KR20140069268A - Acid cleaners for metal substrates and associated methods for cleaning and coating metal substrates - Google Patents

Abstract

There is provided a method of cleaning and coating a metal substrate comprising contacting the metal substrate with an acid and subsequently contacting the washed substrate with an electrodepositable coating composition comprising a film forming polymer and a corrosion inhibitor, .

Description

FIELD OF THE INVENTION [0001] The present invention relates to a method of cleaning and coating a metal substrate,

The present invention relates to pickling agents for metal substrates and to related methods for cleaning metal substrates with the pickling agent before application of the pretreatment composition and / or the electrodepositable coating composition.

It is common to use protective coatings on metal substrates for improved corrosion resistance and paint adhesion. Conventional techniques for coating such substrates include techniques involving pretreating the metal substrate with a pretreatment composition and / or an electrodepositable coating composition.

In certain embodiments, the present invention provides a process for preparing a composition comprising: (a) contacting a substrate with an acid; (B) then mixing said substrate with (i) a film-forming polymer; And (ii) an antistatic coating composition comprising a corrosion inhibitor, wherein contacting the substrate with the pretreatment composition prior to step (b) is not included.

For the following detailed description, it is to be understood that the present invention may take various alternative changes and step sequences, except where explicitly stated to the contrary. Moreover, it should be understood that all numbers expressing quantities of ingredients used in the specification and claims, for example, in addition to any executive embodiment or otherwise indicated, are to be understood as being modified in all instances by the term "about" . Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the properties sought to be obtained by the present invention. Each numerical parameter should be interpreted as applying at least the ordinary rounding technique in light of the number of significant digits reported, not as an attempt to limit the application of equivalence to the claims.

Although the numerical ranges and parameters listing the broad scope of the invention are approximations, the numerical values listed in the specific embodiments are reported as precisely as possible. However, any numerical value inherently contains some error that necessarily arises from the standard deviation found in each test measurement.

Furthermore, any numerical range recited in the present invention is intended to include all sub-ranges included in the above range. For example, a range of "1 to 10" would include all subranges having a minimum value between 1 (inclusive) and 10 (inclusive), i.e., a minimum value of 1 and a maximum value of 10 or less.

In this application, the use of the singular includes the plural and the plural includes the singular, unless specifically stated otherwise. Also, in this application, the use of "or" means "and / or" unless expressly specified otherwise, although "and / or"

Certain embodiments of the present invention are directed to a method of cleaning the substrate by contacting the metal substrate with an acid.

The pickled substrate may then be contacted with the pretreatment composition, in certain embodiments. In some of these embodiments, the pretreatment composition comprises a Group IIIB and / or Group IVB metal compound wherein the citric acid cleanser acts to provide increased deposition of Group IIIB and / or Group IVB metals on the surface of the metal substrate Wherein the increased metal content serves to improve corrosion resistance.

In other specific embodiments, a film forming composition, such as an electrodepositable coating composition, may be applied over the pickled and optionally pretreated substrate. In these embodiments, the acid is washed with a coated, un-cleaned substrate or alkaline detergent and provides improved corrosion protection to the coated substrate compared to the coated substrate as described above.

In another specific embodiment, a film forming composition, such as an electrodepositable coating composition, may be applied over the pickled substrate without first contacting the substrate with the pretreatment composition. In some of these embodiments, the acid acts to improve the corrosion resistance of the pickled and electrocoated substrate as compared to a substrate coated with an untreated substrate or an alkaline detergent and electrocoated as described above.

Each of these embodiments is disclosed below:

materials

Suitable substrates that can be cleaned and coated in accordance with the present invention include, but are not limited to, metal substrates, metal alloy substrates, and / or metallized substrates, such as nickel plated plastic. In some embodiments, the metal or metal alloy may be aluminum and / or steel. For example, the steel substrate may be cold rolled steel, electro-galvanized steel, and hot-dip galvanized steel. Furthermore, in some embodiments, the substrate may be part of a vehicle, such as a vehicle body (e.g., but not limited to a door, a body panel, a trunk deck lid, a roof panel, a hood and / . ≪ / RTI > As used herein, "vehicle" or variations thereof include, but are not limited to, civil, commercial, and military land vehicles, such as cars, motorcycles and trucks.

wash

In certain embodiments, the substrate may be contacted with the acid prior to contacting the pretreatment composition and / or the electrodepositable coating composition.

While not wishing to be bound by any theory, it is believed that the acid etches the substrate to provide increased surface area to the substrate. The increased surface area is believed to provide improved adhesion between the substrate and subsequently applied coating materials, which is believed to improve corrosion resistance on the coated panel. In addition, increased etching of the substrate material is believed to allow increased deposition of metal from the pretreatment composition (if used), which is also believed to increase corrosion resistance to the coated panel. Furthermore, increased etching of the substrate material allows for increased deposition of metal from the electrodepositable coating composition at the interface between the electrodepositable coating composition (if used) and the substrate, It is possible to provide a greater corrosion resistance.

In certain embodiments, the acid comprises a single acid, while in other embodiments, the acid comprises a mixture of acids.

In certain embodiments, the acid comprises a weak acid, while in other embodiments the acid comprises a strong acid. A weak acid, by definition, is an acid that is incompletely dissociated (ie, does not release all its hydrogen in solution), whereas a strong acid is an acid that is completely ionized in an aqueous solution (ie, when dissolved in water, Lt; / RTI >

In another embodiment, the acid comprises an organic acid. Organic compounds, by definition, are organic compounds having acidic properties. Exemplary organic acids include uric acid, sulfonic acids, and carboxylic acids including lactic, formic, citric, and oxalic acids, as well as mixtures thereof.

In another embodiment, the acid comprises an inorganic acid. The inorganic acid is, by definition, an acid derived from an inorganic compound. Exemplary inorganic acids include hydrochloric acid, sulfuric acid, boric acid, phosphoric acid, hydrofluoric acid, hydrobromic acid, nitric acid, and mixtures thereof.

In another embodiment, the acid may comprise any combination of one or more organic acids and / or inorganic acids.

In some of these embodiments, the carboxylic acid selected for use in the compositions disclosed herein has a water solubility of > 1 g / L at 20 ° C. Suitable carboxylic acids for use include, for example, monocarboxylic acids such as formic acid, acetic acid, propionic acid, methyl acetic acid, butyric acid, ethylacetic acid, n-valeric acid, n-butanecarboxylic acid, acrylic acid, propiolic acid, methacrylic acid, , Stearic acid, oleic acid, linoleic acid, and linolenic acid; Dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, leparinic acid, sebacic acid, maleic acid, and fumaric acid; Aliphatic carboxylic acids such as aliphatic carboxylic acids such as glycolic acid, lactic acid, tartronic acid, glyceric acid, malic acid, tartaric acid, citramalic acid, citric acid, isocitric acid, leucic acid, mevalonic acid, pantothenic acid, Acid, cerebromic acid, quinic acid, and sikimic acid; It is possible to use aromatic hydroxy acids such as salicylic acid, creosotic acid, vanillic acid, sicric acid, pyrocatechic acid, resorcylic acid, protocatechuic acid, gentisic acid, orsellic acid, gallic acid, mandelic acid, , Melilotic acid, phthalic acid, cumaric acid, umbellic acid, caffeic acid, ferulic acid, and synaptic acid. Mixtures of any of the above acids may also be used.

In certain embodiments, the acid is incorporated into an acid cleansing agent which may also include other components such as water, surfactants and / or buffers, including commercially available surfactants and / or buffers.

In another particular embodiment, the substrate treated according to the method of the present invention may be washed first to remove grease, dust, or other foreign material. This is often accomplished using a mild or strong alkaline detergent, such as a commercially available detergent as is commonly used in metal pretreatment processes. Examples of suitable alkaline detergents for use in the present invention include Chemkleen 163, Chemclin 177, Chemclin 2010LP, and Chemclin 490MX, each of which is available from PPG Industries, Inc., < RTI ID = 0.0 > ). ≪ / RTI > In certain embodiments, surfactants may also be included in an 181 LP that is commercially available from an alkaline detergent, for example, Pfizer Industries, Inc. Such detergents are often followed by water washing and / or followed by water washing. After cleaning, the substrate material may be thoroughly rinsed with deionized water.

In some of these embodiments, the alkaline detergent is applied to the substrate prior to the acidic detergent, while in other embodiments the acid detergent is applied to the substrate prior to the alkaline detergent.

Pretreatment

In certain embodiments of the method of the present invention, after contacting the substrate with the acid, it may then be contacted with the pretreatment composition. As used herein, the term "pretreatment composition" refers to a composition that reacts with the substrate surface upon contact with the substrate, chemically modifies the substrate surface and bonds to the surface to form a protective layer.

In another specific embodiment of the present invention, the pretreatment composition comprises Group IIIB and / or Group IVB metal compounds.

In certain embodiments, the pretreatment composition comprises the carrier, often an aqueous medium, such that the composition is in the form of a solution or dispersion of Group IIIB or Group IVB metal compounds in the carrier. In such an embodiment, the solution or dispersion may be applied to the substrate by any of a variety of known techniques, such as submerging or immersion, spraying, intermittent spraying, submersion followed by submersion, submersion, brushing or roll- . ≪ / RTI > In certain embodiments, the solution or dispersion is present at a temperature in the range of 60 to 150 ° F (15 to 65 ° C) when applied to a metal substrate. The contact time is often 10 seconds to 5 minutes, for example 30 seconds to 2 minutes.

As used herein, the term "Group IIIB and / or IVB metal" refers to a group IIIB of the Periodic Table of the CAS elements, such as that shown in the Handbook of Chemistry and Physics, 63rd edition (1983) Refers to an element in group IVB. If applicable, the metal itself may be used. In certain embodiments, Group IIIB and / or Group IVB metal compounds are used. As used herein, the term "Group IIIB and / or Group IVB metal compound" refers to a compound comprising at least one element in Group IIIB or Group IVB of the Periodic Table of the CAS Elements.

