Coating compositions comprising a styrene maleimide copolymer

Abstract

Disclosed herein are coating compositions comprising: (a) a resin comprising an epoxy-containing compound; (b) an amine; and (c) a styrene-maleimide copolymer, wherein the coating composition comprises a liquid. Also disclosed are methods for coating a substrate. Also disclosed are coated substrates.

Description

COATING COMPOSITIONS COMPRISING A STYRENE MALEIMIDE COPOLYMERCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application Serial No. 63 / 620,313, filed January 12, 2024, entitled “Coating Compositions Comprising A Styrene Maleimide Copolymer”, which is incorporated herein in its entirety.FIELD

[0002] The present disclosure is directed to coating compositions comprising a styrene maleimide copolymer.BACKGROUND

[0003] Coating compositions comprising film-forming polymers have been widely applied to, for example, appliances, automobiles, aircrafts, and the like.SUMMARY

[0004] Disclosed herein are coating compositions comprising: (a) a resin comprising an epoxy-containing compound; (b) an amine; and (c) a styrene-maleimide copolymer, wherein the coating composition comprises a liquid.

[0005] Also disclosed are methods for coating a substrate comprising: applying a coating composition disclosed herein to a surface of the substrate; and curing the coating composition.

[0006] Also disclosed are substrates comprising a coating formed from a coating composition disclosed herein on a surface of the substrate.Resin Comprising an Epoxy-Containing Compound

[0007] As stated herein above, the liquid coating composition of the present disclosure comprises a resin comprising an epoxy-containing compound. The epoxy-containing compound may comprise a monoepoxide and / or a polyepoxide. As used herein, a “monoepoxide” refers to a compound comprising one epoxide functional group. As used herein, a “polyepoxide” refers to a compound comprising more than one epoxide functional group.

[0008] Suitable monoepoxides include monoglycidyl ethers of alcohols and phenols, such as phenyl glycidyl ether, n-butyl glycidyl ether, cresyl glycidyl ether, isopropyl glycidyl ether, glycidyl versatate, for example, CARDURA E, commercially available from Shell Chemical Co., and / or glycidyl esters of monocarboxylic acids such as glycidyl neodecanoate.

[0009] Suitable polyepoxides include polyglycidyl ethers of Bisphenol A, such as EPON 828, solid EPON resins, such as EPON 1001 and EPON 1007, and polyglycidyl ethers of Bisphenol F diepoxides, such as EPON 862, all of which are commercially available from Hexion Specialty Chemicals, Inc. Other suitable poly epoxides include polyglycidyl ethers of polyhydric alcohols, polyglycidyl esters of polycarboxylic acids, polyepoxides that are derived from the epoxidation of an olefinically unsaturated alicyclic compound, polyepoxides that are derived from the epoxidation of an olefinically unsaturated alicyclic compound, polyepoxides that are derived from the epoxidation of an olefinically unsaturated nonaromatic cyclic compound, polyepoxides containing an oxyalkylene group in the epoxy molecule, and epoxy novolac resins. Still other non-limiting epoxy compounds include epoxidized Bisphenol A novolacs, epoxidized phenolic novolacs, epoxidized cresylic novolac, isosorbide diglycidyl ether, 1 ,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, triglycidyl p- aminophenol, triglycidyl p-aminophenol bismaleimide, triglycidyl isocyanurate, tetraglycidyl 4,4’ -diaminodiphenylmethane, and tetraglycidyl 4,4’-diaminodiphenylsulphone, and / or epoxy resins such as Araldite, commercially available from Huntsman,, SPI 7001 TBA 70 (commercially available from Arnette Polymers, LLC), and D.E.R. 431, 438, and 331, all commercially available from Olin).

[0010] The epoxy-containing compound may comprise a functional group in addition to the epoxide functional group(s). For example, the additional functional group may comprise a hydroxide functional group, a silane functional group, a sulfide functional group, and / or a (meth)acrylate functional group.

[0011] The epoxy-containing compound may be, for example, an epoxy-dimer acid adduct. The epoxy-dimer acid adduct may be formed as the reaction product of reactants comprising a diepoxide compound (such as a polyglycidyl ether of Bisphenol A) and a dimer acid (such as a C36 dimer acid). The epoxy-containing compound may also comprise a carboxyl-terminated butadiene-acrylonitrile copolymer modified epoxy-containing compound. The epoxy-containing compound may also comprise an epoxy-containing acrylic, such as glycidyl methacrylate.

[0012] The epoxy-containing compound may have an epoxide equivalent weight of at least 80 g / eq, such as at least 140 g / eq, such as at least 200 g / eq. The epoxy-containing compound may have an epoxide equivalent weight of no more than 2,000 g / eq, such as no morethan 1 ,000 g / eq, such as no more than 750 g / eq. The epoxy-containing compound may have an epoxide equivalent weight of 80 g / cq to 2,000 g / cq, such as 140 g / cq to 1,000 g / cq, such as 200 g / eq to 750 g / eq. As used herein, the “epoxide equivalent weight” refers to the weight of material in grams containing one stoichiometric equivalent of an epoxy functional group. The epoxide equivalent weight may be determined, for example, by titration of a sample using a Metrohm 808 or 888 Titrando, using a sample 0.06 g per 100 g / eq of predicted epoxy equivalent weight and dissolving the sample in 20 mL of methylene chloride or tetrahydrofuran and then adding 40 mL glacial acetic acid and one gram of tetraethylammonium bromide before titration with 0.1 N perchloric acid in glacial acetic acid.

[0013] The coating composition may comprise the resin comprising the epoxy-containing compound in an amount of at least 20% by weight based on total resin solids weight of the coating composition, such as at least 40% by weight. The coating composition may comprise the resin comprising the epoxy-containing compound in an amount of no more than 95% by weight based on total resin solids weight of the coating composition, such as no more than 90% by weight. The coating composition may comprise the resin comprising the epoxy-containing compound in an amount of 20% by weight to 95 % by weight based on total resin solids weight of the coating composition, such as 40% by weight to 90% by weight.Amine

[0014] As previously stated, the coating composition disclosed herein comprises an amine. The amine may comprise a monoamine, a diamine, and / or a polyamine. As used herein, a “monoamine” refers to a compound comprising one amino functional group. As used herein, a “diamine” refers to a compound comprising more than one to two amino functional groups. As used herein, a “polyamine” refers to a compound comprising more than two amino functional groups.

[0015] The amine may comprise a primary amine and / or a secondary amine. The amine may comprise an amide. The amine may comprise a crosslinker and / or an accelerator, such as an amine-based catalyst.

[0016] Suitable monoamines include, for example, Silquest Al 100 and Silquest A 1110, both commercially available from Momentive.

[0017] Suitable polyamines include primary or secondary polyamines in which the radicals attached to the nitrogen atoms can be saturated or unsaturated, aliphatic, acyclic,aromatic, aromatic-substituted-aliphatic, aliphatic-substituted-aromatic, and / or heterocyclic. Nonlimiting examples of suitable aliphatic and acyclic diamines include 1 ,2-cthylcnc diamine, 1,2-propylene diamine, 1,8-octane diamine, isophorone diamine, propane-2, 2-cyclohexyl amine, and the like. Nonlimiting examples of suitable aromatic diamines include phenylene diamines and toluene diamines, for example, o-phenylene diamine and p-tolylene diamine. Polynuclear aromatic diamines, such as 4,4’ -biphenyl diamine, methylene dianiline, and monochloromethylene dianiline are also suitable.

