Dual cure epoxy coatings and methods of making the same

Abstract

A method of coating an article includes preparing a coating composition with an epoxy component; an amine component; and a catalyst; the epoxy component and the amine component being present in the coating composition at the ratio of 0.8:1 to 1.5:1; applying the coating composition onto the article; and within 60 minutes of the applying, curing the coating composition at a temperature of 135 degrees C to 250 degrees C to form a cured coating having a gloss rating of 60 Gloss Units (GU) or higher. Coating compositions and coated articles are also provided.

Description

[0001] DUAL CURE EPOXY COATINGS AND METHODS OF MAKING THE SAME

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of U.S. Provisional Application No. 63 / 532,215, filed 11 August 2023, the disclosure of which is incorporated by reference herein in its entirety.

[0004] FIELD

[0005] The present disclosure relates to epoxy coatings. The present disclosure further relates to epoxy coatings prepared using a dual cure method.

[0006] BACKGROUND

[0007] Protective coatings have found wide applications in protecting surfaces from abrasion, corrosion, and chemical, mechanical, and physical damage. Coatings perform an integral role in diverse industries, including petroleum, oil, gas, and chemical transportation. Epoxy coatings have found progressively greater use due to their excellent corrosion resistance and acid and alkali resistance aided by their superior mechanical properties.

[0008] Traditionally, two-component epoxy -amine cured coatings utilize higher molecular- weight epoxy resins with hardeners / catalysts and cure under specific conditions to achieve desirable properties. Higher molecular-weight epoxies perform better than lower molecular- weight epoxies, but the use of higher molecular-weight epoxies necessitates employing more volatile organic compounds (VOCs) in the formulation. The curing process releases VOCs into the atmosphere during the curing or baking cycles or air drying. Reducing VOC content in epoxy coatings is challenging and may result in unevenly coated substrates and blistering. It would be desirable to provide coatings that provide superior performance. Furthermore, it would be beneficial to provide coatings that provide superior performance while mitigating the release of high VOC content. It would be desirable to provide coatings that have low VOC content without blistering or uneven coating or substrates.

[0009] Further improvements to methods of preparing coating compositions comprising epoxy and amine components and applying those coating compositions to the surfaces of substrates as coatings, such that side reactions affecting the product quality could be avoided, are desired. Furthermore, methods to circumvent the release of VOCs in the atmosphere while providing epoxy-amine coatings with higher molecular weight epoxies in the epoxy-amine coating systems are highly desired.

[0010] SUMMARY

[0011] The present disclosure broadly relates to methods of preparing coating compositions comprising epoxy components, amine components, and optionally catalysts and other additives, and applying those coating compositions to the surfaces of substrates as coatings. The present disclosure further relates to coatings and coated articles coated with the coating compositions.

[0012] In some embodiments, the methods of coating articles include preparing a coating system. In some embodiments, a coating system includes an epoxy component, an amine component, and a catalyst. The epoxy component and the amine component may be present in the coating composition at the ratio of 0.8 : 1 to 1.5 : 1. In some embodiments, the stoichiometric ratio of the epoxy component to the amine component may be from 1 : 1 to 5: 1.

[0013] In some embodiments, the epoxy component may have a molecular weight range of 175 to 1200. In some preferred embodiments, the epoxy component may have a molecular weight range of 200 to 350. In some embodiments, the epoxy component may have 1 to 5 epoxide groups. In some embodiments, the epoxy component may include at least two different epoxy resins. In some embodiments, the amine component may include at least two different amine components. In some embodiments, the catalyst may include at least two different catalysts. In some embodiments, the coating composition may be free or substantially free of additional solvents. In some embodiments, the coating composition may include less than 1 wt-% organic solvents by weight of the coating composition. In some embodiments, the coating composition may include 100 wt-% solids by weight of the coating composition.

[0014] In some embodiments, the methods of coating include applying the coating composition to an article and curing the coating composition to form a cured coating. In preferred embodiments, the coating composition may be cured within 60 minutes of applying it to a substrate. In some preferred embodiments, the coating composition applied to a substrate may be cured at a temperature of 135 degrees C to 250 degrees C to form a cured coating.

[0015] The prepared cured coatings may include epoxy homopolymer segments. In some embodiments, cured coatings may include epoxy homopolymer segments with repeating units separated by ether linkages. In some preferred embodiments, the cured coating may include epoxy homopolymer segments comprising 2 or more repeating units separated by ether linkages.

[0016] The coating composition may be applied to any article that may benefit from being coated with the cured coating. The cured coatings of present disclosure may display superior characteristics and properties such as higher gloss and stronger solvent resistance. In some embodiments, the cured coating may exhibit a rub test result of 50 double rubs or higher. In preferred embodiments, the cured coating may have a gloss rating of 60 Gloss Units (GU) or higher. In some embodiments, the coating compositions of the present disclosure are useful to coat pipes, chemical tanks (holding and process tanks), pipelines, connectors, etc., as substrates. In a preferred embodiment, the substrate is made of steel.

[0017] DEFINITIONS

[0018] All scientific and technical terms used herein have meanings commonly used in the art unless otherwise specified. The definitions provided herein are to facilitate understanding of certain terms used frequently herein and are not meant to limit the scope of the present disclosure.

[0019] Unless otherwise indicated, the terms “polymer” and “polymeric material” include, but are not limited to, organic homopolymers, copolymers, such as for example, block, graft, random and alternating copolymers, terpolymers, etc., and blends and modifications thereof. Furthermore, unless otherwise specifically limited, the term “polymer” shall include all possible geometrical configurations of the material. These configurations include, but are not limited to, isotactic, syndiotactic, and atactic symmetries.

[0020] The term “aliphatic group” means a saturated or unsaturated linear or branched hydrocarbon group. This term is used to encompass alkyl, alkenyl, and alkynyl groups, for example.

[0021] The term “alkyl” is used in this disclosure to describe a monovalent group that is a radical of an alkane and includes straight-chain, branched, cyclic, and bicyclic alkyl groups, and combinations thereof, including both unsubstituted and substituted alkyl groups. Unless otherwise indicated, the alkyl groups typically contain from 1 to 30 carbon atoms. In some embodiments, the alkyl groups contain 1 to 20 carbon atoms, 1 to 10 carbon atoms, 1 to 6 carbon atoms, 1 to 4 carbon atoms, or 1 to 3 carbon atoms. Examples of alkyl groups include methyl, ethyl, n-propyl, n-butyl, n-pentyl, isobutyl, t-butyl, isopropyl, n-octyl, n-heptyl, ethylhexyl, cyclopentyl, cyclohexyl, cycloheptyl, etc.

[0022] The term “alkylated” is used in this disclosure to describe compounds that are reacted to replace a hydrogen atom or a negative charge of the compound with an alkyl group, such that the alkyl group is covalently bonded to the compound.

[0023] The term “aromatic ring” is used in this disclosure to refer to a conjugated ring system of an organic compound. Aromatic rings may include carbon atoms only, or may include one or more heteroatoms, such as oxygen, nitrogen, or sulfur.

[0024] Substitution on the organic groups of the compounds of the present disclosure is possible. When the term “group” is used herein to describe a chemical substituent, the described chemical material may include the unsubstituted group and / or that group with 0, N, Si, or S atoms, for example, in the chain (as in an alkoxy group) as well as carbonyl groups or other conventional substitutions. For example, the phrase “alkyl group” is intended to include not only pure open chain saturated hydrocarbon alkyl substituents, such as methyl, ethyl, propyl, t-butyl, and the like, but also alkyl substituents bearing further substituents known in the art, such as hydroxy, alkoxy, alkylsulfonyl, halogen atoms, cyano, nitro, amino, carboxyl, etc. Thus, “alkyl group” includes ether groups, haloalkyls, nitroalkyls, carb oxy alky Is, hydroxyalkyls, sulfoalkyls, etc.

[0025] The term “crosslinker” refers to a molecule capable of forming a covalent linkage between polymers or between two different regions of the same polymer. The term “crosslinker,” as used herein, is interchangeable with “hardener.” The term “curing agent” refers to a component that includes both (or can be used) as both “crosslinkers” or “hardener” and “catalyst” or “catalyst package.

[0026] Unless otherwise indicated, a reference to a “(meth)acrylate” compound (where “meth” is bracketed) is meant to include both acrylate and methacrylate compounds.

[0027] Unless otherwise indicated, all parts, ratios, and percentages are by weight and all molecular weights are number average molecular weight (Mn). Molecular weight may be determined by various techniques well known in the art. With respect to the components and / or compositions described herein, molecular weight is preferably determined by gel permeation chromatography (GPC).