In certain embodiments, the Group IIIB and / or Group IVB metal compounds used in the pretreatment composition are compounds of zirconium, titanium, hafnium, yttrium, cerium, or mixtures thereof. Suitable compounds of zirconium include but are not limited to hexafluorozirconic acid, alkali metal and ammonium salts thereof, ammonium zirconium carbonate, zirconyl nitrate, zirconium carboxylate and zirconium hydroxycarboxylate, such as hydrofluoro zirconic acid, zirconium Acetate, zirconium oxalate, ammonium zirconium glycolate, ammonium zirconium lactate, ammonium zirconium citrate, and mixtures thereof. Suitable compounds of titanium include, but are not limited to, fluorotitanic acid and its salts. Suitable compounds of hafnium include, but are not limited to, hafnium nitrate. Suitable compounds of yttrium include, but are not limited to, yttrium nitrate. Suitable compounds of cerium include, but are not limited to, cerium nitrate.

In certain embodiments, the Group IIIB and / or Group IVB metal compounds are present in the pretreatment composition in an amount of at least 10 ppm metal, such as at least 100 ppm metal, or in some cases at least 150 ppm metal. In certain embodiments, the Group IIIB and / or Group IVB metal compound is present in the pretreatment composition in an amount of up to 5000 ppm of metal, for example, up to 300 ppm of metal, or in some cases up to 250 ppm of metal . The amount of the Group IIIB and / or Group IVB metal in the pretreatment composition may range between any combination of the recited values, including the recited values. The pH of the pretreatment composition is often in the range of 2.0 to 7.0, such as 3.5 to 5.5. The pH of the pretreatment composition may be adjusted, for example, using any of the acids and bases indicated above with respect to the cleaning of the substrate previously.

In some embodiments, the pretreatment composition may be a pretreatment composition containing a silane or non-crystalline phosphate, such as iron phosphate. Suitable silane-containing pretreatment compositions include, but are not limited to, some commercially available products such as Silquest A-1100 silane, which is disclosed in embodiments of the present invention and is commercially available from Momentive Performance Materials ( Momentive Performance Materials). Suitable non-crystalline phosphate containing pretreatment compositions are described in, for example, U.S. Patent No. 5,294,265, Column 1, Line 53 to Column 3, Line 12 and U.S. Patent No. 5,306,526, Column 1, Line 46 to Column 3, Line 8 These pretreatment compositions include iron phosphate, manganese phosphate, calcium phosphate, magnesium phosphate, cobalt phosphate, or organic phosphate and / or organic phosphonate, as disclosed in the cited references. do. Suitable non-crystalline phosphate containing pretreatment compositions are commercially available, for example, the iron phosphate pretreatment compositions Chemfos 158 and Chemfos 51 are available from Phillips Industries, Inc. ≪ / RTI >

In certain embodiments, the pretreatment composition also comprises an electropositive metal, such as copper. The source of the electropositive metal, for example copper, in the pretreatment composition may comprise any of the materials previously described with respect to the plating solution, for example. In certain embodiments, the electropositive metal is included in an amount greater than or equal to 1 ppm, such as greater than or equal to 5 ppm, or, in some cases, greater than or equal to 10 ppm, of the total metal (measured as elemental metal) in the pretreatment composition as described above. In certain embodiments, the electropositive metal is included in the pretreatment composition as described above in an amount of less than 500 ppm, such as less than 100 ppm, or in some cases less than 50 ppm, of the total metal (measured as elemental metal).

In certain embodiments, the pretreatment composition comprises a resinous binder. Suitable resins include the reaction products of epoxy-functional materials containing at least one alkanolamine and at least two epoxy groups, such as those disclosed in U.S. Patent No. 5,653,823. In some cases, such a resin contains a beta hydroxy ester, imide, or sulfide functional group, and the functional group uses dimethylol propionic acid, phthalimide, or mercapto glycerine as an additional reactant in the preparation of the resin . On the one hand, the reaction product is a mixture of diglycidyl ether, dimethylol propionic acid, and diethanolamine of bisphenol A (commercially available as EPON 880 from Shell Chemical Company) 0.6 to 5.0: 0.05 to 5.5: 1. Other suitable resinous binders include water-soluble and water-dispersible polyacrylic acids such as those disclosed in U.S. Patent No. 3,912,548 and U.S. Patent No. 5,328,525; Phenol formaldehyde resins as disclosed in U.S. Patent No. 5,662,746; Water-soluble polyamides such as those disclosed in WO 95/33869; Copolymers of allyl ethers with maleic acid or acrylic acid as disclosed in Canadian Patent Application No. 2,087,352; And water-soluble and dispersible resins including epoxy resins, aminoplasts, phenol-formaldehyde resins, tannins, and polyvinylphenols as disclosed in U.S. Patent No. 5,449,415.

In these embodiments of the present invention, the resinous binder is present in the pretreatment composition in an amount of from 0.005% to 30% by weight, for example from 0.5 to 3% by weight, based on the total weight of the components in the composition.

However, in other embodiments, the pretreatment composition is substantially absent, or in some cases completely absent, any resinous bonding system. As used herein, the term " substantially free "when used in reference to the absence of a resinous binder in the pretreatment composition means that any resinous binder is present in the pretreatment composition in an amount of less than 0.005% by weight it means. As used herein, the term "completely absent" means that there is no resinous binder in the pretreatment composition.

The pretreatment composition may optionally contain other materials, such as non-ionic surfactants and adjuvants commonly used in the pretreatment arts. Among the aqueous medium, water-dispersible organic solvents such as alcohols having a carbon number of about 8 or less, such as methanol, isopropanol and the like; Or glycol ethers, such as ethylene glycol, diethylene glycol or monoalkyl ethers of propylene glycol, and the like. The water-dispersible organic solvent, if present, is typically used in an amount of about 10 volume percent or less based on the total volume of the aqueous medium.

Other optional materials include surfactants that act as antifoaming agents or substrate wetting agents, for example, the materials and amounts described above with respect to the plating solution.

In certain embodiments, the pretreatment composition comprises a reaction promoter such as a nitrite ion, a nitro-group containing compound, a hydroxylamine sulfate, a persulfate ion, a sulfite ion, a hyposulfite ion, As well as ascorbic acid, citric acid, tartaric acid, malonic acid, succinic acid, and salts thereof, as well as anions, anions, citrate compounds, bromate ions, perchlorinate ions, chlorate ions and chlorite ions. Specific examples of suitable materials and amounts thereof are disclosed in U.S. Patent Application Publication Nos. 2004/0163736 Al, [0032] to [0041], and the cited portions of the above publication are incorporated herein by reference.

In certain embodiments, the pretreatment composition also comprises a filler, such as a siliceous filler. Non-limiting examples of suitable fillers include silica, mica, montmorillonite, kaolinite, asbestos, talc, diatomaceous earth, vermiculite, natural and synthetic zeolites, cement, calcium silicate, aluminum silicate, sodium aluminum silicate, aluminum polysilicate, Glass particles. In addition to the siliceous filler, other finely divided particulate substantially water-insoluble fillers may also be used. Examples of such optional fillers include carbon black, charcoal, graphite, titanium oxide, iron oxide, copper oxide, zinc oxide, antimony oxide, zirconia, magnesia, alumina, molybdenum disulfide, zinc sulfide, barium sulfate, strontium Sulfate, calcium carbonate, and magnesium carbonate.

As shown, in certain embodiments, the pretreatment composition is substantially free of, or in some cases completely free of, chromate and / or heavy metal phosphate. As used herein, the term " substantially free "when used in reference to the absence of chromates and / or heavy metal phosphates in the pretreatment composition, for example zinc phosphate, But does not exist to such an extent. That is, the materials are not substantially used and the formation of sludge, such as zinc phosphate, formed when a treating agent based on zinc phosphate is used is excluded.

Moreover, in certain embodiments, the pretreatment composition is substantially free of, or in some cases completely free of, any organic material. As used herein, the term " substantially free " means that any organic material, when used in reference to the absence of the organic material in the composition, is present in the composition, if any, as an incidental impurity. That is, the presence of any organic material does not affect the properties of the composition. As used herein, the term "completely absent " means that no organic material is present in the composition.

In certain embodiments, the film coverage of the residue of the pretreatment coating composition is generally in the range of 1 to 1000 milligrams / square meter (mg / m 2), such as 10 to 400 mg / m 2. Though the thickness of the pretreatment coating can vary, it is generally very thin, often less than 1 占 퐉 thick, in some cases the thickness is between 1 and 500 nm, and in other cases the thickness is between 10 and 300 Nm.

In another specific embodiment of the present invention, the pretreatment composition comprises (a) a rare earth metal; And (b) a zirconyl compound. The pretreatment composition is applied directly to the metal substrate (i.e., in a one-step pretreatment process) without prior application of an electropositive metal.

Often, the pretreatment composition comprises the carrier, often an aqueous medium, such that the composition is in the form of a solution or dispersion of a rare earth metal compound and / or other pretreatment composition components in the carrier. In such an embodiment, the solution or dispersion may be applied to the substrate by any of a variety of known techniques, such as submerging or immersion, spraying, intermittent spraying, submersion followed by submersion, submersion, brushing or roll- . ≪ / RTI > In certain embodiments, the solution or dispersion is present at a temperature in the range of 60 to 150 ° F (15 to 65 ° C) when applied to a metal substrate. The contact time is often 10 seconds to 5 minutes, for example 30 seconds to 2 minutes.

As defined by IUPAC and as used in the present invention, rare earth or rare earth metals are a collection of 17 chemical elements of the Periodic Table of the Elements, specifically 15 lanthanides (atomic numbers 57 to 71, 15 from rhenium to ruthenium Element) + scandium and yttrium. If applicable, the metal itself may be used. In certain embodiments, a rare-earth metal compound is used. As used herein, the term "rare-earth metal compound" refers to a compound comprising at least one element that is a rare earth element as defined above.