[0018] Suitable aliphatic diamines include, without limitation, ethylene diamine, 1,2- diaminopropane, 1 ,4-diaminobutane, 1 ,3-diaminopentane, 1 ,6-diaminohexane, 2-methyl-l,5- pentane diamine, 2,5-diamino-2,5-dimethylhexane, 2,2,4- and / or 2,4,4-trimethyl-l,6-diamino- hexane, 1,11 -diaminoundecane, 1,12-diaminododecane, 1,3- and / or 1,4-cyclohexane diamine, 1- amino-3,3,5-trimethyl-5-aminomethyl-cyclohexane, 2,4- and / or 2,6-hexahydrotoluylene diamine, 2,4’- and / or 4,4’-diamino-dicyclohexyl methane, 3,3’-dialkyl-4,4’-diamino-cyclohexyl methanes (such as 3,3’-dimethyl-4,4’-diamino-dicyclohexyl methane and / or 3,3’-diethyl-4,4’-diamino- dicyclohexyl methane), 2,4- and / or 2,6-diaminotoluene, and / or 2,4’ and / or 4,4’ -diaminodiphenyl methane. Cycloaliphatic diamines are available commercially from Huntsman Corporation (Houston, TX) under the designation of JEFFLINK, such as JEFFLINK 754. Additional aliphatic cyclic polyamines may also be used, such as DESMOPHEN NH 1520, commercially available from Covestro and / or CLEARLINK 1000 (a secondary aliphatic diamine), commercially available from Dorf Ketal. POLYCLEAR 136 (the reaction product of isophorone diamine and acrylonitrile), commercially available from BASF / Hansen Group LLC, is also suitable. Other exemplary suitable polyamines are described in U.S. Patent No. 4,046,729, 6:61- 7:26 and U.S. Patent No. 3,799,854, 3:13-50, the cited portions incorporated herein by reference. Additional polyamines may also be used, such as ANCAMINE polyamines, commercially available from Evonik. Suitable polyamides include ANCAMIDE polyamides, commercially available from Evonik. The amine may comprise a polyether functional amine, such as those available under the trade name JEFFAMINE, such as JEFF AMINE D2000, commercially available from Huntsman Corporation. The amine may comprise an amino-compound, such as an aminosilanc (for example, SILQUEST A-1120, commercially available from Momcntivc).

[0019] The coating composition may comprise the amine in an amount of at least 3% by weight based on total resin solids weight of the coating composition, such as at least 7% byweight. The coating composition may comprise the amine in an amount of no more than 60% hy weight based on total resin solids weight of the coating composition, such as no more than 45% by weight. The coating composition may comprise the amine in an amount of 3% by weight to 60% by weight based on total resin solids weight of the coating composition, such as 7% by weight to 45% by weight.Styrene-Maleimide Copolymer

[0020] The coating composition further comprises a styrene-maleimide copolymer.

[0021] The styrene maleimide copolymer may be synthesized by reacting reactants comprising a styrene-maleic anhydride copolymer or styrene-maleic anhydride partial ester resin and an amine in the presence of a non-reacting diluent, for example, at 150°C to 180°C for 2 to 3 hours to form an amide. Water may then be removed to complete the imidization to form the maleimide.

[0022] The amine may comprise, for example, a diamine comprising a primary amine and a tertiary amine.

[0023] Styrene-maleimide copolymers may include derivatives thereof, such as butadiene-styrene maleimide polymers. The styrene-maleimide copolymer may comprise additional functionality. For example, the styrene-maleimide copolymer may comprise a second tertiary amine functional group in addition to the tertiary amine functional group derived from the amine.

[0024] Suitable styrene-maleimide copolymers include copolymers of styrene and dimethyl aminopropylamine maleimide, such as SMA10001, SMA20001, SMA30001, and SMA4000I, all commercially available from Cray Valley. The styrene-maleimide copolymer may have the general structure:(I) , wherein y = 1 to 10; R1= Cl to CIO alkyl; R2= Cl to CIO alkyl; x = at least 1, such as at least 2, such as at least 3, such as at least 4, such as at least 5, such as at least 6; and n = 2-368, such as 2-184, such as 2-74, such as 2-37.

[0025] The styrene-maleimide copolymer may have a weight average molecular weight of at least 1,400 g / mol, such as at least 3,000 g / mol, such as at least 5,000 g / mol. The styrene- maleimide copolymer may have a weight average molecular weight of no more than 50,000 g / mol, such as no more than 20,000 g / mol, such as no more than 10,000 g / mol. The styrene- maleimide copolymer may have a weight average molecular weight of 1,400 g / mol to 50,000 g / mol, such as 3,000 g / mol to 20,000 g / mol, such as 5,000 g / mol to 10,000 g / mol. The weight average molecular weight (“Mw”) may be determined by gel permeation chromatography according to ASTM D6579-11 (“Standard Practice for Molecular’ Weight Averages and Molecular Weight Distribution of Hydrocarbon, Rosin and Terpene Resins by Size Exclusion Chromatography”).

[0026] The styrene-maleimide copolymer may comprise a reaction product of reactants comprising a styrene-maleic anhydride copolymer and an amine.

[0027] The styrene-maleic anhydride copolymer may comprise a reaction product comprising reactants comprising a styrene monomer and a maleic anhydride monomer. The styrene monomer and the maleic anhydride monomer may be present in a molar ratio of at least 0.1:1, such as at least 1:1, such as at least 3:1. The styrene monomer and the maleic anhydride monomer may be present in a molar ratio of no more than 6:1, such as no more than 3:1, such as no more than 1:1. The styrene monomer and the maleic anhydride monomer may be present in a molar ratio of 0.1:1 to 6:1, such as 1:1 to 3:1, such as 6:1 to 1:1.

[0028] The styrene-maleimide copolymers may comprise structural units derived from a styrene (“styrene structural units”) and structural units derived from a maleimide (“maleimide structural units”). The styrene-maleimide copolymer may have a ratio of styrene structural units to maleimide structural units of at least 0.1:1, such as at least 1:1. The styrene-maleimide copolymer may have a ratio of styrene structural units to maleimide structural units of no more than 4:1, such as no more than 3:1, such as no more than 2:1, such as no more than 1:1. Thestyrene-maleimide copolymer may have a ratio of styrene structural units to maleimide structural units of 0.1:1 to 4:1, such as 1:1 to 3: 1, such as 1:1 to 2:1, such as 0.1:1 to 1:1.

[0029] As used herein, the term “structural units,” when referring to units of a copolymer, refers to the unit of copolymer derived from the incorporation of a reactant into the copolymer.

[0030] The coating composition may comprise the styrene-maleimide copolymer in an amount of at least 2% by weight based on total resin solids weight of the coating composition, such as at least 4% by weight. The coating composition may comprise the styrene-maleimide copolymer in an amount of no more than 30% by weight based on total resin solids weight of the coating composition, such as no more than 20% by weight. The coating composition may comprise the styrene-maleimide copolymer in an amount of 2% by weight to 30% by weight based on total resin solids weight of the coating composition, such as 4% by weight to 20% by weight.Optional Materials

[0031] The coating composition of the present disclosure may optionally further comprise a corrosion inhibitor.

[0032] A suitable corrosion inhibitor that may be used includes magnesium oxide (MgO).

[0033] The MgO may comprise nano- sized MgO and / or micron- sized MgO. The particle size may be reported as average particle size by the manufacturer, or optionally, the number average particle size may be determined, for example, by visually examining a micrograph of a transmission electron microscopy (“TEM”) image, as described below.

[0034] The MgO may comprise a micron sized powder, or a dispersion thereof, having a number average particle size of at least 0.5 micron, such as at least 1 micron. The MgO may comprise a micron sized powder, or dispersion thereof, having a number average particle size of no more than 50 microns, such as no more than 30 microns. The MgO may comprise a micron sized powder, or dispersion thereof, having a number average particle size of 0.5 microns to 50 microns, such as 1 micron to 30 microns.

[0035] Alternatively, or in addition, the MgO may comprise a nano sized powder, or dispersions thereof. The MgO may comprise a nano sized powder having a number average particle size of at least 10 nm. The MgO may comprise a nano sized powder having a number average particle size of no more than 499 nm, such as no more than 100 nm. The MgO maycomprise a nano sized powder having a number average particle size of 10 nm to 499 nm, such as 10 nm to 100 nm.

[0036] Number average particle size reported herein may be determined by visually examining a micrograph of a transmission electron microscopy (“TEM”) image, measuring the diameter of the particles in the image, and calculating the average primary particle size of the measured particles based on magnification of the TEM image. One of ordinary skill in the art will understand how to prepare such a TEM image and determine the primary particle size based on the magnification. The primary particle size of a particle refers to the smallest diameter sphere that will completely enclose the particle. As used herein, the term “primary particle size” refers to the size of an individual particle as opposed to an agglomeration of two or more individual particles.

[0037] Particle size as reported herein refers to the MgO particle size prior to incorporation into the coating composition. Various coating preparation methods may result in the MgO particles agglomerating, which could increase average particle size, or shearing or other action that can reduce average particle size. MgO particles are commercially available from a number of sources, such as NANO-MgO from U.S. Research Nanomaterials, Inc. (TX, USA), such as MAGLITE Y from The Hallstar Company (IL, USA), and the like.

[0038] The MgO may comprise ultrafine MgO particles. As used herein, the term “ultrafine” particles refers to particles that have a B.E.T. specific surface area of at least 10 square meters per gram (m2 / g), such as 30 m2 / g to 500 m2 / g, such as 30 m2 / g to 100 m2 / g, such as 40 m2 / g to 80 m2 / g, such as 40 m2 / g to 60 m2 / g, such as 80 m2 / g to 250 m2 / g. As used herein, “B.E.T. specific surface area” refers to a specific surface area determined by nitrogen adsorption according to the ASTM D3663-78 standard based on the Brunauer-Emmett-Teller method described in the periodical “The Journal of the American Chemical Society,” 60, 309 (1938).

