Anodizing aluminum and alloys thereof

Anodizing Aluminum and Alloys Thereof

<p>The present invention relates to a method for producing a colored oxide layer on an aluminum substrate. In particular, the present invention relates to a method for preparing a colored oxide layer by anodizing an aluminum substrate in an electrolyte comprising water, oxalic acid and sulfuric acid.</p>

<p>Aluminum and aluminum alloys are known to have suitable properties such as light weight, strength, durability and structural flexibility. 1889, Alcoa.<i>Inc</i> As an electrolysis method for manufacturing aluminum from aluminum oxide, the company has obtained a patent (US Pat. No. 400,664) for a method that significantly lowers the manufacturing cost of aluminum through the above process. Since then, due to their suitable properties and low cost, aluminum and aluminum alloys have been widely used in aviation, transportation, construction, semiconductor and electronic industries, and the like. As a result, the widespread use of aluminum exceeds that of all other metals except iron in terms of quantity and price.</p><p>Aluminum metals and alloys are used in watches, computers (such as heat sinks for CPUs), computer-related products (packaging materials for hard drives and flash drives), televisions, radios, refrigerators, air conditioners, and transportation (automobiles, aircraft, trucks, railways). Parts or components of various commodities such as vehicles, marine vessels, bicycles, etc.), packaging materials (cans, foils, etc.), structures (windows, doors, siding, building wires, etc.), cooking utensils, power lines, MKM steel and Alnico magnets, etc. can be used as</p><p>In addition to the suitable properties mentioned above, aluminum metals and alloys may be anodized to improve corrosion resistance, abrasion resistance, electrical insulation, adhesion properties and/or aesthetic properties. In general, anodizing is an electrochemical process that thickens and strengthens a naturally occurring protective oxide layer of aluminum or aluminum alloy. The oxide layer or the anode coating layer prepared according to the process is probably the second highest strength material known to mankind after diamond. The oxide layer usually has a pore structure that can allow for a second implant (organic and inorganic coloring, lubricating acid, etc.) for surface modification.</p><p>Aluminum anodizing processes can include batch, continuous coil, continuous component and basket anodizing. This anodizing process competes with other technologies such as painting, lacquering, and physical vapor deposition (PVD) to form decorative or protective coatings with a variety of color choices, as well as technical advantages not found in these technologies. and the aesthetics of anodizing. For example, painting and lacquering are generally poorly durable and do not comply with the Restriction of Hazardous Substances (RoHS) directive set by the European Union to regulate heavy metals and toxic substances. On the other hand, the PVD process not only does not provide the desired color selectivity in some cases, but also does not satisfy the process stability required for mass production.</p><p>Although various anodizing processes have been developed, there are three main examples of aluminum anodizing: chrome anodizing, sulfuric acid anodizing and hard coat anodizing. Such anodizing processes are also disclosed in S. Kawai, "Anodizing and Coloring of Aluminum Alloys," ASM International (2002), which is incorporated herein by reference.</p><p>Chromium anodizing is commonly referred to as type 1 anodizing. Electrolyte solution at about 40°C with chromic acid, about 0.15 A/dm<sp>2</sp> to 0.45 A/dm<sp>2</sp>The reaction can take place at a current density of The process generally takes about 40 to 60 minutes. Chromium anodizing can produce thin oxide layers, typically 1 to 2.5 microns thick. Because chromic acid is less corrosive than sulfuric acid, chromium anodizing can be used for difficult-to-clean composite parts. Chromium anodizing can reduce the fatigue strength of aluminum compared to other methods described below.</p><p>Sulfuric acid anodizing is called type 2 anodizing. About 1.0 A/dm using an electrolyte solution at about 25°C containing sulfuric acid<sp>2</sp> to 1.5 A/dm<sp>2</sp>The reaction can take place at a current density of The process generally takes about 30 to 60 minutes, depending on the alloy used. Sulfuric acid anodizing can produce oxide layers that are typically about 10 to 14 microns thick. The symbol type 2 above may be used to refer to sulfuric acid anodizing, whereas the symbol class 1 for type 2 may be used to specify that it is a natural color, or not dyed, and class 2 may be used to refer to a dye. have.</p><p> Hard coat anodizing is commonly referred to as type 3 anodizing. Type 3 oxide layers are generally fabricated at very low temperatures and high current densities. For example, type 3 anodizing can be performed in an electrolyte solution containing sulfuric acid at about 0-5° C., and a current density of about 3.5 A/dm.<sp>2</sp> to 4.0 A/dm<sp>2</sp>am. The process generally takes 20 to 120 minutes. Hardcoat anodizing generally produces an oxide layer that is about 30 to 60 microns thick.</p><p> Anodizing processes can provide advantages over other techniques, and can provide decorative oxide layers of one or more colors, with or without dyeing, but anodizing processes such as Type 2 and Type 3 processes have some disadvantages. have For example, the Type 3 anodizing process generally produces a hard, opaque oxide layer, which can be difficult to dye and polish. In addition, the Type 2 anodizing process cannot produce high hardness and/or luster suitable for certain decorative coatings. Moreover, since the type 2 anode oxide layer can be dissolved in the corrosion anodizing bath, the thickness of the type 2 oxide layer can be limited. Corrosion may not affect thicker products, but corrosion may nevertheless weaken the surface, leaving flow marks, teardrops, etched trenches, etc. in the oxide layer. The same surface defects can be created. </p><p> In order to overcome the disadvantages of the above-mentioned painting, lacquering, PVD and conventional anodizing techniques, when applied for decoration and/or protection, the anodized surface to be dyed and mirror finished has excellent hardness and durability There is a need to develop an improved technique for surface treatment of an aluminum substrate to provide this excellent anodized surface.</p>

