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Title:
INORGANIC PAINT COMPOSITION COMPRISING URUSHIOL AND PREPARATION METHOD THEREOF
Document Type and Number:
WIPO Patent Application WO/2009/057935
Kind Code:
A1
Abstract:
Provided is an inorganic paint composition comprising urashiol. It comprises urushiol in an amount of from 0.1 to 100 parts by weight based on 100 parts by weight of a solid content of a base resin comprising (a) a colloidal dispersion selected from a group consisting of colloidal silica, colloidal zirconia, colloidal alumina and combinations thereof, (b) a compound selected from a group consisting of alkoxy silane, a silane coupling agent, hydrolysates thereof, and partial condensates thereof, (c) a compound selected from a group consisting of zirconium alkoxide, hydrolysates thereof, partial condensates thereof, and (d) an organic solvent.

Inventors:
KOH, Se Jong (607-302, Mokryeon Doosan Apt.Beomgye-dong, Dongan-g, Anyang-si Gyeonggi-do 431-722, KR)
KWON, Seung Hyeop (B-807, Halla Gungjeon Apt.110, Taehwa-dong, Jung-gu, Ulsan 681-320, KR)
Application Number:
KR2008/006366
Publication Date:
May 07, 2009
Filing Date:
October 29, 2008
Export Citation:
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Assignee:
NURIDLE CO., LTD. (1102, Gyeonggi Knowledge Asset Anyang Center1591-9, Gwanyang-dong, Dongan-g, Anyang-si Gyeonggi-do 431-060, KR)
KOH, Se Jong (607-302, Mokryeon Doosan Apt.Beomgye-dong, Dongan-g, Anyang-si Gyeonggi-do 431-722, KR)
KWON, Seung Hyeop (B-807, Halla Gungjeon Apt.110, Taehwa-dong, Jung-gu, Ulsan 681-320, KR)
International Classes:
C09D1/02
Attorney, Agent or Firm:
CHANG & HAN PATENT & LAW FIRM (1007, 10Fl. Woolim e-Biz Center 2184-1, Guro-dong, Guro-gu, Seoul 152-848, KR)
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Claims:

Claims

[1] An inorganic paint composition, comprising urushiol in an amount of from 0.1 to

100 parts by weight based on 100 parts by weight of a solid content of a base resin comprising (a) a colloidal dispersion selected from a group consisting of colloidal silica, colloidal zirconia, colloidal alumina and combinations thereof, (b) a compound selected from a group consisting of alkoxy silane, a silane coupling agent, hydrolysates thereof, and partial condensates thereof, (c) a compound selected from a group consisting of zirconium alkoxide, hydrolysates thereof, partial condensates thereof, and (d) an organic solvent.

[2] The inorganic paint composition according to claim 1, wherein the urushiol is extracted by sufficiently stirring natural raw lacquer resin from a lacquer tree with an organic solvent and then in combination with water, leaving the resulting mixture for a time to form two separate layers, freezing the aqueous layer, and recovering the organic layer.

[3] The inorganic paint composition according to 1, wherein the alkoxy silane is selected from a group consisting of tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltri- ethoxysilane, diphenyldiethoxysilane, isobutyltrimethoxysilane, methyltriiso- propoxysilane, tetrapropoxysilane, and combinations thereof.

[4] The inorganic paint composition according to claim 1, wherein the silane coupling agent is selected from a group consisting of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, vinyltri(β-methoxyethoxy)silane, β- (3 ,4-epoxycyclohexyl)ethyltrimethoxysilane, γ- glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ- glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ- methacryloxypropylmethyldimethoxysilane, γ- methacryloxypropyltrimethoxysilane, γ- methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N- β- (aminoethyl) -γ- aminopropyltrimethoxy silane , N- β-(aminoethyl)-γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, and combinations thereof.

[5] The inorganic paint composition according to claim 1, wherein the zirconium alkoxide is selected from a group consisting of zirconium(IV) tert-butoxide, zirconium(IV) butoxide, zirconium(IV) ethoxide, sirconium(IV) propoxide,

zirconium(IV) isopropoxide, and combinations thereof.

[6] The inorganic pain composition according to claim 1, wherein the organic solvent is selected from a group consisting of alcohols including methanol, ethanol, isopropanol and butanol, ketones including acetone, diacetone alcohol, acetylacetone and methylethylketone; cellosolves including methylcellosolve, ethylcellosolve, butylcellosolve and cellosolveacete, and combinations thereof.

