CA3233870A1 - Compositions, systems and methods for treating a substrate - Google Patents

Abstract

Disclosed herein is a conversion composition comprising a yield stress component and a corrosion inhibitor, wherein the conversion composition comprises a yield stress sufficient to overcome the effect of gravity when applied to a non-horizontal surface. The conversion composition may comprise a yield stress of at least 0.6 Pa at a frequency of 1 Hz and a temperature of 25°C when the composition is applied to a substantially vertical substrate surface at a thickness of 0.5 mil to 40 mil, may comprise a viscosity of less than less than 700 mPa.s. at a shear rate of 100 reciprocal seconds at a temperature of 25oC, a viscosity of less than 200 mPa.s. at a shear rate of 1000 reciprocal seconds at a temperature of 25oC or combinations thereof. Also disclosed are substrates comprising a film formed from the conversion composition. Also disclosed are systems and methods comprising the conversion composition and substrates formed therefrom.

Description

COMPOSITIONS, SYSTEMS AND METHODS
FOR TREATING A SUBSTRATE
CROSS-REFERENCE
[0001] This application claims the benefit of U.S. Provisional Application Nos.
63/272,554. filed October 27, 2021, and 63/269,866, filed March 24, 2022, and each entitled "COMPOSITIONS, SYSTEMS AND METHODS FOR TREATING A SUBSTRATE", the entire content of which is incorporated herein by reference.
FIELD

[0002] The present disclosure relates to compositions, systems and methods for treating a substrate.
BACKGROUND

[0003] It is known in the art of substrate protection to prevent the oxidation and degradation of the metal substrates by applying an inorganic protective coating to the metal surface.
SUMMARY

[0004] Disclosed herein are conversion compositions comprising: a yield stress component; and a corrosion inhibitor; wherein the conversion composition comprises a yield stress sufficient to overcome the effect of gravity when applied to a non-horizontal surface.

[0005] Also disclosed herein are systems for treating a metal substrate comprising: a conversion composition comprising a yield stress component, and a corrosion inhibitor, wherein the conversion composition comprises a yield stress sufficient to overcome the effect of gravity when applied to a non-horizontal surface; and a least one of a cleaning composition, a deoxidizer, and a film-forming resin.

[0006] Also disclosed herein are methods of treating a metal substrate, comprising:
contacting at least a portion of a surface of the substrate with a conversion composition comprising a yield stress component, and a corrosion inhibitor, wherein the conversion composition comprises a yield stress sufficient to overcome the effect of gravity when applied to a non-horizontal surface.

[0007] Also disclosed herein are substrates treated with the conversion compositions, systems or methods disclosed herein.

[0008] Also disclosed herein are uses of the disclosed conversion compositions to provide a composition comprising (i) a yield stress sufficient to overcome the effect of gravity when applied to a non-horizontal surface and (ii) a shear thinning rheology profile.

[0009] Also disclosed herein arc uses of the disclosed conversion compositions to provide a film that overcomes the effect of gravity when applied to a non-horizontal surface and that provides corrosion protection to the surface such that the substrate surface comprises less than 1% corrosion of a 1.376 in2 area of the substrate surface following 24 hour exposure to a neutral salt spray in a cabinet operated according to ASTM-B117 (2019) neutral salt spray testing and/or wherein the substrate passes corrosion testing according to ASTM D610-08 (2019) rating scale.
BRIEF DESCRIPTION OF THE FIGURES

[0010] FIG. 1 shows schematics of photographs taken of panels treated according to the Example disclosed herein: FIG. lA (Sample A); FIG. 1B (Sample B); FIG. 1C
(Sample C); FIG.
1D (Sample D); FIG. 1E (Sample E, comparative); FIG. 1F (Sample F, comparative); FIG. 1G
(Sample G, comparative).

[0011] FIG. 2A shows photographs of panels treated with Sample A
following exposure to neutral salt spray according to the Example disclosed herein and FIG. 2B
shows photographs of untreated panels (H) following exposure to neutral salt spray according to the Example disclosed herein.
DETAILED DESCRIPTION

[0012] For purposes of the following detailed description, it is to be understood that the disclosure may assume various alternative variations and step sequences, except where expressly specified to the contrary. Moreover, other than in any operating examples, or where otherwise indicated, all numbers such as those expressing values, amounts, percentages, ranges, subranges and fractions may be read as if prefaced by the word "about," even if the term does not expressly appear. 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 desired properties to be obtained by the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Where a closed or open-ended numerical range is described herein, all numbers, values, amounts, percentages, subranges and fractions within or encompassed by the numerical range are to be considered as being specifically included in and belonging to the original disclosure of this application as if these numbers, values, amounts, percentages, subranges and fractions had been explicitly written out in their entirety.

[0013] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the disclosure are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard variation found in their respective testing measurements.

[0014] As used herein, unless indicated otherwise, a plural term can encompass its singular counterpart and vice versa, unless indicated otherwise. For example, although reference is made herein to -a" conversion composition, -a" cleaning composition, and -a" a yield stress component, a combination (i.e., a plurality) of these components can be used.
In addition, in this application, the use of -or" means -and/or" unless specifically stated otherwise, even though "and/or" may be explicitly used in certain instances.

[0015] As used herein, "including," "containing" and like terms are understood in the context of this application to be synonymous with "comprising" and are therefore open-ended and do not exclude the presence of additional undescribed and/or unrecited elements, materials, ingredients and/or method steps.

[0016] As used herein, "consisting of' is understood in the context of this application to exclude the presence of any unspecified element, ingredient and/or method step.

[0017] As used herein, "consisting essentially of' is understood in the context of this application to include the specified elements, materials, ingredients and/or method steps "and those that do not materially affect the basic and novel characteristic(s)" of what is being described.

[0018] As used herein, the terms "on," -onto," "applied on,"
"applied onto," "formed on," "deposited on," "deposited onto," mean formed, overlaid, deposited, and/or provided on but not necessarily in contact with the surface. For example, a coating layer "formed over" a substrate does not preclude the presence of one or more other intervening coating layers of the same or different composition located between the formed coating layer and the substrate.

[0019] Unless otherwise disclosed herein, the term "substantially free," when used with respect to the absence of a particular material, means that such material, if present at all, in a composition, in a bath containing the composition, and/or in layers formed from and comprising the composition, only is present in a trace amount of 5 ppm or less based on a total weight of the composition or layer(s), as the case may be, excluding any amount of such material that may be present or derived as a result of drag-in, substrate(s), and/or dissolution of equipment. Unless otherwise disclosed herein, the term "essentially free," when used with respect to the absence of a particular material, means that such material, if present at all, in a composition, in a bath containing the composition, and/or in layers formed from and comprising the composition, only is present in a trace amount of 1 ppm or less based on a total weight of the composition or layer(s), as the case may be. Unless otherwise disclosed herein, the term "completely free,"
when used with respect to the absence of a particular material, means that such material, if present at all, in a composition, in a bath containing the composition, and/or in layers formed from and comprising the composition, is absent from the composition, the bath containing the composition, and/or layers formed from and comprising same (i.e., the composition, bath containing the composition, and/or layers formed from and comprising the composition contain 0 ppm of such material).

[0020] As used herein, a "salt" refers to an ionic compound made up of metal cations and non-metallic anions and having an overall electrical charge of zero. Salts may be hydrated or anhydrous.

[0021] As used herein, "aqueous composition" refers to a solution or dispersion in a medium that comprises predominantly water. For example, the aqueous medium may comprise water in an amount of more than 50 wt.%, or more than 70 wt.% or more than 80 wt.% or more than 90 wt.% or more than 95 wt.%, based on the total weight of the medium.
The aqueous medium may for example consist substantially of water.

[0022] As used herein, "conversion composition" refers to a composition that is capable of reacting with and chemically altering the substrate surface and binding to it to form a film that affords corrosion protection.

[0023] As used herein, the term "transition metal" refers to an element that is in any of Groups IIIB to VIIIB, TB, and JIB of the CAS version of the Periodic Table of Elements excluding the lanthanide series elements and elements 89-103, as is shown, for example, in the Handbook of Chemistry and Physics, 63rd edition (1983), corresponding to Groups 3 to 12 in the actual IUPAC numbering.

[0024] As used herein, the term "transition metal compound"
refers to compounds that include at least one clement that is a transition metal of the CAS version of the Periodic Table of Elements.

[0025] As used herein, the term "Group IA metal" refers to an element that is in Group IA of the CAS version of the Periodic Table of Elements as is shown, for example, in the Handbook of Chemistry and Physics, 63rd edition (1983), corresponding to Group 1 in the actual IUPAC numbering.

[0026] As used herein, the term "Group IA metal compound- refers to compounds that include at least one element that is in Group IA of the CAS version of the Periodic Table of Elements.

[0027] As used herein, the term -Group IIA metal" refers to an element that is in Group IA of the CAS version of the Periodic Table of Elements as is shown, for example, in the Handbook of Chemistry and Physics, 63rd edition (1983), corresponding to Group 2 in the actual IUPAC numbering.

[0028] As used herein, the term "Group IIA metal compound" refers to compounds that include at least one element that is in Group IIA of the CAS version of the Periodic Table of Elements.

[0029] As used herein, the term "Group IIIB metal" refers to yttrium and scandium of the CAS version of the Periodic Table of Elements as is shown, for example, in the Handbook of Chemistry and Physics, 63rd edition (1983), corresponding to Group 3 in the actual IUPAC
numbering. For clarity, "Group MB metal" expressly excludes lanthanide series elements.

[0030] As used herein, the term "Group IIIB metal compound"
refers to compounds that include at least one element that is in group IIIB of the CAS version of the Periodic Table of Elements as defined above.

[0031] As used herein, the term "Group 1VB metal" refers to an element that is in Group IVB of the CAS version of the Periodic Table of Elements as is shown, for example, in the Handbook of Chemistry and Physics, 631d edition (1983), corresponding to Group 4 in the actual IUPAC numbering.

[0032] As used herein, the term "Group IVB metal compound" refers to compounds that include at least one element that is in Group IVB of the CAS version of the Periodic Table of Elements.

[0033] As used herein, the term -Group VB metal" refers to an element that is in Group VB of the CAS version of the Periodic Table of Elements as is shown, for example, in the Handbook of Chemistry and Physics, 63rd edition (1983), corresponding to Group 5 in the actual IUPAC numbering.

[0034] As used herein, the term "Group VB metal compound" refers to compounds that include at least one element that is in Group VB of the CAS version of the Periodic Table of Elements.

[0035] As used herein, the term "Group VIB metal" refers to an element that is in Group VIB of the CAS version of the Periodic Table of Elements as is shown, for example, in the Handbook of Chemistry and Physics, 63rd edition (1983), corresponding to Group 6 in the actual IUPAC numbering.

[0036] As used herein, the term -Group VIB metal compound" refers to compounds that include at least one element that is in Group V1B of the CAS version of the Periodic Table of Elements.

[0037] As used herein, the term "Group VIIB metal" refers to an element that is in Group VIIB of the CAS version of the Periodic Table of Elements as is shown, for example, in the Handbook of Chemistry and Physics, 63rd edition (1983), corresponding to Group 7 in the actual IUPAC numbering.

[0038] As used herein, the term "Group VIIB metal compound"
refers to compounds that include at least one element that is in Group VIIB of the CAS version of the Periodic Table of Elements.

[0039] As used herein, the term "Group JIB metal" refers to an element that is in Group 11B of the CAS version of the Periodic Table of Elements as is shown, for example. in the Handbook of Chemistry and Physics, 63rd edition (1983), corresponding to Group 12 in the actual IUPAC numbering.

