Systems and methods for treating metal substrates

Abstract

A conversion composition containing trivalent chromium cations in an amount of 0.001 g / L to 20 g / L is disclosed. Also disclosed is a system for treating a metal substrate comprising a conversion composition and a sealing composition comprising lithium cations. Also disclosed is a method of treating a metal substrate, the method comprising contacting at least a portion of a surface of the substrate with a conversion composition and then contacting at least a portion of the surface of the substrate with a sealing composition. Substrates obtainable by treatment with this system and / or by treatment methods are also disclosed.

Description

[0001] This application is a divisional application of a Chinese patent application with an application date of August 14, 2017, an application number of 201780049437.6, and an invention title of "Systems and Methods for Treating Metal Substrates".

[0002] Cross - reference to related applications

[0003] This application claims the priority of U.S. Provisional Application No. 62 / 374,188, entitled "Sealing Composition", filed on August 12, 2016, and U.S. Provisional Application No. 62 / 431,454, entitled "System for Treating a Substrate", filed on December 8, 2016, both of which are incorporated herein by reference in their entirety. Technical Field

[0004] The present invention relates to compositions, systems, and methods for treating substrates. The present invention also relates to substrates obtainable by treating with the systems and methods. Background Art

[0005] Oxidation and degradation of metals used in aerospace, commercial, and private industries are a serious and costly problem. To prevent oxidation and degradation of metals used in these applications, inorganic protective coatings can be applied to the metal surface. Such inorganic protective coatings, also referred to as conversion coatings, can be the only coating applied to the metal, or the coating can be an intermediate coating onto which a topcoat is subsequently applied.

[0006] However, at least some of the coatings prepared using these compositions and methods form corrosion and / or pits on the surface. In addition, at least some of the conversion compositions known in the art may also suffer from one or more of the following disadvantages: (1) the tendency of the components to precipitate in solution and leave the metal surface in the form of a slurry material; (2) difficulty in obtaining a uniform coating that has no tendency to over - coat and exhibits poor adhesion to the substrate; (3) the necessity to use multiple steps and long time periods to deposit the coating; and (4) the necessity to use special pretreatment and solution compositions to coat multi - layer alloys, particularly aluminum 2024 alloy.

[0007] Therefore, there is a need for such conversion compositions and / or treatment systems that overcome several of the deficiencies, drawbacks, and undesirable parameters of known conversion coatings. Summary of the Invention

[0008] Disclosed herein is a system for treating a metal substrate, comprising: a conversion composition comprising an aqueous carrier and trivalent chromium cations in an amount of from 0.001 g / L to 20 g / L; and a sealing composition comprising lithium cations.

[0009] The present invention also discloses a method for treating a metal substrate, comprising: contacting at least a portion of the surface of the substrate with a conversion composition comprising trivalent chromium cations in an amount of 0.001 g / L to 20 g / L; and contacting at least a portion of the surface of the substrate with a sealing composition comprising lithium cations.

[0010] Also disclosed are substrates obtainable by treating with this system and / or obtainable by the treatment method. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A schematic view is shown which shows the layer thickness of the sealing composition on the surface of the substrate. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention relates to a system for treating a metal substrate, which system comprises or in certain cases consists essentially of, or in certain cases consists of: a conversion composition which comprises or in certain cases consists essentially of, or in certain cases consists of: an aqueous carrier and trivalent chromium cations in an amount of 0.001 g / L to 20 g / L; and a sealing composition which comprises or in certain cases, consists essentially of, or in certain cases, consists of: lithium cations. The present invention also relates to a method for treating a metal substrate, which method comprises or in certain cases consists essentially of, or in certain cases consists of: contacting at least a portion of the surface of the substrate with a conversion composition which comprises, or in certain cases, consists essentially of, or in certain cases, consists of: trivalent chromium cations in an amount of 0.001 g / L to 20 g / L; and contacting at least a portion of the surface of the substrate with a sealing composition which comprises lithium cations, or in certain cases consists essentially of lithium cations, or in certain cases consists of lithium cations.

[0013] Suitable substrates for use in the present invention include metallic substrates, metal alloy substrates, and / or metallized substrates such as nickel-plated plastics. According to the present invention, the metal or metal alloy may comprise or be steel, aluminum, zinc, nickel, and / or magnesium. For example, the steel substrate may be cold-rolled steel, hot-rolled steel, electro-galvanized steel, and / or hot-dip electro-galvanized steel. 1XXX, 2XXX, 3XXX, 4XXX, 5XXX, 6XXX, or 7XXX series aluminum alloys and clad aluminum alloys may also be used as substrates. The aluminum alloy may contain from 0.01 wt% to 10 wt% copper. The treated aluminum alloy may further include castings such as 1XX.X, 2XX.X, 3XX.X, 4XX.X, 5XX.X, 6XX.X, 7XX.X, 8XX.X, or 9XX.X (e.g., A356.0). AZ31B, AZ91C, AM60B, or EV31A series magnesium alloys may also be used as substrates. The substrates used in the present invention may further comprise titanium and / or titanium alloys, zinc and / or zinc alloys, and / or nickel and / or nickel alloys. According to the present invention, the substrate may comprise a part of a vehicle such as a vehicle body (e.g., but not limited to doors, body panels, trunk lids, roof panels, hoods, roofs, and / or side rails, rivets, landing components, and / or skins (for use on aircraft)) and / or a vehicle frame. As used herein, "vehicle" or variations thereof include, but are not limited to, civilian, commercial, and military aircraft, and / or land vehicles such as cars, motorcycles, and / or trucks.

[0014] As described above, the conversion composition of the present invention may comprise a conversion composition containing trivalent chromium cations. The conversion composition may further comprise anions (which may be adapted to form salts with the trivalent chromium cations), including, for example, sulfate, nitrate, acetate, carbonate, hydroxide, or combinations thereof.

[0015] According to the present invention, the amount of the trivalent chromium salt present in the conversion composition may be at least 0.001 g / L, such as at least 0.1 g / L, such as at least 0.5 g / L, and in some cases, not exceeding 20 g / L, such as not exceeding 10 g / L, such as not exceeding 5 g / L. According to the present invention, the amount of the trivalent chromium salt present in the conversion composition may be from 0.001 g / L to 20 g / L, such as from 0.1 g / L to 10 g / L, such as from 0.5 g / L to 5 g / L.

[0016] Optionally, according to the present invention, the conversion composition may further comprise metal cations, such as Group I and / or Group II metal cation salts. In such cases, the anions forming salts with the Group I and / or Group II cations may include, for example, halide ions, nitrate, sulfate, acetate, phosphate, silicate (orthosilicate and metasilicate), carbonate, hydroxide, etc.

[0017] Optionally, according to the present invention, the conversion composition may further comprise at least one coinhibitor. In an example, the coinhibitor may comprise Group IIA metal cations, transition metal cations, lanthanide cations, azoles or combinations thereof. According to the present invention, the lanthanide cations may include, for example, cerium, praseodymium, terbium or combinations thereof; the Group IIA metal cations may comprise magnesium; the transition metal cations may include Group IIIB metals such as yttrium, scandium or combinations thereof, Group IVB metal cations such as zirconium, titanium, hafnium or combinations thereof, Group VB metal cations such as vanadium, Group VIB metal cations such as molybdenum, Group VIIB metal cations such as manganese; and / or Group XII metal cations such as zinc.

[0018] According to the present invention, the conversion composition may further comprise anions that may be suitable for forming salts with the metal cations of the coinhibitor(s) of the conversion composition, such as halide ions, nitrate, sulfate, phosphate, silicate (orthosilicate and metasilicate), carbonate, acetate, hydroxide, etc.

[0019] According to the present invention, the salts of the coinhibitor of the conversion composition may be present in the conversion composition in an amount of at least 0.001 g / L, for example at least 0.1 g / L, for example at least 0.5 g / L, and in some cases, not exceeding 20 g / L, for example not exceeding 10 g / L, for example not exceeding 5 g / L. According to the present invention, the salts of the coinhibitor of the conversion composition may be present in the conversion composition in an amount of 0.001 g / L to 20 g / L, for example 0.1 g / L to 10 g / L, for example 0.5 g / L to 5 g / L.

[0020] According to the present invention, the conversion composition may exclude hexavalent chromium or compounds containing hexavalent chromium. Non-limiting examples of such materials include chromic acid, chromium trioxide, chromium anhydride, dichromates such as ammonium dichromate, sodium dichromate, potassium dichromate and calcium dichromate, barium dichromate, magnesium dichromate, zinc dichromate, cadmium dichromate and strontium dichromate. When the conversion composition and / or the coating or layer formed therefrom, respectively, is substantially free, essentially free or completely free of hexavalent chromium, this includes any form of hexavalent chromium, such as but not limited to the hexavalent chromium-containing compounds listed above.

[0021] Thus, optionally, according to the present invention, the conversion composition and / or the coating or layer deposited therefrom may be substantially free, essentially free and / or completely free of one or more of any of the elements or compounds listed in the preceding paragraph. A conversion composition substantially free of hexavalent chromium or its derivatives and / or a coating or layer formed therefrom respectively means that hexavalent chromium or its derivatives are not intentionally added but may be present in trace amounts, for example due to impurities from the environment or inevitable contamination. In other words, the amount of the material is so small that it does not affect the performance of the conversion composition; in the case of hexavalent chromium, this may further include that the element or its compound is not present in such a level in the conversion composition and / or the coating or layer formed therefrom that causes an environmental burden. The term "substantially free" means that the conversion composition and / or the coating or layer formed therefrom contains less than 10 ppm of any or all of the elements or compounds listed in the preceding paragraph, respectively based on the total weight of the composition or layer, if present. The term "essentially free" means that the conversion composition and / or the coating or layer formed therefrom contains less than 1 ppm of any or all of the elements or compounds listed in the preceding paragraph, if present. The term "completely free" means that the conversion composition and / or the coating or layer formed therefrom contains less than 1 ppb of any or all of the elements or compounds listed in the preceding paragraph, if present.

[0022] According to the present invention, the conversion composition may exclude phosphate ions or phosphate-containing compounds and / or form slurries, such as aluminum phosphate, iron phosphate and / or zinc phosphate, in some cases, which are formed in the case of using a zinc phosphate-based treatment agent. As used herein, "phosphate-containing compounds" include compounds containing the element phosphorus such as orthophosphates, pyrophosphates, metaphosphates, tripolyphosphates, organic phosphonates, etc., and may include but are not limited to monovalent, divalent or trivalent cations such as: sodium, potassium, calcium, zinc, nickel, manganese, aluminum and / or iron. When the conversion composition and / or the layer or coating containing it is substantially free, essentially free or completely free of phosphates, this includes any form of phosphate ions or phosphate-containing compounds.

[0023] Thus, according to the present invention, the conversion composition and / or the layer deposited therefrom can be substantially free of, or in some cases essentially free of, or in some cases completely free of one or more of any of the ions or compounds listed in the foregoing paragraph. A conversion composition and / or a layer deposited therefrom that is substantially free of phosphates means that phosphate ions or phosphate-containing compounds are not intentionally added, but may be present in trace amounts, for example due to impurities from the environment or inevitable contamination. In other words, the amount of such material is so small that it does not affect the performance of the composition; this may further include that phosphates do not exist in such levels in the conversion composition and / or the layer deposited therefrom that they cause an environmental burden. The term "substantially free of" means that the conversion composition and / or the layer deposited therefrom contains less than 5 ppm of any or all of the phosphate anions or compounds listed in the foregoing paragraph, based on the total weight of the composition or layer, if present. The term "essentially free of" means that the conversion composition and / or the layer containing it contains less than 1 ppm of any or all of the phosphate anions or compounds listed in the foregoing paragraph. The term "completely free of" means that the conversion composition and / or the layer containing it contains less than 1 ppb of any or all of the phosphate anions or compounds listed in the foregoing paragraph, if present.

[0024] According to the present invention, in some cases, the pH of the conversion composition can be less than 7, such as less than 5, such as from 1.5 to 6.9, such as from 2.0 to 6.0, such as from 2.5 to 4.5. In other cases, the pH of the conversion composition can be greater than 7, such as greater than 9, such as greater than 11, such as from 7.1 to 13, such as from 7.5 to 11, such as from 8 to 10. Whether the conversion composition is acidic or basic, the pH can be adjusted as needed using, for example, any acid and / or base. Thus, according to the present invention, the pH of the conversion composition can be maintained by including an acidic substance, which includes water-soluble and / or water-dispersible acids, such as nitric acid, sulfuric acid, and / or phosphoric acid. Additionally, according to the present invention, the pH of the composition can be maintained by including a basic substance, which includes water-soluble and / or water-dispersible bases, such as sodium hydroxide, sodium carbonate, potassium carbonate, potassium hydroxide, ammonium hydroxide, ammonia, and / or amines, such as triethylamine, methyl ethylamine, or mixtures thereof.

[0025] The conversion composition may comprise an aqueous medium and may optionally comprise other materials such as nonionic surfactants and adjuvants commonly used in the field of conversion compositions. Water-dispersible organic solvents may be present in the aqueous medium, such as alcohols having up to about 8 carbon atoms such as methanol, isopropyl alcohol, etc.; or glycol ethers such as monoalkyl ethers of ethylene glycol, diethylene glycol or propylene glycol, etc. When present, the typical amount of the water-dispersible organic solvent is at most about 10% by volume, based on the total volume of the aqueous medium. Additionally, in the aqueous medium, thickeners may be present, such as cellulose, silicated or acrylic thickeners. When present, such thickeners are typically used in an amount of at least 0.00001% by weight, such as at least 0.5% by weight, and in some cases, not more than 5% by weight, such as not more than 1% by weight. When present, such thickeners are typically used in an amount of from 0.00001% by weight to 5% by weight, such as from 0.5% by weight to 1% by weight.

