Coating composition with catalytic system

Abstract

A coating composition is disclosed that includes a film-forming polymer that forms a reaction mixture that includes a catalytic system. The catalytic system comprises: a first catalyst comprising titanium, zirconium, or a combination thereof; and a second catalyst comprising bismuth, aluminum, zirconium, or a combination thereof wherein the metal in the first catalyst is different from the metal in the second catalyst. A method for coating at least a portion of a substrate with the coating composition is also disclosed. In addition, an article at least partially coated with the coating composition is disclosed.

Description

Technical Field

[0001] The present disclosure relates to a coating composition comprising a film-forming polymer that forms a reaction mixture, the reaction mixture comprising a catalyst system, the catalyst system comprising: a first catalyst comprising titanium or zirconium or a combination thereof; and a second catalyst comprising bismuth, aluminum, zirconium or a combination thereof; wherein the metal in the first catalyst is different from the metal in the second catalyst; relates to a method for coating a substrate, the method comprising applying the coating composition to at least a portion of the substrate; and relates to a substrate at least partially coated with the coating composition. Background Art

[0002] Coating compositions comprising film-forming polymers formed from reactions comprising catalysts have been widely used in the coating industry, such as the packaging industry, coil coating, and certain industrial and automotive coatings. Catalysts can accelerate reactions, thereby shortening manufacturing times, but typically contain potentially toxic materials, such as tin. Novel catalysts or catalyst systems for making film-forming polymers and coating compositions are desired, especially those that reduce or eliminate the use of potentially toxic materials. Summary of the Invention

[0003] The present disclosure relates to a coating composition comprising a film-forming polymer that forms a reaction mixture, the reaction mixture comprising a catalyst system, the catalyst system comprising: a first catalyst comprising titanium or zirconium or a combination thereof; and a second catalyst comprising bismuth, aluminum, zirconium or a combination thereof; wherein the metal in the first catalyst is different from the metal in the second catalyst. The present disclosure further relates to a method for coating a substrate, the method comprising applying the coating composition to at least a portion of the substrate. A substrate at least partially coated with the coating composition is also within the scope of the present invention. Brief Description of the Drawings

[0004] Figure 1 To show a graph of acid value (AV) versus reaction time, where AV is used to monitor the reaction progress. Detailed Description

[0005] For the purposes of the following detailed description, it should be understood that the present disclosure may assume various alternative variations and step sequences, unless the contrary is expressly indicated. In addition, except in any operating instances, or as otherwise indicated, all numbers expressing quantities of ingredients, for example in the specification and claims of this application, should be understood to be modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present disclosure. At the very least, and without limiting the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0006] While the numerical ranges and parameters setting forth the broad scope of the present disclosure are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0007] Also herein, a numerical range recited by endpoints includes all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.). Further, the disclosure of a range includes the disclosure of all sub-ranges subsumed within the broader range (e.g., 1 to 5 discloses 1 to 4, 1.5 to 4.5, 4 to 5, etc.). For example, a range of "1 to 10" is intended to include all sub-ranges between (and including) the recited minimum value of 1 and the recited maximum value of 10, that is, having a minimum value equal to or greater than 1 and a maximum value equal to or less than 10.

[0008] As used herein, the terms "a", "an", "the", "at least one", and "one or more" are used interchangeably. Thus, for example, a coating composition comprising "a" film-forming polymer, "a" catalyst, or "a" first and second catalyst can be interpreted to mean "one or more" of these items.

[0009] In addition, as used herein, the term "film-forming polymer" is used interchangeably with "polymer" or "resin", and refers to one or more polymers, such as homopolymers and / or copolymers, as well as prepolymers and / or oligomers, which are capable of forming a film upon reaction with a curing agent or crosslinking agent or by drying or self-crosslinking.

[0010] As used herein, the term "catalyst" refers to a substance that can cause a chemical reaction, such as the production of a polymer, to proceed at a faster rate or under different conditions (such as lower temperature). In addition, as used herein, the term "catalytic system" refers to a combination of two or more different catalysts.

[0011] As used herein, the transitional term "comprising" (and other equivalent terms such as "containing" and "including") is "open-ended" and open to include unspecified materials. Although described in terms of "including", the terms "consisting essentially of" and "consisting of" are also within the scope of this disclosure. As used herein, "consisting of" is understood in the context of this application to exclude the presence of any unspecified element, ingredient, or method step. As used herein, "consisting essentially of" is understood in the context of this application to include the specified elements, materials, ingredients, or method steps "and elements, materials, ingredients, or method steps that do not materially affect the basic and novel characteristics of the described subject matter".

[0012] Additionally, as used herein, unless specifically stated otherwise, the use of "or" means "and / or", even though "and / or" may be explicitly used in some instances.

[0013] As used herein, a "coating composition" refers to a composition that is capable of producing a film layer or the like on at least a portion of the surface of a substrate in at least a partially dried or cured state, such as a solution, mixture, powder, or dispersion.

[0014] As used herein, the term "crosslinking agent" or "curing agent" refers to a molecule that is capable of forming covalent bonds between polymers or between two different regions of the same polymer.

[0015] As used herein, a "colorant" refers to any substance that imparts color and / or other opacity and / or other visual effects to a composition.

[0016] As used herein, "ambient conditions" generally refer to temperature and humidity conditions or the temperature and humidity conditions typically found in the area where the composition is applied to a substrate, e.g., at 10°C to 40°C and 5% to 80% relative humidity, and a hot condition is a temperature above the ambient temperature. As used herein, "room temperature" generally refers to the ambient temperature, such as 10°C to 40°C. As used herein, a "substrate" can mean a bare substrate and a substrate that has been previously treated or coated with one or more layers (such as a pretreatment, primer, and / or undercoat).

[0017] As used herein, unless otherwise specified, the term "substantially free of" means that a particular material is not purposefully added to a mixture or composition separately and is present only in trace amounts of 5 ppm or less, based on the total weight of the mixture or composition. As used herein, unless otherwise specified, the term "essentially free of" means that a particular material is present only in an amount of 1 ppm or less, based on the total weight of the mixture or composition. As used herein, unless otherwise specified, the term "completely free of" means that a mixture or composition does not contain a particular material, i.e., based on the total weight of the mixture or composition, the mixture or composition contains 1 ppb or less of such material, or such material is below the detection limit of ordinary analytical techniques.

[0018] The present disclosure relates to a coating composition comprising a film-forming polymer forming a reaction mixture, the reaction mixture comprising a catalyst, wherein the catalyst comprises a catalytic system.

[0019] The film-forming polymer can comprise any polymer capable of forming a film, whether forming a film alone (such as self-crosslinking) or forming a film upon reaction with a crosslinking agent. Useful film-forming polymers include polyesters, such as polyesters having hydroxyl functional groups and / or carboxyl functional groups, and / or polyurethanes, such as polyurethanes having hydroxyl functional groups and / or isocyanate functional groups, as well as acrylic polymers and epoxy resins. The polyesters can be prepared by any suitable means known to those skilled in the art, such as by condensation.

[0020] The polyesters can be prepared from polybasic acids or their esters or acid anhydrides and polyols. Polyols are those molecules having two or more hydroxyl groups within each molecule. Non-limiting examples of polyols include propylene glycol, neopentyl glycol, butanediol, hexanediol, octanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 2-methyl-1,3-propanediol, dimethylolpropionic acid, trimethylolpropane, pentaerythritol, 4,4'-(propane-2,2-diyl)diphenol, and caprolactone diol.