[0028] The term “substantially” as used here has the same meaning as “significantly,” and can be understood to modify the term that follows by at least about 90 %, at least about 95 %, or at least about 98 %. The term “substantially free” of a particular compound means that the compositions of the present invention contain less than 1,000 parts per million (ppm) of the recited compound. The term “essentially free” of a particular compound means that the compositions of the present invention contain less than 100 parts per million (ppm) of the recited compound. The term “completely free” of a particular compound means that the compositions of the present invention contain less than 20 parts per billion (ppb) of the recited compound. In the context of the aforementioned phrases, the compositions of the present invention contain less than the aforementioned amount of the compound whether the compound itself is present in unreacted form or has been reacted with one or more other materials.

[0029] The term “not substantially” as used here has the same meaning as “not significantly,” and can be understood to have the inverse meaning of “substantially,” i.e., modifying the term that follows by not more than 25 %, not more than 10 %, not more than 5 %, or not more than 2 %.

[0030] The term “about” is used here in conjunction with numeric values to include normal variations in measurements as expected by persons skilled in the art, and is understood to have the same meaning as “approximately” and to cover a typical margin of error, such as ±5 % of the stated value.

[0031] Terms such as “a,” “an,” and “the” are not intended to refer to only a singular entity, but include the general class of which a specific example may be used for illustration.

[0032] The terms “a,” “an,” and “the” are used interchangeably with the term “at least one.” The phrases “at least one of’ and “comprises at least one of’ followed by a list refers to any one of the items in the list and any combination of two or more items in the list.

[0033] As used here, the term “or” is generally employed in its usual sense including “and / or” unless the content clearly dictates otherwise. The term “and / or” means one or all of the listed elements or a combination of any two or more of the listed elements. The recitations of numerical ranges by endpoints include all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc. or 10 or less includes 10, 9.4, 7.6, 5, 4.3, 2.9, 1.62, 0.3, etc.). Where a range of values is “up to” or “at least” a particular value, that value is included within the range.

[0034] As used here, “have,” “having,” “include,” “including,” “comprise,” “comprising,” or the like are used in their open-ended sense, and generally mean “including, but not limited to.” It will be understood that “consisting essentially of,” “consisting of,” and the like are subsumed in “comprising” and the like. As used herein, “consisting essentially of,” as it relates to a composition, product, method, or the like, means that the components of the composition, product, method, or the like are limited to the enumerated components and any other components that do not materially affect the basic and novel characteristic(s) of the composition, product, method, or the like.

[0035] The words “preferred” and “preferably” refer to embodiments that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the disclosure, including the claims.

[0036] Any direction referred to here, such as “top,” “bottom,” “left,” “right,” “upper,” “lower,” and other directions and orientations are described herein for clarity in reference to the figures and are not to be limiting of an actual device or system or use of the device or system. Devices or systems as described herein may be used in a number of directions and orientations.

[0037] The term “on”, when used in the context of a coating applied on a surface or substrate, includes both coatings applied directly or indirectly to the surface or substrate. Thus, for example, a coating applied to a primer layer overlying a substrate constitutes a coating applied on the substrate.

[0038] DETAILED DESCRIPTION

[0039] The present disclosure broadly relates to methods of preparing coating compositions comprising epoxy components, amine components, and optionally catalysts and other additives, and applying those coating compositions to the surfaces of substrates as coatings. The present disclosure further relates to coatings and coated articles coated with the coating compositions.

[0040] The coating compositions of the present disclosure may be used for many purposes. The coating compositions of the present disclosure may be used to coat various surfaces. The coating compositions of the present disclosure may be used to coat surfaces of articles. Such articles may be made of various materials. The present disclosure provides methods for preparing coating compositions, coating articles with the coating composition, methods for preparing coatings, and articles coated with the coating composition. In some embodiments, the coating composition may be used to coat articles that come into contact with chemicals during chemical processing or manufacturing, such as pipes, chemical tanks (holding and process tanks), pipelines, connectors, and the like.

[0041] Epoxy coatings are usually formulated as two-component systems with an epoxy component and an amine component, as the two main components. The amine component reacts with the epoxy component to open the oxirane rings (epoxy-amine cure), followed by a chainextension polymerization reaction (polymerization cure).

[0042] According to an embodiment, the coating compositions of the present disclosure are based on three or more reactive compounds: an epoxy component, an amine component, and a catalyst. The coating is applied to an article and is cured at an elevated temperature within 60 minutes of applying the coating. In other words, the coating is cured at an elevated temperature without a long delay that is typically used in the industry to allow solvents to evaporate and / or to allow for an epoxy-amine cure to occur. According to an embodiment, the coating composition is cured at a temperature of 70 °C to 250 °C. The cured coating may exhibit a gloss rating of 60 Gloss Units (GU) or higher. The cured coating may include epoxy homopolymer segments that are longer than corresponding epoxy segments in coatings of the prior art. The cured coating may include epoxy homopolymer segments comprising 2 or more repeating units separated by ether linkages.

[0043] In typical epoxy-amine coatings, an epoxy resin component is mixed with the amine component, and the mixture is applied to an article with a surface to be coated. The reaction (also known as epoxy-amine cure) allows the epoxy component and the amine component to react in an SN2 manner to furnish epoxide-ring-opening reaction products. Typically, the epoxy-amine cure proceeds at room temperature, and it takes several hours before the reaction is allowed to proceed to the polymerization step (also known as polymerization cure). After the epoxy-amine cure, the article with the coated surface may be baked at elevated temperatures for the polymerization of the epoxy-amine coating composition. This epoxy-condensation reaction (polymerization or chain extension) furnishes the polymer product. Typically, high molecular weight epoxy components are used as starting materials to achieve superior performance from the product. However, it is commonly understood in the industry that the use of high molecular weight epoxy components necessitates the use of solvents and thus additional VOCs. Further, solvent-based epoxy-amine coatings currently used as internal pipe coatings in the petrochemical industry are typically prepared by first coating the article, storing the coated article at ambient temperature for several hours (for example, overnight or from 6 to 24 hours), and then curing the coating in a 2 'Z-hour bake at 110 °C (230 °F). The long storage time allows a majority of the solvent to evaporate before oven curing.

[0044] According to embodiments of the present disclosure, the epoxy component is mixed with an amine component and a catalyst, and the mixture is applied to an article with a surface to be coated. The coated article is then cured at an elevated temperature within a predetermined amount of time, for example, within 60 minutes of applying the coating. This allows both the epoxy-amine cure and the polymerization cure to proceed simultaneously, providing a “dualcure” to the coating. The coating compositions of the present disclosure reduce the reaction times compared to conventional coatings. The coating compositions of the present disclosure may help streamline the coating process due to the absence of a long wait time between application and curing. Additionally, the coating compositions of the present disclosure reduce or minimize amine-blush. Furthermore, the coating compositions of the present disclosure provide high- quality coatings from low molecular weight epoxy component starting materials. In exemplary embodiments, the coating compositions of the present disclosure provide coatings with superior performance characteristics while mitigating the use of VOCs.

[0045] COATING COMPOSITIONS

[0046] According to an embodiment, the coating compositions of the present disclosure include an epoxy component, an amine component, and a catalyst. The coating compositions may be cured to form a cured coating. The coating compositions may further include optional additives. Each of the components is discussed in further detail below.

[0047] According to an embodiment, at least some of the components (the epoxy component, the amine component, the catalyst, and optional additives) are liquids. Preferably, the components, when mixed together, have a viscosity that is such that the coating composition does not require the use of any solvents. To the extent that some of the epoxy component, the amine component, the catalyst, and optional additives would be considered solvents, the coating composition may be prepared without any additional solvents. The term “additional solvent” is used here to refer to any solvent that is added to a composition for the purpose of solvating or diluting and is not present in the composition for its role as an epoxy component, amine component, catalyst, or additive providing an additive function as described below. In some embodiments, the coating composition includes 10 wt-% or less, 7 wt-% or less, 5 wt-% or less, 4 wt-% or less, 3 wt-% or less, 2 wt-% or less, or 1 wt-% or less of additional solvents. In some embodiments, the coating composition is free or substantially free of additional solvents.

[0048] In some embodiments, the coating composition includes a single type of epoxy component.

