JP7191010B2 - Systems and methods for preparing processing compositions and maintaining processing baths formed therefrom - Google Patents

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is filed on June 29, 2017, and is entitled "Sealing Compositions," U.S. Provisional Application No. 62/374,188, filed on August 12, 2016. No. 62/526,382, entitled "Systems and Methods for Preparing Processing Compositions and Maintaining Processing Baths Formed Therefrom," both of which are incorporated by reference in their entireties. incorporated herein.

The present invention relates to treating compositions for treating substrates such as metal substrates, e.g., treating compositions for forming protective coatings on surfaces, and also to the preparation of such compositions and from such treating compositions. A system and method for maintaining a formed processing bath.

The use of protective coatings on metal surfaces for improved corrosion resistance and paint adhesion characteristics is well known in the metal finishing art. The prior art treats metal substrates with treatment compositions containing phosphate and chromium to promote corrosion resistance and adhesion of the coating formed by the treatment composition to the substrate surface. including. However, the use of such phosphate and/or chromate containing compositions raises environmental and health concerns. As a result, chromate-free and/or phosphate-free treatment compositions have been developed.

During a typical treatment process, when the treatment composition contacts the substrate, certain components, such as metal ions, in the treatment composition deposit or bond to the surface of the substrate to form a protective layer. As a result, the concentration of these ions in the composition can decrease during processing, which adversely affects coating characteristics and reproducibility between substrates that are successively coated in the same coating composition. may affect Thus, treating compositions that do not pose environmental and health concerns and that can be used to form protective coatings with effective anti-corrosion and adhesion characteristics on substrate surfaces, and for treating substrates It would be desirable to provide a means of avoiding or at least mitigating compositional variations and the associated adverse effects on coating characteristics and reproducibility during continued use of such compositions. Thus, the present invention is environmentally safe, health-friendly, can be manufactured from readily available resources in a cost-effective manner, and is comparable to phosphate- and/or chromate-containing compositions. It is an object of the present invention to provide a treatment composition capable of providing effective corrosion protection and forming a protective layer having adequate adhesion to the substrate surface.

Another object is a process formed from such a composition for treating a substrate that yields a coating having desired characteristics in a reproducible manner without corrosion or variations in composition affecting adhesion performance. An object of the present invention is to provide a method and system that enable continuous use of the bath.

These objects are solved by a processing composition and method for its manufacture, as well as a method and system for maintaining a processing bath, as set forth in the appended claims and described in more detail in the following description.

The treatment compositions described herein generally comprise a carbon dioxide source, lithium cations, which may be in the form of lithium salts, and an aqueous medium.

The treatment composition may comprise lithium carbonate, where the lithium carbonate may be formed by reacting carbon dioxide and lithium cations in situ in an aqueous medium.

Accordingly, the present invention combines lithium cations and carbon dioxide in an aqueous medium in an amount of 5 ppm to 5,500 ppm (calculated as lithium cations) based on the total weight of the treatment composition and the total weight of the treatment composition. of 15 ppm to 25,000 ppm (calculated as carbonate) based on the method of making a treatment composition comprising forming a treatment composition comprising carbonate in an amount (calculated as carbonate).

The present invention further relates to a system for maintaining a processing bath formed from a processing composition comprising lithium carbonate, the system comprising a lithium salt and/or carbon dioxide and optionally a hydroxide source.

Also part of the invention is a method for maintaining a treatment bath formed from a treatment composition comprising lithium carbonate, the method comprising: during and/or after treatment of a substrate with the bath; , the pH of the treatment bath to between 9.5 and 12.5, lithium in an amount of 5 ppm to 5,500 ppm (calculated as lithium cations) based on the total weight of the treatment bath, and carbonate in the total weight of the treatment bath. and supplying at least one of carbon dioxide and lithium salt to the bath in an amount sufficient to maintain an amount (calculated as carbonate) of 15 ppm to 25,000 ppm (calculated as carbonate) based on the present invention.

The invention further relates to substrates treated with such compositions and maintained treatment baths. Coating characteristics and reproducibility of coatings formed on substrates treated with such compositions and maintained treatment baths are improved over substrates treated with compositions not formed or maintained in this manner. Coating characteristics and reproducibility are more consistent on continuously processed substrates than on conventional coatings. Accordingly, protective coatings formed from compositions and treatment baths maintained in accordance with the present invention are reproducible and exhibit adequate corrosion performance and adhesion to substrate surfaces.
Although overlapping with other descriptions, the present invention is shown below.
[Invention 1]
A composition comprising lithium carbonate, wherein said lithium carbonate is formed in situ by reacting a carbon dioxide source and lithium cations in an aqueous medium.
[Invention 2]
The composition of claim 1, wherein the carbon dioxide source comprises gas, solid, or a combination thereof.
[Invention 3]
A composition according to invention 1, wherein said lithium cation is present in an amount (calculated as lithium cation) of from 5 ppm to 5500 ppm based on the total weight of the composition.
[Invention 4]
The composition according to invention 1, which has a pH of 9.5 to 12.5.
[Invention 5]
The composition according to invention 1, further comprising a hydroxide source.
[Invention 6]
The composition of claim 1, wherein said carbonate is present in an amount (calculated as carbonate) of 15 ppm to 25000 ppm based on the total weight of said treatment composition.
[Invention 7]
A substrate treated with a composition according to invention 1.
[Invention 8]
A method of making a treatment composition comprising:
combining a lithium cation and a carbon dioxide source in an aqueous medium to form the treatment composition, wherein the treatment composition contains an amount of 5 ppm to 5500 ppm (in terms of lithium cations) based on the total weight of the treatment composition; of lithium cations (calculated as carbonate) and carbonate in an amount (calculated as carbonate) of 15 ppm to 25000 ppm based on the total weight of the treatment composition;
Method.
[Invention 9]
The method of claim 8, wherein the treatment composition has a pH of 9.5-12.5.
[Invention 10]
9. The method of claim 8, further comprising adding an acid other than carbon dioxide to the treatment composition.
[Invention 11]
9. The method of claim 8, wherein the lithium cation is present as a salt comprising lithium carbonate, lithium hydroxide, or combinations thereof.
[Invention 12]
9. The method of claim 8, further comprising adding a hydroxide source to said aqueous medium.
[Invention 13]
9. The method of claim 8, wherein the hydroxide source comprises lithium hydroxide, sodium hydroxide, potassium hydroxide, or combinations thereof.
[Invention 14]
9. The method of claim 8, wherein the carbon dioxide source comprises gas, solid, or a combination thereof.
[Invention 15]
A substrate treated by the method according to Invention 8.
[Invention 16]
A system for maintaining carbonate levels in a treatment bath containing a treatment composition comprising:
lithium cations; and/or
a carbon dioxide source; and
optionally, a hydroxide source;
system including.
[Invention 17]
17. The system of claim 16, wherein said lithium cations comprise lithium carbonate, lithium hydroxide, or combinations thereof.
[Invention 18]
17. The system of claim 16, wherein the carbon dioxide source comprises gas, solid, or combinations thereof.
[Invention 19]
17. The system of claim 16, wherein said hydroxide source comprises lithium hydroxide, sodium hydroxide, potassium hydroxide, or combinations thereof.
[Invention 20]
A substrate treated with a treatment composition in a bath maintained according to the system of invention 16.
[Invention 21]
A method for maintaining carbonate levels in a treatment bath comprising a treatment composition comprising:
The pH of the treatment composition is between 9.5 and 12.5, lithium in an amount of 5 ppm to 5500 ppm (calculated as lithium cations) based on the total weight of the treatment composition, and carbonate of the treatment composition. supplying at least one of a carbon dioxide source and a lithium source to said bath in an amount sufficient to maintain an amount (calculated as carbonate) of 15 ppm to 25000 ppm based on total weight;
method including.
[Invention 22]
22. The method of claim 21, wherein the carbon dioxide source comprises gas, solid, or a combination thereof.
[Invention 23]
22. The method of claim 21, wherein the lithium source comprises lithium carbonate, lithium hydroxide, or combinations thereof.
[Invention 24]
22. The method of claim 21, further comprising supplying a hydroxide source to said bath.
[Invention 25]
22. The method of claim 21, wherein the amount of lithium carbonate in said treatment bath after said feeding is from 25 ppm to 30000 ppm (calculated as total compounds) based on the total weight of said treatment composition.
[Invention 26]
22. The method of claim 21, further comprising monitoring the pH of the treatment bath, the amount of carbonate in the treatment bath, the amount of lithium in the treatment bath, or combinations thereof.
[Invention 27]
22. The method of claim 21, further comprising adding an acid other than carbon dioxide to said treatment bath.
[Invention 28]
A substrate treated with said treatment composition in a bath maintained according to the method of invention 21.

1 shows a flow diagram detailing the sequential process used to prepare the treatment baths containing the treatment compositions used in Examples D-J.

1 shows a flow diagram detailing the sequential process used to prepare the treatment baths containing the compositions used in Examples L-O.

FIG. 2 shows a schematic showing the thickness of the layer of treatment composition on the substrate surface.

For purposes of the following detailed description, it is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary. Further, other than in any operational example or unless otherwise indicated, all numbers, such as those expressing values, amounts, percentages, ranges, subranges and fractions, are referred to as "about" even in the absence of that term. It can be read to begin with words. 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 sought to be obtained by the present invention. . At least not as an attempt to limit the application of the doctrine of equivalents to the claims, each numerical parameter is at least should be interpreted. When a closed-ended or open-ended numerical range is recited herein, all numbers, values, amounts, percentages, subranges and fractions within or within that numerical range refer to these numbers. , values, amounts, percentages, subranges and fractions are specifically included in the original disclosure of the present application as if expressly written out in their entirety and are considered to belong to the original disclosure of the present application. should.

Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention 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 deviation found in their respective testing measurements.

As used herein, unless otherwise indicated, plural terms may include their singular counterparts, and vice versa. For example, although reference is made herein to "a" lithium salt," "a" hydroxide," and "a" treatment composition, Combinations (ie, multiple) of these ingredients can be used. Additionally, in this application, the use of "or" means "and/or" unless stated otherwise, even though "and/or" may explicitly be used in certain instances.

As used herein, the terms "including," "containing," and the like are understood in the context of the present application to be synonymous with "comprising," thus open-ended and does not exclude the presence of additional undescribed and/or unquoted elements, materials, ingredients and/or method steps. As used herein, "consisting of", in the context of the present application, is understood to exclude the presence of any unspecified elements, ingredients and/or method steps. As used herein, "consisting essentially of", in the context of this application, refers to a particular element, material, ingredient and/or method step "and the basis of what is being described". "does not materially affect the original and novel features".

As used herein, "on", "onto", "applied on", "applied onto", " The terms "formed on", "deposited on", and "deposited onto" are not necessarily in contact with the surface, but It means formed on, superimposed on, deposited on, and/or provided on a surface. For example, a coating layer “formed over” a substrate excludes 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. do not exclude.

Unless otherwise disclosed herein, the term "substantially free", when used in reference to the absence of a particular material, includes the composition, the bath containing the composition, and the composition. and/or when present in a layer formed from and including the composition, present only in trace amounts of 5 ppm or less, optionally based on the total weight of the composition, bath and/or layer. means. Unless otherwise disclosed herein, the term "essentially free", when used in reference to the absence of a particular material, includes the composition, the bath containing the composition, and the composition. and/or when present in a layer formed from and including the composition, present only in trace amounts of 1 ppm or less, optionally based on the total weight of the composition, bath and/or layer. means. Unless otherwise disclosed herein, the term "completely free", when used in reference to the absence of a particular material, does not include the composition, the bath containing the composition, and/or or in a layer formed from and comprising the composition, if not present in the composition, a bath containing the composition, and/or a layer formed from and comprising the composition ( That is, it means that the composition, the bath containing the composition, and/or the layers formed from and containing the composition contain 0 ppm of such materials. If the composition, the bath containing the composition, and/or the layers formed from and containing the composition are substantially free, essentially free, or completely free of the specified material, This is because such materials may be present, for example, as a result of carryover from previous processing baths in the processing line, municipal water sources, substrates, and/or dissolution of equipment from them. means excluded.

As used herein, "salt" refers to an ionic compound composed of metal cations and non-metal anions and having an overall charge of zero. Salts may be hydrated or anhydrous.

As used herein, "aqueous composition" refers to a solution or dispersion in a medium comprising primarily water. For example, the aqueous medium is water in an amount greater than 50%, or greater than 70%, or greater than 80%, or greater than 90%, or greater than 95% by weight, based on the total weight of the medium. can include The aqueous medium may, for example, consist essentially of water.

As used herein, the term "oxidizing agent" when used in reference to a component of the sealing composition is present in the sealing composition and/or metals present in substrates that come into contact with the sealing composition. Refers to chemicals capable of oxidizing at least one of the metal-complexing agents. As used herein with respect to "oxidizing agent", the phrase "capable of oxidizing" is optionally capable of removing electrons from atoms or molecules present in the substrate or sealing composition; This means that the number of electrons can be reduced.

As used herein, the term "Group IA metal" refers to Group IA (actual ^IUPAC number (corresponding to Group 1 of the attachment).

As used herein, the term "Group IA metal compound" refers to a compound containing at least one element in Group IA of the CAS version of the Periodic Table of the Elements.

As used herein, the term "Group IIA metal" refers to Group IIA of the CAS version of the Periodic Table of the Elements (actual ^IUPAC number (corresponding to Group 2 of the attachment).