[0021] Polybasic acids are those molecules containing two or more acid groups (such as carboxylic acid groups) within each molecule. Non-limiting examples of polybasic acids include terephthalic acid, isophthalic acid, adipic acid, succinic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, cyclohexanedicarboxylic acid and their acid anhydrides, such as phthalic anhydride, terephthalic anhydride and terephthalic anhydride.

[0022] The polyesters can comprise the reaction product of a polybasic acid or its ester or acid anhydride and a polyol, and / or the polyesters can comprise hydroxyl functional groups and / or carboxyl functional groups.

[0023] Polyurethanes can be prepared by any suitable means known to those skilled in the art, such as by alcoholysis.

[0024] Polyurethanes can be prepared from reaction materials such as polyisocyanates and polyols.

[0025] Polyisocyanates are those molecules having two or more isocyanate groups within each molecule. Non-limiting examples of polyisocyanates include 1,2,4-benzenetriisocyanate, polymethylene polyphenyl isocyanate, 4,4'-diphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, toluene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, m-tetramethylxylene diisocyanate, 1,4-cyclohexylene diisocyanate, isophorone diisocyanate, α,α-benzenedimethyl diisocyanate, and 4,4'-methylenebis(cyclohexyl isocyanate).

[0026] Non-limiting examples of polyols are those having two or more hydroxyl groups within each molecule, such as those described above.

[0027] The polyurethane can comprise the reaction product of a polyol and a polyisocyanate, and / or the polyurethane comprises a hydroxyl functional group.

[0028] Those skilled in the art should understand that the polymer can be processed using additional components (such as amines or epoxy resins) to impart other functional groups and / or desired properties to the cured coating composition. Examples include, but are not limited to: polyesters prepared from the adduct of ethylene oxide with N,N'-diphenylhexane-1,6-diamine or dicyclopentadiene, or polyisocyanates prepared from polyisocyanates containing substituted organic groups, where the substituents include nitro groups, chlorine groups, alkoxy groups, and other groups that do not react with hydroxyl groups or active hydrogens, provided that the position of the substituents does not render the isocyanate groups non-reactive.

[0029] Organic solvents can optionally be used in the preparation of the polymer, such as n-butanol, 2-(2-butoxyethoxy)ethanol, 2-butoxyethanol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, N-methyl-2-pyrrolidone, methyl ethyl ketone, aromatic solvents (such as light aromatic solvents, such as Aromatic 100 available from ExxonMobil), or combinations thereof.

[0030] In some cases, the polymer can be dispersed in an aqueous medium, such as by at least partially neutralizing a carboxyl-functional polymer with an amine (such as, but not limited to, ammonia, monoethanolamine, diethanolamine, or dimethylethanolamine), or by using a surfactant, or by other methods known to those skilled in the art.

[0031] As described above, the catalyst comprises a catalytic system. The catalytic system comprises: a first catalyst comprising titanium, zirconium, or a combination thereof; and a second catalyst comprising bismuth, aluminum, zirconium, or a combination thereof, wherein the metal in the first catalyst is different from the metal in the second catalyst.

[0032] The first catalyst may comprise titanium, such as Ti(OR 1 )4, wherein R 1 is an alkyl or aryl group, such as wherein R 1 is a C3-C20 alkyl group, such as wherein R 1 is n-butyl, such as tetra-n-butyl titanate (TBT), tetra-isopropyl titanate, or titanium(IV) phenoxide, or zirconium, such as Zr(OC(O)R 2 )3, wherein R 2 is an alkyl or aryl group, such as zirconium isopropoxide, zirconium butoxide, zirconium octoate, zirconium naphthenate, or a combination of any of these. Tetrabutyl titanate(IV) and similar terms may be used interchangeably with tetra-n-butyl titanate (TBT).

[0033] As described above, the second catalyst may comprise bismuth, such as Bi(OC(O)R 3 )3, wherein R 3 is an alkyl or aryl group, wherein R 3 is a C5-C20 alkyl group, such as wherein R 3 is neodecyl, such as bismuth neodecanoate, bismuth octoate, bismuth naphthenate, or a mixture of bismuth carboxylates, or the second catalyst comprises aluminum, such as Al(OC(O)R 4 )3, wherein R 4 is an alkyl or aryl group, such as aluminum oleate, aluminum octoate, or the second catalyst comprises zirconium, such as any of the foregoing zirconium compounds, such as Zr(OC(O)R 5 )3, wherein R 5 is an alkyl or aryl group or a combination of any of these.

[0034] For example, the coating composition may comprise a catalyst system, wherein the first catalyst comprises titanium, such as Ti(OR 1 )4, wherein R 1 is an alkyl or aryl group, such as wherein R 1 to C3-C20 alkyl group, such as wherein R 1 is n-butyl, such as tetrabutyl titanate, or the first catalyst comprises zirconium, such as Zr(OC(O)R 2 )3, wherein R 2 is an alkyl or aryl group, and the second catalyst comprises bismuth, such as Bi(OC(O)R 3 )3, wherein R 3 is an alkyl or aryl group, such as a C5-C20 alkyl group, such as wherein R3 is neodecyl, such as bismuth neodecanoate, or the second catalyst contains aluminum, such as Al(OC(O)R 4 )3, where R 4 is alkyl or aryl, or the second catalyst contains zirconium, such as Zr(OC(O)R 5 )3, where R 5 is alkyl or aryl.

[0035] The metal in the first catalyst of the catalyst system is different from the metal in the second catalyst. The catalyst system can include, for example, titanium and bismuth, titanium and aluminum, titanium and zirconium, zirconium and bismuth, or zirconium and aluminum. For example, the first catalyst can include titanium, such as tetrabutyl titanate, and the second catalyst can include bismuth, such as bismuth neodecanoate.

[0036] The catalyst system can include 3 to 96 parts by weight of the first catalyst and 4 to 97 parts by weight of the second catalyst, such as 7 to 43 parts by weight of the first catalyst and 9 to 42 parts by weight of the second catalyst, such as 33 parts by weight of the first catalyst and 67 parts by weight of the second catalyst, and / or based on the equivalent molar number of the first catalyst and the equivalent molar number of the second catalyst, the catalyst system can include a molar equivalent ratio of 9:1 to 1:9, such as 4:1 to 1:4, such as 1:1.

[0037] Based on the weight percentage on the resin solid, the catalyst system can be present in the film-forming polymer constituting the coating composition in an amount not exceeding 2 percent, such as 2 or less, and 1 or less, such as 0.05 or more, and 0.3 or more, such as 0.05 to 2, such as 0.42. As used herein, resin solid refers to the weight percentage of the resin remaining after incubation in an oven at, for example, 110 °C for 1 hour.

[0038] The first catalyst and the second catalyst constituting the catalyst system can be added separately to produce the film-forming polymer used in the coating composition. Optionally, the first catalyst and the second catalyst can be premixed to prepare a premixed catalyst system, sometimes also referred to herein by terms such as "premix", etc. Premixing refers to blending the components together to homogenize the first catalyst and the second catalyst or the catalyst system or to prepare a uniform blend. Premixing or blending can be carried out using any method, such as but not limited to manually stirring with a wooden or metal spatula for several minutes (such as 5 to 10 minutes), or using a motorized stirrer or homogenizer. The first catalyst and the second catalyst can be premixed before being added to the reaction to form the film-forming polymer.

[0039] During the mixing or blending process for manufacturing the premixed catalyst system, an exotherm or temperature increase of the first catalyst and the second catalyst can be observed.

[0040] The pre-mixed catalyst system can be used as soon as practically possible, or stored under ambient conditions, optionally under a nitrogen blanket, using methods known to those skilled in the art, before being used to produce the film-forming polymer in the coating composition. The premix can be stored for a period of time, such as 5 minutes to 2 months, before being used to produce the film-forming polymer in the coating system.

