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Urushi lacquer

Urushiol yu- rii-she- 61, ii-, - ol [ISV, fr. Japanese urushi lacquer -f ISV -ol] (1908) n. A mixture of pyrocatechol derivatives with saturated or unsaturated side chains of 15 or 17 carbon atoms that is an oily toxic irritant principle present in poison ivy and some related plants (genus Rhus) and in oriental lacquers derived from such plants. Langenheim JH (2003) Plant resins chemistry, evolution ecology and ethnobotany. Timber Press, Portland, OR Paint pigment, drying oils, polymers, resins, naval stores, cellulosics esters, and ink vehicles, vol 3. American Society for Testing and Material, Conshohocken, PA, 2001. [Pg.1031]

The first paper mill was buUt by Eiichi Shibusawa in Tokyo in 1872. Some tons of natural rubber were imported from India and the USA in 1880-1890 and, concurrently, a rubber manufacturing company was buUt (1886). Celluloid products were first imported from Germany in 1877, and their domestic production started around 1890. The most interesting example is the Japanese urushi lacquer made from the poison oak tree. Because of its bright and clear color, the lacquer has been widely used from commodity to art works in Japan. In 1883, Hrkorokuro Yoshida published a research article on the urushi lacquer, describing an enzyme (later named laccase) that initiated the polycondensation of urushiol [5]. After 1903, scientific study on the urushi lacquer was continued by RUcou Majima [6]. [Pg.147]

The urushi lacquer has been used for more than 5000 years in China " and it is known as a highly durable material. Polymerization of urushiol, the major component of the lacquer, involves laccase-catalyzed dimerization and aerobic oxidative polymerization, " and the drying process takes a very long time. Several studies on shortening of this time have been carried out UV curing " " and hybridizing with other reactive polymers or monomers. " " Cardanol has a similar structure to urushiol, and the enzymatic oxidative polymerization of cardanol were reported by three research groups. " The development of the polymerization process leads to artificial urushi . [Pg.50]

For the preparation of lacquer ware, the oriental lacquer is usually applied on cedar wood, particularly from the Japanese cedar tree because it is the most warp resistant wood. One coat or two coats of primer, unprocessed urushi sap is applied followed by subsequent very thin layers (from twenty to forty layers) of processed "raw urushi" lacquer, one layer at the time every one or two days per application and curing. High relative humidity at the time of application and during curing is very critical it must be in the range from 65 to about 80%. ... [Pg.425]

Urushi, a natural lacquer, has been used on the ISFET surface [89] to make, amongst other devices, a chloride sensor. The natural lacquer has a long curing time (10 days) but this can be shortened to 2-3 days with the use of formaldehyde as a crosslinking agent [90] and has been successfully used in the production of a nitrate sensor. [Pg.111]

Sodium ion-selective field-effect transistors (Na+ ISFETs) were prepared by using three different types of polymeric matrix materials, such as polyvinyl chloride, bio-compatible polymer (polyurethane) and Urushi (natural oriental lacquer). Their electrochemical characteristics were discussed in connection with their characteristics of polymeric matrix membranes. [Pg.250]

Raw lacquer is called urushi. For our knowledge of the composition of urushi and the complex hardening process of the thin film layers, we now rely primarily on the recent work of Kumanotani and his coworkers (1-7). The sap of the Japanese lacquer tree is a latex containing 20-25% water, 65-70% urushic acid (urushiol), approximately 10% gummy sub-... [Pg.396]

Urushi, although it forms a thin film in an oxidation process, is unique in that it hardens in the presence of a high relative humidity. Hardening is actually accelerated with an increase in the amount of moisture present. Lacquer will not harden perfectly at normal room temperature and humidity conditions a good film is only possible in a damp enclosure between 20 and 28 °C. [Pg.397]

Many grades of urushi are used, depending on the different applications or decorative effects desired. (A detailed description of materials and methods may be found in Reference 8.) The sap, after removal of some water and careful filtration and cleaning, is most often coated onto a prepared core. This core is usually made of wood, but examples of leather, basketry, cloth, paper, metal, pottery, shell, horn, and fish skin may be found. Normally, many lacquer layers are built up on the core, with polishing occurring after each layer has hardened. [Pg.397]

Over the past hundred years numerous experimental methods have been used for the study of urushi and the finished lacquer ware. The first recorded reports on chemical experiments are those of Ishimatsu (14), Yoshida (13) and Korschelt and Yoshida (15). Miyama gave the name urushiol to urushic acid (16), and he and Majima and coworkers (17-26) further explored the composition of urushi. Work by Sunthanker, Dawson, and Symmes (27,28) helped to determine that it contained three substituted catechol derivatives containing various diflFerent side chains. The previously mentioned reports by Kumanotani and coworkers (1-7) have allowed us to understand more of the details of the raw urushi, the complex mechanism of film hardening, and some properties of the hardened layers. [Pg.398]

Urushi-ye (Japanese) n. A print for which lacquer is used to intensify the color. The term is generally employed to describe only the early hand-colored prints in which lacquers, colors, and metallic rust were applied to the printed black outline. Gair A (1996) Artist s manual. Chronicle Books LLC, San Francisco. Mayer R, Sheehan S (1991) Artist s handbook of materials and techniques. Viking Adult, New York. [Pg.1031]