[0040] As used herein, the term "Group JIB metal compound" refers to compounds that include at least one element that is in Group JIB of the CAS version of the Periodic Table of Elements.

[0041] As used herein, the term "lanthanide series elements"
refers to elements 57-71 of the CAS version of the Periodic Table of Elements and includes elemental versions of the lanthanide series elements. According to the present disclosure, the lanthanide series elements may be those which have both common oxidation states of +3 and +4, referred to hereinafter as +3/+4 oxidation states.

[0042] As used herein, the term "lanthanide compound" refers to compounds that include at least one of elements 57-71 of the CAS version of the Periodic Table of Elements.

[0043] As used herein, the term "halogen" refers to any of the elements fluorine, chlorine, bromine, iodine, and astatine of the CAS version of the Periodic Table of Elements, corresponding to Group VITA of the CAS version of the Periodic Table of Elements.

[0044] As used herein, the term "halide" refers to compounds that include at least one halogen.

[0045] As used herein, the term -aluminum," when used in reference to a substrate, refers to substrates made of or comprising aluminum and/or aluminum alloy, and clad aluminum substrates.

[0046] "Pitting corrosion," as used herein, refers to the localized formation of corrosion by which cavities or holes are produced in a substrate. The term "pit," as used herein, refers to such cavities or holes resulting from pitting corrosion and is characterized by (1) a rounded, elongated or irregular appearance when viewed normal to the test panel surface, (2) a "comet-tail", a line, or a "halo" (i.e., a surface discoloration) emanating from the pitting cavity, and/or (3) the presence of corrosion byproduct (e.g., white, grayish or black granular, powdery or amorphous material) inside or immediately around the pit. Visual inspection using a microscope with 10X magnification may be used to determine the presence of corrosion byproducts when corrosion byproducts are not visible with the unaided eye.

[0047] Unless otherwise disclosed herein, as used herein, the terms "total composition weight", "total weight of a composition" or similar terms refer to the total weight of all ingredients being present in the respective composition including any carriers and solvents.

[0048] As used herein, the term "yield stress" refers to the stress corresponding to the yield point above which a material begins to flow and below which the material behaves as a predominantly elastic solid.

[0049] As used herein, the term "yield stress component" refers to a material that behaves as a predominantly elastic solid below the yield stress (elastic modulus greater than viscous modulus) and that begins to flow above the yield stress, i.e., the "yield stress component" imparts yield stress to the conversion composition.

[0050] As used herein, the term "complex substrate" refers to a substrate with portions having a variety of orientations, such as horizontal, vertical, non-horizontal, substantially vertical and combinations thereof.

[0051] As used herein, the term "horizontal," when used with respect to a surface, refers to parallel to the plane of the horizon.

[0052] As used herein, the term "vertical,- when used with respect to a surface, refers to 90 as measured from the horizontal plane.

[0053] As used herein, the term "non-horizontal" or "inclined,"
when used with respect to a surface, refers to any angle greater than 0 as measured from the horizontal plane.

[0054] As used herein, the term "substantially vertical," when used with respect to a surface, refers to 70 to 1100 as measured from the horizontal plane.

[0055] As used herein, the term "cling" refers to a yield stress sufficient to overcome the effect of gravity when a composition is applied to a non-horizontal surface.
Conversion Compositions

[0056] The present disclosure is directed to conversion compositions. The conversion composition may comprise, or may consist essentially of, or may consist of: a yield stress component; and a corrosion inhibitor; wherein the composition comprises a yield stress sufficient to overcome the effect of gravity when applied to a non-horizontal surface.
The conversion composition may comprise a yield stress fluid that provides corrosion protection to substrate surfaces. The yield stress component may be dissolved or dispersed in a fluid medium. The fluid medium may comprise an aqueous medium.

[0057] The conversion composition may comprise a yield stress of at least 0.6 Pa at a frequency of 1 Hz and a temperature of 25 C when the composition is applied at a thickness of 0.5 mil to 40 mil to a substantially vertical substrate surface, such as at least 0.7 Pa, such as at least 0.8 Pa, such as at least 0.9 Pa, such as at least 1.0 Pa, such as at least 2.0 Pa, such as at least 3.0 Pa, such as at least 4.0 Pa, such as at least 5.0 Pa, such as at least 6.0 Pa, such as at least 7.0 Pa, such as at least 8.0 Pa, such as at least 9.0 Pa, such as at least 10.0 Pa.

[0058] The conversion composition may comprise a yield stress greater than 10.0 Pa as long as the composition maintains shear thinning behavior (i.e., as long as the composition has a low viscosity with a high shear rate) as described below, such as a yield stress of no more than 50.0 Pa at a frequency of 1 Hz and a temperature of 25 C when the composition is applied at a thickness of 0.5 mil to 40 mil to a substantially vertical substrate surface, such as no more than 40.0 Pa, such as no more than 30.0 Pa, such as no more than 20.0 Pa, such as no more than 20.0 Pa.

[0059] The conversion composition may comprise a yield stress of 0.6 Pa to 50.0 Pa at a frequency of 1 Hz and a temperature of 25 C when the composition is applied at a thickness of 0.5 mil to 40 mil to a substantially vertical substrate surface, such as 0.7 Pa to 50.0 Pa, such as 0.8 Pa to 50.0 Pa, such as 0.9 Pa to 50.0, such as 1.0 Pa to 40.0 Pa, such as 2.0 Pa to 40.0 Pa, such as 3.0 Pa to 30.0 Pa, such as 4.0 Pa to 20.0 Pa, such as 5.0 Pa to 20.0 Pa, such as 6.0 Pa to 20.0 Pa, such as 7.0 Pa to 20.0 Pa, such as 8.0 Pa to 20.0 Pa, such as 9.0 Pa to 20.0 Pa, such as 10.0 Pa to 20.0 Pa.

[0060] Yield stress may be determined in water at 25 C using a DHR-2 rheometer from TA Instruments with a concentric cylinder geometry or equivalent instruments.
Elastic (G') and viscous (G") moduli may be determined as a function of increasing stress amplitude at a frequency of 1 Hz and the crossover of G' and G" may be used to estimate the yield stress. One skilled in the art will understand that the yield stress required to support a coating on a non-horizontal surface will vary with the thickness of the coating and the angle of incline.

[0061] The conversion composition may comprise a viscosity of less than 700 mPa.s. at a shear rate of 100 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 600 mPa.s. at a shear rate of 100 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 500 mPa.s. at a shear rate of 100 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 400 mPa.s. at a shear rate of 100 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 300 mPa.s. at a shear rate of 100 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 200 mPa.s. at a shear rate of 100 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 100 mPa.s.
at a shear rate of 100 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 75 mPa.s. at a shear rate of 100 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 70 mPa.s. at a shear rate of 100 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 60 mPa.s. at a shear rate of 100 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 55 mPa.s. at a shear rate of 100 reciprocal seconds at a temperature of 25 C.

[0062] The conversion composition may comprise a viscosity of less than 200 mPa.s. at a shear rate of 1000 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 175 mPa.s. at a shear rate of 1000 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 150 mPa.s. at a shear rate of 1000 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 125 mPa.s. at a shear rate of 1000 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 100 mPa.s. at a shear rate of 1000 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 80 mPa.s.
at a shear rate of 1000 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 60 mPa.s. at a shear rate of 1000 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 50 mPa.s. at a shear rate of 1000 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 40 mPa.s. at a shear rate of 1000 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 30 mPa.s. at a shear rate of 1000 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 20 mPa.s. at a shear rate of 1000 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 15 mPa.s. at a shear rate of 1000 reciprocal seconds at a temperature of 25 C.

[0063] Viscosity may be determined using a Discovery HR-2 Rheometer with concentric cylinders from TA Instruments or equivalent instruments.

[0064] As mentioned above, the conversion composition may comprise a yield stress component. The yield stress component may comprise a crosslinked microgel polymer, a network-forming polymer or combinations thereof.

[0065] Suitable crosslinked microgel polymers comprise polyelectrolyte microgel polymers, crosslinked nonionic microgel polymers or combinations thereof. In examples, the crosslinked microgel polymer may be pH-activated and may comprise a pH-responsive moiety.
The pH-responsive moiety may be either acidic or alkaline. In use, when the crosslinked microgel polymers are neutralized by the addition of an acid or a base (resulting in ionization of the acidic or basic groups), the polymers swell to form a randomly close-packed network of swollen crosslinked microgel particles that impart rheological features such as yield stress. In examples, the polymers may comprise vinyls.

[0066] The crosslinked microgel polymer may comprise a pKa of at least 3, such as at least 3.2, and may have a pKa of no more than 7, such as no more than 4, such as no more than 3.7. The crosslinked microgel polymer may comprise a pKa of 3 to 7, such as a pKa of 3 to 4, such as a pKa of 3.2 to 3.7.

[0067] Suitable examples of crosslinked microgel polymers include crosslinked carboxylic acid polymers based on maleic acid, itaconic acid or (meth)acrylic acid monomers.
Microgel polymers including polymers based on (meth)acrylic acid monomers are commercially available, for example, as Carbopol from The Lubrizol Corporation. As used herein, "(meth)acrylate" refers to either/or methacrylate or acrylate and "(meth)acrylic" refers to either/or methacrylic acid and acrylic acid.

[0068] Other suitable examples of crosslinked microgel polymers include alkali swellable polymers based on alkyl acrylic, (meth)acrylic acid, carboxylic acid, non-acid vinyl monomers and combinations thereof. The crosslinked alkali swellable polymer may be hydrophobically modified, may be amphiphilic and/or may be activated by a surfactant. As used herein, -amphiphilic" means molecules having a polar water-soluble group attached to a water-insoluble hydrocarbon chain.

[0069] As noted above, the yield stress component may comprise a network-forming polymer. The network-forming polymer may comprise a biopolymer. The biopolymer may comprise an ionic polymer such as an anionic polysaccharide. In other examples, the biopolymer may comprise a neutral polysaccharide. Suitable examples of biopolymers include xanthan gum, welan gum, diutan gum, scleroglucan or combinations thereof.

[0070] The biopolymers disclosed herein may comprise no more than 4 charged groups per monosaccharide unit, such as no more than 3 charged groups per monosaccharide unit, such as no more than 2 charged groups per monosaccharide unit, such as no more than I charged group per monosaccharide unit.

[0071] The biopolymers disclosed herein may comprise at least 1 shielded charged group. Charged groups in monosaccharide unit may be shielded by hydrophilic side groups to minimize interactions with monovalent and polyvalent cations that comprise the conversion coating composition.

[0072] The conversion composition may comprise the yield stress component in an amount of at least 0.2 percent by weight based on total weight of the composition, such as at least such as at least 0.3 percent by weight based on total weight of the composition, such as at least 0.4 percent by weight based on total weight of the composition, such as at least 0.5 percent by weight based on total weight of the composition, such as at least 0.6 percent by weight based on total weight of the composition, such as at least 0.7 percent by weight based on total weight of the composition, such as at least 0.8 percent by weight based on total weight of the composition, such as at least 0.9 percent by weight based on total weight of the composition, such as at least 1.0 percent by weight based on total weight of the composition, such as at least 1.5 percent by weight based on total weight of the composition, such as at least 2.0 percent by weight based on total weight of the composition.

[0073] The conversion composition may comprise the yield stress component in any amount such that the composition comprises yield stress and shear thinning properties described above while not negatively corrosion performance and coating behaviors such as leveling, ease of application and the like.