In certain embodiments, the rare earth metal compound used in the pretreatment composition is a compound of yttrium, cerium, praseodymium, or mixtures thereof. Exemplary compounds that may be used include praseodymium chloride, praseodymium nitrate, praseodymium sulfate, cerium chloride, cerium nitrate, cerium sulfate, yttrium chloride, yttrium nitrate, yttrium sulfate.

In certain embodiments, the rare earth metal compound is present in the pretreatment composition in an amount of at least 10 ppm metal, such as at least 100 ppm metal, or in some cases at least 150 ppm metal. In certain embodiments, the rare earth metal compound is present in the pretreatment composition in an amount of up to 5000 ppm of metal, for example, up to 300 ppm of metal, or in some cases up to 250 ppm of metal. The amount of rare earth metal in the pretreatment composition may range between any values of the recited values, including the recited values.

As indicated above, the pretreatment composition also comprises a zirconyl compound. Zirconyl compounds refer to zirconium compounds having an oxide or hydroxide group on the zirconium atom as defined herein.

In certain embodiments, the zirconyl compound in the pretreatment composition is zirconyl nitrate (ZrO (NO ₃ ) ₂ ), zirconyl acetate, zirconyl carbonate, zirconyl sulfate, or mixtures thereof.

In certain embodiments, the ratio of zirconium (from the zirconyl compound or compounds) to the rare-earth metal (from the rare-earth metal or rare-earth metal compound) is from 200/1 to 1/1. In another embodiment, the ratio is 100/1 to 2/1. In certain embodiments, the ratio is 20/1.

In certain embodiments, the pretreatment composition also comprises Group IIIB, IVB and / or VB metals. As used herein, the term "Group IIIB, IVB and / or VB metal" refers to a metal of the Periodic Table of the Elements of the Periodic Table of the Elements of the Periodic Table of the Elements of the Periodic Table of Elements IIIB or IVB or VB. ≪ / RTI > If applicable, the metal itself may be used. In certain embodiments, Group IIIB, Group IV and / or Group VB metal compounds are used. As used herein, the term "Group IIIB, Group IV and / or Group VB metal compound" means containing at least one element in Group IIIB or Group IVB or Group VB of the Periodic Table of the CAS Elements.

In certain embodiments, the Group IIIB or Group IVB or Group VB metal compounds used in the pretreatment composition are compounds of zirconium, titanium, hafnium, yttrium, cerium, praseodymium, or mixtures thereof. Suitable zirconium compounds include, but are not limited to, hexafluorozirconic acid, alkali metal and ammonium salts thereof, ammonium zirconium carbonate, zirconyl nitrate, zirconium carboxylate and zirconium hydroxycarboxylates such as hydrofluoro zirconic acid, zirconium Acetate, zirconium oxalate, ammonium zirconium glycolate, ammonium zirconium lactate, ammonium zirconium citrate, and mixtures thereof. Suitable compounds of titanium include, but are not limited to, fluorotitanic acid and its salts. Suitable compounds of hafnium include, but are not limited to, hafnium nitrate. Suitable compounds of yttrium include, but are not limited to, yttrium nitrate. Suitable compounds of cerium include, but are not limited to, cerium nitrate.

In certain embodiments, the Group IIIB or Group IVB or Group VB metal compound is present in the pretreatment composition in an amount of at least 10 ppm metal, such as at least 100 ppm metal, or in some cases at least 150 ppm metal. In certain embodiments, the Group IIIB or Group IVB or Group VB metal compound is present in the pretreatment composition in an amount of up to 5000 ppm of metal, such as up to 300 ppm of metal, or in some cases up to 250 ppm of metal do. The amount of the Group IIIB or Group IVB or Group VB metal in the pretreatment composition may range between any combination of the recited values, including the recited values.

In certain embodiments, the pretreatment composition also comprises an electropositive metal. As used herein, the term "electropositive metal " refers to a metal that is more electropositive than the metal substrate. This means that, for purposes of the present invention, the term " electropositive metal "includes metals that are less easily oxidized than the metal-based metal. As will be appreciated by those skilled in the art, the tendency of metals to be oxidized is referred to as oxidation potential, expressed in volts, and is measured for standard hydrogen electrodes (which are randomly assigned with an oxidation potential of zero). The oxidation potentials of the various elements are shown in the following table. An element is less easily oxidized than another element if the element has a voltage value E ^* that is greater than the element compared to the element in the table below.

Thus, it will be appreciated that, as will be apparent, the metal substrate may be coated with materials previously listed, such as cold rolled steel, hot rolled steel, zinc metal, zinc compound or zinc alloy coated steel, hot dip galvanized steel, Electro-positive metals suitable for deposition in accordance with the present invention include, but are not limited to, nickel, copper, silver, copper, aluminum, aluminum, , And gold as well as mixtures thereof.

In certain embodiments, the source of the electropositive metal in the pretreatment composition is a water soluble metal salt. In a specific embodiment of the present invention, the water-soluble metal salt is a water-soluble copper compound. Specific examples of water-soluble copper compounds suitable for use in the present invention include, but are not limited to, copper cyanide, copper potassium cyanide, copper sulfate, copper nitrate, copper pyrophosphate, copper thiocyanate, disodium copper ethylenediamine tetraacetate But are not limited to, copper sulfate, copper sulfate, copper sulfate, copper sulfate, tetra hydrate, copper bromide, copper oxide, copper hydroxide, copper chloride, copper fluoride, copper gluconate, copper citrate, copper lauroyl sarcosinate, Butyrate, copper lactate, copper oxalate, copper phthalate, copper tartrate, copper malate, copper succinate, copper malonate, copper maliate, copper benzoate, copper salicylate, copper aspartate, copper glutamate, Copper fumarate, Copper salts of carboxylic acid in the formic acid homologous group to decanoic acid as well as copper glycerophosphate, sodium copper chlorophyllin, copper fluorosilicate, copper fluoroborate and copper iodate, copper salts of polybasic acids in oxalic acid series to suberic acid , And copper salts of hydroxycarboxylic acids including glycolic, lactic, tartaric, malic and citric acid.

When a copper ion supplied from the above-mentioned water-soluble copper compound is precipitated as an impurity in the form of copper sulfate or copper oxide, a complexing agent which stabilizes the copper ion in the solution by suppressing the precipitation of the copper ion is added May be desirable.

In certain embodiments, the copper compound is added as a copper complex salt, such as K ₃ Cu (CN) ₄ or Cu-EDTA, and the salt may exist solely in the composition stably, It is also possible to form a copper complex which can stably exist in the composition by bonding the compound with the complexing agent. Examples thereof are copper cyanide complexes formed by a combination of CuCn and KCN or a combination of CuSCN and KSCN or KCN, and Cu-EDTA complex formed by a combination of CuSO ₄ and EDTA.2Na.

With respect to the complexing agent, a compound capable of forming a complex with the copper ion can be used; Examples thereof include inorganic compounds, such as cyanide compounds and thiocyanate compounds, and polycarboxylic acids, specific examples of which include ethylenediaminetetraacetic acid, salts of ethylenediaminetetraacetic acid, such as disodium hydrogen Ethylenediamine tetraacetate dihydrate, aminocarboxylic acids such as nitrilotriacetic acid and iminodiacetic acid, oxycarboxylic acids such as citric acid and tartaric acid, succinic acid, oxalic acid, ethylenediaminetetramethylenephosphonic acid, and glycine do.

In certain embodiments, the electropositive metal, e. G., Copper, is present in the pretreatment composition in an amount of at least 1 ppm, such as at least 5 ppm, or in some cases at least 10 ppm total metal (measured as elemental metal) . In certain embodiments, the electropositive metal is included in an amount of less than 500 ppm, such as less than 100 ppm, or in some cases less than 50 ppm, total metal (measured as elemental metal) in the pretreatment composition as described above . The amount of electropositive metal in the pretreatment composition may range between any combination of the recited values, including the recited values.

The pretreatment composition may optionally contain other materials, such as non-ionic surfactants and adjuvants commonly used in the pretreatment arts. Among aqueous media, water-dispersible organic solvents, such as alcohols having up to about 8 carbon atoms, such as methanol, isopropanol, etc., are present; Or glycol ethers, such as ethylene glycol, diethylene glycol, or monoalkyl ethers of propylene glycol, and the like. When present, the water-dispersible organic solvent is typically used in an amount of about 10 volume percent or less based on the total volume of the aqueous medium.

Other optional materials include surfactants that act as defoamers or substrate wetting agents, such as the materials and amounts disclosed above with respect to the plating solution.

In certain embodiments, the pretreatment composition also comprises a reaction promoter such as a nitrite ion, a nitro-group containing compound, a hydroxyamine sulfate, a persulfate ion, a sulfite ion, a hypofusite ion, a peroxide, Citric acid, tartaric acid, malonic acid, succinic acid, and salts thereof, as well as chloride ions, chloride ions, chloride ions, chloride ions, chloride ions, Specific examples of suitable materials and amounts thereof are disclosed in U.S. Patent Application Publication Nos. 2004/0163736 Al, [0032] to [0041], the cited portions of which are incorporated herein by reference.

In certain embodiments, the pretreatment composition also comprises a filler, such as a siliceous filler. Non-limiting examples of suitable fillers include silica, mica, montmorillonite, kaolinite, asbestos, talc, diatomaceous earth, vermiculite, natural and synthetic zeolites, cement, calcium silicate, aluminum silicate, sodium aluminum silicate, aluminum polysilicate, Particles. In addition to the siliceous filler, other finely divided particulate substantially water-insoluble fillers may also be used. Examples of such optional fillers include carbon black, charcoal, graphite, titanium oxide, iron oxide, copper oxide, zinc oxide, antimony oxide, zirconia, magnesia, alumina, molybdenum disulfide, zinc sulfide, barium sulfate, strontium Sulfate, calcium carbonate, and magnesium carbonate.