[0041] The catalyst system can be added at any one or more appropriate times during the production of the film-forming polymer. For example, the first catalyst and the second catalyst constituting the catalyst system can be added simultaneously, or at different times, once or multiple times to the reaction materials during the production of the film-forming polymer. In other instances, the catalyst system can be pre-mixed at any one or more stages during the production of the film-forming polymer and added as a premix. As a non-limiting example, the pre-mixed catalyst system can be added at the start of the reaction to form a film-forming polyurethane polymer.

[0042] In some cases, the catalyst systems of the present disclosure can be used to produce film-forming polymers, such as polyesters or polyurethanes, with a reduced production time compared to polymers produced using an equivalent molar amount of a single catalyst, such as tin or titanium.

[0043] As described herein, the film-forming polymer and / or coating system can be substantially free of, essentially free of, and / or completely free of catalytic tin. Examples of tin catalysts (i.e., catalysts containing "catalytic tin") include, but are not limited to, dibutyltin dilaurate, dioctyltin dilaurate; dimethyltin oxide; diethyltin oxide; dipropyltin oxide; dibutyltin oxide, dioctyltin oxide, or combinations thereof.

[0044] The coating composition can be thermoplastic. As used herein, "thermoplastic" means that the coating composition can be dried to form a film after evaporation of water and / or solvent at ambient temperature or upon exposure to heat or other sources of energy.

[0045] The coating composition can contain a crosslinking agent. The crosslinking agent can include, for example, melamine-formaldehyde, isocyanate, or blocked isocyanate that reacts with hydroxyl functional groups, or an epoxy resin that reacts with carboxyl functional groups. It should be understood that the coating compositions of the present disclosure can be cured by the reaction between the functional groups of the film-forming polymer, such as polyester or polyurethane, and the functional groups of the crosslinking agent. Curing refers to the formation of bonds between the polymer and the crosslinking agent, resulting in the formation of a crosslinked coating film. As described herein, a cured or crosslinked coating composition can be referred to as thermosetting, whether the curing is carried out under ambient conditions or upon exposure to heat or other sources of energy.

[0046] Non-limiting examples of crosslinking agents include phenolic resins, amino resins, epoxy resins, β-hydroxy(alkyl)amide resins, alkylated urethane resins, isocyanates (such as EHW8224 available from PPG), blocked isocyanates, polyacids, acid anhydrides, organometallic acid-functionalized materials, polyamines, polyamides, aminoplasts (such as CYMEL303, CYMEL 322, CYMEL 327, CYMEL 380 and CYMEL1130 (available from ALLNEX)) and mixtures thereof.

[0047] For example, the coating composition may further comprise a crosslinking agent such as an aminoplast or an isocyanate.

[0048] The crosslinking agent can be used in any weight percentage of the coating composition depending on the end use or application known to those skilled in the art.

[0049] The coating composition can include any coating composition, such as a liquid coating composition, such as a liquid coating composition at room temperature, such as a solvent-based coating composition or a water-based coating composition, and / or the coating composition can be a one-component coating composition, and / or the coating composition can be a multi-component coating composition where the resin is in one component and the crosslinking agent is thus in another component; or the coating composition can be a powder coating composition.

[0050] As used herein, a "solvent-based" coating composition refers to a coating composition dispersed or diluted in an organic medium, such as but not limited to alcohols, acetates, ketones, glycol ethers and / or hydrocarbon solvents. As used herein, a "water-based" coating composition refers to a coating composition dispersed or diluted in an aqueous medium.

[0051] As used herein, the term "organic medium" refers to a liquid medium that contains less than 50% by weight of water, based on the total weight of the organic medium. Based on the total weight of the organic medium, such an organic medium may contain less than 40% by weight of water, or less than 30% by weight of water, or less than 20% by weight of water, or less than 10% by weight of water, or less than 5% by weight of water, or less than 1% by weight of water, or less than 0.1% by weight of water, or may be water-free. Based on the total weight of the organic medium, the organic solvent accounts for more than 50% by weight of the organic medium, such as at least 70% by weight, such as at least 80% by weight, such as at least 90% by weight, such as at least 95% by weight, such as at least 99% by weight, such as at least 99.9% by weight, such as 100% by weight. Based on the total weight of the organic medium, the organic solvent may account for 50.1% to 100% by weight, such as 70% to 100% by weight, such as 80% to 100% by weight, such as 90% to 100% by weight, such as 95% to 100% by weight, such as 99% to 100% by weight, such as 99.9% to 100% by weight.

[0052] As used herein, the term "aqueous medium" refers to a liquid medium that contains at least 50% by weight of water, based on the total weight of the organic medium. Based on the total weight of the aqueous medium, such an aqueous medium may contain less than 40% by weight of organic solvent, or less than 30% by weight of organic solvent, or less than 20% by weight of organic solvent, or less than 10% by weight of organic solvent, or less than 5% by weight of organic solvent, or less than 1% by weight of organic solvent, or less than 0.1% by weight of organic solvent. Based on the total weight of the aqueous medium, water may contain more than 50% by weight, such as at least 60% by weight, such as at least 70% by weight, such as at least 80% by weight, such as at least 90% by weight, such as at least 95% by weight, such as at least 99% by weight, such as at least 99.9% by weight, such as 100% by weight of the aqueous medium. Based on the total weight of the aqueous medium, water may account for 50.1% to 100% by weight, such as 70% to 100% by weight, such as 80% to 100% by weight, such as 90% to 100% by weight, such as 70% to 100% by weight, such as 80% to 100% by weight, such as 90% to 100% by weight, such as 95% to 100% by weight, such as 99% to 100% by weight, such as 99.9% to 100% by weight.

[0053] The coating composition may comprise other polymers such as acrylates, polyesters or polyurethanes, as well as various additives. Non-limiting examples of additives that can be used with the coating compositions of the present disclosure include: colorants such as pigments or dyes that impart color to the cured film; fillers including but not limited to clays, inorganic minerals, wear-resistant particles, corrosion inhibitors, antioxidants, hindered amine light stabilizers, UV light absorbers and stabilizers, surfactants, flow and surface control agents, thixotropic agents, organic solvents, water, reactive diluents, drying agents, catalysts, reaction inhibitors, adhesion promoters and other commonly used additives.

[0054] The coating compositions of the present disclosure can be liquid coating compositions such as solvent-based coating compositions or water-based coating compositions, or the coating composition can be a powder coating composition.

[0055] The coating compositions of the present disclosure can be single-pack compositions or multi-pack compositions such as two-pack compositions. A single-pack composition is understood to mean a composition in which all coating components are stored in the same container after manufacture, during storage, etc. For certain coatings, such as thermosetting coatings that cure under ambient conditions, the various components are kept separate until application to prevent premature curing of the components. For example, the film-forming polymers (such as polyesters and / or polyurethanes or combinations thereof) can be in one pack and the crosslinking agent (such as aminoplastics or isocyanates) can be in another pack.

[0056] The coating composition can be a liquid coating composition such as a solvent-based coating composition or a water-based coating composition, or a powder coating composition, and / or the coating composition can be a single-component coating composition, and / or the coating composition can be a multi-component coating composition in which the film-forming polymer is in one component and the crosslinking agent is thus in another component.

[0057] The coating compositions prepared according to the present disclosure can be applied to a substrate by any suitable method known to those skilled in the art. Examples of such suitable application means include but are not limited to: roll coating, spraying, flow coating, spin coating, curtain coating and dip coating. Nevertheless, the coating compositions of the present disclosure are suitable for application to a substrate by roll coating techniques such as in a sheet or continuous process.