[7] The inorganic paint composition according to claim 1, wherein the base resin further comprises a hydrolysis catalyst or an additive.

[8] A method for preparing an inorganic paint composition, comprising: stirring natural raw lacquer resin in an organic solvent and then in combination with water; separating an organic layer containing urushiol from an aqueous layer; preparing a base resin comprising (a) a colloidal dispersion selected from a group consisting of colloidal silica, colloidal zirconia, colloidal alumina and combinations thereof, (b) a compound selected from a group consisting of alkoxy silane, a silane coupling agent, hydrolysates thereof, and partial condensates thereof, (c) a compound selected from a group consisting of zirconium alkoxide, hydrolysates thereof, partial condensates thereof, and (d) an organic solvent; and mixing the base resin with the separated urushiol.

Description:

Description

INORGANIC PAINT COMPOSITION COMPRISING URUSHIOL AND PREPARATION METHOD THEREOF

Technical Field

[1] The present invention relates to an inorganic paint composition which comprises inorganic paint in combination with urushiol extracted from natural raw lacquer resin and which is thus environmentally friendly, exhibits excellent adhesiveness to materials, weather resistance, thermal resistance, wear resistance, antifouling property, water proofing, chemical resistance, antibacterial activity, electromagnetic wave shielding property, and electrical insulation in addition to the characteristic elegant color. Also, the present invention is concerned with a method of preparing the composition, takes a short time for the preparation thereof, and can be easily coated. Background Art

[2] Most artificial chemical products contain materials harmful to the environment and the body, thus inducing various diseases and allergic reactions. In addition, they are not readily decomposed in the ecosystem, thereby producing environmental pollution. For these reasons, there is an increase in demand for environmentally friendly products. To meet this demand, lacquer resins from lacquer trees are applied for the production of a variety of environmentally friendly products.

[3] Exhibiting safety, salinity tolerance, thermal resistance, waterproofing, antisepsis, insect repellency, electrical insulation, and antibacterial properties, lacquer resin has long been applied to various goods such as tableware, furniture, etc. In fact, many of the relics which have been excavated as being intact were found to be japanned. In consideration of such findings, the lacquer resin from lacquer trees can find a broad range of applications thanks to the excellent properties thereof.

[4] In the natural lacquer resin, urushiol, water, monosaccharides, polysaccharides, and a small amount of enzymes are found. Of them, urushiol with a phenol group is known as a main component of the film. A relative humidity of 80% and a temperature of approximately 3O 0 C are required for curing urushiol.

[5] The curing is accomplished by the oxidation of urushiol in contact with moisture and oxygen. Thus, a thick film is not obtained by one stroke with a brush, but can be formed by repeatedly brushing and curing in an alternating manner. During these alternating processes, the film thus formed may be apt to be contaminated with impurities such as dust in air. For this reason, the work place must be cleaned.

[6] Further, the curing of the lacquer resin only with moisture and oxygen involves problems in terms of storage. In spite of such various problems, however, the natural

lacquer resin has great advantages over artificial paints in terms of elegant appearance, natural color, solvent resistance, thermal resistance, fire resistance, antibacterial activity, chemical resistance and durability, and extensive research into the natural lacquer resin has been conducted, resulting in many patents and products.

[7] Korean Patent No. 0631489, entitled "Production method of lacquer resin from lacquer extract from lacquer tree", discloses a method in which a lacquer extract is obtained from lacquer tree barks in a nitrogen atmosphere using an organic solvent, filtered and concentrated to separate urushiol, rubber matter, and glycoproteins, followed by vacuum concentration and recombination of the separated components.

[8] However, this method is complex and difficult to apply to mass production because it requires long periods of time for separation and concentration in a nitrogen atmosphere. In addition, the filtered and recombined lacquer resin is not different from raw lacquer resin, except that it is free of impurities.

[9] Korean Patent No. 0477932 (entitled "Recombined Natural Lacquer Resin and

Process for Preparing the Same") discloses that the natural lacquer resin is separated into its components which are then recombined and polymerized in the presence of enzymes, thus bringing about an improvement in quality consistency, workability and economy.

[10] However, this method requires the same curing conditions, including a relative humidity of 70% and a temperature of 2O 0 C or higher, as in conventional methods, and the procedure is complex due to the separation and polymerization processes. Further, this method is difficult for non-experienced persons to apply to mass production because the film varies in its gloss property depending on curing conditions, and is apt to wrinkle and to be contaminated with dust due to slow curing.

