AU2022376938B2 - Compositions, systems and methods for treating a substrate - Google Patents

Description

PCT/US2022/078770

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 are 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. 1A (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.

PCT/US2022/078770

[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 vt.%, 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, IB, and IIB 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

PCT/US2022/078770

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 element 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 IIIB 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 IVB 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, 63rd edition (1983), corresponding to Group 4 in the actual

IUPAC numbering.

PCT/US2022/078770

[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 VIB 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 IIB metal" refers to an element that is in Group

IIB 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 IIB metal compound" refers to compounds that

include at least one element that is in Group IIB 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 VIIA 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 110° 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.

PCT/US2022/078770

[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

PCT/US2022/078770

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 1 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 (III) potassium sulfate, chromium (III) sulfate, chromium (III)

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 IIB 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 IIB metal may comprise zinc. Optionally, the conversion

composition may be substantially free, or essentially free, or completely free, of a Group IIB

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.

PCT/US2022/078770

[0080] 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

14 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.

TABLE 1

Compound Structure CAS Reg. No. Catechol Violet 115-41-3 O 0 Synonyms: OH OH I Catecholsulfonphthalein; 0=S=0 O=S=0 Pyrocatecholsulfonephthalein; HO

Pyrocatechol Violet HO Xylenol Orange 3618-43-7

Synonym: 0 OH 3,3'-Bis[N,N- 2 bis(carboxymethyl)aminomethyl]- 0 OH 0-cresolsulfonephthalein tetrasodium 0 OH HO salt N OH 0 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-

PCT/US2022/078770

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 bi- 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,

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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

5 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-

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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 pH less than 7, such as less than 6, such as less than 5.5. The pH 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 Socomore. 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,

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the phosphate may comprise phosphate (PO4), di-hydrogen phosphate (H2PO4), and/or

pyrophosphate (P2O7)4, for example, phosphate (PO4) and/or pyrophosphate (P2O7)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 organo phosphates, such as Dequest 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 IIA 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 be 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), IH-benzotriazole (CAS: 95-14-7), IH-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-thiadiazole-2-thiol, and 2-amino-1,3,4-thiadiazole (CAS: 4005-51-0). In some

embodiments, for example, the azole compound comprises 2,5-dimercapto-1,3,4-thiadiazole.

Additionally, 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 silane coupling

agent) and alcohols (collectively, "additives"). Surfactants suitable for use in the present

disclosure include Dynol 604 and Carbowet 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

10 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), OAKITE DEOXIDIZER 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

crosslinking 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, but are 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 ENVIROCRON 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 SPECTRACRON line of solvent-based coating

compositions, the AQUACRON line of water-based coating compositions, and the

RAYCRON® 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-PRF-23377

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 (Defthane 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 Defthane® ELTT/MSEPT (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

PCT/US2022/078770

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 are 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

PCT/US2022/078770

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, RO 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

31 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.

PCT/US2022/078770

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.

PCT/US2022/078770

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 Methocel A4M

as shown in Table 2. The concentrated solution of corrosion inhibitor was combined with

deionized water and dry Methoce1TM A4M powder, then stirred at high speed for six hours, to

obtain a homogenous solution.

Table 2. Corrosion inhibitor compositions

Sample Diutan Methocel TM A4M Chromium(III) Potassium gum (wt%) (wt%) chloride hexafluorozirconate hexahydrate (g/L)

(g/L)

0.20 0.0 2.2 1.5 A 0.30 0.0 2.2 1.5 B 0.40 0.0 2.2 1.5 C 0.50 0.0 2.2 1.5 D 0.10 0.0 2.2 1.5 E (comparative) 0.0 0.20 2.2 1.5 F (comparative) 0.0 2.0 2.2 1.5 G (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)

1.62 A 3.07 B 5.96 C 10.1 D E (comparative) 0.536

F (comparative) Not detected

G (comparative) Not detected

Steady shear viscosities were measured in the shear rate range of 1 to 1000 s-Superscript(1).

[0163]

Data are reported in Table 4 below.

Table 4. Viscosity Measurements

Shear Rate (s-1) Viscosity sample Viscosity sample Viscosity Sample A (mPa.s) E (mPa.s) G (mPa.s) 1 2.57x103 625 2.20x10³ 10 395 114 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.

PCT/US2022/078770

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,

10 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 ASTM D610 Area (%) Rating Area (%) Rating 1 0.139 69.116 7P 0 2 0.049 8P 75.548 0 3 0.186 7P 72.853 0 4 0.132 7P 69.128 69.128 0 5 0.123 7P 71.212 0 Average 0.126 7P 71.571 0

[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 17 Apr 2024 2022376938 17 Apr 2024

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.

[0174] In this specification where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not an admission that the document, act or item of knowledge or any combination thereof was at the priority date publicly available, known to 2022376938

the public, part of the common general knowledge or known to be relevant to an attempt to solve any problem with which this specification is concerned.

[0175] The word 'comprising' and forms of the word 'comprising' as used in this description and in the claims does not limit the invention claimed to exclude any variants or additions. additions.