[0058] Examples of suitable substrates to which the coating compositions of the present invention can be applied include but are not limited to: metals, plastics, wood, glass, etc. For metal substrates, the coating compositions of the present invention are particularly suitable for application to electrogalvanized steel, hot-dip galvanized steel, zinc-iron alloy steel, zinc-aluminum clad steel, zinc-nickel clad steel, cold-rolled steel and aluminum.

[0059] The coating composition of the present invention can be applied to a substrate or a part thereof as a single layer or as part of a multi-layer system. The coating composition can be applied as a single layer. The coating composition can be applied to an uncoated substrate. For the avoidance of doubt, an uncoated substrate extends to a surface that is clean prior to application. The coating composition can be applied on top of another paint layer as part of a multi-layer system. For example, the coating composition can be applied on top of a primer. The coating can form a base coat or a top coat. The coating composition can form an intermediate coat or a finish coat. The coating composition can be applied as the first coat of a multi-coat system. The second coat, third coat, fourth coat, etc. can comprise any suitable paint, such as a paint containing, for example, the following: epoxy resin; polyester resin; polyurethane resin; polysiloxane resin; hydrocarbon resin or a combination thereof. The second coat, third coat, fourth coat, etc. can be a liquid coating or a powder coating. The coating composition can be applied to the substrate one or more times.

[0060] The coating composition can be applied to a package.

[0061] The package can be a metal package. Examples of metal packages include, but are not limited to, food and / or beverage packages, components for manufacturing such packages, and integral aerosol cans and / or tubes. The food and / or beverage package can be a can. Examples of suitable cans include, but are not limited to, two-piece cans, three-piece cans, etc. Suitable examples of integral aerosol cans and / or tubes include, but are not limited to, deodorant containers and hairspray containers. The single-piece aerosol can and / or tube can be an aluminum single-piece aerosol can and / or tube.

[0062] The coating composition can be applied to food and / or beverage packages and / or integral aerosol cans and / or tubes or components for manufacturing such packages.

[0063] The application of various pre-treatments and coatings for packaging is well established. For example, such treatments and / or coatings can be used in the case of metal cans, where the treatment and / or coating is used to retard or inhibit corrosion, provide a decorative coating, achieve ease of handling during the manufacturing process, etc. The coating can be applied to the interior of such cans to prevent contact of the contents with the metal of the container. For example, contact between the metal and food or beverage can cause corrosion of the metal container, which can subsequently contaminate the food or beverage. This can be true when the contents of the can are acidic in nature. The coating applied to the interior of the metal can also helps to prevent corrosion in the headspace of the can, which is the area between the product fill line and the can lid; for foods with a high salt content, corrosion in the headspace can be a problem. The coating can also be applied to the exterior of the metal can. Certain coating compositions of the present invention can be adapted for use with coiled metal blanks such as those used in manufacturing can ends (“can end blanks”) and in manufacturing end caps and closures (“lid / closure blanks”). Since the coatings designed for can end blanks and lid / seal stock can be applied before the sheet is cut and stamped from the metal coil, the coatings can be flexible and extensible. For example, such stock can be coated on both sides. Thereafter, the coated metal blank is stamped. For the can end, an “easy open” opening is then scored in the metal and an easy open ring is attached with a separately manufactured tab. The end is then attached to the can body by a seaming process. A similar procedure is carried out for an “easy open” can end. For an easy open can end, scoring substantially along the perimeter of the lid allows for easy opening or removal of the can lid, such as by means of a pull tab. For lids and closures, the lid / closure can be coated, such as by roll coating, and the lid or closure is stamped from the stock; however, it is possible to coat the lid / closure after formation. Under relatively stringent temperature and / or pressure requirements, the coatings for cans should also be able to resist cracking, corrosion, whitening, and / or blistering.

[0064] More specifically, a "package" is for containing another article, such as any substance for transporting from a manufacturing point to a consumer and subsequently stored by the consumer. Thus, a package will be understood as being sealed to keep its contents from spoiling before being opened by the consumer. Manufacturers typically identify the length of time that a food or beverage will not spoil, which can range from several months to several years. Thus, this "package" is different from a storage container or baking pan used by a consumer to make and / or store food; such containers can only keep food fresh or intact for a relatively short time. The package according to the present invention can be made of metal or non-metal, such as plastic or laminate, and can be in any form. Examples of suitable packages are laminated tubes. Another example of a suitable package is a metal can. The term "metal can" includes any type of metal can, container, or any type of reservoir or part thereof that is sealed by a food and / or beverage manufacturer to minimize or eliminate spoilage of the contents before the consumer opens such a package. An example of a metal can is a food can; the term "food can" is used herein to refer to a can, container, or any type of reservoir or part thereof for containing any type of food and / or beverage. The term "metal can" specifically includes food cans and also specifically includes "can ends", which include "E-Z openings", which can be stamped from endstock and used in conjunction with the packaging of food and beverages. The term "metal can" also specifically includes metal lids and / or closures, such as bottle caps, screw-top lids, and lids, snap-on lids, etc. of any size. Metal cans can also be used to contain other articles, including but not limited to personal care products, insect sprays, paint sprays, and any other compounds suitable for packaging in aerosol cans. Cans can include "two-piece cans" and "three-piece cans" as well as thin-wall drawn integral cans; such integral cans are typically used for aerosol products. The coated package according to the present invention can also include plastic bottles, plastic tubes, laminates, and flexible packages, such as those made of PE, PP, PET, etc. Such packages can contain, for example, food, toothpaste, personal care products, etc.

[0065] The coating composition can be applied to the interior and / or exterior of the package.

[0066] The coating composition can be applied to the "side seam" of a metal can, which will be understood as the seam formed during the manufacture of a three-piece can. The coating composition can also be applied as an edge coating to the bottom of the can. The role of the edge coating is to reduce friction to improve the operation during continuous manufacture and / or handling of the can. The coating composition can also be applied to the lid and / or closure; such application can include, for example, a protective varnish applied before and / or after the formation of the lid / closure and / or a colored enamel post applied to the lid, such as those having a scored seam at the bottom of the lid. Decorative can blanks can also be coated on the outer portion with the coating described herein, and the decorated coated can blanks are used to form various metal cans.

[0067] The coating composition can be a post - repair coating composition, such as a post - repair spray coating composition. Such coating compositions are specifically designed to be applied to and thereby coat the scored lines of the packaging. During the scoring operation (which is typically achieved by stamping with a stamping machine), the outer varnish layer is cut, and thus the corrosion resistance of the metal substrate is impaired. This can be particularly problematic in the following cases:

[0068] i) The metal is stressed and thus its corrosion resistance is weakened; and / or

[0069] ii) The tin layer of the tinplate (where this is the substrate) is also cut; and / or

[0070] iii) The next processing step of the packaging is sterilization, where the presence of heat and high humidity will create high - corrosion conditions; and / or

[0071] iv) The container is at the beginning stage of its life cycle, which is at least two years.

[0072] The corrosion resistance of the metal substrate is restored by applying a post - repair coating (produced from the post - repair coating composition) to the scored line. This coating is typically applied by spraying, such as by the airless spraying method.