[11] Korean Patent No. 0596718 (entitled "Paint Composition Comprising Urushiol and

Manufacturing process thereof) discloses that a lacquer resin extract is separated into its components which are then polymerized to a high degree through enzyme polymerization and thermal polymerization, followed by the addition of a small amount of metal curing agent to rapidly cure the resin.

[12] This method suffers from the disadvantages of using a special device, such as a bubble column reactor, requiring a long period of time for separation and thermal polymerization, and of being difficult to control the thermal polymerization at high temperatures required.

[13] Korean Patent NO. 0332702 (entitled "New coating material based on urushiol and curing method") suggests modified urushiol. Urushiol extracted from raw lacquer resin is thermally cured to give urushiol oligomers with a molecular weight of 3,000-10,000 which are modified by epoxylation and then by treatment with a base, and the modified urushiol is used alone or in combination with a suitable diluent.

[14] This patent is disadvantageous in that the process is complex and time-consuming and is difficult to control in terms of oligermerization.

[15] Korean Patent No. 0434199 (entitled "Anti-corrosive epoxy coating composition containing lacquer") discloses an anti-corrosive epoxy coating composition comprising epoxy resin and an amine-based curing agent in combination with additives such as natural lacquer components and a drying agent.

[16] The addition of natural lacquer components to epoxy resin must be carefully controlled. Just before brushing, the curing agent must be added to the epoxy resin. In addition, a limitation is imparted to the use of the epoxy resin because it is resistant to alkali, but vulnerable to acid. Above all, the coating composition based on epoxy resin is not appreciably different from conventional chemical paint compositions.

[17] Korean Patent Nos. 0653277 (entitled "Coating method of metal sheet using Urushiol lacquer mixture), 0536953 (entitled "Coating method of metal sheet by japanning), 0653279 (entitled "Coating method of synthetic resin using urushiol lacquer mixture), and 0637723 (entitled "Coating method of metal sheet by silk screen-printing mixture of ink and urushiol lacquer", and Korean Patent Laid-Open Publication No. 2007-0006005 (entitled "Coating method of metal sheet by silk screen-printing mixture of ink and urushiol lacquer")introduce methods of coating various applications with natural urushiol lacquer mixtures.

[18] Nowhere is a description given of the preparation of filtered natural lacquer in these prior arts. Particularly, when used in mixture with chemical lacquer, the natural lacquer loses the environmentally friendly property thereof. Additionally, the prior disclosures are complex since several processes are required for improving the coating in adhesiveness and surface hardness.

[19] Consequently, the conventional techniques described above are complex, require highly moist conditions and a temperature of 3O 0 C or higher, and need many rounds of coating processes since a desirable coating thickness cannot be obtained by one round of brushing. Further, special attention must be paid so as not to prevent the natural lacquer from being in contact with moisture and oxygen during the storage thereof. Disclosure of Invention Technical Problem

[20] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a paint composition which can be prepared using a simple process, is friendly to the environment and shows storage stability and with which a good coating can be obtained by brushing once, thus applying to the mass production of japanned products. Technical Solution

[21] The above object can be accomplished by the provision of an inorganic paint composition comprising urashiol in an amount of from 0.1 to 100 parts by weight based on 100 parts by weight of a solid content of a base resin comprising (a) a colloidal dispersion selected from a group consisting of colloidal silica, colloidal zirconia, colloidal alumina and combinations thereof, (b) a compound selected from a group consisting of alkoxy silane, a silane coupling agent, hydrolysates thereof, and partial condensates thereof, (c) a compound selected from a group consisting of zirconium alkoxide, hydrolysates thereof, partial condensates thereof, and (d) an organic solvent.

[22] The colloidal dispersion useful in the present invention employs water or alcohol as a dispersant. Colloidal silica may be used as a colloidal dispersion. Suitable is amorphous silica sol or a stable dispersion with a diameter of from 5 to 100 nm, such as commercially available products, identified as Ludox from DuPont or Snowtex from Nissan Chemical, Japan.

[23] Colloidal zirconia or colloidal alumina with a particle size of from 5 to 100 nm may be also useful as a colloidal dispersion. These colloidal dispersions may be used alone or in combination depending on the adhesiveness and surface hardness of coating on the materials to be coated.