[0026] Other optional materials include surfactants, which act as defoamers or substrate wetting agents. Anionic, cationic, amphoteric and / or nonionic surfactants may be used. The defoaming surfactant may optionally be present at a level of up to 1% by weight, such as up to 0.1% by weight, and the wetting agent is typically present at a level of up to 2%, such as up to 0.5% by weight, based on the total weight of the conversion composition.

[0027] As described above, the conversion composition may comprise a carrier, often an aqueous medium, such that the composition is in the form of a solution or dispersion of trivalent chromium cations and optionally other metal ions and / or co-inhibitors in the carrier. According to the present invention, the solution or dispersion may be contacted with the substrate by any of a variety of known techniques, such as dipping or immersion, spraying, intermittent spraying, dipping followed by spraying, spraying followed by dipping, brushing or roll coating. According to the present invention, the solution or dispersion may be at a temperature of 40°F - 160°F, such as 60°F - 110°F, such as 70°F - 90°F when applied to a metal substrate. For example, the conversion process may be carried out at ambient temperature or room temperature. The contact time is often from 1 second to 30 minutes, such as from 30 seconds to 15 minutes, such as from 4 minutes to 10 minutes.

[0028] According to the present invention, after contact with the conversion composition, the substrate can optionally be air dried at room temperature or can be dried with hot air, for example using an air knife to flash off water by briefly exposing the substrate to high temperature, for example drying the substrate in an oven at 15°C - 100°C, such as 20°C - 90°C, or using infrared heating in a heater assembly, for example for 10 minutes at 70°C, or passing the substrate between doctor rolls. According to the present invention, after contact with the conversion composition, the substrate can optionally be rinsed with an aqueous solution of tap water, deionized water, reverse osmosis (RO) water, and / or a rinsing agent to remove any residues, and then optionally can be dried, for example air dried or hot air dried, as described in the previous sentence.

[0029] According to the present invention, before at least a portion of the substrate surface comes into contact with the above-mentioned conversion composition, at least a portion of the substrate surface can be cleaned and / or deoxygenated to remove grease, dirt, and / or other foreign substances. At least a portion of the substrate surface can be cleaned by physical and / or chemical means, such as mechanically abrading the surface and / or cleaning / degreasing the surface with an alkaline or acidic cleaning composition. Such cleaners are often before or after a water rinse, for example with tap water, distilled water, RO water, or a combination thereof. As used herein, a "cleaning composition" included in the treatment systems and methods of the present invention can also have a deoxygenating function in addition to its degreasing properties.

[0030] As described above, according to the present invention, the cleaning composition can be alkaline and can have a pH greater than 7, for example greater than 9, such as greater than 11. According to the present invention, the pH of the cleaning composition can be from 7 to 13, for example from 9 to 12.7. In other cases, according to the present invention, the cleaning composition can be acidic and can have a pH less than 7, for example less than 6, such as less than 5.5. According to the present invention, the pH of the cleaning composition can be from 0.5 to 6, for example from 1.5 to 4.5.

[0031] In an example of the present invention, the cleaning composition can include commercially available alkaline cleaners, including Chemkleen TM163,177,611L, 490MX, 2010LP, and 181ALP, Ultrax 32, Ultrax 97, and Ultrax 94D, each of which is commercially available from PPG Industries, Inc. (Cleveland, OH), and any DFM series, RECC 1001, and 88X1002 cleaners, commercially available from PRC-DeSoto International, Sylmar, CA), and Turco 4215-NCLT and Ridolene (commercially available from Henkel Technologies, Madison Heights, MI) and any SOCOCLEAN series cleaners (commercially available from Socomore).

[0032] According to the present invention, the cleaning composition may comprise hydroxide and / or phosphate and / or metasilicate. According to the present invention, hydroxide ions (if present) may be present in the composition in an amount of 0.05 to 25 g / 1000 g of solution, for example 18 to 20 g / 1000 g of solution. In a composition having phosphate, the phosphate may include phosphate (PO 4 ) 3- , dihydrogen phosphate (H 2 PO 4 ) - and / or pyrophosphate (P 2 O 7 ) 4- , for example phosphate (PO 4 ) 3- and / or pyrophosphate (P 2 O 7 ) 4- . The phosphate may be present in the composition in an amount of 50 g / 1000 g of solution to 10 g / 1000 g of solution, for example 70 g / 1000 g of solution to 90 g / 1000 g of solution. Other non-limiting examples of suitable phosphates include organic phosphates, such as those available from Monsanto (St. Louis, Mo.)

[0033] According to the present invention, the cleaning composition may comprise hydrogen and / or minerals, such as iron, potassium, etc. For example, the cleaning composition may comprise phosphoric acid, acetic acid, nitric acid, sulfuric acid, hydrofluoric acid, hydrochloric acid, and / or iron sulfate.

[0034] In an example, the cleaning composition of the present invention may optionally further comprise a corrosion inhibitor, which comprises a metal cation and / or an azole compound. According to the present invention, the metal cation in the corrosion inhibitor (when included) may comprise various metal cations having corrosion inhibition properties. For example, the metal cation may include lanthanide elements, Group IA metals, Group IIA metals, and / or transition metals.

[0035] According to the present invention, the cleaning composition may comprise a corrosion inhibitor, which comprises a metal cation at a concentration of at least 0.01 g / L, for example at least 0.05 g / L, for example at least 0.1 g / L, for example at least 1 g / L, and in some cases, the concentration present in the cleaning composition may not be greater than 25 g / L, for example not greater than 16 g / L, for example not greater than 10 g / L, for example not greater than 5 g / L. According to the present invention, the metal cation may be present in the cleaning composition at a concentration of 0.01 g / L to 25 g / L of the composition, for example 0.05 g / L to 16 g / L, for example 0.1 g / L to 10 g / L, for example 1 g / L to 5 g / L. In some cases, the upper limit of the amount of the metal ion may depend on the solubility of the salt used as the source of the metal ion. As discussed in further detail below, the metal cation may be provided in the composition in the form of a metal salt, in which case the amounts listed herein reflect the amount of the salt in the composition.

[0036] As described above, the metal cation may be provided in the cleaning composition in the form of a salt (i.e., the metal salt may serve as the source of the metal cation in the composition), and the salt has an anion and a metal cation as the cation of the salt. The anion of the salt may be any suitable anion capable of forming a salt with lanthanide elements, Group IA metals, Group IIA metals, and / or transition metals. Non-limiting examples of such anions include carbonate, hydroxide, nitrate, halide ion, sulfate, phosphate, and / or silicate (e.g., orthosilicate and metasilicate). However, the cleaning composition according to the present invention may comprise at least one hydroxide and / or phosphate. Optionally, according to the present invention, the cleaning composition may comprise at least two metal salts, and the at least two metal salts may comprise different anions and / or cations from each other. For example, the at least two metal salts may comprise different anions but the same cation, or may comprise different cations but the same anion.

[0037] As described above, the cleaning composition of the present invention may contain a halogen. The halogen may be provided in the composition in the form of a salt with the above-mentioned metal cations. According to the present invention, the halogen may be present in the cleaning composition in an amount of at least 0.2 g / L of the cleaning composition (and when the halogen is provided in the form of a salt, the salt may be present in the composition), and in some cases, may be present in an amount not exceeding 1.5 g / L of the cleaning composition. According to the present invention, the halogen may be present in the cleaning composition in an amount of from 0.2 g / L of the cleaning composition to 1.5 g / L of the cleaning composition.

[0038] Optionally, the cleaning composition of the present invention may further contain a nitrogen-containing heterocyclic compound. The nitrogen-containing heterocyclic compound may include cyclic compounds having 1 nitrogen atom such as pyrrole, and azole compounds having 2 or more nitrogen atoms such as pyrazole, imidazole, triazole, tetrazole and pentazole, 1 nitrogen atom and 1 oxygen atom, such as oxazole and isoxazole, or 1 nitrogen atom and 1 sulfur atom, such as thiazole and isothiazole. Non-limiting examples of suitable azole compounds include 2,5-dimercapto-1,3,4-thiadiazole (CAS: 1072-71-5), 1H-benzotriazole (CAS: 95-14-7), 1H-1,2,3-triazole (CAS: 288-36-8), 2-amino-5-mercapto-1,3,4-thiadiazole (CAS: 2349-67-9), also known as 5-amino-1,3,4-thiadiazole-2-thiol, and 2-amino-1,3,4-thiadiazole (CAS: 4005-51-0). In some embodiments, for example, the azole compound comprises 2,5-dimercapto-1,3,4-thiadiazole. Further, according to the present invention, the nitrogen-containing heterocyclic compound may be in the form of a salt such as a sodium salt.

[0039] According to the present invention, the nitrogen-containing heterocyclic compound may be present in the cleaning composition in an amount of at least 0.5 g / L of the cleaning composition, such as at least 1 g / L of the cleaning composition, such as at least 5 g / L of the composition, and in some cases may be present in an amount not exceeding 15 g / L of the composition, such as not exceeding 12 g / L of the composition, such as not exceeding 10 g / L of the composition. According to the present invention, the nitrogen-containing heterocyclic compound may be present in the cleaning composition in an effective corrosion-inhibiting amount, for example, from 0.5 g / L of the composition to 15 g / L of the composition, such as from 1 g / L of the composition to 12 g / L of the composition, such as from 5 g / L of the composition to 10 g / L of the composition.

[0040] According to the present invention, the cleaning composition may contain other components and / or additives, such as but not limited to carbonates, surfactants, chelating agents, thickeners, allantoin, polyvinylpyrrolidone, 2,5-dimercapto-1,3,4-thiadiazole, halides, adhesion promoters, such as adhesion promoting silanes (e.g., silanes having amine and / or hydroxyl functionality; or zirconium alkoxides and / or silane coupling agents) and alcohols. For example, according to the present invention, the surfactant (if present) may be present in the cleaning composition in an amount from 0.015 g / 1000 g solution to 60 g / 1000 g solution. Surfactants suitable for use in the present invention include Dynol 604 and Carbowet TM DC01 surfactant (both commercially available from Air Products, with an office in Allentown, Pennsylvania) and Triton X-100 (available from The Dow Chemical Company, Midland Mich).

[0041] Additionally, optionally, according to the present invention, the additive may comprise polyvinylpyrrolidone, which, if present, may be present in the cleaning composition in an amount from 0.01 g / L of the cleaning composition to 5 g / L of the cleaning composition, such as from 0.02 g / L of the cleaning composition to about 1 g / L of the cleaning composition.

[0042] According to the present invention, the cleaning composition of the present invention may comprise a carrier such as water, such that the cleaning composition is in the form of a solution or dispersion. According to the present invention, the solution or dispersion may be contacted with the substrate by any of a variety of techniques, including but not limited to dipping, spraying, swabbing, or spreading using a brush, roller, etc. With respect to application by spraying, conventional (automatic or manual) spraying techniques and equipment (for air spraying) may be used. According to the present invention, an electrolytic coating system may be used to apply the cleaning composition. The dwell time for which the cleaning composition remains in contact with the metal substrate may vary from a few seconds to several hours, such as less than 30 minutes or three minutes or less.

[0043] When the cleaning composition is applied to the metal substrate by immersion, the immersion time may vary from a few seconds to several hours, such as less than 30 minutes or three minutes or less, such as 2 seconds. When the cleaning composition is applied to the metal substrate using spraying, conventional spraying methods may be used to contact at least a portion of the composition with the substrate. The dwell time for which the cleaning composition remains in contact with the metal substrate may vary from a few seconds to several hours, such as less than 30 minutes or three minutes or less, such as 2 seconds.

[0044] After contacting the metal substrate with the cleaning composition, the metal substrate can optionally be air-dried and then rinsed with tap water, RO water, and / or distilled / deionized water. Alternatively, after contacting the metal substrate with the composition, the metal substrate can be rinsed with tap water, RO water, and / or distilled / deionized water and then air-dried (if desired). However, the substrate does not need to be dried, and in some cases, drying is omitted. Additionally, as described above, rinsing the substrate is not required, and then the metal substrate can be further coated with a conversion coating, primer, and / or topcoat to obtain a substrate with a final coating. Thus, in some cases, subsequent rinsing can be omitted.

[0045] In some cases, according to the present invention, the cleaning composition can be applied to the metal substrate for 1 to 10 minutes (e.g., 3 to 5 minutes), and the surface of the metal substrate can be kept wet by reapplying the composition. Then, after the last application of the composition, the composition is optionally dried, e.g., dried for 5 to 10 minutes (e.g., 7 minutes) in the absence of heat above room temperature. However, it is not necessary to dry the substrate, and in some cases, drying is omitted. For example, according to the present invention, a solvent (e.g., alcohol) can be used to rinse the substrate, which allows the drying step to be omitted.

[0046] After contacting the metal substrate with the cleaning composition, the metal substrate can optionally be air-dried. However, the substrate does not need to be dried, and in some cases, drying can be omitted. Rinsing is not required, but can be performed if desired.

[0047] According to the present invention, the metal substrate can optionally be conditioned before contacting the metal substrate with the above-described cleaning composition. As used herein, the term "conditioning" refers to surface modification of the substrate prior to subsequent processing. Such surface modification can include various operations, including but not limited to cleaning (removing impurities and / or dirt from the surface), deoxidizing, and / or applying a solution or coating, as known in the art. Conditioning can have one or more benefits, such as producing a more uniform starting metal surface, improving adhesion to subsequent coatings on the pretreated substrate, and / or modifying the starting surface in a manner that facilitates deposition of subsequent compositions.

[0048] According to the present invention, before applying the composition to the metal substrate, the metal substrate can be pretreated by solvent wiping the metal. Non-limiting examples of suitable solvents include methyl ethyl ketone (MEK), methyl propyl ketone (MPK), acetone, etc.

[0049] According to the present invention, the metal substrate may optionally be prepared by first subjecting the metal substrate to a solvent treatment prior to contacting the metal substrate with the cleaning composition. As used herein, the term "solvent treatment" refers to rinsing, wiping, spraying, or dipping the substrate in a solvent that aids in removing inks, oils, etc. that may be on the metal surface. Alternatively, the metal substrate may be prepared by degreasing the metal substrate using conventional degreasing methods prior to contacting the metal substrate with the cleaning composition.

