Description

MANUFACTURING METHOD OF PURIFIED URUSHIOL AND PURIFIED URUSHIOL MANUFACTURED BY THE SAME

Technical Field

[1] The present invention relates to a method of manufacturing purified urushiol and purified urushiol manufactured thereby, and more particularly, to a method of manufacturing purified urushiol, including mixing crude lacquer with xylene, centrifuging the mixture, adding ammonia water and formalin, and conducting condensation and then purification at high temperatures, and to purified urushiol manufactured using the same. Background Art

[2] The lacquer tree (Rhus verniciflua or Rhus vernicifera) is a deciduous tree classified as Anacardiaceae, the original habitat of which is the Middle Asia highlands and Himalayan regions. The lacquer tree is presently widely distributed in many regions around the world, including tropical, subtropical, and temperate regions, and is mainly cultivated to obtain oriental lacquer in Southeast Asian regions including Korea, Japan and China.

[3] The lacquer tree, from which crude lacquer or lacquer sap is collected, has been known since ancient times to be effective in eliminating blood aggregation, in promoting blood circulation, in exterminating insects, and in treating stomachaches, gastric hyperacidity, cough, phthisis, menstrual cramps, constipation, glycosuria, and malaria, in the oriental medicine field. In recent years, anticancer effects have been reported. Furthermore, in Korea, the lacquer tree has been applied to chickens or ducks to improve people'health or for medicinal uses. In addition, the lacquer sap is durable and thus has been used as natural paint in large amounts, mainly by being applied on wood to produce articles for living, including wardrobes, vessels, spoons, chopsticks, and tables. It is also known that the lacquer sap has advantages such as high flame resistance, heat resistance, rot resistance, insect resistance, and electrical insulation properties, and furthermore, that the preservative quality thereof is good.

[4] However, since the uncured urushi lacquer coating causes an allergic reaction in the human body, general users are reluctant to employ such lacquer. For these reasons, urushi lacquer has numerous difficulties in use. In addition, the urushi lacquer coating begins to cure from the time that its surface comes into contact with moisture and oxygen, and has very low oxygen permeability and moisture permeanbility. Thus, in order to cure the inner portion of the coating, there is the need for a UV drying process or a process of repeatedly conducting application and curing of urushi lacquer through

a manual process, which is complicated. Thereby, the production cost increases, and economic benefits are negated, and consequently, it is difficult to realize industrial production of urushi lacquer products.

[5] The lacquer sap is composed of urushiol, water, rubber, laccase, and nitrogen- containing substances. Among these, urushiol plays a role as a main component, constituting about 70% of the lacquer sap and consists of 3-substituted catechol complex having C -alkyl or alkenyl groups, and the main ingredient thereof is 3-(8'Z, 11 'Z, lS'Z-pentadecatrieny^catechol, having three double bonds. 13 components of 3-substituted alkyl catechol, in which the number of double bonds in the C side chain is 0, 1, 2, or 3, have been established (Yumin Du and Ryuichi Oshima, J. of Chromatography, 284, 463-473 (1984)). Urushiol includes polymers resulting from natural polymerization of these monomers with laccase (Yamauchi, Y., T. Murakami and J. Kumanotani, J. of Chromatography, 214, 343-348 (1981); Yamauchi, Y., R. Oshima and J. Kumanotani, J. of Chromatography, 243, 71-84 (1982); and Y. Du, R. Oshima and H, Iwatsuki, J. of Chromatography, 295, 179-186 (1984)). Generally, in the case where the lacquer is used as paint, the higher the urushiol content contained in natural lacquer, the greater the quality and quantity.

[6] However, with regard to a method of manufacturing a urushiol fraction (Korean

Patent Application No. 10-1997-0013163) and to urushiol-ethanol nanoparticles having excellent anticancer effects, a manufacturing method thereof, and an anticancer composition containing the same (Korean Patent Application No. 10-1999-0016473), various attempts to purify urushiol have been made. However, there is still insufficient research on the purification of urushiol to make it suitable for mixing with synthetic resin and then injection-molding and also for facilitating printing or spray printing on aluminum, wood, PET films, paper, leather, various plastics, fabrics, and ironware. Disclosure of Invention Technical Problem

[7] Accordingly, an object of the present invention is to provide a method of manufacturing purified urushiol, which may be easily mixed with synthetic resin, including PA (polyamide), PC (polycarbonate), PE (polyethylene), ABS, PP (polypropylene), and PS (polystyrene), and which also functions to increase gloss and transparency and rapidly cures when printed or spray painted, to thus make it suitable for industrial uses, including interior and exterior construction materials.

