Natural Lacquer Research Articles

Study on Properties of Silver Powder for Maki-e

Maki-e is a traditional Japanese decorative technique that uses the natural lacquer Urushi and metal powders. In 2014, there exist only two companies that manufacture silver powder for the purpose of Maki-e, and this study focuses on comparing the powders manufactured by them. Gloss and color of each silver powder were measured after Maki-e decoration was finished, and EDS (energy-dispersive X-ray spectroscopy) was used to determine the differences in their chemical composition. In addition, to verify the effect of polishing, residual gloss after sulfuration and polishing was measured. The study revealed that the shapes of the silver powders (Maru-fun, No. 1) manufactured by the two companies are different and it affects the occupancy rate of Urushi and powder, which in turn affects their gloss and color. Wakou silver has a very strong resistance to sulfuration; however, owing to its Pd content, its chroma is much lower than that of other powders. It was shown that sulfuration on powder surface can be removed by polishing irrespective of the shape and chemical composition ratio of the particles.

Study on Characteristics of Gold Powder with Round Shape for Maki-e

Maki-e is a traditional Japanese decorative technique that uses the natural lacquer Urushi and metal powders. Currently, there exist only two companies that manufacture metal powder for the purpose of Maki-e, and this research focuses on comparing the material characteristics of the gold powders with round shape manufactured by them. EDS (energy-dispersive X-ray spectroscopy) analysis, image analysis of particle shape before and after Maki-e processing, and color analysis of samples after Maki-e processing were carried out in this research. The study revealed that current gold powders with round shape had almost the same content ratio regardless of the manufacturing company and the powder diameter. In addition, spherical shape and irregular shape were observed in any gold powders, and the aggregates were observed in powder with increasing the powder diameter, while the shape of the aggregates differed with manufacturing companies. Therefore, it was indicated that the aggregates in the powder made by Asano Co., Ltd. had an influence on the particle diameter and its deviation after Maki-e processing. Moreover, the powder in Urushi resin has an influence on the Maki-e appearance because there is a color difference in polished powder, powder in Urushi resin, and Urushi resin.

Investigation of Ryukyu lacquerwares by pyrolysis-gas chromatography/mass spectrometry

Two pieces of lacquer obtained from Ryukyu lacquerwares produced in the 17–19th century in the Ryukyu Kingdom belonging to the Urasoe Art Museum were analyzed by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The results were compared with the standard of natural lacquer film to determine the identity of the lacquer species. Urushiol (MW=320), 3-heptylcatechol (MW=208), and 3-heptylphenol (MW=192) were detected as pyrolysis products of lacquer pieces of a lacquer tray made by the hakue technique, suggesting that this Ryukyu lacquerware was coated with lacquer sap tapped from a Toxicodendron vernicifluum lacquer tree. On the other hand, urushiol (MW=320), 3-heptylcatechol (MW=208), 3-heptylphenol (MW=192), laccol (MW=348), 3-nonylcatechol (MW=236), and 3-nonylphenol (MW=220) were detected as pyrolysis products of lacquer pieces from a dinner tray made by the mitsuda-e technique, suggesting that this Ryukyu lacquerware was coated with mixture lacquer sap tapped from T. vernicifluum and Toxicodendron succedanea lacquer trees, respectively. Moreover, microscopy and cross-section studies demonstrated that the lacquers had a multi-layer structure. X-ray analytical microscopy was carried out directly on the surface of lacquerwares to determine the presence of different pigments.