[0049] The epoxy component and the amine component may be present in the coating composition at a ratio that provides at least 0.8 parts of epoxy component to every 1 part of amine component. In some embodiments, the coating composition includes at least an equivalent amount or an excess of epoxy relative to amine. An excess of epoxy component may further promote homopolymerization of the epoxy component during curing. The epoxy component and amine component may be present in the coating composition at a ratio of 1 or more parts of epoxy component for every 1 part of amine component, 1.2 or more parts of epoxy component for every 1 part of amine component, 1.5 or more parts of epoxy component for every 1 part of amine component, 1.8 or more parts of epoxy component for every 1 part of amine component, or 2 or more parts of epoxy component for every 1 part of amine component.

[0050] The epoxy component, the amine component, the catalyst, and optional additives further discussed in detail below. EPOXY COMPONENTS

[0051] As used in the present disclosure, “epoxy component” and “epoxy components” include resins or compounds containing epoxide groups, also known as oxirane groups or ethoxyline groups. These epoxy components include a wide variety of curable epoxy compounds and combinations thereof. Useful epoxy components include liquids, solids, and mixtures thereof. In some embodiments, the coating composition includes a single type of epoxy component. In some embodiments, the coating composition includes more than one type of epoxy component. In some embodiments, in which the coating composition includes more than one type of epoxy component, one of the epoxy components is a primary epoxy component, making up 80 wt-% or more, 85 wt-% or more, 90 wt-% or more, 95 wt-% or more, or 98 wt-% or more of the total epoxy components.

[0052] The epoxy components in the coating compositions of the present disclosure may include, for example, diglycidyl ether of bisphenol A (DGBA), diglycidyl ether of bisphenol F (DGBF), diglycidyl ether of tetrabromobisphenol A (DGBTA), novolac-based epoxy resins, trisepoxy resins, higher molecular weight resins (including, for example, diglycidyl ether of bisphenol A advanced with bisphenol A, and the like), or polymerized unsaturated monoepoxides (including, for example, glycidyl acrylates, glycidyl methacrylate, allyl glycidyl ether, and the like).

[0053] In some embodiments, the epoxy components of the present disclosure may include 1 to 5 epoxide groups per molecule. Epoxy components of the present disclosure include epoxy resins based upon bisphenol A. For example, preferred epoxy resins in the coating compositions of the present disclosure are diglycidyl ether of bisphenol A ( DGBA) resins of the following structure:

[0054] Where, generally, n = 0.15 or greater.

[0055] DGBA resins are available, for example, as EPON™ 828RS (available from Westlake

[0056] Epoxy, in Columbus, OH) or EPON™ 828LS (available from Westlake Epoxy.), or D.E.R ™ 331 (available from Dow Inc. in Midland, MI). Suitable epoxy components of the coating composition include epoxy and modified epoxy resins selected from bisphenol A, bisphenol F, novolac epoxies, non-aromatic epoxies, cycloaliphatic epoxies, glycidyl esters, epoxy functional acrylics, and any combinations thereof. In some embodiments, the epoxy component of the present disclosure may include two different epoxy resins. Some suitable commercially available epoxy resins (in addition to the ones mentioned above) include, for example, EPIKOTE™ 828 (available from Westlake Epoxy in Houston, TX), ARALDITE® GY 250 (available from Huntsman Corp, in The Woodlands, TX), EPIKOTE™ 1004 (available from Westlake Epoxy), D.E.R ™ 664-20 (available from Dow Chemicals Corp.), EPIKOTE™ 1001-X-75 (available from Westlake Epoxy), ARALDITE® GZ 7071-X-75BD (available from Huntsman Corp.), D.E.R.™ 352 (available from Dow Chemicals Corp.), EPIKOTE™ 232 (available from Westlake Epoxy), EPIKOTE™ 862 (available from Westlake Epoxy), D.E.N ™ 438-X-80 (available from Palmer Holland in Westlake, OH), and EPIKOTE™ 154 (available from Westlake Epoxy), and mixtures and combinations thereof. In some embodiments, the epoxy component includes or is DGBA, such as those available as EPON™ 828RS (available from Westlake Epoxy), EPON™ 828LS (available from Westlake Epoxy), and D.E.R.™ 331 (available from Dow Chemicals Corp.).

[0057] The epoxy components may be described, in part by their Epoxide Equivalent Weight (“EEW”). Knowing the EEW of a particular epoxy component is often helpful when determining the amount of other ingredients to be added to the composition to prepare a coating composition of the present disclosure. Some resins, for example, D.E.R ™ 331, may have epoxy equivalent weights in the range of about 180-195 g / mol. Others, such as D.E.R.™ 332, may have epoxy equivalent weights in the range of about 170-175 g / mol. Some commercially available epoxy component materials available under trade designations such as EPON™ 828, EPON™ 1001, EPON™ 1007, and EPON™ 1009 (available from Westlake Epoxy) may have varying EEWs that may be adjusted prior to use. The adjustment of the epoxy component material to obtain the desired EEW may be accomplished by the addition of a dihydroxy compound, for example, bisphenol A. The amount of bisphenol A useful to adjust the EEW in the epoxy components of the present disclosure depends on the desired EEW. Commercially available epoxy component materials may contain a mixture of diepoxides, monoepoxides, and aromatic polyethers. In some embodiments, the epoxy component has a molecular weight range of 175 to 1200 Daltons. In some embodiments, the epoxy component has a molecular weight range of 200 to 350 Daltons.

[0058] AMINE COMPONENTS

[0059] The coating compositions of the present disclosure include an amine component. The amine component may be a polyamine. The term “polyamine,” as utilized herein, may also be referred to as multifunctional amine, and describes compounds with amine functionality and contains at least two active amine hydrogens. These amine components have, on average, more than one active hydrogen atom, wherein the active hydrogen atoms may be bonded to the same nitrogen atom or to different nitrogen atoms. Such amine components may include those compounds that contain a primary amine moiety, and compounds that contain two or more primary or secondary amine or amide moieties linked to a common central organic moiety.

[0060] The polyamines or multifunctional amines that are within the scope of the present disclosure include, for example, aliphatic polyamines, polyether amines, cycloaliphatic amines, aromatic amines, heterocyclic amines, arylaliphatic amines, amidoamines, and polyamides. The polyamines also include Mannich base derivatives of aliphatic amines, cycloaliphatic amines, aromatic amines, polyamides or amidoamines, and amine-epoxy adduct derivatives of aliphatic amines, cycloaliphatic amines, aromatic amines, polyamides, or amidoamines with monoglycidyl ethers of glycols or phenols, glycidyl ethers of bisphenol A or bisphenol F or epoxy novolac resins, and the like, and mixtures and combinations thereof.

[0061] Some examples of aliphatic polyamines as amine components of the coating composition include polyethyleneamines (including, for example, ethylenediamine, diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), and the like), polypropyleneamines (including, for example, dipropylenetriamine, tripropylenetetramine, and the like), aminopropylated ethylenediamines (including, for example, N-3 -aminopropyl ethylenediamine, N,N'-bis(3 -aminopropyl) ethylenediamine, N,N,N'-tris(3- aminopropyl) ethylenediamine, and the like), aminopropylated propylenediamines, 1,6- hexanediamine (HMDA), 2,4,4-trimethyl-l,6-hexanediamine, N-3 -aminopropyl- 1,3- diaminopropane, N,N'-bis(3-aminopropyl)-l,3-diaminopropane, N,N,N'-tris(3 -aminopropyl)-!, 3- diaminopropane, 2-methyl-l,5-pentanediamine, and mixtures and combinations thereof. Some examples of polyether amines as amine components of the coating composition include poly(alkylene oxide) monoamines, diamines, and triamines. In some embodiments, polyether amines include, for example, polyethylene oxide), polypropylene oxide), and poly(tetramethylene oxide) monoamines, diamines, and triamine. In some embodiments, polypropylene oxide) monoamines, diamines, and triamines useful in the present disclosure are commercially available under the .JEFF AMINE® trademark. Illustrative examples include polypthylene glycol-block-propylene glycol)(2-amino-2-methyl)methyl ether (available as JEFF AMINE® M-600, JEFF AMINE® M-1000, JEFF AMINE® M-2005, and JEFF AMINE® M- 2070 from Huntsman Corp.), polypthylene glycol-block-propyleneglycol)bis(2-amino-2-methyl) ether (available as JEFF AMINE® ED600, JEFF AMINE® ED900, and JEFF AMINE® ED 2001 from Huntsman Corp.), tri(2-amino-2-methylethyl) trimethylolpropane ether (available as JEFF AMINE® T-403 from Huntsman Corp.), tri(2-aminopoly(propylene oxide) glycerine ether (available as JEFF AMINE® T-5000 from Huntsman Corp.), bi s(3 -aminopropyl) polypropylene glycol ether (available as JEFF AMINE® D230, JEFF AMINE® D400, JEFF AMINE® D2000, and JEFF AMINE® D4000 from Huntsman Corp.), and mixtures and combinations thereof. Polypthylene oxide) monoamines, diamines, and triamines include, for example, triethylene glycol diamine (available as JEFF AMINE® XTJ 504 from Huntsman Corp.), bi s(3 -aminopropyl) di ethylene glycol ether (available as ANCAMINE® 1922A from Evonik Industries AG in Essen, Germany), di(2-aminopropylated) diethylene glycol (available as JEFF AMINE® XTJ-511 from Huntsman Corp.), polypthylene oxide)methyl(3 -aminopropyl) ether, polypthylene glycol) diamine (available as JEFF AMINE® XTJ-512 from Huntsman Corp.), polypthylene oxide)bis(3- amino-propyl) ether and any mixtures and combination thereof. Poly (tetramethylene oxide) monoamines, diamines, and triamine include, for example, at least one of bis(3 -aminopropyl) polytetrahydrofuran (Mn350), bi s(3 -aminopropyl) polytetrahydrofuran (Mn750), poly (propylene oxide-block-tetramethylene oxide) bis(2-amino-2-methylethyl)ether (available as JEFF AMINE® XTJ-533, and JEFF AMINE® XTJ-536 from Huntsman Corp.) and mixtures and combinations thereof.