As shown, in certain embodiments, the pretreatment composition is substantially free of, or in some cases completely free of, chromate and / or heavy metal phosphate. As used herein, the term " substantially free "when used in connection with the absence of chromates and / or heavy metal phosphates, such as zinc phosphate, in the pretreatment composition, To the extent that it does not exist. That is, the formation of sludge formed, for example, zinc phosphate, is excluded when the materials are not substantially used and zinc phosphate based treatments are used.

Moreover, in certain embodiments, the pretreatment composition is substantially free of, or in some cases completely free of, any organic material. As used herein, the term " substantially free " means that any organic material, when used in reference to the absence of the organic material in the composition, is present in the composition, if any, as an incidental impurity. That is, the presence of any organic material does not affect the properties of the composition. As used herein, the term "completely absent " means that no organic material is present in the composition.

In certain embodiments, the film coverage of the residue of the pretreatment coating composition is generally in the range of 1 to 1000 milligrams / square meter (mg / m 2), such as 10 to 400 mg / m 2. The thickness of the pretreatment coating may vary, but is generally very thin, often less than 1 μm in thickness, in some cases the thickness is between 1 and 500 nm, and in other cases the thickness is between 10 and 300 nm .

Following contact with the pretreatment solution according to any of the above embodiments, the substrate may be washed with water and dried.

Additional coating compositions after pretreatment

In certain embodiments of the process of the present invention, the substrate is contacted with the acid and optionally an alkaline detergent and optionally a pretreatment composition, followed by a coating composition comprising a film-forming resin. The substrate may be contacted with such a coating composition using any suitable technique, such as brushing, dipping, flow coating, spraying, and the like. However, in certain embodiments, as described in more detail below, such contact includes an electrocoating step of depositing the electrodepositable composition on the metal substrate by electrodeposition.

As used herein, the term "film-forming resin" refers to a resin that forms a self-sustaining continuous film upon removal of any diluent or carrier present in the composition, or at least upon curing at ambient or elevated temperatures, Refers to a resin that can be used. Typical film-forming resins that may be used are, among others, those typically used in automotive OEM coating compositions, automotive retread coating compositions, industrial coating compositions, architectural coating compositions, coil coating compositions, and aerospace coating compositions .

In certain embodiments, the coating composition comprises a thermosetting film-forming resin. As used herein, the term "thermoset" refers to a resin that is "cured" irreversibly upon curing or crosslinking, wherein the polymer chains of the polymer components are bonded together by covalent bonds. This property is usually associated with cross-linking reactions of the components of the composition, which are often caused, for example, by heat or irradiation. The curing or crosslinking reaction may also be carried out under ambient conditions. Once cured or crosslinked, the thermosetting resin will not melt upon application of heat and is insoluble in the solvent. In another embodiment, the coating composition comprises a thermoplastic film-forming resin. As used herein, the term "thermoplastic" refers to a resin that is not bonded by a covalent bond and thereby experiences polymeric components that are capable of undergoing liquid flow upon heating and which are soluble in the solvent.

As indicated above, in certain embodiments, the substrate is contacted with a coating composition comprising a film-forming resin by an electrocoating step wherein the electrodepositable composition is deposited on the metal substrate by electrodeposition. In the electrodeposition process, the metal substrate to be treated, which acts as an electrode, and the electroconductive counter electrode are placed in contact with the ionic, electrodepositable composition. Upon passage of an electric current therebetween while the electrode and the counter electrode remain in contact with the electrodepositable composition, the adherent film of the electrodepositable composition will be deposited on the metallic substrate in a substantially continuous manner.

Electrodeposition is usually carried out at a constant voltage ranging from 1 volt to several thousand volts, typically in the range of 50 to 500 volts. The current density is usually from 1.0 amperes to 15 amps / sq. Ft. (10.8 to 161.5 amperes per square meter) and tends to decrease rapidly during the electrodeposition process, indicating the formation of a continuous self-insulating film.

The electrodepositable composition used in certain embodiments of the present invention comprises a resinous phase, often dispersed in an aqueous medium, wherein the dendritic resin comprises (a) an active hydrogen group-containing ionic electrodepositable resin, and (b) ) ≪ / RTI > of the active hydrogen group.

In certain embodiments, the electrodepositable compositions used in certain embodiments of the present invention are primary film-forming polymers and contain active hydrogen-containing ionic, often cationic electrodepositable resins. A wide variety of electrodepositable film-forming resins are known and may be used in the present invention as long as the polymers are "water dispersible ", i.e., soluble in water, dispersed or emulsified. The water-dispersible polymer is substantially ionic, i.e. the polymer will contain anionic functional groups to impart a negative charge, or often will preferably contain cationic functional groups to impart a positive charge.

Examples of film-forming resins suitable for use in anionic electrodepositable compositions include, but are not limited to, reaction products or adducts of base-dissolved, carboxylic acid containing polymers such as dry oil or semi-dry fatty acid esters with dicarboxylic acids or anhydrides; And reaction products of fatty acid esters, unsaturated acids or anhydrides with any further unsaturated modified materials (further reacted with polyols). Also suitable are at least partially neutralized copolymers of hydroxy-alkyl esters of unsaturated carboxylic acids, unsaturated carboxylic acids and one or more other ethylenically unsaturated monomers. Yet another suitable electrodepositable film-forming resin comprises an alkyd-aminoplast vehicle, i.e., a vehicle containing an alkyd resin and an amine-aldehyde resin. Still another anionic electrodepositable resin composition comprises a mixed ester of a resinous polyol, for example an ester as disclosed in U.S. Patent No. 3,749,657, column 9, lines 1 to 75 and column 10, lines 1 to 13 , The above-cited portions being incorporated herein by reference. Other acid functional polymers, such as phosphated polyepoxide or phosphated acrylic polymers, as is known to those skilled in the art can also be used.

As mentioned above, it is often desirable that the active hydrogen-containing ionic electrodepositable resin (a) is cationic and capable of being deposited on a cathode. Examples of such cationic film-forming resins are acid-soluble reaction products of amine salt group-containing resins, such as polyepoxides and primary or secondary amines, such as those described in U.S. Patent No. 3,663,389; U.S. Patent No. 3,984,299; U.S. Patent No. 3,947,338; And U.S. Patent No. 3,947,339. Often, these amine salt group-containing resins are used with blocked isocyanate curing agents. The isocyanate may be completely blocked as disclosed in U.S. Patent No. 3,984,299, or the isocyanate may be partially blocked and reacted with the resin backbone as disclosed in U.S. Patent No. 3,947,338. Also, one-component compositions as disclosed in U.S. Pat. No. 4,134,866 and DE-OS No. 2,707,405 can be used as film-forming resins. In addition to the epoxy-amine reaction products, film-forming resins may also be selected from cationic acrylic resins, such as those disclosed in U.S. Patent Nos. 3,455,806 and 3,928,157.

In addition to the amine salt group-containing resin, quaternary ammonium salt group-containing resins such as U.S. Patent No. 3,962,165; 3,975,346; And the tertiary amine salts as disclosed in U.S. Patent No. 4,001,101 can also be used. Examples of other cationic resins are tertiary sulfonium salt group-containing resins and quaternary phosphonium salt group-containing resins, such as those disclosed in, for example, U.S. Patent No. 3,793,278 and U.S. Patent No. 3,984,922. In addition, film-forming resins that cure through transesterification, such as those disclosed in European Application No. 12463, can be used. Furthermore, cationic compositions prepared from Mannich bases, such as those disclosed in U.S. Patent No. 4,134,932, can be used.

In certain embodiments, the resin present in the electrodepositable composition is a positively charged resin containing primary and / or secondary amine groups, for example, U.S. Patents 3,663,389; U.S. Patent No. 3,947,339; And U.S. Patent No. 4,116,900. In U.S. Patent No. 3,947,339, polyamines, such as diethylene triamine or polyketamines derivatives of triethylenetetramine, are reacted with the polyepoxide. When the reaction product is neutralized with an acid and dispersed in water, a free primary amine group is generated. Also, as disclosed in U.S. Patent No. 3,663,389 and U.S. Patent No. 4,116,900, polyepoxides are reacted with excess polyamines such as diethylenetriamine and triethylenetetramine, and excess polyamines Is vacuum stripped, an equivalent product is formed.

In a specific embodiment, the active hydrogen-containing ionic electrodepositable resin is present in the electrodepositable composition in an amount of 1 to 60% by weight, for example 5 to 25% by weight, based on the total weight of the electrodeposition bath .

As shown, the resinous phase of the electrodepositable composition further comprises a curing agent which is often suitable to react with the active hydrogen groups of the ionic electrodepositable resin. For example, both blocked organic polyisocyanates and aminoplast curing agents are suitable for use in the present invention, but blocked isocyanates are often preferred for cathode electrodeposition.

Aminoplast resins, which are often preferred curing agents for anionic deposition, are condensation products of amines or amides with aldehydes. Examples of suitable amines or amides are melamine, benzoguanamine, urea and similar compounds. Generally, the aldehyde used can be prepared from formaldehyde, or from other aldehydes such as acetaldehyde and furfural. The condensation product contains a methylol group or similar alkylol group depending on the particular aldehyde used. Often these methylol groups are etherified by reaction with alcohols, e. G., Monohydric alcohols of 1 to 4 carbon atoms, such as methanol, ethanol, isopropanol and n-butanol. Aminoplast resins are commercially available from American Cyanamid Co. under the trade designation CYMEL and from Monsanto Chemical Co. under the trade designation RESIMENE .

The aminoplast hardener is often used together with the active hydrogen-containing anionic electrodepositable resin in an amount of from 5 to 60% by weight, for example from 20 to 40% by weight, based on the total weight of the resin solids in the electrodepositable composition Used in quantities.