Preparation and the antioxidant and antibacterial activities of urushiol powders (YPUOH)

Abstract Lacquer sap derived from lacquer trees has been widely used in Asian countries for thousands of years as a natural paint and coating material. These natural lacquers exhibit superior barrier properties against oxygen and water, as well as good durability, chemical resistance, mechanical properties, and antibacterial and antioxidant properties. However, they are limited in commercial application due to their high volatility, low drying rate, and allergic reactions. To overcome these limitations, powder-type urushiols (YPUOH), which are essential to provide convenient handling, were successfully prepared using urushiol and different contents of 3-(trimethoxysilyl) propyl methacrylate (TPM). The prepared YPUOH powders were analyzed by Fourier-transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), thermogravimetric analyzer (TGA), and antibacterial and antioxidant measurements. The as-prepared YPUOH powders exhibited excellent antibacterial activity against E. coli and S. aureus , good antioxidant activity, and high thermal stability.

Application of Pyrolysis Gas Chromatography/Mass Spectrometry in Lacquer Research: A Review

Examination of thermal degradation of natural and synthetic lacquer films by pyrolysis-gas chromatography with mass spectrometry (Py-GC/MS) is reviewed. Due to the instantaneous heating decomposition, side reactions of internal or intermediate samples hardly occur, and the pyrolysis products can be retrieved without any change. Py-GC/MS has been used to analyze the composition of insoluble polymers and investigate degradation of resin materials. Lacquer film is a cross-linked polymer that is insoluble in any solvent. The aim of this review is to describe the application of Py-GC/MS to the analysis of lacquer, including natural lacquer saps, synthetic lacquer derivatives, and their films. After analyzing the chemical structures of the specific pyrolysis products by mass spectrometry, the lacquer tree species and growing region can be determined. These results have great significance for the protection and restoration of lacquer-coated cultural treasures.

Study on the Appearance and Peel Strength of Byakudan-Nuri Works

This paper focuses on Byakudan-nuri, one of the traditional decoration techniques of Japanese Urushi (Urushi natural lacquer) crafts. Works produced by Byakudan-nuri express a unique luster color owing to painting gold or silver leaves along with highly transparent Urushi. The specific problem of Byakudan-nuri is the exfoliation of Urushi off the metal leaf surface, to solve a lot of repair work which is done nowadays. For Byakudan-nuri, silver leaf is preferred to a gold leaf. This paper tries to clarify the influence of the different kinds of metal leaves on the appearance and peel strength of works of Byakudan-nuri and, moreover, to elucidate the reason why silver leaf has been used more frequently for Byakudan-nuri until now. It was found out that the reason for the more frequent use of silver leaf in Byakudan-nuri is that silver does not seem to affect the appearance and peel strength in works produced by this technique.

Development of bio-based hybrid resin, from natural lacquer

Preparation and structure analysis of a bio-based hybrid material composed of natural lacquer, epoxy, and organic silane compounds were investigated using liquid and solid-state nuclear magnetic resonance. The good composition of additives in the hybrid was determined by the drying, hardness, and resin-molding properties. Although natural lacquer alone cannot form thick resins, this bio-based hybrid material showed good resin formation at room temperature without thermal treatment. This result could be based on the enhancement of curing by the sol–gel reaction between natural lacquer and the organic silane compound, and a crosslink reaction between organic silane and epoxy groups. At the same time, oxidative polymerization at the unsaturated side chains in the urushiol was enhanced by the sol–gel reaction because the catechol hydroxyl groups, which have an antioxidative property, reacted with the organic silane. In addition, this bio-based resin possesses a thermoset property because curing of the hybrid was improved by thermal treatment. Based on the structure analyses, the sol–gel reaction between urushiol and organic silane compound proceeded immediately, indicating the high reactivity of this sol–gel reaction. On the other hand, the reaction between bisphenol A-type epoxy resin and the organic silane seems to progress slowly after the epoxy ring opening. In addition, a sol–gel reaction occurred between the amine group in the organic silane and the hydroxyl group formed after the crosslink reaction of the epoxy group. These results suggested that the improvement in drying and molding properties of the hybrid was based on the chemical reactions among all components (i.e., natural lacquer, epoxy, and organic silane).

