6
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• pp.600-611
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• 2019

Yellow to reddish brown soil is generally referred to as hwangto and is used in various industries in Korea. Despite the fact that it is used as an inorganic pigment in dancheong, limited studies have been conducted on the properties of pigments associated with soil and on the mineralogical characteristics of hwangto. This study examines how the pedological and mineralogical features of hwangto affect pigment properties. Results indicate that reddish and yellowish soils have differences in terms of soil texture, mineral composition, oil absorption and stability under light. Reddish soil is mostly found in clay regions, whereas Ulleungdo hwangto is found in loam regions. Yellowish soil is mostly present in the clay loam to loam zones. whereas Haenam hwangto exists in the sandy clay loam zone. As a result of a mineralogical analysis, reddish soil is classified into the feldspar group and clay soil. The major minerals in the yellowish soils are similar however these soils differ in terms of clay mineral compositions. results of the characteristics of pigments prepared by the traditional method revealed that the average particle size is in the range of 10-20 ㎛, reddish soil has an average of 20 ml/100 g higher oil absorption than yellowish soil. In addition, reddish soil is more susceptible to discoloration and deterioration under light than yellowish soil. This study confirms that the soil and mineral characteristics of hwangto affect the physical properties and stability of produced pigments. These result can be used as basic data in future studies natural inorganic pigments using hwangto.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.29 no.1
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• pp.26-35
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• 1997

A study was carried out to investigate such optical properties of coated papers as brightness, opacity and gloss affected by the coating pigment composition and coat weight using clay, ground calcium carbonate, precipitated calcium carbonate, and plastic pigment as pigments. The effects of drying methods and supercalendering on optical properties were also evaluated. Gloss increased abruptly while brightness and opacity decreased slightly by supercalendering due to surface smoothing and consolidating effects of the coating layers. Optical properties changed little by drying methods. Pigment composition showed significant influences on optical properties. Brightness of coated papers decreased or increased linearly as the coat weight was increased depending on the pigment composition, while opacity increased linearly for all formulations. Gloss increased abruptly at low coat weights for all formulations and approached a plateau value at coat weight of 15-20g/$m^2$. Third order polynomial regression equations relating the coat weight with gloss have been derived and tabulated.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.3
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• pp.32-38
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• 2000

This study was carried out to determine the effect of the type of plastic pigment on the coat-ing structure and printability of coated paper. Three kinds of plastic pigments(solid-bead type binder type and hollow type) were used for hti purpose. IN this research it was observed that particle shape and structure of plastic pigment had influenced the rheology of coating color the state of packing and the properties of coated paper. Inorganic pigments used in this research were platelike kaolin clay and rhombic calcium carbonate. Three kinds of plastic pigments were blended with two inorganic pigments respec-tively. The combination of pigments were carried out(1) to determined the effect of particle structure of plastic pigment on the state of dispersion of coating color(2) to observe the effect of calendering temperature on the property of coated paper prepared with different plastic pigments. The data indicated that binder and hollow type plastic pigment gave the best results in improving the properties of coated paper such as paper gloss opacity and air pet-meability.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.4
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• pp.41-48
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• 2000

The main objective of this study was to investigate the packing state and optical properties of coated paper prepared with different coating colors by varying the blending ratio of such pigment as clay, $CaCO_3$, and plastic pigment. To evaluate the effect of packing state of pigment on the properties of coated paper, the coating thickness, which was theoretically calculated by specific gravity, and packing volume of pigment were used. It was found that there exists close relationship between the coating thickness and surface property of coated paper. For instance, the macro roughness(smoothness) of coated paper is closely related to bulkiness. Plastic pigments used in this research has a high finishing efficiency on the light weight coatings. Especially, hollow sphere pigment was very effective for improving the property of coated paper produced in this test. And when HSP was blended with $CaCO_3$the surface property such as smoothness and gloss improved significantly.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.48 no.2
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• pp.61-67
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• 2016

This study was carried out in order to investigate the effect of pigment properties in a pre-coating layer on the characteristics of a top-coating layer and the print mottle of the coated paper. Five different pigments were applied for this study as raw materials for the pre-coating layer. The properties and print mottle of the coated paper samples were evaluated according to the coating color formulation. Type of pigments appliied in a pre-coating layer was one of the most important factor to control the properties of pre and top coating layer. Surface properties of pre and top coated paper were improved by blending GCC which had smaller particle size, with clay. Properties of a top-coating layer was affected by the pigment properties used in the pre-coating layer. It was found that print mottle of coated paper can be improved by replacing part of GCC with smaller particle size GCC or clay in pre-coating layer.

• Journal of the Korean Wood Science and Technology
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• v.22 no.1
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• pp.85-90
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• 1994

The flow properties of binder latices for paper coating were investigated, together with dynamic viscoelastic properties of latex films and electron micrographs of latices, under various conditions. The amphoteric latex, binder pigment latex and anionic latex were used in this work. The amphoteric latex has both anionic and cationic functional group on its surface. The binder-pigment with a core-shell structure has dual functions : plastic pigment and binder. The low shear viscosity of binder latices and clay slurry were measured with Brookfield vis cometer. At low-shear rates. the viscosity decreased with increasing particle size of latex. On the amphoteric latex surface, the carboxyl groups are assumed to be fully dissociated over the region of pH 9~12, but the density of negative groups seems to be increased because of the gradual decrease in the degree of dissociation of amino groups. Since the apparent particle size of latex increases with surface charge, the electroviscous effect can be observed. On the anionic latex surface, the charge density is assumed to be nearly constant above pH 8. However, below pH 8 the coagulation of particles could be observed probably because of the decrease in the charge density.