[0039] The MgO may comprise MgO particles having a calculated equivalent spherical diameter of no more than 200 nm, such as no more than 100 nm, such as 5 nm to 50 nm. As will be understood by those skilled in the art, a calculated equivalent spherical diameter may be determined from the B.E.T. specific surface area according to the equation:Diameter (nm) = 6000(B.E.T. (m2 / g))(density (g / cm3))

[0040] The shape (or morphology) of the MgO particles may vary. For example, the MgO particles may comprise particles having generally spherical morphologies and / or the MgO particles may be cubic, platy, polyhedric, or acicular (elongated or fibrous). The particles may be covered completely in a polymeric gel, not covered at all in a polymeric gel, or covered partially with a polymeric gel. Covered partially with a polymeric gel means that at least some portion of the particle has a polymeric gel deposited thereon, which, for example, may be covalently bonded to the particle or merely associated with the particle.

[0041] The MgO may comprise one or more different types of MgO particles. For example, the MgO may comprise MgO nanosized particles and MgO micron sized particles.

[0042] Amino acid(s) are also suitable corrosion inhibitors. Amino acids will be understood by those skilled in the art as compounds having both acid and amine functionality, with side chains specific to each amino acid. The amino acid may be monomeric or oligomeric, including a dimer. When an oligomeric amino acid is used, the molecular weight, as determined by GPC, of the oligomer may be less than 1000.

[0043] Particularly suitable amino acids are histidine, arginine, lysine, cysteine, cystine, tryptophan, methionine, phenylalanine and tyrosine. Mixtures may also be used. The amino acids can be either L- or D- enantiomers or mixtures thereof. Amino acids can be purchased, for example, from Sigma Aldrich, Thermo Fisher Scientific, Hawkins Pharmaceutical, or Ajinomato.

[0044] An azole may also be a suitable corrosion inhibitor. Examples of suitable azoles include benzotriazoles such as 5-methyl benzotriazole, tolyltriazole, 2,5- dimercapto-1,3,4- thiadiazole, 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, l-phenyl-5- mercaptotetrazole, 2-amino-5-mercapto-l,3,4-thiadiazole, 2-mercapto-l-methylimidazole, 2- amino-5-ethyl-l,3,4- thiadiazole, 2-amino-5-ethylthio-l,3,4-thiadiazole, 5-phenyltetrazole, 7h- imidazo(4,5- d)pyrimidine, and 2-amino thiazole. Salts of any of the foregoing, such as sodium and / or zinc salts, are also suitable. Additional azoles include 2-hydroxybenzothiazole, benzothiazole, 1- phenyl-4-methylimidazole, and l-(p-tolyl)-4-methlyimidazole. A suitable azole-containing product is commercially available from WPC Technologies, as HYBRICOR 204, Hybricor 204S, and Inhibicor 1000. Mixtures of azoles may also be used.

[0045] Lithium-based compounds are also suitable corrosion inhibitors. Lithium-based compounds can be used, for example, in salt form, such as an organic or inorganic salt.Examples of suitable lithium salts include but are not limited to lithium carbonate, lithium phosphate, lithium sulphate, and / or lithium tetraborate. Other lithium compounds include but arc not limited to lithium silicate, including lithium orthosilicate (LLSiCL), lithium metasilicate, lithium zirconate, and lithium-exchanged silica particles. Coating compositions of the present disclosure may also exclude lithium compounds, such as lithium salt and / or lithium silicate; that is, the coating compositions of the present disclosure may be substantially free, essentially free, or completely free of any of the lithium compounds described above.

[0046] The coating composition may optionally further comprise a polymer in addition to the epoxy-containing compound, the amine, and the styrene-maleimide copolymer. The additional polymer may comprise an acrylic, a polyester, an epoxy polymer in addition to the epoxy resin, and / or a polyurethane.

[0047] The coating composition may optionally further comprise an additive. Suitable additives include but are not limited to water, solvents, such as organic solvents, colorants, fillers, including but not limited to clays, inorganic minerals, abrasion-resistant particles, antioxidants, hindered amine light stabilizers, UV light absorbers and stabilizers, surfactants, flow and surface control agents, thixotropic agents, reactive diluents, driers, catalysts, reaction inhibitors, adhesion promoting materials, such as acids and acid derivatives, phosphatized epoxy, and / or silanes, such as epoxy silanes.

[0048] As used herein, “colorants” refers to any substance that imparts color and / or opacity and / or other visual effect to the composition.

[0049] The coating composition of the present disclosure may be substantially free, essentially free, or completely free of a chromium (Vl)-containing material.Compositions, Systems and Methods

[0050] The coating compositions disclosed herein are formulated as liquid compositions.

[0051] The coating composition may comprise a molar ratio of epoxy functional groups from the epoxy-containing compound to amine functional groups from the amine of at least 5:1, such as at least 3:1. The coating composition may comprise a molar ratio of epoxy functional groups from the epoxy-containing compound to amine functional groups from the amine of no more than 1:5, such as no more than 1:3. The coating composition may comprise a molar ratio of epoxy functional groups from the epoxy-containing compound to amine functional groups from the amine of 5:1 to 1:5, such as 3:1 to 1:3.

[0052] The coating composition of the present disclosure may be provided as a multicomponent coating composition, such as a two-component coating composition. As used herein, the term “two-component” or “2K” refers to a composition in which the reactive components readily associate to foim an interaction or react to form a bond (physically or chemically), i.e., cure, without activation from an external energy source, such as at ambient or slightly thermal conditions, when mixed. One of skill in the ait understands that the two components of the composition are stored separately from each other and mixed just prior to application of the composition. A first component may comprise, consist essentially of, or consist of the epoxy resin. A second component may comprise, consist essentially of, or consist of the amine. The first, second, or additional components (i.e., third component, fourth component, etc.) may comprise, or consist essentially of, or consist of corrosion inhibitors, additional polymers, and / or additives. As used with respect to the components, reference to “first,” “second,” etc. is for convenience only and does not refer to order of addition to the coating composition or the like. Furthermore, this language is not intended to be limiting and does not exclude the possibility of the coating composition comprising more than two components, such as a third or more component.

[0053] The coating compositions disclosed herein may be applied alone or as part of a coating system. Coating compositions disclosed herein may be applied directly onto the surface of a substrate or over an underlayer by any suitable coating process. Coating compositions can be deposited on substrates in a number of different ways, such as by brushes, rollers, films, pellets, pressure injectors, spray guns, and / or applicator guns. The system may comprise a number of the same or different layers and may further comprise other coating compositions such as pretreatment compositions. A coating, film, layer or the like is typically formed when a coating composition that is deposited onto the substrate is at least partially cured by methods known to those of ordinary skill in the art, e.g., coating composition may be cured under ambient conditions and may further cure using an external energy source, such as an oven or other thermal means or through the use of actinic radiation to form a coating, layer, or film. A multicomponent composition may at least partially cure at ambient conditions or slightly thermal conditions.

[0054] As used herein, “ambient conditions” generally refer to room temperature (e.g.,23 °C) and humidity conditions or temperature and humidity conditions that are typically foundin the area in which the composition is applied to a substrate, e.g., at 10°C to 32°C and 20% to 80% relative humidity.

[0055] As used herein, “slightly thermal conditions” refers to temperatures that are slightly above ambient temperature, such as 40°C to 80°C. When cured at room temperature a coating formed from one of the coating compositions of the present disclosure can cure to a tack free surface, for example, within 24 hours, within 20 hours, within 16 hours, within 12 hours, within 6 hours, or within 3 hours, from the time of mixing. The skilled person understands, however, that the time of curing varies with temperature.

[0056] Coatings formed from the coating compositions of the present disclosure may form part of a multi-layer coating system. A coating layer applied from one of the coating compositions disclosed herein may have one or more additional coating layers deposited under and / or over the coating layer. In a non-limiting example, the coating system may comprise a pretreatment layer and a coating layer formed from one of the coating compositions described herein over at least a portion of the pretreatment layer. One or more additional coating layers may be applied over at least a portion of the coating layer. Additional coating layers may comprise basecoats, color coats, monocoats, clear coats, and / or topcoats. Suitable additional coating layers include any of those known in the art, and each independently may be waterborne, solventborne, in solid particulate form (i.e., a powder coating composition), or in the form of a powder slurry. The additional coating layers may each be cured independently, or optionally applied “wet-on-wet” and cured simultaneously. As used herein, “wet-on-wet” refers to a process in which a coating, such as a clear coat, is applied over a substantially uncured different coating, such as a color coat, and both coatings are then cured simultaneously.