[0074] As mentioned above, the conversion composition may comprise a trivalent chromium. The trivalent chromium may be present in the conversion composition in an amount of at least 0.005 g/L based on total weight of the conversion composition, such as at least 0.01 g/L, such as at least 0.5g/L, and in some instances, may be present in the conversion composition in an amount of no more than 2 g/L based on total weight of the conversion composition, such as no more than 1.5 g/L, such as no more than 1 g/L. The trivalent chromium may be present in the conversion composition in an amount of 0.005 g/L to 2 g/L based on total weight of the conversion composition, such as 0.01 g/L to 1.5 g/L, such as 0.5 g/L to 1 g/L.

[0075] The trivalent chromium may be present in the conversion composition as a compound, such as a trivalent chromium-containing salt. Thus, the composition may further comprise an anion that may be suitable for forming a salt with the trivalent chromium, including for example a halogen, a sulfate, a nitrate, an acetate, a carbonate, a hydroxide, or combinations thereof. Suitable examples of trivalent chromium salts include but are not limited to basic chromium sulphate, chromium (111) potassium sulfate. chromium (111) sulfate, chromium (111) halide (such as chromium (III) chloride) or combinations thereof. Trivalent chromium salts may be present in the conversion composition in their hydrated form or their anhydrous form.

[0076] The anion suitable for forming the trivalent chromium salt may be present in the conversion composition in an amount of at least 0.01 g/L based on total weight of the conversion composition, such as at least 0.5 g/L, such as at least 1 g/L, and in some instances, may be present in an amount of no more than 4 g/L based on total weight of the conversion composition, such as no more than 3.5 g/L, such as no more than 2 g/L. The anion suitable for forming the trivalent chromium salt may be present in the conversion composition in an amount of 0.01 g/L
to 4 g/L based on total weight of the conversion composition, such as 0.5 g/L
to 3.5 g/L, such as 1 g/L to 2 g/L.

[0077] Optionally, the conversion composition may further comprise at least one coinhibitor. In examples, the coinhibitor may comprise a Group IIA metal, a transition metal, a lanthanide series metal, a Group JIB metal, an azole, or combinations thereof.
In examples, the Group IIA metal may comprise magnesium; the transition metal may comprise a Group IIIB
metal such as yttrium, scandium, or combinations thereof, a Group IVB metal such as zirconium, titanium, hafnium, or combinations thereof, a Group VB metal such as vanadium, a Group VIB
metal other than chromium such as molybdenum, and/or a Group VIIB metal such as manganese; the lanthanide series metal may comprise cerium, praseodymium, terbium, or combinations thereof; and the Group JIB metal may comprise zinc. Optionally, the conversion composition may be substantially free, or essentially free, or completely free, of a Group 11B
metal.

[0078] The coinhibitor may be present in the conversion composition as a compound such as a salt. As such, the conversion composition may further comprise an anion that may be suitable for forming a salt with the metals of the coinhibitor(s), such as a halogen, a nitrate, a sulfate, a phosphate, a silicate (orthosilicates and metasilicates), a carbonate, an acetate, a hydroxide, a fluoride, and the like. Accordingly, the conversion composition may comprise sulfur-containing coinhibitors, phosphorous-containing coinhibitors, fluorine-containing coinhibitors, and the like.

[0079] The cation of the coinhibitor may be present in the conversion composition in an amount of at least 0.05 g/L based on total weight of the conversion composition, such as at least 0.07 g/L, such as at least 0.5 g/L, and in some instances, may be present in an amount of no more than 5 g/L based on total weight of the conversion composition, such as no more than 4 g/L, such as no more than 1 g/L. The cation of the coinhibitor may be present in the conversion composition in an amount of 0.05 g/L to 5 g/L based on total weight of the conversion composition, such as 0.07 g/L to 4 g/L, such as 0.5 g/L to 1 g/L.

[00801 The conversion composition may optionally further comprise an indicator compound, so named because it indicates, for example, the presence of a chemical species, such as a metal ion, the pH of a composition, and the like. An "indicator", "indicator compound", and like terms as used herein refer to a compound that changes color in response to some external stimulus, parameter, or condition, such as the presence of a metal ion, or in response to a specific pH or range of pHs.
[0081] The indicator compound may be any indicator known in the art that indicates the presence of a species, a particular pH, and the like. For example, a suitable indicator may be one that changes color after forming a metal ion complex with a particular metal ion. The metal ion indicator is generally a highly conjugated organic compound. A "conjugated compound- as used herein, and as will be understood by those skilled in the art, refers to a compound having two double bonds separated by a single bond, for example two carbon-carbon double bonds with a single carbon-carbon bond between them. Any conjugated compound can be used according to the present disclosure.
[0082] Similarly, the indicator compound can be one in which the color changes upon change of the pH; for example, the compound may be one color at an acidic or neutral pH and change color in an alkaline pH, or vice versa. Such indicators are well known and widely commercially available. An indicator that "changes color upon transition from a first pH to a second pH" (i.e., from a first pH to a second pH that is more or less acidic or alkaline) therefore has a first color (or is colorless) when exposed to a first pH and changes to a second color (or goes from colorless to colored) upon transition to a second pH (i.e., one that is either more or less acidic or alkaline than the first pH). For example, an indicator that "changes color upon transition to a more alkaline pH (or less acidic pH) goes from a first color/colorless to a second color/color when the pH transitions from acidic/neutral to alkaline. For example, an indicator that "changes color upon transition to a more acidic pH (or less alkaline pH) goes from a first color/colorless to a second color/color when the pH transitions from alkaline/neutral to acidic.
[0083] Non-limiting examples of such indicator compounds include methyl orange, xylenol orange, catechol violet, bromophenol blue, green and purple, eriochrome black T, Celestine blue, hematoxylin, calmagite, gallocyanine, and combinations thereof. Optionally, the indicator compound may comprise an organic indicator compound that is a metal ion indicator.
Nonlimiting examples of indicator compounds include those found in Table 1.
Fluorescent indicators, which will emit light in certain conditions, can also be used according to the present disclosure, although the use of a fluorescent indicator also may be specifically excluded. That is, alternatively, conjugated compounds that exhibit fluorescence are specifically excluded. As used herein, "fluorescent indicator" and like terms refer to compounds, molecules, pigments, and/or dyes that will fluoresce or otherwise exhibit color upon exposure to ultraviolet or visible light.
To "fluoresce" will be understood as emitting light following absorption of shorter wavelength light or other electromagnetic radiation. Examples of such indicators, often referred to as "tags,"
include acridine, anthraquinone, coumarin, diphenylmethane, diphenylnaphthlymethane, quinoline, stilbene, triphenylmethane, anthracine and/or molecules containing any of these moieties and/or derivatives of any of these such as rhodamines, phenanthridines, oxazines, fluorones, cyanines and/or acridines.

Compound Structure CAS Reg. No.
Catechol Violet 0 115-41-3 Synonyms: OH
OH
Catecholsulfonphthalein; U=S=0 Pyrocatecholsulfonephthalein; HO
Pyrocatechol Violet HO
Xylenol Orange 3618-43-Synonym:

3,3 '-Bis[N,N-bis(carboxymethyl)aminomethyl]- 4 o-cresolsulfonephthalein tetrasodium OH
z 9 salt tis r OH
[0084] According to the present disclosure, the conjugated compound useful as indicator may for example comprise catechol violet, as shown in Table 1. Catechol violet (CV) is a sulfone phthalein dye made from condensing two moles of pyrocatechol with one mole of o-sulfobenzoic acid anhydride. It has been found that CV has indicator properties and when incorporated into compositions having metal ions, it forms complexes, making it useful as a complexiometric reagent. As the composition containing the CV chelates metal ions coming from the metal substrate (i.e., those having hi- or higher valence), a generally blue to blue-violet color is observed.
[0085] Xylenol orange, as shown in Table 1, may likewise be employed in the compositions according to the present disclosure. It has been found that xylenol orange has metal ion (i.e., those having bi- or higher valence) indicator properties and when incorporated into compositions having metal ions, it forms complexes, making it useful as a complexiometric reagent. As the composition containing the xylenol orange chelates metal ions, a solution of xylenol orange turns from red to a generally blue color.
[0086] According to the present disclosure, the indicator compound may be present in the conversion composition in an amount of at least 0.01 g/1000 g conversion composition, such as at least 0.05 g/1000 g conversion composition, and in some instances, no more than 3 g/1000 g conversion composition, such as no more than 0.3g/1000 g conversion composition. According to the present disclosure, the indicator compound may be present in the conversion composition in an amount of 0.01 g/1000 g conversion composition to 3 g/1000 g conversion composition, such as 0.05 g/1000 g conversion composition to 0.3 g/1000 g conversion composition.
[0087] The indicator compound changing color in response to a certain external stimulus provides a benefit when using the conversion composition in that it can serve, for example, as a visual indication that a substrate has been treated with the composition. For example, a conversion composition comprising an indicator that changes color when exposed to a metal ion that is present in the substrate will change color upon complexing with metal ions in that substrate; this allows the user to see that the substrate has been contacted with the composition.
Similar benefits can be realized by depositing an alkaline or acid layer on a substrate and contacting the substrate with a composition of the present disclosure that changes color when exposed to an alkaline or acidic pH.
[0088] The pH of the conversion composition may, in some instances, be less than 7, such as less than 5, such as 1.5 to 6.9, such as 2.0 to 6.0, such as 2.5 to 4.5, such as 2.8 to 4.5.
The pH may be adjusted using, for example, any acid and/or base as is necessary. Thus, the pH
of the conversion composition may be maintained through the inclusion of an acidic material, including water soluble and/or water dispersible acids, such as nitric acid, sulfuric acid, and/or phosphoric acid. Additionally, the pH of the composition may be maintained through the inclusion of a basic material, including water soluble and/or water dispersible bases, such as sodium hydroxide, sodium carbonate, potassium carbonate, potassium hydroxide, ammonium hydroxide, ammonia, and/or amines such as triethylamine, methylethyl amine, or mixtures thereof.
[0089] The conversion composition may exclude hexavalent chromium or compounds that include hexavalent chromium. Non-limiting examples of such materials include chromic acid, chromium trioxide, chromic acid anhydride, dichromate salts, such as ammonium dichromate, sodium dichromate, potassium dichromate, and calcium, barium, magnesium, zinc, cadmium, and strontium dichromate. When a composition and/or a coating or a layer formed from the composition is substantially free, essentially free, or completely free of hexavalent chromium, this includes hexavalent chromium in any form, such as, but not limited to, the hexavalent chromium-containing compounds listed above.
[0090] Thus, optionally, the conversion composition and/or coatings or layers, respectively, deposited from the same may be substantially free, may be essentially free, and/or may be completely free of one or more of any of the elements or compounds listed in the preceding paragraph. A composition and/or coating or layer, respectively, formed from the same that is substantially free of hexavalent chromium or derivatives thereof means that hexavalent chromium or derivatives thereof are not intentionally added, but may be present in trace amounts, such as because of impurities or unavoidable contamination from the environment. In other words, the amount of material is so small that it does not affect the properties of the composition; in the case of hexavalent chromium, this may further include that the element or compounds thereof are not present in the compositions and/or coatings or layers, respectively, formed from the same at such a level that it causes a burden on the environment. The term "substantially free" means that the composition and/or coating or layers, respectively, formed from the same contain less than 10 ppm of any or all of the elements or compounds listed in the preceding paragraph, based on total weight of the composition or the layer, respectively, if any at all. The term "essentially free" means that the composition and/or coatings or layers, respectively, formed from the same contain less than 1 ppm of any or all of the elements or compounds listed in the preceding paragraph, if any at all. The term "completely free" means that the composition and/or coatings or layers, respectively, formed from the same contain less than 1 ppb of any or all of the elements or compounds listed in the preceding paragraph, if any at all.
[0091] The conversion composition may comprise an aqueous medium and may optionally contain other materials such as nonionic surfactants and auxiliaries conventionally used in the art of conversion compositions. In the aqueous medium, water dispersible organic solvents, for example, alcohols with up to about 8 carbon atoms such as methanol, isopropanol, and the like, may be present; or glycol ethers such as the monoalkyl ethers of ethylene glycol, diethylene glycol, or propylene glycol, and the like. When present, water dispersible organic solvents are typically used in amounts up to about 10% by volume, based on the total volume of aqueous medium. Additionally, in the aqueous medium, thickeners such as cellulosic, silicated, or acrylic thickeners may be present. When present, such thickeners are typically used in amounts of at least 0.00001 wt.%, such as at least 0.5 wt.%, and in some instances, no more than wt.%, such as no more than 1 wt.%. When present, such thickeners are typically used in amounts of 0.00001 wt.% to 5 wt.%, such as 0.5 wt.% to 1 wt/%, based on total weight of the composition. As used herein, "thickener" refers to materials that are substantially free of crosslinking. and "substantially free of crosslinking" refers to materials that have a weight average molecular weight, as determined by gel permeation chromatography, of less than 100,000.
[0092] Other optional materials that may be included in the conversion composition include surfactants that function as defoamers or substrate wetting agents.
Anionic, cationic, amphoteric, and/or nonionic surfactants may be used. Defoaming surfactants may optionally be present at levels up to 1 wt.%, such as up to 0.1 wt.%, and wetting agents are typically present at levels up to 2 wt.%, such as up to 0.5 wt.%, based on the total weight of the conversion composition.
[0093] As mentioned above, the conversion composition may comprise a carrier, often an aqueous medium, so that the conversion composition is in the form of a solution or dispersion of the yield stress component, the trivalent chromium compound and optionally other metal compounds and/or coinhibitors in the carrier.
[0094] It has been surprisingly discovered that the conversion compositions disclosed herein (i) comprise a yield stress sufficient for the conversion composition to cling to a non-horizontal substrate, such as a substantially vertical substrate, (ii) comprise a shear thinning rheology profile (a decrease in viscosity with increasing shear rate) with sufficiently low viscosity at the higher shear rates to enable easy application to a substrate surface, and (iii) provide corrosion protection to substrates exposed to neutral salt spray testing for 24 hours.
Systems [0095] Also disclosed herein are systems for treating a substrate. The system may comprise, or consist essentially of, or consist of, any of the conversion compositions described herein above and at least one of a cleaning composition, a deoxidizer, a film-forming resin or combinations thereof.
[0096] As used herein, "cleaning compositions- included in the systems and methods of the present disclosure may have deoxidizing functionality in addition to degreasing characteristics and/or may eliminate the need for application of separate treatment compositions that deoxidize the substrate surface.
[0097] As mentioned above, the cleaning composition may be alkaline and may have a pH greater than 7, such as greater than 9, such as greater than 11. The pH of the cleaning composition may be 7 to 13, such as 9 to 12.7. In other instances, the cleaning composition may be acidic and may have a p1-1 less than 7, such as less than 6, such as less than 5.5. The p1-1 of the cleaning composition may be 0.5 to 6, such as 1.5 to 4.5.
[0098] The cleaning composition may include commercially available alkaline cleaners, including ChemkleenTM 163, 177, 611L. 490MX, 2010LP, and 181ALP, Ultrax 32, Ultrax 97, and Ultrax 94D, each of which are commercially available from PPG Industries, Inc. (Cleveland, OH), and any of the DFM Series, RECC 1001, and 88X1002 cleaners commercially available from PRC-DeSoto International (Sylmar, CA), and Turco 4215-NCLT and Ridolene commercially available from Henkel Technologies (Madison Heights, MI), and any of the SOCOCLEAN series of cleaners commercially available from Soconaore.
Optionally, the cleaner may be substantially free, or essentially free, or completely free of borate.
[0099] The cleaning composition may comprise a hydroxide-containing and/or a phosphate-containing compound and/or a metasilicate. The hydroxide ion of the hydroxide-containing compound, if present at all, may be present in the cleaning composition in an amount of 0.05 to 25 g/1000 g solution, for example 18 to 20 g/1000 g solution based on total weight of the cleaning composition. In cleaning compositions having a phosphate-containing compound, the phosphate may comprise phosphate (PO4)3-, di-hydrogen phosphate (1-12PO4)-, and/or pyrophosphate (P207)4-, for example, phosphate (PO4)3- and/or pyrophosphate (P207)4-. The phosphate may be present in the composition in an amount of 50 g/1000 g solution to 10 g/1000 g solution, for example 70 g/1000 g solution to 90 g/1000 g solution based on total weight of the cleaning composition. Other nonlimiting examples of suitable phosphate-containing compounds include organ phosphates, such as DequestO obtainable from Monsanto (St.
Louis, MO).
[0100] The cleaning composition may comprise hydrogen and/or minerals such as iron, potassium, etc. For example, the cleaning composition may comprise phosphoric acid, acetic acid, nitric acid, sulfuric acid, hydrofluoric acid, hydrochloric acid, and/or iron sulfate.
[0101] The cleaning composition may optionally comprise a corrosion inhibitor comprising a metal compound and/or an azole compound. The metal of the metal compound in the corrosion inhibitor (when included) may comprise various metals which have corrosion inhibiting characteristics. For example, the metal may comprise a lanthanide series element, a Group IA metal, a Group IIA metal, and/or a transition metal, such as any of those described above.
[0102] The cleaning composition may comprise a corrosion inhibitor comprising a metal at a concentration of at least 0.01 g/L, such as at least 0.05 g/L, such as at least 0.1 g/L, such as at least 1 g/L, and in some instances may be present in the cleaning composition at a concentration of no more than 25 g/L, such as no more than 16 g/L, such as no more than 10 g/L, such as no more than 5 g/L. The metal can be present in the cleaning composition at a concentration of 0.01 g/L of composition to 25 g/L of composition, such as 0.05 g/L to 16 g/L, such as 0.1 g/L to 10 g/L, such as 1 g/L to 5 g/L based on total weight of the cleaning composition.
[0103] The corrosion-inhibiting metal may be provided in the cleaning composition in the form of a salt having an anion and the metal as the cation of the salt.
The anion of the salt may be any suitable anion capable of forming a salt with the lanthanide series element, Group IA
metal, Group 11A metal, and/or transition metal. Nonlimiting examples of such anions include a carbonate, a hydroxide, a nitrate, a halogen, a sulfate, a phosphate and/or a silicate (e.g., orthosilicates and metasilicates). Optionally, the cleaning composition may include at least two metal salts, and the at least two metal salts may comprise different anions and/or cations from each other. For example, the at least two metal salts may comprise different anions but the same cations or may comprise different cations but the same anions.

[0104] As mentioned above, the cleaning composition may comprise a halogen. The halogen may be provided in the composition in the form of a salt with the metals described above. The halogen may be present in the cleaning composition in an amount of at least 0.2 g/L
based on total weight of the cleaning composition, and in some instances may he present in an amount of no more than 1.5 g/L based on total weight of the cleaning composition. The halogen may be present in the cleaning composition in an amount of 0.2 g/L to 1.5 g/L
based on total weight of the cleaning composition. In other examples, the cleaning composition may be substantially free, or essentially free, or completely free, of halogen.
[0105] Optionally, the cleaning composition may further comprise a nitrogen-containing heterocyclic compound. The nitrogen-containing heterocyclic compound may include cyclic compounds having 1 nitrogen atom, such as pyrroles, and azole compounds having 2 or more nitrogen atoms, such as pyrazoles, imidazoles, triazoles, tetrazoles and pentazoles, 1 nitrogen atom and 1 oxygen atom, such as oxazoles and isoxazoles, or 1 nitrogen atom and 1 sulfur atom, such as thiazoles and isothiazoles. Nonlimiting examples of suitable azole compounds include 2,5-dimercapto-1,3.4-thiadiazole (CAS:1072-71-5),11-1-benzotriazole (CAS: 95-14-7), 1H-1,2,3-triazole (CAS: 288-36-8), 2-amino-5-mercapto-1,3,4-thiadiazole (CAS: 2349-67-9), also named 5-amino-1,3,4-thiadiazc-)1e-2-thiol, and 2-amino-1,3,4-thiadiazole (CAS: 4005-51-0). In some embodiments, for example, the azole compound comprises 2,5-dimercapto-1,3,4-thiadiazole.
Additionally, the nitrogen-containing heterocyclic compound may be in the form of a salt, such as a sodium salt.
[0106] The nitrogen-containing heterocyclic compound may be present in the cleaning composition in an amount of at least 0.5 g/L based on total weight of the cleaning composition, such as at least 1 g/L based on total weight of the cleaning composition, such as at least 5 g/L
based on total weight of the cleaning composition, and in some instances may be present in an amount of no more than 15 g/L based on total weight of the cleaning composition, such as no more than 12 g/L based on total weight of the cleaning composition, such as no more than 10 g/L
based on total weight of the cleaning. The nitrogen-containing heterocyclic compound may be present in the cleaning composition in an effective corrosion inhibiting amount, for example, 0.5 g/L to 15 g/L based on total weight of the cleaning composition, such as 1 g/L
to 12 g/L based on total weight of the cleaning composition, such as 5 g/L to 10 g/L based on total weight of the cleaning composition.

[0107] The cleaning composition may contain additives such as, but not limited to, carbonates, surfactants, chelators, thickeners, allantoin, polyvinylpyrrolidone, 2,5-dimercapto-1,3,4-thiadiazole, halides, adhesion promotors, such as adhesion promoting silanes (e.g., silanes having an amine and/or hydroxyl functionality; or a zirconium alkoxide and/or a si lanc coupling agent) and alcohols (collectively, "additives"). Surfactants suitable for use in the present disclosure include Dynol 604 and CarhowetTM DC01 surfactant both commercially available from Air Products, having offices in Allentown, PA. and Triton X-100 available from The Dow Chemical Company (Midland MI). Such additives, if present at all, may be present in the cleaning composition in an amount of at least 0.01 g/L based on total weight of the cleaning composition, such as at least 0.5 g/L, such as at least 1 g/L, such as at least 10 g/L, such as at least 20 g/L, and may be present in the cleaning composition in an amount of no more than 60 g/L based on total weight of the cleaning composition, such as no more than 50 g/L, such as no more than 40 g/L, such as no more than 30 g/L, such as no more than 10 g/L, such as no more than 5 g/L, such as no more than 3 g/L. Such additives, if present at all, may be present in the cleaning composition in an amount of 0.01 g/L to 60 g/L based on total weight of the cleaning composition, such as 0.5 g/L to 50 g/L, such as 1 g/L to 40 g/L, such as 10 g/L to 30 g/L, such as g/L to 20 g/L, such as 0.01 g/L to 5 g/L, such as 0.05 g/L to 3 g/L.
[0108] The cleaning composition of the present disclosure may comprise a carrier such as water such that the cleaning composition is in the form of a solution or dispersion.
[0109] The system may further comprise a deoxidizer. As used herein, the term "deoxidizer" refers to a material or a substance that is capable of removing an oxide layer from a surface of a substrate. Deoxidizers may comprise physical deoxidizers and/or chemical deoxidizers. Suitable physical deoxidizer may uniformly roughen the substrate surface, such as by using a scouring or cleaning pad. Suitable chemical deoxidizers include, for example, acid-based deoxidizers such as phosphoric acid, nitric acid, fluoroboric acid, sulfuric acid, chromic acid, hydrofluoric acid, and ammonium bifluoride, or Amchem 7/17 deoxidizers available from Henkel Technologies (Madison Heights, MI), OAK1TE DEOXID1ZER LNC commercially available from Chemetall, TURCO DEOXIDIZER 6 commercially available from Henkel, Socosurf deoxiders commercially available from Socomore) or combinations thereof. Often, the chemical deoxidizer comprises a carrier, often an aqueous medium, so that the deoxidizer may be in the form of a solution or dispersion in the carrier.