[24] In consideration of pH adjustment and storage stability of the reaction solution, the colloidal particles useful in the present invention preferably range in size from 10 to 50 nm, with a content of from 5 to 60 % by weight and preferably from 10 to 40 % by weight based on the total solid weight of the base resin.

[25] When used in an amount of less than 5 % by weight, the colloidal dispersion makes the coating poor in terms of hardness and thermal resistance. On the other hand, an amount greater than 60% by weight of the colloidal dispersion may cause a decrease in gloss and the generation of pinholes in the coating.

[26] The alkoxy silane useful in the composition may be selected from a group consisting of tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, tetraethoxysilane, methyltri- ethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltrimethoxysilane, methyltriisopropoxysilane, tetrapropoxysilane and a combination thereof.

[27] Examples of the silane coupling agent include a vinyl compound such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, and vinyltri(β-methoxyethoxy)silane, an epoxy compound such as β- (3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ- glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltriethoxysilane, andγ- glycidoxypropylmethyldimethoxysilane; a methacryloxy compound such as γ-

methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ- methacryloxypropylmethyldiethoxysilane, and γ-methacryloxypropyltriethoxysilane; an amino compound such as N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N- β-(aminoethyl)-γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and γ- aminopropyltriethoxysilane; and a mercapto compound such as γ- mercaptopropyltrimethoxysilane. These silane coupling agents may be used alone or in combination depending on the coating condition of the final composition.

[28] In the composition of the present invention, the compound selected from among alkoxy silane, a silane coupling agent, hydrolysates thereof and partial condensates th ereof is present in an amount of from 10 to 70 % by weight based on the weight of the total solid content of the base resin, and preferably in an amount of from 20 to 50 % by weight. When the content of the compound is less than 10 % by weight, deterioration occurs in the physical properties of the coating, such as adhesiveness and hardness. On the other hand, a content greater than 70 % by weight of the compound makes the coating apt to crack and peel off and makes it impossible to store the composition for a long term due to poor storage stability.

[29] Examples of the zirconium alkoxide useful in the composition of the present invention include zirconium(IV) tert-butoxide, zirconium(IV) butoxide), zirconium(IV) ethoxide, zirconium(IV) propoxide, and zirconium(IV) isopropoxide, which may be used alone or in combination.

[30] As for the compound selected from among zirconium alkoxide, hydrolysates thereof and partial condensates thereof, its content in the composition of the present invention ranges from 0.1 to 50 % by weight based on the weight of total solid content of the base resin and preferably from 1 to 20 % by weight. When the content is less than 0.1 % by weight, the curing properties are deteriorated to exert a negative effect on the physical properties of the coating. A content exceeding to 50 % by weight gives a light yellow color to the coating, thus decreasing the transparency of the coating.

[31] An alcohol, a ketone or a cellosolve may be used as an organic solvent in the present invention. Examples include methanol, ethanol, isopropanol, butanol, acetone, diacetone alcohol, acetylacetone, methylethylketone, methylcellosolve, ethyl- cellosolve, butylcellosolve, and cellosolveacetate. The organic solvent is used in such an amount as to reduce the total solid content of the inorganic paint composition comprising uroshiol to within the range of from 5 to 50 % by weight.

[32] In addition the above-mentioned ingredients, the base resin of the present invention may further comprise a hydrolysis catalyst and an additive.

[33] The hydrolysis catalyst may be an acid or base catalyst and functions to adjust pH values and reaction rates and to endow storage stability and dispersibility on the final

sol.

[34] Examples of the acid catalyst include acetic acid, phosphoric acid, sulfuric acid, hydrochloric acid, nitric acid, chlorosulfonic acid, para-toluenesulfonic acid, trichloroacetic acid, polyphosphoric acid, and iodic acid. For the base catalyst, sodium hydroxide, an aqueous ammonium solution, potassium hydroxide, normal butyl amine, imidazole, ammonium perchlorate, trimethyl amine, and triethyl amine may be exemplified.

[35] In consideration of various factors including the storage stability and pH of the dispersion, reaction rates depending on the ingredients used, adhesiveness to materials to be coated, etc, these acid or base catalysts may be used alone or in combination.