[0057] The coating system may optionally comprise a colorant and / or a filler as known to those skilled in the art, in any coating layer or layers, in any amount sufficient to impart a desired property, visual effect, and / or color effect.

[0058] The present disclosure is also directed to a method for coating a substrate comprising applying to at least a portion of the substrate a first coating composition comprising any of the coating compositions described herein, and optionally applying one or more additional coatings to at least a portion of the first coating, wherein the one or more additional coatings is applied from a coating composition that is the same or different than the coating composition ofthe present disclosure, such as a coating composition comprising a silicone modified polyester, a fluoropoly mcr, and / or a polyurethane.

[0059] After application to the substrate(s), the coating composition may be cured. For example, the coating composition may be allowed to cure at room temperature, and for any desired time period sufficient to at least partially cure the coating composition, such as for 1-2 hours, prior to application of an additional same or different coating layer. In another example, the composition may be allowed to fully cure at room temperature, and for any desired time period, such as for 2 weeks. The composition may be cured to form a coating, layer, or film on the substrate surface under ambient conditions or slightly thermal conditions. The coating, layer, or film may be, for example, a primer, a basecoat, a topcoat, a sealant, a gap filler, or an adhesive.Coatings

[0060] Compositions disclosed herein may be used to form coatings and the like and to provide a substrate with a coating. The coating may, in an at least partially cured state, be exposed to liquids and / or fluids, such as oils, jet oils, and hydraulic fluids. Hydraulic fluids can comprise a wide range of chemical compounds and mixtures thereof, such as oils; alcohols and poly alkylene glycols; esters such as phthalates and adipates; organophosphates; or a mixture of phosphate esters, silicones, alkylated aromatic hydrocarbons, polyalphaolefins, corrosion inhibitors and other additives.

[0061] Hydraulic fluid and / or jet oil resistance of coatings formed from the coating compositions disclosed herein may be determined, for example, by immersion of cured coated test panels in test fluids, such as MOBIL jet oil MIL-PRF-23699, hydraulic fluid MIL-PRF- 83282, or hydraulic fluid SKYDROL LD4, commercially available from Eastman, at a set temperature and duration, for example for 3 days at 71 °C, or otherwise by contact of the coating surface with the test fluid. The coatings were then tested for weight gain and / or changes in performance, such as changes in hardness, scratch resistance, and / or adhesion. The coatings formed from coating compositions comprising a resin comprising an epoxy-containing compound, an amine, and a styrene-maleimide copolymer demonstrated substantially improved resistance to jet oil and hydraulic fluids over coatings formed from coating compositions comprising an epoxy resin and amine, but no styrene-maleimide copolymer. These results were surprising and unexpected.

[0062] It was surprisingly discovered that coatings formed from the coating compositions disclosed herein provide improved hydraulic fluid resistance, hot water resistance, and adhesive properties over coatings formed from compositions that do not comprise a styrene-maleimide copolymer. These improved properties were demonstrated for both non-pigmented and pigmented coating compositions. Coatings formed from the coating compositions disclosed herein demonstrated:

[0063] (i) a percent weight gain of less than 33% after SKYDROL LD4 immersion for 3 days at 71 °C compared to weight prior to immersion, such as no more than 20%; (ii) a pencil hardness of at least H after SKYDROL LD4 immersion for 3 days at 71 °C, as measured by ASTM D3363-22, such as at least 2H;

[0064] (iii) a pencil hardness of at least H after SKYDROL LD4 immersion for 7 days at 71 °C, as measured by ASTM D3363-22, such as at least 2H;

[0065] (iv) a pencil hardness of at least H after SKYDROL LD4 immersion for 28 days at 71 °C, as measured by ASTM D3363-22, such as at least 2H; and / or

[0066] (v) a crosshatch adhesion of at least 5B after immersion in deionized water for 1 day at 71°C, as measured by ASTM D3359-17, method B.

[0067] It was also surprisingly discovered that a coating formed from a water reducible coating composition comprising epoxy resin, amine, and a styrene-maleimide copolymer demonstrated improved hydraulic fluid resistance while maintaining corrosion performance when compared to a coating formed form a water reducible coating composition that does not contain a styrene-maleimide copolymer. Coatings formed from a water reducible coating composition comprising epoxy resin, amine, and a styrene-maleimide copolymer demonstrated:

[0068] (i) a scratch resistance of greater than 900 grams after SKYDROL LD4 immersion for 14 days at 71°C, as measured by ISO1518-L2019, such as at least 1000 grams; and / or

[0069] (ii) no blisters, scribe darkening, and minimal salting after 2000 hours neutral salt spray testing, as measured by ASTM Bl 17-19.Substrates

[0070] Further disclosed herein is a substrate comprising, or consisting essentially of, or consisting of a coating on at least a portion of a surface of the substrate formed from any of the coating compositions disclosed herein.

[0071] Further disclosed herein is an article comprising, or consisting essentially of, or consisting of, a first substrate, a second substrate, and a coating formed from any of the coating compositions disclosed herein positioned therebetween.

[0072] The substrates that may be coated by the coating compositions of the present disclosure are not limited. Suitable substrates useful in the present disclosure include, but are not limited to, materials such as metals or metal alloys, ceramic materials such as boron carbide or silicon carbide, polymeric materials such as hard plastics including filled and unfilled thermoplastic materials or thermoset materials, or composite materials. Other suitable substrates useful in the present disclosure include, but are not limited to, glass or natural materials such as wood. For example, suitable substrates include rigid metal substrates such as ferrous metals, aluminum, aluminum alloys, magnesium, titanium, copper, and other metal and alloy substrates. The ferrous metal substrates used in the practice of the present disclosure may include iron, steel, and alloys thereof. Non-limiting examples of useful steel materials include cold rolled steel, galvanized (zinc coated) steel, electrogalvanized steel, stainless steel, pickled steel, zinc-iron alloy such as GALV ANNEAL, and combinations thereof. Combinations or composites of ferrous and non-ferrous metals can also be used. Aluminum alloys of the 1XXX, 2XXX, 3XXX, 4XXX, 5XXX, 6XXX, 7XXX, or 8XXX series as well as clad aluminum alloys and cast aluminum alloys of the A356, 1XX.X, 2XX.X, 3XX.X, 4XX.X, 5XX.X, 6XX.X, 7XX.X, or 8XX.X series also may be used as the substrate. Magnesium alloys of the AZ31B, AZ91C, AM60B, or EV31A series also may be used as the substrate. The substrate used in the present disclosure may also comprise titanium and / or titanium alloys of grades 1-36 including H grade variants. Other suitable non-ferrous metals include copper and magnesium, as well as alloys of these materials. The compositions disclosed herein are particularly suitable for use in various industrial or transportation applications including automotive, light and heavy commercial vehicles, marine, or aerospace. Suitable metal substrates for use in the present disclosure include those that are used in the assembly of vehicular bodies (e.g., without limitation, door, body panel, trunk deck lid, roof panel, hood, roof and / or stringers, rivets, landing gear components, and / or skins used on an aircraft), a vehicular frame, vehicular parts, motorcycles, wheels, and industrial structures and components. As used herein, “vehicle” or variations thereof includes, but is not limited to, civilian, commercial and military aircraft, and / or land vehicles such as cars, motorcycles, and / or trucks. The metal substrate also may be in the form of, for example, a sheetof metal or a fabricated part. It will also be understood that the substrate may be converted, anodized, primed, organic-coated or chromatc-coatcd, epoxy, urethane, graphite, fiberglass composite, Kevlar®, acrylics, and polycarbonates. The substrate may comprise a composite material such as a plastic or a fiberglass composite. The substrate may be a fiberglass and / or carbon fiber composite. The first and second substrates may be made of the same material or may be made of dissimilar materials. For example, a first substrate and a second substrate may be a metal and a plastic; two dissimilar plastics; a metal or a plastic and a reinforced plastic composite; or two dissimilar plastic composites.Additive Manufacturing

[0073] Coating compositions of the present disclosure may be casted, extruded, molded, or machined to form a part or a member in an at least partially dried or cured state.

[0074] The coating compositions disclosed herein may be used in any suitable additive manufacturing technology, such as three-dimensional (3D) printing, extrusion, jetting, and / or binder jetting. Additive manufacturing refers to a process of producing a part or member by constructing it in layers, such as one layer at a time.