[0110] The system of the present disclosure may further comprise a thermosetting film-forming resin or a thermoplastic film-forming resin. As used herein, the term "film-forming resin" refers to resins that can form a self-supporting continuous film on at least a horizontal surface of a substrate upon removal of any diluents or carriers present in the composition or upon curing at ambient or elevated temperatures. Conventional film-forming resins that may be used include, without limitation, those typically used in automotive OEM coating compositions, automotive refinish coating compositions, industrial coating compositions, architectural coating compositions, coil coating compositions, and aerospace coating compositions, among others. As used herein, the term "thermosetting" refers to resins that "set" irreversibly upon curing or crosslinking. wherein the polymer chains of the polymeric components are joined together by covalent bonds. This property is usually associated with a cross-linking reaction of the composition constituents often induced, for example, by heat or radiation.
Curing or cros slinking reactions also may be carried out under ambient conditions. Once cured or crosslinked, a thermosetting resin will not melt upon the application of heat and is insoluble in solvents. As used herein, the term -thermoplastic" refers to resins that comprise polymeric components that are not joined by covalent bonds and thereby can undergo liquid flow upon heating and are soluble in solvents.
[0111] In general, the colorant can be present in the coating composition in any amount sufficient to impart the desired visual and/or color effect. The colorant may comprise from 1 wt.% to 65 wt.%, such as from 3 wt.% to 40 wt.% or 5 wt.% to 35 wt.%, with weight percent based on the total weight of the composition.
[0112] In an example, the film-forming resin may be an electrodepositable coating composition comprising a water dispersible, ionic salt group-containing film-forming resin that may be deposited onto a surface of the substrate by electrodeposition.
[0113] The ionic salt group-containing film-forming polymer may comprise a cationic salt group-containing film-forming polymer for use in a cationic electrodepositable coating composition. As used herein, the term "cationic salt group-containing film-forming polymer"
refers to polymers that include at least partially neutralized cationic groups, such as sulfonium groups and ammonium groups, that impart a positive charge. The cationic salt group-containing film-forming polymer may comprise active hydrogen functional groups, including, for example, hydroxyl groups, primary or secondary amine groups, and thiol groups. Cationic salt group-containing film-forming polymers that comprise active hydrogen functional groups may be referred to as active hydrogen-containing, cationic salt group-containing film-forming polymers.
Examples of polymers that are suitable for use as the cationic salt group-containing film-forming polymer include, hut arc not limited to, alkyd polymers, acrylics, polyepoxides, polyamides, polyurethanes, polyureas, polyethers, and polyesters, among others.
[0114] The cationic salt group-containing film-forming polymer may be present in the cationic electrodepositable coating composition in an amount of 40 wt.% to 90 wt.%, such as 50 wt.% to 80 wt.%, such as 60 wt.% to 75 wt.%, based on the total weight of the resin solids of the electrodepositable coating composition. As used herein, the "resin solids"
include the ionic salt group-containing film-forming polymer, curing agent, and any additional water dispersible non-pigmented component(s) present in the electrodepositable coating composition.
[0115] Alternatively, the ionic salt group-containing film-forming polymer may comprise an anionic salt group-containing film-forming polymer for use in an anionic electrodepositable coating composition. As used herein, the term "anionic salt group-containing film-forming polymer" refers to an anionic polymer comprising at least partially neutralized anionic functional groups, such as carboxylic acid and phosphoric acid groups that impart a negative charge. The anionic salt group-containing film-forming polymer may comprise active hydrogen functional groups. Anionic salt group-containing film-forming polymers that comprise active hydrogen functional groups may be referred to as active hydrogen-containing, anionic salt group-containing film-forming polymers.
[0116] The anionic salt group-containing film-forming polymer may comprise base-solubilized, carboxylic acid group-containing film-forming polymers such as the reaction product or adduct of a drying oil or semi-drying fatty acid ester with a dicarboxylic acid or anhydride; and the reaction product of a fatty acid ester, unsaturated acid or anhydride and any additional unsaturated modifying materials which are further reacted with polyol. Also suitable are the at least partially neutralized interpolymers of hydroxy-alkyl esters of unsaturated carboxylic acids, unsaturated carboxylic acid and at least one other ethylenically unsaturated monomer. Still another suitable anionic electrodepositable resin comprises an alkyd-aminoplast vehicle, i.e., a vehicle containing an alkyd resin and an amine-aldehyde resin. Another suitable anionic electrodepositable resin composition comprises mixed esters of a resinous polyol. Other acid functional polymers may also be used such as phosphatized polyepoxide or phosphatized acrylic polymers. Exemplary phosphatized polyepoxides are disclosed in U.S.
Patent Application Publication No. 2009-0045071 at [0004]-[0015] and U.S. Patent Application Serial No. 13/232,093 at [0014]-[0040], the cited portions of which being incorporated herein by reference.
[0117] The anionic salt group-containing film-forming polymer may be present in the anionic electrodepositable coating composition in an amount 50% to 90%, such as 55% to 80%, such as 60% to 75%, based on the total weight of the resin solids of the electrodepositable coating composition.
[0118] The electrodepositable coating composition may further comprise a curing agent.
The curing agent may react with the reactive groups, such as active hydrogen groups, of the ionic salt group-containing film-forming polymer to effectuate cure of the coating composition to form a coating. Non-limiting examples of suitable curing agents are at least partially blocked polyisocyanates, aminoplast resins and phenoplast resins, such as phenolformaldehyde condensates including allyl ether derivatives thereof.
[0119] The curing agent may be present in the cationic electrodepositable coating composition in an amount of 10 wt.% to 60 wt.%, such as 20 wt.% to 50 wt.%, such as 25 wt.%
to 40 wt.%, based on the total weight of the resin solids of the electrodepositable coating composition. Alternatively, the curing agent may be present in the anionic electrodepositable coating composition in an amount of 10 wt.% to 50 wt.%, such as 20 wt.% to 45 wt.%, such as 25 wt.% to 40 wt.%, based on the total weight of the resin solids of the electrodepositable coating composition.
[0120] The electrodepositable coating composition may further comprise other optional ingredients, such as a pigment composition and, if desired, various additives such as fillers, plasticizers, antioxidants, biocides, UV light absorbers and stabilizers, hindered amine light stabilizers, defoamers, fungicides, dispersing aids, flow control agents, surfactants, wetting agents, or combinations thereof.
[0121] The electrodepositable coating composition may comprise water and/or one or more organic solvent(s). Water can, for example, be present in amounts of 40 wt.% to 90 wt.%, such as 50 wt.% to 75 wt.%, based on total weight of the electrodepositable coating composition.
If used, the organic solvents may typically be present in an amount of less than 10 wt.%, such as less than 5 wt.%, based on total weight of the electrodepositable coating composition. The electrodepositable coating composition may in particular be provided in the form of an aqueous dispersion. The total solids content of the electrodepositable coating composition may be from 1 wt.% to 50 wt.%, such as 5 wt.% to 40 wt.%, such as 5 wt.% to 20 wt.%, based on the total weight of the electrodepositable coating composition. As used herein, -total solids" refers to the non-volatile content of the electrodepositable coating composition, i.e., materials which will not volatilize when heated to 110 C for 15 minutes.
[0122]
The cationic electrodepositable coating composition may be deposited upon an electrically conductive substrate by placing the composition in contact with an electrically conductive cathode and an electrically conductive anode, with the surface to be coated being the cathode. Alternatively, the anionic electrodepositable coating composition may be deposited upon an electrically conductive substrate by placing the composition in contact with an electrically conductive cathode and an electrically conductive anode, with the surface to be coated being the anode. An adherent film of the electrodepositable coating composition may be deposited in a substantially continuous manner on the cathode or anode when a sufficient voltage is impressed between the electrodes. The applied voltage may be varied and can be, for example, as low as one volt to as high as several thousand volts, such as between 50 and 500 volts. Current density is usually between 1.0 ampere and 15 amperes per square foot (10.8 to 161.5 amperes per square meter) and tends to decrease quickly during the electrodeposition process, indicating formation of a continuous self-insulating film.
[0123]
The film-forming resin may comprise a powder coating composition. As used herein, "powder coating composition refers to a coating composition which is completely free of water and/or solvent. Accordingly, the powder coating composition disclosed herein is not synonymous to waterborne and/or solvent-borne coating compositions known in the art. The powder coating composition may comprise: (a) a film-forming polymer having a reactive functional group; and (b) a curing agent that is reactive with the functional group. Examples of powder coating compositions that may be used in the present disclosure include the polyester-based ENV1ROCRON line of powder coating compositions commercially available from PPG
Industries, Inc. or epoxy-polyester hybrid powder coating compositions.
Alternative examples of powder coating compositions that may be used in the present disclosure include low temperature cure thermosetting powder coating compositions comprising (a) at least one tertiary aminourea compound, at least one tertiary aminourethane compound, or mixtures thereof, and (b) at least one film-forming epoxy-containing resin and/or at least one siloxane-containing resin (such as those described in U.S. Patent No. 7,470,752, assigned to PPG Industries Ohio, Inc. and incorporated herein by reference); curable powder coating compositions generally comprising (a) at least one tertiary aminourea compound, at least one tertiary aminourethane compound, or mixtures thereof, and (b) at least one film-forming epoxy-containing resin and/or at least one siloxane-containing resin (such as those described in U.S. Patent No.
7,432,333, assigned to PPG
Industries Ohio, Inc. and incorporated herein by reference); and those comprising a solid particulate mixture of a reactive group-containing polymer having a Tg of at least 30 C (such as those described in U.S. Patent No. 6,797,387, assigned to PPG Industries Ohio, Inc. and incorporated herein by reference).
[0124] The film-forming resin may comprise a liquid coating composition. As used herein, "liquid coating composition" refers to a coating composition which contains a portion of water and/or solvent. Accordingly, the liquid coating composition disclosed herein is synonymous with waterborne and/or solvent-borne coating compositions known in the art. The liquid coating composition may comprise, for example, (a) a film-forming polymer having a reactive functional group and (b) a curing agent that is reactive with the functional group. In other examples, the liquid coating may contain a film-forming polymer that may react with oxygen in the air or coalesce into a film with the evaporation of water and/or solvents. These film-forming mechanisms may require or be accelerated by the application of heat or some type of radiation such as Ultraviolet or Infrared. Examples of liquid coating compositions that may be used in the present disclosure include the SPECTRACRONO line of solvent-based coating compositions, the AQUACRONO line of water-based coating compositions, and the RAYCRONO line of UV cured coatings all commercially available from PPG
Industries, Inc.
[0125] Suitable film-forming polymers that may be used in the liquid coating composition of the present disclosure may comprise a (poly)ester, an alkyd, a (poly)urethane, an isocyanurate, a (poly)urea. a (poly)epoxy, an anhydride, an acrylic, a (poly)ether, a (poly)sulfide, a (poly)amine, a (poly)amide, (poly)vinyl chloride, (poly)olefin, (poly)vinylidene fluoride, (poly)siloxane, or combinations thereof.
[0126] The film-forming polymer composition may comprise a primer composition. The primer compositions may comprise, for example, chromate-based primer compositions such as those available from PPG Industries, Inc. (product code 44GN072), or a chrome-free primer composition such as those available from PPG (DESOPRIME CA7502, DESOPRIME
CA7521, Deft 02GN083, Deft 02GN084) or such as those described in U.S. Patent Application Serial No.
10/758,973, titled "Corrosion Resistant Coatings Containing Carbon", and U.S.
Patent Application Serial Nos. 10/758,972 and 10/758,972, both titled -Corrosion Resistant Coatings", all of which are incorporated herein by reference. In examples, the primer composition may be one which can pass the military requirement of MIL-PRF-85582 Class N or MIL-Class N.
[0127] The film-forming polymer composition may comprise a topcoat composition. As used herein, the term "topcoat composition" refers to a mixture of binder(s) (i.e., organic or inorganic based polymer(s)) and at least one pigment, which can optionally contain at least one solvent and/or at least one curing agent. Topcoat compositions form a topcoat on a substrate, which is typically the coating layer in a single or multi-layer coating system whose outer surface is exposed to the atmosphere or environment, and whose inner surface is in contact with another coating layer or polymeric substrate. Examples of suitable topcoat compositions include those conforming to MIL-PRF-85285D, such as those available from PPG (Deft 03W127A
and Deft 03GY292). Other suitable topcoat compositions include advanced performance topcoat compositions such as those available from PPG (Defthanee ELT.TM. 99GY001 and 99W009).
However, other topcoat compositions and advanced performance topcoat compositions can be used in the present disclosure as will be understood by those of skill in the art with reference to this disclosure.
[0128] The film-forming polymer composition may comprise a self-priming topcoat or an enhanced self-priming topcoat. Examples of suitable self-priming topcoat compositions include those that conform to TT-P-2756A. Examples of self-priming topcoat compositions include those available from PPG (03W169 and 03GY369), and examples of enhanced self-priming topcoat compositions include Defthanee ELTIm/ESPT (product code 97GY121), available from PPG. However, other self-priming topcoats and enhanced self-priming topcoats can be used in the coating system according to the present disclosure as will be understood by those of skill in the art with reference to this disclosure.
[0129] In addition to the components described above, such film-forming resins may further comprise colorants, surfactants, wetting agents and/or catalysts. As used herein, the term "colorant" means any substance that is capable of imparting color, opacity and/or other visual effect to the composition. Example colorants include pigments, dyes and tints, such as those used in the paint industry and/or listed in the Dry Color Manufacturers Association (DCMA).
Methods [0130] Also disclosed herein arc methods for treating a substrate. The method may comprise, or consist essentially of, or consist of, contacting at least a portion of a surface of a substrate with one of the conversion compositions described herein above.
[0131] The solution or dispersion of the conversion composition may be brought into contact with the substrate by any of a variety of known techniques, such as dipping or immersion, spraying, intermittent spraying, dipping followed by spraying, spraying followed by dipping, brushing, or roll-coating. The solution or dispersion, when applied to the metal substrate, may be at a temperature ranging from 40 F to 160 F, such as 60 F to 110 F, such as 70 F to 90 F. For example, the process may be carried out at ambient or room temperature. The contact time is often from 1 second to 30 minutes, such as 30 seconds to 15 minutes, such as 4 minutes to 10 minutes.
[0132] Following the contacting with the conversion composition, the substrate optionally may be air dried at room temperature or may be dried with hot air, for example, by using an air knife, by flashing off the water by brief exposure of the substrate to a high temperature, such as by drying the substrate in an oven at 15 C to 100 C, such as 20 C to 90 C, or in a heater assembly using, for example, infrared heat, such as for 10 minutes at 70 C, or by passing the substrate between squeegee rolls. Alternatively, following the contacting with the conversion composition, the substrate optionally may be rinsed with tap water, deionized water, reverse osmosis (RO) water and/or an aqueous solution of rinsing agents in order to remove any residue and then optionally may be dried, for example air dried or dried with hot air as described in the preceding sentence.
[0133] The metal substrate optionally may be prepared by first solvent treating the metal substrate prior to contacting the metal substrate with a cleaning composition, a deoxidizing composition, or one of the conversion compositions described herein. As used herein, the term "solvent treating" refers to rinsing, wiping, spraying, or immersing the substrate in a solvent that assists in the removal of inks, oils, etc., that may be on the metal surface.
Nonlimiting examples of suitable solvents include methyl ethyl ketone (MEK), methyl propyl ketone (MPK), acetone, and the like. Alternately, the metal substrate may be prepared by degreasing the metal substrate using conventional degreasing methods prior to contacting the metal substrate with the cleaning composition.
[0134] Additional optional procedures for preparing the metal substrate include the use of a surface brightener, such as an acid pickle or light acid etch, or a smut remover.
[0135] Optionally, at least a portion of the substrate surface may be cleaned and/or deoxidized prior to contacting at least a portion of the substrate surface with conversion compositions described above, in order to remove grease, dirt, and/or other extraneous matter, using any of the cleaners and/or deoxidizers described above. Such cleaners and/or deoxidizers are often preceded or followed by a water rinse, such as with tap water, distilled water, RO
water, or combinations thereof. For example, the methods of the present disclosure may include cleaning compositions and deoxidizing compositions which are applied to the substrate surface in sequential steps, optionally with a rinse step(s) intervening.
[0136] Optionally, as mentioned above, optionally, at least a portion of the cleaned substrate surface may be deoxidized, mechanically and/or chemically. Often, the chemical deoxidizer comprises a carrier, often an aqueous medium, so that the deoxidizer may be in the form of a solution or dispersion in the carrier, in which case the solution or dispersion may be brought into contact with the substrate by any of a variety of known techniques, such as dipping or immersion, spraying, intermittent spraying, dipping followed by spraying, spraying followed by dipping, brushing, or roll-coating. The skilled artisan will select a temperature range of the solution or dispersion, when applied to the metal substrate, based on etch rates, for example, at a temperature ranging from 50 F to 150 F (10 C to 66 C), such as from 70 F to 130 F (21 C to 54 C), such as from 80 F to 120 F (27 C to 49 C). The contact time may be from 30 seconds to 20 minutes, such as 1 minute to 15 minutes, such as 90 seconds to 12 minutes, such as 3 minutes to 9 minutes.
[0137] The cleaning and deoxidizing compositions may be brought into contact with the substrate surface by any of a variety of techniques. including, but not limited to, dip immersion, spraying, swabbing, or spreading using a brush, roller, or the like. With regard to application via spraying, conventional (automatic or manual) spray techniques and equipment used for air spraying may be used. The dwell time in which the cleaning composition remains in contact with the metal substrate may vary from a few seconds to several hours, for example less than 30 minutes or 3 minutes or less.