옻(Rhus verniciflua Stokes)으로 부터 분리한 알레르기 유발물질의 BALB/c mice에 대한 특성

옻 allergy 유발물질을 분리하고 그 특성을 연구하기 위하여 국내산, 중국산 및 일본산 생 옻을 사용하였다. 옻의 crude extracts로부터 crude urushiol을 정제하고, 다시 allergy 유발물질로 알려져 있는 3종의 urushiol congeners를 분리하였다. 분리한 urushiol congeners는 RV-1 였으며, 전체의 80%에 해당하였다. RV-1의 함량은 중국산에서 70.07%로 가장 많았으며, 일본산에서 62.38%로 가장 적었다. 반면에 RV-2는 일본산은 9.25%로서 국내산과 중국산의 4.28 및 3.09%에 비하여 약 2$\sim$3 배정도 많았다. Allergy 유발특성을 보면, RV-1은 초기유발강도가 강하고 지속적이어서 회복속도도 늦었다. RV-2는 초기유발강도는 약하지만 회복속도는 늦었다. 반면에 RV-3는 초기유발강도는 비교적 약했지만, 감작 후 48시간 째에 가장 강하게 유발되었고, 회복속도가 빨라서 72시간이 경과하였을 때에는 거의 대조군 수준으로 회복되었다. 따라서 allergy유발에 가장 큰 영향을 미치는 urushiol은 RV-1이었으며, RV-1의 함량이 가장 많은 중국산이allergy의 유발강도가 가장 강하였고 회복속도도 늦음을 알 수 있었다. We purified crude urushiol from natural lacquer produced in Korea, China, and Japan and then isolated several urushiol congeners known to induce allergic reactions. The 3 major kinds of urushiol congeners that were isolated and purified were RV-l (C<TEX>$_{21}$</TEX>H<TEX>$_{34}$</TEX>O<TEX>$_2$</TEX>, M.W. 314.462), RV-2 ((C<TEX>$_{21}$</TEX>H<TEX>$_{32}$</TEX>O<TEX>$_2$</TEX>, M.W. 316.240) and RV-3 ((C<TEX>$_{23}$</TEX>H<TEX>$_{34}$</TEX>O<TEX>$_2$</TEX>, M.W. 342.515), occupying 80% of total crude urushiol. The content of RV-l was the highest in natural lacquer from China at 70.07%, and was the lowest in that from Japan at 62.38%. However, the content of RV-2 in natural lacquer from Japan was 9.25%, 2<TEX>$\sim$</TEX>3 times higher than those from Korea (4.28%) and China (3.09%). As an allergy inducing character, RV-l had strong inducing power and durability in the primary stage, showing slow recovery. RV-2 had weak power in the primary stage and also showed slow recovery. Although RV-3 had comparatively weak power at the primary stage, it induced the strongest allergy contact dermatitis after 48 hr. However, it recovered to nearly the same level as control group 72 hr after sensitization time. Accordingly, we found out that RV-1 is the most influential of urushiol congeners in inducing allergic reactions, natural lacquer from China having the most inducible strength and slowest recovery compared to those from Korea and Japan.

Anti-biofouling behavior of natural unsaturated hydrocarbon phenols impregnated in PDMS matrix

Some species of natural unsaturated hydrocarbon phenols have been reported to have anti-biofouling effect. They have potential industrial applications where bacterial contamination should be avoided. We fabricated polydimethylsiloxane (PDMS) matrices impregnated with unsaturated hydrocarbon phenols: urushiol from the sap of natural lacquer tree and a mixture of cardol and cardanol from refined cashew nut shell liquid (CNSL). Their anti-fouling property has been tested by crystal violet staining method. Urushiol-impregnated PDMS matrix showed excellent antimicrobial property to both Escherichia coli and Saccharomyces cerevisiae. With the concentrations of cardanol higher than a certain critical value, CNSL-impregnated PDMS matrix also showed anti-biofouling effect for E. coli and S. cerevisiae.