[0062] Some examples of cycloaliphatic amines as amine components of the coating composition include 1,2-diaminocyclohexane, l,3-diaminocyclohexane,l,4-diaminocyclohexane, hydrogenated ortho-toluenediamine, hydrogenated meta-toluenediamine, hydrogenated metaxylenediamine or 1,3 -bi spminom ethyl) cyclohexane (1,3-BAC), isophorone diamine (IPDA), norbomane diamines, 3,3'-dimethyl-4,4"-diaminodicyclohexyl methane, di(aminocyclohexyl) methane (including various isomers such as up to about 5 wt-% 2,4-(diaminocyclohexyl)methane and at least about 95 wt-% 4,4'-(diaminocyclohexyl)methane (available as AMICURE® PACM from Evonik Industries AG), l,3-di(aminocyclohexyl) propane, l-cyclohexylamino-3- amino-propane, di(aminocyclohexyl) sulfone, 4,4'-di(aminocyclohexyl) methane, 1- cy cl ohexylamino-3 -aminopropane, a mixture of methylene bridged poly(cyclohexyl-aromatic) amines, and the like, and mixtures and combinations thereof.

[0063] Some examples of aromatic polyamines as amine components of the coating composition include meta-phenylenediamine (MPD), para-phenylenediamine (PPD), diaminophenylmethane (DDM), tri(aminoethyl) benzene, tri(aminobutyl) naphthalene, toluene diamine(2-methyl-para- phenylenediamine), diethyl toluene diamine (DETDA), diaminodiphenyl sulfone (DDS), mixtures of methylene bridged poly(cyclohexyl-aromatic) amines, and mixtures and combinations thereof

[0064] Some examples of heterocyclic polyamines amine components of the coating composition include N-aminoethylpiperazine (NAEP), 3,9-bis(3-aminopropyl)- 2,4,8, 10-tetraoxaspiro[5.5]undecane, piperazine, 4,4'-trimethylene-dipiperidine, l,4-bis(3- aminopropyl) piperazine, 2, 5 -dimethylpiperazine, 2,6-dimethylpiperazine, 2-methylpiperazine, homopiperazine, and mixtures and combinations thereof.

[0065] Some examples of arylaliphatic polyamine amine components of the coating composition include m-xylylenediamine (MXDA), p-xylylenediamine, di(aminoethyl) benzene, tri(aminoethyl) benzene, tri(aminobutyl) naphthalene, and mixtures and combinations thereof.

[0066] Some examples of Mannich base amine components of the coating composition include polyamines derived from the reaction of the above-described aliphatic amines, cycloaliphatic amines, polyether amines, or aromatic amines with phenol or a substituted phenol and formaldehyde. An exemplary substituted phenol used to make Mannich bases with utility in the present disclosure is cardanol, which is obtained from cashew nut shell liquid. Alternatively, Mannich bases can be prepared by an exchange reaction of a multifunctional amine with at least one tertiary amine containing a Mannich base, such as 2,4,6-tris(N,N-dimethylaminomethyl) phenol (available as ANCAMINE® K54 from Evonik Industries AG). In some embodiments, the amine is or includes a tertiary amine containing phenol, that does not include reactive hydrogen groups. An example of such an amine is ANCAMINE® K54.

[0067] Some examples of amidoamine amine components of the coating composition include amiodoamines derived from a monobasic carboxylic acid and a polyamine such as an aliphatic amine, a cycloaliphatic amine, a heterocyclic amine, or an aromatic amine. The monobasic carboxylic acids are usually at least one of the C16, C18, and C19 type fatty acids derived from fats and oils, particularly from soya, tall oil, ricinoleic acids, and mixtures and combinations thereof. The polyamines may include, for example, DETA, TETA, TEPA, piperazine, alkylated, and benzylated amines. If desired, amidoamines can be modified by reacting a portion of the amine hydrogen with difunctional and monofunctional epoxy resins such as those described above. Amidoamines, as amine components of the coating composition, have the advantages over straight polyamines of reduced volatility and skin-irritation potential, more convenient mixing ratios, and increased flexibility and impact strength.

[0068] Higher temperatures during the synthesis of amidoamines usually lead to the formation of imidazoline structures derived from the ring closure of amine groups with amide groups. The ratio of amide and imidazoline depends on the reaction condition. The imidazoline moiety serves the function of improving wetting to the surface, thus improving adhesion, and also increasing the chemical and heat resistance of the cured product. Illustrative examples of amidoamines include amidoamines based on the reaction products of Cl 6, C18, and C19 type fatty acids, particularly tall oil fatty acid (TOFA) and TEPA, available as ANCAMIDE® 500, ANCAMIDE® 501, ANCAMIDE® 506, ANCAMIDE® 502, ANCAMIDE® 503, ANCAMIDE® 2447, or ANCAMIDE® 507 from Evonik Industries AG, and epoxy modified amidoamines such as ANCAMIDE® 2426 (available from Evonik Industries AG).

[0069] Additionally, some examples of di- and polyamines amine components in the present disclosure include, tris(aminophenyl) methane, bis(aminomethyl) norbomane, bis(aminopropyl) ether, bis(aminopropyl) sulfide, 4,4'-diaminodiphenyloxide, 3,3',5,5'-tetramethyl-4,4'- diaminodiphenyl, 3,3'-dimethyl-4,4'-diaminodiphenyl, 4,4'-diamino-alpha-methylstilbene, 4,4'- diaminobenzanilide, 4,4'-diaminostilbene, l,4-bis(4-aminophenyl)-trans-cyclohexane, 1, l-bis(4- aminophenyl) cyclohexane, 1, 4-bis(aminocy cl ohexyl) methane, l,4-bis(aminom ethyl) cyclohexane, 1,4-cyclohexanediamine, 2,2'-bis(4-aminocyclohexyl) propane, and any mixtures and combination thereof.

[0070] Examples of suitable commercially available amine components include CARDOLITE® NC-541 (available from Cardolite Corp, in Bristol, PA), CARDOLITE® LITE 2001 (available from Cardolite Corp.), SUNMIDE® CX-105X (available from Evonik Industries AG), EPIKURE™ 3140 (available from Westlake Epoxy), SIQ AMIN 2030 (available from S.I.Q. - Kunstharze GmbH in Marl, Germany), EPIKURE™ 3115X-70 (available from Westlake Epoxy), SIQ AMIN 2015 (available from S.I.Q. - Kunstharze GmbH), POLYPOX® VH 40309 / 12 (available from Polymer-Chemie GmbH in Bad Sobemheim, Germany), CETEPOX® 1490 H (available from Aditya Birla Advanced Materials in Mumbai, India), m-xylenediamine (MXDA, commercially available from Aalchem in Grand Rapids, MI), diethylaminopropylamine, GASKAMINE® 240 (available from Mitsubishi Gas Company Advanced Polymers, Inc. in Colonial Heights, VA), CARDOLITE® LITE 2002 (available from Cardolite Corp.), ARADUR® 42 BD (available from Huntsman Corp.), isophorone diamine (IPDA, commercially available from ThreeBond Co. Ltd. in Tokyo, Japan), EPIKURE™ 3090 (available from Westlake Epoxy), CRAYAMID® E260 E90 (available from Arkema Coating Resins in Torrance, CA), ARADUR® 943 CH (available from Huntsman Corp.), ARADUR® 863 XW 80 CA (available from Huntsman Corp.), diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), diproprenediamine (DPDA), diethylaminopropylamine (DEAPA), AMINE 248 (available from ThreeBond Co. Ltd.), N-aminoethylpiperazine (N-AEP), LAMIRON C-260 (available from ThreeBond Co. Ltd.), ARALDITE® HY-964 (available from Huntsman Corp.), menthane diamine (available from ThreeBond Co. Ltd.), 4,4'- methylenedicyclohexanamine (WAND AMIN HM, commercially available from ThreeBond Co. Ltd.), l,3-bis(aminomethyl) cyclohexane (1,3-BAC, commercially available from Mitsubishi Gas Company Advanced Polymers, Inc.), 1,3-diaminobenzene, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone (DDS), and mixtures and combinations thereof.