[0138] After contacting the metal substrate with the cleaning composition, the metal substrate may optionally be air dried, and then rinsed with tap water, RO
water, and/or distilled/de-ionized water. Alternately, after contacting the metal substrate with the composition, the metal substrate may be rinsed with tap water, RU water, and/or distilled/de-ionized water, and then subsequently air dried (if desired). However, the substrate need not be dried; and in some instances, drying is omitted. Additionally, as noted above, the substrate need not be rinsed, and the metal substrate may then be further coated with conversion coatings, primers and/or topcoats to achieve a substrate with a finished coating. Accordingly, in some instances, this subsequent rinse may be omitted. For example, a solvent (e.g., alcohol) may be used to rinse the substrate, which allows the omission of a drying step.
[0139] After the substrate is contacted with the conversion composition, a coating composition comprising a film-forming resin may be deposited onto at least a portion of the surface of the substrate that has been contacted with the conversion composition. Any suitable technique may be used to deposit such a coating composition onto the substrate, including, for example, brushing, dipping, flow coating, spraying and the like. In some instances, however, as described in more detail below, such depositing of a coating composition may comprise an electrocoating step wherein an electrodepositable composition is deposited onto a metal substrate by electrodeposition. In certain other instances, as described in more detail below, such depositing of a coating composition comprises a powder coating step. In still other instances, the coating composition may be a liquid coating composition.
[0140] Once the cationic or anionic electrodepositable coating composition is electrodeposited over at least a portion of the electroconductive substrate, the coated substrate may be heated to a temperature and for a time sufficient to cure the electrodeposited coating on the substrate. For cationic electrodeposition, the coated substrate may be heated to a temperature ranging from 250 F to 450 F (121.1 C to 232.2 C), such as from 275 F to 400 F
(135 C to 204.4 C), such as from 300 F to 360 F (149 C to 180 C). For anionic electrodeposition, the coated substrate may be heated to a temperature ranging from 200 F to 450 F
(93 C to 232.2 C), such as from 275 F to 400 F (135 C to 204.4 C), such as from 300 F to 360 F
(149 C to 180 C), such as 200 F to 210.2 F (93 C to 99 C). The curing time may be dependent upon the curing temperature as well as other variables, for example, the film thickness of the electrodeposited coating, level and type of catalyst present in the composition and the like. For example, the curing time can range from 10 to 60 minutes, such as 20 to 40 minutes. The thickness of the resultant cured electrodeposited coating may range from 2 to 50 microns.
[0141] After deposition of the powder coating composition, the coating is often heated to cure the deposited composition. The heating or curing operation is often carried out at a temperature in the range of from 150 C to 200 C, such as from 170 C to 190 C, for a period of time ranging from 10 to 20 minutes. The thickness of the resultant film is from 50 to 125 microns.
[0142] The self-priming topcoat and enhanced self-priming topcoat may be applied directly to the substrate treated with the conversion composition. The self-priming topcoat and enhanced self-priming topcoat can optionally be applied to an organic or inorganic polymeric coating, such as a primer or paint film. The self-priming topcoat layer and enhanced self-priming topcoat is typically the coating layer in a single or multi-layer coating system where the outer surface of the coating is exposed to the atmosphere or environment, and the inner surface of the coating is typically in contact with the substrate or optional polymer coating or primer.
[0143] The topcoat, self-priming topcoat, and enhanced self-priming topcoat can be applied to the treated substrate, in either a wet or "not fully cured"
condition that dries or cures over time, that is, solvent evaporates and/or there is a chemical reaction.
The coatings can dry or cure either naturally or by accelerated means, for example, an ultraviolet light cured system to form a film or "cured" paint. The coatings can also be applied in a semi or fully cured state, such as an adhesive.
Substrates [0144] Disclosed herein are substrates treated with the conversion compositions described above. Also disclosed herein are substrates treated with the systems and methods described above.
[0145] Suitable substrates that may be used in the present disclosure include metal substrates, metal alloy substrates, and/or substrates that have been metallized, such as nickel-plated plastic. The metal or metal alloy can comprise or be steel, aluminum, zinc, nickel, and/or magnesium. For example, the steel substrate could be cold rolled steel, hot rolled steel, electrogalvanized steel, and/or hot dipped galvanized steel. Aluminum alloys of the 1XXX, 2XXX, 3XXX, 4XXX, 5XXX, 6XXX, or 7XXX series as well as clad aluminum alloys also may be used as the substrate. Aluminum alloys may comprise 0.01 wt.% copper to 10 wt.% copper.