As used herein, the term "Group IIA metal compound" refers to a compound containing at least one element in Group IIA of the CAS version of the Periodic Table of the Elements.

As used herein, the term "Group IIIB metals" refers to yttrium and ^scandium in the CAS version of the Periodic Table of the Elements (the actual IUPAC (corresponding to numbering group 3). For clarity, "Group IIIB metals" specifically excludes the Lanthanide series elements.

As used herein, the term "Group IIIB metal compound" refers to a compound containing at least one element in Group IIIB of the CAS version of the Periodic Table of the Elements as defined above.

As used herein, the term "Group IVB metal" refers to Group ^IVB (actual IUPAC number (corresponding to Group 4 of the attachment).

As used herein, the term "Group IVB metal compound" refers to a compound containing at least one element in Group IVB of the CAS version of the Periodic Table of the Elements.

As used herein, the term "Group VB metal" refers to Group VB of the CAS version of the Periodic Table of the Elements (actual ^IUPAC number (corresponding to Group 5 of the attachment).

As used herein, the term "Group VB metal compound" refers to a compound containing at least one element in Group VB of the CAS version of the Periodic Table of the Elements.

As used herein, the term "Group VIB metal" refers to Group ^VIB (actual IUPAC number (corresponding to group 6 of the attachment).

As used herein, the term "Group VIB metal compound" refers to a compound containing at least one element in Group VIB of the CAS version of the Periodic Table of the Elements.

As used herein, the term "Group ^VIIB metal" refers to Group IA (actual IUPAC number (corresponding to Group 7 of the attachment).

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

As used herein, the term "Group XII metal" refers to Group IA (actual ^IUPAC number (corresponding to group 12).

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

As used herein, the term "lanthanide series elements" refers to elements 57-71 of the CAS version of the Periodic Table of the Elements, and includes the equivalents of the elements of the lanthanide series. According to the present invention, the lanthanide series elements can have both +3 and +4 common oxidation states (hereinafter referred to as +3/+4 oxidation states).

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

As used herein, a “sealing composition” affects a substrate surface or a material deposited on a substrate surface to alter the physical and/or chemical properties of the substrate surface. Refers to a composition, such as a solution or dispersion (eg, the composition provides corrosion protection).

As used herein, a "converting composition" is a composition capable of reacting with and chemically altering a substrate surface to form a film that bonds therewith to provide corrosion protection; For example, it refers to solutions or dispersions.

As used herein, "treatment bath" refers to an aqueous bath formed from the initial treatment composition. The treatment bath may contain components that are by-products of the process of contacting the substrate with the treatment composition.

As used herein, "maintaining" a processing bath formed from the processing composition means maintaining certain parameters of the processing bath, including the concentrations of certain ingredients and/or pH, within desired ranges. Point. This can be accomplished by adding one or more materials in on-shift and/or off-shift from their respective sources to the processing bath, as described in more detail below. As used herein, "on-shift" means that the article to be treated is present in the treatment bath. As used herein, "off-shift" means that no articles to be treated with the treatment composition are present in the treatment bath, but that the treatment bath is necessarily removed from the process line. not.

Pitting corrosion is the formation of localized corrosion whereby cavities or holes are created in the substrate. As used herein, the term "pit" refers to such cavities or holes resulting from pitting corrosion that are (1) rounded, elongated or irregular when viewed perpendicular to the test panel surface; regular appearance, (2) "comet-tails", lines, or "halos" (i.e., surface discoloration) arising from pitting cavities, and (3) within or immediately around pits. Characterized by the presence of corrosion by-products (eg white, gray or black granular, powdery or amorphous material). Observed surface cavities or holes must exhibit at least two of the above characteristics to be considered corrosion pits. Surface cavities or holes exhibiting only one of these characteristics may require additional analysis before being classified as corrosion pits. Visual inspection using a microscope at 10x magnification is used to determine the presence of corrosion byproducts if they are not visible to the naked eye.

As used herein, unless otherwise disclosed herein, the terms "total composition weight", "total bath weight", "total composition weight", "total treatment bath weight" or similar refers to the total weight of all ingredients present in the respective composition or bath, including any carrier and solvent.

As noted above, in accordance with the present invention, a treatment composition comprising lithium carbonate is disclosed. Lithium carbonate can be formed in situ as described above, inter alia, by reacting carbon dioxide with lithium cations, which can be in the form of lithium salts, for example, in an aqueous medium. The treatment composition can be a sealing composition, a conversion composition, and the like.

The treatment compositions of the invention are generally alkaline. According to the present invention, the pH of the treatment composition may be at least 9.5, such as at least 10, such as at least 11, and in some cases no greater than 12.5, such as no greater than 12, such as no greater than about 11.5. could be. According to the invention, the pH of the treatment composition may be from 9.5 to 12.5, such as from 10 to 12, such as from 11 to 11.5. According to the present invention, the pH of the treatment composition may be adjusted by including acidic materials including carbon dioxide, water-soluble and/or water-dispersible acids such as nitric acid, sulfuric acid, and/or phosphoric acid. According to the present invention, the pH of the treatment composition is adjusted to include carbonates such as Group I carbonates, Group II carbonates, hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, or ammonium hydroxide, ammonia. and/or the inclusion of basic materials including water-soluble and/or water-dispersible bases including amines such as triethylamine, methylethylamine, or mixtures thereof.

According to the invention, the carbon dioxide used to form the treatment composition of the invention can be gaseous, solid (ie, dry ice), or a combination thereof.

In accordance with the present invention, the lithium salts used to form the treatment compositions of the present invention can include inorganic lithium salts, organic lithium salts, or combinations thereof. According to the invention, both the anion and the cation of the lithium salt may be water soluble. According to the present invention, the lithium ^salt has a ^{solubility constant} in water (K; 25° C.). According to the invention, the lithium salt has a solubility constant in water of 1×10 ⁻¹¹ to 5×10 ⁺² , such as 1×10 ⁻⁴ to 5×10 ⁺² at a temperature of 25° C. (K; 25° C.). can. As used herein, "solubility constant" means the product of the equilibrium concentrations of ions in saturated aqueous solutions of the respective lithium salts. Each concentration is raised to the power of its respective ionic coefficient in the equilibrium equation. Solubility constants for various salts can be found in the Handbook of Chemistry and Physics. Examples of suitable lithium salts are lithium carbonate, lithium hydroxide, lithium phosphate, lithium sulfate, and lithium tetraborate.

Optionally, the treatment composition may also include hydroxides such as alkali metal hydroxides, alkaline earth metal hydroxides, or combinations thereof. According to the invention, the hydroxide can be one or more Group I hydroxides, ammonium hydroxide, or mixtures thereof. The hydroxide, if present, can be present in any amount, such as such that the pH of the treatment composition remains between 9.5 and 12.5. Non-limiting examples of Group I hydroxides include sodium hydroxide, potassium hydroxide, lithium hydroxide, or mixtures thereof. Thus, hydroxides, if used, for example lithium hydroxide, optionally in combination with other lithium salts such as lithium carbonate, are used to form the treatment composition or part thereof. It may be supplied as a lithium salt component. However, the treatment composition may also contain one or more hydroxides different from the lithium salt, such as sodium hydroxide, potassium hydroxide, or combinations thereof.

The treatment compositions of the invention generally contain an aqueous medium as a carrier. The composition may thus be in the form of a solution or dispersion of the lithium salt in the carrier.

According to the present invention, lithium carbonate is formed by combining carbon dioxide and lithium cations in an aqueous carrier medium, wherein the carbon dioxide and lithium cations are from 5 ppm to 5 ppm of lithium based on the total weight of the treatment composition. , 500 ppm (calculated as lithium cations) in the treatment composition, and the carbonate is present in the treatment composition in an amount (calculated as carbonate) of 15 ppm to 25,000 ppm based on the total weight of the treatment composition. Balance to exist in amounts that exist. Optionally, one or more pH adjusting agents, such as one or more acidic materials and/or one or more basic materials, such as one or more hydroxides, are optionally further added to the aqueous carrier medium, as described above. However, here the amounts of such optional pH modifiers, carbon dioxide and lithium salt can be balanced such that the pH of the treatment composition is between 9.5 and 12.5.

According to the present invention, the treatment composition may further comprise at least one Group IA metal cation, Group VB metal cation, and/or Group VIB metal cation other than lithium. According to the present invention, the at least one Group IA metal cation, Group VB metal cation, and/or Group VIB metal cation other than lithium may be in the form of salts and cations, each of which is equal to the total weight of the treatment composition. is present in the treatment composition in an amount (calculated as metal cation) of at least 5 ppm, such as at least 50 ppm, such as at least 150 ppm, such as at least 250 ppm, based on the total weight of the treatment composition; , 500 ppm or less, such as 1,200 ppm or less, such as 1,000 ppm or less, such as 500 ppm or less. In some cases, according to the present invention, lithium metal is present in an amount (calculated as metal cation) of 5 ppm to 5,500 ppm, such as 50 ppm to 1,000 ppm, such as 150 ppm to 500 ppm, based on the total weight of the treatment composition. It can be present in the treatment composition.

Non-limiting examples of anions suitable for forming salts with lithium cations, Group IA cations other than lithium, Group VB cations, and/or Group VIB cations include carbonates, hydroxides, nitrates, halogens, Included are sulfates, phosphates and silicates (e.g. orthosilicates and metasilicates), thus metal salts include carbonates, hydroxides, nitrates, halides, sulfates, phosphates. , silicates (eg, orthosilicates or metasilicates), permanganates, chromates, vanadates, molybdates, and/or perchlorates.

In accordance with the present invention, the metal salts of the treatment composition (i.e., lithium, Group IA metals other than lithium, Group VB, and/or Group VIB salts) are each included in the treatment composition in the total amount of the treatment composition. an amount of at least 25 ppm, such as at least 150 ppm, such as at least 500 ppm by weight (calculated as total compounds), and in some cases no more than 30,000 ppm, such as no more than 2,000 ppm, such as 1 ppm, based on the total weight of the treatment composition; , may be present in amounts up to 500 ppm (calculated as total compound). According to the present invention, the metal salts are each present in the treatment composition in an amount of 25 ppm to 30,000 ppm, such as 150 ppm to 2,000 ppm, such as 500 ppm to 1,500 ppm based on the total weight of the treatment composition (total compound calculated as ).

According to the present invention, the sealing composition of the present invention contains an oxidizing agent such as hydrogen peroxide, persulfate, perchlorate, sparged oxygen, bromate, peroxybenzoate, ozone, etc. , or combinations thereof. For example, the sealing composition may comprise 0.1% to 15%, such as 2% to 10%, such as 6% to 8%, by weight of the oxidizing agent, based on the total weight of the sealing composition. Alternatively, according to the present invention, the sealing composition may be substantially free, or in some cases essentially free, or in some cases completely free of oxidizing agents.

According to the invention, the treatment composition may exclude chromium or chromium-containing compounds. As used herein, the term "chromium-containing compound" refers to materials containing hexavalent chromium. Non-limiting examples of such materials include chromic acid, chromium trioxide, chromic anhydride, dichromates such as ammonium dichromate, sodium dichromate, potassium dichromate, and calcium dichromate. , barium, magnesium, zinc, cadmium, and strontium. If the treatment composition and/or bath, or coating or layer formed therefrom, is substantially free, essentially free, or completely free of chromium, this includes, but is not limited to, includes all forms of chromium, such as the hexavalent chromium-containing compounds listed in .

Thus, optionally according to the present invention, the treatment composition and/or treatment bath and/or coating or layer formed therefrom comprises any one or more of the elements or compounds listed in the preceding paragraphs. may be substantially free, essentially free, and/or completely free of Treatment compositions and/or baths and/or coatings or layers formed therefrom that are substantially free of chromium or chromium-containing compounds are those to which chromium or chromium-containing compounds are not intentionally added, but are free from impurities or the environment. It means that traces may be present, such as due to no contamination. In other words, the amount of material is so low that it does not affect the properties of the treatment composition and/or bath and/or coating or layer formed therefrom; It may include not being present in the treatment composition and/or bath and/or coating or layer formed therefrom at levels such that it is environmentally damaging. Thus, the term "substantially free" means, for example, that the treatment composition and/or bath and/or coating or layer formed therefrom, based on the total weight of the composition, bath, coating or layer, is can optionally mean containing less than 10 ppm of any or all of the elements or compounds listed in the preceding paragraph. The term "essentially free" means that the treatment composition and/or bath and/or coating or layer formed therefrom, based on the total weight of the composition, bath, coating or layer, if any means containing less than 1 ppm of any or all of the elements or compounds listed in the preceding paragraph. The term "completely free" means that the treatment composition and/or bath and/or coating or layer formed therefrom, based on the total weight of the composition, bath, coating or layer, if any , means containing less than 1 ppb of any or all of the elements or compounds listed in the preceding paragraph.

According to the present invention, the treatment compositions and/or treatment baths and/or coatings or layers formed therefrom in some cases contain phosphate ions or phosphate-containing compounds and/or zinc phosphate, for example. The formation of sludge, such as aluminum phosphate, iron phosphate and/or zinc phosphate, formed when using the base treatment agent can be ruled out. As used herein, "phosphate-containing compound" includes compounds containing elemental phosphorus such as orthophosphates, pyrophosphates, metaphosphates, tripolyphosphates, organophosphonates, monovalent, Divalent or trivalent cations can include, but are not limited to, sodium, potassium, calcium, zinc, nickel, manganese, aluminum and/or iron. When the treatment composition and/or bath and/or coating or layer formed therefrom is substantially free, essentially free, or completely free of phosphate, it is free of any form of phosphate ion. or containing compounds containing phosphate.