39

Claims (15)

We claim: 12 Nov 2025

1. A conversion composition comprising: a yield stress component which is 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; and a corrosion inhibitor comprising trivalent chromium; wherein the conversion composition comprises a yield stress sufficient to overcome 2022376938

the effect of gravity when applied to a non-horizontal surface, and wherein the yield stress component comprises a crosslinked microgel polymer and/or a network-forming polymer comprising a biopolymer comprising at least 1 shielded charged group.

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

3. The conversion composition of either one 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 25oC when the composition is applied to a substantially vertical substrate surface, being a surface at 70° to 110° as measured from the horizontal plane, at a thickness of 12.7 to 1016 µm (0.5 mil to 40 mil; and/or

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 25oC when the composition is applied at a thickness of 12.7 to 1016 µm (0.5 mil to 40 mil) to a substantially vertical substrate surface, such as no more than 40.0 Pa; and/or

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 25oC when the composition is applied at a thickness of 12.7 to 1016 µm (0.5 mil to 40 mil) to a substantially vertical substrate surface; and/or

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 25oC; and/or

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 25oC, such as a viscosity of less than 175 mPa.s. at a shear rate of 1000 reciprocal seconds at a temperature of 25oC; and/or wherein the yield stress component comprises a pKa of 3 to 7. 12 Nov 2025

4. The conversion composition of any one of the preceding claims, wherein the crosslinked microgel polymer comprises a polyelectrolyte microgel polymer, a crosslinked nonionic microgel polymer or combinations thereof; and/or

wherein the crosslinked microgel polymer comprises a pH-activated crosslinked microgel polymer and/or an acidic moiety; and/or 2022376938

wherein the crosslinked microgel polymer comprises a carboxylic acid polymer and/or a crosslinked alkali swellable polymer; and/or

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; and/or

wherein the crosslinked microgel polymer comprises a hydrophobically modified polymer; and/or

wherein the crosslinked microgel polymer comprises an amphiphilic crosslinked nonionic polymer and/or is activatable by a surfactant; and/or

wherein the biopolymer comprises welan gum, diutan gum, or combinations thereof; and/or

wherein the biopolymer comprises no more than 4 charged groups per monosaccharide unit; and/or

wherein the charged group is shielded by a hydrophilic side group.

5. The conversion composition of any one 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; and/or

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 affecting corrosion performance and coating behaviors.

6. The conversion composition of any one of the preceding claims, wherein: 12 Nov 2025

• 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; and/or

• 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; and/or

• the conversion composition comprises the trivalent chromium in an amount of 2022376938

0.005 g/L to 2 g/L based on total weight of the conversion composition; and/or

• the trivalent chromium comprises a trivalent chrome halide, basic chrome sulfate, potassium chrome sulfate, chrome sulfate or combinations thereof.

7. The conversion composition of any one 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; and/or

wherein the conversion composition further comprises a second corrosion inhibitor and/or a conjugated compound; and/or

wherein the conversion composition further comprises a second corrosion inhibitor and the coinhibitor comprises a transition metal; and/or

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; and/or

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; and/or

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; and/or

wherein the conversion composition comprises less than 5 ppm, or less than 1 ppm, or 0 ppm, of a Group IIB metal compound and/or comprises less than 10 ppm or less than 1 ppm or less than 1 ppb of hexavalent chromium, based on the total weight of the composition; and/or wherein the conversion composition comprises a pH of less than 7. 12 Nov 2025

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

9. The system of claim 8, wherein the cleaning composition comprises a hydroxide, a phosphate, an azole or combinations thereof. 2022376938

10. 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 one of claims 1 to 7.

11. A substrate (i) comprising a film formed from the conversion composition of any one of claims 1 to 7, or

(ii) treated with the system of either one of claim 8 or claim 9, or

(iii) treated according to the method of claim 10,

wherein the substrate includes a metal substrate, metal alloy substrate or a substrate that has been metallized.

12. The substrate of claim 11, wherein the film comprises a wet film thickness of 12.7 to 1016 µm (0.5 mil to 40 mil); and/or

wherein less than 1% of an 8.88 cm2 (1.376 in2) area 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; and/or

wherein the substrate comprises a non-horizontal surface.

wherein the substrate comprises a substantially vertical surface, being a surface at 70° to 110° as measured from the horizontal plane; and/or

wherein the substrate comprises a complex substrate; and/or wherein the substrate comprises aluminum, an aluminum alloy or combinations 12 Nov 2025 thereof, and/or wherein the substrate comprises an aluminum alloy which comprises copper.

13. A use of the conversion composition of any one of claims 1 to 7 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. 2022376938

14. A use of a film formed on a surface of a substrate from the conversion composition of any one of claims 1 to 7 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 an 8.88 cm2 (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.

15. The use of claim 14, wherein the surface comprises a non-horizontal surface; and/or

wherein the surface comprises a substantially vertical surface, being a surface at 70° to 110° as measured from the horizontal plane; and/or

wherein the substrate comprises a complex substrate; and/or

wherein the use comprises a repair of the surface; and/or

wherein the substrate comprises aluminum, an aluminum alloy or combinations thereof; and/or

wherein the substrate comprises an aluminum alloy which comprises copper.