• Journal of the Korean Wood Science and Technology
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• v.26 no.1
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• pp.7-13
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• 1998

In order to reconstruct the traditional technology of Korean golden varnish(Hwangchil) made from the exudates of D. morbifera, this study in the second step was carried out to analyze the chemical composition and oil properties of the exudates for coatings and bark extractives made from the trees of D. morbifera more than 20 years old grown in Wando and Jejudo islands in the southwestern part of Korean peninsula according to the physiological seasons. The results obtained are as follows: 1. The exudates appeared to be a phytoalexin because it exudated after several days in tapping only in summer season. 2. Both the exudates and bark-extracts with acetone contained 50~60% unsaponifiables and 30~50% saponifiables 3. A major component of essential oil in bark-extractives was ${\beta}$-cubebene and reached to 60~80%, while that of exudates included only 34% ${\beta}$-cubebene and some other compounds such as ${\beta}$-cadinene of 12%, aromadendrene of 9%, ${\beta}$-selinene of 9%, CAS030021-74-0 of 10%, etc. in GC-MS spectrometer. 4. A mjor component of fatty oil fraction in bark-extractives was linoleic acid and reached to more than 60%, while the exudates had mostly other components such as terpenes and phenolics instead of fatty acids accordint to GC-MS spectrometer. 5. Iodine value of samples after oil refining had 214mg/g in the exudates and more than than 150mg/g in bark-extractives, so the latter belonged to a drying oil.. 6. Therefore, the exudates from D. morbifera for traditional Korean golden varnish seems to have beeen used to a good varnish because it has some specific compounds different from its bark-extractives or general varnishes.

• Journal of the Korean Wood Science and Technology
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• v.26 no.3
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• pp.73-80
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• 1998

In order to reconstruct the traditional technology of Korean golden varnish coatings, this study was carried out to separate and determine some main coloring components of the exudates of D. morbifera and its traditionally refined golden varnishes using a process of solvent extractions, chromatographies and spectrometries. The results obtained are as follows: 1. The exudate and its traditional-refined golden varnishes appear to have a kind of natural polyacetylenes because it has some triple bond peaks in FT-IR spectrometry. 2. Some yellowing spots of the polar-solvent extrats from the exudates and refined varnishes separated on TLC appeared under natural drying condition, but those of non-polar solvent extract such as hexane did not. 3. A traditional refining method for reconstructing a Korea golden varnishes was thought to be better than solvent separation because the former had higher triple-bond peaks than the latter in FT-IR spectrometry. 4. One of main conponents in the hexane-extracts of the traditional-refined varnishes and the exudates had the same molcular weighr of 204, but the fragmentation patterns was a little different between the exudate and the refined. in LC-MS soectrometry.

• Journal of the Korean Wood Science and Technology
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• v.25 no.3
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• pp.24-28
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• 1997

As a way to revive the traditional technology of Korean golden varnish(Hwangchill), the exudates of D. morbifera, this study was carried out at first to investigate the anatomical characteristics and the chemical composition of D. morbifera stems and their exudates. Trees of more than 20 years old were harvested at Wando and Jejudo islands in the southwestern part of Korean peninsula during different physiological seasons of winter, spring, and summer, The results obtained are as follows: 1. In the anatomical aspect of wood, Hwangchil woods is ring-porous wood, has alternate inter-vessel pittings and horizontal intercellular canal in xylem. 2. In the chemical aspect of wood and bark, the general compositions appeared hot to differ from those of other hardwoods, and ash and alcohol-benzene extractives showed little increase with the increase of atmospheric temperature of harvesting season. 3. In the solvent-sequential extraction of bark, wood and exudate, the exudates was extracted up to 80% by ether, but the bark and wood contained a very small amount of ether extractives, about 2% in the bark and 0.5% in the xylem.

• Journal of Korean Society of Forest Science
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• v.87 no.2
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• pp.253-259
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• 1998

The stimulated secretion of golden varnish sap by the infection of microorganisms on the bark of Dendropanax morbifera Lev. was observed in the natural habitats. Four candidate strains of such microorganisms(i.e., Sb1, Sb2, Sb3 and Sb4) were isolated from the bark of D. morbifera which was infected in natural. Of them, Sb3 and Sb4 strains showed stimulated secretion of golden vernish sap with the greatest stimulation by Sb4 strains. The yield of golden varnish sap from the bark of D. morbifera was boosted about 3.4~7.7 times by the inoculation of Sb4 strain in compassion with that collected from lacquer tree(Rhus verniciflua Stokes) by the traditional method. The mycelium color of Sb4 strain was grayish white. The optimum growth temperatures and pH were ranged from 30 to $35^{\circ}C$ and from pH 6.5 to 7.0.

• Journal of the Korean Wood Science and Technology
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• v.38 no.4
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• pp.333-340
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• 2010

The Korean Dendropanax lacquer, made from a natural resinous sap from Dendropanax orbifera Lev., was used as a golden and transparent varnish for the traditional artifacts (armor uits, helmets, arrowheads, etc.) to make them be brilliant golden color. The cured film of the acquer has excellent protective properties such as weatherability, water resistance, and nticorrosive. But, one of disadvantages is that takes a long time and much energy to fulfill curing the lacquer. The chemical constituents of the lacquer contained conjugated diene compounds s the photopolymerizable monomers. These monomers easily polymerized in sunlight to form olden-colored, hard-coating films in a short time. Photooxidation may be one of the most mportant reactions in the chemistry of the lacquer. Although the Korean Dendropanax Lacquer hould be dried to a thoroughly dry stage to achieve optimal film properties, curing with elevated emperatures may be required for the protracted curing time at atmospheric temperature. So we ntended to accelerate the curing rate of the lacquer by dual curing of thermal and radiation uring. The effect of thermal initiator on the thermal curing reaction was evaluated by monitoring he changes in double bond peak with FT-IR. Then the curing rate of the lacquer blended with hermal initiator and photoinitiator together was measured during dual curing using a RPT with V spot curing machine. Thermal initiator not only accelerated the curing rate but also improved he physical property. And the curing rate of the Korean Dendropanax lacquer was improved by ual curing method of thermal and UV curing. According to these results, the application area of he Korean Dendropanax lacquer could be expanded to surface coatings for electronic devices uch as mobile phones or electronics.