[0071] CATALYSTS

[0072] The coating composition may include one or more catalysts. The adjustment of the epoxy component material may suitably include the advancement of the molecular weight. The advancement of the molecular weight may be enhanced by the use of a catalyst. Typical catalysts usable in the advancement of the molecular weight of the epoxy component material of the coating compositions include amines, hydroxides (for example, potassium hydroxide and the like), phosphonium salts, and the like, and combinations thereof. In some embodiments, the catalyst is an amine catalyst. The catalyst may be present in an amount sufficient to facilitate the desired condensation reaction. For example, the catalyst may be present in an amount sufficient to facilitate the condensation reaction between bisphenol A and low epoxide equivalent weight epoxies, for example, EPON™ 828RS.

[0073] Some examples of catalysts suitable for the coating compositions include any conventional and modified tertiary amines, amine adducts, imidazoles, imidazole adducts, urea derivatives, all anionic, as well as Lewis acids, and onium salts, both cationic, may be used such as, for example, tertiary amines such as dimethylaminopyridine (DMAP), amine adducts such as EPIKURE™ P-100 granule (available from Westlake Epoxy), imidazoles such as 2- methylimidazole, imidazole adducts such as CUREDUCT™ P0505 (available from Shikoku Chemicals Corp, in Kagawa, Japan), and mixtures and combinations thereof.

[0074] In some embodiments, the coating composition includes one or more catalysts. In some embodiments, the coating composition includes an acid catalyst. Examples of acid catalysts include Lewis acids (for example, boron trifluoride etherate, and the like) and protic acids (such as Bronsted acids, and the like). In some embodiments, the acid catalyst is an inorganic protic acid, such as phosphoric acid or sulfuric acid, or an organic protic acid, such as carboxylic acid, phosphonic acid, or sulfonic acid, and the like. Exemplary carboxylic acids suitable for use as acid catalysts include, for example, acetic acid, trifluoroacetic acid, and propionic acid. An exemplary phosphonic acid is methylphosphonic acid. Exemplary sulfonic acids include, for example, methanesulfonic acid, benzenesulfonic acid, camphorsulfonic acid; paratoluenesulfonic acid (PTSA), and dodecylbenzenesulfonic acid (DBSA).

[0075] In some embodiments, the catalysts in the coating compositions include Lewis acids. Examples of suitable Lewis acid catalysts are aluminum trichloride (AlCh); benzyltriethylammonium chloride (TEBAC); CufChSCF ) ; (CFh^BrSBr; FeCh (for example, FeCh-6H20); HBF4; BF3-O(CH2CH3)2; TiCU; SnCl4; CrCh; NiCh; and Pd(OC(O)CH3)2. The acid catalyst may be unsupported (include no solid support) or supported, for example, covalently bonded to a solid support. In some embodiments, the catalysts in the coating compositions may include nitrogen bases. The nitrogen bases used as catalysts may be primary, secondary, or tertiary amines or basic nitrogen-containing heterocycles such as imidazoles. Thus, suitable bases include, for example, tertiary monoamines, secondary monoamines, primary, secondary, and tertiary diamines, tertiary triamines, mixed polyamines, and nitrogen heterocycles.

[0076] In some embodiments, the catalysts in the coating compositions include, for example, tertiary monoamines such as 2-(N,N-dimethylamino) ethanol, secondary monoamines such as diisobutylamine, primary diamines such as 1,3 -diaminopropane and 1,3-diaminobutane, secondary diamines such as piperazine, mixed polyamines such as 3 -(dimethylamino) propylamine, and nitrogen heterocycles such as 3 -methylpyridine or 4-m ethylpyridine, and the like. Examples of other bases include, tertiary monoamines such as tri-n-butylamine, tris-iso- butylamine, octyldimethylamine, benzyldimethylamine, tri-n-propylamine, trihexylamine, N,N- diethylcyclohexylamine, 2-(diethylamino) ethanol, 3 -(dimethylamino)- 1 -propanol and 2- (dimethylaminomethyl) phenol; secondary monoamines such as 2-(methylamino) ethanol, di-n- amylamine and diisoamylamine; primary diamines such as isophorone diamine (5-aminoethyl- 3,5,5-trimethylcyclohexylamine), 1,4-diaminobutane, 1,5-diaminopentane and hexamethylene diamine; secondary diamines such as N,N’ -di ethylene diamine; tertiary diamines such as N,N’,N’,N’ -tetramethylbutanediamine, l,7-bis(dimethylamino) heptane and bis(4- dimethylaminophenyl) methane; tertiary triamines such as 2,4,6-tris(dimethylaminomethyl) phenol; mixed polyamines such as triethylenetetramine, tetraethylenepentamine, diethylene triamine, 3-(diethylamino)propylamine, and N-(2-aminoethyl) piperazine; and nitrogen heterocycles such as 1 -methylimidazole, 2-methylimidazole, benzimidazole, 2-phenylimidazole, quinoline, benzyldimethylamine, and mixtures and combinations, thereof.

[0077] In some embodiments, the catalysts in the coating compositions include a tertiary amine. In some embodiments, the tertiary amine is 2,4,6-tris(dimethylaminomethyl) phenol, commercially available as ANCAMINE® K54 from Evonik Industries AG.

[0078] Catalysts may be present in any amount that suitably accelerates the curing of the epoxyamine coating. In some embodiments, a catalyst may be present in amounts of 0.5 wt-% or more, 1 wt-% or more, 2 wt-% or more, 3 wt-% or more, 4 wt-% or more, 5 wt-% or more, 8 wt-% or more, 10 wt-% or more, 12 wt-% or more, 15 wt-% or more, or 18 wt-% or more, based on weight of the hardener composition. In some embodiments, a catalyst may be present in an amount of 20 wt-% or less, 15 wt-% or less, 15 wt-% or less, 12 wt-% or less, 10 wt-% or less, 8 wt-% or less, 5 wt-% or less, 4 wt-% or less, 3 wt-% or less, or 2 wt-% or less.

[0079] ADDITIVES

[0080] The coating compositions of the present disclosure may optionally include one or more additives. When used, the additives preferably enhance and preferably do not adversely affect the coating composition or a cured coating formed from the coating composition. For example, additives may be included in the coating composition to enhance coating aesthetics, facilitate manufacturing, processing, handling, or application of the composition, and to further improve a particular functional property of the coating composition or a cured coating resulting therefrom. Such optional additives include, for example, dyes, pigments, toners, extenders, fillers, lubricants, anticorrosion agents, flow control agents, thixotropic agents, dispersing agents, antioxidants, adhesion promoters, light stabilizers, co-resins and mixtures thereof. Each optional additive is preferably included in a sufficient amount to serve its intended purpose but not in such an amount as to adversely affect the coating composition or a cured coating resulting therefrom.

[0081] When used, fillers may be present in any useful amount and can be determined by those of ordinary skill in the art using this document as guidance. Typically, fillers may be present at a concentration of 0 wt-% or more, 0.5 wt-% or more, 1 wt-% or more, 2 wt-% or more, 3 wt-% or more, 4 wt-% or more, 5 wt-% or more, 8 wt-% or more, 10 wt-% or more, 12 wt-% or more, 15 wt-% or more, 20 wt-% or more, 25 wt-% or more, or 30 wt-% or more, of the coating composition. Fillers may be present at a concentration of 35 wt-% or less, 30 wt-% or less, 25 wt-% or less, 20 wt-% or less, 15 wt-% or less, 12 wt-% or less, 10 wt-% or less, 8 wt-% or less, 5 wt-% or less, 4 wt-% or less, 3 wt-% or less, 2 wt-% or less, 1 wt-% or less, or 0.5 wt-% or less, of the coating composition.