Cardanol is a main component of thermally treated cashew nut shell liquid (CNSL), and is a phenolic compound with a long unsaturated hydrocarbon chain substituted in the meta position (Figure 2.17a). Urushiol, which is obtained from lacquer tree, poison ivy, poison oak, and poison sumac (Toxicodendron), and used for a raw material of a lacquer (urushi) in East Asia, is also a phenolic compound of catechol with a long unsaturated or saturated hydrocarbon chain (Figure 2.17b). Cardanol-based polymers have been reported very often, while there are a few research reports on urushiol-based polymers. Research on polymers synthesized from cardanol or CNSL are reviewed elsewhere.In the late 1980s, cardanol or CNSL-based polymers began to be reported as novel phenol-formaldehyde type resins and novel epoxy resins.Thereafter, Pillai and his co-workers have vigorously studied synthesis of various type of cardanol-based polymers polymers obtained... [Pg.49]

Concurrently, the Egyptians, Japanese, and Chinese were beginning to develop lacquers (Stillman, I960). Some time before 200 b.c., the Chinese used the exudation (sap) from the conifer Rhus vemicifera (which became known as the sumac or varnish tree) as a coating. This plant has also been called the urushi tree. The tree belongs to the same family as the poison ivy plant, and like it, all parts of the tree are toxic— tree, sap, and latex. Those who tap the tree must wear gloves and protective clothing. The active irritant is urushiol, a catechol derivative. [Pg.17]

The oriental lacquer is prepared from the sap of the varnish tree" Rhus verni-ciflua, which is an emulsion of an aqueous phase and an organic phase called urushi-ol. The urushi fraction consists of a mixture of catechol derivatives substituted in 3-po-sition with aliphatic C- 5 or C- 7 side chains. About 60% of these side chains are trie-nes. The structure of the trienes is similar to that in linseed or tung oil and is essential for the effectiveness of the oxidative curing of oriental lacquer. We have utilized new techniques and used combinations of modern techniques to analyze the urushiol mixtures and to characterize and identify each individual compound. We have also developed ultraviolet stabilizers for oriental lacquer, stabilizers that could be incorporated into the polymerizing mixture during the curing process to result in ultraviolet stabilized oriental lacquer. [Pg.423]

The difference between the oriental lacquer trees of the Rhus variety and the rubber tree is that the rubber trees have polyisoprene as the desirable ingredient while the urushi components are mixtures of substituted catechol derivatives. [Pg.424]

The sap of the Japanese, lacquer tree consists of a water/ oil emulsion, the "oily" or urushi-ol fraction (about 65%) and an aqueous fraction (35%) which contains water-soluble plant gums and polysaccharides as well as small amounts of enzymes. Urushi-... [Pg.424]

The number of layers depends on the intended quality of the final product, each layer is cured and sanded to guarantee the smoothness of the layers. Specially prepared urushi samples are used for the preparation of high quality Japanese lacquer ware. [Pg.425]

We have investigated [3-7] several samples of the urushi fraction of Japanese lacquer, obtained from the Urushi Co., Ltd., Kyoto, Japan by a combination of a.) capillary gas chromatography, b.) supercritical fluid chromatography, c.) high resolution NMR spectroscopy and d.) two techniques of mass spectrometry. The composition of the urushi fraction of these samples was found to consist of most of the components that have been identified by earlier analyses of urushi samples [8]. [Pg.425]

A most careful study was now carried out by NMR spectroscopy, not only by regular Ih 500 MHz and 13C but also by 1H COSY NMR spectroscopy [4,5). Individual compounds were isolated by preparative HPLC of the mixture in urushiol, particularly of kuro-urushi and all the isomers, including the cis-trans isomers were identified and characterized [Figure 4] [5). Particular care was taken to identify the water addition product [M]K" =371 daltons. It was found that water had indeed been added to the triene to form a C10 hydroxylated diene [Formula] [5]. This water addition is catalyzed by some additives such as ferric chloride which are used in the sugurome process to optimize the lacquer properties. The details of the process is a closely guarded secret and is slightly different from manufacturer to manufacturer. [Pg.427]

We have made it our objective to develop UV stabilizers that could be added to urushi and "cocured" to obtain a photo-stabilized oriental lacquer. We have synthesized several 2(2-hydroxyphenyl)2H-benzotriazole UV stabilizers, stearic, oleic, linoleic and linolenic acid esters of 2[2-hydroxy-3-tert-butyl-5(3 -hydroxypropyl)-phenyl]2H-benzotriazole [Equation] [7]. The compounds, pale yellow oils were characterized by their UV and K IDS mass spectra [Figure 6] [7]. All four compounds showed nearly identical UV spectra with two maxima at 305 and 340 nm. Those UV stabilizers have aliphatic side chains that are by six carbon atoms longer than the carbon side chains of the catechol derivatives of the urushi components. The unsaturated esters, especially the linolenic ester could readily be incorporated into urushiol or drying oil compositions and the unsaturated esters can be "co-cured" into UV stabilized oriental lacquer films. They could also be added to linseed oil and cured into films of drying oils. [Pg.429]

These types of boxes are well known for their thick layers of lacquers which are then carved. Two types of colors have been used to pigment oriental lacquer boxes even in early periods. One Is the vermilion color caused by an iron oxide pigment and the black color which Is caused by either magnetite, elemental iron or carbon black. Heavy pigmentation is needed because processed raw urushi used for painting has a deep bluelsh/black to black color. [Pg.430]


See other pages where Urushi lacquer is mentioned: [Pg.195]    [Pg.429]    [Pg.195]    [Pg.429]    [Pg.238]    [Pg.396]    [Pg.398]    [Pg.518]    [Pg.375]    [Pg.348]    [Pg.1031]    [Pg.785]    [Pg.141]   
See also in sourсe #XX -- [ Pg.147 ]

See also in sourсe #XX -- [ Pg.50 ]




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