[0073] The coating composition can be a one - component coating composition (commonly referred to as a 1K coating composition) or a multi - component coating composition, such as a two - component coating composition (commonly referred to as a 2K coating composition). This terminology is well - known in the art. In a multi - component coating composition, the components are provided separately but are introduced into each other (e.g., by mixing) before application. This can be several hours before application, such as up to 24 hours before application, or up to 12 hours before application, or up to 8 hours before application, or up to 4 hours before application. In some cases, for example, the multi - components can be introduced into each other (such as by mixing) during the application process, such as in - line mixing. If the coating composition is a multi - component coating composition, such as a 2 - component coating composition, the thermoplastic particles can be provided in the first component, while other materials can be provided in another component (such as the second component). For example, the cross - linker material can be provided in another component (such as the second component).

[0074] The coating composition can be a one - component coating composition.

[0075] The coating composition can be a 1K coating composition.

[0076] Metal coils, which have a wide range of applications in many industries, are also substrates that can be coated according to the present invention. The coil coating can contain colorants.

[0077] The coating composition is applied to at least a portion of the package. For example, when applying the coating composition to a food and / or beverage can and / or an integral aerosol can and / or a tube, the coating composition can be applied to at least a portion of the inner surface and / or the outer surface of the food and / or beverage can and / or the integral aerosol can and / or the tube. For example, when applying the coating composition to a food and / or beverage can, the coating composition can be applied to at least a portion of the inner surface of the food and / or beverage can.

[0078] The package can be formed from any suitable material. Suitable materials are known to those skilled in the art. Examples of suitable materials include, but are not limited to: steel; tinplate; tinplate pretreated with a protective material such as chromium, titanium, titanate, or aluminum; tin-free steel (TFS); galvanized steel, such as, for example, electro-galvanized steel; aluminum; aluminum alloys; and combinations thereof. The package can be formed from: steel; tinplate; tinplate pretreated with a protective material such as chromium, titanium, titanate, or aluminum; tin-free steel (TFS); galvanized steel, such as, for example, electro-galvanized steel; or combinations thereof.

[0079] The package can be formed from chromium-free materials. As used herein, "chromium-free" means a material that may or may not undergo a pretreatment process. When the material undergoes a pretreatment process involving passivation, the passivation solution is substantially free of, may be essentially free of, or may be completely free of chromium compounds, such as, for example, sodium dichromate. "Substantially free of" means that the passivation solution contains less than 1000 parts per million (ppm) of chromium compounds, such as, for example, sodium dichromate. "Essentially free of" means that the passivation solution contains less than 100 ppm of chromium compounds, such as, for example, sodium dichromate. "Completely free of" means that the passivation solution contains less than 20 parts per billion (ppb) of chromium compounds, such as, for example, sodium dichromate. The passivation process may not include chromium compounds, such as hexavalent chromium compounds. For example, the passivation process may not include contacting the material with a solution comprising a chromium compound (such as a hexavalent chromium compound) and / or immersing the material in the solution.

[0080] The passivation process can include the 505 or 555 method of passivation, such as the 505 or 555 passivation method from Arcelor, TATA, or US Steel, and / or a passivation method based on Henkel Granodine 1456. Chromium-free materials can be obtained from commercial sources.

[0081] The coating composition can be applied to a substrate (package) by any suitable method. Methods of applying the coating composition are known to those skilled in the art. Suitable application methods include, but are not limited to: electrophoretic coating (such as electrodeposition); spraying; electrostatic spraying; dip coating; roll coating; brush coating; and the like. The coating composition can be applied to the substrate by spraying and / or roll coating. For example, the coating composition can be applied to a flat sheet by roll coating before forming a can (such as a three-piece can) from the flat sheet. The coating composition can be applied to a metal substrate by lamination. For example, a film can be formed from the coating composition, and the film can then be applied to a metal substrate (package, such as a food or beverage can) by lamination.

[0082] The package can be at least partially coated with the coating composition of the present disclosure. The package can include, for example, a metal can and / or an integral aerosol can and / or a tube. The package can be used for and / or include, for example, food and / or beverage packaging.

[0083] Once the coating is applied to the desired substrate, it can be dried or cured by any suitable means known to those skilled in the art that is appropriate for the film-forming agent chemistry. Examples of such suitable curing techniques include, but are not limited to: baking in a hot oven, induction heating, infrared heating, exposure to actinic radiation, and / or combinations thereof.

[0084] The coating composition of the present disclosure can include any coating, such as a primer, a colored base coat, and / or a top coat. The coating deposited from the composition of the present invention can have one or more additional coatings deposited below and / or above the layer. For example, the coating of the present disclosure can include a first coating, and one or more additional coatings, the same or different from the coating composition of the present disclosure, can be applied over at least a portion of the first coating. One of the multiple additional coatings can be applied to the at least partially cured first coating, such as a silicone-modified polyester coating composition, a polyvinylidene fluoride coating composition, or a combination thereof. One or more additional coatings can also be applied below the coating formed from the composition of the present invention.

[0085] The coating composition of the present disclosure can be applied to a substrate by any method, and the substrate can be coated by any method, such as applying a first coating comprising the coating composition of the present disclosure to at least a portion of the substrate, and optionally, applying one or more additional coatings to at least a portion of the first coating, such as where one or more of the additional coatings comprise the coating composition of the present disclosure, a silicone-modified polyester coating composition, a polyvinylidene fluoride coating composition, or a combination thereof.

[0086] A substrate at least partially coated with the coating composition of the present disclosure can include any substrate. For example, a substrate at least partially coated with the coating composition of the present disclosure can include plastics (such as polycarbonate), glass, wood, or metals or metal alloys (such as aluminum or steel), in the form of, for example, metal sheets or metal coils. A substrate at least partially coated with the coating composition of the present disclosure can include at least one additional coating, such as where the one or more additional coatings include a coating composition according to the present disclosure, a silicone-modified polyester coating, a polyvinylidene fluoride coating, or a combination thereof.

[0087] Substrates coated using such methods and coated substrates resulting from such methods can include any substrate, such as, in non-limiting examples, vehicles, personal electronic devices, packaging, three-dimensional components formed by additive manufacturing processes, and / or their components. Substrates coated using such methods and coated substrates resulting from such methods can include any substrate and packaging, where the packaging includes metal cans and / or integral aerosol cans and / or tubes, and / or the packaging is food and / or beverage packaging.

[0088] The coating composition prepared according to the present disclosure can be used to manufacture a coating composition that is substantially / essentially / completely free of catalytic tin.

[0089] Although examples of the present disclosure have been described above for purposes of illustration, it will be apparent to those skilled in the art that various changes in the details of the present disclosure can be made without departing from the present disclosure as defined in the appended claims.

[0090] Example

[0091] The following examples are intended to illustrate the present disclosure and should not be construed as limiting the present disclosure in any way.

[0092] Polymer Test Method

[0093] Unless otherwise specified, the following test methods are used to analyze the polymers.

[0094] Solid Weight % : Unless otherwise specified, the solid weight percentage is calculated as follows: Accurately weigh (about one gram) the sample and place it in an aluminum dish of known mass. Pipette a few grams of acetone onto the sample to dilute the material and facilitate the evaporation of the solvent from the aluminum dish when heated. Place the sample in a forced-air oven (Type IIA or Type IIB and meeting the specifications outlined in ASTM E145). Heat the sample for 2 hours under forced-air conditions at 150 °C. Then reweigh the sample. Compare the mass after heating with the original mass of the sample to determine the solid weight percentage of the sample.