[0082] In some embodiments, fillers may be optionally used. Some examples of optional fillers include mineral fillers, such as calcium carbonate, calcium oxide, and talc. Calcium carbonate (for example, sold under the trade name OMYA®, available from Omya, Inc. in Proctor, VT) can be used, for example, to reduce shrinkage and increase corrosion resistance. Talc is available, for example, under the trade name MISTROFIL® (available from Evonik Industries AG), and aluminum magnesium silicate (wollastonite) is commercially available, for example, under the trade name NY AD® 200 (available from Imerys S. A. in Paris, France).

[0083] When used, pigments may be present in any useful amount and can be determined by those of ordinary skill in the art using this document as guidance. Typically, pigments may be present in at a concentration of 0 wt-% or more, 0.5 wt-% or more, 1 wt-% or more, 2 wt-% or more, 3 wt-% or more, 4 wt-% or more, 5 wt-% or more, 8 wt-% or more, 10 wt-% or more, 12 wt-% or more, or 15 wt-% or more, of the coating composition. Pigments may be present at a concentration of 20 wt-% or less, 15 wt-% or less, 12 wt-% or less, 10 wt-% or less, 8 wt-% or less, 5 wt-% or less, 4 wt-% or less, 3 wt-% or less, 2 wt-% or less, 1 wt-% or less, or 0.5 wt-% or less, of the coating composition.

[0084] In some embodiments, thixotropic agents and other viscosity regulators may also be optionally used. One such example includes fumed silica (for example, sold under the trade name AEROSIL,® commercially available from Evonik Industries AG). An example of a thixotropic agent that also improves wash-off resistance is a mixture of polyester and liquid epoxy resin (LER), such as DYNACOLL® (available from Evonik Industries AG).

[0085] Another useful optional additive is a lubricant, which facilitates the manufacture of coated articles by imparting lubricity to coated substrates. Examples of lubricants include, for example, carnauba wax and polyethylene-type lubricants. In some embodiments, a lubricant, if used, is present in the coating composition in an amount of at least about 0.1 wt-%, and no greater than about 2 wt-%, or no greater than about 1 wt-%, based on the total solids weight of the coating composition. Castor oil waxes with polyamides may also be used and are commercially available under the trade name RHEOTIX, (for example, RHEOTIX 240 commercially available from BYK-Chemie, GmbH in Wesel, Germany). Other suitable gelling agents include, for example, LUVOTIX® grades, such as LUVOTIX® HT (available from LEHVOSS North America, LLC, in Pawcatuck, CT), which is a polyamide without the wax, or DISPARLON grades (available from King Industries in Norwalk, CT).

[0086] Another useful optional additive is an organosilicon material, such as siloxane-based or polysilicon-based materials.

[0087] In some embodiments, fumed silica, when used, may be present in amounts 2 wt-% or more, 4 wt-% or more, 6 wt-% or more, 8 wt-% or more, 10 wt-% or more, 12 wt-% or more, or 14 wt-% or more, of the epoxy component. Fumed silica may be present in amounts 15 wt-% or less, 12 wt-% or less, 10 wt-% or less, 8 wt-% or less, 6 wt-% or less, or 4 wt-% or less, of the epoxy component.

[0088] The coating compositions of the present disclosure may optionally include reactive and non-reactive diluents. In some embodiments, a reactive diluent is blended with the epoxy component material. The reactive diluents useful in the coating compositions of the present disclosure are also capable of undergoing a reaction to form a polymer, described as an interpenetrating network with the epoxy component or with unsaturated moieties that may optionally be present. In some embodiments, reactive diluents suitable for use in the coating compositions of the present disclosure include free-radical reactive monomers and oligomers. A small amount of reactive diluent that can undergo reaction with the epoxy component may be used, including, for example, hydroxy monomers such as 2-hydroxy ethylmethacrylate, amide monomers such as acrylamide, and N-methylol monomers such as N-methylol acrylamide, and the like. Additional examples of reactive diluents include vinyl compounds, acrylate compounds, methacrylate compounds, acrylamides, acrylonitriles, and the like.

[0089] In some embodiments, the reactive diluent functions as a solvent or otherwise lowers the viscosity of the blend of reactants. The use of one or more reactive diluents as a “solvent” eliminates or reduces the need to incorporate a substantial amount of other cosolvents (such as butanol) during processing. A wide variety of cosolvents are suitable for use in the coating compositions of the present disclosure. The use of cosolvents, however, may contribute to an undesirable high level of volatile organic compounds that would have to be removed or recovered. A careful selection of cosolvents useable in the coating compositions of the present disclosure is desirable to provide a coating composition having a low volatile organic compound content. Typical cosolvents useful in the coating compositions of the present disclosure include, for example, organic materials, such as xylene, toluene, butanol, 2-butoxyethanol, amyl alcohol, and 2-hexyloxyethanol, and the like. Some examples of cosolvents include 2-hexyloxyethanol (hexyl CELLOSOLVE™ commercially available from Dow Inc.), amyl alcohol, and the like. Cosolvents may be usable in the coating compositions of the present disclosure, for example, to enhance the dissolution of the reactive diluent and / or improve the performance of the reactive diluent as a solvent for the other ingredients. An example of a reactive diluent monoglycidyl ester of neodecanoic acid, which may also act as a viscosity -reducing agent. It is commercially available, for example, under the trade name ERISYS GS-110 (available Huntsman Corp.)

[0090] In some embodiments, adhesion promoters may also be optionally used. Examples of adhesion promoters include epoxy silanes, for example, SILQUEST™ A- 187 (available from Momentive Performance Materials Inc. in Niskayuna, NY). In some embodiments, a surfactant or wetting agent may be optionally used. A wetting agent may be, for example, a non-ionic fluorinated polymer. In some embodiments, such agents are also capable of absorbing residual oils (for example, manufacturing and processing oils) on metal surfaces, thereby facilitating adhesion to metal surfaces.

[0091] In some embodiments, at least one aliphatic substituted phenol may be optionally used. Examples of aliphatic substituted phenol include a phenol derivative with an aliphatic group in the meta-position, for example, cardanol. Such compounds promote adhesion and corrosion resistance. Cardanol is commercially available, for example, under the trade name CARDOLITE® NC 700 (available from Cardolite Corp.).

[0092] Some non-limiting examples of other additives include flexible epoxy resins such as fatty acid epoxy adducts, gelling compounds such as polyester or PVB, and flame retardants such as aluminum-tris-hydroxide. Pigments or coloring agents, for example, IRGALITE® green (available from IMCD US, LLC in Oakland, CA) or ARALDITE® blue (available from Huntsman Corp.), may also be used.

[0093] METHODS

[0094] According to an embodiment, a method of coating includes applying the coating composition to an article and curing the coating composition to form a cured coating. The coating composition may be applied to any article that may benefit from being coated with the cured coating. In some embodiments, the coating compositions of the present disclosure are useful to coat pipes, chemical tanks (holding and process tanks), pipelines, connectors, etc., as substrates. In a preferred embodiment, the substrate is made of steel.

[0095] Mixing of the epoxy component, the amine component, catalysts, and any additives to form the epoxy-amine coating composition of the present disclosure can be in any order and by any appropriate means known in the art. The mixing may be accomplished according to any known method for mixing, including, for example, mixing by magnetic stirrers, high shear mixing, hand mixing, mechanical mixing, or other suitable mixing methods.

[0096] In one embodiment, the present disclosure provides a coating composition that includes: providing an epoxy component, an amine component, and a catalyst; and mixing them together. The method includes reacting the epoxy component with the amine component.

[0097] The coating composition may be applied by any suitable processes known in the art. The processes to apply the coating composition to an article include, for example, sheet coating, coil coating, roll coating, spray coating, draw down bar, brush, and the like. In some embodiments, the coating composition is applied by spray coating.

[0098] In some embodiments, applying coating to the article may be accomplished by direct roll coating. The coated articles may be cured by any suitable means known in the art. In some embodiments, the coated articles may be cured by feeding through a forced draft, gas-fired, or any suitable oven. Alternatively (or in addition), the coated articles may be fed through a vacuum chamber to remove any solvents present in the coating composition. Other coating processes are also usable and may depend on the equipment and processing capabilities.

[0099] After the coating composition is applied to the article, the coating composition is cured at an elevated temperature within a limited amount of time from the application of the coating composition. The coating composition may be cured within 60 minutes, within 45 minutes, within 30 minutes, within 20 minutes, within 15 minutes, within 10 minutes, or within 5 minutes of the application of the coating composition. The coating composition may be cured without any substantial delay after the application of the coating composition.