[0050] Other optional methods of preparing the metal substrate include using a surface brightener, such as an acid wash or a light acid etch, or a soil remover.

[0051] The metal substrate may be rinsed with tap water, RO water, and / or distilled / deionized water between each pretreatment step and may be thoroughly rinsed with distilled / deionized water and / or alcohol after contact with the composition according to the present invention. However, as noted above, according to the present invention, some of the above pretreatment procedures and rinses may not be necessary before or after the application of the cleaning composition.

[0052] As described above, according to the present invention, at least a portion of the surface of the cleaned substrate can be deoxidized mechanically and / or chemically. As used herein, the term "deoxidation" means removing the oxide layer present on the substrate surface to facilitate the uniform deposition of the pretreatment composition (described below) and to promote the adhesion of the pretreatment composition coating to the substrate surface. Suitable deoxidizers will be well known to those skilled in the art. A typical mechanical deoxidizer can be, for example, using a scrubbing or cleaning pad to make the substrate surface uniformly roughened. Typical chemical deoxidizers include, for example, acid-based deoxidizers such as phosphoric acid, nitric acid, fluoboric acid, sulfuric acid, chromic acid, hydrofluoric acid, and ammonium bifluoride, or Amchem 7 / 17 deoxidizer (obtained from Henkel Technologies, Madison Heights, MI), OAKITE DEOXIDIZER LNC (commercially available from Chemetall), TURCO DEOXIDIZER 6 (commercially available from Henkel), or combinations thereof. Generally, the chemical deoxidizer comprises a carrier, often an aqueous medium, such that the deoxidizer can be in the form of a solution or dispersion in the carrier, in which case the solution or dispersion can be contacted with the substrate by any of a variety of known techniques, such as dipping or immersion, spraying, intermittent spraying, dipping followed by spraying, spraying followed by dipping, brushing, or roll coating. According to the present invention, when applied to a metal substrate, those skilled in the art will select the temperature range of the solution or dispersion based on the etching rate, for example, at a temperature of 50°F - 150°F (10°C - 66°C), such as 70°F - 130°F (21°C - 54°C), such as 80°F - 120°F (27°C - 49°C). The contact time can be 30 seconds - 20 minutes, such as 1 minute - 15 minutes, such as 90 seconds - 12 minutes, such as 3 minutes - 9 minutes.

[0053] The sealing composition can comprise lithium cations. The lithium cations can be in the form of a lithium salt. Additionally, the sealing composition can further comprise at least one non-lithium Group IA metal cation, Group VB metal cation, and / or Group VIB metal cation. The at least one non-lithium Group IA metal cation, Group VB metal cation, and / or Group VIB metal cation can be in the form of a salt. Non-limiting examples of anions suitable for forming salts with lithium, non-lithium Group IA cations, Group VB cations, and / or Group VIB cations include carbonate, hydroxide, nitrate, halide, sulfate, phosphate, and silicate (e.g., orthosilicate and metasilicate), such that the metal salt can comprise carbonate, hydroxide, nitrate, halide, sulfate, phosphate, silicate (e.g., orthosilicate or metasilicate), permanganate, chromate, vanadate, molybdate, and / or perchlorate.

[0054] According to the present invention, the metal salts of the sealing composition (i.e., salts of lithium, non-lithium Group IA metals, Group VB and / or Group VIB) can each be present in the sealing composition in an amount of at least 25 ppm, such as at least 150 ppm, such as at least 500 ppm (calculated as the total compound), based on the total weight of the sealing composition, and in some cases not greater than 30,000 ppm, such as not greater than 2,000 ppm, such as not greater than 1,500 ppm (calculated as the total compound), based on the total weight of the sealing composition. According to the present invention, the metal salts of the sealing composition (i.e., salts of lithium, non-lithium Group IA metals, Group VB and / or Group VIB) can each be present in the sealing composition in an amount of 25 ppm - 30,000 ppm, such as 150 ppm - 2,000 ppm, such as 500 ppm - 1,500 (calculated as the total compound), based on the total weight of the sealing composition.

[0055] According to the present invention, the lithium cations, non-lithium Group IA cations, Group VB metal cations and Group VIB metal cations can each be present in the sealing composition in an amount of at least 5 ppm, such as at least 50 ppm, such as at least 150 ppm, such as at least 250 ppm (calculated as cations), based on the total weight of the sealing composition, and in some cases the amount can be not greater than 5,500 ppm, such as not greater than 1,200 ppm, such as not greater than 1,000 ppm, such as not greater than 500 ppm (calculated as cations), based on the total weight of the sealing composition. In some cases, according to the present invention, the lithium cations, non-lithium Group IA cations, Group VB metal cations and Group VIB metal cations can each be present in the sealing composition in an amount of 5 ppm - 5,500 ppm, such as 50 ppm - 1,000 ppm (calculated as cations), based on the total weight of the sealing composition, such as 150 ppm - 500 ppm.

[0056] According to the present invention, the lithium salts of the present invention can include inorganic lithium salts, organic lithium salts or combinations thereof. According to the present invention, both the anions and cations of the lithium salts can be soluble in water. According to the present invention, for example, the solubility constant of the lithium salt in water at a temperature of 25 °C (K; 25 °C) can be at least 1 x 10 -11 , such as at least 1 x 10 -4 and in some cases can be not greater than 5 x 10 +2 . According to the present invention, the solubility constant of the lithium salt in water at a temperature of 25 °C (K; 25 °C) can be 1 x 10 -11 to 5 x 10 +2 , such as 1 x 10 -4 - 5 x 10 +2As used herein, "solubility constant" refers to the product of the equilibrium concentrations of the ions in a saturated aqueous solution of the respective lithium salt. Each concentration is raised to the power of its respective ionic coefficient in the equilibrium equation. Solubility constants for different salts can be found in the Handbook of Chemistry and Physics.

[0057] According to the present invention, the sealing composition of the present invention may include an oxidizing agent, such as hydrogen peroxide, persulfate, perchlorate, jet oxygen, bromate, benzoyl peroxide, ozone, etc. or a combination thereof. For example, the sealing composition may contain 0.1 wt% - 15 wt% of the oxidizing agent, based on the total weight of the sealing composition, such as 2 wt% - 10 wt%, such as 6 wt% - 8 wt%. Alternatively, according to the present invention, the sealing composition may be substantially free of, or in some cases essentially free of, or in some cases completely free of, an oxidizing agent.

[0058] According to the present invention, the sealing composition may exclude compounds containing Group IIA metal cations or Group IIA metals, including but not limited to calcium. Non-limiting examples of such materials include Group IIA metal hydroxides, Group IIA metal nitrates, Group IIA metal halides, Group IIA metal amidosulfonates, Group IIA metal sulfates, Group IIA carbonates, and / or Group IIA metal carboxylates. When the sealing composition and / or the coating or layer formed therefrom is substantially free of, essentially free of, or completely free of Group IIA metal cations, this includes any form of Group IIA metal cation, such as but not limited to the Group IIA metal-containing compounds listed above.

[0059] According to the present invention, the sealing composition may exclude chromium or chromium-containing compounds. As used herein, the term "chromium-containing compound" refers to materials including hexavalent chromium. Non-limiting examples of such materials include chromic acid, chromium trioxide, chromium anhydride, dichromates such as ammonium dichromate, sodium dichromate, potassium dichromate, and calcium dichromate, barium dichromate, magnesium dichromate, zinc dichromate, cadmium dichromate, and strontium dichromate. When the sealing composition and / or the coating or layer formed therefrom is substantially free of, essentially free of, or completely free of chromium, this includes any form of chromium, such as but not limited to the hexavalent chromium-containing compounds listed above.

[0060] Thus, optionally, according to the present invention, the sealing composition of the present invention and / or the coating or layer deposited therefrom may be substantially free, essentially free and / or completely free of one or more of any of the elements or compounds listed in the preceding paragraph. The sealing composition and / or the coating or layer formed therefrom (which is substantially free of chromium or its derivatives) means that chromium or its derivatives are not intentionally added but may be present in trace amounts, for example, due to impurities from the environment or inevitable contamination. In other words, the amount of the material is so small that it does not affect the performance of the sealing composition; in the case of chromium, this may further include that the element or its compound does not exist in the sealing composition and / or the coating or layer formed therefrom at such a level that it causes an environmental burden. The term "substantially free" means that the sealing composition and / or the coating or layer formed therefrom contains less than 10 ppm of any or all of the elements or compounds listed in the preceding paragraph, based on the total weight of the composition or layer, if present. The term "essentially free" means that the sealing composition and / or the coating or layer formed therefrom contains less than 1 ppm of any or all of the elements or compounds listed in the preceding paragraph, if present. The term "completely free" means that the sealing composition and / or the coating or layer formed therefrom contains less than 1 ppb of any or all of the elements or compounds listed in the preceding paragraph, if present.

[0061] According to the present invention, in some cases, the sealing composition may exclude phosphate ions or phosphate-containing compounds and / or form slurries, such as aluminum phosphate, iron phosphate and / or zinc phosphate, which are formed in the case of using a zinc phosphate-based treatment agent. As used herein, "phosphate-containing compounds" include compounds containing the element phosphorus such as orthophosphates, pyrophosphates, metaphosphates, tripolyphosphates, organophosphonates, etc., and may include, but are not limited to, monovalent, divalent or trivalent cations such as: sodium, potassium, calcium, zinc, nickel, manganese, aluminum and / or iron. When the composition and / or the layer or coating containing it is substantially free, essentially free or completely free of phosphates, this includes any form of phosphate ions or phosphate-containing compounds.

[0062] Thus, according to the present invention, the sealing composition and / or the layer deposited therefrom may be substantially free, or in some cases may be essentially free, or in some cases may be completely free of one or more of any of the ions or compounds listed in the preceding paragraph. A sealing composition and / or a layer deposited therefrom that is substantially free of phosphates means that phosphate ions or phosphate-containing compounds are not intentionally added, but may be present in trace amounts, for example due to impurities from the environment or unavoidable contamination. In other words, the amount of the material is so small that it does not affect the performance of the composition; this may further include that phosphates are not present in the sealing composition and / or the layer deposited therefrom at such levels that they cause an environmental burden. The term "substantially free" means that the sealing composition and / or the layer deposited therefrom contains less than 5 ppm of any or all of the phosphate anions or compounds listed in the preceding paragraph, based on the total weight of the composition or layer, if present. The term "essentially free" means that the sealing composition and / or the layer containing it contains less than 1 ppm of any or all of the phosphate anions or compounds listed in the preceding paragraph. The term "completely free" means that the sealing composition and / or the layer containing it contains less than 1 ppb of any or all of the phosphate anions or compounds listed in the preceding paragraph, if present.

[0063] According to the present invention, the sealing composition may, in some cases, exclude fluoride or a fluoride source. As used herein, "fluoride source" includes monofluorides, difluorides, fluoride complexes, and mixtures thereof known to produce fluoride ions. When the composition and / or the layer or coating containing it is substantially free, essentially free, or completely free of fluoride, this includes any form of fluoride ions or fluoride source, but does not include inadvertent fluoride that may be present in the bath as a result of, for example, carryover from a prior treatment bath in a processing line, a municipal water source (e.g., addition of fluoride to the water supply to prevent tooth decay), fluoride from a pretreated substrate, etc. That is, a bath that is substantially free, essentially free, or completely free of fluoride may have inadvertent fluoride that may be derived from these external sources, even if the composition used to make the bath is substantially free, essentially free, or completely free of fluoride prior to being used in the processing line.

[0064] For example, the sealing composition may be substantially free of any fluoride source, such as ammonium and alkali metal fluorides, acid fluorides, fluoboric acid, fluorosilicic acid, fluotitanic acid, and fluozirconic acid and their ammonium and alkali metal salts, and other inorganic fluorides, non-exhaustive examples of which are: zinc fluoride, zinc aluminum fluoride, titanium fluoride, zirconium fluoride, nickel fluoride, ammonium fluoride, sodium fluoride, potassium fluoride, and hydrofluoric acid, and other similar materials known to those skilled in the art.

[0065] The fluoride present in the sealant composition that is not bonded to a metal ion such as a Group IVB metal ion, or a hydrogen ion, herein defined as "free fluoride") can be measured using, for example, an Orion Dual Star Dual Channel Benchtop Meter as an operating parameter in the sealant composition bath, the Orion Dual Star Dual Channel Benchtop Meter being equipped with a fluoride ion selective electrode ("ISE") obtained from Thermoscientific, a fluoride ion selective combination electrode provided by VWR International, or a similar electrode. See, for example, Light and Cappuccino, Determination of fluoride in toothpaste using an ion - selective electrode, J. Chem. Educ., 52:4, 247 - 250, April 1975. The fluoride ISE can be standardized by dipping the electrode into solutions of known fluoride concentration and recording the millivolt readings, then plotting these millivolt readings on a logarithmic graph. The millivolt readings of unknown samples can then be compared to this calibration graph and the fluoride concentration determined. Alternatively, the fluoride ISE can be used with an instrument that will perform internal calibration calculations and thus, after calibration, the concentration of unknown samples can be read directly. The fluoride ion is a small anion with a high charge density and thus in aqueous solution it often complexes with metal ions having a high positive charge density such as Group IVB metal ions, or with hydrogen ions. The fluoride anion in solution that is ionically or covalently bonded to a metal cation or hydrogen ion is herein defined as "bonded fluoride". Thus complexed fluoride ions are not measurable with a fluoride ISE unless the solution in which they are present is mixed with an ionic strength adjustment buffer (e.g.: citrate anion or EDTA) that releases fluoride ions from such complexes. At that point, (total) fluoride ions are measurable by the fluoride ISE and the measurement is referred to as "total fluoride". Alternatively, total fluoride can be calculated by comparing the weight of fluoride provided in the sealant composition to the total weight of the composition.