[0095] Molecular Weight: Unless otherwise specified, the molecular weight is determined by gel permeation chromatography according to ASTM D6579-11 ("Standard Practice for Determination of Molecular Weight Averages and Molecular Weight Distribution of Hydrocarbon, Rosin, and Terpene Resins by Size Exclusion Chromatography"), using a UV detector at 254 nm (nanometers) and an un-stabilized THF solvent. The retention time marker is toluene, and the sample concentration is 2 mg / ml (milligrams per milliliter). The molecular weight is reported as Mn (number average molecular weight), Mw (weight average molecular weight), and PDI (polydispersity index), and is calculated using the following equations:

[0096] PDI = Mw / Mn

[0097] Acid Value (AV) : Unless otherwise specified, the AV is determined by titration with 0.1 M potassium hydroxide in methanol (KOH) solution. The sample (0.1 g (grams)) is accurately weighed into a conical flask and dissolved in 25 ml (milliliters) of tetrahydrofuran containing a phenolphthalein indicator using stirring and gentle heating to 50 °C. The solution is then cooled to room temperature and titrated with 0.1 M potassium hydroxide in methanol solution. The acid value is expressed in mg KOH / g and is calculated using the following equation:

[0098] Acid value = Volume of KOH solution (ml) × Molar concentration of KOH solution (M) × 56.1 / Weight of solid sample (g)

[0099] Hydroxyl Value (OHV) : The hydroxyl value is the number of mg of KOH equivalent to the hydroxyl groups in 1 g of material. Unless otherwise specified, the OHV is determined by the following method: The sample (0.13 g) is accurately weighed into a conical flask. The resin sample is dissolved in 20 ml of tetrahydrofuran, 10 ml of a 0.1 M tetrahydrofuran solution of 4-(dimethylamino)pyridine, and 5 ml of a 9 volume % acetic anhydride in tetrahydrofuran solution using stirring and gentle heating to 50 °C. After 5 minutes, 10 ml of an 80 volume % aqueous tetrahydrofuran solution is added. After an additional 15 minutes, 10 ml of tetrahydrofuran is added, and the solution is titrated with 0.5 M potassium hydroxide in ethanol solution (KOH). A blank sample without resin is also run. The resulting hydroxyl number is expressed in mg KOH / g and is calculated using the following equation:

[0100] Hydroxyl value = (V2 - V1) × Molar concentration of KOH solution (M) × 56.1 / Weight of solid sample (g)

[0101] Where V1 is the volume of the KOH solution (ml) for the test sample, and V2 is the volume of the KOH solution (ml) for the blank sample.

[0102] Isocyanate (NCO) Equivalent: Unless otherwise specified, the NCO equivalent is determined using ASTM D1638-74 (Standard Method for Testing Isocyanate Raw Materials for Polyurethane Foams), as revised herein: Prior to testing a sample, prepare a dibutylamine solution of 78 g of dibutylamine (available from Sigma Aldrich) in 4 liters of N-methyl-2-pyrrolidone (available from Fisher Scientific). Accurately weigh a sample weighing between 1 g and 2 g into a flask. React the sample with 33 ml of dibutylamine to form a substituted urea. Then back-titrate the excess dibutylamine with an isopropanol solution of 0.2 N hydrochloric acid (available from Fisher Scientific (Ricca)). The amount of hydrochloric acid used for back-titrating the excess dibutylamine is used to calculate the NCO equivalent of the original sample.

[0103] Example 1 Polyester Coating Composition

[0104] Prepare a coating composition, the first coating of which comprises a film-forming polyester produced using a catalyst system as described in the present disclosure, and a topcoat.

[0105] Preparation of Polyester Polymer (Polymers 1 to 3)

[0106] Prepare a polyester prepolymer (prepolymer) using the materials listed in Table 1. Add these materials batchwise to a vessel equipped with a steam tower, a distillation head, and a condenser (with a receiving vessel). While continuously stirring at 400 revolutions per minute (rpm) and under a nitrogen purge of 0.5 SCFH (standard cubic feet per hour), raise the batch temperature to 180 °C. When the temperature of the distillate has dropped below 90 °C, raise the batch temperature to 220 °C in 10 °C steps every 30 minutes.

[0107] Once the reaction temperature reaches 220 °C, check the acid value (AV) of the polymer until the AV drops below 20. When AV < 20, pour the prepolymer into three separate flasks for producing polymers 1 to 3. Analyze the prepolymer properties as shown in Table 2.

[0108] Table 1 - Polyester Prepolymer (Prepolymer)

[0109]

[0110]

[0111] 1 Available from LyondellBasell

[0112] 2 Available from Baichuan Chemical Co., Ltd.

[0113] 3Available from Mitsubishi Chemical Corp.

[0114] 4 Available from Arkema

[0115] 5 Available from Invista

[0116] Table 2 - Prepolymer Properties

[0117] Final Properties Prepolymer Final Resin Solid % 98.74 Mn 2677 Mw 5263 PDI 2.0 AV 18.93 OHV 41.48

[0118] A catalyst premix (premix) was prepared using a 1:1 molar equivalent ratio of a titanium catalyst and a bismuth catalyst, respectively. Under a nitrogen atmosphere, 27.0 mL of titanium(IV) butoxide (CAS: 5593-70-4, as supplied by Sigma-Aldrich) (TBT) and 50.0 mL of bismuth neodecanoate (CAS: 34364-26-6, as supplied by American Elements) were added to a 4-ounce wide-mouth bottle. The premix was stirred with a spatula for 5 minutes to ensure thorough mixing. During mixing, the wide-mouth bottle was observed to be slightly warm. Then a lid with a paraffin film was installed around the lid. The premix was used within one week after preparation.

[0119] Polyester polymers (Polymers 1 to 3) were prepared using a prepolymer and the materials shown in Table 3. The prepolymer was poured into three separate flasks. Each flask was attached with a steam tower, a distillation head, and a condenser with a receiving vessel. The catalyst was added to the flask in the amounts specified in Table 3. The batch was heated to 220 °C, and AV samples were taken to monitor the reaction progress.

[0120] Table 3 - Polymers 1 to 3

[0121]

[0122]

[0123] 6 A mixture of C8 and C9 hydrocarbons, available from ExxonMobil

[0124] 7 Propylene glycol monomethyl ether acetate, available from Dow Chemical

[0125] 8 Available from Sigma-Aldrich

[0126] Figure 1Graphs of AV vs. reaction time for the prepolymer and polymers 1 to 3 are shown. As shown, polymer 2 prepared using the premix has the fastest reaction rate as monitored by residual AV. Polymer 3 prepared using the catalyst system disclosed herein, where the components are not premixed but added separately, proceeds at the second fastest rate. Polymer 1 has the slowest reaction rate with TBT.

[0127] The properties of polymers 1 to 3 are shown in Table 4. As shown in Table 4, the catalyst systems disclosed herein are used to successfully produce polyester resins. Polymers using the catalyst systems as disclosed herein are used to successfully produce polyester resins, with a shorter reaction time compared to using a single catalyst.

[0128] Table 4 - Properties of Polymers 1 to 3

[0129] Polymer Properties Polymer 1 Polymer 2 Polymer 3 Final Resin Solid % 64.38 70.08 62.62 Mn 5306 5900 4454 Mw 15265 17467 11227 PDI 2.9 3.0 2.5 AV 2.14 2.53 2.17 OHV 21.60 23.15 22.83

[0130] Preparation and Properties of Polyester Coating (Coatings 1 to 6)

[0131] Grinding pastes 1 to 6 are prepared by adding polymers 1 to 3 to separate 1-quart unlined metal cans and removing the can lids. Pigments are slowly added while stirring the resin with a flat stirring blade. A solvent blend is added to maintain an appropriate viscosity to allow mixing. Once the full pigment load is added, 200 grams of ZIRCOA ceramic beads (2 mm) are added. The grinding paste is stirred at high speed for about 45 minutes until a Hegman fineness of 7.0 is achieved using ASTM D1210-96 testing. (Standard test method for determining the dispersion fineness of a pigment-vehicle system using a Hegman-type gauge). An ice-water bath is used during the grinding process to control the temperature. The resulting paste is screened through a metal wire mesh screen to remove the ZIRCOA beads, collected in a tared 1-pint unlined metal can and reweighed.