Aluminum alloys which are treated may also include castings, such as 1XX.X, 2XX.X, 3XX.X, 4XX.X, 5XX.X, 6XX.X, 7XX.X. 8XX.X, or 9XX.X (e.g., A356.0). Magnesium alloys of the AZ31B, AZ91C, AM60B, or EV31A series also may be used as the substrate. The substrate used in the present disclosure may also comprise titanium and/or titanium alloys, zinc and/or zinc alloys, and/or nickel and/or nickel alloys. The substrate also may comprise assemblies or multi-metal substrates. The substrate may comprise a portion of a vehicle such as a vehicular body (e.g., without limitation, door, body panel, trunk deck lid, roof panel, hood, roof and/or stringers, rivets, landing gear components, and/or skins used on an aircraft) and/or a vehicular frame. As used herein. "vehicle" or variations thereof include, but is not limited to, civilian, commercial, and military aircraft, and/or land vehicles such as cars, motorcycles, and/or trucks.
[0146] In examples, the substrate may be a complex part and/or may have a non-horizontal surface. The surface may be a substantially vertical surface.
[0147] Disclosed herein are treated substrates. The treated substrates may comprise, or consist essentially of, or consist of, a film formed from one of the conversion compositions disclosed herein. The film may be formed from a conversion composition comprising, or consisting essentially of, or consisting of, a yield stress component and a corrosion inhibitor, wherein the conversion composition comprises a yield stress sufficient to overcome the effect of gravity when applied to a non-horizontal surface.
[0148] Also disclosed herein are substrates treated with any of the systems disclosed hereinabove. The substrate may be treated with a system comprising, or consisting essentially of, or consisting of: one of the conversion compositions disclosed hereinabove; and at least one of a cleaning composition, a deoxidizer, a film-forming resin or combinations thereof.
[0149] Also disclosed herein are substrates treated with any of the methods disclosed hereinabove. The substrate may be treated with a method comprising, or consisting essentially of, or consisting of: contacting at least a portion of a surface of the substrate with one of the conversion composition disclosed hereinabove; and optionally contacting at least a portion of the surface with a cleaning composition and/or a deoxidizer disclosed hereinabove.
[0150] It has been surprisingly discovered that the conversion compositions disclosed herein provide substrates with corrosion protection when exposed to neutral salt spray testing for 24 hours. For example, the substrate surface may comprise less than 1%
corrosion over a 1.376 in2 area of the substrate surface following 24-hour exposure to a 5% sodium chloride salt fog environment (salt spray cabinet operated according to ASTM B117 (2019)), such as less than 0.75% corrosion, such as less than 0.5% corrosion, such as less than 0.25%
corrosion, such as less than 0.2% corrosion. For example, the treated substrate may pass corrosion testing according to ASTM D610-08 (2019) rating scale, such as a rating of at least 7P, such as at least 8P, such as at least 9P.
Uses [0151] Also disclosed are uses of the compositions disclosed herein to provide a conversion composition comprising (i) a yield stress sufficient to overcome the effect of gravity when applied to a non-horizontal surface and (ii) a shear thinning rheology profile.
[0152] Also disclosed are uses of a film formed on a substrate surface from the conversion compositions disclosed herein to provide a film that overcomes the effect of gravity when applied to a non-horizontal surface and that provides corrosion protection to the surface such that the substrate surface comprises less than 1% corrosion of a 1.376 in2 area of the substrate surface following 24 hour exposure to a 5% sodium chloride salt fog environment (salt spray cabinet operated according to ASTM B117 (2019)) and/or wherein the substrate passes corrosion testing according to ASTM D610-08 (2019) rating scale. The substrate may comprise a substantially vertical surface. The substrate may comprise a complex substrate.
[0153] The films formed by the conversion compositions, systems and methods may be used to repair a surface of a substrate.
Methods of Making the Conversion Compositions [0154] The conversion compositions disclosed herein may be made by first optionally adjusting a pH of the yield stress component to a pH of less than 7; and then mixing the yield stress component with the corrosion inhibitor. Optionally, the pH of the conversion composition may be adjusted to a pH less than 7, such as a pH of 2.8 to 4.5.
[0155] Optionally, the yield stress fluid may be made using conventional free-radical polymerization techniques including emulsion, dispersion or solution processes.
[0156] Illustrating the disclosed subject matter are the following examples that are not to be considered as limiting the disclosure to their details. All parts and percentages in the examples, as well as throughout the specification, are by weight unless otherwise indicated.

EXAMPLES
Preparation of corrosion inhibitor compositions [0157] A 1.0 wt% solution of diutan gum in deionized water was prepared by adding 5.0g of diutan gum to 495g of warmed, deionized water and stirring for 18 hours to obtain a homogeneous solution.
[0158] A concentrated solution of corrosion inhibitor was prepared in the following manner. Potassium hexafluorozirconate (1.5g) was added to 500g of deionized distilled water and stirred until completely dissolved. Chromium(III) chloride hexahydrate (2.2g) was then added and the mixture stirred to obtain a homogeneous solution.
[0159] The concentrated solution of corrosion inhibitor was then combined with the solution of diutan gum and diluted to the final concentrations shown in Table 2 to form the compositions of Samples A to E, with Sample E being a comparative example.
[0160] Additional comparative Samples F and G were prepared using MethocelT" A4M
as shown in Table 2. The concentrated solution of corrosion inhibitor was combined with deionized water and dry McthocclTM A4M powder, then stirred at high speed for six hours, to obtain a homogenous solution.
Table 2. Corrosion inhibitor compositions Sample Diutan MethocelTM A4M Chromium(III) Potassium gum (wt%) (wt%) chloride hexafluorozirconate hexahydrate (g/L) (g/L) A 0.20 0.0 2.2 1.5 0.30 0.0 2.2 1.5 0.40 0.0 2.2 1.5 0.50 0.0 2.2 1.5 0.10 0.0 2.2 1.5 (comparative) 0.0 0.20 2.2 1.5 (comparative) 0.0 2.0 2.2 1.5 (comparative) Rheology measurements [0161] Dynamic and steady state rheology measurements on samples A to G were performed at 25 C on a Discovery HR-2 rheometer from TA Instruments with concentric cylinder geometry.
[0162] The elastic (G') and viscous (G") moduli were determined as a function of increasing stress amplitude at a frequency of 1 Hz and the crossover of G' and G" was used to estimate the yield stress. Data are reported in Table 3 below.
Table 3. Yield Stress Sample Yield Stress (Pa) A 1.62 3.07 5.96 10.1 E (comparative) 0.536 F (comparative) Not detected G (comparative) Not detected [0163] Steady shear viscosities were measured in the shear rate range of 1 to 1000 s-1.
Data are reported in Table 4 below.
Table 4. Viscosity Measurements Shear Rate (s-1) Viscosity sample Viscosity sample Viscosity Sample A (mPa.$) E (naPa.$) G (naPa.$) 1 2.57x103 625 2.20x103 395 114 1.62x103 100 51.2 19.5 771 1000 10.6 8.10 230 [0164] Both samples A and E exhibited shear thinning (decrease in viscosity with increasing shear rate) with sufficiently low viscosity at the higher shear rates to enable easy application but sample A exhibited much stronger shear thinning and a higher yield stress.

Sample G showed shear thinning that was much weaker than sample A resulting in a relatively high viscosity at high shear rates that is not desirable for application.
Sample Application and 24 Hours Corrosion Testing [0165] FIG. 1 shows schematics of photographs taken of panels 100 treated as follows.
Panels 100 are shown in holders 200 which held the panels at a substantially vertical orientation.
[0166] Samples A to G were applied on 2024-T3 bare aluminum panels (3 inches wide, inches long and 0.032 inches thick) using the following procedure. The panels were first subjected to a tap water abrade that consisted of wetting the substrate with tap water, scrubbing the surface with a Scotch-Brite 7447 pad, spray rinsing with tap water, wiping down the rinsed surface with a cheesecloth to remove residual smut followed by a final tap rinse. The panels were then dried in air prior to application of the conversion coatings. The panels were secured on a rack in a substantially vertical orientation at an inclination of 70-90 degrees above the horizontal. One of the conversion compositions was applied by brushing once in an upward direction, starting at the bottom of the panel, to wet the surface and allowing the formula to dwell in place for a total of 5 minutes. A wet gauze wipe was performed on the treated panels by wiping three times with a clean cheesecloth that had been saturated with deionized water.
[0167] As shown in FIG. 1E, 1F and 1G, Samples E, F and G
(comparatives) did not have sufficient yield stress for the composition to cling to the substrate without dripping when the substrate was oriented substantially vertically during application.
However, as shown in FIG.
1A, 1B, 1C, and 1D, Samples A, B, C and D had sufficient yield stress to counteract the effect of gravity on the wet coated film (i.e., to cling to the substrate surface) and little to no dripping was observed in these Samples.
[0168] Five panels prepared with Sample A were then dried in air again and exposed to neutral salt spray (5% sodium chloride salt fog environment) for 24 hours.
Five untreated panels H were prepared the same way as those treated with Sample A, but without any conversion coating (i.e., subjected to a tap water abrade, scrubbing, rinsing and wiping as described above but not treated with any of Samples A to G) were run as control H.
[0169] After salt spray exposure, panels were rinsed and dried.
FIG. 2A shows photographs of panels treated with Sample A following exposure to neutral salt spray according to the Example disclosed herein and FIG. 2B shows photographs of untreated panels (H) following exposure to neutral salt spray. As shown, panels treated with Sample A had virtually no corrosion on the substrate surface (FIG. 2A), while the substrate surface of the untreated panel H was significantly corroded as shown by the significant number of pits (see arrow as an example) and corrosion products formed on the substrate surface (FIG. 2B).
[0170] Panels were analyzed for corrosion with a VHX-2000 super resolution digital microscope from Keyence equipped with a VH-ZOOR lens. A magnified image of a 1.376 in2 region in the center of the panel was taken using the auto area measurement tool in the "mesr/draw" menu. Extraction parameters were set so that the area of the panel that had corroded was highlighted, and the total highlighted area measured as a fraction of the total analysis area and reported below as a percent value. Three sections of each panel were measured and then averaged. Data are presented in Table 5 below. Corrosion on panels also was rated according to "Table 1 Scale and Description of Rust Ratings" from the specification ASTM
D610-08 (2019), and the ratings are shown in Table 5 below.
Table 5. Corrosion data following Exposure to ASTM B117 (2019) Neutral Salt Spray Corrosion Results After 24 Hours Neutral Salt Spray Sample A CONTROL H
Panel Set Corrosion ASTM D610 Corrosion Area (%) Rating Area (%) Rating 1 0.139 7P 69.116 2 0.049 8P 75.548 3 0.186 7P 72.853 4 0.132 7P 69.128 0.123 7P 71.212 0 Average 0.126 7P 71.571 [0171] Sample A provided significant improvement in corrosion protection. The control panels without the conversion coating averaged >70% corroded area per panel and failed testing according to ASTM D610 rating scale, whereas panels with Sample A had no more than 0.2%
corroded area and passed according to the ASTM D610 rating scale.
[0172] Collectively, the data presented herein demonstrate that Samples containing more than 0.10% diutan gum and trivalent chromium not only provide corrosion protection to treated substrates, but also combines the advantages of low viscosity at high shear rates for easy brush application with a high enough yield stress to prevent the wet coating from dripping when applied to vertically oriented surfaces.

[0173] Whereas particular features of the present disclosure have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the coating composition, coating, and methods disclosed herein may be made without departing from the scope in the appended claims.

Claims (54)

We claim:

1. A conversion composition comprising:
a yield stress component; and a corrosion inhibitor;
wherein the conversion composition comprises a yield stress sufficient to overcome the effect of gravity when applied to a non-horizontal surface.

2. The conversion composition of claim 1, wherein the conversion composition comprises the yield stress component dissolved or dispersed in a fluid medium, such as an aqueous medium.

3. The conversion composition of claim 1 or claim 2, wherein the conversion composition comprises a yield stress of at least 0.6 Pa at a frequency of 1 Hz and a temperature of 25 C when the composition is applied to a substantially vertical substrate surface at a thickness of 0.5 mil to 40 mil, such as at least 0.7 Pa, such as at least 0.8 Pa, such as at least 0.9 Pa, such as at least 1.0 Pa, such as at least 2.0 Pa, such as at least 3.0 Pa, such as at least 4.0 Pa, such as at least 5.0 Pa, such as at least 6.0 Pa, such as at least 7.0 Pa, such as at least 8.0 Pa, such as at least 9.0 Pa, such as at least 10.0 Pa.