<solutionproblem><p>Accordingly, the present invention relates to a method for producing a colored oxide layer on an aluminum substrate comprising anodizing the aluminum substrate at two different current densities. Specific examples of the raw material composition to be described below are determined to satisfy the above-mentioned needs.</p></solutionproblem><meansproblemsolution><p> A first invention according to the present invention is a method for producing a colored oxide layer on an aluminum substrate, comprising the steps of (a) disposing an aluminum substrate as an anode in an electrolyte containing water, oxalic acid and sulfuric acid ; and (b) a density of 0.5 A/dm<sp>2</sp> Anodize the aluminum substrate for 1 minute to 1 hour with a first current of less than 1.5 A/dm density<sp>2 </sp>to 2.5 A/dm<sp>2</sp>It relates to a method for producing a colored oxide layer comprising; preparing an oxide layer by anodizing with a second current of</p><p> In some specific examples, the aluminum substrate has a density of 1.0 A/dm<sp>2 </sp>to 1.5 A/dm<sp>2</sp>It can be further anodized with a third current of In another specific example, the first current, the second current, and the third current may be each independently generated by a constant direct current or a pulsed direct current.</p><p> In some specific examples, the manufacturing method may further include agitating the electrolyte through a stirring device. In another specific example, the stirring device may include a stirring tube.</p><p> In one specific example, the method may further include forming a dye layer on the oxide layer. In another specific example, the electrolyte may additionally include aluminum ions, metal sulfates, organic acids, or a combination thereof. In another specific example, the electrolyte may additionally contain 2 g to 11 g of aluminum ions per 1 liter of the electrolyte.</p><p> In one specific example, the electrolyte may include 5 g to 40 g of oxalic acid per liter of electrolyte and 100 g to 360 g of sulfuric acid per liter of electrolyte. In another specific example, the electrolyte may include 12 g to 20 g of oxalic acid per liter of electrolyte and 140 g to 220 g of sulfuric acid per liter of electrolyte. In another specific example, the electrolyte may include 14 g to 18 g of oxalic acid per liter of electrolyte and 160 g to 200 g of sulfuric acid per liter of electrolyte.</p><p> In one specific example, the anodizing step may be performed at a temperature of 5°C to 25°C. In another specific example, the anodizing step may be performed at a temperature of 10 °C to 15 °C.</p><p> In one specific example, the aluminum substrate is aluminum and, optionally, silicon, boron, germanium, arsenic, antimony, tellurium, copper, magnesium, manganese, zinc, lithium, iron, chromium, and an element selected from the group consisting of vanadium, titanium, bismuth, gallium, tin, lead, zirconium, nickel, cobalt, and combinations thereof.</p><p> The present invention also provides an article comprising an aluminum substrate having a colored oxide layer thereon, the colored oxide layer comprising: </p><p> (a) disposing an aluminum substrate as an anode in an electrolyte comprising water, oxalic acid and sulfuric acid; and</p><p> (b) Density 0.8 A/dm<sp>2</sp> Anodize the aluminum substrate for 1 minute to 1 hour with a first current of less than 1.5 A/dm density<sp>2 </sp>to 2.5 A/dm<sp>2</sp>It relates to an article characterized in that it is manufactured through a method comprising; anodizing with a second current of to prepare an oxide layer.</p><p> In one specific example, the colored oxide layer may have a microhardness of 280 to 1000 Hv. In another specific example, the colored oxide layer can be between 15 microns and 50 microns in thickness. In another specific example, the article may further include a dye layer over the oxide layer. In one specific example, the surface of the colored oxide layer may have an Ra value of 0.01 to 0.1 microns.</p></meansproblemsolution>

<p><u>Justice</u></p><p>As used herein, "substantially pure" metal means a metal or alloy substantially free of one or more other elements or compounds, for example greater than 80% by weight, 90% by weight relative to the total weight of the metal or alloy. greater than, greater than 95%, greater than 96%, greater than 97%, greater than 98%, greater than 99%, greater than 99.5%, greater than 99.6%, greater than 99.7%, greater than 99.8% or 99.9% metals or alloys comprising more metals or alloys; or less than 20 wt%, less than 10 wt%, less than 5 wt%, less than 3 wt%, less than 1 wt%, less than 0.5 wt%, less than 0.1 wt%, or less than 0.01 wt% relative to the total weight of the metal or alloy means a metal or alloy containing one or more other elements or compounds of</p><p>As used herein, a metal or alloy that is "substantially free" of an element or compound is less than 20%, less than 10%, less than 5%, less than 4%, or 3% by weight relative to the total weight of the metal or alloy. means a metal or metal alloy comprising less than, less than 2 wt%, less than 1 wt%, less than 0.5 wt%, less than 0.1 wt%, or less than 0.01 wt% of an element or compound.</p><p>As used herein, an alloy refers to a material composed of two or more metals. In general, alloys are designed and manufactured to have certain specific, desired properties, including strength, formability, and corrosion resistance.</p><p>As used herein, Ra refers to an arithmetic mean deviation from an absolute value of a roughness profile measured from an average line or center line, and is known as centerline average roughness (CLA). The centerline divides all areas above it equally with all areas below it.</p><p>As used herein, Rq means the mean square or geometric mean deviation of the roughness profile from the mean line measured over the sample length.</p><p>As used herein, "buffing" or "polishing" refers to a process of polishing a product, such as a metal or alloy, so that it can be polished to a bright, smooth mirror finish.</p><p>In the following detailed description, all numbers disclosed herein represent approximate numerical values, regardless of whether the terms "about" or "approximately" are used in connection therewith. They can vary by 1 percent, 2 percent, 5 percent or sometimes 10 to 20 percent. lower limit R<sp>L</sp> and upper limit R<sp>U</sp>Whenever a range of recited numbers is disclosed, any number falling within that range is deemed specifically disclosed. In particular, the following numbers falling within this range are considered specifically disclosed: R=R<sp>L </sp>+ k*(R<sp>U</sp>- R<sp>L</sp>), where k is a variable in the range of 1 percent to 100 percent differing by 1 percent, for example, k is 1 percent, 2 percent, 3 percent, 4 percent, 5 percent, ... , 50 percent, 51 percent, 52 percent, , 95 percent, 96 percent, 97 percent, 98 percent, 99 percent, or 100 percent. Moreover, the numerical range defined by the two numbers R as defined above is also deemed to be specifically disclosed.</p><p><u>Specific examples for practicing the invention</u></p><p> The present invention provides a method for preparing a colored oxide layer on an aluminum substrate, comprising the steps of: (a) disposing an aluminum substrate as an anode in an electrolyte comprising water, oxalic acid and sulfuric acid; and (b) a density of 0.8 A/dm.<sp>2</sp> Anodize the aluminum substrate for 1 minute to 4 hours with a first current of less than 1.5 A/dm density<sp>2 </sp>to 2.5 A/dm<sp>2</sp>It relates to a method for producing a colored oxide layer comprising; preparing an oxide layer by anodizing with a second current of</p><p> The present invention also provides an article comprising an aluminum substrate having a colored oxide layer thereon, wherein the colored oxide layer is (a) an aluminum substrate in an electrolyte comprising water, oxalic acid and sulfuric acid. disposing as an anode; and (b) a density of 0.8 A/dm.