[36] Based 100 parts by weight of the total solid content of the base resin, the hydrolysis catalyst may be used in an amount of from 0.1 to 10 parts by weight. An amount less than 0.1 parts by weight requires a long period of time for hydrolysis and polycon- densation and causes he coating to be non-uniform. On the other hand, when the amount exceeds 10 parts by weight, the composition suffers from the disadvantage of becoming poor in storage stability and adhesiveness.

[37] With the aim of overcoming the problems occurring in physical properties of the coating or during the formation of the coating, the composition may further comprise various additives in such an amount as not to deteriorate the physical properties of the composition.

[38] Examples of the additives which may be used in the present invention include a leveling agent, a surface slipping agent, a wetting agent, a fluidity adjusting agent, and a metal additive, which may be used alone or in combination.

[39] The additives such as leveling agents, surface slipping agent, a wetting agent and a fluidity adjusting agent may be selected from the products commercially available from BYK-Chemie or Tego chemie service.

[40] For use as an antibacterial agent, the metal additive may be silver (Ag), platinum (Pt) or copper (Cu), which may be used alone or in combination.

[41] The amount of these additives falls within the range of from 0.01 to 5 parts by weight based on 100 parts by weight of total solid content of the base resin. When too much additives are used, the production cost increases and the metal is deposited, causing a problem in storage stability. On the other hand, when too small additives are used, desired antibacterial activity cannot be obtained.

[42] Urushiol, a main component of the paint composition according to the present invention, is separated from the raw lacquer resin taken from lacquer trees. In greater detail to a raw lacquer resin from lacquer trees is added an organic solvent which is then sufficiently stirred. Water is also added to the lacquer resin and stirred sufficiently. Thereafter, the resulting mixture is allowed to stand for a predetermined time

to induce layer separation. Freezing is followed by the separation of the layers from each other. The content of urushiol in the base resin is determined depending on the quality and state of materials to be coated, the color or properties of the coating formed, and coating methods.

[43] Based on 100 parts by weight of total solid content of the base resin, urushiol is used in an amount of from 0.1 to 100 parts by weight and preferably in an amount of from 1 to 60 parts by weight. When the amount is below 0.1 parts by weight, brushing must be conducted many times to express the characteristic color of the natural lacquer. On the other hand, when the amount is greater than 100 parts by weight, the coating is apt to swell during a curing process and thus is formed as having a non-uniform surface.

[44] The inorganic pain composition comprising urushiol in accordance with the present invention may be applied by various coating processes depending on the materials to be coated. For example, role coating, immersion coating, spray coating, flow coating, silk screen printing, or spin coating may be used. Curing conditions for the coating may vary depending on the components and formulation ratios of the composition and kinds of the material to be coated. Typically, the coating is cured at a temperature less than the softening point of the material, for example, 60 ~ 200 0 C, for about 10 min to hours.

[45] As long as it is coated with the composition of the present, any material can be used.

To almost all materials including metals, ceramics, plastics and woods, the composition of the present invention may applied. In addition, a good coating can be obtained by brushing once with the composition of the present invention.

[46] The coating formed of the inorganic paint composition comprising urushiol in accordance with the present invention exhibits excellent adhesiveness, weather resistance, thermal resistance, wear resistance, antifouling property, water proofing, chemical resistance, antibacterial activity, electromagnetic wave shielding property, and electrical insulation in addition to the characteristic elegant color.

[47] In accordance with another aspect thereof, the present invention pertains to a method for preparing an inorganic paint composition, comprising:

[48] stirring natural raw lacquer resin in an organic solvent and then in combination with water;

[49] separating an organic layer containing urushiol from an aqueous layer;

[50] preparing a base resin comprising (a) a colloidal dispersion selected from a group consisting of colloidal silica, colloidal zirconia, colloidal alumina and combinations thereof, (b) a compound selected from a group consisting of alkoxy silane, a silane coupling agent, hydrolysates thereof, and partial condensates thereof, (c) a compound selected from a group consisting of zirconium alkoxide, hydrolysates thereof, partial condensates thereof, and (d) an organic solvent; and

[51] mixing the base resin with the separated urushiol.

[52] Urushiol can be extracted by sufficiently stirring raw lacquer resin from a lacquer tree with an organic solvent and then in combination with water and leaving the resulting mixture for a time to form two separate layers. Urushiol is dissolved in the upper organic solvent while the other components are present in the aqueous layer.

[53] Storage in a freezing chamber causes the aqueous layer to be frozen while the organic layer remains unfrozen, so that the upper layer can be readily separated. Cen- trifugation after the mixing step allows quick layer separation.