[0075] The present disclosure is also directed to the production of structural articles, such as sound damping pads, using an additive manufacturing process, such as 3D printing. 3D printing refers to a computerized process, optionally including artificial intelligence modulation, by which materials are printed or deposited in successive layers to produce a 3D part or member, such as sound damping pads in a battery assembly. A 3D part or member may be produced by depositing successive portions or layers over a base of any spatial configuration and thereafter depositing additional portions or layers over the underlying deposited portion or layer and / or adjacent to the previously deposited portion or layer to produce the 3D printed pail or member.

[0076] It will be appreciated that the configuration of the 3D printing process, including the selection of suitable deposition equipment, depends on a number of factors such as the deposition volume, the viscosity of the composition, and the complexity of the part being fabricated. Any suitable mixing, delivery, and 3D printing equipment as known to those skilled in the art may be used. Coating compositions may be printed or deposited in any size and / or shape of droplets or extrudate, and in any patterns to produce the 3D structure.

[0077] Coating compositions as disclosed herein may be applied or deposited by any suitable 3D printing method as known to those skilled in the ail. First and second components of2K compositions may be mixed and then deposited, or the first and second components may be deposited separately, such as simultaneously and / or sequentially.

[0078] First and second components may be premixed, i.e., mixed together, prior to application, and then deposited. The mixture may be at least partially reacted or thermoset when the material is deposited; the deposited reaction mixture may react at least in part after deposition and may also react with previously deposited portions and / or subsequently deposited portions of the article such as underlying layers or overlying layers of the article.

[0079] In a non-limiting example, the first and second components may be released from their individual storage containers and pushed, such as pumped through conduits, such as hoses, to a mixer, such as a static or dynamic mixer, wherein the coating composition may be mixed for a time sufficient to homogenize the coating composition, wherein the coating composition may then be released through an outlet. The outlet may be a deposition device, such as a printing head, and / or the materials may exit the mixing unit and be pushed, such as by a pump, through a conduit, such as a hose, to the printing head. The printing head may optionally be mounted on a 3D rotational robotic arm to allow delivery of 3D print compositions to any base in any spatial configuration and / or the base may be manipulated in any spatial configuration during the 3D printing process.

[0080] Alternatively, first and second components may be deposited independently from different printing heads. The first component may be deposited from one printing head and the second component may be deposited from a second printing head. The first and second components may be deposited in any pattern such that the first and second components comprising any deposited layer can react together as well as react with underlying and / or overlying layers to produce the 3D printed pail or member.

[0081] Methods provided by the present disclosure include printing the coating composition on a fabricated pail. Methods provided by the present disclosure include directly printing parts.

[0082] Using the methods provided by the present disclosure parts can be fabricated. The entire part can be formed from one of the coating compositions disclosed herein, one or more portions of a part can be formed from one of the coating compositions disclosed herein, and / or one or more surfaces of a part can be formed from a coating composition provided by thepresent disclosure. In addition, internal regions of a part can be formed from a coating composition provided by the present disclosure.Definitions

[0083] For purposes of this detailed description, it is to be understood that the disclosure may assume alternative variations and step sequences, except where expressly specified to the contrary.

[0084] The numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard variation found in their respective testing measurements.

[0085] Also, it should be understood that any numerical range recited herein is intended to include all sub-ranges subsumed therein. 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 of equal to or less than 10.

[0086] As used herein, “including,” “containing,” and like terms are understood in the context of this application to be synonymous with “comprising” and are therefore open-ended and do not exclude the presence of additional undescribed or unrecited elements, materials, ingredients, or method steps. 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 those that do not materially affect the basic and novel characteristic(s)” of what is being described.

[0087] In addition, in this application, the use of “or” means “and / or” unless specifically stated otherwise, even though “and / or” may be explicitly used in certain instances.

[0088] As used herein, the terms “on,” “onto,” “applied on,” “applied onto,” “formed on,” “deposited on,” “deposited onto,” and the like mean formed, overlaid, deposited, or provided on, but not necessarily in contact with, a substrate surface. For example, a composition “applied onto” a substrate surface does not preclude the presence of one or more other intervening coating layers or films of the same or different composition located between the composition and the substrate surface.

[0089] As used herein, a “coating composition” refers to a composition, e.g., a solution, mixture, or a dispersion, that is capable of producing a coating on a portion of a substrate surface.

[0090] As used herein, “coating” includes films, layers, and the like.

[0091] As used herein, “polymer” refers to prepolymers, oligomers, homopolymers, and copolymers.

[0092] As used herein, the term “resin solids” refers to any film-forming polymers, crosslinkers, and / or any additional non-pigmented components, including at least the epoxy resin, the amine, and the styrene-maleimide copolymer.

[0093] As used herein, the term “film-forming polymer” refers to a polymer that is capable of forming a film upon curing.

[0094] As used herein, a “liquid” means a material having a viscosity less than 100,000 Pa*s at 25°C as measured by parallel plate rheology with a plate diameter of 25 mm, a gap of 0.5 mm, and a shear rate of 1 s’1.

[0095] As used herein, the term “accelerator” means a substance that increases the rate or decreases the activation energy of a chemical reaction in comparison to the same reaction in the absence of the accelerator. An accelerator may be either a “catalyst” (that is, without itself undergoing any permanent chemical change) or may be reactive (that is, undergoing a permanent chemical change).

[0096] As used herein, unless indicated otherwise “substantially free” means that a particular material is not purposefully added to a mixture or composition, respectively, and is present only as an impurity in a trace amount of less than 0.001% by weight based on total solids weight of the mixture or composition, respectively. As used herein, unless indicated otherwise, the term “essentially free” means that a particular material is not purposefully added to a mixture or composition and is present only as an impurity in an amount of less than 0.0001% by weight based on total solids weight of the mixture or composition, respectively. As used herein, unless indicated otherwise, the term “completely free” means that a mixture or composition, respectively, does not comprise a particular material, i.e., the mixture or composition comprises 0% by solids weight of such material.

[0097] Whereas aspects of the disclosure have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those detailscould be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed arc meant to be illustrative only and not limited as to the scope of the disclosure which is to be given the full breadth of the claims and aspects appended and any and all equivalents thereof.

[0098] In view of the foregoing description the present disclosure thus relates in particular to the following Aspects 1 - 65 without being limited thereto.ASPECTS

[0099] Aspect 1. A coating composition comprising:(a) a resin comprising an epoxy-containing compound;(b) an amine; and(c) a styrene-maleimide copolymer; wherein the coating composition comprises a liquid.

[0100] Aspect 2. The coating composition of aspect 1, wherein the epoxy-containing compound comprises a functional group in addition to the epoxy functional group, such as a hydroxide functional group, a silane functional group, a sulfide functional group, and / or a (meth)acrylate functional group.

[0101] Aspect 3. The coating composition of aspect 1 or aspect 2, wherein the epoxy- containing compound comprises an epoxide equivalent weight of at least 80 g / eq as determined by titration, such as at least 140 g / eq.

[0102] Aspect 4. The coating composition of any of the preceding aspects, wherein the epoxy-containing compound comprises an epoxide equivalent weight of at least 200 g / eq as determined by titration.

[0103] Aspect 5. The coating composition of any of the preceding aspects, wherein the epoxy-containing compound comprises an epoxide equivalent weight of no more than 2,000 g / eq as determined by titration, such as no more than 1,000 g / eq.

[0104] Aspect 6. The coating composition of any of the preceding aspects, wherein the epoxy-containing compound comprises an epoxide equivalent weight of no more than 750 g / eq as determined by titration.

[0105] Aspect 7. The coating composition of any of the preceding aspects, wherein the epoxy-containing compound comprises an epoxide equivalent weight of 80 g / eq to 2,000 g / eq as determined by titration, such as 140 g / eq to 1,000 g / eq.

[0106] Aspect 8. The coating composition of any of the preceding aspects, wherein the epoxy-containing compound comprises an epoxide equivalent weight of 200 g / eq to 750 g / eq as determined by titration.

[0107] Aspect 9. The coating composition of any of the preceding aspects, comprising the resin in an amount of at least 20% by weight based on total resin solids weight of the coating composition, such as at least 40% by weight.

[0108] Aspect 10. The coating composition of any of the preceding aspects, comprising the resin in an amount of no more than 95% by weight based on total resin solids weight of the coating composition, such as no more than 90% by weight.

[0109] Aspect 11. The coating composition of any of the preceding aspects, comprising the resin in an amount of 20% by weight to 95% by weight based on total resin solids weight of the coating composition, such as 40% by weight to 90% by weight.

[0110] Aspect 12. The coating composition of any of the preceding aspects, wherein the amine comprises a primary amine, a secondary amine, and / or an amide.