<sp>2</sp> Anodizing the aluminum substrate for 1 minute to 1 hour with a first current of less than 1.5 A/dm density<sp>2 </sp>to 2.5 A/dm<sp>2</sp>It relates to an article manufactured through a method comprising; anodizing with a second current to prepare an oxide layer. In some specific examples, the oxide layer may be a colored oxide layer. In another specific example, the oxide layer may be opaque and colored. Further, in another specific example, the oxide layer may be transparent and colored.</p><p>These items include pens, lighters, watches, computers, computer-related products (hard drives, flash drives, DVD drives, etc.), printers, copiers, fax machines, televisions, radios, refrigerators, air conditioners, transportation means, packaging materials, structures, cooking utensils, It can be made or used as parts or components in various products such as architectural finishing materials and decorative materials, machinery, or in other fields where the decoration of aluminum coated with excellent strength and special physical properties are required.</p><p>Suitable aluminum substrates for the methods and articles may be aluminum metals or known aluminum alloys substantially free of other elements or compounds. While aluminum metal may be suitable for a number of applications, in some cases it may be preferable to use an aluminum alloy because of its improved chemical, physical and mechanical properties over aluminum metal. In general, by mixing aluminum with other elements through a thermo-mechanical process, an aluminum alloy can be produced. A brief historical overview of the alloy and its manufacturing techniques is by Joseph R. Davis"<i>Aluminum and Aluminum Alloys</i>," ASM International, (1993); and RE Sanders, "Technology Innovation in Aluminum Products," <u>The Journal of The Minerals</u>, 53(2), pp. 21-25 (2001), all of which are incorporated herein by reference.</p><p>In general, aluminum alloys exhibit improved mechanical properties, such as high strength:weight ratio, especially when the alloy is tempered. A large amount of metal material is broadly referred to as "aluminum", but in fact, many of them are replacing aluminum alloys. For example, most aluminum foils consist of an alloy comprising 92% to 99% by weight aluminum.</p><p>In one specific example, the aluminum substrate substantially comprises other elements such as copper, zinc, magnesium, manganese, silicon, lithium, iron, chromium, vanadium, titanium, bismuth, gallium, lead, zirconium, and combinations thereof. It can be aluminum metal that does not do. In one specific example, the aluminum substrate comprises greater than 95 weight percent aluminum, greater than 96 weight percent aluminum, greater than 97 weight percent aluminum, greater than 98 weight percent aluminum, greater than 99 weight percent aluminum, based on the total weight of the aluminum substrate. of aluminum, greater than 99.5 weight percent aluminum, greater than 99.9 weight percent aluminum, or greater than 99.99 weight percent aluminum. In one specific example, the aluminum substrate may include 99% by weight or more of aluminum based on the total weight of the aluminum substrate. The aluminum may include 1000 series aluminum metal, for example, 1060 and 1100 listed in Table 1, but is not limited thereto.</p><p>In another specific example, the aluminum substrate may be an aluminum alloy. Aluminum can readily form alloys with semimetals, metals, and combinations thereof. The semimetal may be silicon, boron, germanium, arsenic, antimony, telluride, or the like, but is not limited thereto. The metal may be copper, zinc, magnesium, manganese, lithium, iron, chromium, vanadium, titanium, bismuth, gallium, lead, zirconium, etc., but is not limited thereto. In general, copper can increase strength, hardness and heat-treatability. Magnesium can increase tensile strength, resistance to seawater corrosion, weldability and hardness. Manganese can increase strength and resistance to corrosion. Silicone can lower the melting point and improve castability; Zinc can increase the strength and hardness of the alloy.</p><p>There are a variety of aluminum alloys that are classified according to many different entities. For example, commonly used aluminum alloy compositions are registered with the 'Aluminum Association'. On the other hand, many other organizations, including the 'Society of Automotive Engineers Standards Organization' and 'ASTM', are presenting more specific standards for the production of aluminum alloys. Alternatively, aluminum alloys may be classified by a number system (eg ANSI) or by designation including their predominant alloy composition (eg DIN and ISO).</p><p>The aluminum alloy as used herein may include a non-aluminum component comprising aluminum and at least one or more semimetals and other metals. In some specific examples, the semimetals and other metals are silicon, boron, germanium, arsenic, antimony, tellurium, copper, magnesium, manganese, zinc, lithium, iron, chromium, vanadium, titanium, bismuth, gallium, tin, lead. , zirconium, nickel, cobalt, and combinations thereof. In one specific example, the aluminum alloy comprises greater than 85 weight percent aluminum, greater than 87 weight percent aluminum, greater than 90 weight percent aluminum, greater than 92 weight percent aluminum, greater than 93 weight percent aluminum, and greater than 94 weight percent aluminum, based on the weight of the aluminum alloy. % greater than 95% aluminum by weight. In one specific example, the aluminum alloy is greater than 1 wt%, greater than 2 wt%, greater than 3 wt%, greater than 4 wt%, greater than 5 wt%, greater than 6 wt%, greater than 7 wt%, based on the total weight of the aluminum alloy. It may contain more non-aluminum elements.</p><p>In another specific example, the aluminum alloy may be an alloy including aluminum and copper. In one specific example, the aluminum alloy comprises greater than 1 weight percent copper, greater than 2 weight percent copper, greater than 3 weight percent copper, greater than 4 weight percent copper, greater than 5 weight percent copper, and greater than 6 weight percent copper, based on the total weight of the aluminum alloy. excess, greater than 7 weight percent copper.</p><p>In another specific example, the aluminum alloy may be an alloy including aluminum and magnesium. In one specific example, the aluminum alloy comprises greater than 1 wt% magnesium, greater than 2 wt% magnesium, greater than 3 wt% magnesium, greater than 4 wt% magnesium, greater than 5 wt% magnesium, and greater than 6 wt% magnesium, based on the total weight of the aluminum alloy. excess, greater than 7% by weight magnesium. In some specific examples, the aluminum alloy may be substantially free of magnesium.