Thus, according to the present invention, the treatment compositions and/or baths and/or coatings or layers formed therefrom disclosed herein contain any one of the ions or compounds listed in the preceding paragraphs. The above may be substantially free, or in some cases essentially free, or in some cases completely free. Treatment compositions and/or baths and/or coatings or layers formed therefrom that are substantially free of phosphate contain phosphate ions or phosphate-containing compounds that are not intentionally added but are free from impurities or the environment. It means that trace amounts may be present, such as due to unavoidable contamination of In other words, the amount of material is so low that it does not affect the properties of the treatment composition and/or bath and/or coating or layer formed therefrom; any significant level in the treatment composition and/or bath and/or coating or layer formed therefrom. The term "substantially free" specifically refers to the treatment composition and/or bath and/or coating or layer, if any, based on the total weight of the composition, bath and coating or layer formed therefrom. By some it can mean containing less than 5 ppm of any or all of the phosphate anions or phosphate compounds listed in the preceding paragraph. The term "essentially free" means that the treatment composition and/or bath and/or coating or layer formed therefrom, based on the total weight of the composition, bath, coating or layer, if any means containing less than 1 ppm of any or all of the phosphate anions or phosphate compounds listed in the preceding paragraph. The term "completely free" means that the treatment composition and/or bath and/or coating or layer formed therefrom, based on the total weight of the composition, bath, coating or layer, if any , means containing less than 1 ppb of any or all of the phosphate anions or phosphate compounds listed in the preceding paragraph.
According to the present invention, the sealing composition may exclude Group IIA metal cations or Group IIA metal-containing compounds, including but not limited to calcium. Non-limiting examples of such materials include Group IIA metal hydroxides, Group IIA metal nitrates, Group IIA metal halides, Group IIA metal sulfamates, Group IIA metal sulfates, Group IIA carbonates and/or IIA group metal carboxylates. When the sealing composition and/or the coating or layer formed therefrom, respectively, is substantially free, essentially free, or completely free of Group IIA metal cations, this means any form of Group IIA Metal cations, including but not limited to the Group IIA metal-containing compounds listed above.

According to the invention, the sealing composition may in some cases exclude fluoride or a fluoride source. As used herein, "fluoride source" includes monofluorides, difluorides, fluoride complexes, and mixtures thereof known to produce fluoride ions. When the composition and/or the layer or coating comprising it is substantially free, essentially free, or completely free of fluoride, it includes any form of fluoride ion or fluoride source. but for example carryover from previous treatment baths in the treatment line, municipal water sources (e.g. fluoride added to water supply to prevent tooth decay), fluoride from pretreated substrates, etc. Contains no unintended fluorides that may be present. That is, the bath is substantially free, essentially free, or completely free of fluoride, even if the composition used to make the bath is substantially free of fluoride prior to use in the processing line. Even if they are free, essentially free, or completely free, they may have unintentional fluoride that can come from these external sources.

For example, sealing compositions include ammonium and alkali metal fluorides, acid fluorides, fluoroboric acid, fluorosilicic acid, fluorotitanic acid, and fluorozirconic acid, and their ammonium and alkali metal salts, as well as other inorganic fluorides. non-exclusive examples of which are zinc fluoride, zinc aluminum fluoride, titanium fluoride, zirconium fluoride, nickel fluoride, ammonium fluoride, fluoride Sodium, potassium fluoride, and hydrofluoric acid, as well as other similar materials known to those skilled in the art.

Fluoride present in the sealing composition that is not bound to metal ions, such as Group IVB metal ions, or to hydrogen ions, defined herein as "free fluoride," is available, for example, from Thermoscientific. Operation in a sealing composition bath using an Orion Dual Star Dual Channel Benchtop Meter equipped with a compound ion selective electrode (“ISE”), a symphony® Fluoride Ion Selective Combination Electrode supplied by VWR International or similar electrodes can be measured as a parameter. For example, Light and Cappuccino, Determination of fluoride in toothpaste using an ion-selective electron, J. Am. Chem. Educ. , 52:4, 247-250, April 1975. A fluoride ISE can be normalized by immersing the electrode in a solution of known fluoride concentration, recording the readings in millivolts, and then plotting these millivolt readings on a logarithmic graph. The millivolt reading of an unknown sample can then be compared to this calibration graph to determine fluoride concentration. Alternatively, the Fluoride ISE can be used with instruments that perform internal calibration calculations and thus can directly read the concentration of unknown samples after calibration.

Since fluoride ions are small anions with high charge densities, in aqueous solutions they are often complexed with metal ions with high positive charge densities, such as Group IVB metal ions, or hydrogen ions. A fluoride anion in solution that is ionically or covalently bound to a metal cation or hydrogen ion is defined herein as "bound fluoride." Fluoride ions complexed in this manner may be free of fluoride ions unless the solution in which they are present is mixed with an ionic strength adjusting buffer (e.g., citrate anion or EDTA), which releases fluoride ions from such complexes. Cannot measure with ISE. At that point (total) fluoride ions can be measured by a fluoride ISE and the measurement is known as "total fluoride". Alternatively, total fluoride can be calculated by comparing the weight of fluoride provided in the sealer composition to the total weight of the composition.

According to the present invention, the treatment composition is in some cases substantially free, or in some cases essentially free, or in some cases completely free of cobalt ions or cobalt-containing compounds. There is As used herein, "cobalt-containing compound" includes compounds, complexes or salts containing elemental cobalt such as, for example, cobalt sulfate, cobalt nitrate, cobalt carbonate and cobalt acetate. When the composition and/or the layer or coating comprising it is substantially free, essentially free, or completely free of cobalt, it includes any form of cobalt ion or cobalt-containing compound. .

According to the present invention, the treatment composition is in some cases substantially free, or in some cases essentially free, or in some cases completely free of vanadium ions or vanadium-containing compounds. There is As used herein, "vanadium-containing compounds" include, for example, vanadates and decavanadates containing alkali metal counterions or ammonium cations (e.g., including ammonium decavanadate sodium), Including compounds, complexes or salts containing the element vanadium. When the composition and/or the layer or coating comprising it is substantially free, essentially free, or completely free of vanadium, this includes any form of vanadium ions or compounds containing vanadium. .

In accordance with the present invention, the treatment composition may optionally further contain an indicator compound, which is so named because it indicates the presence of chemical species such as, for example, metal ions, the pH of the composition, and the like. be done. As used herein, “indicator,” “indicator compound,” and like terms refer to the presence of some external stimulus, parameter, or condition, such as the presence of metal ions, or to a particular pH or pH range. Refers to a compound that changes color in response.

Indicator compounds used in accordance with the present invention can be any indicator known in the art to indicate the presence of species, a particular pH, and the like. For example, a suitable indicator may change color after forming a metal ion complex with a particular metal ion. Metal ion indicators are generally highly conjugated organic compounds. As used herein and as understood by those of ordinary skill in the art, a "conjugated compound" refers to two double bonds separated by a single bond, such as two double bonds having a single carbon-carbon bond between them. Refers to a compound with a carbon-carbon double bond. Any conjugated compound can be used in accordance with the present invention.

Similarly, the indicator compound may change color with a change in pH; for example, the compound may be one color at acidic or neutral pH, change color at alkaline pH, Or vice versa. Such indicators are well known and widely available commercially. Thus, an indicator that "changes color when transitioning 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) indicates that the first pH having a first color (or colorless) when exposed to and transitioning to a second pH (i.e., either more acidic or alkaline than the first pH), a second Change color (or change from colorless to colored). For example, an indicator that "changes color when transitioning to a more alkaline pH (or to a less acidic pH)" would change from a first color/colorless to a second color as the pH transitions from acidic/neutral to alkaline. color/become color For example, an indicator that "changes color on transition to a more acidic pH (or to a less alkaline pH)" would change from a first color/colorless to a second color as the pH transitions from alkaline/neutral to acidic. color/become color

Non-limiting examples of such indicator compounds include methyl orange, xylenol orange, catechol violet, bromophenol blue, green and purple, erychrome black T, celestine blue, hematoxylin, carmagite, gallocyanine, and combinations thereof. included. Optionally, the indicator compound may comprise an organic indicator compound that is a metal ion indicator. Non-limiting examples of indicator compounds include those found in Table 1. Fluorescent indicators that emit light under certain conditions can also be used according to the invention, but the use of fluorescent indicators can also be specifically excluded. Thus, alternatively, conjugated compounds that exhibit fluorescence are specifically excluded. As used herein, "fluorescent indicator" and similar terms refer to compounds, molecules, pigments, and/or dyes that fluoresce or otherwise exhibit color upon exposure to ultraviolet or visible light. Point. "Fluoresce" is understood to emit light after absorption of shorter wavelength light or other electromagnetic radiation. Examples of such indicators, often referred to as "tags", include acridine, anthraquinone, coumarin, diphenylmethane, diphenylnaphthylmethane, quinoline, stilbene, triphenylmethane, anthracine and/or molecules containing any of these moieties and /or derivatives of any of these, such as rhodamine, phenanthridine, oxazine, fluorone, cyanine and/or acridine.

Conjugate compounds useful as indicators according to the present invention can include, for example, catechol violet, as shown in Table 1. Catechol Violet (CV) is a sulfonephthalein dye prepared from condensing 2 moles of pyrocatechol with 1 mole of o-sulfobenzoic anhydride. It has been found that CV has indicator properties and when incorporated into compositions with metal ions it forms a complex making it useful as a complexiometric reagent. A blue to violet color is generally observed as the CV-containing composition chelates metal ions (ie, those with a valence of two or greater) coming from the metal substrate.

As shown in Table 1, xylenol orange can also be used in compositions according to the invention. Xylenol orange has metal ion (i.e., those with a valence greater than or equal to two) indicator properties, and when incorporated into compositions with metal ions it forms a complex, making it a complexiometric It has been found to render them useful as reagents. As a composition containing xylenol orange chelates metal ions, a solution of xylenol orange turns from red to nearly blue.

According to the present invention, the indicator compound may be present in the treatment composition in an amount of at least 0.01 g/1000 g of treatment composition, such as at least 0.05 g/1000 g of treatment composition, and in some cases There may be no more than 3 g/1000 g of treatment composition, such as no more than 0.3 g/1000 g of treatment composition. According to the present invention, the indicator compound may be present in the treatment composition from 0.01 g/1000 g of treatment composition to 3 g/1000 g of treatment composition, such as from 0.05 g/1000 g of treatment composition to 0.3 g/1000 g of treatment composition. of the treatment composition.

According to the present invention, an indicator compound that changes color in response to a particular external stimulus is a treatment composition in that it can serve, for example, as a visual indication that a substrate has been treated with the composition. provide benefits when using For example, a treatment composition containing an indicator that changes color when exposed to metal ions present in a substrate will change color upon complexing with the metal ions in the substrate; contact with the composition. Similar benefits can be realized by depositing an alkaline or acidic layer on a substrate and contacting the substrate with a composition of the present invention that changes color when exposed to alkaline or acidic pH. .

Optionally, the treatment composition of the invention may further comprise a nitrogen-containing heterocyclic compound. Nitrogen-containing heterocyclic compounds include cyclic compounds having one nitrogen atom, such as pyrrole and azole compounds having two or more nitrogen atoms, such as pyrazole, imidazole, triazole, tetrazole and pentazole, one nitrogen atom and one It may contain one oxygen atom, such as oxazole and isoxazole, or one nitrogen atom and one sulfur atom, such as thiazole and isothiazole. Non-limiting examples of suitable azole compounds include 2,5-dimercapto-1,3,4-thiadiazole (CAS: 1072-71-5), 1H-benzotriazole (CAS: 95-14-7), 1H-1,2,3-triazole (CAS: 288-36-8), 2-amino-5-mercapto-1,3,4-thiadiazole (CAS: 2349-67-9) (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 includes 2,5-dimercapto-1,3,4-thiadiazole. Furthermore, according to the invention, the nitrogen-containing heterocyclic compound may be in the form of a salt such as the sodium salt.

The nitrogen-containing heterocyclic compound is present in the treatment composition at a concentration of at least 0.0005 grams per liter of composition, such as at least 0.0008 grams per liter of composition, such as at least 0.002 grams per liter of composition. may be present in the treatment composition in an amount of 3 g or less per liter of composition, such as 0.2 g or less per liter of composition, such as 0.1 g or less per liter of composition. According to the present invention, the nitrogen-containing heterocyclic compound is present (if any) in the treatment composition from 0.0005 g per liter of composition to 3 g per liter of composition, such as 0.0008 g per liter of composition. It may be present in a concentration of -0.2 g per liter of composition, such as from 0.002 g per liter of composition to 0.1 g per liter of composition.