[54] For the preparation of the inorganic base resin, first, 5 ~ 60 % by weight of a colloidal dispersion of colloidal particles in a dispersant selected from among water with pH 2 ~ 11 or an alcohol, the colloidal particles being selected from among colloidal silica, colloidal zirconia, colloidal alumina and combinations thereof; 10 - 70 % by weight of a compound selected from among alkoxy silane, a silane coupling agent, hydrolysates thereof and partial condensates thereof; 0.1 ~ 10 % by weight of a hydrolysis catalyst are mixed together and stirred at 50 ~ 8O 0 C for 3 - 12 hours.

[55] To the resulting mixture is added an organic solvent in such an amount as to adjust a total solid content to 5 - 50 % by weight, followed by adding the additives in an amount of 0.01 - 5 parts by weight based on 100 parts by weight of the solid content so as to control various properties including coatability, adhesiveness, curing properties, etc.

[56] In greater detail colloidal silica is subjected, together with alkoxy silane, to hydrolysis and condensation in the presence of a hydrolysis catalyst, followed by terminating the reaction with zirconium alkoxide to afford a base resin. The urushiol separated from natural raw lacquer resin is mixed with the base resin. At this time, the addition of an organic solvent and additives to the base resin provides desired physical properties for the inorganic paint composition in accordance with the present invention.

Advantageous Effects

[57] As described above, the inorganic paint composition comprising urushiol in accordance with the present invention is friendly to the environment, highly adhesive to any material to be coated, shows excellent properties including weather resistance, thermal resistance, wear resistance, antifouling property, water proofing, chemical resistance, antibacterial activity, electromagnetic wave shielding property, and electrical insulation in addition to characteristic elegant color, takes a short time for the preparation thereof, and can be easily coated.

[58] Also, after the composition is applied to a material, an urushiol coating can be readily obtained by simple thermal treatment at a suitable temperature. These simple coating

and thermal treatment processes give a new way to circumvent the problem of conventional techniques in mass production, and allows the composition to be applied to any material including metals, ceramics, plastics, woods, etc. Best Mode for Carrying out the Invention

[59] A better understanding of the present invention may be obtained through the following examples which are set forth to illustrate, but are not to be construed as limiting the present invention.

[60] EXAMPLE 1 : Separation of Urushiol

[61] In an Erlenmeyer flask, 300 g of n-hexane was added to 100 g of raw natural Chinese lacquer resin and vigorously stirred. Then, 100 g of distilled water was added to the lacquer and stirred, followed by leaving the mixture at room temperature for 30 min before storage in a freezing chamber.

[62] After two separate layers were formed, the lower layer was frozen. The upper layer was obtained and filtered.

[63] Distillation at 6O 0 C in a reactor afforded 150 g of urushiol from 300 g of the filtered solution.

[64] EXAMPLE 2: Preparation of Base Resin

[65] 80 g of a dispersion of colloidal silica (MA-ST, Nissan Chemical) in methanol 80g was placed in a reactor. 30 g of 0.5 wt% aqueous nitric acid solution was added to the reactor and stirred for 10 min. Then, 200 g of γ-glycidoxypropyltrimethoxysilane (A- 187, GE Toshiba Silicones) and 50 g of tetraethoxysilane (TEOS Pure, GE Toshiba Silicones) were added and stirred for 1 hour.

[66] 100 g of acetylacetone, 130g of methanol and 80 g of zirconium butoxide

(Tyzor-NBZ, DuPont) were added to the reactor which was then maintained at 6O 0 C for 3 hours under a reflux condition.

[67] After completion of the reaction, the reaction mixture was cooled to 25 0 C and 300 g of a mixture of methylcellosolve, methanol and acetone (1:1:1 v/v/v) was added to adjust the solid content to a proper extent. Additives for surface slip (BYK-310, BYK- Chemie) were also added in an amount of 30 g to afford a base paint resin.

[68] EXAMPLE 3: Preparation of Inorganic Paint Composition

[69] 30 Grams of the urushiol obtained in Example 1 was mixed with 70 g of the base resin obtained in Example 2 and stirred to produce an inorganic paint composition.

[70] EXAMPLE 4: Preparation of Inorganic Paint Composition

[71] An inorganic paint composition was prepared in the same manner as in Example 3, with the exception that a dispersion of colloidal silica (STO-33, Nissan Chemical) in water, instead of a colloidal silica dispersion in alcohol, was used in Example 2.