</p><p>In another specific example, the aluminum alloy may be an alloy including aluminum and manganese. In one specific example, the aluminum alloy comprises more than 1 wt% manganese, more than 2 wt% manganese, more than 3 wt% manganese, more than 4 wt% manganese, more than 5 wt% manganese, 6 wt% manganese, based on the total weight of the aluminum alloy excess, greater than 7% by weight manganese. In another specific example, the aluminum alloy may include substantially no manganese.</p><p>In another specific example, the aluminum alloy may be an alloy including aluminum and silicon. In one specific example, the aluminum alloy comprises more than 1 wt% silicon, more than 2 wt% silicon, more than 3 wt% silicon, more than 4 wt% silicon, more than 5 wt% silicon, more than 6 wt% silicon, based on the total weight of the aluminum alloy excess, greater than 7 weight percent silicone. In another specific example, the aluminum alloy may be substantially free of silicon.</p><p>In another specific example, the aluminum alloy may be an alloy including aluminum and zinc. In one specific example, the aluminum alloy comprises greater than 1 weight percent zinc, greater than 2 weight percent zinc, greater than 3 weight percent zinc, greater than 4 weight percent zinc, greater than 5 weight percent zinc, and greater than 6 weight percent zinc, based on the total weight of the aluminum alloy. excess, greater than 7% by weight zinc. In another specific example, the aluminum alloy may be substantially free of zinc.</p><p>In another specific example, the aluminum alloy may be an alloy including aluminum and tin. In one specific example, the aluminum alloy comprises greater than 1 weight percent tin, greater than 2 weight percent tin, greater than 3 weight percent tin, greater than 4 weight percent tin, greater than 5 weight percent tin, and greater than 6 weight percent tin, based on the total weight of the aluminum alloy. excess, greater than 7% by weight of tin. In another specific example, the aluminum alloy may be substantially free of tin.</p><p>In one specific example, an aluminum alloy suitable for forming the oxide layer described herein may be a machined aluminum alloy. In general, machined aluminum contains four numbers to identify the alloying element, followed by a dash: -, a letter that is distinguished by the type of heat treatment, and an example of a number from 1 to 4 that is distinguished by a certain degree of annealing. For example, it can be classified as 6061-T6, which is a commonly used free-machining aluminum alloy. The physical properties of the aluminum alloy may be affected by heat treatment and a certain degree of annealing.</p><p>Suitable wrought aluminum alloys and their compositions are disclosed in Table 1, but are not limited thereto.</p><p>[Table 1] Worked alloy composition classification (wt%)</p><p><img file="KR20080098331A_D0001.tif" /></p><p><img file="KR20080098331A_D0002.tif" /></p><p><img file="KR20080098331A_D0003.tif" /></p><p>Any engineered aluminum alloy known to those skilled in the art may be suitable for forming the oxide layer described herein. In one specific example, the aluminum alloy may be one of a 2000 series, 3000 series, 4000 series, 5000 series, 6000 series, or 7000 series alloy. In general, the major non-aluminum alloy constituents used in 1000 series, 2000 series, 3000 series, 4000 series, 5000 series, 6000 series, or 7000 series aluminum alloys are copper, manganese, silicon, magnesium, magnesium/silicon and respectively It may be zinc. Suitable working aluminum alloys may include, but are not limited to, the alloys shown in Table 1, 2011, 2017, 4032, 5005, 6061, and the like.</p><p>In another specific example, each of the 1000 series, 2000 series, 3000 series, 4000 series, 5000 series, 6000 series, or 7000 series aluminum alloys may be heat treated, thus resulting in temper code designation F, described below; It may be one of O, T or H.</p><p>The symbol "F" is manufactured without any special treatment such as casting, hot working or cold working in heat treatment or strain hardening after shaping process ( fabricated) as it is.</p><p>The symbol "O" means annealed alloy. It has the lowest strength and the highest ductility temper.</p><p>The symbol "T" refers to an alloy strengthened by heat treatment, with or without continuous strain hardening treatment. The T quality code is as follows.</p><p>T1 Substantially stable after a high temperature shaping process followed by cooling and natural aging.</p><p>T2 Formed at elevated temperatures, then cooled, cold treated, and then naturally aged to substantially stabilize.</p><p>T3 solution heat treatment, cold working, natural aging treatment, substantially stable state.</p><p>T4 solution heat treatment, then natural aging treatment to substantially stabilize.</p><p>T5 Formed at high temperature, then cooled and artificially aged.</p><p>T6 Solution heat treatment and artificial aging.</p><p>After T7 solution heat treatment, it was stabilized by overaging.</p><p>T8 Solution heat treated, then cold worked, and artificially aged.</p><p>T9 Solution heat treatment, artificial aging, and cold working.</p><p>T10 Formed at high temperature, cold worked and artificially aged.</p><p>The symbol "H" means an alloy strengthened by strain hardening without successive heat treatment or heat treatment. The strain hardening codes for each H quality are as follows.</p><p>H1 Strain hardening only.</p><p>H2 strain hardened and partially annealed.</p><p>H3 strain hardened and stabilized.</p><p>H4 Strain hardened, lacquered or painted. This takes into account that temperature effects in the coating process can affect strain hardening; It doesn't happen often.</p><p>In one specific example, an aluminum alloy suitable for forming the oxide layer described herein may be a cast aluminum alloy. In general, cast aluminum alloys can be identified by a number of 4 to 5 digits written with a breakpoint. The number in the hundredth place refers to the alloy element, while the number after the dividing point refers to the form (cast form or ingot). For example, cast alloys include x1xx.x series containing at least 99% aluminum; x2xx.x series with copper; x3xx.x series with silicon, copper and/or magnesium; x4xx.x series with silicon; x5xx.x series containing magnesium; x7xx.x series with zinc; x8xx.x series with annotations; x9xx.x series containing various metals; may include. Suitable wrought aluminum alloys may be, but are not limited to, 355, 356, 357, 360, 380, 319, and the like.</p><p>In one specific example, the aluminum alloy suitable for forming the oxide layer described herein may be a known aluminum alloy. The known aluminum alloys include Al-Li alloy (alloy of aluminum and lithium), Duralumin (alloy of aluminum and copper), Nambe (alloy of aluminum and seven other undisclosed metals), Magnox (alloy of aluminum and magnesium) ), Zamak (alloy of aluminum, zinc, magnesium and copper), Silumin (alloy of aluminum and silicon), and AA-8000.