As shown, the blocked organic polyisocyanate is often used as a curing agent in a cathode electrodeposition composition. The polyisocyanate may be completely blocked as disclosed in U.S. Patent No. 3,984,299, column 1, lines 1-68, column 2 and column 3, lines 1 to 15, or alternatively, as disclosed in U.S. Patent No. 3,947,338, column 2, lines 65-68 , Column 3 and Column 4, lines 1-30, and reacted with the polymer backbone, the above-referenced portions being incorporated herein by reference. "Blocked" means that the isocyanate group has reacted with the compound such that the resulting blocked isocyanate group is stable to active hydrogen at ambient temperature, but is usually reactive with active hydrogens in the film forming polymer at an elevated temperature of 90 ° C to 200 ° C it means.

Suitable polyisocyanates include aromatic and aliphatic polyisocyanates including alicyclic polyisocyanates, representative examples being diphenylmethane-4,4'-diisocyanate (MDI), 2,4- or 2,6-toluene diisocyanate (TDI) (including mixtures thereof), p-phenylene diisocyanate, tetramethylene and hexamethylene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, isophorone diisocyanate, phenylmethane- 4'-diisocyanate and a mixture of polymethylene polyphenyl isocyanate. More advanced polyisocyanates, such as triisocyanates, can be used. Examples will include triphenylmethane-4,4 ', 4 "-triisocyanate. Polyols such as neopentyl glycol and trimethylol propane, and polymeric polyols such as polycaprolactone diol and An isocyanate () - prepolymer with a triol (greater than 1 NCO / OH equivalent ratio) can also be used.

The polyisocyanate curing agent is typically added to the active hydrogen-containing cationic electrodepositable resin in an amount ranging from 5 to 60% by weight, for example, from 20 to 50% by weight, based on the total weight of the resin solids in the electrodepositable composition .

In certain embodiments, the coating composition comprising the film-forming resin also comprises yttrium. In certain embodiments, yttrium is present in an amount of from 10 to 10,000 ppm, such as less than 5,000 ppm, and in some cases less than 1,000 ppm, of total yttrium (measured as elemental yttrium) in such compositions.

Both soluble and insoluble yttrium compounds can act as a source of yttrium. Examples of yttrium sources suitable for use in lead-free electrodepositable coating compositions are soluble organic and inorganic yttrium salts such as yttrium acetate, yttrium chloride, yttrium carbonate, yttrium sulfamate, yttrium lactate, and yttrium nitrate . When yttrium is to be added as an aqueous solution to an electrocoating bath, yttrium nitrate, a readily available yttrium compound, is the preferred yttrium source. Other yttrium compounds suitable for use in electrodepositable compositions are organic and inorganic yttrium compounds, such as yttrium oxide, yttrium bromide, yttrium hydroxide, yttrium molybdate, yttrium sulfate, yttrium silicate, and yttrium oxalate. Organic yttrium complexes and yttrium metals may also be used. When yttrium is to be incorporated into the electrocoating bath as a component in the pigment paste, yttrium oxide is often the preferred source of yttrium.

The electrodepositable composition disclosed in the present invention is in the form of an aqueous dispersion. The term "dispersion" is considered to be a two-phase transparent, translucent or opaque resinous system in which the resin is in a dispersed phase and water is in a continuous phase. The average particle size of the resin is generally less than 1.0 and usually less than 0.5 mu m, often less than 0.15 mu m.

The concentration of the dendritic phase in the aqueous medium is often at least 1% by weight, for example from 2 to 60% by weight, based on the total weight of the aqueous dispersion. When such a composition is in the form of a resin concentrate, the composition generally has a resin solids content of from 20 to 60% by weight, based on the weight of the aqueous dispersion.

The electrodepositable compositions disclosed in the present invention are often supplied as two components: (1) generally an active hydrogen-containing ionic electrodepositable resin, i.e., a main film-forming polymer, a curing agent, and any additional water- A clear resin feed comprising the components; And (2) a pigment paste, generally comprising one or more coloring agents (described below), a water dispersible milling resin which may be the same as or different from the main-film forming polymer, and optionally additives such as wetting or dispersing assistants. The electrodeposition bath components (1) and (2) are dispersed in an aqueous medium comprising water, and usually a coalescing solvent.

As mentioned above, the aqueous medium may contain, in addition to water, a fusing solvent. Useful fusion solvents are often hydrocarbons, alcohols, esters, ethers, and ketones. Preferred fusion solvents are often alcohols, polyols and ketones. Specific fusing solvents include isopropanol, butanol, 2-ethylhexanol, isophorone, 2-methoxypentanone, ethylene and propylene glycol, and monoethyl monobutyl and monohexyl ether of ethylene glycol. The amount of the fusion solvent is generally from 0.01 to 25% by weight, for example from 0.05 to 5% by weight, based on the total weight of the aqueous medium.

In addition, colorants and, if desired, various additives such as surfactants, wetting agents or catalysts may be included in the coating composition comprising the film-forming resin. As used herein, the term "colorant" refers to any material that imparts color and / or other opacity and / or other visual effects to the composition. The colorant may be added to the composition in any suitable form, for example in the form of discrete particles, dispersions, solutions and / or flakes. A single colorant or a mixture of two or more colorants may be used.

Exemplary colorants include pigments, dyes and tinting agents, such as those used in the paint industry and / or those listed in the Dry Color Manufacturers Association (DCMA) as well as special effect compositions. The colorant includes, for example, fine powdery solids which are insoluble or wettable under the conditions of use. The colorant may be organic or inorganic and may not aggregate or aggregate. The colorant may be included by the use of a grinding vehicle, such as an acrylic grinding vehicle, and the use of such a vehicle will be familiar to those skilled in the art.

Exemplary pigment and / or pigment compositions include, but are not limited to, carbazole dioxazine pigments, azo, monoazo, disazo, naphthol AS, salt type (lake), benzimidazolone, condensation, metal complexes, isoindolinone , Isoindoline and polycyclic phthalocyanine, quinacridone, perylene, perrinone, diketopyrrolopyrrole, thioindigo, anthraquinone, indanthrone, anthrapyrimidine, flavanthrone, pyranthrone, anthanthrone, Quinophthalone pigments, diketopyrrolopyrrole red ("DPPBO red"), titanium dioxide, carbon black, and mixtures thereof. The terms "pigment" and "colored filler" may be used interchangeably.

Exemplary dyes include, but are not limited to, those which are solvent and / or aqueous based, such as phthalogreen or blue, iron oxide, bismuth vanadate, anthraquinone, perylene, aluminum and quinacridone.

Exemplary tinting agents include, but are not limited to, pigments dispersed in an aqueous or water-miscible carrier such as AQUA-CHEM 896 commercially available from Degussa, Inc., And CHARISMA COLORANTS and MAXITONER INDUSTRIAL COLORANTS, which are commercially available from a precision dispersion of Eastman Chemical, Inc.

As indicated above, the colorant may be present in the form of a dispersion, including, but not limited to, nanoparticle dispersions. The nanoparticle dispersion may comprise one or more highly dispersed nanoparticle coloring and / or colorant particles that produce the desired visible color and / or opacity and / or visual effects. The nanoparticle dispersion may comprise a colorant, such as a pigment or dye, having a particle size of less than 150 nm, for example less than 70 nm, or less than 30 nm. Nanoparticles can be produced by milling an organic or inorganic pigment stock with a milling medium having a particle size of less than 0.5 mm. Exemplary nanoparticle dispersions and methods for their preparation are identified in U.S. Patent No. 6,875,800 B2, which is incorporated herein by reference. Nanoparticle dispersions can also be produced by crystallization, precipitation, gas phase condensation, and chemical abrasion (i.e., partial dissolution). To minimize re-aggregation of the nanoparticles in the coating, a dispersion of resin-coated nanoparticles may be used. As used herein, "dispersion of resin-coated nanoparticles" refers to a continuous phase in which discrete "composite microparticles" containing nanoparticles and resin coatings on the nanoparticles are dispersed. Exemplary resin-coated nanoparticle dispersions and methods for their preparation are described in U.S. Patent Application Publication No. 2005-0287348 A1, filed June 24, 2004, U.S. Provisional Application No. 60 / And U.S. Patent Application No. 11 / 337,062, filed January 20, 2006, which is also incorporated herein by reference.

Exemplary special effect compositions that can be used are those that exhibit one or more cosmetic effects such as, for example, reflectance, pearlescent, metallic luster, phosphorescence, fluorescence, photochromic phenomena, photosensitivity, heat discoloration phenomena, goniocromics and / And / or < / RTI > Additional special effect compositions may provide other perceptible properties, opacity, or texture. In certain embodiments, the special effect composition can create a color shift such that the color of the coating changes when the coating is viewed at different angles. Exemplary color effect compositions are identified in U.S. Patent No. 6,894,086, which is incorporated herein by reference. The additional color effect composition may comprise transparent coated mica and / or synthetic mica, coated silica, coated alumina, transparent liquid crystal pigment, liquid crystal coating, and / or any composition wherein the interference is caused by a refractive index difference But is not produced due to the refractive index difference between the surface of the substance and air.

In certain embodiments, the photosensitive composition and / or photochromic composition (its color reversibly changes upon exposure to one or more light sources) can be used. The photochromic and / or photosensitive composition may be activated by exposure to a particular wavelength of irradiation. When the composition is excited, the molecular structure changes and the modified structure exhibits a new color that is different from the original color of the composition. When the exposure to the radiation is removed, the photochromic and / or photosensitive composition can be restored to its resting state, where the original color of the composition is restored. In certain embodiments, the photochromic and / or photosensitive composition can be achromatic in its unexcited state and can exhibit color in an excited state. A full color-change can occur within a few seconds to a few minutes, for example between 20 seconds and 60 seconds. Exemplary photochromic and / or photosensitive compositions include photochromic dyes.

In certain embodiments, the photosensitive composition and / or photochromic composition may be associated and / or at least partially bound to the polymeric and / or polymeric material of the polymerizable component by, for example, covalent bonding. A photosensitive composition associated with and / or at least partially bound to the polymer and / or the polymerizable component in accordance with certain embodiments of the present invention, and a photosensitive composition that is associated with the polymer and / or polymeric component in accordance with certain embodiments of the present invention, as opposed to some coatings capable of moving the photosensitive composition out of the coating, / RTI > and / or photochromic composition migrates to a minimum outside the coating. Exemplary photosensitive and / or photochromic compositions and methods of making the same are identified in U.S. Patent Application No. 10 / 892,919, filed July 16, 2004, which is incorporated herein by reference.