As indicated above, the treatment compositions of the present invention contain an aqueous medium as a carrier. The aqueous carrier may optionally contain other materials such as at least one organic solvent. Non-limiting examples of suitable solvents include propylene glycol, ethylene glycol, glycerol, low molecular weight alcohols (ie C1-C12 alcohols), and the like. When present, if present, the organic solvent may be present in the treatment composition in an amount of at least 1 g of solvent per liter of treatment composition, for example at least about 2 g of solvent per liter of treatment composition; In some cases, it may be present in an amount of 40 g or less of solvent per liter of treatment composition, such as 20 g or less of solvent per liter of treatment composition. According to the present invention, the organic solvent, if present, ranges from 1 g of solvent per liter of treatment composition to 40 g of solvent per liter of treatment composition, such as from 2 g of solvent per liter of treatment composition to 1 An amount of 20 g of solvent per liter may be present in the treatment composition.

As described above, the treatment composition of the present invention described above has a lithium salt and carbon dioxide combined in an aqueous carrier medium of 5 ppm to 5,500 ppm based on the total weight of the treatment composition. amount (calculated as lithium cation) of lithium and an amount of carbonate (calculated as carbonate) of from 15 ppm to 25,000 ppm based on the total weight of the treatment composition. may Suitable lithium salts and amounts of lithium in the treatment composition are described above. For example, the lithium salt used in the method of forming the treatment composition can include lithium carbonate, lithium hydroxide, or combinations thereof. The method of making the treatment composition of the present invention includes reducing the pH of the treatment composition to a pH of at least 9.5, such as at least 10, such as at least 11, in some cases 12.5 or less, such as 12 or less, such as 11.5. It may further comprise adjusting the pH to 5 or less. Thus, according to the present invention, the treatment composition may be adjusted to have a pH of 9.5-12.5, such as 10-12, such as 11-11.5. The pH of the treatment composition can be measured according to any of the methods described below, and can be adjusted using any acid and/or base as necessary, eg, as described above.

According to the present invention, a method of making a treatment composition comprises combining carbon dioxide and a lithium salt in an aqueous medium. According to the present invention, carbon dioxide can be supplied to the aqueous carrier medium in the form of gas, solid, or a combination thereof. As used herein, "supplied" when used with respect to carbon dioxide refers to introducing carbon dioxide into the composition using a source other than the atmosphere. Carbon dioxide is at least 15 ppm, such as at least 50 ppm, such as at least 200 ppm, based on the total weight of the treatment composition, and in some cases, 25,000 ppm or less, such as 15,000 ppm or less, such as 2 , 400 ppm or less (calculated as carbonate) in an amount sufficient to form a treatment composition containing carbonate. In some cases, according to the present invention, carbon dioxide is present in an amount of 15 ppm to 25,000 ppm, such as 50 ppm to 15,000 ppm, such as 200 ppm to 2,400 ppm (calculated as carbonate) based on the total weight of the treatment composition. ) may be combined with water in an amount sufficient to form a treatment composition comprising the carbonate salt of ).

As noted above, methods of making treatment compositions according to the present invention may also include adding a hydroxide such as a Group I hydroxide, ammonium hydroxide, or mixtures thereof. The hydroxide source, if present, can be present in any amount, such as such that the pH of the treatment composition is within the range of 9.5 to 12.5. Non-limiting examples of Group I hydroxides include sodium hydroxide, potassium hydroxide, lithium hydroxide, or mixtures thereof.

As noted above, systems and methods for maintaining a processing bath formed from a processing composition comprising lithium carbonate are also disclosed in accordance with the present invention. The treatment composition can be a treatment composition described above, can be manufactured according to the methods described herein above, or can be made by any method known to those of skill in the art. In one example, according to the present invention, when "treatment bath" refers to an aqueous bath formed from an initial treatment composition comprising lithium carbonate during treatment of one or more substrates, e.g., as described above. There is When used, "maintaining" a processing bath formed from a processing composition comprising lithium carbonate (regardless of how the lithium carbonate composition was formed) includes lithium and carbonate concentrations and pH within desirable ranges, such as those indicated above for the processing compositions according to the present invention. This can be accomplished by adding one or more materials in on-shift and/or off-shift from their respective sources to the processing bath, as described in more detail below.

According to the present invention, a system or method of maintaining (i) adding a material to the treatment bath formed from the treatment composition that is different than the material used to formulate the treatment composition, and/or (ii) adding to the treatment bath formed from the treatment composition the same materials used to formulate the treatment composition; For example, a method of maintaining a processing bath containing a processing composition may include adding carbon dioxide to the processing bath, while the processing composition may be formulated using carbonates.

According to the present invention, the maintaining system or method may include adding the same materials used to formulate the treatment composition to the treatment bath containing the treatment composition. For example, the treatment composition may be formulated using carbon dioxide (as described above) and a method of maintaining a treatment bath containing the treatment composition is to add carbon dioxide to the treatment bath. can include

The systems or methods of the present invention are not directed to simply adding more processing composition to the processing bath to maintain the bath. Rather, as described above, the system and method of the present invention provide a treatment bath pH of 9.5 to 12.5 and lithium in an amount of 5 ppm to 5,500 ppm based on the total weight of the treatment bath (as lithium cations). carbon dioxide and/or lithium salt and/or hydroxide in an amount sufficient to maintain the carbonate in an amount of 15 ppm to 25,000 ppm (calculated as carbonate) based on the total weight of the treatment bath. is intended to be added to the treatment bath. The supply can be on-shift or off-shift.

As noted above, in accordance with the present invention, a system for maintaining a processing bath formed from a processing composition comprising lithium carbonate is disclosed. According to the invention, the system may contain lithium salts and/or carbon dioxide, optionally hydroxides, or any combination thereof. The lithium salt may include one or more of any of the lithium salts described above, such as lithium carbonate, lithium hydroxide, or combinations thereof. Carbon dioxide can include carbon dioxide as a gas, solid, or a combination thereof. Hydroxides can include, for example, one or more of any of the above hydroxides, such as lithium hydroxide, sodium hydroxide, potassium hydroxide, or combinations thereof. The lithium salts, carbon dioxide, and/or hydroxides described above may be included in the system individually or in any combination and are added to the treatment bath formed from the treatment composition from their respective sources in the system. can be used to achieve a treatment bath maintained to have a pH and amounts of lithium and carbonate as described above.

As noted above, a method of maintaining a processing bath formed from a processing composition comprising lithium carbonate is also disclosed in accordance with the present invention. In accordance with the present invention, the method includes, during and/or after treatment of a substrate with the bath, a pH of the treatment bath of 9.5 to 12.5 and lithium of 5 ppm based on the total weight of the treatment bath. carbon dioxide in an amount of ∼5,500 ppm (calculated as lithium cations) and in an amount sufficient to maintain carbonate in an amount of 15 ppm to 25,000 ppm (calculated as carbonate) based on the total weight of the treatment bath. and supplying at least one of a lithium salt and optionally a hydroxide to the treatment bath. The lithium salt, carbon dioxide, and hydroxide described above are added to the treatment bath formed from the treatment composition, more particularly as described above in the context of the treatment composition according to the invention. A treatment bath can be achieved that maintains a stable pH and amounts of lithium and carbonate. For example, according to the present invention, the method of maintaining includes adding carbon dioxide to the treatment bath formed from the treatment composition in an amount such that the pH of the treatment bath is maintained below 12.5, and/or It may include adding hydroxide to the treatment bath in an amount such that the pH of the treatment bath is maintained above 9.5. By way of example, in accordance with the present invention, carbon dioxide may be slowly bubbled into the treatment bath, or dry ice may be added dropwise piece by piece. According to the present invention, the pH is monitored periodically or continuously (described below) and/or hydroxide is added to the treatment bath as discussed above to bring the pH from 9.5 to 12.0. 5 may be maintained.

According to the present invention, as described above, lithium (calculated as lithium cations) is incorporated into the treatment composition after the supply of carbon dioxide and/or lithium salts and/or hydroxides in the treatment bath. may be present in an amount of at least 5 ppm, such as at least 50 ppm, such as at least 150 ppm, such as at least 250 ppm, based on the total weight of the treatment bath; It may be present in an amount of 1,000 ppm or less, such as 500 ppm or less. In some cases, according to the present invention, lithium (calculated as lithium cation), after feeding carbon dioxide and/or lithium salt, is from 5 ppm to 5,500 ppm, for example from 50 ppm to 1 ppm, based on the total weight of the treatment bath. , 200 ppm, such as from 150 ppm to 1,000 ppm, such as from 250 ppm to 500 ppm.

According to the invention, after the supply of carbon dioxide and/or lithium salt and/or hydroxide, carbonate (calculated as carbonate) is present in the treatment bath at least may be present in an amount of 15 ppm, such as at least 50 ppm, such as at least 200 ppm, and in some cases in an amount of 25,000 ppm or less, such as 15,000 ppm or less, such as 2,400 ppm or less, based on the total weight of the treatment bath; can. In some cases, according to the invention, after feeding carbon dioxide and/or lithium salt and/or hydroxide, carbonate (calculated as carbonate) is 15 ppm based on the total weight of the treatment bath. It may be present in the treatment bath in an amount of -25,000 ppm, such as 50 ppm to 15,000 ppm, such as 200 ppm to 2,400 ppm.

According to the invention, the treatment bath may have a pH of at least 9.5, such as at least 10, such as at least 11 after the supply of carbon dioxide and/or lithium salt and/or hydroxide; In some cases, it may have a pH of 12.5 or less, such as 12 or less, such as 11.5 or less. According to the invention, after the supply of carbon dioxide and/or lithium salt and/or hydroxide, the treatment bath has a pH of 9.5 to 12.5, such as 10 to 12, such as 11 to 11.5. can have

According to the present invention, the method of maintaining the treatment bath may further comprise adjusting the pH of the treatment bath, such as by adding any acid and/or base as needed. According to the present invention, the treatment bath may be maintained by including acidic materials, including water-soluble and/or water-dispersible acids, such as nitric acid, sulfuric acid, and/or phosphoric acid. According to the invention, the pH of the treatment bath is selected from Group I carbonates, Group II carbonates, hydroxides such as sodium hydroxide, potassium hydroxide, lithium hydroxide, ammonium hydroxide, ammonia, amines such as triethylamine, It can be maintained by including basic materials including water-soluble and/or water-dispersible bases such as methylethylamine, or mixtures thereof.

The method of maintaining the processing bath of the present invention may further comprise monitoring the pH of the processing bath using a pH meter and probe suitable for the size of the bath formed from the processing composition containing lithium carbonate. Examples of suitable pH meters and probes include, but are not limited to, Accumet AB15 (available from Fisher Scientific) and single junction electrodes (Ag/AgCl reference; Fisher Scientific).

The method of maintaining the processing bath of the present invention can further comprise monitoring the amount of lithium, carbonate, or lithium carbonate in the processing bath by any method known to those skilled in the art. For example, in accordance with the present invention, a method of monitoring lithium comprises, for example, an emission spectrometer or This may involve using an equivalent instrument and using a standard sample with a defined concentration of lithium (e.g., a standard of known concentration (e.g., a 500 ppm Li standard diluted to 5 ppm Li). The method of maintaining the treatment bath of the invention may further comprise monitoring the amount of carbonate in the treatment bath by any method known to those skilled in the art including, for example, using manual titration or automated titration.

Carbon dioxide and/or lithium salts, and optionally hydroxides, are added to maintain the bath (herein Dependent on bath conditions, independent It has been unexpectedly found that it may be used to maintain a processing bath formed from a lithium carbonate-containing processing composition so that it can be operated or conditioned as such. For example, using carbon dioxide and/or a lithium salt and optionally a hydroxide, the treatment bath formed from the lithium carbonate-containing treatment composition is treated at a pH of 9.5 to 12.5. To have a lithium (calculated as lithium cation) concentration of 5 ppm to 5,500 ppm based on the total weight of the bath and a carbonate (calculated as carbonate) concentration of 15 ppm to 25,000 ppm based on the total weight of the treatment bath. can be maintained.

As noted above, the treatment composition or bath formed therefrom contains an aqueous medium as a carrier. The composition or bath can thus be in the form of a solution or dispersion of the lithium salt in the carrier. According to the present invention, the solution or dispersion may be applied to the composition or bath by any of a variety of known techniques such as immersion or impregnation, spraying, intermittent spraying, immersion followed by spraying, spraying followed by immersion, brushing, or roll coating. with the substrate to be treated. According to the present invention, the solution or dispersion when applied to a substrate has a temperature of 40°F (5°C) to about 160°F (71°C), such as 60°F (16°C) to 110°F ( 43° C.). For example, the process of contacting the substrate with the treatment composition or bath may be conducted at ambient or room temperature, such as 23° C., unless otherwise indicated. Contact times are often from 1 second to 2 hours, such as from 5 minutes to 60 minutes.

According to the invention, the thickness of the layer formed by the treatment composition may be for example up to 550 nm, for example between 5 nm and 550 nm, for example between 10 nm and 400 nm, for example between 25 nm and 250 nm. The thickness of the layer formed from the treatment composition is determined using a number of analytical techniques including, but not limited to, XPS (X-ray Photoelectron Spectroscopy) depth profiling or TEM (Transmission Electron Microscopy). can be done. As used herein, "thickness", when used in reference to a layer formed by the treatment composition of the present invention, refers to (a) the thickness of the original air/substrate interface, as shown in FIG. It refers to either a layer formed above, (b) a modified layer formed below the pretreatment/substrate interface, or (c) a combination of (a) and (b). Although modified layer (b) is shown extending to the pretreatment/substrate interface in FIG. may Similarly, the combination of (a) and (b), (c), is not limited to continuous layers, but may include multiple layers with intervening layers therebetween, where the measurement of the thickness of layer (c) is may be excluded.