[8] Another object of the present invention is to provide purified urushiol, which may be applied to printing or spray painting of environmentally friendly products exhibiting excellent far infrared emissivity, electromagnetic wave-blocking effects, and antibacterial activity.

Technical Solution

[9] In order to achieve the above abjects, the present invention provides a method of manufacturing purified urushiol, comprising mixing crude lacquer with xylene, and then centrifuging the mixture, thus separating an urushiol layer dissolved in xylene, and subjecting the urushiol, dissolved in xylene, to mixing with ammonia water and formalin, to condensation, and then to heating to remove xylene and water.

[10] The present invention provides separating the urushiol layer, comprising of conducting by mixing crude lacquer and xylene at a ratio of 1:1-1.5 and subjecting the mixture to centrifugation at 4,000-6,000 rpm for 10-20 min. And the present invention provides the manufacturing purified urushiol, comprising the purified urushiol is prepared by subjecting the urushiol layer, separated through centrifugation, to addition with 8-14 wt% of ammonia water and 4-14 wt% of formalin based on weight of the urushiol and xylene contained therein, to condensation at 30-80 rpm for 2-4 hours, and then to heating to 80~100°C to remove xylene and water.

[11] In addition, the present invention further comprises to add epoxy resin and n- butanol and then conducting heating and dissolution, after the heating, at this time the adding the epoxy resin and the n-butanol is conducted by mixing the purified urushiol and epoxy resin at a ratio of 1:0.8-1.2, adding 4-6 wt% of n-butanol, based on weight of the purified urushiol, and then dissolving the mixture through heating to 120~160°C for 30-90 min.

[12] The present invention comprises to add xylene and phosphoric acid, after the dissolving. At this time, the adding the xylene and the phosphoric acid is conducted by mixing the dissolved solution with 90-120 wt% of xylene and 0.5-5 wt% of phosphoric acid based on weight of the purified urushiol.

[13] The present invention provides the purified urushiol manufactured using the above method.

[14]

[15] Hereinafter, a detailed description will be given of the present invention.

[16] In the present invention, lacquer sap, which is native to Korea, China or Japan, may be used without limitation. Crude lacquer is filtered using filter paper to remove impurities therefrom, mixed with ethanol, and then centrifuged. Mixing with xylene is conducted to separate urushiol from the lacquer sap through centrifugation. Here, in place of xylene, any organic solvent, including benzene, toluene, and ethanol, may be used. However, to remove the solvent through evaporation and to reuse the solvent in a subsequent process, xylene is particularly useful.

[17] With the aim of sufficiently dissolving crude lacquer in xylene for easy centri fugation, it is preferred that crude lacquer and xylene be mixed at a ratio of 1:1-1.5. In

the case where the mixing ratio of xylene is less than 1, the viscosity of the solution is low, and thus the rubber or nitrogen compound is not sufficiently separated upon cen- trifugation. On the other hand, if the mixing ratio exceeds 1.5, the solvent is used in an unnecessarily high amount, undesirably increasing expenses through increased evaporation. When centrifugation is conducted at 4,000-6,000 rpm for 10-20 min, a solid precipitate, including a rubber or nitrogen compound, settles as a lower layer, and thus it is possible to separate an urushiol layer, dissolved in ethanol, as an upper layer, from the lower layer.

[18] Urushiol dissolved in xylene is mixed with ammonia water and formalin, and is then subjected to condensation at high temperatures. In this case, ammonia water, which is an aqueous alkali solution, functions to adjust the pH of urushiol, dissolved in xylene, to 8, and thus it is used as a catalyst for the condensation of formalin and urushiol. Formalin functions to cause condensation with urushiol to thus form an oligomer so as to realize high-temperature curing without the action of an enzyme.