[0066]

[0067] ​According to the present invention, the treatment composition may be substantially free, or essentially free, or completely free of cobalt ions or cobalt-containing compounds in some cases. As used herein, "cobalt-containing compounds" include compounds, complexes or salts containing the element cobalt such as cobalt sulfate, cobalt nitrate, cobalt carbonate and cobalt acetate. When the composition and / or a layer or coating containing it is substantially free, essentially free or completely free of cobalt, this includes any form of cobalt ions or cobalt-containing compounds.

[0068] According to the present invention, the treatment composition may be substantially free, or essentially free, or completely free of vanadium ions or vanadium-containing compounds in some cases. As used herein, "vanadium-containing compounds" include compounds, complexes or salts containing the element vanadium such as vanadates and decavanadates, which include counterions of alkali metal or ammonium cations, including for example ammonium sodium decavanadate. When the composition and / or a layer or coating containing it is substantially free, essentially free or completely free of vanadium, this includes any form of vanadium ions or vanadium-containing compounds.

[0069] According to the present invention, the sealing composition may optionally further comprise an indicator compound, so named because it indicates the presence of, for example, chemical substances such as metal ions, the pH of the composition, etc. As used herein, "indicator", "indicator compound" and similar terms refer to compounds that change color in response to some external stimulus, parameter or condition, such as the presence of metal ions, or in response to a specific pH or pH range.

[0070] The indicator compound used according to the present invention may be any indicator known in the art that indicates the presence of substances, particularly pH, etc. For example, a suitable indicator may be one that changes color after forming a metal ion complex with a specific metal ion. The metal ion indicator is typically a highly conjugated organic compound. As used herein and as will be understood by those skilled in the art, "conjugated compound" refers to a compound that has two double bonds separated by a single bond, such as two carbon-carbon double bonds and a single carbon-carbon bond between them. Any conjugated compound may be used according to the present invention.

[0071] Similarly, the indicator compound can be such that it changes color upon a change in pH; for example, the compound can be one color at acidic or neutral pH and change color at basic pH, and vice versa. Such indicators are well known and widely used commercially. An indicator that "changes color upon transitioning from a first pH to a second pH" (i.e., from the first pH to a second pH that is more or less acidic or basic) thus has a first color (or is colorless) when exposed to the first pH and changes to a second color (or from colorless to colored) upon transitioning to the second pH (i.e., a pH that is more or less acidic or basic than the first pH). For example, an indicator that "changes color upon transitioning to a more basic pH (or less acidic pH)" changes from a first color / colorless to a second color / colored when the pH changes from acidic / neutral to basic. For example, an indicator that "changes color upon becoming a more acidic pH (or less basic pH)" changes from a first color / colorless to a second color / colored when the pH changes from basic / neutral to acidic.

[0072] Non-limiting examples of such indicator compounds include methyl orange, xylenol orange, catechol violet, bromophenol blue, green and violet, eriochrome black T, celestine blue, hematoxylin, calmagite, cyanine, and combinations thereof. Optionally, the indicator compound can comprise an organic indicator compound that is a metal ion indicator. Non-limiting examples of indicator compounds include those present in Table 1. Fluorescent indicators (which will emit light under certain conditions) can also be used according to the present invention, although the use of fluorescent indicators can also be explicitly excluded. That is, alternatively, conjugated compounds that exhibit fluorescence are explicitly excluded. As used herein, "fluorescent indicator" and like terms refer to such compounds, molecules, pigments, and / or dyes that will fluoresce or otherwise exhibit color (upon exposure to ultraviolet or visible light). "Fluoresce" will be understood to mean emit light after absorbing shorter wavelength light or other electromagnetic radiation. Examples of such indicators (often referred to as "tags") include acridine, anthraquinone, coumarin, diphenylmethane, diphenylnaphthylmethane, quinoline, stilbene, triphenylmethane, anthracene, and / or molecules containing any of these moieties and / or any derivatives of any of these such as rhodamine, phenanthridine, oxazine, fluorone, cyanine, and / or acridine.

[0073] Table 1

[0074]

[0075] According to the present invention, the conjugate compound that can be used as an indicator can, for example, contain catechol violet, as shown in Table 1. Catechol violet (CV) is a sulfonphthalein dye, which is manufactured by condensing 2 mol of pyrocatechol and 1 mol of o-sulfobenzoic anhydride. It has been found that CV has indicator properties and when introduced into a composition having metal ions, it forms a complex, which enables it to be used as a complexiometric agent. As the composition containing CV chelates with metal ions (i.e., those having divalent or higher valency) from a metal substrate, a color change from blue to blue-violet is generally observed.

[0076] As shown in Table 1, xylenol orange can also be used in the composition according to the present invention. It has been found that xylenol orange has indicator properties for metal ions (i.e., those having divalent or higher valency) and when introduced into a composition having metal ions, it forms a complex, which enables it to be used as a complexiometric agent. As the composition containing xylenol orange chelates metal ions, the xylenol orange solution changes color from red to generally blue.

[0077] According to the present invention, the amount of the indicator compound present in the sealing composition can be at least 0.01 g / 1000 g of the sealing composition, for example, at least 0.05 g / 1000 g of the sealing composition, and in some cases not more than 3 g / 1000 g of the sealing composition, for example, not more than 0.3 g / 1000 g of the sealing composition. According to the present invention, the amount of the indicator compound present in the sealing composition can be from 0.01 g / 1000 g of the sealing composition to 3 g / 1000 g of the sealing composition, for example, from 0.05 g / 1000 g of the sealing composition to 0.3 g / 1000 g of the sealing composition.

[0078] According to the present invention, the indicator compound that changes color in response to certain external stimuli provides a benefit when used in a sealing composition in that it can, for example, act as a visual indication that the substrate has been treated with the composition. For example, a sealing composition containing an indicator that changes color when exposed to metal ions present in the substrate changes color when complexing with the metal ions in that substrate; this allows the user to know that the substrate has come into contact with the composition. Similar benefits can be achieved by depositing an alkaline or acidic layer on the substrate and contacting the substrate with the composition of the present invention, which changes color when exposed to an alkaline or acidic pH.

[0079] Optionally, the sealing composition of the present invention may further comprise a nitrogen-containing heterocyclic compound. The nitrogen-containing heterocyclic compound may include cyclic compounds having 1 nitrogen atom such as pyrrole, and azole compounds having 2 or more nitrogen atoms such as pyrazole, imidazole, triazole, tetrazole and pentazole, 1 nitrogen atom and 1 oxygen atom, such as oxazole and isoxazole, or 1 nitrogen atom and 1 sulfur atom, such as thiazole and isothiazole. Non-limiting examples of suitable azole compounds include 2,5-dimercapto-1,3,4-thiadiazole (CAS: 1072-71-5), 1H-benzotriazole (CAS: 95-14-7), 1H-1,2,3-triazole (CAS: 288-36-8), 2-amino-5-mercapto-1,3,4-thiadiazole (CAS: 2349-67-9), also known as 5-amino-1,3,4-thiadiazole-2-thiol, and 2-amino-1,3,4-thiadiazole (CAS: 4005-51-0). In some embodiments, for example, the azole compound comprises 2,5-dimercapto-1,3,4-thiadiazole. Additionally, according to the present invention, the nitrogen-containing heterocyclic compound may be in the form of a salt such as a sodium salt.

[0080] The concentration of the nitrogen-containing heterocyclic compound present in the sealing composition may be at least 0.0005 g / L of the composition, for example at least 0.0008 g / L of the composition, for example at least 0.002 g / L of the composition and in some cases the amount present in the sealing composition may not be greater than 3 g / L of the composition, for example not greater than 0.2 g / L of the composition, for example not greater than 0.1 g / L of the composition. According to the present invention, the concentration of the nitrogen-containing heterocyclic compound present in the sealing composition (if any) may be 0.0005 g / L of the composition - 3 g / L of the composition, for example 0.0008 g / L of the composition - 0.2 g / L of the composition, for example 0.002 g / L of the composition - 0.1 g / L of the composition.

[0081] According to the present invention, the sealing composition may comprise an aqueous medium and may optionally comprise other materials such as at least one organic solvent. Non-limiting examples of suitable such solvents include propylene glycol, ethylene glycol, glycerol, low molecular weight alcohols, etc. When present, if any, the amount of the organic solvent present in the sealing composition may be at least 1 g of solvent / L of the sealing composition, for example at least about 2 g of solvent / L of the sealing composition and in some cases the amount present may not be greater than 40 g of solvent / L of the sealing composition, for example not greater than 20 g of solvent / L of the sealing composition. According to the present invention, the amount of the organic solvent present in the sealing composition (if any) may be 1 g of solvent / L of the sealing composition - 40 g of solvent / L of the sealing composition, for example 2 g of solvent / L of the sealing composition - 20 g of solvent / L of the sealing composition.

[0082] According to the present invention, the pH of the sealing composition can be at least 9.5, such as at least 10, such as at least 11 and in some cases may not be higher than 12.5, such as not higher than 12, such as not higher than 11.5. According to the present invention, the pH of the sealing composition can be 9.5 - 12.5, such as 10 - 12, such as 11 - 11.5. The pH of the sealing composition can be adjusted as needed using, for example, any acid and / or base. According to the present invention, the pH of the sealing composition can be maintained by including an acidic material, which includes carbon dioxide, water-soluble and / or water-dispersible acids such as nitric acid, sulfuric acid, and / or phosphoric acid. According to the present invention, the pH of the sealing composition can be maintained by including a basic material, including water-soluble and / or water-dispersible bases, which includes carbonates such as Group I carbonates, Group II carbonates, hydroxides such as sodium hydroxide, potassium hydroxide, or ammonium hydroxide, ammonia, and / or amines such as triethylamine, methyl ethylamine, or mixtures thereof.

[0083] As described above, the sealing composition can contain a carrier, often an aqueous medium, such that the composition is in the form of a solution or dispersion of lithium cations in the carrier. According to the present invention, the solution or dispersion can be contacted with the substrate by any of a variety of known techniques, such as dipping or immersion, spraying, intermittent spraying, dipping followed by spraying, spraying followed by dipping, brushing, or roll coating. According to the present invention, the solution or dispersion can be at a temperature of 40°F - about 160°F, such as 60°F - 110°F when applied to a metal substrate. For example, the method of contacting the metal substrate with the sealing composition can be carried out at ambient temperature or room temperature. The contact time is often about 1 second - about 15 minutes, such as about 5 seconds - about 2 minutes.

[0084] According to the present invention, after contact with the sealing composition, the substrate can optionally be air dried at room temperature or can be dried with hot air, for example by using an air knife, by briefly exposing the substrate to high temperature to flash off water, such as drying the substrate in an oven at 15°C - 100°C, such as 20°C - 90°C, or using infrared heating in a heater assembly, such as at 70°C for 10 minutes, or passing the substrate between squeegee rolls. According to the present invention, before any subsequent contact of the substrate surface with any water, solution, composition, etc., the substrate surface can be partially or in some cases completely dry. As used herein with respect to the substrate surface, "completely dry" or "completely dried" means that there is no moisture visible to the human eye on the substrate surface.

[0085] Optionally, according to the present invention, after contacting the sealing composition, the substrate is optionally not rinsed or contacted with any aqueous solution (described below) before at least a portion of the substrate surface is contacted with a subsequent treatment composition to form a film, layer, and / or coating thereon.

[0086] Optionally, according to the present invention, after contacting the sealing composition, the substrate can optionally be contacted with tap water, deionized water, RO water, and / or any aqueous solution known to those skilled in the art of substrate treatment, wherein such water or aqueous solution can be at a temperature from room temperature (60°F) - 212°F. The substrate can then optionally be dried, such as air drying or drying with hot air, as described in the previous paragraph, so that before any subsequent contact of the substrate surface with any water, solution, composition, etc., the substrate surface can be partially or in some cases completely dry.

[0087] According to the present invention, the layer thickness formed by the treatment composition can be, for example, at most 550 nm, such as 5 nm - 550 nm, such as 10 nm - 400 nm, such as 25 nm - 250 nm. The layer thickness formed by the treatment composition can be measured using some analytical techniques, including but not limited to XPS (X-ray photoelectron spectroscopy) depth profiling or TEM (transmission electron microscopy). As used herein, "thickness" when referring to a layer formed by the treatment composition of the present invention refers to (a) the layer formed above the initial air / substrate interface, (b) the modified layer formed below the pretreatment / substrate interface, or (c) both (a) and (b), as Figure 1 shown. Although Figure 1 the modified layer (b) is shown as extending to the pretreatment / substrate interface, an interlayer can be present between the modified layer (b) and the pretreatment / substrate interface. Similarly, (c), the combination of (a) and (b), is not limited to a continuous layer and can include multiple layers, with interlayers therebetween, and the measurement of the thickness of layer (c) can exclude said interlayers.

[0088] According to the present invention, disclosed herein is a substrate that comprises, or in some cases consists essentially of, or in some cases consists of: a film formed from a conversion composition that comprises, or in some cases consists of, or in some cases consists essentially of trivalent chromium.

[0089] According to the present invention, disclosed herein is a substrate that comprises, or in some cases consists essentially of, or in some cases consists of: a film formed from a conversion composition that comprises, or in some cases consists of, or in some cases consists essentially of trivalent chromium; a layer having a thickness of 5 nm to 550 nm, such as 10 nm to 400 nm, such as 25 nm to 250 nm, formed from a sealing composition.

[0090] According to the present invention, disclosed herein is a method of treating a substrate, which comprises, or in some cases consists essentially of, or in some cases consists of: contacting at least a portion of the surface of the substrate with a conversion composition, the conversion composition comprising, or in some cases consisting of, or in some cases consisting essentially of trivalent chromium.

[0091] According to the present invention, disclosed herein is a method of treating a substrate, which comprises, or in some cases consists essentially of, or in some cases consists of: contacting at least a portion of the substrate with a conversion composition, the composition comprising, or in some cases consisting of, or in some cases consisting essentially of trivalent chromium; and contacting the surface that has been in contact with the conversion composition with a sealing composition.