Suitable substrates that can be used in the present invention include metal substrates, metal alloy substrates, and/or metallized substrates such as nickel-plated plastics. According to the invention, the metal or metal alloy comprises or can be steel, aluminium, zinc, nickel and/or magnesium. For example, the steel substrate can be cold rolled steel, hot rolled steel, electrogalvanized steel, and/or hot dip galvanized steel. 1XXX, 2XXX, 3XXX, 4XXX, 5XXX, 6XXX, or 7XXX series aluminum alloys as well as clad aluminum alloys can also be used as substrates. The aluminum alloy may contain 0.01 wt% copper to 10 wt% copper. The aluminum alloy to be processed is 1XX. X, 2XX. X, 3XX. X, 4XX. X, 5XX. X, 6XX. X, 7XX. X, 8XX. X, or 9XX. Castings such as X (eg: A356.0) may also be included. AZ31B, AZ91C, AM60B, or EV31A series magnesium alloys may also be used as the substrate. Substrates used in the present invention may also comprise titanium and/or titanium alloys, zinc and/or zinc alloys, and/or nickel and/or nickel alloys. In accordance with the present invention, the substrate may be used in vehicle bodies such as, but not limited to, doors, body panels, trunk decklids, roof panels, hoods, roofs and/or stringers, rivets, landing gear components and/or aircraft. and/or a portion of the vehicle, such as the frame of the vehicle. As used herein, "vehicle" or variations thereof include, but are not limited to, civil, commercial and military aircraft, and/or land vehicles such as automobiles, motorcycles, and/or trucks.

According to the present invention, the substrate surface is treated prior to contacting at least a portion of the substrate surface with the treatment composition or bath described above to remove grease, dirt, and/or other foreign matter. may be pretreated by conventional means known in the art for cleaning and/or deoxidizing and/or otherwise cleaning or pretreating metal substrates. At least a portion of the surface of the substrate is subjected to physical and/or chemical cleaning, such as mechanically abrading the surface and/or cleaning/degreasing the surface with commercially available alkaline or acidic cleaning agents known to those skilled in the art. may be cleaned by mechanical means. Examples of alkaline cleaners suitable for use in the present invention include Chemkleen™ 166tlP, 166m/c, 177, 490MX, 2010LP, and Surface Prep 1 (SP1), Ultrax 32, Ultrax 97, Ultrax 29 and 92D. (each commercially available from PPG Industries, Inc, (Cleveland, Ohio)), and any of the DFM series, RECC 1001, and 88X1002 detergents (commercially available from PRC-DeSoto International, Sylmar, Calif.) and Turco 4215-NCLT and Ridolene (commercially available from Henkel Technologies, Madison Heights, Mich.). Such cleaning agents often precede or follow a water rinse, such as with tap water, distilled water, or combinations thereof.

As noted above, according to the present invention, at least a portion of the cleaned substrate surface may be mechanically and/or chemically deoxidized. As used herein, the term "deoxidizing" is used to promote uniform deposition of the conversion composition or pretreatment composition, as well as promote adhesion of such composition coatings to substrate surfaces. means the removal of the oxide layer found on the surface of the substrate in order to Suitable oxygen scavengers are well known to those skilled in the art. A typical mechanical oxygen scavenger can be uniform roughening of the substrate surface, such as by using a polishing pad or cleaning pad. Typical chemical oxygen scavengers include, for example, acid-based oxygen scavengers such as phosphoric acid, nitric acid, fluoroboric acid, sulfuric acid, chromic acid, hydrofluoric acid, and ammonium difluoride, or Amchem 7/17 deoxidizer. Oxygen agents (available from Henkel Technologies, Madison Heights, Mich.), OAKITE DEOXIDIZER LNC (commercially available from Chemetall), TURCO DEOXIDIZER 6 (commercially available from Henkel), or combinations thereof. Since chemical oxygen scavengers often comprise a carrier, often an aqueous medium, the oxygen scavenger may be in the form of a solution or dispersion in the carrier, where the solution or dispersion may be any The substrate may be contacted by a variety of techniques such as dipping or impregnation, spraying, intermittent spraying, dipping followed by spraying, spraying followed by dipping, brushing, or roll coating. According to the present invention, those skilled in the art will be able to Select the temperature range of the solution or dispersion when applied to the metal substrate based on the etch rate at temperatures in the range of 27° F. (27° C. to 49° C.). The contact time can be 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.

Following the cleaning and/or deoxidizing steps, the substrate may optionally be rinsed with tap water, deionized water, and/or an aqueous solution of rinse agents to remove residue. According to the present invention, the wet substrate surface may be pretreated by any method well known to those skilled in the art of substrate protection, such as treatment with an anodizing or conversion composition, and/or or the substrate is heated to an elevated temperature, such as from 15° C. to 100° C., such as from 20° C. to Water is flashed off by brief exposure of the substrate to 90° C., or in a heater assembly using, for example, infrared heat, for example at 70° C. for 10 minutes, or by passing the substrate between squeegee rolls. It may be dried, eg air dried, by drying. According to the present invention, the conversion composition may contain, for example, lanthanide series elements, Group IIIB metals, and/or Group IVB metals, and further Group IIA metals, Group VB metals, Group VIB metals, Group VIIB metals, and/or Group XII. According to the present invention, lanthanide series elements may include, for example, cerium, praseodymium, terbium, or combinations thereof; Group IIA metals may include magnesium; Group IIIB metals may include yttrium, scandium, Group IVB metals may include zirconium, titanium, hafnium, or combinations thereof; Group VB metals may include vanadium; Group VIB metals may include , trivalent or hexavalent chromium and/or molybdenum; Group VIIB metals may include manganese; Group XII metals may include zinc.

According to the present invention, after contacting the substrate with the treatment composition, a coating composition comprising a film-forming resin may be deposited onto at least a portion of the surface of the substrate contacted with the treatment composition. Any suitable technique may be used to deposit such coating compositions onto a substrate, such as brushing, dipping, flow coating, spraying, and the like. However, in some cases, as described in more detail below, the deposition of such coating compositions may include an electrodeposition step in which the electrodepositable composition is deposited onto the metal substrate by electrodeposition. . In other particular examples, deposition of such coating compositions comprises a powder coating process, as described in more detail below. In still other examples, the coating composition can be a liquid coating composition.

According to the invention, the coating composition may comprise a thermosetting film-forming resin or a thermoplastic film-forming resin. As used herein, the term "film-forming resin" means that upon removal of any diluent or carrier present in the composition, or upon curing at ambient or elevated temperatures, the Refers to a resin that can form a self-supporting continuous film. Conventional film-forming resins that may be used include, but are not limited to, automotive OEM coating compositions, automotive refinish coating compositions, industrial coating compositions, architectural coating compositions, coil coating compositions, and aerospace coatings, among others. Those commonly used in compositions can be mentioned. As used herein, the term "thermoset" refers to a resin that irreversibly "hardens" upon curing or cross-linking, wherein the polymer chains of the polymer components are bound together by covalent bonds. This property is usually associated with cross-linking reactions of the composition components, often induced by heat or radiation, for example. Curing or cross-linking reactions may also be carried out under ambient conditions. Once cured or crosslinked, thermosetting resins do not melt with the application of heat and are insoluble in solvents. As used herein, the term "thermoplastic" refers to a resin comprising polymeric components that are not covalently bonded thereby allowing liquid flow upon heating and being soluble in solvents.

As indicated above, in accordance with the present invention, an electrodepositable coating composition comprises a water-dispersible ionic salt group-containing film-forming resin that can be deposited onto a substrate by an electrodeposition coating process, wherein The depositable coating composition is deposited on the metal substrate by electrodeposition. Film-forming polymers containing ionic salt groups can include film-forming polymers containing cationic salt groups for use in cationic electrodepositable coating compositions. As used herein, the term "cationic salt group-containing film-forming polymer" refers to polymers containing at least partially neutralized cationic groups, such as sulfonium and ammonium groups, that impart a positive charge. Point. Film-forming polymers containing cationic salt groups may contain active hydrogen functional groups including, for example, hydroxyl groups, primary or secondary amine groups, and thiol groups. A cationic salt group-containing film-forming polymer containing active hydrogen functional groups may be referred to as an active hydrogen-containing cationic salt group-containing film-forming polymer. Examples of polymers suitable for use as cationic salt group-containing film-forming polymers include, but are not limited to, alkyd polymers, acrylics, polyepoxides, polyamides, polyurethanes, polyureas, polyethers, and polyesters, among others. . The cationic salt group-containing film-forming polymer is present in the cationic electrodepositable coating composition from 40% to 90% by weight, such as 50% by weight, based on the total weight of the resin solids of the electrodepositable coating composition. It may be present in an amount of up to 80% by weight, such as 60% to 75% by weight. As used herein, "resin solids" includes the ionic salt group-containing film-forming polymer, curing agent, and any additional water dispersible non-pigmenting ingredients present in the electrodepositable coating composition. .

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" means an at least partially neutralized anionic functional group, such as a negative charge. It refers to an anionic polymer containing carboxylic acid and phosphate groups to give. The anionic salt group-containing film-forming polymer may contain active hydrogen functional groups. An anionic salt group-containing film-forming polymer containing active hydrogen functional groups may be referred to as an active hydrogen-containing anionic salt group-containing film-forming polymer. Anionic salt group-containing film-forming polymers are base-solubilized carboxylic acid group-containing film-forming polymers, such as reaction products or adducts of dry oils or semi-dry fatty acid esters with dicarboxylic acids or anhydrides; It may also include the reaction product of an ester, unsaturated acid or anhydride and any additional unsaturated modifying material that is further reacted with the polyol. Also suitable are at least partially neutralized interpolymers of hydroxy-alkyl esters of unsaturated carboxylic acids, unsaturated carboxylic acids and at least one other ethylenically unsaturated monomer. Still other suitable anionic electrodepositable resins include alkyd-aminoplast vehicles, ie vehicles containing an alkyd resin and an amine-aldehyde resin. Other suitable anionic electrodepositable resin compositions include mixed esters of resinous polyols. Other acid functional polymers such as phosphorylated polyepoxides or phosphorylated acrylic polymers may also be used. Exemplary phosphorylated polyepoxides are disclosed in US Patent Application Publication No. 2009-0045071 ([0004]-[0015]) and US Patent Application No. 13/232,093 ([0014]-[0040]). and citations thereof are incorporated herein by reference. The anionic salt group-containing film-forming polymer is present in the anionic electrodepositable coating composition from 50% to 90%, such as from 55% to 80%, based on the total weight of the resin solids of the electrodepositable coating composition. may be present in an amount of, for example, 60% to 75%.

The electrodepositable coating composition may further contain a curing agent. Curing agents may react with reactive groups, such as active hydrogen groups, of the film-forming polymer containing ionic salt groups to effect curing of the coating composition to form a coating. Non-limiting examples of suitable curing agents are at least partially blocked polyisocyanates, aminoplast resins and phenoplast resins, such as phenol formaldehyde condensates, including allyl ether derivatives thereof. The curing agent is present in the cationic electrodepositable coating composition in an amount of 10 to 60 wt%, such as 20 to 50 wt%, such as 25 to 40 wt%, based on the total weight of the resin solids of the electrodepositable coating composition. can be present in an amount of Alternatively, the curing agent may be present in the anionic electrodepositable coating composition from 10 to 50% by weight, such as from 20 to 45% by weight, such as from 25% to 45% by weight, based on the total weight of the resin solids of the electrodepositable coating composition. It may be present in an amount of ˜40% by weight.

The electrodepositable coating composition may contain other optional ingredients such as pigment compositions and optionally various additives such as fillers, plasticizers, antioxidants, biocides, UV absorbers and stabilizers, hindered amines. Light stabilizers, defoamers, bactericides, dispersing aids, flow control agents, surfactants, wetting agents, or combinations thereof may also be included. The electrodepositable coating composition may contain water and/or one or more organic solvents. Water can be present, for example, in an amount of 40% to 90%, such as 50% to 75% by weight, based on the total weight of the electrodepositable coating composition. Organic solvents, if used, can typically be present in an amount of less than 10%, such as less than 5% by weight, based on the total weight of the electrodepositable coating composition. The electrodepositable coating composition can be provided in particular in the form of an aqueous dispersion. The total solids content of the electrodepositable coating composition is 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. % by weight. As used herein, "total solids" refers to the nonvolatile content of the electrodepositable coating composition, ie, materials that do not volatilize upon heating to 110°C for 15 minutes.

A cationic electrodepositable coating composition can be deposited on a conductive substrate by contacting the composition with a conductive cathode and a conductive anode, the surface to be coated being the cathode. Alternatively, an anionic electrodepositable coating composition can be deposited on a conductive substrate by contacting the composition with a conductive cathode and a conductive anode, the surface to be coated being the anode. When a sufficient voltage is applied between the electrodes, an adherent film of the electrodepositable coating composition is substantially continuously deposited on the cathode or anode, respectively. The applied voltage may vary and can range from as low as 1 volt to as high as several thousand volts, eg, 50 volts to 500 volts. Current densities are typically between 1.0 and 15 amps per square foot (10.8-161.5 amps per square meter), tend to drop off rapidly during the electrodeposition process, and are not continuous. Figure 3 shows the formation of self-insulating films.

