• Conservation Science in Museum
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• v.10
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• pp.43-61
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• 2009

The Buyeo National Museum was requested conservation treatment for wooden objects excavated from three Baekje archeological sites: Neungsan-ri, Ssangbuk-ri, and Gungnamji Pond. Prior to conservation treatment, analysis was conducted to identify the species used. The results of the analysis revealed wood from diverse species of trees including Hard pine, Cryptomeria japonica D. Don, Zelkova serrata Makino, Quercus spp., Platycarya strobilaceae S. et Z., Castanea spp., Torreya nucifera S. et Z., Taxus cuspidata S. et Z., and Salix spp. A high percentage of the objects were made of Cryptomeria japonica D. Don., a species native to Japan, which indicates that exchange with Japan was active at that time. Among the wooden objects, we analyzed lacquer fragments from six pieces of lacquerware, and the characteristics of the lacquer fragments were peculiar to specific artifacts. Most of the fragments were thicker than 100 ㎛. Pure lacquer and mixed black pigment were used. Infrared spectroscopy of the lacquered wooden fragments revealed that they had a very similar absorption band as refined lacquer, confirming that they were painted with lacquer. For their conservation, we immersed the objects in a high molecular weight aqueous solution of PEG#3,350 (10% → 50%) to strengthen them before vacuum freeze-drying.

• Korean Journal of Plant Resources
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• v.13 no.1
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• pp.48-53
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• 2000

Lacquer tree can be proliferated by root or stem cutting, and seed. In case of proliferation by seed, however, the germination rate is very low. Thus, the present study was carried out to obtain aspceptic lacquer plant in vitro from seed because natural tissue culture was highly defiled by unknown fungi and bacteria. First seed grading on distilled water was 50.7% and second seed grading was 20.8% after 98% sulfuric acid treatment for 2 hours. Removal of inner seed coat was higher with 32.4% than non-removal of outer seed coat and removal outer seed coat in rooting rate. In germination rate according to pre-treatment, growth regulators were not effective at all, but sulfuric acid was effective a little with 3%. Removal outer seed coat was increased about 4%, that germinated about 10% in MS medium supplemented with 1.0mg/L BA and 0.05mg/L NAA, 1.0mg/L BA. Lacquer tree seeds germinated after 10 days in MS medium, and aspceptic seedling of lacquer tree were obtained after 3 weeks in vitro. Germination rate, however, was lower about 10%.

• Journal of the Korean Wood Science and Technology
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• v.48 no.3
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• pp.326-344
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• 2020

Laccase was applied to improve the drying speed of urushi lacquer to confirm a potential use of laccase as an enzyme additive. As a result of applying laccase of lacquer and white-rot fungi, drying times for both Korean and Chinese specimens were reduced. All of the specimens to which laccase was applied were dried(set to touch) within 60 minutes from the start of the drying, and the drying rate was improved as the content ratio of laccase increased. In addition, although there were differences in hardening drying time between Korean and Chinese lacquers, it was confirmed that hardening drying took place even at room with temperature of 20 ± 2 ℃ and humidity of 55-60%. As a result of lacquer layer analysis of the dried specimens, the drying speed was improved when the content ratio of laccase to urushiol was 5:1, and there were no differences in chromaticity and adhesion, confirmed that the layers were stable. It was observed that the gloss of both Korean and Chinese lacquers were reduced when laccase was applied. However, according to the analysis of FT-IR and Py-GC/MS, the changes in components were not as sufficient to affect the physical properties. Thus, its applicability as an additive was confirmed.

• Journal of the Korean Wood Science and Technology
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• v.35 no.6
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• pp.65-72
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• 2007

The VOC (volatile organic compound) analyzer is devised to measure the four main aromatic hydrocarbon gases: toluene, ethylbenzene, xylene and styfene. It is not affected by ambient temperature and humidity. In addition, standby and measuring time of VOC Analyzer is a short as below 30 min and 8 min, respectively. Since the semiconductor gas sensor is supersensitive to gas components, it is not necessary to use a conventional gas concentrator or other complicated equipment. In this study, VOC emission behavior from 4 types paints (lacquer, urethane vanish, water-base paint, enamel paint) for wood-based panel was investigated using VOC Analyzer. After a specimen was spreaded on aluminum foil ($6.32{\times}6.32cm$) in $3{\ell}$ polyester bag, after 24 hours we could measure maximum VOC emission level that is a stabilized VOC value. Xylene of VOCs was high emitted from lacquer, urethane vanish and water-based paint, and TVOC (Toluene + Ethylbenzene + Xylene + Styrene) of lacquer was the highest emission concentration than another.