[0132] Table 4 - Abrasive Paste 1 to 6

[0133]

[0134] 9 Aluminum silicate (hydrated), available from KAMIN LLC

[0135] 10 Strontium aluminum polyphosphate hydrate, available from HEUBACH

[0136] 11 Titanium dioxide, available from CRISTAL GLOBAL

[0137] 12 Magnesium oxide, available from MARTIN MARIETTA MAGNESIA SPECIALTY LLC

[0138] 13 Silica, available from GRACE

[0139] 14 Silica, available from Evonik Industries

[0140] 15 50:50 weight ratio solvent blend of Solvesso 100 aromatic solvent, available from Exxon: Butyl Cellosolve (2 - butoxyethanol)

[0141] To prepare Coatings 1 to 6, the remaining liquid components shown in Table 5 were added to Abrasive Pastes 1 to 6. The mixture was stirred with a Cowles blade for 5 minutes, and then Halox 650 was added to each sample with stirring. The compositions (Coatings 1 to 6) were mixed for 10 minutes. The Hegman fineness was checked using the test method described in ASTM D1210.

[0142] Table 5 - Coatings 1 to 6

[0143]

[0144]

[0145] 16 Epoxy resin, acid value = 95, available from PPG

[0146] 17 Melamine - formaldehyde resin, available from ALLNEX

[0147] 18 Dibutyltin dilaurate, available from Reaxis Inc.

[0148] 19 Hyperbranched hydrocarbon polymer, available from Baker Hughes

[0149] 20 Acrylic homopolymer, weight - average molecular weight of about 10,000, available from PPG

[0150] 21 MEKO - capped HMDI isocyanate, available from Vencorex Chemicals

[0151] 22 50:50 solvent blend of Solvesso 100: Butyl Cellosolve

[0152] 232-Benzothiazolylthiotetradecanoic acid, available from ICL / HALOX

[0153] Coatings 1 to 6 were applied to 4-inch × 6-inch hot-dip galvanized (HDG) steel sheets pre-coated with Bonderite 1421 (available from Precoat Steel); the metal had a thickness of 0.015 inches. Coatings 1 to 6 were applied to the panels using a #10 wire-wound rod, resulting in a dry film thickness of 5 to 7 microns after curing. The coated panels were cured in an Aalborg oven available from Aalborg Company, Inc. The panels were placed in the oven, held at 540°F for 30 seconds, removed, and quenched in water.

[0154] The resistance to methyl ethyl ketone (MEK) double rub was evaluated on the cured Coatings 1 to 6 using the following method. A 2-inch × 2-inch WYPALL disposable wipe was wetted with MEK and then manually rubbed back and forth across the same point on the coated panel. A single double rub was counted as a back-and-forth movement. The MEK double rub performance was reported as the number of double rubs before coating breakthrough.

[0155] As shown in Table 6, the cured film panels with Coatings 1 to 6 all had a certain degree of MEK resistance. Coatings 3 to 4 prepared with the polymer 2 with shortened reaction time using the premix had similar MEK resistance to Coatings 1 to 2 of the polymer 1 with the longest reaction time using only TBT.

[0156] Table 6 - Coatings 1 to 6

[0157]

[0158] Preparation and Properties of Coatings 1 to 6 and Topcoat

[0159] An additional set of panels prepared with Coatings 1 to 6 coated and cured as described above were coated with DURASTAR UC Fox Gray BR5A117B available from PPG. The topcoat was applied using a #30 wire-wound rod, resulting in a dry film thickness of 18 to 20 microns after curing. The topcoat was cured using the same oven conditions as those used for curing Coatings 1 to 6.

[0160] The boiling water adhesion test was evaluated on panels coated with Coatings 1 to 6 and a topcoat. The coated panels were initially tested, and a second set of coated panels was allowed to age at ambient temperature for one month before testing. The boiling water adhesion test was conducted as follows: The panel was scored using a 2 millimeter (mm) crosscut guide available from KTA-Tator, Inc. for adhesion testing. Eleven initial cuts were made using the guide; then the guide was rotated and eleven more cuts were made in the same area, resulting in 100 (2 mm x 2 mm) crosshatch squares. Then, using a 2-pound ball punch on a Gardner impact tester PF-1120 available from Byk-Gardner, the crosshatched portion of the panel was reverse impacted (impacted from the reverse side) from the coated side of the panel. The inch-pound ("in-lb") setting was determined by the specification of the coated metal substrate. For steel, the in-lb setting was 3,000 times the specification of the substrate (in inches). For this substrate, the steel substrate specification was 0.015 inches and the in-lb setting was 45. After crosshatching and reverse impact, the panel was placed in boiling water for thirty minutes, patted dry and immediately the adhesion was evaluated using SCOTCH brand 610 tape according to ASTM D3359-97 (Standard Test Method for Measuring Adhesion by Tape Test).

[0161] As shown in Table 7, the boiling water adhesion performance of all the panels was similar. Coatings 3 to 4 (Polymer 3) with the fastest polymerization rate made using a premix and Coatings 5 to 6 (Polymer 2) with the second fastest polymerization rate made using a catalytic system, where the catalyst, TBT and bismuth neodecanoate were added separately, had the same performance as Coatings 1 to 2 using Polymer 1 with the slowest polymerization rate and TBT.

[0162] As shown in Table 7, the polyester polymers produced using the catalytic systems disclosed herein have shortened the polymerization reaction time without sacrificing the performance of the coatings prepared using these polymers.

[0163] Table 7 - Boiling Water Adhesion of Panels Made with Coatings 1 to 6 and Topcoat

[0164]

[0165] Example 2 Polyurethane Coating Composition

[0166] The coating composition was prepared using a polyurethane coating system with the catalysts or catalyst mixtures described in the present disclosure. Preparation of Polyurethane Polymer (Polymers 4 to 5)

[0167] The polyurethane polymers (Polymers 4 to 5) were prepared using the tin catalyst (Reaxis C218) or catalyst system (premix) as disclosed herein and the components shown in Table 8. The tin catalyst in Polymer 4 and the premix in Polymer 5 were added on an equimolar basis.

[0168] For Polymers 4 to 5, the materials in Feed 1 were added to a four-necked reaction flask equipped with a stirrer, inlet, thermometer, and condenser. After the exotherm subsided, the temperature was raised to 80 °C. The NCO equivalent was tracked until the reaction stopped. The reaction was cooled to 50 °C. Feed 2 was added and the reaction exothermed. Once the exotherm subsided, the reaction was maintained at 65 °C until the NCO peak at 2260 cm-1 in the IR spectrum was no longer present. The aqueous dispersion was produced by adding Charge 3 and Charge 4.

[0169] As shown in Table 8, Polymer 5 produced using the premix catalyst reached the desired NCO equivalent of Feed 1 within 2 hours, with a shorter reaction time compared to the tin catalyst (Polymer 4).

[0170] The premix catalyst system of the present disclosure successfully formed aqueous polyurethanes.