</p><p>The anodizing method described herein may generally include at least three treatment steps, for example, pretreatment, anodizing and posttreatment. Any pretreatment process known to those skilled in the art can be used to pretreat the surface of the aluminum substrate prior to the anodizing step. Suitable pretreatment processes include cleaning the surface by mechanical and/or chemical means, treating the surface by corona discharge, flame, plasma, alkaline and/or acid etching and combinations thereof. may include, but is not limited thereto. In some specific examples, the surface of the aluminum substrate may be first cleaned and then chemically treated or etched. The washing may be performed by known mechanical means, chemical means, or a combination thereof. Cleaning may include, but is not limited to, using a solvent in a degreasing process and using mechanical stirring or ultrasonic vibration to remove oil and particulates on the surface. .</p><p>Optionally, the cleaned surface may be chemically treated continuously with a non-etching alkaline solution, preferably at a high temperature, to further remove contaminants. In addition, the cleaned surface may be etched with an aqueous solution of an inorganic acid, a strong organic acid, or a combination thereof. Suitable inorganic acids can be, but are not limited to, sulfuric acid, nitric acid, hydrochloric acid, hydrofluoric acid, hydrobromic acid, hydroiodic acid, phosphoric acid, and combinations thereof. Suitable strong organic acids can be, but are not limited to, p-toluenesulfonic acid, trifluoroacetic acid, 4-(trifluoromethyl)benzoic acid, methanesulfonic acid, acetic acid, and combinations thereof. The etching acid solution is a metal dichromate (eg lithium dichromate, sodium and potassium) or a metal permanganate (eg lithium permanganate, sodium and potassium), a peroxide (eg hydrogen peroxide) and combinations thereof, but is not limited thereto.</p><p>In general, varying degrees of etching (eg, weak, medium, strong) can be controlled by varying the time and temperature of the etching process. The etching time may vary from about 1 minute to 4 hours, from about 10 minutes to 2 hours, and from about 15 minutes to 1 hour. The etching temperature may range from about 20°C to 90°C, from about 25°C to 80°C, from about 30°C to 75°C, or from about 30°C to 60°C. The degree of etching can generally be increased by increasing the etching time, increasing the etching temperature, or a combination thereof.</p><p>In one specific example, the surface of the aluminum substrate may be pretreated by a Forest Product Laboratories (FPL) etching process. The FPL process generally comprises the following steps;</p><p>1) removing oil and particulates using a solvent such as hydrocarbon and halogenated hydrocarbon (eg, trichloroethylene); </p><p>2) an alkali cleaning step of further removing contaminants by immersing the aluminum substrate in a non-etching alkali solution at 50° F. to 140° F.;</p><p>3) etching the aluminum substrate by infiltration in sulfuric acid and aqueous sodium dichromate solution for 9-15 minutes;</p><p>4) a washing step of washing the aluminum substrate with water at 50° C. or less for about 1 to 2 minutes;</p><p>5) A drying step in which the aluminum substrate is air-dried at less than 65° C. for one hour.</p><p>In another specific example, the surface of the aluminum substrate may be pretreated by a phosphoric acid anodize (PAA) etching process. The PAA etch process is an FPL etch process, except that the PAA etch process typically involves an anodizing process where a bias of about 10V is applied through a stainless steel anode to form an excellent anode layer on the product. similar to</p><p>Optionally, the surface of the aluminum substrate may be brightened by pretreating the surface with a concentrated mixture of phosphoric acid and nitric acid that chemically polishes the surface of aluminum. In some specific examples, a near mirror finishing may be produced.</p><p>In the anodizing step, the aluminum substrate may be infiltrated into a bath containing an electrolyte, while an electric current may pass through the bath to generate an oxide layer on the surface of the aluminum substrate. The oxide layer is mainly derived from the aluminum substrate itself, not from the electrolyte. Depending on the aluminum substrate, the oxide layer may be transparent, opaque or colored. Moreover, the oxide layer may be dyed simultaneously or sequentially in one or more suitable colors suitable for various decorative and/or protective applications.</p><p>The aqueous electrolyte generally includes water, sulfuric acid and oxlic acid. Any commercially available sulfuric acid may be used. The amount of the sulfuric acid may be about 100 g to 360 g, about 140 g to 220 g, about 160 g to 200 g, per liter of electrolyte. Any commercially available oxalic acid may be used. The amount of the oxalic acid may be about 5 g to 40 g, about 12 g to 20 g, or about 14 g to 18 g per liter of electrolyte. In some specific examples, the electrolyte may include about 160 g to 200 g of sulfuric acid per liter of electrolyte and about 14 g to 18 g of oxalic acid per liter of electrolyte.</p><p>Optionally, the electrolyte may further include an aluminum ion, metal sulfate, an organic acid other than oxalic acid, a metal carboxylate, or a combination thereof. In one specific example, the electrolyte may include aluminum ions. The amount of the aluminum ions may be about 0.5 g to 30 g, about 1 g to 20 g, or 2 g to 11 g per liter of electrolyte. In another specific example, the electrolyte may include an organic acid other than metal sulfate, oxalic acid, or a metal salt of an organic acid. The amount of each of the metal sulfate, the organic acid and the metal carboxylate may be 0 to 100 g per 1 liter of the electrolyte. In one specific example, the electrolyte may be substantially free of an organic acid other than metal sulfate, oxalic acid, or metal carboxylate.</p><p>The metal sulfate may be lithium, sodium, potassium, copper, magnesium, manganese, silicon, zinc, iron, chromium, vanadium, titanium, bismuth, gallium, tin, lead, zirconium, nickel, cobalt or their combinations of sulfates. Suitable examples of such organic acids include saturated aliphatic alpha-hydroxy monocarboxylic acids (e.g. glycolic acid, lactic acid and malic acid) and saturated and unsaturated aliphatic dicarboxylic acids other than oxalic acid (e.g. horse ronic acid, succinic acid and maleic acid), but are not limited thereto. The metal of the metal carboxylate may be lithium, sodium, potassium, copper, magnesium, manganese, silicon, zinc, iron, chromium, vanadium, titanium, bismuth, gallium, tin, lead, zirconium, nickel or cobalt. The carboxylate may be derived from saturated and unsaturated aliphatic dicarboxylic acids, including saturated aliphatic monocarboxylic acids, saturated aliphatic alpha-hydroxy mono carboxylic acids and oxalic acids, or combinations thereof.</p><p>The temperature of the anodizing bath may be about 5 to 25 or about 10 to 15 . The anodizing step is 0.8 A/dm in the first period<sp>2</sp> Less than 0.7 A/dm<sp>2</sp> less than 0.6 A/dm<sp>2</sp> less than or 0.5 A/dm<sp>2</sp> At a first current density of less than about 1.5 A/dm in a second period<sp>2 </sp>to 2.5 A/dm<sp>2</sp>, about 1.6 A/dm<sp>2 </sp>to 2.4 A/dm<sp>2</sp>, about 1.7 A/dm<sp>2 </sp>to 2.3 A/dm<sp>2</sp>can be done in The first period of time may be from about 0 to 10 hours, from about 0.5 minutes to about 5 hours, or from about 1 minute to about 1 hour. The second period of time may be from about 1 minute to about 5 hours, from about 5 minutes to about 1.5 hours, or from about 5 minutes to about 45 minutes. The anodizing step is about 0.5 A/dm in the third period<sp>2</sp> to about 2.0 A/dm<sp>2</sp>, about 0.75 A/dm<sp>2 </sp>to about 1.75 A/dm<sp>2</sp> or about 1.0 A/dm<sp>2</sp> to about 1.5 A/dm<sp>2</sp>It may further include using a third current density of . The third period of time may be from about 1 minute to about 5 hours, from about 1 minute to about 2 hours, or from about 1 minute to about 30 minutes.