Once the cationic or anionic electrodepositable coating composition is electrodeposited onto at least a portion of the conductive substrate, the coated substrate is exposed to a temperature sufficient to cure the electrodeposited coating on the substrate. and can be heated for a period of time. Cationic electrodeposition involves subjecting the coating substrate to 250°F to 450°F (121.1°C to 232.2°C), such as 275°F to 400°F (135°C to 204.4°C), such as 300°C. It can be heated to temperatures ranging from F to 360°F (149°C to 180°C). For anionic electrodeposition, subject the coating substrate to 200°F to 450°F (93°C to 232.2°C), such as 275°F to 400°F (135°C to 204.4°C), such as 300°F to It may be heated to a temperature in the range of 360°F (149°C to 180°C), such as 200°F to 210.2°F (93°C to 99°C). Curing time may depend on the curing temperature as well as other variables such as the thickness of the electrodeposited coating, the level and type of catalyst present in the composition, and the like. For example, curing times can range from 10 minutes to 60 minutes, such as from 20 to 40 minutes. The thickness of the resulting cured electrodeposited coating can range from 2 to 50 microns.

Alternatively, as described above, after contacting the substrate with the treatment composition according to the present invention, the powder coating composition is then applied onto at least a portion of the surface of the substrate contacted with the treatment composition. may be deposited. As used herein, "powder coating composition" refers to a coating composition that is completely free of water and/or solvent. Accordingly, the powder coating compositions disclosed herein are not synonymous with aqueous and/or solvent-based coating compositions known in the art. According to the present invention, the powder coating composition may comprise (a) a film-forming polymer having reactive functional groups; and (b) a curing agent that reacts with the functional groups. Examples of powder coating compositions that may be used in the present invention include the ENVIROCRON line of polyester-based powder coating compositions (commercially available from PPG Industries, Inc.) or epoxy-polyester hybrid powder coating compositions. Alternative powder coating compositions that may be used in the present invention include (a) at least one tertiary aminourea compound, at least one tertiary aminourethane compound, or mixtures thereof, and (b) at least one one film-forming epoxy-containing resin and/or at least one siloxane-containing resin (for example, as described in US Pat. No. 7,470,752, assigned to PPG Industries, Inc. and incorporated herein by reference); (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 (for example, described in US Pat. No. 7,432,333, assigned to PPG Industries, Inc. and incorporated herein by reference); and those comprising a solid particle mixture of a reactive group-containing polymer having a T _g of at least 30° C. (e.g., assigned to PPG Industries, Inc., by reference such as those described in US Pat. No. 6,797,387, incorporated herein).

After depositing the powder coating composition, the coating is often heated to cure the deposited composition. The heating or curing operation is often carried out at temperatures ranging from 150°C to 200°C, such as from 170°C to 190°C, for periods ranging from 10 to 20 minutes. According to the invention, the thickness of the resulting film is between 50 microns and 125 microns.

As noted above, according to the present invention, the coating composition can be a liquid coating composition. As used herein, "liquid coating composition" refers to a coating composition that contains a portion of water and/or solvent. Accordingly, the liquid coating compositions disclosed herein are synonymous with aqueous and/or solvent-based coating compositions known in the art. According to the present invention, a liquid coating composition may include, for example, (a) a film-forming polymer having reactive functional groups; and (b) a curing agent that reacts with the functional groups. In other examples, the liquid coating may contain film-forming polymers that may react with oxygen in the air or coalesce into a film upon evaporation of water and/or solvent. These film-forming mechanisms may require or be facilitated by the application of heat or some type of radiation such as ultraviolet or infrared radiation. Examples of liquid coating compositions that may be used in the present invention include the SPECTRACRON® line of solvent-based coating compositions, the AQUACRON® line of aqueous curable coating compositions, and the RAYCRON® line of solvent-based coating compositions. ) line of UV curable coatings (all commercially available from PPG Industries, Inc.). Suitable film-forming polymers that may be used in the liquid coating compositions of the present invention include (poly)esters, alkyds, (poly)urethanes, isocyanurates, (poly)ureas, (poly)epoxies, anhydrides, acrylics, (poly ) ethers, (poly)sulfides, (poly)amines, (poly)amides, (poly)vinyl chlorides, (poly)olefins, (poly)vinylidene fluorides, (poly)siloxanes or combinations thereof. .

According to the present invention, a substrate contacted with a treatment composition described herein may also be contacted with a primer composition and/or a topcoat composition. Primer coats can be, for example, chromate-based primers and high performance topcoats. In accordance with the present invention, the primer coat may be a conventional chromate-based primer coat, such as PPG Industries, Inc. (product code 44GN072), or chromium-free primers such as those available from PPG (DESOPRIME CA7502, DESOPRIME CA7521, Deft 02GN083, Deft 02GN084). Alternatively, the primer coat may be a chromate-free primer coat, such as U.S. patent application Ser. Coating compositions described in patent application Ser. and other chromium-free primers known in the art and capable of meeting the military requirements of MIL-PRF-85582 Class N or MIL-PRF-23377 Class N. can be used with the invention.

As noted above, the substrate of the present invention may also include a topcoat. As used herein, the term "topcoat" refers to a mixture of binders, which can be an organic or inorganic polymer or blend of polymers, typically at least one pigment and at least one solvent or mixture of solvents. and optionally at least one curing agent. A topcoat is usually a coating layer in a single or multilayer 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 topcoats include those complying with MIL-PRF-85285D such as those available from PPG (Deft 03W127A and Deft 03GY292). According to the present invention, the topcoat can be a high performance topcoat such as those available from PPG (Defthane® ELT™ 99GY001 and 99W009). However, other topcoats and high performance topcoats can be used with the present invention, as will be understood by those skilled in the art with reference to this disclosure.

According to the present invention, the metal substrate may also include a self-priming topcoat, or an enhanced self-priming topcoat. The term "self-priming topcoat", also called "direct to substrate" or "direct to metal" coating, refers to an organic or inorganic polymer or polymers, usually at least one pigment , optionally containing at least one solvent or solvent mixture, and optionally containing at least one curing agent. The term "reinforced self-priming topcoat", also called "direct-to-substrate reinforced coating", refers to mixtures of functionalized fluorinated binders, such as wholly or partially fluoroethylene-alkyl vinyl ethers with other binders, which can be an organic or inorganic polymer or blend of polymers, usually at least one pigment, optionally containing at least one solvent or solvent mixture, and optionally containing at least one curing agent. Examples of self-priming topcoats include those complying with TT-P-2756A. Examples of self-priming topcoats include those available from PPG (03W169 and 03GY369) and examples of enhanced self-priming topcoats available from Defthane® ELT™/ESPT and PPG. product code number 97GY121. However, other self-priming topcoats and enhanced self-priming topcoats can be used in the coating system according to the present invention, as will be understood by those skilled in the art with reference to this disclosure.

According to the present invention, self-priming topcoats and enhanced self-priming topcoats can be applied directly to the encapsulated substrate. Self-priming topcoats and enhanced self-priming topcoats can optionally be applied to organic or inorganic polymer coatings such as primers or paint films. Self-priming topcoat layers and enhanced self-priming topcoat layers are typically coating layers in single or multilayer coating systems where the outer surface of the coating is exposed to the atmosphere or environment and the inner surface of the coating is typically the substrate or optional of polymer coatings or primers.

According to the present invention, the topcoats, self-priming topcoats, and enhanced self-priming topcoats are prepared either in a wet or "uncured" state that dries or cures over time (i.e., when the solvent evaporates). and/or have a chemical reaction) can be applied to the sealing substrate. The coatings can dry or cure spontaneously or by accelerated means such as UV curing systems to form films or "cured" paints. Coatings can also be applied in a semi-cured or fully cured state, such as adhesives.

Additionally, various additives can be included in the coating composition (electrodepositable, powder or liquid) such as colorants and, optionally, surfactants, wetting agents or catalysts. As used herein, the term "colorant" means any substance that imparts color and/or other opacity and/or other visual effect to the composition. Examples of colorants include pigments, dyes and tints such as those used in the paint industry and/or those listed by the Dry Color Manufacturers Association (DCMA), as well as special effect compositions. be done. Generally, colorants can be present in the coating composition in an amount sufficient to impart the desired visual and/or color effect. Colorants may be included in weight percent based on the total weight of the composition, from 1 to 65 weight percent, such as from 3 to 40 weight percent or from 5 to 35 weight percent.

Aspects Accordingly, in view of the foregoing, the present application is directed, in particular, but not by way of limitation, to aspects 1-24 below.

1. A composition comprising carbon dioxide and lithium cations in an aqueous medium.

2. A composition according to aspect 1, wherein the carbon dioxide comprises a gas, a solid, or a combination thereof.

3. 3. The composition according to any one of aspects 1 or 2, wherein the lithium cation is present in an amount (calculated as lithium cation) of from 5 ppm to 5500 ppm based on the total weight of the treatment composition.

4. A composition according to any one of aspects 1-3, wherein the pH is between 9.5 and 12.5.

5. 5. The composition of any one of aspects 1-4, further comprising a hydroxide.

6. 6. The composition according to any one of aspects 1-5, wherein the carbonate is present in an amount (calculated as carbonate) of from 15 ppm to 25,000 ppm based on the total weight of the treatment composition.

7. A method of making a treatment composition comprising:

combining lithium cations and carbon dioxide in an aqueous medium to form a treatment composition in situ, said treatment composition containing an amount of 5 ppm to 5,500 ppm (lithium carbonate in an amount of 15 ppm to 25,000 ppm (calculated as carbonate) based on the total weight of lithium and the treatment composition (calculated as cation);
Method.

8. 8. A method of making a treatment composition according to aspect 7, wherein the lithium cation is present as lithium carbonate, lithium hydroxide, or a combination thereof.

9. 9. A method of making a treatment composition according to any one of aspects 7 or 8, wherein the carbon dioxide is supplied to the aqueous medium as a gas, solid, or a combination thereof.

10. A method of making a treatment composition according to any one of aspects 7-9 comprising adding a hydroxide to the aqueous medium.

11. 11. A method of making a treatment composition according to aspect 10, wherein the hydroxide comprises lithium hydroxide, sodium hydroxide, potassium hydroxide, or a combination thereof.

12. A method of making a treatment composition according to any one of aspects 7-11 comprising adjusting the pH of the treatment composition to 9.5-12.5.

13. A treatment composition obtainable according to the method of any one of aspects 7-12.

14. A method of maintaining a processing bath formed from a processing composition comprising lithium carbonate, comprising:

During and/or after treatment of the substrate with the bath, the pH of the bath is between 9.5 and 12.5, and lithium is added in an amount of 5 ppm to 5,500 ppm based on the total weight of the treatment bath (calculated as lithium cations). ) and at least one of carbon dioxide and a lithium salt to the bath in an amount sufficient to maintain the carbonate in an amount of 15 ppm to 25,000 ppm (calculated as carbonate) based on the total weight of the treatment bath. A method comprising providing.

15. 15. The method of maintaining a treatment bath according to aspect 14, wherein the lithium salt comprises lithium carbonate, lithium hydroxide, or a combination thereof.

16. 16. A method of maintaining a treatment bath according to any one of aspects 14 or 15, wherein carbon dioxide is supplied to the bath as a gas, solid, or a combination thereof.

17. 17. A method of maintaining a treatment bath according to any one of aspects 14-16 comprising supplying hydroxide to the bath.

18. 18. The method of maintaining a treatment bath according to aspect 17, wherein the hydroxide comprises lithium hydroxide, sodium hydroxide, potassium hydroxide, or combinations thereof.

19. Maintaining the processing bath according to any one of aspects 14-18, further comprising monitoring the pH of the processing bath, the amount of carbonate in the processing bath, the amount of lithium in the processing bath, or a combination thereof. Method.

20. A substrate treated with the treatment composition of any one of aspects 1-6 or 13 or with a treatment bath maintained according to the method of any one of aspects 14-19.

21. A system for maintaining a processing bath formed from a processing composition comprising lithium carbonate, comprising:

a lithium salt source; and/or

a carbon dioxide source; and

A system, optionally comprising a hydroxide source.

22. 22. The system for maintaining a processing bath according to aspect 21, wherein the lithium salt source comprises lithium carbonate, lithium hydroxide, or a combination thereof.

23. 23. The system for maintaining a treatment bath according to any one of aspects 21 or 22, wherein the carbon dioxide source comprises carbon dioxide as a gas, solid, or a combination thereof.

24. A system for maintaining a treatment bath according to any one of aspects 21-23, wherein the system comprises a hydroxide source comprising lithium hydroxide, sodium hydroxide, potassium hydroxide, or combinations thereof.

While specific features of the present invention have been set forth above for purposes of illustration, many of the details of the treatment composition and baths formed therefrom, and methods of preparing or maintaining the same disclosed herein, have been described. It will be apparent to those skilled in the art that modifications of can be made without departing from the scope of the appended claims.

The following examples are illustrative of the invention and should not be construed as limiting the invention to their details. All parts and percentages in the examples and herein are by weight unless otherwise indicated.
example

The ingredients and their relative amounts used to prepare the detergent/oxygen scavenger composition of Example A are provided in Table 3. Sodium hydroxide and sodium phosphate were completely dissolved in deionized water with gentle mechanical stirring using a stir plate (VWR, 7x7 CER HOT/STIR). Then when the sodium hydroxide and sodium phosphate were completely dissolved, the PVP was stirred until dissolved, then the allantoin was added and stirred until dissolved, then the DMTD was added and stirred until dissolved. After the DMTD was completely dissolved, the Carbowet GA100 was stirred under gentle mechanical agitation as above.