[72] EXAMPLE 5: Preparation of Inorganic Paint Composition

[73] An inorganic paint composition was prepared in the same manner as in Example 3, with the exception that a mixture of 1 : 1 (w/w) colloidal silica : colloidal zirconia was used in Example 2.

[74] EXAMPLE 6: Preparation of Inorganic Paint Composition

[75] An inorganic paint composition was prepared in the same manner as in Example 3, with the exception that a mixture of 1:0.7:0.3 colloidal silica : colloidal zirconia : colloidal alumina (AS-200, Nissan Chemical) (w/w/w) was used in Example 2.

[76] COMPARATIVE EXAMPLE 1 : Preparation of Inorganic Paint Composition

[77] The same procedure as in Example 3 was repeated with the exception that colloidal silica was not used in Example 2.

[78] COMPARATIVE EXAMPLE 2: Preparation of Inorganic Paint Composition

[79] The same procedure as in Example 3 was repeated with the exception that γ- glycidoxypropyltrimethoxysilane was not used in Example 2.

[80] COMPARATIVE EXAMPLE 3: Preparation of Inorganic Paint Composition

[81] The same procedure as in Example 3 was repeated with the exception that zirconium butoxide was not used in Example 2.

[82] EXPERIMENTAL EXAMPLE 1 : Evaluation of Physical Properties

[83] With the composition prepared in Examples and Comparative Examples, goods made of stainless steel (metals) or tiles (ceramics) were brushed once. As for polycarbonate goods (plastics), it was pre-coated with a primer of urethane resin to improve adhesiveness before brushing with the compositions. A process of brushing and drying were repeated again for wood floors (woods) because they well-absorbed the solutions.

[84] The coatings formed with the inorganic paint composition comprising urushiol in accordance with the present invention were evaluated for physical properties as follows.

[85] 1) Storage stability

[86] This was evaluated as change in viscosity after storage for one month at 25 0 C.

Changes in viscosity were graded as (a) for less than 1, (b) for 1 to 5, (c) for 5 to 10 and (d) for greater than 10, and the results are summarized in Table 1, below.

[87] Table 1

[Table 1] [Table ]

[88] 2) Adhesiveness

[89] A coating film was equally divided into 100 columns with a space of 1 mm and subjected to exfoliation using a 3M cellophane tape according to ASTM D3359. Adhesiveness was evaluated as the number of the columns peeled after 5 rounds of the exfoliation.

[90] 3) Hardness

[91] Using a Mitsubishi pencil, a line of 10 mm length was drawn five times at a speed of

1 cm/sec under a force of 1 kgf on the coating, the state of which was then observed (KS M ISO 15184).

[92] 4) Wear Resistance

[93] The coating was scrubbed 30 times with a 1 kg hammer with #0000 steel wool and evaluated as having no scratches (a), a few scratches (b) and many scratches (c).

[94] 5) Impact Resistance

[95] A 500g steel ball was dropped onto the coating from a height of 50 cm (KS D 6711).

[96] 6) Solvent Resistance

[97] The coating was rubbed 100 times with silicon rubber while being sprayed with alcohols or ketones. The coating was observed for appearance (KS D 9502).

[98] 7) Chemical Resistance

[99] After being immersed for 720 hours in 5% sulfuric acid (acid resistance), 5% sodium carbonate (alkali resistance), 5% sodium hydroxide (base resistance), the coating was observed for exfoliation and swelling (KS M 5307, KS D 6711).

[100] 8) Antifouling Property

[101] 24 Hours after being stained with oil ink, the coating was cleaned with alcohol and observed for contamination (JIS K 5400).

[ 102] 9) Cold and Thermal Resistance

[103] After 20 cycles of incubation for 1 hour at 15O 0 C and -5 0 C each, the coating was observed for exfoliation and swelling (JIS K 5400).

[104] 10) Boiling Water resistance

[105] After being immersed in 100 0 C for 1 hour, the coating was observed for appearance and adhesiveness.

[106] The results of the assay of the paint compositions applied to stainless steel, tile, polycarbonate and wood for physical properties are summarized in Tables 2 to 5, below.

[107] Table 2

[Table 2] [Table ]

Table 3

[Table 3] [Table ]

[109] [HO] Table 4

[Table 4] [Table ]

[111] [112] Table 5

[Table 5] [Table ]




 
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