[0092] It has surprisingly been found that the corrosion performance is improved when treating the substrate with a lithium-containing sealing composition (i.e., a composition without hydrogen peroxide) after conventional cleaning and deoxidation treatment and treatment with a trivalent chromium conversion composition, as compared to substrates treated with a sealing composition containing hydrogen peroxide. These results are unexpected.

[0093] According to the present invention, after the substrate has been in contact with the sealing composition, a coating composition comprising a film-forming resin can be deposited on at least a portion of the surface of the substrate that has been in contact with the sealing composition. Any suitable technique can be used to deposit such a coating composition on the substrate, including, for example, brushing, dipping, flow coating, spraying, etc. However, in some cases, as described in more detail below, such deposition of the coating composition can include an electrophoretic coating step, wherein an electrodepositable composition is deposited onto the metal substrate by electrodeposition. In certain other cases, as described in more detail below, such deposition of the coating composition comprises a powder coating step. In still other cases, the coating composition can be a liquid coating composition.

[0094] According to the present invention, the coating composition may comprise a thermosetting film-forming resin or a thermoplastic film-forming resin. As used herein, the term "film-forming resin" refers to a resin that can form a self-supporting continuous film on at least the horizontal surface of a substrate when any diluent or carrier present in the composition is removed or when cured at ambient temperature or elevated temperature. Conventional film-forming resins that can be used include, but are not limited to, those commonly used in automotive OEM coating compositions, automotive refinish coating compositions, industrial coating compositions, architectural coating compositions, coil coating compositions, and aerospace coating compositions, etc. As used herein, the term "thermosetting" refers to a resin that irreversibly "sets" upon curing or crosslinking, wherein the polymer chains of the polymer component are joined together by covalent bonds. This property is generally associated with a crosslinking reaction of the composition components, which is often induced, for example, by heating or radiation. The curing or crosslinking reaction can also be carried out under ambient conditions. Once cured or crosslinked, the thermosetting resin will not melt and will not dissolve in solvents when heated. As used herein, the term "thermoplastic" refers to a resin that contains a polymer component that is not joined by covalent bonds and can thus undergo liquid flow when heated and is soluble in solvents.

[0095] As shown above, according to the present invention, an electrodepositable coating composition comprising a water-dispersible, film-forming resin containing ionic salt groups can be deposited onto a substrate by an electrophoretic coating step, wherein the electrodepositable coating composition is deposited onto a metal substrate by electrodeposition.

[0096] The film-forming polymer containing ionic salt groups may comprise a film-forming polymer containing cationic salt groups, which is used in cationic electrodepositable coating compositions. As used herein, the term "cation-containing film-forming polymer" refers to a polymer that includes at least partially neutralized cationic groups, such as sulfonium groups and ammonium groups, which impart a positive charge. The film-forming polymer containing cationic salt groups may comprise active hydrogen functional groups, which include, for example, hydroxyl groups, primary or secondary amine groups, and thiol groups. A film-forming polymer containing cationic salt groups (which comprises active hydrogen functional groups) may be referred to as an active hydrogen-containing, cationic salt group-containing film-forming polymer. Examples of polymers suitable for use as the film-forming polymer containing cationic salt groups include, but are not limited to, alkyd resin polymers, acrylics, polyepoxides, polyamides, polyurethanes, polyureas, polyethers, and polyesters, etc.

[0097] The amount of the film-forming polymer containing cationic salt groups present in the cationic electrodepositable coating composition can be 40% - 90% by weight, such as 50% - 80% by weight, such as 60% - 75% by weight, based on the total weight of the resin solids of the electrodepositable coating composition. As used herein, "resin solids" includes the film-forming polymer containing ionic salt groups, the curing agent, and any additional water-dispersible non-colored component(s) present in the electrodepositable coating composition.

[0098] Optionally, the film-forming polymer containing ionic salt groups can include a film-forming polymer containing anionic salt groups for use in anionic electrodepositable coating compositions. As used herein, the term "film-forming polymer containing anionic salt groups" refers to such anionic polymers that contain at least partially neutralized anionic functional groups, such as carboxylic acid and phosphoric acid groups, which impart a negative charge. The film-forming polymer containing anionic salt groups can include active hydrogen functional groups. A film-forming polymer containing anionic salt groups that includes active hydrogen functional groups can be referred to as an active hydrogen-containing, anionic salt group-containing film-forming polymer.

[0099] The film-forming polymer containing anionic salt groups can include a base-solubilized, carboxylic acid group-containing film-forming polymer such as the reaction product or adduct of a drying oil or semi-drying fatty acid ester with a dicarboxylic acid or acid anhydride; and the reaction product of a fatty acid ester, an unsaturated acid or acid anhydride, and any additional unsaturated modifying material, which is further reacted with a polyol. Also suitable are hydroxyalkyl esters of unsaturated carboxylic acids, at least partially neutralized interpolymers of unsaturated carboxylic acids and at least one other ethylenically unsaturated monomer. Still another suitable anionic electrodepositable resin includes an alkyd resin - aminoplast vehicle, i.e., a vehicle containing an alkyd resin and an amine - aldehyde resin. Another suitable anionic electrodepositable resin composition includes mixed esters of resin polyols. Other acid-functional polymers such as phosphated polyepoxides or phosphated acrylic polymers can also be used. Exemplary phosphated polyepoxides are disclosed in

[0004] -

[0015] of U.S. Patent Application Publication No. 2009-0045071 and

[0014] -

[0040] of U.S. Patent Application Serial No. 13 / 232093, the cited portions of which are hereby incorporated by reference.

[0100] The amount of the film-forming polymer containing anionic salt groups present in the anionic electrodepositable coating composition can be 50% - 90%, such as 55% - 80%, such as 60% - 75%, based on the total weight of the resin solids in the electrodepositable coating composition.

[0101] The electro-depositable coating composition may further comprise a curing agent. The curing agent may react with reactive groups, such as active hydrogen groups, of the film-forming polymer containing ionic salt groups to complete the curing of the coating composition to form a coating. Non-limiting examples of suitable curing agents are at least partially blocked polyisocyanates, aminoplast resins and phenolic resins, such as phenolic condensates, including their allyl ether derivatives.

[0102] The amount of the curing agent present in the cationic electro-depositable coating composition may be 10% - 60% by weight, such as 20% - 50% by weight, such as 25% - 40% by weight, based on the total weight of the resin solids of the electro-depositable coating composition. Optionally, the amount of the curing agent present in the anionic electro-depositable coating composition may be 10% - 50% by weight, such as 20% - 45% by weight, such as 25% - 40% by weight, based on the total weight of the resin solids of the electro-depositable coating composition.

[0103] The electro-depositable coating composition may further comprise other optional ingredients, such as a pigment composition and, if desired, different additives such as fillers, plasticizers, antioxidants, biocides, UV light absorbers and stabilizers, hindered amine light stabilizers, defoamers, fungicides, dispersion aids, flow control agents, surfactants, wetting agents or combinations thereof.

[0104] The electro-depositable coating composition may comprise water and / or one or more organic solvents. The water may be present, for example, in an amount of 40% - 90% by weight, such as 50% - 75% by weight, based on the total weight of the electro-depositable coating composition. If used, the organic solvent is typically present in an amount of less than 10% by weight, such as less than 5% by weight, based on the total weight of the electro-depositable coating composition. The electro-depositable coating composition may be provided specifically in the form of an aqueous dispersion. The total solids content of the electro-depositable coating composition may be 1% - 50% by weight, such as 5% - 40% by weight, such as 5% - 20% by weight, based on the total weight of the electro-depositable coating composition. As used herein, "total solids" refers to the non-volatile content of the electro-depositable coating composition, i.e., such materials that do not volatilize when heated to 110 °C for 15 minutes.

[0105] The cationic electrodepositable coating composition can be deposited onto a conductive substrate as follows: The composition is placed in contact with a conductive cathode and a conductive anode, and the surface to be coated is the cathode. Optionally, the anionic electrodepositable coating composition can be deposited onto a conductive substrate as follows: The composition is placed in contact with a conductive cathode and a conductive anode, and the surface to be coated is the anode. When a sufficient voltage is impressed between the electrodes, an adherent film of the electrodepositable coating composition is deposited onto the cathode or anode, respectively, in a substantially continuous manner. The voltage applied can vary and can be, for example, as low as 1 volt to as high as several thousand volts such as 50 - 500 volts. The current density is typically 1.0 ampere - 15 amperes per square foot (10.8 - 161.5 amperes per square meter) and tends to drop rapidly during the electrodeposition process, indicating the formation of a continuous self-insulating film.

[0106] Once the cationic or anionic electrodepositable coating composition is electrodeposited onto at least a portion of the conductive substrate, the coated substrate can be heated to a certain temperature and for a period of time sufficient to cure the electrodeposited coating on the substrate. For cationic electrodeposition, the coated substrate can be heated to a temperature of 250°F - 450°F (121.1°C - 232.2°C), such as 275°F - 400°F (135°C - 204.4°C), such as 300°F - 360°F (149°C - 180°C). For anionic electrodeposition, the coated substrate can be heated to a temperature of 200°F - 450°F (93°C - 232.2°C), such as 275°F - 400°F (135°C - 204.4°C), such as 300°F - 360°F (149°C - 180°C), such as 200°F - 210.2°F (93°C - 99°C). The cure time will depend on the cure temperature as well as other variables such as the film thickness of the electrodeposited coating, the level and type of catalyst present in the composition, etc. For example, the cure time can be 10 minutes - 60 minutes, such as 20 - 40 minutes. The thickness of the resulting cured electrodeposited coating can be 2 - 50 microns.

[0107] Optionally, as described above, according to the present invention, after the substrate is contacted with the sealant composition, a powder coating composition can then be deposited onto at least a portion of the surface of the substrate. As used herein, "powder coating composition" refers to a coating composition that is completely free of water and / or solvent. Thus, the powder coating compositions disclosed herein are not synonymous with the aqueous and / or solvent-based coating compositions known in the art.

[0108] According to the present invention, the powder coating composition may comprise (a) a film-forming polymer having reactive functional groups; and (b) a curing agent reactive with said functional groups. Examples of powder coating compositions that can be used in the present invention include polyester-based ENVIROCRON series powder coating compositions (commercially available from PPG Industries, Inc.) or epoxy-polyester hybrid powder coating compositions. Alternative examples of powder coating compositions that can be used in the present invention include low-temperature curable thermosetting powder coating compositions comprising (a) at least one tertiary amino urea compound, at least one tertiary amino carbamate compound or a mixture thereof, and (b) at least one film-forming epoxy-containing resin and / or at least one silicone-containing resin (such as those described in U.S. Patent No. 7,470,752, which is assigned to PPG Industries, Inc. and incorporated herein by reference); curable powder coating compositions generally comprising (a) at least one tertiary amino urea compound, at least one tertiary amino carbamate compound or a mixture thereof, and (b) at least one film-forming epoxy-containing resin and / or at least one silicone-containing resin (such as those described in U.S. Patent No. 7,432,333, assigned to PPG Industries, Inc. and incorporated herein by reference); and those comprising a solid particulate mixture of a polymer having reactive groups with a T g of at least 30 °C (such as those described in U.S. Patent No. 6,797,387, which is assigned to PPG Industries, Inc. and incorporated herein by reference).

[0109] After deposition of the powder coating composition, the coating is often heated to cure the deposited composition. This heating or curing operation is often carried out at a temperature of 150 °C - 200 °C, for example 170 °C - 190 °C, for a time of 10 - 20 minutes. According to the present invention, the thickness of the resulting film is 50 microns - 125 microns.

[0110] As described above, according to the present invention, the coating composition can be a liquid coating composition. As used herein, "liquid coating composition" refers to a coating composition that comprises a portion of water and / or solvent. Thus, the liquid coating compositions disclosed herein are synonymous with the aqueous and / or solvent-based coating compositions known in the art.

[0111] According to the present invention, the liquid coating composition can comprise, for example, (a) a film-forming polymer having reactive functional groups; and (b) a curing agent reactive with the functional groups. In other examples, the liquid coating can comprise a film-forming polymer that can react with oxygen in the air or coalesce into a film upon evaporation of water and / or solvent. These film-forming mechanisms may require or be accelerated by applying heat or some type of radiation (such as ultraviolet or infrared). Examples of liquid coating compositions that can be used in the present invention include a series of solvent-based coating compositions, a series of water-based coating compositions, and a series of UV-curable coatings (all commercially available from PPG Industries, Inc.).

[0112] Suitable film-forming polymers that can be used in the liquid coating composition of the present invention can include (poly)esters, alkyd resins, (poly)urethanes, isocyanurates, (poly)ureas, (poly)epoxies, acid anhydrides, acrylates, (poly)ethers, (poly)sulfides, (poly)amines, (poly)amides, (poly)vinyl chlorides, (poly)olefins, (poly)vinylidene fluorides, (poly)siloxanes, or combinations thereof.

[0113] According to the present invention, a substrate that has been contacted with the sealant composition can also be contacted with a primer composition and / or a topcoat composition. The primer coating can be, for example, a chromate primer and a high-performance topcoat. According to the present invention, the primer coating can be a conventional chromate primer coating, such as those obtained from PPG Industries, Inc. (product code 44GN072), or a chromium-free primer such as those obtained from PPG (DESOPRIME CA 7502, DESOPRIME CA 7521, Deft02GN083, Deft02GN084). Alternatively, the primer coating can be a chromium-free primer coating, such as the coating compositions described in U.S. Patent Application Serial No. 10 / 758973, titled "CORROSION RESISTANT COATINGS CONTAINING CARBON" and U.S. Patent Application Serial Nos. 10 / 758972 and 10 / 758972, both titled "CORROSION RESISTANT COATINGS", which are hereby incorporated by reference in their entirety, and the present invention can also use other chromium-free primers known in the art, and they can meet the military requirements of MIL-PRF-85582N class or MIL-PRF-23377N class.