A Study on Multi-Layered EM Wave Absorber Using Natural Lacquer as a Binder

Generally, a silicone rubber and a chlorinated polyethylene(CPE) have been used as a binder for the development of high-performance composite EM(Electro Magnetic) wave absorbers. In this paper, the EM wave absorption performance of natural lacquer, which is newly proposed as a binder was investigated. The prepared MnZn ferrite EM wave absorbers are mixed with natural lacquer showed excellent EM wave absorption characteristics compared with MnZn ferrite EM wave absorbers which are mixed with the conventional binders. MnZn ferrite EM wave absorbers mixed with natural lacquer were prepared and their absorption ability was also investigated The EM wave absorbers are fabricated in different proportions of MnZn, or NiZn ferrite and natural lacquer, and their reflection coefficients are measured. The permittivity and permeability are calculated by using the measured reflection coefficients. The EM wave absorption abilities are calculated according to different thicknesses of the EM wave absorbers.

Design and characterization of modified urethane lacquer coating

A new series of natural lacquer/polyurethane (LPU) blended films were synthesized. The new lacquer/polyurethane films have very good visual color and detected gloss, fast drying time, strong weather resistance, especially against UV light and water, and a better pencil lead hardness (8H). The gel ratio increases with drying time and becomes stable after 6 months (more than 99%). The surface glass transition temperature ( T gs) obtained from a rigid-body pendulum physical properties testing (RPT) instrument showed that the new LPU films dried for 6 months have higher T gs than polyurethane (PU) films in the following order: LPU 100 > LPU 90 > LPU 80 > LPU 70 > LPU 60 > LPU 50 > PU. Differential scanning calorimeter (DSC) results showed the same tendency as T g but without a great gap in the LPU series except for polyurethane. Thermogravimetric analysis (TGA) showed that when the ratio of natural lacquer is more than 50%, the 50% weight loss temperatures increase about 100 °C. In addition, the reaction between lacquer and polyurethane is discussed based on the IR and NMR measurements.

Synthesis of Rhus succedanea lacquer film and analysis by pyrolysis-gas chromatography/mass spectrometry

Laccol, a major component of lacquer sap from Rhus succedanea, was synthesized by a Witting reaction, and then mixed with acetone powder separated from raw lacquer sap to synthesize lacquer films. The resulting lacquer films were analyzed by pyrolysis gas chromatography/mass spectrometry (Py-GC/MS), and the results were compared with that of natural lacquer film to evaluate the polymerization mechanism and film structure. The results showed that saturated and monoenyl laccol components were present only in the natural lacquer film, but not in the synthesized lacquer films. Meanwhile, alkylphenols, alkebulphenols, alkanes, and alkenes having longer carbon chains than the side chains were detected in the synthesized laccol, suggesting that the polymerization of synthetic laccol proceeds through the laccase-catalyzed nucleus-side chain C O coupling and autoxidative side chain to side chain C C coupling like natural lacquer film. The synthesized laccol films showed shallow color and hardness, which would make them useful as good preservative surface-coating materials.

Applied analysis of lacquer films based on pyrolysis-gas chromatography/mass spectrometry

Ancient lacquer film, a Nanban lacquer film, an old lacquer-ware object imported from an Asian country, and the Baroque and Rococo lacquer films were analyzed by pyrolysis-gas chromatography/mass spectrometry. Compared with the results of the natural lacquer film, it was revealed that the ancient lacquer film and Nanban lacquer film were made from Rhus vernicifera, and the old lacquer-ware imported from an Asian country was made from Melanorrhoea usitata. However, the Baroque and Rococo lacquer films obtained from the Doerner Institute in Munich, Germany were made from natural resins. 3-Pentadecylcatechol (MW = 320) (urushiol), 3-heptadecylcatechol (MW = 348) (laccol), and 4-heptadecylcatechol (MW = 348) (thitsiol) were the main products of the pyrolysis of R. vernicifera, Rhus succedanea, and M. usitata.