[0111] Aspect 13. The coating composition of any of the preceding aspects, comprising the amine in an amount of at least 3% by weight based on total resin solids weight of the coating composition, such as at least 7% by weight.

[0112] Aspect 14. The coating composition of any of the preceding aspects, comprising the amine in an amount of no more than 60% by weight based on total resin solids weight of the coating composition, such as no more than 45% by weight.

[0113] Aspect 15. The coating composition of any of the preceding aspects, comprising the amine in an amount of 3% by weight to 60% by weight based on total resin solids weight of the coating composition, such as 7% by weight to 45% by weight.

[0114] Aspect 16. The coating composition of any of the preceding aspects, wherein the styrene-maleimide copolymer comprises a reaction product of reactants comprising a styrenemaleic anhydride copolymer and / or a styrene-maleic anhydride partial ester and an amine.

[0115] Aspect 17. The coating composition of aspect 16, wherein the reactants are reacted in the presence of a non-reacting diluent at 150°C to 180°C for 2 hours to 3 hours to form an amide.

[0116] Aspect 18. The coating composition of aspect 16 or aspect 17, wherein the amine comprises a diamine, such a diamine comprising a primary amine functional group and a tertiary amine functional group.

[0117] Aspect 19. The coating composition of any of the preceding aspects, wherein the styrene-maleic anhydride copolymer comprises a butadiene- styrene maleimide copolymer and / or a styrene dimethyl aminopropylamine maleimide.

[0118] Aspect 20. The coating composition of any of the preceding aspects, wherein the styrene-maleimide copolymer comprises Structure I:, wherein y = 1 to 10; R1= Cl to CIO alkyl; R2= Cl toCIO alkyl; x = at least 1, such as at least 2, such as at least 3, such as at least 4, such as at least 5, such as at least 6; and n = 2-368, such as 2-184, such as 2-74, such as 2-37.

[0119] Aspect 21. The coating composition of any of the preceding aspects, wherein the styrene-maleimide copolymer has a weight average molecular weight of at least 1,400 g / mol as determined by gel permeation chromatography according to ASTM D6579-11, such as at least 3,000 g / mol.

[0120] Aspect 22. The coating composition of any of the preceding aspects, wherein the styrene-maleimide copolymer has a weight average molecular weight of at least 5,000 g / mol as determined by gel permeation chromatography according to ASTM D6579-11.

[0121] Aspect 23. The coating composition of any of the preceding aspects, wherein the styrene-maleimide copolymer has a weight average molecular weight of no more than 50,000 g / mol as determined by gel permeation chromatography according to ASTM D6579-11, such as no more than 20,000 g / mol.

[0122] Aspect 24. The coating composition of any of the preceding aspects, wherein the styrene-maleimide copolymer has a weight average molecular weight of no more than 10,000 g / mol as determined by gel permeation chromatography according to ASTM D6579-11.

[0123] Aspect 25. The coating composition of any of the preceding aspects, wherein the styrene-maleimide copolymer has a weight average molecular weight of 1,400 g / mol to 50,000 g / mol as determined by gel permeation chromatography according to ASTM D6579-11, such as 3,000 g / mol to 20,000 g / mol.

[0124] Aspect 26. The coating composition of any of the preceding aspects, wherein the styrene-maleimide copolymer has a weight average molecular weight of 5,000 g / mol to 10,000 g / mol as determined by gel permeation chromatography according to ASTM D6579-11.

[0125] Aspect 27. The coating composition of any of the preceding aspects, wherein the styrene-maleimide copolymer comprises a reaction product of reactants comprising a styrene monomer and a maleimide monomer.

[0126] Aspect 28. The coating composition of aspect 27, comprising the styrene monomer and the maleic anhydride monomer in a molar ratio of at least 0.1:1, such as at least 1:1.

[0127] Aspect 29. The coating composition of aspect 27 or aspect 28, comprising the styrene monomer and the maleic anhydride monomer in a molar ratio of no more than 6:1, such as no more than 3:1.

[0128] Aspect 30. The coating composition of any of aspects 27 to 29, comprising the styrene monomer and the maleic anhydride monomer in a molar ratio of 0.1:1 to 6:1, such as 1:1 to 3:1.

[0129] Aspect 31. The coating composition of any of the preceding aspects, wherein the styrene-maleimide copolymer comprises a styrene structural unit and maleimide structural unit.

[0130] Aspect 32. The coating composition of aspect 31, wherein the styrene-maleimide copolymer comprises the styrene structural unit and the maleimide structural unit in a ratio of at least 0.1:1, such as at least 1:1.

[0131] Aspect 33. The coating composition of aspect 31 or aspect 32, wherein the styrene-maleimide copolymer comprises the styrene structural unit and the maleimide structural unit in a ratio of no more than 4:1, such as no more than 3:1.

[0132] Aspect 34. The coating composition of any of aspects 31 to 33, wherein the styrene-maleimide copolymer comprises the styrene structural unit and the maleimide structural unit in a ratio of no more than 2: 1.

[0133] Aspect 35. The coating composition of any of aspects 31 to 34, wherein the styrene-maleimide copolymer comprises the styrene structural unit and the maleimide structural unit in a ratio of 0.1:1 to 4:1, such as 1:1 to 3:1.

[0134] Aspect 36. The coating composition of any of aspects 31 to 35, wherein the styrene-maleimide copolymer comprises the styrene structural unit and the maleimide structural unit in a ratio of 1 : 1 to 2: 1.

[0135] Aspect 37. The coating composition of aspect 31, wherein the styrene-maleimide copolymer comprises the styrene structural unit and the maleimide structural unit in a ratio of 0.1:1 to 1:1.

[0136] Aspect 38. The coating composition of any of the preceding aspects, comprising the styrene-maleimide copolymer in an amount of at least 2% by weight based on total resin solids weight of the composition, such as at least 4% by weight.

[0137] Aspect 39. The coating composition of any of the preceding aspects, comprising the styrene-maleimide copolymer in an amount of no more than 30% by weight based on total resin solids weight of the composition, such as no more than 20% by weight.

[0138] Aspect 40. The coating composition of any of the preceding aspects, comprising the styrene-maleimide copolymer in an amount of 2% by weight to 30% by weight based on total resin solids weight of the composition, such as 4% by weight to 20% by weight.

[0139] Aspect 41. The coating composition of any of the preceding aspects, further comprising a corrosion inhibitor, such as (a) magnesium oxide, (b) an azole such as a benzotriazole, tolyltriazole, 2,5- dimercapto-l,3,4-thiadiazole, 2-mercaptobenzothiazole, 2- mercaptobenzimidazole, l-phenyl-5- mercaptotetrazole, 2-amino-5-mercapto-l,3,4-thiadiazole, 2- mercapto-l-methylimidazole, 2- amino-5-ethyl-l,3,4-thiadiazole, 2-amino-5-ethylthio-l,3,4- thiadiazole, 5-phenyltetrazole, 7h- imidazo(4,5-d)pyrimidine, 2-amino thiazole, benzothiazole, 2- hydroxybenzothiazole, l-phenyl-4-methylimidazole, l-(p-tolyl)-4-methlyimidazole, combinations thereof, and / or salts of any of the foregoing, (c) a lithium compound such as lithium carbonate, lithium phosphate, lithium sulphate, lithium tetraborate, lithium silicate such as lithium orthosilicate (LLSiCL), lithium metasilicate, lithium zirconate, and / or lithium-exchanged silicaparticles, and / or (d) an amino acid such as histidine, arginine, lysine, cysteine, cystine, tryptophan, methionine, phenylalanine, and / or tyrosine.

[0140] Aspect 42. The coating composition of aspect 41, wherein the magnesium oxide comprises a nano-sized magnesium oxide and / or a micron-sized magnesium oxide.

[0141] Aspect 43. The coating composition of aspect 41 or aspect 42, wherein the magnesium oxide comprises ultrafine particles.

[0142] Aspect 44. The coating composition of any of aspects 41 to 43, wherein the magnesium oxide has a B.E.T. specific surface area of at least 10 nr / g as determined by nitrogen adsorption according to ASTM D3663-78.

[0143] Aspect 45. The coating composition of any of aspects 41 to 44, wherein the magnesium oxide has a B.E.T. specific surface area of 30 m2 / g to 500 m2 / g as determined by nitrogen adsorption according to ASTM D3663-78, such as 80 m2 / g to 250 m2 / g.

[0144] Aspect 46. The coating composition of any of aspects 41 to 45, wherein the magnesium oxide has a spherical morphology, a cubic morphology, a platy morphology, a polyhedric morphology, and / or an acicular morphology.