[19] The urushiol layer, separated through centrifugation, is mixed with 8-14 wt% of ammonia water and 4-14 wt% of formalin, based on the weight of urushiol and xylene contained therein, subjected to condensation at 30-80 rpm for 2-4 hours, and then heated to 80~100°C to thus remove xylene and water, thereby preparing purified urushiol.

[20] The present inventors added ammonia water thereto in an amount calculated according to Equation 1 below, and added formalin in an amount calculated according to Equation 2 below:

[21] Equation 1

[22] (Urushiol+Xylene) Weight x

3 - 5 wt%

0.37

[23] Equation 2

[24] (Urushiol+Xylene) Weight urusϊtiol wt % 30 ,. _λ x x x 0 9

314 0.28

[25] The purified urushiol, manufactured according to the present invention, is easily mixed with various types of ink or pigment and synthetic resin, and thus may be printed or spray painted on aluminum, wood, PET films, paper, leather, various plastics, fabrics, and ironware. Further, the main component of the lacquer sap functions to exhibit excellent far infrared emissivity, electromagnetic wave-blocking effects, and antibacterial activity, thus making it possible to produce environmentally friendly products.

[26] To increase printing quality, gloss, and transparency in the printing process, the purified urushiol is added with epoxy resin and n-butanol. The epoxy resin is a flexible material for increasing gloss and enabling efficient printing. The purified urushiol and the epoxy resin are mixed at a ratio of 1:0.8-1.2. The n-butanol, which functions to dissolve the resin, is used in an amount of 4-6 wt% based on the weight of purified urushiol, and is preferably dissolved through heating at 120~160°C for 30-90 min.

[27] Further, xylene for adjusting the viscosity and phosphoric acid for facilitating the curing of epoxy resin are preferably added. To the solution of epoxy resin and n- butanol, xylene is added in an amount of 90-120 wt% and phosphoric acid is added in an amount of 0.5-5 wt%, based on the weight of the purified urushiol. When xylene and phosphoric acid are added too rapidly, the chemical reaction is remarkably decreased. Hence, these components are preferably slowly added and then heated to 120~160°C for 60-90 min.

Advantageous Effects

[28] According to the present invention, the method of manufacturing purified urushiol enables the manufacture of purified urushiol, which may be easily mixed with various types of ink or pigment and synthetic resin to thus make it suitable for printing or spray painting on aluminum, wood, PET films, paper, leather, various plastics, fabrics, and ironware. Further, the main component of the lacquer sap functions to exhibit far infrared emissivity, electromagnetic wave-blocking effects, and antibacterial activity, therefore making it possible to produce environmentally friendly products. Best Mode for Carrying Out the Invention

[29] A better understanding of the present invention may be obtained through the follow examples, test examples and tables, which are set forth to illustrate, but are not to be construed as the limit of the present invention.

[30]

[31] Example 1. Manufacture of Purified Urushiol 1

[32] 1 kg of crude lacquer, native to China, was mixed with 1.2 kg of xylene and then centrifuged at 5,000 rpm for 15 min, thus separating 2 kg of an urushiol layer, dissolved in xylene, from a pellet precipitate including a rubber and nitrogen compound. The separated urushiol layer was added with 200 g of ammonia water to thus adjust the pH thereof to 8, mixed with 150 g of formalin, subjected to condensation at 8O ⁰ C and 60 rpm for 3 hours, and then heated to 9O ⁰ C using a high- temperature purifier (available from Korea National) to thus remove xylene and water, thereby obtaining 400 g of purified urushiol.

[33] The ammonia water was added in an amount calculated according to Equation 1, and formalin was added in an amount calculated according to Equation 2.

[34]

[35] Example 2. Manufacture of Purified Urushiol 2

[36] To increase printing quality, gloss, and transparency upon printing, the purified urushiol of Example 1 was mixed with epoxy resin at a ratio of 1 : 1 , added with 20 g of n-butanol, mixed, and then dissolved at 14O ⁰ C for 2 hours. Subsequently, the mixed solution was cooled to 100 C or lower, slowly added with 400 g of xylene and 4 g of phosphoric acid based on the weight of purified urushiol, mixed, and then heated to 120~160°C for 60-90 min, thus preparing 982 g of purified urushiol.