Studies on a newly designed natural lacquer

A new natural lacquer was synthesized using a precious metal colloid and an organic silicone compound. The new lacquer had strong UV and water resistances. The viscosities were from 2000 to 6000 mPa s −1 at 20 °C, and the molecular distributions estimated by GPC were not significantly different, suggesting that the new lacquer hybridized with an organic silicone compound and a precious metal colloid was stable and suitable for use as a paint. In addition, the liquid and solid UV spectra of the new lacquer film showed almost the same absorption as the Au colloid alone at 523 nm, implying that the distribution of the precious metal colloid in the lacquer sap was homogeneous. The drying mechanism and other physical properties were also examined by RPT, DOI and DSC measurements.

옻의 특징과 옻을 지지재로 사용한 전자파 흡수체의 두께에 따른 전파흡순 특성 분석

Generally, a silicone rubber and a chloride polyethylene(CPE) have been used as a binder for high-performance composite EM( Electromagnetic) wave absorbers. In this study, the EM wave absorption abilities for natural lacquer which is newly suggested as a binder were investigated MnZn ferrite composite EM wave absorbers mixed with the natural lacquer were prepared and their absorption ability was also investigated. The prepared MnZn ferrite composite EM wave absorbers mixed with natural lacquer showed an improved EM wave absorption characteristics compared with MnZn ferrite EM wave absorbers mixed with the conventional binders. such as a silicone rubber and a chloride polyethylene(CPE). The matching frequency and the absorption ability of EM wave absorbers varied with the thickness of them.

NC와 옻칠을 소재로 한 고성능 전파흡수체에 관한 연구

천연세라믹, 옻칠, 그리고 고무의 전파흡수능을 조사하였다. 천연세라믹은 2.5GHz~4.5GHz의 주파수 범위에서 2.5dB이상의 전파흡수능을 나타내었으며 옻칠의 전파흡수능이 기존에 전파흡수체의 지지재로 이용되는 고무에 비해 우수한 전파흡수능을 갖고 있음을 확인하였다. 페라이트에 옻칠을 지지재로 이용한 전파흡수체에 대하여 시뮬레이션 한 결과 0.5GHz~10GHz의 주파수 범위에서 16dB 이상의 우수한 전파흡수능을 나타내었다. 따라서 기종에 지지재로 이용하던 고무대신 본 연구에서 새롭게 제안하는 옻칠을 전파흡수체의 지지재로 이용하는 것이 광대역에서 우수한 전파흡수체를 얻을 수 있을 것으로 예상된다. The electromagnetic wave absorption ability of natural ceramics(NC), natural lacquer, and rubber was investigated. The natural ceramics showed absorption ability above 2.5dB at 2.5GHz~4.5GHz and natural lacquer showed better electromagnetic wave absorption ability than that of rubber. The simulation results of electromagnetic wave absorber ability in a absorber composed of natural lacquer and ferrite showed the reflection coefficient of -16dB at 0.5GHz~10GHz. It was shown that from the simulation results, the electromagnetic wave absorber composed of lacquer as a backing material have better absorption ability than that of the electromagnetic absorber composed of rubber.

Chemical modification, characterization and structure-anticoagulant activity relationships of Chinese lacquer polysaccharides

A natural lacquer polysaccharide with complex branches was separated into two fractions, LPH (MW 16.9×10 4) and LPL (MW 6.85×10 4). Results of 13C NMR and FT-IR indicated they had the same structure. The treatment of LPL with sodium periodate led to a partial cut-off of side chains with 4- O-methyl-- d-glucuronic acid in the terminal. These polysaccharides were sulfated in the presence of Py·SO 3/DMSO. Depending on the reaction conditions, the products showed a different degree of sulfation (DS) ranging from 0.57 to 1.57 and different molecular weights ranging from 1.71×10 4 to 3.49×10 4. FT-IR analysis showed the equatorial primary OH at O-6 and the axial secondary OH at O-4 were sulfated. Activated partial thromboplastin time (APTT), prothrombin time and thrombin time (TT) assays showed the sulfated polysaccharides could prolong APTT and TT, but not TP. These activities strongly depended on the DS, the molecular weights (MW) and the branching structure of polysaccharides. DS of above 0.8 was essential for anticoagulant activity. The anticoagulant activity increased with the DS and the molecular weights. The molecular weights played a more important role. The branching structure of polysaccharides increased the activities. In our studies, the sulfated polysaccharides with the DS of 1.15 and the highest MW of 3.49×10 4 had the best blood anticoagulant activities.