[0145] Aspect 47. The coating composition of any of the preceding aspects, wherein the composition is substantially free, or essentially free, or completely free, of a lithium compound and / or chromium (VI).

[0146] Aspect 48. The composition of any of the preceding aspects, comprising the epoxy functional groups of the epoxy-containing compound to the amine functional groups of the amine in a molar ratio of at least 1:5, such as at least 1:3.

[0147] Aspect 49. The composition of any of the preceding aspects, comprising the epoxy functional groups of the epoxy-containing compound to the amine functional groups of the amine in a molar ratio of no more than 5:1, such as no more than 3:1.

[0148] Aspect 50. The composition of any of the preceding aspects, comprising the epoxy functional groups of the epoxy-containing compound to the amine functional groups of the amine in a molar ratio of 1:5 to 5:1, such as 1:3 to 3:1.

[0149] Aspect 51 . The composition of any of the preceding aspects, wherein the coating composition is formulated as a multi-component composition, such as a 2K composition.

[0150] Aspect 52. A method for coating a substrate comprising: applying the coating composition of any of the preceding aspects to a surface of the substrate to form a coating.

[0151] Aspect 53. A substrate comprising a coating a surface thereof, formed from the coating composition of any of aspects 1 to 51.

[0152] Aspect 54. The substrate of aspect 53, comprising a metal or metal alloy, such as aluminum or steel.

[0153] Aspect 55. The substrate of aspect 54, wherein the metal alloy comprises an aluminum alloy comprising copper.

[0154] Aspect 56. The substrate of any of aspects 53 to 55, in the form of a metal sheet, coil, or aircraft part.

[0155] Aspect 57. The substrate of any of aspects 53 to 56, wherein the substrate comprises one or more intermediate layers between the substrate and the coating, such as an aluminum cladding layer, an anodized oxide layer, and / or a conversion coating.

[0156] Aspect 58. The substrate of any of aspects 53 to 57, wherein the substrate comprises an aircraft, a vehicle, a personal electronic device, a part, an article, a three- dimensional component formed by an additive manufacturing process, and / or components thereof.

[0157] Aspect 59. A use of the composition of any of aspects 1 to 51 to form a coating having improved hydraulic resistance, improved hot water resistance, and / or improved adhesive properties compared to a coating formed from a composition that does not include the styrene- maleimide copolymer.

[0158] Aspect 60. The use of aspect 59, wherein the coating has a percent weight gain of less than 33% following SKYDROL LD4 immersion for 3 days at 71°C compared to a weight of the coating prior to immersion, such as less than 20% weight gain.

[0159] Aspect 61. The use of aspect 59 or aspect 60, wherein the coating has a pencil hardness of at least H following SKYDROL LD4 immersion for 3 days at 71°C as measured by ASTM D3363-22, such as a pencil hardness of at least 2H.

[0160] Aspect 62. The use of any of aspects 59 to 61, wherein the coating has a pencil hardness of at least H following SKYDROL LD4 immersion for 28 days at 71°C as measured by ASTM D3363-22, such as a pencil hardness of at least 2H.

[0161] Aspect 63. The use of any of aspects 59 to 62, wherein the coating has a crosshatch adhesion of at least 5B following immersion in deionized water for 1 day at 71°C as measured by ASTM D3359-17, method B.

[0162] Aspect 64. The use of any of aspects 59 to 63, wherein the coating has a scratch resistance of greater than 900 grams following SKYDROL LD4 immersion for 14 days at 71 °C as measured by ISO 1518-1:2019, such as at least 1,000 grams.

[0163] Aspect 65. The use of any of aspects 59 to 64, wherein the coating has no blisters or scribe darkening and minimal salting following 2,000 hours neural salt spray testing as measured by ASTM Bl 17-19.EXAMPLES

[0164] The following examples are intended to illustrate the disclosed subject matter and should not be construed as limiting the disclosure to their details.Coating Preparations:

[0165] Epoxy / amine coating compositions were evaluated with and without styrene- maleimide copolymer for cured film properties. Resin only compositions and fully formulated pigmented compositions were tested. The fully formulated compositions recited in the examples included solvent and water-reducible two-component (2K) systems.

[0166] Coating compositions were prepared using the styrene-maleimide copolymer as shown in Table 1 in the amounts as indicated in Tables 2, 4, 7, and 9.Table 1 : Raw Materials and SuppliersSubstrates And Coating Applications:

[0167] Coatings were applied on abraded bare 2024-T3 grade aluminum panels, available from Priority Metals, Inc., unless otherwise specified.

[0168] Abraded bare aluminum panels were machine- scrubbed with an abrasive pad, SCOTCHBRITE 7447 PRO, wiped with methyl ethyl ketone (MEK) solvent, and dried under ambient condition.

[0169] Pretreatments included PREKOTE, available from Pantheon Chemicals, applied per manufacturer’s specifications to 2024-T3 panels and Alodine 1200S pretreated aluminum panels available from K&L.

[0170] Unless otherwise specified, CONTROL and EXAMPLE coating compositions were applied using HVLP spray equipment (Vendor: Anest Iwata, Model: LPH300LV) with a tip size of 1.2 mm and a pressure setting of 30 psi, within 60 minutes of combining base and activator. CONTROL and EXAMPLE coatings were applied to a dry film build of approximately 25 microns.

[0171] In some examples, the CONTROL and EXAMPLE coatings were evaluated as primers, and a polyurethane topcoat, CA9311, commercially available from PPG, was spray applied to each primer within 2 to 5 hours of the primer application. The topcoat dry film build was approximately 60 microns.

[0172] Unless otherwise stated, the applied coatings were cured at ambient conditions for 14 days prior to testing.Test Methods:

[0173] Unless otherwise stated, coated films were evaluated using the following test methods.

[0174] Crosshatch Adhesion Testing: Crosshatch adhesion was determined according to ASTM D3359-17 (Standard Test Methods for Measuring Adhesion by Tape Test), method B. Dry adhesion was tested after fully curing the coating system for 14 days.

[0175] Pencil Hardness: Pencil hardness was determined in accordance with ASTM D3363-22 (Standard Test Method for Film Hardness by Pencil Test).

[0176] Methyl Ethyl Ketone (MEK) Double Rubs: MEK double rub solvent resistance was determined according to ASTM D5402-19.

[0177] GE Impact Resistance: Coatings were applied on abraded bare 2024-T0 grade aluminum panels. GE Impact by visual inspection was determined according to ASTM D2794- 93. GE Impact by pinhole detection was determined according to ASTM G62-23.

[0178] Hot Water Resistance: The cured coated panels were fully immersed in deionized water for 1 day at 160°F (71°C). Excess water was removed by gauze and the panels were dried at ambient conditions for 1 hour prior to crosshatch adhesion testing according to the test method described above.

[0179] Dry-To-Tapc: After coating application, a strip of masking tape (3M #250) was applied to the coated surface and pressed down with a roller having a weight of approximately 2 kilograms. Tape strips were applied starting one hour after coating application and after eachadditional hour to a maximum of 6 hours. The panel was allowed to dry overnight in ambient conditions. The tape strips were then removed by a steady, moderate motion pulling at the free end. The tapes were pulled starting with the tape applied soonest after coating application, and then for tapes applied after successive hours, until the tape was removed without visible change to the coating surface. The dry-to-tape time was reported as less than the hours corresponding to how many hours after coating application this tape had been applied.

[0180] Scratch resistance: Scratch resistance was evaluated using ISO1518-l:2019.

[0181] Low temperature flexibility: Low temperature flexibility was evaluated using ASTM D522 / D522M-17.

[0182] Humidity resistance: Humidity resistance was evaluated using ASTM D2247-15.

[0183] Neutral salt spray corrosion resistance: Neutral salt spray corrosion resistance (NSS) was evaluated using ASTM Bl 17-19.

[0184] Fluid resistance: Unless otherwise stated, the cured panels were fully immersed in the test fluids, MOBIL jet oil MIL-PRF-23699, hydraulic fluid MIL-PRF-83282, or hydraulic fluid SKYDROL LD4, at the temperature and for the duration as described with each set of samples. Unless otherwise stated, excess fluid was removed by gauze at the end of the treatment and the panels were rinsed with water and dried at ambient conditions for an hour before testing was performed using the testing methods as described above.Coating Compositions and Coating PerformanceSet 1: Resin Only Coating Compositions CONTROL 1 and EXAMPLE 1

[0185] Non-pigmented, two-component (2K), epoxy-amine coating compositions, CONTROL 1 , and EXAMPLE 1 , were prepared using the materials and weights as shown in Table 2. Materials were added in sequence and the mixture was mixed until homogeneous using a FlackTek Speedmixer, available from FlackTek.Table 2: Coating Compositions for CONTROL 1 and EXAMPLE 1

[0186] CONTROL 1 AND EXAMPLE 1 were applied on bare 2024-T3 using a 3-mil (76 micron) gap drawdown bar’ and cured overnight at 49°C before testing. Test results are shown in Table 3.