</p><p>In order to maintain the current density in the above specific range, it is necessary to gradually increase the applied voltage between the electrodes from about 10V to 250V over time, depending on the thickness of the oxide layer formed on the aluminum substrate. In one specific example, the applied voltage may be increased from about 10V to 200V, from about 15V to 150V, or from about 20V to 100V, so that the current density may be maintained in a constant or specific range. The anodizing step described herein is a constant direct current or pulsed direct current, a rectified pulsed direct current, an alternative current, a rectified alternative current, or Combinations of these may be used.</p><p>Optionally, the electrolyte may be stirred or cooled by a stirring device or a cooling device to remove heat formed on the surface of the aluminum substrate during the anodizing step. Efficient control of the electrolyte temperature can generally stabilize the coating quality and improve the physical properties of the coating. In some specific examples, the stirring device is, for example, a mechanical mixing device such as a stirrer, mixer and homogenizer or an ultrasonic vibrator or circulation of electrolyte around the surface of an aluminum substrate. It may be a mixer that can promote</p><p>In another specific example, the stirring device may include one or more stirring tubes having holes having a diameter of about 5 to 50 microns (μm), about 10 to 40 microns, or about 15 to 25 microns. By allowing air to pass through the holes, very fine air bubbles can form on or near the surface of the aluminum substrate. The air bubble may transfer thermal energy generated on the surface of the aluminum substrate to a relatively cold electrolyte.</p><p>In the post-treatment step, dyeing or coloring, sealing, polishing, or a combination thereof may be performed on the porous anode oxide layer. In some preferred embodiments, the oxide layer may be dyed prior to sealing to form a dye layer thereon. Here, inorganic and organic dyes or colorants suitable for dyeing or coloring the anode oxide layer can be used. 1 shows the pores 2 of an anode cell 1 of an anode oxide present on an aluminum substrate 3 . In one specific example, the diameter of the pores may be 0.005 to about 0.05 microns or 0.01 to about 0.03 microns. In another specific example, the particle size of the dyed or colored molecule may be about 5 nm to 60 nm or 15 nm to 30 nm. The dyeing or coloring may be carried out by any dyeing or coloring method known to those skilled in the art that allows the colorant or dye to enter or accumulate in the pores of the anode cell to form a dye layer.</p><p>Some organic and inorganic dyes are, for example, "<i>Anodizing and Coloring of Aluminum Alloys</i>" by S. Kawai ASM International (2002), which is incorporated herein by reference. Organic dyes include acid dyes, acid metal complexes dyes, acid medium dyes. , direct dyes, week acid dyes, disperse dyes, dissolved reductive dyes, active dyes, alkaline dyes and dissolved in alcohol It may be, but not limited to, a solvent dye such as a dye to be used, a dye soluble in oil, etc. The inorganic dye is described in Table 2 below, but is not limited thereto. It is listed in Table 2.</p><p>[Table 2]</p><p><img file="KR20080098331A_D0004.tif" /></p><p><img file="KR20080098331A_D0005.tif" /></p><p><img file="KR20080098331A_D0006.tif" /></p><p><img file="KR20080098331A_D0007.tif" /></p><p><img file="KR20080098331A_D0008.tif" /></p><p>In general, dyeing or coloring can be accomplished by one of the following methods. In the electrolyte coloring after anodizing, the product may be impregnated with an electrolyte bath containing an inorganic metal salt. An electric current may then be applied to accumulate a metal salt at the base of the anode cell pores. The color that appears generally depends on the metal used and the processing conditions. Moreover, the range of colors can be extended by overstaining with organic dyes. Suitable metals may be, but are not limited to, tin, cobalt, nickel and copper.</p><p>Integral coloring can be formed by combining anodizing and coloring to simultaneously color oxide cell walls with different colors and shapes, such as bronze and black shades. In general, monolithic coloring is more resistant to abrasion than conventional anodizing. This can be one of the most expensive processes, as it requires significantly more power.</p><p>Organic dyes can be used to produce a variety of colors. Organic dyes can provide intensely intense colors that may not match other paint systems commonly used. In general, they can provide good weather fastness and light fastness. The range of colors can be extended by overstaining the electrolyte colors with organic dyes for a wider range of colors and shades. This method is relatively inexpensive and requires minimal upfront capital than any other coloring process.</p><p>Interference coloring may include modification of the pore structure prepared in an electrolyte containing sulfuric acid. Pore expansion may occur at the pore base. The accumulation of metals at these locations can produce numerous light-fast colors ranging from blue, green, and yellow to red. The colors are generally induced by light interference effects rather than by light scattering, as in the basic electrolyte coloring process.</p><p>In some specific examples, organic dyes can be used to fill the pores of the anode oxide layer with color. In another specific example, inorganic dyes or metal salts can accumulate electrochemically at the base of the pores to produce a broad spectrum of colors. In another specific example, a metal (eg, tin) may electrically accumulate in the pores of the anode oxide layer to provide color. In one specific example, the color can be formed integrally with or within the oxide layer by adding a certain organic acid to the sulfur electrolyte during the anodizing process and using a pulsed current. The color of the oxide layer is red, orange, yellow, green, blue, indigo, purple, pink, silver, gold, bronze, brown, black, gray, pale champagne, white and all known shades and shades thereof. (tint), but is not limited thereto.