4. The conversion composition of any of the preceding claims, wherein the conversion composition comprises a yield stress of no more than 50.0 Pa at a frequency of 1 Hz and a temperature of 25 C when the composition is applied at a thickness of 0.5 mil to 40 mil to a substantially vertical substrate surface, such as no more than 40.0 Pa, such as no more than 30.0 Pa, such as no more than 20.0 Pa, such as no more than 20.0 Pa.

5. rlhe conversion composition of any of the preceding claims, wherein the conversion composition comprises a yield stress of 0.6 Pa to 50.0 Pa at a frequency of 1 Hz and a temperature of 25 C when the composition is applied at a thickness of 0.5 mil to 40 mil to a substantially vertical substrate surface, such as 0.7 Pa to 50.0 Pa, such as 0.8 Pa to 50.0 Pa, such as 0.9 Pa to 50.0, such as 1.0 Pa to 40.0 Pa, such as 2.0 Pa to 40.0 Pa, such as 3.0 Pa to 30.0 Pa, such as 4.0 Pa to 20.0 Pa, such as 5.0 Pa to 20.0 Pa, such as 6.0 Pa to 20.0 Pa, such as 7.0 Pa to 20.0 Pa, such as 8.0 Pa to 20.0 Pa, such as 9.0 Pa to 20.0 Pa, such as 10.0 Pa to 20.0 Pa.

6. The conversion composition of any of the preceding claims, wherein the conversion composition comprises a viscosity of less than 700 mPa.s. at a shear rate of 100 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 600 mPa.s.
at a shear rate of 100 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 500 mPa.s. at a shear rate of 100 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 400 mPa.s. at a shear rate of 100 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 300 mPa.s. at a shear rate of 100 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 200 mPa.s. at a shear rate of 100 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 100 mPa.s. at a shear rate of 100 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 75 mPa.s. at a shear rate of 100 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 70 mPa.s.
at a shear rate of 100 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 60 mPa.s. at a shear rate of 100 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 55 mPa.s.
at a shear rate of 100 reciprocal seconds at a temperature of 25 C.

7. The conversion composition of any of the preceding claims, wherein the conversion composition comprises a viscosity of less than 200 mPa.s. at a shear rate of 1000 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 175 mPa.s.
at a shear rate of 1000 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 150 mPa.s. at a shear rate of 1000 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 125 mPa.s. at a shear rate of 1000 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 100 mPa.s. at a shear rate of 1000 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 80 mPa.s. at a shear rate of 1000 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 60 mPa.s. at a shear rate of 1000 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 50 mPa.s.
at a shear rate of 1000 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 40 mPa.s. at a shear rate of 1000 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 30 mPa.s. at a shear rate of 1000 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 20 mPa.s. at a shear rate of 1000 reciprocal seconds at a temperature of 25 C, such as a viscosity of less than 15 mPa.s. at a shear rate of 1000 reciprocal seconds at a temperature of 25 C.

8. The conversion composition of any of the preceding claims, wherein the yield stress component comprises a pKa of at least 3, such as at least 3.2, such as no more than 7, such as no more than 4, such as no more than 3.7, such as 3 to 7, such as 3 to 4, such as 3.2 to 3.7.

9. The conversion composition of any of the preceding claims, wherein the yield stress component comprises a crosslinked microgel polymer and/or a network-forming polymer.

10. The conversion composition of claim 9, wherein the crosslinked microgel polymer comprises a polyelectrolyte microgel polymer, a crosslinked nonionic microgel polymer or combinations thereof.

11. The conversion composition of claim 9 or claim 10, wherein the crosslinked microgel polymer comprises a pl-l-activated crosslinked microgel polymer and/or an acidic moiety.

12. The conversion composition of any of claims 9 to 11, wherein the crosslinked microgel polymer comprises a carboxylic acid polymer and/or a crosslinked alkali swellable polymer.

13. The conversion composition of any of claims 9 to 12, wherein the crosslinked microgel polymer comprises maleic acid, itaconic acid and/or (meth)acrylic acid, and/or the alkali swellable polymer comprises an alkyl acrylic, a (meth)acrylic acid, a carboxylic acid and/or a non-acid vinyl.

14. The conversion composition of any of claims 9 to 13, wherein the crosslinked microgel polymer comprises a hydrophobically modified polymer.

15. The conversion composition of any of claims 9 to 14, wherein the crosslinked microgel polymer comprises an amphiphilic crosslinked nonionic polymer and/or is activatable by a surfactant.

16. The conversion composition of any of claims 9 to 15, wherein the network-forming polymer comprises a biopolymer.

17. The conversion composition of any of claims 9 to 16, wherein the network-forming polymer comprises an ionic biopolymer such as a polyvalent ion and/or an anionic polysaccharide, a neutral biopolymer such as a neutral polysaccharide, or combinations thereof.

18. The conversion composition of claim 16 or claim 17, wherein the biopolymer comprises xanthan gum, welan gum, diutan gum, scleroglucan or combinations thereof.

19. The conversion composition of any of claims 16 to 18, wherein the biopolymer comprises no more than 4 charged groups per monosaccharide unit, such as no more than 3 charged groups per monosaccharide unit, such as no more than 2 charged groups per monosaccharide unit, such as no more than 1 charged group per monosaccharide unit.

20. The conversion composition of any of claims 16 to 19, wherein the biopolymer comprises at least 1 shielded charged group, such as by a hydrophilic side group.

21. The conversion composition of any of the preceding claims, wherein the conversion composition comprises the yield stress component in an amount of at least 0.2 percent by weight based on total weight of the composition, such as at least such as at least 0.3 percent by weight based on total weight of the composition, such as at least 0.4 percent by weight based on total weight of the composition, such as at least 0.5 percent by weight based on total weight of the composition, such as at least 0.6 percent by weight based on total weight of the composition, such as at least 0.7 percent by weight based on total weight of the composition, such as at least 0.8 percent by weight based on total weight of the conlposition, such as at least 0.9 percent by weight based on total weight of the composition, such as at least 1.0 percent by weight based on total weight of the composition, such as at least 1.5 percent by weight based on total weight of the composition, such as at least 2.0 percent by weight based on total weight of the composition.

22. The conversion composition of any of the preceding claims, wherein the conversion composition comprises the yield stress component in an amount such that the conversion composition comprises yield stress and shear thinning properties described above while not negatively corrosion performance and coating behaviors such as leveling, ease of application and the like.

23. The conversion composition of any of the preceding claims, wherein the corrosion inhibitor comprises a trivalent chromium.

24. The conversion composition of claim 23, wherein the conversion composition comprises the trivalent chromium in an amount of at least 0.005 g/L based on total weight of the conversion composition, such as at least 0.01 g/L, such as at least 0.5 g/L.

25. The conversion composition of claim 23 or claim 24, wherein the conversion composition comprises the trivalent chromium in an amount of no more than 2 g/L based on total weight of the conversion composition, such as no more than 1.5 g/L, such as no more than 1 g/L.

26. The conversion composition of any of claims 23 to 25, wherein the conversion composition comprises the trivalent chromium in an amount of 0.005 g/L to 2 g/L based on total weight of the conversion composition, such as 0.01 g/L to 1.5 g/L, such as 0.5 g/L to 1 g/L.

27. The conversion composition of any of the preceding claims, wherein the conversion composition further comprises a halogen, a sulfate, a nitrate, an acetate, a carbonate, a hydroxide or combinations thereof.

28. The conversion composition of any of claims 23 to 27, wherein the trivalent chromium comprises a trivalent chrome halide, basic chrome sulfate, potassium chrome sulfate, chrome sulfate or combinations thereof.

29. The conversion composition of any of the preceding claims, wherein the conversion composition further comprises a second corrosion inhibitor and/or a conjugated compound.

30. The conversion composition of claim 29, wherein the second coinhibitor comprises a transition metal, such as a Group IVB metal.

31. The conversion composition of claim 29 or claim 30, wherein the conversion composition comprises the coinhibitor in an amount of at least 0.05 g/L based on total weight of the conversion composition, such as at least 0.07 g/L, such as at least 0.5 g/L.

32. The conversion composition of any of claims 29 to 31, wherein the conversion composition comprises the coinhibitor in an amount of no more than 5 g/L based on total weight of the conversion composition, such as no more than 4 g/L, such as no more than 1 g/L.

33. The conversion composition of any of claims 29 to 32, wherein the conversion composition comprises the coinhibitor in an amount of 0.05 g/L to 5 g/L based on total weight of the conversion composition, such as 0.07 g/L to 4 g/L, such as 0.5 g/L to 1 g/L.

34. The conversion composition of any of the preceding claims, wherein the conversion composition is substantially free, or essentially free, or completely free, of a Group IIB metal compound and/or hexavalent chromium.

35. The conversion composition of any of the preceding claims, wherein the conversion composition comprises a pH of less than 7, such as less than 5, such as 1.5 to 6.9, such as 2.0 to 6.0, such as 2.5 to 4.5, such as 2.8 to 4.5.

36. A system for treating a metal substrate comprising:
the conversion composition of any of the preceding claims; and at least one of a cleaning composition, a deoxidizer, a film-forming resin or combinations thereof.

37. The system of claim 36, wherein the cleaning composition comprises a hydroxide, a phosphate, an azole or combinations thereof.

38. A method of treating a metal substrate, comprising:
contacting at least a portion of a surface of the substrate with the conversion composition of any of claims 1 to 35.

39. A substrate comprising a film formed from the conversion composition of any of claims 1 to 35.

40. A substrate treated with the system of claim 36 or claim 37.

41. A substrate treated according to the method of claim 38.

42. The substrate of any of claims 39 to 41, wherein the film comprises a wet film thickness of 0.5 mil to 40 mil.

43. The substrate of any of claims 39 to 42, wherein less than 1% of a 1.376 i112area of the substrate surface comprises corrosion following 24-hour exposure to a 5%
sodium chloride salt fog environment and/or wherein the substrate passes corrosion testing according to ASTM D610-08 (2019) rating scale.

44. The substrate of any of claims 39 to 43, wherein the substrate comprises a non-horizontal surface.

45. The substrate of any of claims 39 to 44, wherein the substrate comprises a substantially vertical surface.

46. The substrate of any of claims 39 to 45, wherein the substrate comprises a complex substrate.

47. A use of the conversion composition of any of claims 1 to 35 to provide a composition comprising (i) a yield stress sufficient to overcome the effect of gravity when applied to a non-horizontal surface and (ii) a shear thinning rhcology profile.

48. A use of a film formed on a surface of a substrate from the conversion composition of any of claims 1 to 35 to provide a film that overcomes the effect of gravity when applied to a non-horizontal surface and that provides corrosion protection to the surface such that the substrate surface comprises less than 1% corrosion of a 1.376 in2 area of the substrate surface following 24 hour exposure in a neutral salt spray cabinet operated according to ASTM B117 (2019) and/or wherein the substrate passes corrosion testing according to ASTM
D610-08 (2019) rating scale.

49. The use of claim 48, wherein the surface comprises a non-horizontal surface.

50. The use of claim 48 or claim 49, wherein the surface comprises a substantially vertical surface.

51. The use of any of clanns 48 to 50, wherein the substrate comprises a complex substrate.

52. The use of any of claims 47 to 51, wherein the use comprises a repair of the surface.

53. The substrate of any of claims 36 to 52, wherein the substrate comprises aluminum, an aluminum alloy or combinations thereof.

54. rlhe substrate of claim 53. wherein the aluminum alloy comprises copper.