[0187] Additionally, CONTROL 1 and EXAMPLE 1 were applied onto polytetrafluoroethylene plastic caps having a diameter of 6 centimeters, to approximately 1.6 grams per dried sample, and allowed to dry for 7 days at ambient. Then, each film was removed from the plastic, weighed, and immersed in SKYDROL LD4 for 3 days at 71 °C. Immersed films were removed from the SKYDROL, rinsed with acetone, and allowed to dry at ambient conditions, and then reweighed. Percent weight gain of each film was determined, as recorded in Table 3.Table 3: Coated Panel and Film Performance for CONTROL 1 AND EXAMPLE 1

[0188] As shown in Table 3, EXAMPLE 1, the composition including a styrene- maleimide copolymer, had significantly improved resistance to SKYDROL LD4 (as shown by less weight gain after immersion) as compared with CONTROL 1, without the styrene-maleimide copolymer. EXAMPLE 1 also demonstrated improved pencil hardness and hot water resistance, while maintaining impact resistance (GE impact) as an indicator of flexibility.Set 2: Pigmented (Primer) Compositions CONTROL 2 and EXAMPLES 2-3

[0189] Fully formulated solvent- borne epoxy-amine coating compositions, CONTROL2, and EXAMPLES 2-3, were prepared using the materials and weights as shown in Table 4. For the pigmented bases, the epoxy resin, additives and fillers, and corrosion inhibitors and pigments, were combined and premixed with solvent. The premixture was then milled with grinding media using an Eiger bead milling machine until a 6+ Hegman grind was achieved. The milled base was then discharged, filtered, and let down with additional solvent, if necessary. For the activators, the materials were added, in sequence, to the solvent and mixed until homogeneous.Table 4: Coating compositions for CONTROL 2 and EXAMPLES 2-3

[0190] Compositions, CONTROL 2, and EXAMPLES 2-3, were applied over PREKOTE pretreated 2024-T3 and bare abraded 2024-T0 aluminum panels. Dry-to-tape time was evaluated on freshly coated panels. SKYDROL LD4 immersion testing was evaluated on coated panels cured for 1 day at ambient, followed by 1 day at 49°C. All other testing was evaluated on coated panels after cure for 14 days at ambient temperature. Results are shown in Table 5. Results including a topcoat are shown in Table 6.Table 5: Coated Panel Performance for Primers Only CONTROL 2 and EXAMPLES 2-3Table 6: Coated Panel Performance for Primers CONTROL 2 and EXAMPLES 2-3 Primers with CA9311 Polyurethane Topcoat

[0191] As shown in Tables 5 and 6, coated panels prepared using compositions with epoxy, amine and a styrene-maleimide copolymer, EXAMPLES 2-3, had significantly improved resistance to SKYDROL LD4 as tested both as primer only, and as primer with topcoat, as compared with CONTROL 2. Also, as shown in Table 5, flexibility was maintained with the addition of a higher (doubled) level of styrene-maleimide copolymer as indicated by the impact test results of Examples 2 and 3.Set 3: Pigmented (Primer) Compositions CONTROL 4 and EXAMPLES 6-7

[0192] Epoxy-amine coating compositions CONTROL 4 and EXAMPLES 6-7 were prepared using the materials and weights as shown in Table 6. For the pigmented bases, the epoxy resin, additives and fillers, and corrosion inhibitors and pigments, were combined and premixed with solvent. The premixture was then milled with grinding media using an Eiger bead milling machine until a 6+ Hegman grind was achieved. The milled base was then discharged, filtered, and let down with additional solvent if necessary. For the activators, the materials were added, in sequence, to the solvent and mixed until homogeneous. The thinner was prepared by mixing the components until homogeneous.Table 7: Coating compositions for CONTROL 3 and EXAMPLES 4-5

[0193] Coatings were applied over PREKOTE pretreated 2024-T3 aluminum panels and cured for 14 days at ambient temperature for subsequent testing. Test results are provided in Table 8.Table 8: Coated Panel Performance for CONTROL 3 and EXAMPLES 4-5

[0194] As shown in Table 8, coatings comprising an epoxy resin, an amine, and a styrene-maleimide copolymer (EXAMPLES 4 and 5) had improved SKYDROL LD4 resistance compared to CONTROL 3 without the styrene-maleimide copolymer, as demonstrated by crosshatch adhesion and pencil hardness after immersion.Set 4: Water- Reducible Compositions and Coated Film Performance

[0195] Water-reducible compositions were prepared using 44GN098 / 44GN098 epoxy / amine 2K coatings commercially available from PPG. CONTROL 4 was prepared and mixed according to the manufacturer’s instruction. EXAMPLE 6 was prepared by adding SMA3000I (25% solution in nitroethane) to the mixed base and activator before water reduction. Coating compositions were applied within 30 to 60 minutes after mixing all materials.Table 9: Coating Compositions for CONTROL 4 and EXAMPLE 6

[0196] Coatings were applied over Alodine 1200S pretreated 2024-T3 aluminum panels and cured for 14 days at ambient temperature for subsequent testing. Test results are provided in Table 10.Table 10: Coated Panel Performance for CONTROL 5 and EXAMPLE 6

[0197] As shown in Table 10, EXAMPLE 6, a water reducible coating composition comprising epoxy resin, amine, and a styrene-maleimide copolymer, had improved SKYDROL LD4 resistance compared to CONTROL 4, while also maintaining corrosion performance.

[0198] It will be appreciated by skilled artisans that numerous modifications and variations are possible in light of the above disclosure without departing from the broad inventive concepts described and exemplified herein. Accordingly, it is therefore to be understood that the foregoing disclosure is merely illustrative of various exemplary aspects ofthis application and that numerous modifications and variations can be readily made by skilled artisans which arc within the spirit and scope of this application and the accompanying claims.

Claims

We claim:

1. A coating composition comprising:(a) a resin comprising an epoxy-containing compound;(b) an amine; and(c) a styrene-maleimide copolymer, wherein the coating composition comprises a liquid.

2. The coating composition of claim 1, wherein the epoxy-containing compound comprises a monoepoxide and / or a poly epoxide.

3. The coating composition of any of the preceding claims, wherein the epoxy-containing compound comprises an epoxide functional group and a functional group in addition to the epoxide functional group.

4. The coating composition of claim 3, wherein the functional group in addition to the epoxide functional group comprises a hydroxide functional group, a silane functional group, a sulfide functional group, and / or a (meth)acrylate functional group.

5. The coating composition of any of the preceding claims, wherein the amine comprises a primary amine, a secondary amine, and / or an aminosilane.

6. The coating composition of any of the preceding claims, wherein the styrene-maleimide copolymer comprises a weight average molecular' weight of 1,400 g / mol to 50,000 g / mol, as measured by gel permeation chromatography according to ASTM D6579-11.

7. The coating composition of any of the preceding claims, wherein the styrene-maleimide copolymer comprises a ratio of styrene structural units to maleimide structural units of 0.1:1 to8. The coating composition of any of the preceding claims, wherein the styrene-maleimide copolymer comprises a tertiary amine.

9. The coating composition of any of the preceding claims, comprising: i) the resin in an amount of 20% by weight to 95 % by weight based on total resin solids weight of the coating composition; ii) the amine in an amount of 3% by weight to 60% by weight based on total resin solids weight of the coating composition; and / or iii) the styrene-maleimide copolymer in an amount of 2% by weight to 30% by weight based on total resin solids weight of the coating composition.

10. The coating composition of any of the preceding claims, wherein the coating composition is formulated as a multi-component coating composition.

11. The coating composition of any of the preceding claims, wherein the coating composition is substantially free of a chromium (VI) -containing material.

12. A method for coating a substrate comprising: applying the coating composition of any of the preceding claims to a surface of the substrate.

13. A substrate comprising a coating formed from the coating composition of any of claims 1 to 11 on a surface of the substrate.

14. The substrate of claim 13, comprising a metal or metal alloy, such as aluminum or steel, optionally in the form of a metal sheet, coil, three-dimensional shaped part, or an aircraft part.

15. The substrate of claim 14, wherein the metal alloy comprises an aluminum alloy comprising copper.

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