• Korean Journal of Heritage: History & Science
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• v.42 no.3
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• pp.176-191
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• 2009

This report is a result of investigating the materials and techniques of the lacquer ware excavated from Hwangnamdaechong Tomb known as an old tomb in the Gyeongju maximum district. First, the fragment of lacquer ware was classified by the shape of it. Next, the thin section of lacquer film (all sides about 2mm) was made based on the result. Then they were observed under the microscope, and classified the kind of the foundation mixture and the applied structure. It is a result as follows. 1 The bone dust was mixed by the foundation of the made of cloth-body lacquer ware such as eared lacquer cup, lacquer bowl, and the lacquer rectangular containers excavated from the south tomb. 2 Eared lacquer cup and lacquer bowl, and rectangular box excavated from south and north tomb had the possibility they were the set of articles partially of tableware and the cosmetic box. 3 There is a difference in the quality of burial lacquer ware between in south tomb and north tomb. A lot of highlevel lacquer ware such as eared lacquer cup, lacquer bowl and the rectangular lacquer containers were discovered from the south tomb. 4 Many of containers where animal and bird had been drawn on the black lacquered ground excavated from north tomb were wooden bath.

• Korean Journal of Plant Resources
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• v.18 no.2
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• pp.279-284
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• 2005

The study was conducted to investigate the correlation and regression analysis between the factors - diameter, hight and crown width - and collection amount of Rhus lacquer by the sex of Rhus verniciflua. The relationship between the diameter and the collection amount of the lacquer by the sex of the lacquer tree indicated that, for both of the male and the female, the lacquer amount was likely to increase as the diameter got larger. In general, the male trees tended towards the higher amount of the lacquer than the female. The relationship between the crown width and the collection amount of the lacquer by the sex showed little difference. As the crown became wider, however, the lacquer amount showed the increasing trend. The regression analysis by the sex of the tree indicated that the major factors of the female had larger influence on the lacquer amount than those of the male. The no differences of statistical significance were found among the diameter, the height, the crown width, and the lacquer amount.

• Korean Journal of Heritage: History & Science
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• v.49 no.4
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• pp.114-125
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• 2016

Lacquer is one of the most widely used natural resin in East Asia since Neolithic Age. As a major ingredient of lacquerware, lacquer is waterproof, insect-proof and rot-proof to be durable and anti-abrasion, generally utilized for mainly painting purpose. According to lacquerware excavated from several sites of Japan and China, lacquerware seems to appear in Neolithic Age. On the other hand in case of excavation research in Korea, lacquerwares are found after the Bronze Age. The initial purpose of lacquer is estimated to be adhesive, regarding the literatures mentioning bitumen(Yeoksceong ), animal glue(Kyeo) and egg alumen(Nanbaek). Especially piece of jar coffin unearthed in Pyeongtaek Daechu-ri site had trace of restoration by lacquer and hemp as an evidence of lacquer for adhesion in Pre-Three Kingdoms period. Since then a trend to restore the broken ceramics with lacquer and decorate with golden foil lasted especially in Joseon Dynasty. In the field of gold plated lacquer method, mother-of-pearl inlaying technique for lacquerware and restoration of buildings, lacquer is still used as adhesive. Due to matter of reversibility lacquer is being avoided for conservation and restoration of cultural heritage. Lacquer as a traditional material for adhesive since ancient times, however, has advantage in adhesion strength and durability. Because synthetic resin adhesive has problem of emission of volatile organic compounds and aging over time, lacquer receives attention recently. On the contrary, by combination adhesive from mixing lacquer and animal glue, already proved the possibility of applicability and chemical modification. A research to utilize lacquer as modern paint or functional material is also conducted continuously also in China and Japan. To put traditional material into practical use and modernize, chemical research from the molecular level of the lacquer is necessary in the near future.

• Journal of the Korean Wood Science and Technology
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• v.31 no.4
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• pp.81-90
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• 2003

In this study, we investigated the weathering properties of Korean Rhus lacquers containing tung oil and their potential use as exterior coatings. The finished lacquers were prepared with a raw Korean Rhus lacquer or refined Korean Rhus lacquer content of 10, 20, 30 and 40 wt.% (corresponding to ratios of 10/90, 20/80, 30/70 and 40/60 by weight of Korean Rhus lacquer/tung oil, respectively). The curing temperature of the prepared lacquer increased with increasing the content of the raw Korean Rhus lacquer. This increased curing temperature is related to higher proportion of hydroxyl groups in the prepared lacquer, due to the content of the raw Korean Rhus lacquer. In accelerated weathering testing, the changes in the gloss and contact angle of the prepared lacquers showed a similar trend to that of traditional exterior oil stain. In addition, the prepared lacquers containing tung oil showed greater discoloration than traditional exterior oil stain. However, the discoloration of the prepared lacquer with a raw Korean Rhus lacquer content of 40 wt.%, and that of the prepared lacquer with refined Korean Rhus lacquer contents of 30 wt.% and 40 wt.%, showed a similar trend to that of traditional exterior oil stain. Consequentially, these prepared lacquers showed a potential for being used as exterior coatings.