[0100] The coating composition may be cured at an elevated temperature that is effective for curing the coating composition. The coating composition may be cured at a temperature of 70 °C or greater, 80 °C or greater, 90 °C or greater, 100 °C or greater, 110 °C or greater, 120 °C or greater, 130 °C or greater, 140 °C or greater, 150 °C or greater, 160 °C or greater, 175 °C or greater, 200 °C or greater, or 225 °C or greater. The coating composition may be cured at a temperature of 250 °C or lower, 225 °C or lower, 200 °C or lower, 175 °C or lower, 160 °C or lower, 150 °C or lower, 140 °C or lower, 130 °C or lower, 120 °C or lower, 110 °C or lower, 100 °C or lower, 90 °C or lower, or 80 °C or lower. The coating composition may be cured at a temperature of 135 °C to 250 °C, 150 °C to 225 °C, or 175 °C to 200 °C. The curing time may be selected based on the speed of the curing reaction. For example, the curing time may be selected such that the coating composition is fully cured at the end of the curing time. In some embodiments, the curing time may be 60 min or greater, 90 min or greater, 120 min or greater, 150 min or greater, 180 min or greater, 240 min or greater, 300 min or greater, 360 min or greater, 420 min or greater, or 540 min or greater. The curing time may be 600 min or less, 540 min or less, 420 min or less, 360 min or less, 300 min or less, 240 min or less, 180 min or less, 150 min or less, 120 min or less, or 90 min or less.

[0101] According to an embodiment, the coating is cured in a manner that effects a homopolymerization cure prior to any epoxy-amine curing.

[0102] COATINGS AND ARTICLES

[0103] The cured coatings prepared as described above may include epoxy homopolymer segments. The cured coatings may include epoxy homopolymer segments with repeating units separated by ether linkages.

[0104] According to an embodiment, the cured coating prepared as described above, includes epoxy homopolymer segments that are longer than corresponding epoxy segments in coatings of the prior art. The number of repeating units of the epoxy homopolymer segments and the epoxyamine units in the cured coating may be given as a calculated average. That is, although the number of repeating units is an integer, the calculated average may be a decimal number. The cured coating may include epoxy homopolymer segments comprising 1.5 or more repeating units, 1.6 or more repeating units, 1.7 or more repeating units, 1.8 or more repeating units, 1.9 or more repeating units, 2 or more repeating units, 2.1 or more repeating units, or 2.2 or more repeating units, separated by ether linkages. An exemplary schematic of the curing reaction of an epoxy component and diamine is shown below. The epoxy homopolymer segment has n repeating units, and the polymer has m repeating units of epoxy-amine. The repeating units of epoxy-amine within the polymer may vary. post-cure epoxy-amine coating where R1and R2are independently an organic group (e.g., an aliphatic group, a cycloaliphatic group, or an aromatic group); n is 1.5 or greater, 1.6 or greater, 1.7 or greater, 1.8 or greater, 1.9 or greater, 2 or greater, 2.1 or greater, or 2.2 or greater; and m is 15. or greater, 1.6 or greater, 1.7 or greater, 1.8 or greater, 1.9 or greater, 2 or greater, 2.1 or greater, or 2.2 or greater.

[0105] The polymer of the cured coating may have any suitable backbone chemistry and may be a linear or branched polymer.

[0106] According to an embodiment, the cured coating exhibits a high gloss rating. A high gloss rating of a coating is indicative of superior reflective properties of the coating. The gloss rating may be determined by the standard ASTM D523-14 specular gloss test as described by the international standards organization, American Society for Testing and Materials (ASTM). The cured coating may exhibit a gloss rating of 60 Gloss Units (GU) or higher at 60 degrees incident light, 70 GU or higher at 60 degrees incident light, 80 GU or higher at 60 degrees incident light, 90 GU or higher at 60 degrees incident light, or 100 GU or higher at 60 degrees incident light, where a gloss unit is the ratio of light specularly reflected to the total light reflected wherein specularly reflected light is one wherein the angle of incidence equals the angle of reflection. While there is no desired upper limit for the gloss rating, in practice, gloss ratings are typically below 100 GU.

[0107] The cured coating may exhibit a high solvent resistance. Solvent resistance may be determined using the standard ASTM D5402-19 MEK double rub test as described by the international standards organization, American Society for Testing and Materials (ASTM).

[0108] The performance of the cured coating may be tested using a rub test. The cured coating may exhibit a rub test result of 40 or more double rubs (i.e., one back-and-forth motion), 50 or more double rubs, 60 or more double rubs, 70 or more double rubs, or 80 or more double rubs. While there is no desired upper limit for the rub test result, in practice, the rub test results are typically below 200 double rubs.

[0109] The performance of the cured coating may also be tested by evaluating the resistance of the coating towards corrosion via a salt fog test (also called salt spray test). A standard salt fog test may be performed according to ASTM B 117 as described by the international standards organization, American Society for Testing and Materials (ASTM). In this test, the coated test substrate is scribed with a knife to expose the bare metal of the substrate. The scribed substrate is placed into a test chamber maintained at a constant temperature where an aqueous salt solution is continuously misted onto the substrate. The coated substrate is exposed to the salt spray environment for a specified period of time, such as 500 or 1000 hours. After exposure, the coated substrate is removed from the test chamber and evaluated for corrosion along the scribe. Corrosion is measured by “scribe creep,” which is defined as the total distance the corrosion has traveled across the scribe measured in millimeters. The cured coating may exhibit a scribe creep of 0 mm or greater, 0.5 mm or greater, 1 mm or greater, 2 mm or greater, 3 mm or greater, 4 mm or greater, or 5 mm or greater. The cured coating may exhibit a scribe creep of 6 mm or less, 5 mm or less, 4 mm or less, 3 mm or less, 2 mm or less, 1 mm or less, or 0.5 mm or less. The cured coating may exhibit a scribe creep of 0 to 6 mm.

[0110] The present disclosure also provides articles coated with the cured coating as described above.

[0111] EXEMPLARY EMBODIMENTS

[0112] Exemplary embodiments according to the present disclosure are provided below. The numbering of the exemplary aspects is not to be construed as designating levels of importance.

[0113] Embodiment 1 is a method of coating an article, the method comprising: preparing a coating composition comprising: an epoxy component; an amine component; and a catalyst; the epoxy component and the amine component being present in the coating composition at the ratio of 0.8:1 to 1.5: 1; applying the coating composition onto the article; and within 60 minutes of the applying, curing the coating composition at a temperature of 135 degrees C to 250 degrees C to form a cured coating having a gloss rating of 60 Gloss Units (GU) or higher. Embodiment 2 is the method of embodiment 1, wherein the cured coating comprises epoxy homopolymer segments comprising 2 or more repeating units separated by ether linkages.

[0114] Embodiment 3 is the method of embodiment 1 or 2, wherein the epoxy component has a molecular weight range of 175 Daltons to 1200 Daltons.

[0115] Embodiment 4 is the method of any one of embodiments 1 to 3, wherein the epoxy component has a molecular weight range of 200 Daltons to 350 Daltons.

[0116] Embodiment 5 is the method of any one of embodiments 1 to 4, wherein the stoichiometric ratio of the epoxy component to the amine component is from 1 :1 to 5: 1.

[0117] Embodiment 6 is the method of any one of embodiments 1 to 5, wherein the epoxy component comprises 1 to 5 epoxide groups.

[0118] Embodiment 7 is the method of any one of embodiments 1 to 6, wherein the epoxy component comprises at least two different epoxy resins.

[0119] Embodiment 8 is the method of any one of embodiments 1 to 7, wherein the amine component comprises at least two different amine components.

[0120] Embodiment 9 is the method of any one of embodiments 1 to 8, wherein the catalyst comprises at least two catalysts.

[0121] Embodiment 10 is the method of any one of embodiments 1 to 9, wherein the coating composition comprises 100 wt-% solids by weight of the coating composition.

[0122] Embodiment 11 is the method of any one of embodiments 1 to 10, wherein the curing the coating composition is done by heating the coating from a temperature of about 150 degrees C to about 225 degrees C.

[0123] Embodiment 12 is the method of any one of embodiments 1 to 11, wherein the cured coating exhibits a rub test result of 50 double rubs or higher.

[0124] Embodiment 13 is the method of any one of embodiments 1 to 12, wherein the coating composition comprises less than 1 wt-% organic solvents by weight of the coating composition.

[0125] Embodiment 14 is an article coated with the cured coating of any one of the preceding embodiments. Embodiment 15 is a composition comprising: a cured coating made by: preparing a coating composition comprising: an epoxy component; an amine component; and a catalyst; applying the coating composition onto the article; and within 60 minutes of the applying, curing the coating composition to form the cured coating.