The ingredients and their amounts used to prepare the solution of the conversion coating treatment composition of Example B are provided in Table 4. Cerium nitrate, yttrium nitrate and cerium chloride solutions were weighed into individual cups. 500 grams of deionized water was then used to transfer the solution to a container containing 1,000 grams of deionized water with gentle agitation. The remaining 453 grams of water was added and the solution was stirred for 10 minutes to ensure homogeneity before adding the hydrogen peroxide. The final solution was stirred for a minimum of 30 minutes before use.

In preparing the sealing compositions, the pH of each Example CJ was measured using a pH meter (Accumet AB15, Fisher Scientific) and a single junction electrode (Ag/AgCl reference; Fisher Scientific), and the pH meter ( A Mettler Toledo, Seven2Go, model S2) and a double open junction electrode (Mettler Toledo, Xerolyt® polymer reference) were used to measure the pH of each example K-O.

Sealing Compositions Example C and Example K were each prepared using the ingredients shown in Table 5 by dissolving lithium carbonate in deionized water with gentle stirring using a stir plate as described above. (VWR, 7x7 CER HOT/STIR). Example C had a final pH of 11.52. Example C was used to treat the panels of Comparative Example 1 (described below). Example K had a final pH of 11.14. Example K was used to treat the panels of Comparative Example 9 (described below).

Sealing Compositions Example D and Example L were each prepared using the ingredients shown in Table 5 by dissolving lithium hydroxide in deionized water with gentle stirring using a stir plate as described above. did. Example D had a final pH value of 12.69. Example D was used to treat the panels of Comparative Example 2 (described below). Example L had a final pH value of 12.17. Example L was used to treat the panels of Comparative Example 10 (described below).

After using the bath containing the composition of Example D to treat a panel according to Comparative Example 2, carbon dioxide gas was passed into the bath containing the composition of Example D until a final pH value of 11.42 was obtained. A sealing composition example E was prepared by bubbling. See FIG. 1 and Table 5. Example E was used to treat the panels of Example 3 (described below).

After using a bath containing the composition of Example E to treat a panel according to Example 3, by bubbling additional carbon dioxide gas through the composition of Example E until a final pH value of 10.54 was obtained. Sealing Composition Example F was prepared. See FIG. 1 and Table 5. Example F was used to treat the panels of Example 4 (described below).

After using a bath containing the composition of Example F to treat a panel according to Example 4, by bubbling additional carbon dioxide gas through the composition of Example F until a final pH value of 9.47 was obtained. Sealing Composition Example G was prepared. See FIG. 1 and Table 5. Example G was used to treat the panels of Example 5 (described below).

After using the bath containing the composition of Example G to treat panels according to Example 5, 5% lithium hydroxide solution is added to the composition of Example G until a final pH value of 10.47 is obtained. Sealing Composition Example H was prepared by See FIG. 1 and Table 5. Example H was used to treat the panels of Example 6 (described below).

After using the bath containing the composition of Example H according to Example 6, the sealing composition example was prepared by adding 5% lithium hydroxide solution to the composition of Example H until a final pH value of 11.48 was obtained. I was prepared. See FIG. 1 and Table 5. Example I was used to treat the panels of Example 7 (described below).

After using the bath containing the composition of Example I according to Example 7, the sealing composition example was prepared by adding 5% lithium hydroxide solution to the composition of Example I until a final pH value of 12.47 was obtained. J was prepared. See FIG. 1 and Table 5. Example J was used to treat the panels of Example 8 (described below).

After using the bath containing the composition of Example L to treat a panel according to Comparative Example 10, carbon dioxide gas was passed into the bath containing the composition of Example L until a final pH value of 11.37 was obtained. Sealing Composition Example M was prepared by bubbling. See FIG. 2 and Table 5. Example M was used to treat the panels of Example 11 (described below).

After using a bath containing the composition of Example M to treat a panel according to Example 11, by bubbling additional carbon dioxide gas through the composition of Example M until a final pH value of 9.5 was obtained. Sealing Composition Example N was prepared. See FIG. 2 and Table 5. Example N was used to treat the panels of Example 12 (described below).

After using the bath containing the composition of Example N in accordance with Example 12, the example sealing composition was prepared by adding 5% lithium hydroxide solution to the composition of Example N until a final pH value of 11.37 was obtained. O was prepared. See FIG. 2 and Table 5. Example O was used to treat the panels of Example 13 (described below).

Panel preparation Comparative example 1
A 3 inch by 5 inch by 0.032 inch aluminum 2024T3 untreated substrate (obtained from Priority Metals, Orange County, Calif.) was manually wiped with methyl ethyl ketone and a disposable cloth and allowed to air dry prior to chemical cleaning. rice field. The panels were soaked in detergent-oxygen scavenger composition Example A for 3.5 minutes at ambient temperature with intermittent agitation. The panel was then immersed in two subsequent deionized water rinses for 2 minutes each, both with intermittent agitation, at ambient temperature. After the second rinse, the panel was rinsed with a continuous deionized water rinse for 10 seconds. The panel was then immersed in Conversion Composition Example B for 5 minutes at ambient temperature without agitation. The panel was then immersed in deionized water at ambient temperature for 2 minutes with intermittent agitation, followed by a 10 second continuous deionized water rinse. The panel was then immersed in Sealing Composition Example C for 2 minutes at ambient temperature with intermittent agitation. After the panels were air dried overnight at ambient conditions, corrosion testing was performed as described below.

Comparative example 2
A 3 inch by 5 inch by 0.032 inch aluminum 2024T3 untreated substrate (obtained from Priority Metals, Orange County, Calif.) was manually wiped with methyl ethyl ketone and a disposable cloth and allowed to air dry prior to chemical cleaning. rice field. The panels were soaked in detergent-oxygen scavenger composition Example A for 3.5 minutes at ambient temperature with intermittent agitation. The panel was then immersed in two subsequent deionized water rinses for 2 minutes each, both with intermittent agitation, at ambient temperature. After the second rinse, the panel was rinsed with a continuous deionized water rinse for 10 seconds. The panel was then immersed in Conversion Composition Example B for 5 minutes at ambient temperature without agitation. The panel was then immersed in deionized water at ambient temperature for 2 minutes with intermittent agitation, followed by a 10 second continuous deionized water rinse. The panel was then immersed in Sealing Composition Example D for 2 minutes at ambient temperature with intermittent agitation. After the panels were air dried overnight at ambient conditions, corrosion testing was performed as described below.

Example 3
After treating the panel from Comparative Example 2 through the sealing solution of Example D, the pH of the bath was adjusted by bubbling carbon dioxide gas into the bath until the pH was 11.42 (i.e. to form example E). See FIG.

An additional aluminum 2024T3 untreated substrate (Priority Metals, Orange County, Calif.) measuring 3″×5″×0.032″ was then manually wiped with methyl ethyl ketone and a disposable cloth and air dried prior to chemical cleaning. let me The panels were soaked in detergent-oxygen scavenger composition Example A for 3.5 minutes at ambient temperature with intermittent agitation. The panel was then immersed in two subsequent deionized water rinses for 2 minutes each, both with intermittent agitation, at ambient temperature. After the second rinse, the panel was rinsed with a continuous deionized water rinse for 10 seconds. The panel was then immersed in Conversion Composition Example B for 5 minutes at ambient temperature without agitation. The panel was then immersed in deionized water at ambient temperature for 2 minutes with intermittent agitation, followed by a 10 second continuous deionized water rinse. The panel was then immersed in Sealing Composition Example E for 2 minutes at ambient temperature with intermittent agitation. After the panels were air dried overnight at ambient conditions, corrosion testing was performed as described below.

Example 4
After the panels were treated through the sealing solution of Example E, the pH of the bath was adjusted by bubbling carbon dioxide gas through the bath until the pH was 10.54 (i.e., treating Example F as described above. to form). See FIG.

An additional aluminum 2024T3 untreated substrate (Priority Metals, Orange County, Calif.) measuring 3″×5″×0.032″ was then manually wiped with methyl ethyl ketone and a disposable cloth and air dried prior to chemical cleaning. let me The panels were soaked in detergent-oxygen scavenger composition Example A for 3.5 minutes at ambient temperature with intermittent agitation. The panel was then immersed in two subsequent deionized water rinses for 2 minutes each, both with intermittent agitation, at ambient temperature. After the second rinse, the panel was rinsed with a continuous deionized water rinse for 10 seconds. The panel was then immersed in Conversion Composition Example B for 5 minutes at ambient temperature without agitation. The panel was then immersed in deionized water at ambient temperature for 2 minutes with intermittent agitation, followed by a 10 second continuous deionized water rinse. The panel was then immersed in Sealing Composition Example F for 2 minutes at ambient temperature with intermittent agitation. After the panels were air dried overnight at ambient conditions, corrosion testing was performed as described below.

example 5
After the panels were treated through the sealing solution of Example F, the pH of the bath was adjusted by bubbling carbon dioxide gas through the bath until the pH was 9.47 (i.e., treating Example G as described above. to form). See FIG.

An additional aluminum 2024T3 untreated substrate (Priority Metals, Orange County, Calif.) measuring 3″×5″×0.032″ was then manually wiped with methyl ethyl ketone and a disposable cloth and air dried prior to chemical cleaning. let me The panels were soaked in detergent-oxygen scavenger composition Example A for 3.5 minutes at ambient temperature with intermittent agitation. The panel was then immersed in two subsequent deionized water rinses for 2 minutes each, both with intermittent agitation, at ambient temperature. After the second rinse, the panel was rinsed with a continuous deionized water rinse for 10 seconds. The panel was then immersed in Conversion Composition Example B for 5 minutes at ambient temperature without agitation. The panel was then immersed in deionized water at ambient temperature for 2 minutes with intermittent agitation, followed by a 10 second continuous deionized water rinse. The panel was then immersed in Sealing Composition Example G for 2 minutes at ambient temperature with intermittent agitation. After the panels were air dried overnight at ambient conditions, corrosion testing was performed as described below.

Example 6
After processing the panel through the sealing solution of Example G, the pH of the bath was adjusted with lithium hydroxide solution as described above (ie, to form Example H as described above). See FIG.

An additional aluminum 2024T3 untreated substrate (Priority Metals, Orange County, Calif.) measuring 3″×5″×0.032″ was then manually wiped with methyl ethyl ketone and a disposable cloth and air dried prior to chemical cleaning. let me The panels were soaked in detergent-oxygen scavenger composition Example A for 3.5 minutes at ambient temperature with intermittent agitation. The panel was then immersed in two subsequent deionized water rinses for 2 minutes each, both with intermittent agitation, at ambient temperature. After the second rinse, the panel was rinsed with a continuous deionized water rinse for 10 seconds. The panel was then immersed in Conversion Composition Example B for 5 minutes at ambient temperature without agitation. The panel was then rinsed with an immersion rinse in deionized water for 2 minutes at ambient temperature with intermittent agitation, followed by a continuous deionized water rinse for 10 seconds. The panel was then immersed in Sealing Composition Example H for 2 minutes at ambient temperature with intermittent agitation. After the panels were air dried overnight at ambient conditions, corrosion testing was performed as described below.

Example 7
After the panel was processed through the sealing solution of Example H, the pH of the bath was adjusted with lithium hydroxide solution as described above (ie, to form Example I as described above). See FIG.

An additional aluminum 2024T3 untreated substrate (Priority Metals, Orange County, Calif.) measuring 3″×5″×0.032″ was then manually wiped with methyl ethyl ketone and a disposable cloth and air dried prior to chemical cleaning. let me The panels were soaked in detergent-oxygen scavenger composition Example A for 3.5 minutes at ambient temperature with intermittent agitation. The panel was then immersed in two subsequent deionized water rinses for 2 minutes each, both with intermittent agitation, at ambient temperature. After the second rinse, the panel was rinsed with a continuous deionized water rinse for 10 seconds. The panel was then immersed in Conversion Composition Example B for 5 minutes at ambient temperature without agitation. The panel was then rinsed with an immersion rinse in deionized water for 2 minutes at ambient temperature with intermittent agitation, followed by a continuous deionized water rinse for 10 seconds. The panel was then immersed in Sealing Composition Example I for 2 minutes at ambient temperature with intermittent agitation. After the panels were air dried overnight at ambient conditions, corrosion testing was performed as described below.

Example 8
After the panel was processed through the sealing solution of Example I, the pH of the bath was adjusted with lithium hydroxide solution as described above (ie, to form Example I as described above). See FIG.

An additional aluminum 2024T3 untreated substrate (Priority Metals, Orange County, Calif.) measuring 3″×5″×0.032″ was then manually wiped with methyl ethyl ketone and a disposable cloth and air dried prior to chemical cleaning. let me The panels were soaked in detergent-oxygen scavenger composition Example A for 3.5 minutes at ambient temperature with intermittent agitation. The panel was then immersed in two subsequent deionized water rinses for 2 minutes each, both with intermittent agitation, at ambient temperature. After the second rinse, the panel was rinsed with a continuous deionized water rinse for 10 seconds. The panel was then immersed in Conversion Composition Example B for 5 minutes at ambient temperature without agitation. The panel was then immersed in deionized water at ambient temperature for 2 minutes with intermittent agitation, followed by a 10 second continuous deionized water rinse. The panel was then immersed in Sealing Composition Example J for 2 minutes at ambient temperature with intermittent agitation. After the panels were air dried overnight at ambient conditions, corrosion testing was performed as described below.