[0114] As described above, the substrate of the present invention may also include a topcoat. As used herein, the term "topcoat" refers to a mixture of one or more binders (which may be organic or inorganic-based polymers or blends of polymers), typically at least one pigment, may optionally include at least one solvent or solvent mixture, and may optionally include at least one curing agent. A topcoat is typically a coating of a single-layer or multi-layer coating system, whose outer surface is exposed to the atmosphere or environment, and whose inner surface is in contact with another coating or polymeric substrate. Examples of suitable topcoats include those conforming to MIL-PRF-85285D, such as those obtained from PPG (Deft 03W127A and Deft 03GY292). According to the present invention, the topcoat may be a high-performance topcoat, such as those obtained from PPG ( ELT.TM.99GY001 and 99W009). However, other topcoats and high-performance topcoats may also be used in the present invention, as will be understood by those skilled in the art referring to the present disclosure.

[0115] According to the present invention, the metal substrate may also include a self-priming topcoat, or an enhanced self-priming topcoat. The term "self-priming topcoat" is also referred to as "direct-to-substrate" or "direct-to-metal" coating, which refers to a mixture of one or more binders (which may be organic or inorganic-based polymers or blends of polymers), typically at least one pigment, may optionally include at least one solvent or solvent mixture, and may optionally include at least one curing agent. The term "enhanced self-priming topcoat" is also referred to as "enhanced direct-to-substrate coating", which refers to a functionalized fluorinated binder such as vinylidene fluoride-alkyl vinyl ether whole or in part blended with one or more other binders (which may be organic or inorganic-based polymers or polymer blends), typically at least one pigment, may optionally include at least one solvent or solvent mixture, and may optionally include at least one curing agent. Examples of self-priming topcoats include those conforming to TT-P-2756A. Examples of self-priming topcoats include those obtained from PPG (03W169 and 03GY369), and examples of enhanced self-priming topcoats include ELT TM / ESPT and product code 97GY121, obtained from PPG. However, other self-priming topcoats and enhanced self-priming topcoats may be used in the coating system according to the present invention, as will be understood by those skilled in the art referring to the present disclosure.

[0116] According to the present invention, the self-priming paint and the enhanced self-priming paint can be directly applied to a sealed substrate. The self-priming paint and the enhanced self-priming paint can optionally be applied to an organic or inorganic polymer coating such as a primer or a paint film. The self-priming paint layer and the enhanced self-priming paint are typically coatings in a single-layer or multi-layer coating system, wherein the outer surface of the coating is exposed to the atmosphere or the environment, and the inner surface of the coating typically contacts the substrate or an optional polymer coating or primer.

[0117] According to the present invention, the topcoat, the self-priming paint and the enhanced self-priming paint can be applied to a sealed substrate in wet or "under-cured" conditions, which dry or cure over time, i.e., the solvent evaporates and / or there is a chemical reaction. The coating can dry or cure naturally or by accelerating means such as an ultraviolet light curing system to form a film or a "cured" paint. The coating can also be applied in a semi- or fully cured state, such as a binder.

[0118] Additionally, colorants and, if desired, different additives such as surfactants, wetting agents or catalysts can be included in the coating composition (electrodepositable, powder or liquid coating composition). As used herein, the term "colorant" means any such substance that imparts color and / or other opacity and / or other visual effects to the composition. Examples of colorants include pigments, dyes and toners, such as those used in the paint industry and / or those listed by the Dry Color Manufacturers Association (DCMA), as well as special effect compositions.

[0119] Generally, the colorant can be present in the coating composition in any amount sufficient to impart the desired visual and / or color effect. The colorant can be present in an amount of 1-65% by weight, such as 3-40% by weight or 5-35% by weight, based on the total weight of the composition.

[0120] For the purposes of the following detailed description, it should be understood that the present invention may take different alternative variations and step sequences, except where there are express contrary provisions. In addition, unless any operating example or otherwise indicated, all numbers such as those representing values, amounts, percentages, ranges, sub-ranges, and fractions may be interpreted as being preceded by the word "about", even if the term does not explicitly appear. Accordingly, unless there is a contrary indication, the numerical parameters set forth in the following specification and the appended claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be construed in light of the number of significant digits reported and by applying ordinary rounding techniques. In the case of closed or open numerical ranges described herein, all numbers, values, amounts, percentages, sub-ranges, and fractions that fall within or are included within the stated numerical range are considered to be expressly included in and part of the initial disclosure of the present application, as if such numbers, values, amounts, percentages, sub-ranges, and fractions were expressly written out in their entirety.

[0121] While the numerical ranges and parameters setting forth the broad scope of the present invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Nevertheless, any numerical value inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0122] As used herein, unless otherwise indicated, plural terms may include their singular counterparts and vice versa, unless otherwise indicated. For example, while "a" cleaning composition, "a" conversion composition, and "a" sealing composition are referred to herein, combinations (i.e., pluralities) of these components may be used. Additionally, in the present application, the use of "or" means "and / or", unless otherwise expressly specified, even though "and / or" may be expressly used in some instances.

[0123] As used herein, "comprising", "containing", and like terms are understood in the context of the present application to be synonymous with "including" and are thus open-ended and do not exclude the presence of additional unrecited and / or unenumerated elements, materials, components, and / or method steps. As used herein, "consisting of" is understood in the context of the present application to exclude the presence of any unspecified elements, components, and / or method steps. As used herein, "consisting essentially of" is understood in the context of the present application to include the recited elements, materials, components, and / or method steps "and those that do not materially affect the basic and novel characteristics(s) described".

[0124] As used herein, the terms "on", "onto", "applied on", "applied onto", "formed on", "deposited on", "deposited onto" mean formed, coated, deposited or provided on a surface, but not necessarily in contact with the surface. For example, a coating "formed on" a substrate does not exclude the presence of one or more other intervening coatings of the same or different composition located between the formed coating and the substrate.

[0125] Unless otherwise disclosed herein, the term "substantially free" when used in reference to the absence of a particular material means that such material, if present in a composition, a bath containing the composition, and / or a layer formed from and containing the composition, is present only in trace amounts of 5 ppm or less, based on the total weight of the composition or layer(s), as appropriate, which excludes any amount of such material that may be present or result from drag-in, dissolution of the substrate(s) and / or apparatus. Unless otherwise disclosed herein, the term "essentially free" when used in reference to the absence of a particular material means that such material, if present in a composition, a bath containing the composition, and / or a layer formed from and containing the composition, is present only in trace amounts of 1 ppm or less, based on the total weight of the composition or layer(s), as appropriate. Unless otherwise disclosed herein, the term "completely free" when used in reference to the absence of a particular material means that such material, if present in a composition, a bath containing the composition, and / or a layer formed from and containing the composition, is not present in the composition, the bath containing the composition, and / or the layer formed from and containing it (i.e., the composition, the bath containing the composition, and / or the layer formed from and containing the composition contains 0 ppm of such material).

[0126] As used herein, "salt" refers to an ionic compound that consists of a metal cation and a non-metal anion and has an overall charge of zero. The salt can be hydrated or anhydrous.

[0127] As used herein, "aqueous composition" refers to a solution or dispersion in a medium that mainly contains water. For example, the amount of water that the aqueous medium can contain is greater than 50 wt%, or greater than 70 wt%, or greater than 80 wt%, or greater than 90 wt%, or greater than 95 wt%, based on the total weight of the medium. The aqueous medium can, for example, consist essentially of water.

[0128] As used herein, "conversion composition" refers to a composition that is capable of reacting with a substrate surface and chemically altering the substrate surface and bonding to it to form a film that provides corrosion protection.

[0129] As used herein, "sealing composition" refers to a composition such as a solution or dispersion that affects the substrate surface or a material deposited on the substrate surface in such a way that the physical and / or chemical properties of the substrate surface are altered (i.e., the composition provides corrosion protection).

[0130] As used herein, the term "oxidizing agent", when used with respect to a component of a sealing composition, refers to a chemical that is capable of oxidizing at least one of the following: a metal present in the substrate that comes into contact with the sealing composition and / or a metal complexing agent present in the sealing composition. As used herein with respect to "oxidizing agent", the phrase "capable of oxidizing" means capable of removing electrons from an atom or molecule present in the substrate or sealing composition, as the case may be, thereby reducing the number of electrons.

[0131] As used herein, the term "transition metal" refers to an element in any of Groups IIIB to XIIB of the CAS version of the Periodic Table of the Elements, excluding the lanthanide series and elements 89 - 103, e.g., in the Handbook of Chemistry and Physics, 63rd Edition (1983), corresponding to Groups 3 to 12 in the actual IUPAC numbering.

[0132] As used herein, the term "transition metal compound" refers to a compound that contains at least one element that is a transition metal of the CAS version of the Periodic Table of the Elements.

[0133] As used herein, the term "Group IA metal" refers to an element that is in Group IA of the CAS version of the Periodic Table of the Elements, as shown, for example, in the Handbook of Chemistry and Physics, 63rd Edition (1983), corresponding to Group 1 in the actual IUPAC numbering.

[0134] As used herein, the term "Group IA metal compound" refers to a compound that includes at least one element that is in Group IA of the CAS version of the Periodic Table of the Elements.

[0135] As used herein, the term "Group IIA metal" refers to an element that is in Group IIA of the CAS version of the Periodic Table of the Elements, as shown, for example, in the Handbook of Chemistry and Physics, 63rd Edition (1983), corresponding to Group 2 in the actual IUPAC numbering.

[0136] As used herein, the term "Group IIA metal compound" refers to a compound that includes at least one element that is in Group IIA of the CAS version of the Periodic Table of the Elements.

[0137] As used herein, the term "Group IIIB metal" refers to yttrium and scandium of the CAS version of the periodic table of the elements, as shown, for example, in Handbook of Chemistry and Physics, 63rd Edition (1983), corresponding to Group 3 of the actual IUPAC numbering. For clarity, the "Group IIIB metals" specifically exclude the lanthanides.

[0138] As used herein, the term "Group IIIB metal compound" refers to a compound that includes at least one element in Group IIIB of the CAS version of the periodic table of the elements, as defined above.

[0139] As used herein, the term "Group IVB metal" refers to an element that is in Group IVB of the CAS version of the periodic table of the elements, as shown, for example, in Handbook of Chemistry and Physics, 63rd Edition (1983), corresponding to Group 4 of the actual IUPAC numbering.

[0140] As used herein, the term "Group IVB metal compound" refers to a compound that includes at least one element in Group IVB of the CAS version of the periodic table of the elements.

[0141] As used herein, the term "Group VB metal" refers to an element that is in Group VB of the CAS version of the periodic table of the elements, as shown, for example, in Handbook of Chemistry and Physics, 63rd Edition (1983), corresponding to Group 5 of the actual IUPAC numbering.

[0142] As used herein, the term "Group VB metal compound" refers to a compound that includes at least one element in Group VB of the CAS version of the periodic table of the elements.

[0143] As used herein, the term "Group VIB metal" refers to an element that is in Group VIB of the CAS version of the periodic table of the elements, as shown, for example, in Handbook of Chemistry and Physics, 63rd Edition (1983), corresponding to Group 6 of the actual IUPAC numbering.

[0144] As used herein, the term "Group VIB metal compound" refers to a compound that includes at least one element in Group VIB of the CAS version of the periodic table of the elements.

[0145] As used herein, the term "Group VIIB metal" refers to an element that is in Group VIB of the CAS version of the Periodic Table of the Elements, as shown, for example, in the Handbook of Chemistry and Physics, 63rd Edition (1983), corresponding to Group 7 of the actual IUPAC numbering.

[0146] As used herein, the term "Group VIIB metal compound" refers to a compound that includes at least one element in Group VIIB of the CAS version of the Periodic Table of the Elements.

[0147] As used herein, the term "Group XII metal" refers to an element that is in Group VIB of the CAS version of the Periodic Table of the Elements, as shown, for example, in the Handbook of Chemistry and Physics, 63rd Edition (1983), corresponding to Group 12 of the actual IUPAC numbering.

[0148] As used herein, the term "Group XII metal compound" refers to a compound that includes at least one element in Group XII of the CAS version of the Periodic Table of the Elements.

[0149] As used herein, the term "lanthanide" refers to elements 57 - 71 of the CAS version of the Periodic Table of the Elements and includes the elemental forms of the lanthanides. According to the present invention, the lanthanides can be those having both the common oxidation states of +3 and +4 (hereinafter referred to as the +3 / +4 oxidation state).

[0150] As used herein, the term "lanthanide compound" refers to a compound that includes at least one of elements 57 - 71 of the CAS version of the Periodic Table of the Elements.

[0151] As used herein, the term "halogen" refers to any one of the elements fluorine, chlorine, bromine, iodine, and astatine of the CAS version of the Periodic Table of the Elements, corresponding to Group VIIA of the Periodic Table.

[0152] As used herein, the term "halide" refers to a compound that includes at least one halogen.

[0153] As used herein, the term "aluminum", when used in reference to a substrate, refers to a substrate made of aluminum and / or an aluminum alloy or containing the same, and an aluminized substrate.

[0154] Pitting corrosion is a locally formed corrosion that creates chambers or holes in the substrate. As used herein, the term "pit" refers to such a chamber or hole that is formed by pitting corrosion and is characterized by (1) a circular, elongated, or irregular appearance when viewed perpendicular to the surface of the test panel, (2) "comet tails," lines, or "halos" (i.e., surface discoloration) diverging from the pit chamber, and (3) the presence of corrosion by-products (e.g., white, light gray, or black granular, powdery, or amorphous material) within or immediately surrounding the pit. The observed surface chambers or holes must exhibit at least two of the above characteristics to be considered corrosion pits. Surface chambers or holes that exhibit only one of these characteristics will require additional analysis before being classified as corrosion pits. When the corrosion by-products are not visible to the naked eye, visual inspection using a microscope at 10X magnification is used to determine the presence of the corrosion by-products.