Evaluation of Synthesized Lacquer Films Using Pyrolysis-Gas Chromatography/Mass Spectrometry

Abstract The trienyl urushiols, which are major urushiol components, were synthesized via the Wittig reaction. The synthesized urushiols were then polymerized into synthesized lacquer films by laccase-catalyzed oxidation. The resulting lacquer films were characterized using Pyrolysis-GC/MS, and the results were compared with that of a natural lacquer film in order to evaluate their polymerization mechanism and molecular structure. Based on these results, it was found that natural lacquer films are terminated with the monoenyl and saturated urushiol, and that the polymerization of synthesized urushiol proceeds through the laccase-catalyzed nucleus-side chain C-O coupling and autoxidative side chain-side chain C-C coupling, like the natural lacquer film.

Characterization of synthesized lacquer analogue films using x-ray photoelectron spectroscopy

Four kinds of synthesized lacquer analogue films were characterized using x-ray photoelectron spectroscopy (XPS) and the pencil hardness testing method. The results were compared with natural lacquer film. Laccase-catalysed oxidative polymerization and autoxidation have been found to contribute to the hardening of the synthesized lacquer analogue. Plant gum and glycoproteins are concentrated in the surface of the synthesized lacquer film during hardening, as with the natural lacquer films. Furthermore, synthesized urushiol analogues, in which side chains are richer in the double bond, polymerize into harder lacquer films and concentrate more oxygen and nitrogen in the film surface with proportionately more COO, CO, COC and CN functional groups. The synthesized lacquer films are brilliant and tough like the natural lacquer film. Copyright © 2000 John Wiley & Sons, Ltd.

Structural Studies and Polymerization Mechanisms of Synthesized Lacquer Films Using Two-stage Pyrolysis-Gas Chromatography/Mass Spectrometry

Two kinds of synthesized lacquer films were investigated and compared with a natural lacquer film using two-stage pyrolysis-gas chromatography mass spectrometry (Py-GC/MS). Monoenyl and saturated urushiol were detected from the synthesized lacquer film by pyroly-sis at 400°C, as well as from the natural lacquer film. These are attributed to the terminal groups of the synthesized lacquer film. In addition, alkenylphenois. aikyiphenols, alkenes and alkanes were detected by pyrolysis at 500°C after pyioiysis at 400°C. as well as in the natural lacquer film. Some alkenes and alkanes have longer carbon chains than the side chains of synthesized urushiol. The alkenylphenois and aikyiphenols are the pyrolysis products of the nucleus-side chain C-O coupling synthesized urushiol polymers, and the alkenes and alkanes, whose carbon chains are longer than the side chains of synthesized urushiol, are the pyrolysis products of autoxidative side chain-side chain C-C coupling synthesized urushiol polymer. Based on these results, it was found that the synthesized lacquer films are terminated with the monoenyl and saturated urushiol. and the polymerization of synthesized urushiol proceeds through the laccase-catalyzed nucleus-side chain C-O coupling and the autoxidative side chain-side chain C-C coupling like the natural lacquer film. Since the structure and polymerization mechanisms of the synthesized lacquer films are very similar to those of the natural lacquer film, these lacquer films must be tough and brilliant enough to be used as preservative surface coating materials like the natural lacquer film.