</p><p> After dyeing, the surface of the oxide layer may be selectively sealed by a method known to those skilled in the art in sealing the anode oxide layer. In general, sealing closes the voids in the anode cell, which can provide the surface with resistance to staining, abrasion, craze and color degradation. Moreover, sealing may reduce or eliminate staining and may increase corrosion resistance. In some specific examples, the sealing may be achieved by infiltrating in a salt consisting of a nickel salt, a cobalt salt, and combinations thereof at 20° C., through which the pore may be closed with the salt. In another specific example, the sealing may be performed by converting the oxide to its hydrate form using hot water or steam. This transformation reduces the size of the pores of the anode cell, and as the oxide expands, it can also reduce the pores on the surface. In another specific example, the sealing may be performed in the presence of a metal dichromate such as sodium dichromate. In one specific example, the sealing may be performed in the presence of a metal acetate such as nickel acetate or other anti-bloom agent.</p><p> After sealing, the surface of the oxide layer may be optionally polished or buffed by a polishing or buffing method known to those skilled in the art. In one specific example, the surface of the oxide layer may be buffed or polished by a buffing or polishing compound. The buffing or polishing compound may generally include abrasive particles, a binder and optional additives. The buffing or polishing compound may further include diluent particles such as marble, gypsum, flint, silica, iron oxide, aluminum silicate, and glass (including glass bubbles and glass beads). The buffing or polishing compound may be in the form of a cake, tube, paste, or liquid. The polishing compound or the buffing compound may include, but is not limited to, Rhone-Poluenc Co., France's Opaline gloss compound, and Formax Manufacturing Corp., Grand Rapids, MI's Tripoli compound. .</p><p> Known conventional abrasive particles can be used to buff or polish the compound. Suitable abrasive particles include fused aluminum oxide (including white fused alumina, heat treated aluminum oxide and brown aluminum oxide), silicon carbide (including green silicon carbide), boron carbide, titanium carbide, diamond, cubic boron nitride, garnet, tripoli (microcrystalline SiO)<sb>2</sb>), chromium oxide, cerium oxide, molten alumina-zirconia, sol-gel-derived abrasive particles, and combinations thereof. Any conventional buffing compound binder can be used to buff or polish the compound. Suitable binders may be, but are not limited to, natural waxes, synthetic waxes, chlorinated waxes such as tetrachloronaphthalene, pentachloronaphthalene and polyvinylchloride, and combinations thereof.</p><p> Conventionally known abrasive additives may be used to buff or polish the compound. Suitable additives include pigments such as titanium dioxide or iron oxide, emulsifiers, surfactants, wetting agents, foam stabilizers, thermal or UV stabilizers, antioxidants, grinding aids ( grinding aids) and combinations thereof, but are not limited thereto. The grinding aid is an organic halide such as sodium chloride, potassium cryolite, sodium cryolite, ammonium cryolite, potassium tetrafluoroborate, sodium tetrafluoroborate, silicon fluoride, potassium chloride and magnesium chloride. an organic halide compound, and a halide salt.</p><p> In some specific examples, buffing may be via a rotating buffing wheel filled with a buffing compound in contact with the surface of the product. In another specific example, buffing may be accomplished in two steps, eg, cutting and coloring. The cutting step may be a pretreatment step performed by widely cutting the abrasive buffing compound. For example, the cutting step may be a step necessary to ensure a desired surface finish or smoothness. The coloring step may generally include light-duty buffing to make the surface of the product glossy. Optionally, coloring compounds may be used. Certain coloring compounds may be formulated into abrasives with a finer mesh size than those used for the buffing compound in the cutting step. In one preferred specific example, the same double-duty buffing compound may be used in both the cutting and coloring steps.</p><p> In some specific examples, the buffing compound may be in the form of a liquid or paste. The abrasive particles and binder used to formulate the liquid or paste buffing compound may generally be the same as those used in the solid buffing compound. The components of the liquid or paste buffing compound may consist of an aqueous base and an emulsified fluid to be applied in the form of a spray or brush.</p><p> In one preferred specific example, the buffing may be done through a buffing wheel. Buffing wheels generally perform two main functions. The first is to transport the abrasive particles to the surface of the product to perform cutting and/or coloring. The second can, if necessary, generate enough frictional heat to flow plastically or to give the surface of the product a gloss. Buffing wheels suitable for polishing or buffing processes may be within the scope of designs, buffing structures and designs known to those skilled in the art.</p><p> In another specific example, the surface of the oxide layer may be polished with an abrasive slurry, an abrasive compound, or an abrasive product such as a known fine abrasive wheel or abrasive paper. In some specific examples, the surface of the oxide layer may be polished or buffed by a conventionally known micro-finishing product such as a lapping film. In one specific example, the lapping film may comprise an abrasive product of 400 grit or finer size. In one specific example, the surface of the oxide layer has an Ra value of less than 0.1 microns, less than 0.09 microns, less than 0.08 microns, less than 0.07 microns, less than 0.06 microns, less than 0.05 microns, less than 0.04 microns, less than 0.03 microns, less than 0.02 microns. or less than 0.01 microns. The flatness of the surface can be measured by the following profilometry method.</p><p> The surface roughness of the oxide layer may be measured using a Talysurf PGI 1240 Aspherics Measuring System in Taylor Hobson, Leicester, UK. The gauge distance may be about 10 mm, about 5 mm, about 1 mm, about 0.5 mm, about 0.25 mm, or about 0.1 mm on a straight line. The probe speed for measurement may be about 5 mm/s, about 1 mm/s, about 0.5 mm/s, about 0.25 mm/s, or about 0.1 mm/s.</p><p> In one specific example, the oxide layer has a microhardness measured by the method described herein of about 280 to 1000 Hv, about 280 to 750 Hv, about 300 to 550 Hv, about 320 to 520 Hv, or about It may be 320 to 500 Hv. In one specific example, the microhardness can be measured by a Buehler Micromet 2103 with a Vickers diameter (square base) indenter with a 136 degree angle. In one specific example, the microhardness may be measured by a conventional microhardness measurement method known to those skilled in the art.</p><p> In some specific examples, the oxide layer can be from about 15 microns to 100 microns, from about 15 microns to 75 microns, from about 15 microns to 50 microns, from about 15 microns to 40 microns, or from about 15 microns to 30 microns. In one specific example, the thickness may be measured by a Fischer Isoscope MP30E coating thickness tester.