• Korean Journal of Plant Resources
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• v.18 no.2
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• pp.337-342
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• 2005

This study was conducted to investigate the bark production from a top branch(Woojuk) of lacquer tree(Rhus verniciflua) that collected Rhus lacquer in summer, analyzing a relationship between several factors - diameter, tree weight, weight of Woojuk and bark. The weight of Woojuk averaged was made up $48\%$ of the tree on average. As the weight of the tree increased, however, the Woojuk showed the rising trend. It was turned out that the tree size for making 1kg of dry bark must be at least DBB 8cm. The result on Woojuk's bark was that $43.3\%$ of total trees produced a green bark of 1.1kg to 1.5kg, and most of them put out 1.5kg and less. Also the rate of trees to make 0.6kg to 1.0kg of dry bark was highest in $50.8\%$, but its production in most trees was 1.0kg and below. As the moisture content of a green bark averaged $39\%$, it is estimated that the production of 1kg in dry bark requires at least 6kg of top branch in lacquer tree.

• Journal of Conservation Science
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• v.37 no.3
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• pp.245-254
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• 2021

In this study, organic materials in Dancheong specimens were analyzed to establish a Dancheong preparation method in Unhangak Hall of Hwaryeongjeon Shrine, Suwon. IR and pyrolysis/GC/MS were applied to a Zuhong specimen and a gilded one. The IR spectra showed absorption peaks corresponding to C-O, C=O, OH, although they were different from those of animal glue, Asian lacquer, and drying oil. The Pyrolysis/GC/MS after the on-line methylation revealed Asian lacquer-derived components, such as methyl 7-(2,3-dimethoxyphenyl)heptanoate, and drying oil-derived components, such as nonanedioic acid, dimethyl ester. Based on these results, we estimated that Asian lacquer and drying oil were used in the Dancheong preparation. Small amounts of 3-methyl-1H-pyrrole were also detected, which could possibly originate from animal glue. The radiocarbon age of the specimens appeared to be between the late 17^th to the early 20^th century. This study potentially reports the first case of Asian lacquer detection in a Dancheong specimen in Korea.

• Journal of Conservation Science
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• v.37 no.2
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• pp.77-89
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• 2021

In this study, materials and color formation techniques were assessed for black potteries excavated from the Janghyeon-dong, Jungsan-dong and Gyodong-ri sites during the Proto-Three Kingdoms period in Ulsan, Korea. Although the black potteries were black superficially, the inner cores were either black or reddish yellow. Microscopy analysis identified that body clay was used for reddish iron oxide rich soils with quartz, alkali feldspar and mica, along with grains of myrmechite texture. Additionally, as marginal differences exist in the contents of SiO₂, Fe₂O₃ and CaO, the composition of the host rock and clay distributed around the sites was affected. Thus, we can deduce that pottery was made by soiling at a short distance. Raman spectroscopy results revealed that the black layer of the black pottery was used as amorphous combustion carbon. In addition, as a transparent layer of brown lacquer was observed on the substrate that was in contact with the surface layer, the black layer of the pottery induced black color development by a combination of combustion carbon and lacquer. Based on the mineral composition and microtexture of the body clay, the firing temperature of the potteries seemed to range from 750 to 850℃, whereas the lacquer layer was pyrolyzed at 468℃ by thermal analysis. Therefore, a combined layer of combustion carbon and lacquer, which formed the black color, was painted after the body clay was fired.

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2003.10a
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• pp.152-154
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• 2003

• Journal of the Society of Cosmetic Scientists of Korea
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• v.5 no.1
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• pp.31-42
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• 1975

• The monthly packaging world
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• s.339
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• pp.68-72
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• 2021