In general, the colorant may be present in any amount sufficient to impart the desired visual and / or color effect to the coating composition. The colorant may comprise from 1 to 65% by weight, for example from 3 to 40% by weight or from 5 to 35% by weight, based on the total weight of the composition.

After deposition, the coating is often heated to cure the deposited composition. The heating or curing process is often carried out at a temperature ranging from 120 to 250 ° C, for example from 120 to 190 ° C, for a period ranging from 10 to 60 minutes. In certain embodiments, the thickness of the resulting film is from 10 to 50 mu m.

The electrodepositable coating composition in the absence of pretreatment

In certain embodiments of the process of the present invention, the substrate can be contacted with an electrodepositable coating composition comprising (i) a film-forming compound and (ii) a source of yttrium, without subsequent contact with the pretreatment composition after contact with the acid have.

As defined herein, the term "without subsequent contact with a pretreatment composition" means that the substrate is allowed to react with the substrate surface upon contact with the substrate, chemically altering the substrate surface and bonding Layer is not contacted with the composition forming the layer. The pretreatment composition comprises any of the pretreatment compositions comprising a Group IIIB and / or Group IVB metal as specifically described above, and may include other known pretreatment agents such as, for example, zinc or iron phosphate-type conversion or pretreatment coatings Further comprising a composition.

In certain embodiments, the electrodepositable coating composition can be formed according to U.S. Patent Application No. 12 / 693,626, which is incorporated herein by reference, which composition comprises (iii) a silane that does not contain an ethylenically unsaturated double bond, May also be included. In certain embodiments, the coating composition may be formed according to U.S. Patent Application No. 12 / 693,626, and may further comprise (iii) an aminosilane that may or may not contain an ethylenically unsaturated double bond have.

In some embodiments, when the film-forming polymer comprises a reactive functional group, the coating composition further comprises (iv) a curing agent that is reactive with the reactive functional groups of the film-forming polymer.

A wide variety of film-forming polymers known in the art can be used as component (i) so long as the polymer is "water dispersible ". As used herein, "water-dispersible" means suitable for dissolving, dispersing and / or emulsifying a material in water. The film-forming polymers used in the present invention are substantially ionic. Thus, in some embodiments, the film-forming polymer is cationic. That is, the film-forming polymer comprises a cationic salt group that is generally prepared by neutralizing functional groups on the film-forming polymer with an acid, which can cause the film-forming polymer to be electrodeposited on the cathode.

Examples of film-forming polymers suitable for use in cationic electrocoat coating compositions include, but are not limited to, cationic polymers derived from polyepoxides, acrylics, polyurethanes and / or polyesters. In certain embodiments, the film-forming polymer comprises a reactive functional group. As used herein, the term "reactive functional group" means hydroxyl, carboxyl, carbamate, epoxy, isocyanate, acetoacetate, amine-salt, mercaptan or combinations thereof. In some embodiments, it should be noted that the film-forming polymer is a copolymer of the polymers listed in the preceding sentence. In some embodiments, the cationic polymer can be derived by reacting the polyepoxide containing polymer with a cationic salt forming agent. As used herein, the term "cationic salt forming agent" means a material that is reactive with an epoxy group and is capable of forming a cationic salt group before, during, or after the reaction with the epoxy group. Suitable materials which can be used as cationic salt formers include amines, such as primary or secondary amines that can be acidified after reaction with the epoxy groups to form amine salt groups, or acidified prior to reaction with the epoxy groups, And tertiary amines capable of forming quaternary ammonium salt groups after the reaction. Examples of other cationic salt group forming agents are sulfides, which may be mixed with an acid before the reaction with the epoxy group to form a tertiary sulfonium salt group in the subsequent reaction with the epoxy group.

In certain embodiments, the film-forming polymer (i) used in the present invention is an epoxy functional compound (such as iphone 880) and a phenolic hydroxyl group-containing material, such as bisphenol A (which is a polyhydric phenol) ≪ / RTI > In some embodiments, in order to render the film-forming polymer (i) disclosed in the preceding sentence water-dispersible, the polymer may be reacted with an amine such as aminopropyl diethanolamine (APDEA) and dimethylaminopropylamine have. In certain embodiments, the ketimine can be reacted with the main chain of the film-forming polymer, thereby forming a ketimine branch extending to the pendant in the main chain. When the polymer is dispersed in a water / acid mixture, the ketimine moiety will hydrolyze to form a primary amine. Thus, in some embodiments, the electrodepositable coating compositions disclosed in U.S. Pat. No. 5,633,297, U.S. Pat. No. 5,820,987 and / or U.S. Pat. No. 5,936,012 may be used in the present invention.

A variety of corrosion inhibitors may be used as component (a) in the present invention. Suitable corrosion inhibitors include, but are not limited to, rare earth metals, bismuth, copper, zinc, silver, zirconium or combinations thereof. In certain embodiments, yttrium compounds or cerium compounds, or mixtures of yttrium and cerium compounds, can be used as corrosion inhibitors. The yttrium and cerium compounds, as defined in the present invention, include their respective salts, which may hereinafter simply be referred to as yttrium compounds or cerium compounds in the present invention. They may also be included in the list of possible compounds including the source of yttrium or the source of cerium.

A variety of yttrium compounds may be used as component (ii) in the present invention. For example, the yttrium compounds may include, but are not limited to, yttrium formate, yttrium acetate, yttrium lactate, yttrium sulfamate, yttrium methanesulfonate, yttrium nitrate, or combinations thereof. In some embodiments, yttrium accounts for ≤5 wt% of the total resin solids of the electrodepositable coating composition. In another embodiment, yttrium accounts for ≥ 0.15% by weight of the total resin solids of the electrodepositable coating composition. In certain embodiments, the amount of yttrium may range between any combination of these values, including the values quoted in the preceding sentence. For example, in certain embodiments, the amount of yttrium may range from 0.20% to 2% by weight of the total resin solids of the electrodepositable coating composition.

A variety of cerium compounds can be used as component (ii) in the present invention. For example, the cerium compound is selected from the group consisting of ammonium cerium nitrate, ammonium cerium sulfate, cerium acetate, cerium bromide, cerium carbonate, cerium chloride, cerium fluoride, cerium iodide, cerium nitrate, cerium molybdate, Cerium oxalate, cerium phosphate, and cerium sulfate. In some embodiments, cerium accounts for ≤5 wt% of the total resin solids of the electrodepositable coating composition. In another embodiment, cerium accounts for ≥ 0.15% by weight of the total resin solids of the electrodepositable coating composition. In certain embodiments, the amount of cerium may range between any combination of these values, including the values quoted in the preceding sentence. For example, in certain embodiments, the amount of cerium may range from 0.20% to 2% by weight of the total resin solids of the electrodepositable coating composition.

Various combinations of yttrium and cerium compounds as described in the preceding paragraphs can be used as component (ii) in the present invention. In some embodiments, the combination of yttrium and cerium accounts for less than 5% by weight of the total resin solids of the electrodepositable coating composition. In another embodiment, the combination of yttrium and cerium accounts for ≥ 0.15% by weight of the total resin solids of the electrodepositable coating composition. In certain embodiments, the amounts of yttrium and cerium may range between any combination of these values, including the values quoted in the preceding sentence. For example, in certain embodiments, the amount of yttrium and cerium may range from 0.20% to 2% by weight of the total resin solids of the electrodepositable coating composition.

(i) the electrodepositable coating composition further comprises (iv) a crosslinking agent ("hardener") that is reactive with the reactive functional groups of the polymer when the film-forming polymer comprises reactive functional groups such as those described above can do. Suitable crosslinking agents include, but are not limited to, aminoplasts, polyisocyanates (including blocked isocyanates), polyepoxides, beta-hydroxyalkyl amides, polyacids, anhydrides, organometallic acid-functional materials, polyamines, polyamides , Cyclic carbonates, siloxanes, or combinations thereof. In some embodiments, the curing agent may comprise from 30% to 40% by weight of the total resin solids of the coating composition.

In certain embodiments, the electrodepositable coating composition may further comprise (c) a curing catalyst that can be used to catalyze the reaction of the crosslinking agent with the reactive functional duration of the film-forming polymer. Suitable curing catalysts which can be used as component (v) include, but are not limited to, organotin compounds (e.g., dibutyltin oxide, dioctyltin oxide) and salts thereof (e.g., dibutyltin diacetate); (For example, oxides of cerium, zirconium and / or bismuth) and salts thereof (for example, bismuth sulfamate and / or bismuth lactate), bicyclic guanidine (disclosed in U.S. Patent Application No. 11 / 835,600 Or a combination thereof).

The electrodepositable coating compositions disclosed herein are typically supplied as two components, namely (1) a main vehicle ("transparent resin feed") and (2) a pulverizing vehicle ("pigment paste"). In general, (1) the main vehicle is a film-forming polymer ("active hydrogen-containing ionic salt group-containing resin"), (b) a crosslinking agent, and (c) any additional water- Coloring components (e.g., catalysts, hindered amine light stabilizers). Generally, (2) the pulverizing vehicle comprises (d) one or more pigments (e. G., Titanium dioxide, carbon black), (e) a water dispersible milling resin which may be the same as or different from the film- ) Additives, such as catalysts, antioxidants, biocides, defoamers, surfactants, wetting agents, dispersants, clays, hindered amine light stabilizers, UV light absorbers and stabilizers, or combinations thereof. An electrodeposition bath containing the electrodepositable coating composition of the present invention can be prepared by dispersing components (1) and (2) in an aqueous medium comprising water and usually a fusing solvent. (Ii) the yttrium and / or (iii) silane used in the electrodepositable coating composition of the present invention may be incorporated into a primary vehicle, a grinding vehicle, or after the post-treatment of the bath with the components (1) and (2) May be added. On the one hand, components (1) and (2) may also be provided as a single component.