• Food Science of Animal Resources
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• v.30 no.4
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• pp.597-602
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• 2010

In this study, pigs [n=117; (Landrace ${\times}$ Yorkshire) ${\times}$ Duroc; $64{\pm}0.5$ Kg initial body weight] were used to investigate the effect of feeding different levels of lacquer (Rhus verniciflua Stokes) meal on performance, carcass traits and quality of meat kept under refrigeration at $3{\pm}1^{\circ}C$. The pigs were randomly allotted to 3 treatments on the basis of body weight and sex and each treatment was replicated 3 times (13 pigs in each replicate). Lacquer meal in sawdust form obtained from the stem bark and heartwood of sun-dried lacquer trees was added to the grower and finisher diets at 0, 20 and 40 g/kg diet. The experimental diets were fed for 8 wk. Inclusion of lacquer meal had no influence (p>0.05) on growth performance of pigs. Improvement in carcass traits and decreased back fat thickness were noticed in pigs fed diets added with 20 and 40 g/kg lacquer meal. Longissimus muscle obtained from pigs fed lacquer meal had higher moisture and lower fat content, thiobarbituric acid reactive substances and water holding capacity. Meat from lacquer fed pigs was also darker and redder. The data indicates that lacquer meal can be incorporated up to 40 g/kg in the diet of fattening pigs without affecting growth performance. Also, lacquer meal increases carcass lean content and improves the oxidative stability of the meat.

• Journal of Conservation Science
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• v.37 no.3
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• pp.302-311
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• 2021

This study uses traditional lacquer techniques to coat the metal surface and evaluates its physical properties to check the applicability of the lacquer coating. For this purpose, a total of six specimens were produced by setting the variation conditions for the number of times (1, 2, 3) and the heating temperature (120℃, 150℃) using SS275 metal(60*60 mm) and 'Wonju lacquer'. For analysis, chromaticity measurements, contact angle/surface energy measurements, Chemical Resistance, and cross-cut tests were used. The analysis showed that the corrosivity was improved and the adhesion of lacquer to the metal surface was excellent. There was no significant change in contact angle/surface energy. Also, there was no significant difference in color. Through this study, it was confirmed that lacquer on metal surfaces improves waterproofing and has a anticorrosion effect. We could also check the proper number of lacquer and heating temperature. Additional physical characteristics such as hardness and wear rate should be studied. It is also necessary to study how lacquer can be painted with a certain thickness.

• Journal of the Korean Wood Science and Technology
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• v.36 no.6
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• pp.105-112
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• 2008

Grading of the urushi lacquer is quite difficult because of large variations depending on origin, growing conditions, time acquisition, storage conditions. It is urgently required to establish a grading system of urushi lacquer by combining traditional method with scientific methods. Traditional grading of urushi lacquer was done by visual inspection of 10 experts who are working on urushi lacquer industry. Common aspects of the experts were color, odor, viscosity, spread properties on Hanji, color and drying properties on glass based the traditional grading system. In addition, rubbing on Hannj and heating with alcohol lamp was also used to grade urushi lacquer. The grading results of 10 experts showed that chinese urushi lacquer (E) of 7.03, japanese urushi lacquer (C) of 6.84, domestic urushi lacquer of (A) of 6.41 and another chinese urushi lacquer (D) of 5.27, and domestic urushi lacquer (B) of 2.50 in descending order. The degree of spread on Hanji was not consistent among 10 experts. These results indicated that the traditional grading system was pretty much personal and required of developing more objective method based on scientific background.

• Korean Journal of Food Science and Technology
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• v.49 no.4
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• pp.415-420
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• 2017

Soybean sprouts are the third-most consumed vegetable in Korea. Several studies on cultivation techniques, including use of medicinal plants extracts, have been performed to enhance the quality and yield of soybean sprouts. The objective of the present study was to investigate the effect of lacquer, a medicinal plant extract, on the yield and nutritional value of soybean sprouts. Linolenic acid content was significantly (p<0.05) increased in the sprouts produced by soaking seeds in lacquer extract diluted with equal volume of water. Lacquer extract significantly increased the flavonoid and phenolic contents (p<0.05). The content of total free amino acids, including ${\gamma}$-aminobutyric acid, was higher in lacquer extract-treated sprouts than in the untreated control. Results of this study suggest that lacquer extract could be used for enhancing the yield and nutritional values of soybean sprouts.

• Journal of the Korean Wood Science and Technology
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• v.46 no.1
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• pp.1-9
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• 2018

Nowadays, synthetic resin varnish such as cashew nut shell liquid (CNSL) is being used as well as traditional lacquer. The code of ethics states that material must be identical to the original when preserving cultural heritage. Therefore, lacquer should be used. However, problem is that even experts have difficulties differentiating lacquer and CNSL as they have similar components. Therefore, this study was carried out to identify the difference between lacquer and CNSL using IR and Py-GC/MS. As a result of IR, in lacquer, $720cm^{-1}$ peak was detected and in CNSL, $750cm^{-1}$, $720cm^{-1}$ and $700cm^{-1}$ peaks were detected. The results of Py-GC/MS detect benzene compounds and alkyl chains for both varnishes. However, hexanoic acid was detected from CNSL but not lacquer. Using these analytical methods, the differences between lacquer and CNSL can be identified on the scene. This is expected to be applied to the authentic conservation and restoration of lacquerware.

• Tribology and Lubricants
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• v.31 no.3
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• pp.86-94
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• 2015

We perform lacquer formation experiments with various combinations of marine fuel oils and lubricant oils. We also investigate the influences of base number (BN) in lubricant oil and sulfur content in fuel oil. A dissolution test with 10% dilute sulfuric acid and pull-off force test are accomplished to distinguish whether the residual layers are lacquering or not. The lacquering layers are dissolved by dilute sulfuric acid and have a strong pull-off force. Moreover, the calcium content detected in the residual layers is compared by energy dispersive x-ray spectroscopy (EDS). More calcium is detected in the lacquer layers than in other residual layers. Distillate fuels containing low sulfur levels are more prone to lacquering when mixed with lubricant oil with a high BN. On the other hand, residual fuels with a high sulfur content do not form lacquer. We investigate the effect of mixture volume ratio. The mixture with higher fuel oil content is more prone to generate lacquer. These experiments indicate that a lubricant with an appropriate BN should be used to prevent lacquer forming on the surfaces such as cylinder liners depending on the sulfur content of fuel oil.