[0155] Unless otherwise disclosed herein, as used herein, the term "total composition weight," "total weight of the composition," or similar terms refers to the total weight of all components present in the respective composition, including any carriers and solvents.

[0156] In view of the foregoing description, the present invention thus specifically relates to the following aspects 1-26, but is not limited thereto:

[0157] Aspect

[0158] Aspect 1. A conversion composition comprising:

[0159] An aqueous carrier; and

[0160] A trivalent chromium salt in an amount of 0.001 g / L to 20 g / L.

[0161] Aspect 2. The conversion composition according to aspect 1, further comprising an anion suitable for forming a salt with trivalent chromium.

[0162] Aspect 3. The conversion composition according to aspect 1 or aspect 2, further comprising a co-inhibitor.

[0163] Aspect 4. The conversion composition according to aspect 3, further comprising an anion suitable for forming a salt with the co-inhibitor.

[0164] Aspect 5. The conversion composition according to any one of the foregoing aspects, wherein the pH is less than 7.

[0165] Aspect 6. The conversion composition according to any one of aspects 1 to 4, wherein the pH is greater than 6.

[0166] Aspect 7. The conversion composition according to any one of aspects 1 to 4, wherein the pH is greater than 7.

[0167] Aspect 8. A system for treating a metal substrate, comprising:

[0168] a cleaning composition; and

[0169] a conversion composition of any of the foregoing aspects.

[0170] Aspect 9. The system according to aspect 8, wherein the cleaning composition comprises a source of hydroxide and / or a source of phosphate.

[0171] Aspect 10. The system according to aspect 8 or aspect 9, wherein the cleaning composition has a pH less than 7.

[0172] Aspect 11. The system according to any one of aspects 8 to 10, wherein the cleaning composition has a pH greater than 7.

[0173] Aspect 12. The system according to any one of aspects 8 to 11, wherein the cleaning composition further comprises a corrosion inhibitor containing metal cations and / or azoles.

[0174] Aspect 13. The system according to aspect 12, wherein the metal cations include rare earths, Group IA metals, Group IIA metals, Group IIIB metals, and / or Group IVB metals.

[0175] Aspect 14. The system according to aspect 12, wherein the azoles include 2,5-dimercapto-1,3,4-thiadiazole, 1H-benzotriazole, 1H-1,2,3-triazole, 2-amino-5-mercapto-1,3,4-thiadiazole, and / or 2-amino-1,3,4-thiadiazole.

[0176] Aspect 15. The system according to any one of aspects 8 to 14, wherein the cleaning composition comprises a deoxidizer.

[0177] Aspect 16. The system according to any one of aspects 8 to 15, further comprising a chemical deoxidizer and / or a mechanical deoxidizer.

[0178] Aspect 17. The system according to any one of aspects 8 to 16, further comprising a sealing composition.

[0179] Aspect 18. The system according to aspect 17, wherein the sealing composition comprises a source of lithium.

[0180] Aspect 19. The system according to aspect 18, wherein, based on the total weight of the sealing composition, the source of lithium comprises a lithium salt present in the sealing composition in an amount of 50 ppm to 30,000 ppm (compound).

[0181] Aspect 20. The system according to any one of aspects 17 to 19, wherein the sealing composition further comprises a source of carbonate, a source of hydroxide, or a combination thereof.

[0182] Aspect 21. The system according to any one of aspects 17 to 20, wherein the sealing composition further comprises a Group IA metal source other than lithium, a Group VB metal source, a Group VIB metal source, a corrosion inhibitor, an indicator compound, or a combination thereof.

[0183] Aspect 22. The system according to any one of aspects 17 to 21, wherein the pH of the sealing composition is from 9.5 to 12.5.

[0184] Aspect 23. A method of treating a substrate, comprising:

[0185] contacting at least a portion of the surface of the substrate with a cleaning composition; and

[0186] contacting at least a portion of the surface contacted with the cleaning composition with a conversion composition according to any one of aspects 1 to 7.

[0187] Aspect 24. The method according to aspect 23, wherein the substrate is treated with a system according to any one of aspects 8 to 22.

[0188] Aspect 25. A substrate treated with a system according to any one of aspects 8 to 22, preferably treated by the method according to any one of aspects 23 or 24.

[0189] Aspect 26. The substrate according to aspect 25, wherein the substrate further comprises a primer layer and / or a topcoat layer.

[0190] Although the specific features of the present invention have been described above for purposes of illustration, it will be apparent to those skilled in the art that many changes may be made to the details of the coating compositions, coatings and methods disclosed herein without departing from the scope of the appended claims.

[0191] The following examples illustrate the invention and are not to be considered as limiting the invention to their details. All parts and percentages throughout the examples and the entire application document are by weight, unless otherwise indicated.

[0192] Examples

[0193] Using the ingredients shown in Table 2, a cleaning composition of Example A was prepared by dissolving the ingredients in deionized water using a stirring plate with gentle stirring.

[0194] Using the ingredients shown in Table 2, a sealing composition of Example B was prepared by dissolving lithium carbonate in deionized water using a stirring plate with gentle stirring.

[0195] The hermetic composition of Example C was prepared by dissolving lithium carbonate in deionized water using a magnetic stirrer with gentle stirring with the ingredients shown in Table 2. Then, 2,5-dimercapto-1,3,4-thiadiazole was added, and then catechol violet was added and dissolved with gentle stirring as described above.

[0196] Table 2. Compositions

[0197]

[0198] For Examples 1-7, unless otherwise stated, each bath was 12 L.

[0199] Example 1

[0200] Three bare aluminum 2024T3 substrates (Priority Metals, Orange County, CA), each with dimensions of 3"×10"×0.032", were manually wiped with methyl ethyl ketone (100%) and a disposable cloth and air-dried, followed by chemical cleaning. At 55 °C, with stirring, each plate was immersed in a bath containing SOCOCLEAN A3432 (a cleaning composition commercially available from Socomore, prepared according to the manufacturer's instructions) for 10 minutes. Then each plate was spray-rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinsing for 2 minutes. After immersion rinsing, at 50 °C, with stirring, each plate was immersed in a bath containing SOCOSURF Al858 - Al806 (a deoxidizer commercially available from Socomore, prepared according to the manufacturer's instructions) for 5 minutes. Then each plate was spray-rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinsing for 2 minutes. After immersion rinsing, at 40 °C, each plate was immersed in a bath containing SOCOSURF TCS (a trivalent chromium-containing conversion composition commercially available from Socomore, prepared according to the manufacturer's instructions) for 5 minutes without stirring. Then each plate was spray-rinsed with deionized water for 2 minutes and then immediately immersed in deionized water rinsing for 2 minutes. Before testing, the plates were air-dried overnight under ambient conditions.

[0201] Example 2

[0202] Three aluminum 2024T3 bare substrates (Priority Metals, Orange County, CA) each with dimensions of 3"×10"×0.032" were hand wiped with methyl ethyl ketone (100%) and a disposable cloth and air dried, and then chemically cleaned. At 55 °C, with stirring, each plate was immersed in a bath containing SOCOCLEAN A3432 (a cleaning composition commercially available from Socomore, prepared according to the manufacturer's instructions) for 10 minutes. Then each plate was spray rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinse for 2 minutes. After immersion rinsing, at 50 °C, with stirring, each plate was immersed in a bath containing SOCOSURF Al858 - Al806 (a deoxidizer commercially available from Socomore, prepared according to the manufacturer's instructions) for 5 minutes. Then each plate was spray rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinse for 2 minutes. After immersion rinsing, at 40 °C each plate was immersed in a bath containing SOCOSURF TCS (a trivalent chromium - containing conversion composition commercially available from Socomore, prepared according to the manufacturer's instructions) for 5 minutes without stirring. Then each plate was spray rinsed with deionized water for 2 minutes and then immediately immersed in deionized water rinse for 2 minutes. Then at 25 °C, with stirring, each plate was immersed in a bath containing SOCOSURF PACS (a sealing composition containing H202, commercially available from Socomore, prepared according to the manufacturer's instructions) for 5 minutes. Before testing, the plates were air dried overnight under ambient conditions.

[0203] Example 3

[0204] Three aluminum 2024T3 bare substrates (Priority Metals, Orange County, CA) each with dimensions of 3"×10"×0.032" were hand wiped with methyl ethyl ketone (100%) and a disposable cloth and air dried, and then chemically cleaned. At 55 °C, with stirring, each plate was immersed in a bath containing SOCOCLEAN A3432 (a cleaning composition commercially available from Socomore, prepared according to the manufacturer's instructions) for 10 minutes. Then each plate was spray rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinsing for 2 minutes. After immersion rinsing, at 50 °C, with stirring, each plate was immersed in a bath containing SOCOSURF Al858 - Al806 (a deoxidizer commercially available from Socomore, prepared according to the manufacturer's instructions) for 5 minutes. Then each plate was spray rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinsing for 2 minutes. After immersion rinsing, at 40 °C, each plate was immersed in a bath containing SOCOSURF TCS (a trivalent chromium-containing conversion composition commercially available from Socomore, prepared according to the manufacturer's instructions) for 5 minutes without stirring. Then each plate was spray rinsed with deionized water for 2 minutes and then immediately immersed in deionized water rinsing for 2 minutes. Then each plate was immersed in a bath containing the sealing composition of Example B for 2 minutes at ambient temperature without stirring. Before testing, the plates were air dried overnight under ambient conditions.

[0205] Example 4

[0206] Three bare aluminum 2024T3 substrates (Priority Metals, Orange County, CA) each having dimensions of 3"×10"×0.032" were hand wiped with methyl ethyl ketone (100%) and a disposable cloth and air dried, and then chemically cleaned. At 55 °C, with stirring, each plate was immersed in a bath containing SOCOCLEAN A3432 (a cleaning composition commercially available from Socomore, prepared according to the manufacturer's instructions) for 10 minutes. Then each plate was spray rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinsing for 2 minutes. After immersion rinsing, at 50 °C, with stirring, each plate was immersed in a bath containing SOCOSURF A1858 - A1806 (a deoxidizer commercially available from Socomore, prepared according to the manufacturer's instructions) for 5 minutes. Then each plate was spray rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinsing for 2 minutes. After immersion rinsing, at 40 °C, each plate was immersed in a bath containing SOCOSURF TCS (a trivalent chromium-containing conversion composition commercially available from Socomore, prepared according to the manufacturer's instructions) for 5 minutes without stirring. Then each plate was spray rinsed with deionized water for 2 minutes and then immediately immersed in deionized water rinsing for 2 minutes. Then each plate was immersed in a bath containing the sealing composition of Example C at ambient temperature for 2 minutes without stirring. Before testing, the plates were air dried overnight under ambient conditions.

[0207] Example 5

[0208] Three bare aluminum 2024T3 substrates (Priority Metals, Orange County, CA) each having dimensions of 3"×10"×0.032" were hand wiped with methyl ethyl ketone (100%) and a disposable cloth and air dried, and then chemically cleaned. Each plate was immersed in a bath containing the cleaning composition of Example A at ambient temperature with stirring for 4.5 minutes. Then each plate was spray rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinsing for 2 minutes. After immersion rinsing, at 40 °C, then each plate was immersed in a bath containing SOCOSURF TCS (a trivalent chromium-containing conversion composition commercially available from Socomore, prepared according to the manufacturer's instructions) for 5 minutes without stirring. Then each plate was spray rinsed with deionized water for 2 minutes and then immediately immersed in deionized water rinsing for 2 minutes. Then each plate was immersed in a bath containing the sealing composition of Example B at ambient temperature for 2 minutes without stirring.

[0209] Before testing, the plates were air dried overnight under ambient conditions.

[0210] Example 6

[0211] Three bare aluminum 2024T3 substrates (Priority Metals, Orange County, CA) each with dimensions of 3" × 10" × 0.032" were manually wiped with methyl ethyl ketone (100%) and a disposable cloth and air-dried, followed by chemical cleaning. Each plate was immersed in a bath containing the cleaning composition of Example A for 4.5 minutes at ambient temperature with stirring. Then each plate was spray-rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinse for 2 minutes. After immersion rinsing, at 40 °C, each plate was immersed in a bath containing SOCOSURF TCS (a trivalent chromium-containing conversion composition, commercially available from Socomore, prepared according to the manufacturer's instructions) for 5 minutes without stirring. Then each plate was spray-rinsed with deionized water for 2 minutes and then immediately immersed in deionized water rinse for 2 minutes. Then each plate was immersed in a bath containing the sealing composition of Example C for 2 minutes at ambient temperature without stirring.

[0212] Before testing, the plates were air-dried overnight under ambient conditions.

[0213] Example 7

[0214] Three bare aluminum 2024T3 substrates (Priority Metals, Orange County, CA) each with dimensions of 3" × 10" × 0.032" were manually wiped with methyl ethyl ketone (100%) and a disposable cloth and air-dried, followed by chemical cleaning. Each plate was immersed in a bath containing the cleaning composition of Example A for 4.5 minutes at ambient temperature with stirring. Then each plate was spray-rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinse for 2 minutes. After immersion rinsing, at 40 °C, each plate was immersed in a bath containing SOCOSURF TCS (a trivalent chromium-containing conversion composition, commercially available from Socomore, prepared according to the manufacturer's instructions) for 5 minutes without stirring. Then each plate was spray-rinsed with deionized water for 2 minutes and then immediately immersed in deionized water rinse for 2 minutes. Before testing, the plates were air-dried overnight under ambient conditions.