[37]

[38] Preparative Example 1. Coating of Aluminum Sheet using Purified Urushiol

[39] An aluminum sheet (H-26, available from Alcoa), having a thickness of 0.5 mm and a weight of 0.25-0.30 kg, was surface polished and washed with water. Then, to form an oxide film 1.5-2.5 mm thick on the aluminum sheet, the aluminum sheet was subjected to surface cleaning using a degreasing agent and then to pretreatment using 2 kg of an acidic chromate solution diluted with water. Thereafter, the aluminum sheet was printed with a pattern designed through offset V printing and then dried in a box oven (available from Taeyang Electronic Company) at 18O ⁰ C for 1 hour.

[40] The purified urushiol of Example 2 was applied to a thickness of 1.5-2.5 mm on the aluminum sheet, printed through silk printing, and then dried in a box oven at 16O ⁰ C for 1 hour, thus preparing an aluminum sheet coated with purified urushiol.

[41]

[42] Preparative Example 2: Manufacture of MDF Panel using Purified Urushiol

[43] 10 wt% of the purified urushiol obtained using the method of Example 2 was mixed with 90 wt% of a melamine resin solution (available from Korea Gravure), thus preparing 1 kg of a mixture solution.

[44] Gravure printing paper, which is paper weighing 80 g/m and printed with a woodgrain pattern through gravure printing, was immersed in the above mixture solution to thus coat both surfaces of the printing paper, and then dried at 12O ⁰ C for 90 sec. The dried printing paper was thermocompressed on an MDF panel at 18O ⁰ C for 45 sec at 25 kg/cm to thus adhere it to the panel, thereby manufacturing an MDF (Medium Density Fiberboard) panel.

[45]

[46] Test Example 1. Measurement of Thickness and Gloss of Coating Film

[47] The thickness and gloss of the coating film of the aluminum sheet coated with the purified urushiol, obtained in Preparative Example 1, were measured. The gloss was evaluated at an incident angle of 60 using a glossmeter, available from BYK. The results are shown in Table 1 below.

[48]

[49] Table 1

[50] [51] As is apparent from Table 1, an aluminum sheet having superior gloss could be produced even though the coating film thereof had the above thickness.

[52] [53] Test Example 2. Test of Far Infrared Emissivity [54] The emissivity of far infrared rays from the MDF panel manufactured in Preparative Example 2 was measured by the Korea Institute of Far Infrared Applied Estimation at the present inventor's request.

[55] Specifically, the emissivity of the above panel was measured at 37 ⁰ C using an FT- IR spectrometer, and was compared to that of a black body. The results are shown in Table 1 below. From this, the far infrared emissivity was seen to be superior.

[56] [57] Table 2

[58] [59] Test Example 3. Test of Antibacterial Activity [60] The test for antibacterial activity of the MDF panel manufactured in Preparative Example 2 was performed by the Korea Testing and Research Institute for Chemical Industry at the present inventors request. In this case, the test strains were Escherichia CoIi (ATCC 8739) and Staphylococcus aureus (ATCC 6538). As a coating film and control sample, a sterile polybag for a Stomacher 400 was used.

[61] [62] Table 3

[63] [64] Here, A is the initial bacterial cell number (average) of the control sample, B is the bacterial cell number (average) of the control sample after 24 hours of incubation, and C is the bacterial cell number (average) of the test sample of the present invention after 24 hours of incubation. In addition, an antibacterial value (log(B/C)) is obtained by subtracting log(C/A) from log(B/A).

[65] As is apparent from Table 3, the panel manufactured using the purified urushiol of the present invention could be seen to exhibit superior antibacterial activity.

[66] [67] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. Industrial Applicability

[68] According to the present invention, the method of manufacturing purified urushiol enables the manufacture of purified urushiol, which may be easily mixed with various types of ink or pigment and synthetic resin to thus make it suitable for printing or spray painting on aluminum, wood, PET films, paper, leather, various plastics, fabrics, and ironware. Further, the main component of the lacquer sap functions to exhibit far infrared emissivity, electromagnetic wave -blocking effects, and antibacterial activity, therefore making it possible to produce environmentally friendly products.