</p><p> The method described herein can be used for batch anodizing and can be used for continuous coil anodizing. Batch anodizing may generally include racking components, and may impregnate them in a series of treatment tanks. Parts suitable for batch anodizing include extrusion, sheet or bent metal parts, castings, cookware, cosmetic cases, flashlight bodies and machining. It may be, but is not limited to, machined aluminum parts.</p><p> Continuous coil anodizing generally involves the continuous unwinding of an already wound coil through a series of anodizing, etching and tank cleaning, and then may include rewinding the anodized coil for marine and structural use. This method is suitable for bulky sheets, foils and non-finished products such as lighting fixtures, reflectors, louvers, spacer bars for insulating glass and continuous roofing systems. can be used</p><p><u>Example</u></p><p> The present invention has been specifically described with reference to the following examples, but these examples do not limit the scope of the present invention.</p><p><u>Example 1</u></p><p> Example 1 was prepared by anodizing an aluminum alloy Al-6063 product in an electrolyte bath containing water, sulfuric acid (180 g per 1 liter of electrolyte) and oxalic acid (electrolyte 16 g/liter) at a temperature of about 10 to 16 °C. This anodizing process consisted of four successive steps, each with a different current density and electrolysis time. The current density of the first stage is 0 to 0.7 A/dm for 10 minutes<sp>2</sp>It was. The current density of the second stage is 0.7 to about 2.0 A/dm for 10 minutes.<sp>2</sp>It was. The current density of the third stage is 2.0 to 2.5 A/dm for 10 minutes<sp>2</sp>It was. The current density of the fourth stage is 1.5 to 2.5 A/dm for 50 minutes<sp>2</sp>It was. The current density was generated by pulsed direct current with a voltage potential of about 20V to 24V. The first, second and third pulse current sequences were turned on for 0.8 s and turned off for 0.2 s. The fourth pulsed current sequence was turned on for 0.6 s and turned off for 0.4 s.</p><p><u>Example 2</u></p><p> Example 2 was prepared in the same manner as in Example 1 except that the product was dyed blue.</p><p><u>Example 3</u></p><p> Example 3 was prepared similarly to the procedure of Example 1, except that the product was dyed red.</p><p><u>Comparative Example A</u></p><p> Aluminum alloy Al-6063 product in an electrolyte bath containing water and sulfuric acid (180-200 g per 1 liter of electrolyte) at a temperature of about 24°C, a direct current of about 12-22V and a current density of about 1.0 A/dm<sp>2</sp>Comparative Example A was prepared by anodizing for 15 minutes under the conditions of</p><p><u>Comparative Example B</u></p><p> Aluminum alloy Al-6063 product in an electrolyte bath containing water and sulfuric acid (180-200 g per 1 liter of electrolyte) at a temperature of about 24°C, a direct current of about 12-22V and a current density of about 1.0 A/dm<sp>2</sp>Comparative Example B was prepared by anodizing under the conditions of 45-60 minutes.</p><p><u>Comparative Example C</u></p><p> Comparative Example C was prepared by coating an aluminum alloy Al-6063 product with diamond-like carbon using a physical vapor deposition technique. This process lasted 2-2.5 hours. The thickness of the diamond-like carbon coating was about 1 micron. The interface was chromium.</p><p><u>Comparative Example D (Type 2 Anodizing)</u></p><p> Aluminum alloy Al-6063 product in an electrolyte bath containing water and sulfuric acid (190-200 g per 1 liter of electrolyte) at a temperature of about 18-20 °C, a direct current of about 15-17 V and a current density of about 1.5 A/dm<sp>2</sp>Comparative Example D was prepared by anodizing under the conditions of 45-60 minutes.</p><p><u>wear test</u></p><p> The abrasion resistance of Comparative Examples AC and Example 1 was tested. The wear test was performed using a Taber Abrasive Wearing tester according to the ISO5470-1 process using the CS-17 abrasive head direction under the loading condition of 1Kg. The wear test was performed with the suction turned on and at a speed of 40 rpm. The thickness of the oxide layer was measured by a Fischer Coating thickness tester. The wear test results are shown in Table 3 below. The results in Table 3 show that Example 1 has better wear resistance than Comparative Example AC.</p><p>[Table 3] Wear test results</p><p><img file="KR20080098331A_D0009.tif" /></p><p><u>coating microhardness test</u></p><p> The microhardness of Comparative Example D and Example 1 was measured. The microhardness tester used a Buehler Micromet 2103 with a Vickers diameter (square base) presser with a 136 degree angle. Comparative Example D and Example 1 were cross-sectioned, plastic mounted, and polished prior to measurement. The load for the microhardness test was 300 gf for Example 1, and 500 gf for Comparative Example D. The microhardness test results are shown in Tables 4 and 5 below. The data in Tables 4 and 5 show that Example 1 has superior average microhardness compared to Comparative Example D.</p><p>[Table 4] Microhardness test results of Example 1</p><p><img file="KR20080098331A_D0010.tif" /></p><p>[Table 5] Microhardness test result of Comparative Example D</p><p><img file="KR20080098331A_D0011.tif" /></p><p> The surface roughness of Examples 2 and 3 was measured by a Taylsurf PGI 1240 Aspherics measuring system in Taylor Hobson, Leicester, UK. The gauge distance was 0.25 mm. The probe speed for the measurement was 0.5 mm/s. An ISO type filter was used. Each sample was measured in both east-west and south-north directions. The surface roughness measurement results of Examples 2 and 3 are shown in Table 6 below.</p><p>[Table 6]</p><p><img file="KR20080098331A_D0012.tif" /></p><p> As mentioned above, specific examples of the present invention provide various methods for preparing colored oxide layers for decorative applications. Although the invention has been described with reference to a relatively limited number of embodiments, specific features shown in one embodiment do not affect other embodiments of the invention. In some specific examples, the methods may include numerous steps not mentioned herein. In other embodiments, the method may not include steps not listed herein or may be substantially free of steps not listed herein. The method for producing the colored oxide layer described herein is described with reference to a number of steps. These steps may be performed in any order. One or more steps may be omitted or combined, but still achieve substantially the same result. The written claims are intended to cover all changes and modifications falling within the scope of the present invention.</p><p> All publications and patent applications mentioned herein are hereby incorporated by reference to the same extent as if each individual publication or patent application specifically and individually referred to was incorporated by reference. Although the present invention has been described in detail through specific descriptions and examples for clear understanding, it is apparent that those skilled in the art to which the present invention pertains can change and modify the present invention within the scope or scope of the present invention. will do</p>