The electrodepositable coating compositions disclosed herein can be applied alone or as part of a coating system that can be deposited onto a number of different substrates. The coating system typically comprises a plurality of coaching layers. The coating layer is typically formed when the coating composition deposited on the substrate is substantially cured by methods known in the art (e.g., by thermal heating).

After curing the electrodepositable coating composition, a primer-surfacer coating composition is applied over at least a portion of the electrodepositable coating composition. The primer-spacer coating composition is typically applied to the electrodepositable coating layer and the subsequent coating composition is cured prior to application onto the primer-surface coating composition.

The primer-spacer layer produced from the primer-spacer coating composition not only enhances endurance of the coating system but also increases the appearance of subsequently applied layers (e.g., a color-imparting coating composition and / or a substantially transparent coating composition) It works to help. As used herein, the term "primer-spacer" refers to a primer composition for use under the coating composition that is subsequently applied, and includes thermoplastic and / or crosslinkable materials commonly known in the art of organic coating compositions Thermosetting) film-forming resin. Suitable primer and primer-spacer coating compositions include spray applied primers as are known to those skilled in the art. Examples of suitable primers include DPX-1791, DPX-1804, DSPX-1537, GPXH-5379, OPP-2645, PCV-70118, and 1177-225A from Pfizer Incorporates of Pittsburgh, Pennsylvania Which is available as < / RTI > Another suitable primer-spacer coating composition that may be used in the present invention is the primer-spacer disclosed in U.S. Patent Application No. 11 / 773,482, which is incorporated herein by reference in its entirety.

It should be noted that in some embodiments, the primer-surface coating composition is not used in the coating system. Thus, a color imparting base coat coating composition can be applied directly onto the cured electrodepositable coating composition.

In some embodiments, a color imparting coating composition (hereinafter "a basecoat" in the present invention) is deposited over at least a portion of the primer surfacer coating layer (if present). Any base coat coating composition known in the art can be used in the present invention. It should be noted that these base coat coating compositions typically include colorants.

In certain embodiments, a substantially transparent coating composition (hereinafter "clear coat" in the present invention) is deposited over at least a portion of the base coat coating layer. As used herein, a "substantially transparent" coating layer is substantially transparent and not opaque. In certain embodiments, the substantially transparent coating composition may include a colorant, but does not include the clear coating composition in an amount that is opaque (substantially not transparent) after curing. Any clearcoat coating composition known in the art can be used in the present invention. For example, the clearcoat coating compositions disclosed in U.S. Patent No. 5,989,642, U.S. Patent No. 6,245,855, U.S. Patent No. 6,387,519, and U.S. Patent No. 7,005,472, all of which are incorporated herein by reference, have. In certain embodiments, the substantially transparent coating composition may also comprise particles, such as silica particles, dispersed in the clearcoat coating composition (e.g., on the surface of the clearcoat coating composition after curing).

One or more of the coating compositions disclosed herein may comprise a colorant and / or any other materials, which are known in the formulated surface coatings art. As used herein, the term "colorant" refers to any material that imparts color and / or other opacity and / or other visible effects to the composition. The colorant may be added to the coating in any suitable form, for example in the form of discrete particles, dispersions, solutions and / or flakes (for example aluminum flakes). A single colorant or a mixture of two or more colorants may be used in the coating compositions disclosed herein.

Exemplary colorants include pigments, dyes and tinting agents, such as those that are used in the paint industry and / or listed in the Dry Color Manufacturers Association (DCMA) as well as special effect compositions. The colorant includes, for example, fine powdery solids which are insoluble or wettable under the conditions of use. The colorant may be organic or inorganic and may not aggregate or aggregate. The colorant may be included by the use of a grinding vehicle, such as an acrylic grinding vehicle, and the use of such a vehicle will be familiar to those skilled in the art.

Exemplary pigment and / or pigment compositions include, but are not limited to, carbazole dioxazine pigments, azo, monoazo, disazo, naphthol AS, salt type (lake), benzimidazolone, condensation, metal complexes, isoindolinone , Isoindoline and polycyclic phthalocyanine, quinacridone, perylene, perrinone, diketopyrrolopyrrole, thioindigo, anthraquinone, indanthrone, anthrapyrimidine, flavanthrone, pyranthrone, anthanthrone, Quinophthalone pigments, diketopyrrolopyrrole red ("DPPBO red"), titanium dioxide, carbon black, and mixtures thereof. The terms "pigment" and "colored filler" may be used interchangeably.

Exemplary dyes include, but are not limited to, those which are solvent and / or aqueous based, such as phthalogreen or blue, iron oxide, bismuth vanadate, anthraquinone, perylene, aluminum and quinacridone.

Exemplary tinting agents include, but are not limited to, pigments dispersed in an aqueous or water-miscible carrier, such as Aquachem 896 commercially available from Degussa Corporation, from a precision dispersion of Eastman Chemical Company Commercially available charisma colorants and maxi toner industrial colorants.

As indicated above, the colorant may be present in the form of a dispersion, including, but not limited to, nanoparticle dispersions. The nanoparticle dispersion may comprise one or more highly dispersed nanoparticle coloring and / or colorant particles that produce the desired visible color and / or opacity and / or visual effects. The nanoparticle dispersion may comprise a colorant, such as a pigment or dye, having a particle size of less than 150 nm, for example less than 70 nm, or less than 30 nm. Nanoparticles can be produced by milling an organic or inorganic pigment stock with a milling medium having a particle size of less than 0.5 mm. Exemplary nanoparticle dispersions and methods of making them are identified in U.S. Patent No. 6,875,800, which is incorporated herein by reference. Nanoparticle dispersions can also be produced by crystallization, precipitation, gas phase condensation, and chemical abrasion (i.e., partial dissolution). To minimize re-aggregation of the nanoparticles in the coating, a dispersion of resin-coated nanoparticles may be used. As used herein, "dispersion of resin-coated nanoparticles" refers to a continuous phase in which discrete "composite microparticles" containing nanoparticles and resin coatings on the nanoparticles are dispersed. Exemplary resin-coated nanoparticle dispersions and methods for their preparation are described in U.S. Patent Application Publication No. 2005/0287348, filed June 24, 2004, U.S. Provisional Application No. 60 / 482,167, filed June 24, 2003, And U.S. Patent Application No. 11 / 337,062, filed January 20, 2006, which is also incorporated herein by reference.

Exemplary special effect compositions that can be used are those that exhibit one or more cosmetic effects such as, for example, reflectance, pearlescent, metallic luster, phosphorescence, fluorescence, photochromic phenomena, photosensitivity, heat discoloration phenomena, goniocromics and / And / or < / RTI > Additional special effect compositions may provide other perceptible properties, opacity, or texture. In a non-limiting embodiment, the special effect composition can create a color shift such that the color of the coating changes when the coating is viewed at different angles. Exemplary color effect compositions are identified in U.S. Patent No. 6,894,086, which is incorporated herein by reference. The additional color effect composition may comprise transparent colored mica and / or synthetic mica, coated silica, coated alumina, transparent liquid crystal pigment, liquid crystal coating, and / or any composition wherein the interference is caused by a refractive index difference But is not produced due to the refractive index difference between the surface of the substance and air.

In certain non-limiting embodiments, the photosensitive composition and / or the photochromic composition (its color reversibly changes upon exposure to one or more light sources) can be used. The photochromic and / or photosensitive composition may be activated by exposure to a particular wavelength of irradiation. When the composition is excited, the molecular structure changes and the modified structure exhibits a new color that is different from the original color of the composition. When the exposure to the radiation is removed, the photochromic and / or photosensitive composition can be restored to its resting state, where the original color of the composition is restored. In one non-limiting embodiment, the photochromic and / or photosensitive composition can be achromatic in its unexcited state and can exhibit color in its excited state. A full color-change can occur within a few seconds to a few minutes, for example between 20 seconds and 60 seconds. Exemplary photochromic and / or photosensitive compositions include photochromic dyes.

In a non-limiting embodiment, the photosensitive composition and / or the photochromic composition may be associated and / or at least partially bound to the polymeric and / or polymeric material of the polymerizable component by, for example, covalent bonding. In contrast to some coatings in which the photosensitive composition can move out of the coating and crystallize into the substrate, the photosensitive and / or polymeric component is associated and / or at least partially bonded to the polymeric and / or polymeric component in accordance with non- The composition and / or photochromic composition migrates to a minimum outside the coating. Exemplary photosensitive and / or photochromic compositions and methods of making the same are identified in U.S. Patent Application No. 10 / 892,919, filed July 16, 2004, which is incorporated herein by reference.

In general, the colorant may be present in any amount sufficient to impart the desired visual and / or color effect to the coating composition. The colorant may comprise from 1 to 65% by weight, for example from 3 to 40% by weight or from 5 to 35% by weight, based on the total weight of the composition.

The coating composition can be combined with any other materials well known in the art of formulated surface coatings such as plasticizers, antioxidants, hindered amine light stabilizers, UV light absorbers and stabilizers, surfactants, flow control agents, thixotropic agents, For example, bentonite clay, pigments, fillers, organic co-solvents, catalysts including phosphonic acids, and other conventional adjuvants.

Besides the above-mentioned materials, the coating composition may also comprise an organic solvent. Suitable organic solvents that may be used in the coating composition include any of those listed in the preceding paragraph, as well as butyl acetate, xylene, methyl ethyl ketone, or combinations thereof.

It will be further understood that one or more of the coating compositions forming the various coating layers disclosed herein may be a "one component" ("1K"), a "two component" ("2K") or even a multicomponent composition. 1K composition will be understood to refer to a composition in which all of the coating components are maintained in the same vessel after manufacture, storage, and the like. 2K compositions or multicomponent compositions will be understood to refer to compositions in which the various ingredients are kept separately until just prior to application. 1K or 2K coating compositions may be applied to the substrate and cured by any conventional means, for example, by heating, forced venting, or the like.