[0215] Example 8

[0216] A 3"×10"×0.032" aluminum 2024T3 bare substrate was hand wiped with methyl ethyl ketone (100%) and a disposable cloth and air dried, and then chemically cleaned. At 55 °C, the plate was immersed in a 5-gallon bath of a cleaner solution containing Ridonlene 298 (commercially available from Henkel AG & Co., prepared according to the manufacturer's instructions at 1 part concentrate: 9 parts tap water, v / v) with gentle stirring for 2 minutes. Then at ambient temperature, it was immersed in tap water rinse with gentle stirring for 1 minute, followed by a 10-second cascade tap water rinse. At ambient temperature, the plate was immersed in a 5-gallon bath containing Turco Deoxidizer 6 / 16 deoxidizing solution (commercially available from Henkel AG & Co., prepared according to the manufacturer's instructions at 5 parts 6 / 16: 10 parts nitric acid: 85 parts tap water (v / v)) for 2.5 minutes, then immersed in tap water rinse with gentle stirring at ambient temperature for one minute, followed by a 10-second cascade rinse. Then at ambient temperature, the plate was immersed in a bath containing Alodine 1200 (a conversion composition containing hexavalent chromium, commercially available from Henkel AG & Co., prepared according to the manufacturer's instructions) for 2.5 minutes without stirring. After immersion in the conversion composition bath, at ambient temperature, the plate was subjected to immersion rinse in deionized water with gentle stirring for 1 minute, followed by a 10-second cascade deionized water rinse. Before testing, the plate was air dried overnight under ambient conditions.

[0217] Neutral salt spray test

[0218] The plate was placed in a neutral salt spray chamber operating according to ASTM B117 and exposed for 7 days. The corrosion performance was evaluated according to MIL-C-5541, where any pitting, scratches, metal defects or machining fixture hold areas near the edges were ignored / not counted. The data is reported in Table 3. For Examples 1 - 7, the reported number of pits is the average of three plates. For Example 8, the number of pits reported is for a single plate.

[0219]

[0220]

[0221] Example 9

[0222] Three aluminum 2024T3 bare substrates (Priority Metals, Orange County, CA) each having dimensions of 3"×10"×0.032" were hand wiped with methyl ethyl ketone (100%) and a disposable cloth and air dried, and then chemically cleaned. At 55 °C, with stirring, each plate was immersed in a bath containing SOCOCLEAN A3432 (a cleaning composition commercially available from Socomore, prepared according to the manufacturer's instructions) for 10 minutes. Then each plate was spray rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinsing for 2 minutes. After immersion rinsing, at 30 °C, with stirring, each plate was immersed in a bath containing SOCOSURF Al858 - Al806 (a deoxidizer commercially available from Socomore, prepared according to the manufacturer's instructions) for 6 minutes. Then each plate was spray rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinsing for 2 minutes. After immersion rinsing, each plate was immersed in a bath containing SURTEC 650 (a trivalent chromium conversion composition commercially available from Surtec, prepared according to the manufacturer's instructions) at 27 °C for 5 minutes without stirring. Then each plate was immersion rinsed with deionized water for 2 minutes and then immediately immersed in deionized water rinsing for 2 minutes. Before testing, the plates were air dried overnight under ambient conditions.

[0223] Example 10

[0224] Three bare aluminum 2024T3 substrates (Priority Metals, Orange County, CA) each with dimensions of 3"×10"×0.032" were hand wiped with methyl ethyl ketone (100%) and disposable cloth and air dried, and then chemically cleaned. At 55 °C, with stirring, each plate was immersed in a bath containing SOCOCLEAN A3432 (a cleaning composition commercially available from Socomore, prepared according to the manufacturer's instructions) for 10 minutes. Then each plate was spray rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinse for 2 minutes. After immersion rinse, at 30 °C, with stirring, each plate was immersed in a bath containing SOCOSURF Al858 - Al806 (a deoxidizer commercially available from Socomore, prepared according to the manufacturer's instructions) for 6 minutes. Then each plate was spray rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinse for 2 minutes. After immersion rinse, each plate was immersed in a bath containing SURTEC 650 (a trivalent chromium - containing conversion composition commercially available from Surtec, prepared according to the manufacturer's instructions) for 5 minutes at 30 °C without stirring. Then at 30 °C, with stirring, each plate was immersed in deionized water for immersion rinse for 2 minutes and then immediately immersed in a bath containing SOCOSURF PACS (a sealing composition containing H202, commercially available from Socomore, prepared according to the manufacturer's instructions) for 5 minutes. Before testing, the plates were air dried overnight under ambient conditions.

[0225] Example 11

[0226] Three bare aluminum 2024T3 substrates (Priority Metals, Orange County, CA) each with dimensions of 3" × 10" × 0.032" were manually wiped with methyl ethyl ketone (100%) and a disposable cloth and air dried, and then chemically cleaned. At 55 °C, with stirring, each plate was immersed in a bath containing SOCOCLEAN A3432 (a cleaning composition commercially available from Socomore, prepared according to the manufacturer's instructions) for 10 minutes. Then each plate was spray rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinsing for 2 minutes. After immersion rinsing, at 30 °C, with stirring, each plate was immersed in a bath containing SOCOSURF Al858 - Al806 (a deoxidizer commercially available from Socomore, prepared according to the manufacturer's instructions) for 6 minutes. Then each plate was spray rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinsing for 2 minutes. After immersion rinsing, at 30 °C, each plate was immersed in a bath containing SURTEC 650 (a trivalent chromium - containing conversion composition commercially available from Surtec, prepared according to the manufacturer's instructions) for 5 minutes without stirring. Then each plate was immersion rinsed with deionized water for 2 minutes and then immersed in a bath containing the sealing composition of Example B at ambient temperature for 1 minute without stirring. Before testing, the plates were air dried overnight under ambient conditions.

[0227] Example 12

[0228] Three bare aluminum 2024T3 substrates (Priority Metals, Orange County, CA) each with dimensions of 3" × 10" × 0.032" were manually wiped with methyl ethyl ketone (100%) and a disposable cloth and air dried, and then chemically cleaned. Each plate was immersed in a bath containing the cleaning composition of Example A at ambient temperature with stirring for 1 minute. Then each plate was spray rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinsing for 2 minutes. After immersion rinsing, at 30 °C, each plate was immersed in SURTEC 650 (a trivalent chromium - containing conversion composition commercially available from Surtec, prepared according to the manufacturer's instructions) for 6 minutes without stirring. Then each plate was immersion rinsed with deionized water for 2 minutes and then immediately immersed in deionized water for a second time for 2 minutes. Before testing, the plates were air dried overnight under ambient conditions.

[0229] Example 13

[0230] Three bare aluminum 2024T3 substrates (Priority Metals, Orange County, CA) each having dimensions of 3" × 10" × 0.032" were hand wiped with methyl ethyl ketone (100%) and a disposable cloth and air dried, and then chemically cleaned. Each plate was immersed in a bath containing the cleaning composition of Example A for 3 minutes at ambient temperature with stirring. Then each plate was spray rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinse for 2 minutes. After the immersion rinse, each plate was immersed in SURTEC 650 (a trivalent chromium-containing conversion composition commercially available from Surtec and prepared according to the manufacturer's instructions) at 30 °C for 6 minutes without stirring. Then each plate was immersed in deionized water rinse for 2 minutes and then immediately immersed in deionized water for a second time for 2 minutes. Before testing, the plates were air dried overnight under ambient conditions.

[0231] Example 14

[0232] Three bare aluminum 2024T3 substrates (Priority Metals, Orange County, CA) each having dimensions of 3" × 10" × 0.032" were hand wiped with methyl ethyl ketone (100%) and a disposable cloth and air dried, and then chemically cleaned. Each plate was immersed in a bath containing the cleaning composition of Example A for 6 minutes at ambient temperature with stirring. Then each plate was spray rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinse for 2 minutes. After the immersion rinse, each plate was immersed in SURTEC 650 (a trivalent chromium-containing conversion composition commercially available from Surtec and prepared according to the manufacturer's instructions) at 30 °C without stirring. Then each plate was immersed in deionized water rinse for 2 minutes and then immediately immersed in deionized water for a second time for 2 minutes. Before testing, the plates were air dried overnight under ambient conditions.

[0233] Example 15

[0234] Three aluminum 2024T3 bare substrates (Priority Metals, Orange County, CA) each with dimensions of 3"×10"×0.032" were hand wiped with methyl ethyl ketone (100%) and a disposable cloth and air dried, and then chemically cleaned. At 55 °C, with stirring, each plate was immersed in a bath containing SOCOCLEAN A3432 (a cleaning composition commercially available from Socomore, prepared according to the manufacturer's instructions) for 10 minutes. Then each plate was spray rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinse for 2 minutes. After immersion rinsing, at 27 °C, with stirring, each plate was immersed in a bath containing SMUTGO (a deoxidizer commercially available from Henkel, prepared according to the manufacturer's instructions) for 1 minute. Then each plate was spray rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinse for 2 minutes. After immersion rinsing, then each plate was immersed in SURTEC 650 (a trivalent chromium-containing conversion composition commercially available from Surtec, prepared according to the manufacturer's instructions) at 27 °C for 5 minutes without stirring. Then each plate was immersion rinsed with deionized water for 2 minutes and then immediately immersed in a second deionized water rinse for 2 minutes. Before testing, the plates were air dried overnight under ambient conditions.

[0235] Example 16

[0236] Three bare aluminum 2024T3 substrates (Priority Metals, Orange County, CA) each having dimensions of 3"×10"×0.032" were hand wiped with methyl ethyl ketone (100%) and a disposable cloth and air dried, and then chemically cleaned. At 55 °C, with stirring, each plate was immersed in a bath containing SOCOCLEAN A3432 (a cleaning composition commercially available from Socomore, prepared according to the manufacturer's instructions) for 10 minutes. Then each plate was spray rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinse for 2 minutes. After immersion rinse, at 27 °C, with stirring, each plate was immersed in a bath containing SMUTGO (a deoxidizer commercially available from Henkel, prepared according to the manufacturer's instructions) for 1 minute. Then each plate was spray rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinse for 2 minutes. After immersion rinse, then each plate was immersed in SURTEC 650 (a trivalent chromium-containing conversion composition commercially available from Surtec, prepared according to the manufacturer's instructions) at 30 °C for 5 minutes without stirring. Then each plate was immersion rinsed with deionized water for 2 minutes and then, at 30 °C, immediately immersed in a bath containing SOCOSURF PACS (a sealing composition containing H202, commercially available from Socomore, prepared according to the manufacturer's instructions) for 5 minutes with stirring. Before testing, the plates were air dried overnight under ambient conditions.

[0237] Example 17

[0238] Three bare substrates of aluminum 2024T3 (Priority Metals, Orange County, CA) each having dimensions of 3"×10"×0.032" were hand wiped with methyl ethyl ketone (100%) and a disposable cloth and air dried, and then chemically cleaned. At 55 °C, with stirring, each plate was immersed in a bath containing SOCOCLEAN A3432 (a cleaning composition commercially available from Socomore, prepared according to the manufacturer's instructions) for 10 minutes. Then each plate was spray rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinse for 2 minutes. After immersion rinse, at 27 °C, with stirring, each plate was immersed in a bath containing SMUTGO (a deoxidizer commercially available from Henkel, prepared according to the manufacturer's instructions) for 1 minute. Then each plate was spray rinsed with deionized water for 30 seconds and then immediately immersed in deionized water rinse for 2 minutes. After immersion rinse, then each plate was immersed in SURTEC 650 (a trivalent chromium-containing conversion composition commercially available from Surtec, prepared according to the manufacturer's instructions) at 30 °C for 5 minutes without stirring. Then each plate was immersion rinsed with deionized water for 2 minutes and then immersed in a bath containing the sealing composition of Example B at ambient temperature for 1 minute without stirring. Before testing, the plates were air dried overnight under ambient conditions.

Claims

1. A system for treating a metal substrate, comprising: an alkaline cleaning composition; a conversion composition comprising trivalent chromium cations in an amount of 0.001 g / L to 20 g / L of the conversion composition and a co-inhibitor metal salt in an amount of 0.001 g / L to 20 g / L of the conversion composition, and the pH of the conversion composition is 1.5 to 6.9; and a sealing composition comprising lithium cations and having a pH of 9.5 to 12.5, and based on the total weight of the sealing composition, the amount of lithium cations is 5 ppm to 5500 ppm (as metal cations).

2. The system according to claim 1, wherein the alkaline cleaning composition comprises a source of hydroxide and / or a source of phosphate.

3. The system according to claim 2, wherein the source of hydroxide is present in an amount of 0.05 g / 1000 g to 25 g / 1000 g of the alkaline cleaning composition, and / or the source of phosphate is present in an amount of 50 g / 1000 g to 100 g / 1000 g of the alkaline cleaning composition.

4. The system according to claim 1, wherein the pH of the alkaline cleaning composition is 7 to 13.

5. The system according to claim 1, wherein the alkaline cleaning composition comprises a corrosion inhibitor, and the corrosion inhibitor comprises metal cations and / or azoles.

6. The system according to claim 5, wherein the corrosion inhibitor is present in an amount of 0.01 g / L to 25 g / L of the alkaline cleaning composition.

7. The system according to claim 1, wherein the conversion composition comprises anions suitable for forming salts with trivalent chromium cations.

8. The system according to claim 1, wherein the sealing composition further comprises carbonates, hydroxides or a combination thereof.

9. The system according to claim 1, wherein the sealing composition further comprises azoles and / or indicator compounds.

10. The system according to claim 1, further comprising a chemical deoxidizer.

11. A substrate obtainable by the system according to claim 1.

12. A method for treating a substrate, comprising: contacting the surface of the substrate with an alkaline cleaning composition; contacting the substrate surface with a conversion composition comprising trivalent chromium cations in an amount of 0.001 g / L to 20 g / L of the conversion composition and a co-inhibitor metal salt in an amount of 0.001 g / L to 20 g / L of the conversion composition, and the pH of the conversion composition is 1.5 to 6.9; and contacting the substrate surface with a sealing composition comprising lithium cations and having a pH of 9.5 to 12.5, and based on the total weight of the sealing composition, the amount of lithium cations is 5 ppm to 5500 ppm (as metal cations).

13. A substrate obtainable by the method according to claim 12.

14. The substrate according to claim 13, wherein after 7 days of exposure in a neutral salt spray chamber operated according to ASTM B117, the number of pockmarks on the substrate surface of the substrate contacted with the sealing composition is at least 40% less than that of the substrate not treated with the sealing composition.

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