[0171] Table 8 - Polymers 4 to 6

[0172]

[0173] 24 Poly(THF) polyol, available from BASF

[0174] 25 Available from Jiangxi Nancheng Hongdu Chemical

[0175] 26 Available from Vencorex Chemicals

[0176] 27 Available from Univar Solutions

[0177] 28 Dibutyltin dilaurate, available from Reaxis Inc. 29 Available from BASF

[0178] Preparation and Properties of Polyurethane Coating (Coatings 7 to 8)

[0179] Coatings 7 and 8 were prepared using Polymers 4 to 5 and an isocyanate crosslinker (EHW8224, available from PPG) according to the weight mixing ratios shown in Table 9.

[0180] The coating was applied to the electrophoretic panel (cold rolled steel with ED7100 electrocoat paint, available from ACT Test Panels LLC, Hilldale, MI) using an 8 mil gap drawdown bar, flashed for 10 minutes at ambient temperature, and then baked at 60 °C for 45 minutes.

[0181] After aging the cured panels at room temperature for 7 days, their performance was evaluated by measuring the MEK double rub resistance. The MEK solvent resistance was tested on the cured coating composition using the following procedure. The test panel was placed on a flat, rigid surface. Two sterile gauze pads were stacked one on top of the other and then attached above the ball end of a one-pound round head hammer. The gauze was secured tightly in place with an elastic rubber band so that four layers of gauze were fixed to the end of the hammer and there were no wrinkles. The pads were initially saturated with MEK; the pads were re-saturated every 25 double rubs. Immediately after saturation with the solvent, the pads were rubbed over the test area using a 2-inch to 4-inch back-and-forth stroke. The weight of the hammer controlled the downward pressure; no downward or upward pressure was applied to the hammer handle. The back-and-forth motion was continued, with one "double rub" for each forward and backward movement. The double rub test was continued until the bare substrate was exposed in the center of the rubbed strip or until 100 double rubs were completed without the bare substrate being exposed. The MEK double rub resistance was reported as the higher of; the number of double rubs at which the bare substrate was exposed, or 100 double rubs completed without the substrate being exposed. The gauze was removed and replaced between testing each individual sample.

[0182] As shown in Table 9, the MEK rub resistance of the panel coated with Coating 8 using Polymer 5 with the catalyst system of the present disclosure matched the MEK rub resistance of the panel coated with Coating 7 using Polymer 4 with a tin catalyst.

[0183] The polymers produced using the catalytic systems disclosed herein were used to successfully produce polyurethane polymers. The polymers produced using the catalytic systems disclosed herein have reduced the reaction time for forming the polymers without sacrificing the coating properties as compared to the polymers formed using a tin catalyst.

[0184] Table 9 - Coatings 7 to 8

[0185] Polyurethane Coating Coating 7 Coating 8 Polymer 4 5.00 Polymer 6 5.00 EHW8224 2.11 2.10 Properties of Cured Coating System (7 - day Aging) MEK Double Rub 100 100

[0186] 21 Isocyanate, available from PPG.

Claims

1. A coating composition comprising a film-forming polymer formed from a reaction mixture, the reaction mixture comprising a catalyst system, the catalyst system comprising: a first catalyst comprising titanium, zirconium, or a combination thereof; and a second catalyst comprising bismuth, aluminum, zirconium, or a combination thereof; wherein the metal in the first catalyst is different from the metal in the second catalyst.

2. The coating composition according to claim 1, wherein the first catalyst comprises titanium, such as Ti(OR 1 )4, wherein R 1 is an alkyl or aryl group, such as where R 1 is a C3-C20 alkyl group, such as where R 1 is n-butyl, such as tetrabutyl titanate, or the first catalyst comprises zirconium, such as Zr(OC(O)R 2 )3, wherein R 2 is an alkyl or aryl group, and the second catalyst comprises bismuth, such as Bi(OC(O)R 3 )3, wherein R 3 is an alkyl or aryl group, such as a C5-C20 alkyl group, such as where R 3 is neodecyl, such as bismuth neodecanoate, or the second catalyst comprises aluminum, such as Al(OC(O)R 4 )3, wherein R 4 is an alkyl or aryl group, or the second catalyst comprises zirconium, such as Zr(OC(O)R 5 )3, wherein R 5 is an alkyl or aryl group.

3. The coating composition according to any one of the preceding claims, wherein the first catalyst comprises titanium, such as tetrabutyl titanate, and the second catalyst comprises bismuth, such as bismuth neodecanoate.

4. The coating composition according to any one of the preceding claims, wherein the film-forming polymer comprises polyester and / or polyurethane.

5. A coating composition comprising a polyester and / or polyurethane film-forming polymer formed from a reaction mixture, the reaction mixture comprising a catalyst system, the catalyst system comprising: a first catalyst comprising titanium; and a second catalyst comprising bismuth.

6. The coating composition according to claim 4 or claim 5, wherein the polyester comprises the reaction product of a polyacid or its ester or anhydride with a polyol, and / or the polyester comprises a hydroxyl functional group and / or a carboxyl functional group.

7. The coating composition according to any one of claims 4 to 6, wherein the polyurethane comprises the reaction product of a polyol and a polyisocyanate, and / or the polyurethane comprises a hydroxyl functional group.

8. The coating composition according to any one of the preceding claims, wherein the first catalyst and the second catalyst are premixed before being added to the reaction to form the film-forming polymer.

9. The coating composition according to any one of the preceding claims, wherein based on the total weight of the catalyst system, the catalyst system comprises 3 parts by weight to 96 parts by weight of the first catalyst and 4 parts by weight to 97 parts by weight of the second catalyst.

10. The coating composition according to any one of the preceding claims, wherein the total weight of the catalyst system does not exceed 2% by weight based on the resin solids of the film-forming polymer.

11. The coating composition according to any one of the preceding claims, wherein the coating composition further comprises a crosslinking agent, such as an aminoplast or an isocyanate.

12. The coating composition according to any one of the preceding claims, wherein the film-forming polymer and / or the coating composition is substantially free of, essentially free of, and / or completely free of catalytic tin.

13. The coating composition according to any one of the preceding claims, wherein the coating composition is a liquid coating composition, such as a solvent-based coating composition or a water-based coating composition, or a powder coating composition, and / or the coating composition is a one-component coating composition, and / or the coating composition is a multi-component coating composition, wherein the resin is in one component and the crosslinking agent is thus in another component.

14. A method for coating a substrate, which comprises applying a first coating comprising the coating composition according to any one of claims 1 to 13 to at least a part of the substrate, and optionally applying one or more additional coatings to at least a part of the first coating, such as wherein the one or more additional coatings comprise the coating composition according to any one of claims 1 to 13, a silicone-modified polyester coating composition, a polyvinylidene fluoride coating composition, or a combination thereof.

15. A substrate at least partially coated with the coating composition according to any one of claims 1 to 13.

16. The substrate according to claim 15, wherein the substrate comprises plastic, such as polycarbonate, glass, wood, or metal or metal alloy, such as aluminum or steel, such as in the form of a metal sheet or a metal coil.

17. The substrate according to claim 15 or claim 16, wherein the substrate comprises at least one additional coating, such as wherein the one or more additional coatings comprise the coating composition according to any one of claims 1 to 13, a silicone-modified polyester coating, a polyvinylidene fluoride coating, or a combination thereof.

18. The substrate according to any one of claims 15 to 17, wherein the substrate comprises a vehicle, a personal electronic device, a package, a three-dimensional component formed by an additive manufacturing process, and / or a component thereof.

19. The package according to claim 18, wherein the package comprises a metal can and / or an integral aerosol can and / or a tube, and / or the package is a food package and / or a beverage package.

20. Use of the composition according to any one of claims 1 to 13 for preparing a coating composition comprising a film-forming polymer that is substantially / essentially / completely free of catalytic tin.

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