The coating compositions forming the various coating layers disclosed herein can be deposited or applied onto the substrate using any technique known in the art. For example, the coating composition may be applied to the substrate by spraying, brushing, dipping and / or roll coating in any of a variety of ways, including, but not limited to, other methods. It is noted that when multiple coating compositions are applied to a substrate, one coating composition may be applied to at least a portion of the underlying coating composition after curing the underlying coating composition or prior to curing the underlying coating composition Should be. When the coating composition is applied on the uncured lower coating composition, both of the coating compositions may be cured at the same time.

The coating composition may be cured by any technique known in the art, such as, but not limited to, using thermal energy, infrared, ionizing or actinic radiation, or any combination thereof. In certain embodiments, the curing process may be performed at a temperature of? 10 ° C. In another embodiment, the curing process may be performed at a temperature of? 246 ° C. In certain embodiments, the curing process may be performed at a temperature in the range between any combination of the recited values, including the values recited in the preceding sentence. For example, the curing process may be performed at a temperature ranging from 120 < 0 > C to 150 < 0 > C. However, it should be noted that lower or higher temperatures may be used as needed to activate the curing mechanism.

In certain embodiments, at least one of the coating compositions disclosed herein is a low temperature moisture curable coating composition. As used herein, the term "low temperature moisture curable" means that after application to a substrate, ambient air, wherein the air has a relative humidity of between 10% and 100%, for example between 25% and 80% And at a temperature in the range of -10 DEG C to 120 DEG C, such as 5 DEG C to 80 DEG C, in some cases 10 DEG C to 60 DEG C, and, in still other cases, 15 DEG C to 40 DEG C, Quot;

The dry film thickness of the coating layer disclosed in the present invention may range from 0.1 mu m to 500 mu m. In another embodiment, the dry film thickness may be? 125 m, for example? 80 m. For example, the dry film thickness may range from 15 [mu] m to 60 [mu] m.

While specific embodiments of the invention have been disclosed in detail, those skilled in the art will recognize that various modifications and alternatives to their details may be developed in light of the full teachings of the above specification. Thus, it is to be understood that the specific arrangements disclosed are only illustrative and not limitative of the scope of the invention, which is to be given the full breadth of the appended claims and their equivalents.

It will be appreciated by those skilled in the art that changes may be made to the embodiments described above without departing from the broad inventive concept. It is, therefore, to be understood that the invention is not to be limited to the specific embodiments disclosed, but is to be accorded the widest scope consistent with the spirit and scope of the invention as defined by the appended claims.

Example

The coating compositions, panels and test methods used in these examples were prepared and disclosed as follows:

Alkaline Cleaner 1: A commercial alkaline cleaner available from ChemLine 2010LP / 181ALP, PPG Industries, Inc.

Alkaline cleaner 1A: An experimental alkaline cleaner having a composition similar to Chemclin 166HP, commercially available from PPG Industries, Inc.

Acid cleanser 2 - Citric acid cleanser prepared as follows. First, anhydrous citric acid (468.4 g) was dissolved in water (18,000 g). A commercial surfactant package, Chemclin 171-12 (103.4 g) was then added to the mixture. Finally, potassium hydroxide was added to the mixture to adjust the pH of the resulting mixture to 4.5.

Pretreatment composition 1: Chemphos 700, Immersion applied trithionionic Zn phosphate (commercial pretreatment product available from Pfizer Industries, Inc.).

Electrodepositable Coating Composition 1: A cationic electrocoat commercially available from Enviro-prime (R) 7000P, Pfizer Industries, Inc.

Electrodepositable Coating Composition 2: A yttrium-containing electrodepositable coating prepared according to Paint 4 of Table 1 (paragraph [0074]) of U.S. Patent Application No. 12 / 693,626.

Phosphorylated panels were purchased from ACT.

Test 1: 40 cycles of GM9540P (circulation B)

Test 2: 24 hours in the anode stripping test. The test includes a scribed panel submerged in a sodium sulfate solution, with a current of 10 mA passing through the panel. After 24 hours, the demineralized paint is removed using a tape and the width of the demineralized area is measured.

Comparison result

Experiment 1 - Comparison of Corrosion Resistance on Subsequent Coated Cleaned Panels with Electrodepositable Coating Composition 1 - Alkaline Cleaner 1 vs. Acid Cleaner 2

Cold rolled steel panels (ACT Panels) were cleaned using Cleaner 1 or Cleaner 2, rinsed with deionized water, and dried using forced hot air. The panels were electrocoated in Electrodepositable Coating Composition 1 and cured in an electric oven at 177 占 폚 for 25 minutes. The dry film thickness was 0.0005 to 0.0010 inch. Subsequently, the samples were drawn vertically and Test 1 was performed. The average scribe creep results are shown in Table 1 below.

cleaning solution Average scribe creep (mm) # 1-2 'Spray 18.7 # 2-4 'Spray 7.6

Experiment 2 - Comparison of Corrosion Resistance on Subsequent Coated Cleaned Panels with Electrodepositable Coating Composition 2 - Alkaline Cleaner 1A vs. Acid Cleaner 2

Cold rolled steel panels (ACT panel sand) were washed with alkaline cleaner 1A or pickle cleaner 2, rinsed with deionized water, and dried using forced hot air. The panels were electrocoated in Electrodepositable Coating Composition 2 and cured in an electric oven at 177 占 폚 for 25 minutes. The dry film thickness was 0.0005 to 0.0010 inch. Subsequently, the samples were drawn vertically and Test 1 was performed. The average scribe creep results are shown in Table 2 below.

cleaning solution Average scribe creep (mm) # 1A-2 ' 9.5 # 2-4 'Spray 3.3

Experiment 3 - Comparison of yttrium deposition on cleaned panel - Alkaline cleaner 1A alone Alkali cleaner 1A followed by acid cleaner 2

The cold rolled steel panel (ACT panel) was cleaned with alkaline cleaner 1A alone or alkaline cleaner 1A followed by acid cleaner 2 and rinsed with deionized water. The panels were then placed in a solution of yttrium sulfamate (800 ppm yttrium) buffered to a pH of 5.5. A current of 80 mA was passed through the solution for 2 minutes at room temperature. The panels were then rinsed with deionized water and dried using forced ventilation. After drying, the amount of yttrium deposited on the panels was measured by wave-dispersive X-ray fluorescence. The results are shown in Table 3 below.

Cleanser # 1A Cleaner # 2 Weight% Y 2 'spray --- 0.82 1 'spray 2 'spray 1.5

Experiment 4 - Comparison of Corrosion Resistance on Subsequent Coated Cleaned Panels with Electrodepositable Coating Composition 2 - Cleaner 1A vs. Cleaner 1A Cleaner 1A followed by Acid Cleaner 2 Cleaner 2 followed by Cleaner 1A - Coated Panel (with Corrosion Inhibitor)

The cold rolled steel panel (ACT panel) was cleaned with alkaline cleaner 1A, alkaline cleaner 1A followed by acid cleaner 2, acid cleaner 2 followed by alkaline cleaner 1A, and then with deionized water. The panels were then dried using forced draft. After drying, the panels were electrocoated in Electrodepositable Coating Composition 2 and cured in an electric oven at 177 ° C for 25 minutes. The dry film thickness was 0.0005 to 0.0010 inch.

A panel for Pretreatment 1 was purchased from ACT and electrocoated with Electrodepositable Coating Composition 1 for comparison.

Subsequently, the samples were drawn vertically and Test 2 was performed. The results are shown in Table 4 below.

Step 1 Step 2 Scribe creep (mm) Cleaner # 1A - 2 'Spray --- 5.52 Cleaner # 1A - 30 second spray Cleaner # 2 - 3 'Spray 3.03 Cleaner # 2 - 3 'Spray Cleaner # 1A - 30 second spray 3.00 Phosphate (Pretreatment # 1) 5.34

Claims (20)

(a) contacting the substrate with an acid; And then
(b) providing the substrate with (i) a film-forming polymer; And (ii) an antistatic coating composition comprising a corrosion inhibitor
Wherein contacting the substrate with the pretreatment composition prior to step (b) is not included. The method according to claim 1,
Wherein the corrosion inhibitor comprises a rare earth metal, lanthanide, or a combination thereof. The method according to claim 1,
Wherein the corrosion inhibitor comprises a source of yttrium. The method of claim 3,
Wherein the source of yttrium comprises a yttrium compound. The method according to claim 1,
Wherein the corrosion inhibitor comprises a source of cerium. The method according to claim 1,
Wherein the source of cerium comprises a cerium compound. The method according to claim 1,
Wherein the corrosion inhibitor comprises a source of yttrium and a source of cerium. The method according to claim 1,
Wherein the electrodepositable coating composition further comprises (iii) a silane that does not contain an ethylenically unsaturated double bond. The method according to claim 1,
Wherein the acid comprises an organic acid. The method according to claim 1,
Wherein the acid comprises an inorganic acid. The method according to claim 1,
Wherein the acid comprises an organic acid, an inorganic acid, or a mixture thereof. 10. The method of claim 9,
Wherein the organic acid comprises a carboxylic acid. 10. The method of claim 9,
Wherein the organic acid comprises citric acid. The method according to claim 1,
(c) contacting the substrate with the alkaline detergent prior to steps (a) and (b). The method according to claim 1,
(c) contacting the substrate with an alkaline detergent before and after step (b). A coated substrate formed according to the method of claim 1. A coated substrate formed according to the method of claim 8. (a) contacting the substrate with an acid;
(b) contacting the substrate with an alkaline cleaning agent; And then
(c) providing the substrate with (i) a film-forming polymer; And (ii) an antistatic coating composition comprising a corrosion inhibitor
Wherein contacting the substrate with the pretreatment composition prior to step (b) is not included. The method according to claim 1,
Wherein the corrosion inhibitor comprises a rare earth metal, lanthanide, or a combination thereof. A coated substrate formed according to the method of claim 19.