Comparative example 9
A 3 inch by 5 inch by 0.032 inch aluminum 2024T3 untreated substrate (obtained from Priority Metals, Orange County, Calif.) was manually wiped with methyl ethyl ketone and a disposable cloth and allowed to air dry prior to chemical cleaning. rice field. The panels were soaked in detergent-oxygen scavenger composition Example A for 3.5 minutes at ambient temperature with intermittent agitation. The panel was then immersed in two subsequent deionized water rinses for 2 minutes each, both with intermittent agitation, at ambient temperature. After the second rinse, the panel was rinsed with a continuous deionized water rinse for 10 seconds. The panel was then immersed in Conversion Composition Example B for 5 minutes at ambient temperature without agitation. The panel was then immersed in deionized water at ambient temperature for 2 minutes with intermittent agitation, followed by a 10 second continuous deionized water rinse. The panel was then immersed in Sealing Composition Example K for 2 minutes at ambient temperature with intermittent agitation. After the panels were air dried overnight at ambient conditions, corrosion testing was performed as described below.

Comparative example 10
A 3 inch by 5 inch by 0.032 inch aluminum 2024T3 untreated substrate (obtained from Priority Metals, Orange County, Calif.) was manually wiped with methyl ethyl ketone and a disposable cloth and allowed to air dry prior to chemical cleaning. rice field. The panels were soaked in detergent-oxygen scavenger composition Example A for 3.5 minutes at ambient temperature with intermittent agitation. The panel was then immersed in two subsequent deionized water rinses for 2 minutes each, both with intermittent agitation, at ambient temperature. After the second rinse, the panel was rinsed with a continuous deionized water rinse for 10 seconds. The panel was then immersed in Conversion Composition Example B for 5 minutes at ambient temperature without agitation. The panel was then immersed in deionized water at ambient temperature for 2 minutes with intermittent agitation, followed by a 10 second continuous deionized water rinse. The panel was then immersed in Sealing Composition Example L for 2 minutes at ambient temperature with intermittent agitation. After the panels were air dried overnight at ambient conditions, corrosion testing was performed as described below.

Example 11
After treating the panel from Comparative Example 10 through the sealing solution of Example L, the pH of the bath was adjusted by bubbling carbon dioxide gas into the bath until the pH was 11.37 (i.e. to form example M). See FIG.

An additional aluminum 2024T3 untreated substrate (Priority Metals, Orange County, Calif.) measuring 3″×5″×0.032″ was then manually wiped with methyl ethyl ketone and a disposable cloth and air dried prior to chemical cleaning. let me The panels were soaked in detergent-oxygen scavenger composition Example A for 3.5 minutes at ambient temperature with intermittent agitation. The panel was then immersed in two subsequent deionized water rinses for 2 minutes each, both with intermittent agitation, at ambient temperature. After the second rinse, the panel was rinsed with a continuous deionized water rinse for 10 seconds. The panel was then immersed in Conversion Composition Example B for 5 minutes at ambient temperature without agitation. The panel was then immersed in deionized water at ambient temperature for 2 minutes with intermittent agitation, followed by a 10 second continuous deionized water rinse. The panel was then immersed in Sealing Composition Example M for 2 minutes at ambient temperature with intermittent agitation. After the panels were air dried overnight at ambient conditions, corrosion testing was performed as described below.

Example 12
After the panels were treated through the sealing solution of Example M, the pH of the bath was adjusted by bubbling carbon dioxide gas through the bath until the pH was 9.50 (i.e., treating Example N as described above). to form). See FIG.

An additional aluminum 2024T3 untreated substrate (Priority Metals, Orange County, Calif.) measuring 3″×5″×0.032″ was then manually wiped with methyl ethyl ketone and a disposable cloth and air dried prior to chemical cleaning. let me The panels were soaked in detergent-oxygen scavenger composition Example A for 3.5 minutes at ambient temperature with intermittent agitation. The panel was then immersed in two subsequent deionized water rinses for 2 minutes each, both with intermittent agitation, at ambient temperature. After the second rinse, the panel was rinsed with a continuous deionized water rinse for 10 seconds. The panel was then immersed in Conversion Composition Example B for 5 minutes at ambient temperature without agitation. The panel was then immersed in deionized water at ambient temperature for 2 minutes with intermittent agitation, followed by a 10 second continuous deionized water rinse. The panel was then immersed in Sealing Composition Example N for 2 minutes at ambient temperature with intermittent agitation. After the panels were air dried overnight at ambient conditions, corrosion testing was performed as described below.

Example 13
After processing the panel through the sealing solution of Example N, the pH of the bath was adjusted with lithium hydroxide solution as described above (i.e., to form Example O as described above). See FIG.

An additional aluminum 2024T3 untreated substrate (Priority Metals, Orange County, Calif.) measuring 3″×5″×0.032″ was then manually wiped with methyl ethyl ketone and a disposable cloth and air dried prior to chemical cleaning. let me The panels were soaked in detergent-oxygen scavenger composition Example A for 3.5 minutes at ambient temperature with intermittent agitation. The panel was then immersed in two subsequent deionized water rinses for 2 minutes each, both with intermittent agitation, at ambient temperature. After the second rinse, the panel was rinsed with a continuous deionized water rinse for 10 seconds. The panel was then immersed in Conversion Composition Example B for 5 minutes at ambient temperature without agitation. The panel was then rinsed with an immersion rinse in deionized water for 2 minutes at ambient temperature with intermittent agitation, followed by a continuous deionized water rinse for 10 seconds. The panel was then immersed in sealing composition Example O for 2 minutes at ambient temperature with intermittent agitation. After the panels were air dried overnight at ambient conditions, corrosion testing was performed as described below.

Corrosion Testing Panels from Examples 1-8 were exposed for 7 days in a neutral salt spray cabinet operated according to ASTM B117. Corrosion performance was evaluated by counting the number of visible pits on the panels after 7 days of exposure. Any pits that were present prior to testing, on the edge, or resulting from scratches were excluded from the count. Corrosion performance data are reported in Table 6.

The baths from Examples 9-13 were evaluated for lithium carbonate content using an automatic titration method (Metrohm 799 GPT Titrino, Tiamo 2.3 software). % _Li2CO3 and % _{CO3 were} calculated using the following formulas:
% Li ₂ CO ₃ = [(volume at EP3−volume at EP2)×MW Li ₂ CO ₃ ×HCl concentration×100]/(SW×1000) and %CO ₃ =[(volume at EP3−volume at EP2 volume) x MW _CO3 x HCl concentration x 100]/(SW x 1000), where EP2 is the second endpoint and EP3 is the third endpoint. HCl concentration (N) was 0.1012.

These values were used to calculate the amount of carbonate in baths containing the sealing compositions of Examples 9-13, as reported in Table 6.

Comparative Examples 1 and 9 represent treatment baths containing compositions made from lithium carbonate. These examples show the pH of such treatment baths containing compositions made from lithium carbonate, and Comparative Example 9 also shows the amount of lithium carbonate and carbonate in the treatment bath. The pH of the treatment bath of Comparative Example 1 was 11.52 and there were 5 pits on the treatment panel after salt spray exposure. The treatment bath of Comparative Example 9 had a pH of 11.14 and contained 0.154% lithium carbonate and 1248 ppm carbonate.

Comparative Examples 2 and 10 showed treatment baths containing compositions made from lithium hydroxide. Specifically, the amount of lithium in Example D (used to make Comparative Example 2) was the same as the amount of lithium in Example C (used to make Comparative Example 1) (0.081 moles of lithium). . The pH of the treatment bath of Comparative Example 2 was 12.69 and there were over 100 pits on the treated panel after salt spray exposure. The treatment bath of Comparative Example 10 had a pH of 12.17 and contained 48 ppm carbonate only. While not wishing to be bound by theory, it is hypothesized that the carbonate present in the treatment bath of Comparative Example 10 is the result of conversion of _CO2 to ^CO3- . These data indicate that lithium does not provide corrosion protection to metal substrates treated in the treatment bath unless sufficient carbonate is present.

Example 3 showed that by bubbling _CO2 into the treatment bath, the pH could be lowered to a range comparable to Comparative Example 1 while reducing the number of pits on the treated panel to 6. As demonstrated by Example 11, _CO2 can also be used to form lithium carbonate in a bath with only traces of lithium carbonate prior to the addition of _CO2 .

Examples 4, 5, and 12 also showed lowering the pH by bubbling additional amounts of _CO2 into the treatment bath, but these examples are comparable to Comparative Example 1 (which has a pH of 11.52). and had 5 pits on the treated panel) and to Example 3 (had a pH of 11.42 and had 6 pits on the treated panel). As a result, as the pH of the treatment bath decreases, there is a tendency for more and more corrosion pits on the treated panels after salt spray exposure (i.e., panels treated with Examples 4 and 5 have pHs of 10.54 and 9.0, respectively). 47 had 10 and 18 pits). As shown by Example 12, 1960 ppm carbonate was present in the treatment bath. These data indicate that pH is important for corrosion performance in baths containing lithium carbonate.

Examples 6, 7, and 13 each had a pH of 10.00, since the panel treated with Example 6 had 14 pits while the panel treated with Example 7 had 3 pits. Addition of LiOH to increase to 47 and 11.48 showed improved corrosion performance.

Example 8 showed that even with sufficient carbonate levels, increasing the pH to 12.5 impairs corrosion performance, where the treated panel had 39 corrosion sites and lithium carbonate No lithium carbonate was added to the bath, an improvement compared to Comparative Example 2, which did not contain and had more than 100 pits.

Examples show the interaction of pH, lithium concentration, and carbonate concentration on corrosion resistance.

Claims (20)

A method of making a treatment composition containing lithium carbonate , comprising:
combining a lithium cation and a carbon dioxide source in an aqueous medium to form the treatment composition, wherein the treatment composition contains an amount of 5 ppm to 5500 ppm (in terms of lithium cations) based on the total weight of the treatment composition; of lithium cations (calculated) and carbonate in an amount (calculated as carbonate) of from 15 ppm to 25000 ppm based on the total weight of the treatment composition and having a pH of from 9.5 to 11.5. contains 5 ppm or less of oxidizing agent, based on the total weight of the treatment composition;
Method. 2. The method of claim 1, further comprising adding an acid other than carbon dioxide to the treatment composition. 2. The method of claim 1, wherein the lithium cation is present as a salt comprising lithium carbonate, lithium hydroxide, or combinations thereof. 2. The method of claim 1, further comprising adding a hydroxide source to said aqueous medium. 5. The method of claim 4 , wherein the hydroxide source comprises lithium hydroxide, sodium hydroxide, potassium hydroxide, or combinations thereof. 2. The method of claim 1, wherein the carbon dioxide source comprises gas, solid, or a combination thereof. A method of making a treated substrate, comprising treating the substrate with a treatment composition made by the method of claim 1 . A system for maintaining carbonate levels in a treatment bath containing a treatment composition containing lithium carbonate, comprising:
a source of a lithium source ; and/or a source of a carbon dioxide source ; and optionally a source of a hydroxide source ;
including
The pH of the treatment composition is between 9.5 and 11.5 , lithium in an amount of 5 ppm to 5500 ppm (calculated as lithium cations) based on the total weight of the treatment composition, and carbonate in the treatment composition. supplying at least one of a carbon dioxide source and a lithium source to said bath in an amount sufficient to maintain an amount (calculated as carbonate) of 15 ppm to 25000 ppm based on total weight;
system including . 9. The system of claim 8, wherein the lithium source comprises lithium carbonate, lithium hydroxide, or combinations thereof. 9. The system of Claim 8, wherein the carbon dioxide source comprises a gas, a solid, or a combination thereof. 9. The system of claim 8, wherein the hydroxide source comprises lithium hydroxide, sodium hydroxide, potassium hydroxide, or combinations thereof. 9. A method of manufacturing a treated substrate, comprising treating the substrate with a treatment composition in a bath maintained according to the system of claim 8. A method for maintaining carbonate levels in a treatment bath comprising a treatment composition containing lithium carbonate, comprising:
The pH of the treatment composition is between 9.5 and 11.5, lithium in an amount of 5 ppm to 5500 ppm (calculated as lithium cations) based on the total weight of the treatment composition, and carbonate in the treatment composition. supplying at least one of a carbon dioxide source and a lithium source to said bath in an amount sufficient to maintain an amount (calculated as carbonate) of 15 ppm to 25000 ppm based on total weight. 14. The method of claim 13, wherein the carbon dioxide source comprises gas, solid, or a combination thereof. 14. The method of claim 13, wherein the lithium source comprises lithium carbonate, lithium hydroxide, or combinations thereof. 14. The method of claim 13, further comprising supplying a hydroxide source to said bath. 14. The method of claim 13, wherein the amount of lithium carbonate in said treatment bath after said feeding is from 25 ppm to 30000 ppm (calculated as total compounds) based on the total weight of said treatment composition. 14. The method of claim 13, further comprising monitoring the pH of the processing bath, the amount of carbonate in the processing bath, the amount of lithium in the processing bath, or a combination thereof. 14. The method of claim 13, further comprising adding an acid other than carbon dioxide to the treatment bath. 14. A method of making a treated substrate, comprising treating the substrate with a treatment composition in a bath maintained according to the method of claim 13.

Images