[0126] Embodiment 16 is the composition of embodiment 15, wherein the curing is done at a temperature of 135 degrees C to 250 degrees C.

[0127] Embodiment 17 is the composition of embodiment 15 or 16, wherein the cured coating has a gloss rating of 60 Gloss Units (GU) or higher.

[0128] Embodiment 18 is the composition of any one of embodiments 15 to 17, wherein the cured coating comprises epoxy homopolymer segments comprising 2 or more repeating units separated by ether linkages.

[0129] Embodiment 19 is the composition of any one of embodiments 15 to 18, wherein the epoxy component has a molecular weight range of 175 Daltons to 1200 Daltons.

[0130] Embodiment 20 is the composition of any one of embodiments 15 to 19, wherein the epoxy component has a molecular weight range of 200 Daltons to 350 Daltons.

[0131] Embodiment 21 is the composition of any one of embodiments 15 to 20, wherein the stoichiometric ratio of the epoxy component to the amine component is from 1 :1 to 5: 1.

[0132] Embodiment 22 is the composition of any one of embodiments 15 to 21, wherein the epoxy component comprises 1 to 5 epoxide groups.

[0133] Embodiment 23 is the composition of any one of embodiments 15 to 22, wherein the epoxy component comprises at least two different epoxy resins.

[0134] Embodiment 24 is the composition of any one of embodiments 15 to 23, wherein the amine component comprises at least two different amine components. Embodiment 25 is the composition of any one of embodiments 15 to 24, wherein the catalyst comprises at least two catalysts.

[0135] Embodiment 26 is the composition of any one of embodiments 15 to 25, wherein the coating composition comprises 100 wt-% solids by weight of the coating composition.

[0136] Embodiment 27 is the composition of any one of embodiments 15 to 26, wherein the curing the coating composition is done by heating the coating from a temperature of about 150 degrees C to about 225 degrees C.

[0137] Embodiment 28 is the composition of any one of embodiments 15 to 26, wherein the cured coating exhibits a rub test result of 50 double rubs or higher.

[0138] Embodiment 29 is the composition of any one of embodiments 15 to 28, wherein the coating composition comprises less than 1 wt-% organic solvents by weight of the coating composition.

[0139] Embodiment 30 is an article comprising: a body; and a cured coating disposed on the body, the cured coating made by: preparing a coating composition comprising: an epoxy component; an amine component; and a catalyst; applying the coating composition onto the article; and within 60 minutes of the applying, curing the coating composition to form the cured coating.

[0140] Embodiment 31 is the article of embodiment 30, wherein the curing is done at a temperature of 135 degrees C to 250 degrees C.

[0141] Embodiment 32 is the article of embodiment 30 or 31, wherein the cured coating has a gloss rating of 60 Gloss Units (GU) or higher.

[0142] Embodiment 33 is the article of any one of embodiments 30 to 32, wherein the cured coating comprises epoxy homopolymer segments comprising 2 or more repeating units separated by ether linkages. Embodiment 34 is the article of any one of embodiments 30 to 33, wherein the epoxy component has a molecular weight range of 175 Daltons to 1200 Daltons.

[0143] Embodiment 35 is the article of any one of embodiments 30 to 34, wherein the epoxy component has a molecular weight range of 200 Daltons to 350 Daltons.

[0144] Embodiment 36 is the article of any one of embodiments 30 to 35, wherein the stoichiometric ratio of the epoxy component to the amine component is from 1 :1 to 5: 1.

[0145] Embodiment 37 is the article of any one of embodiments 30 to 36, wherein the epoxy component comprises 1 to 5 epoxide groups.

[0146] Embodiment 38 is the article of any one of embodiments 30 to 37, wherein the epoxy component comprises at least two different epoxy resins.

[0147] Embodiment 39 is the article of any one of embodiments 30 to 38, wherein the amine component comprises at least two different amine components.

[0148] Embodiment 40 is the article of any one of embodiments 30 to 39, wherein the catalyst comprises at least two catalysts.

[0149] Embodiment 41 is the article of any one of embodiments 30 to 40, wherein the coating composition comprises 100 wt-% solids by weight of the coating composition.

[0150] Embodiment 42 is the article of any one of embodiments 30 to 41, wherein the curing the coating composition is done by heating the coating from a temperature of about 150 degrees C to about 225 degrees C.

[0151] Embodiment 43 is the article of any one of embodiments 30 to 42, wherein the cured coating exhibits a rub test result of 50 double rubs or higher.

[0152] Embodiment 44 is the article of any one of embodiments 30 to 43, wherein the coating composition comprises less than 1 wt-% organic solvents by weight of the coating composition.

[0153] EXAMPLES

[0154] Various coatings were prepared according to embodiments of the present disclosure. The performance of the coatings was evaluated and compared to a control. Example 1

[0155] A coating composition was prepared according to TABLE 1 A below and was applied to sample substrates Sample 1, Sample 2, Comparative Sample 1C, Comparative Sample 2C, and Comparative Sample 3C. Preparation of the epoxy-amine coating composition:

[0156] TABLE 1A.

[0157] A tank (Tank-1, 1000 gallons) equipped with a stirrer was charged with the calculated amount of diglycidyl ether of bisphenol A (DGBA) resin EPON™ 828LS, followed by the addition of a leveling additive with defoaming properties BYK 077, and a rheology modifier SUSPEND 201 NBA wax. Next, solvent xylene was added along with a viscosity and leveling agent MODAFLOW.® Partially n-butylated urea cross-linking agent CYMEL® U-216, available commercially in a mixture of n-butanol and xylene, was added to the reaction mixture in the tank. For improved coating performance, a microcrystalline talc MISTRON Monomix was added to the tank, along with a micronized functional filler MINEX® 7 and a calcium carbonate additive OMYACARB® 3. An anti-settling and thickening agent AEROSIL 200 Fumed Silica, was also added to the reaction vessel. To provide color to the coating, synthetic red iron oxide was added to the mixture along with additional color pigment additive RAVEN® 1035 powder. Finally, a low-viscosity, mono-functional epoxy reactive diluent was added to the reaction mixture along with n-butyl alcohol as a co-solvent. The contents of Tank- 1 were then mixed thoroughly with the equipped stirrer.

[0158] Another suitably sized tank (Tank-2, 200-gallons) equipped with a stirrer, was charged with calculated amounts of a modified aliphatic amine component ANCAMINE® 2089M and a polyamidoimidazoline amine component ARADUR® 140 BDB. Benzyl alcohol is added as solvent. 2,4,6-Tris(dimethylaminomethyl) phenol, available commercially as ANCAMINE® K54, is then added as the catalyst of choice. The mixture in Tank-2 is stirred vigorously with the stirrer for thorough mixing of the contents of the tank.

[0159] The contents of Tank-1 and Tank-2 were mixed. The mixture was then applied to flat steel panel substrates, Sample 1, Sample 2, Comparative Sample 1C, Comparative Sample 2C, and Comparative Sample 3C.

[0160] Sample 1 was placed in an oven set to 90 °C (194 °F) within an hour of the application of the mixture. Sample 1 was cured for 4 hours.

[0161] Sample 2 was placed in an oven set to 110 °C (230 °F) within an hour of the application of the mixture. Sample 2 was cured for 2.5 hours.

[0162] Comparative Sample 1C was allowed to dry at room temperature for 24 hours and was then placed in an oven set to 90 °C (194 °F). Comparative Sample 1C was cured for 4 hours.

[0163] Comparative Sample 2C was allowed to dry at room temperature for 24 hours and was then placed in an oven set to 110 °C (230 °F). Comparative Sample 2C was cured for 2.5 hours.

[0164] Comparative Sample 3C was allowed to dry at room temperature for 24 hours and was then placed in an oven set to 110 °C (230 °F). Comparative Sample 3C was cured for 4 hours.

[0165] The quality of the cured coating on the Sample 1, Sample 2, Comparative Sample 1C, Comparative Sample 2C, and Comparative Sample 3C was evaluated according to the standard ASTM D5402-19 solvent rubs test, and the standard ASTM D523-14 specular gloss test, as described by the international standards organization, American Society for Testing and Materials (ASTM). The results are shown in TABLE IB below.

[0166] TABLE IB.

[0167] Surprisingly, it was observed that Sample 1 and Sample 2 displayed excellent characteristics in the gloss test with values of 100 and 82.1 GU, respectively. The comparative samples 1C, 2C, and 3C displayed gloss ratings of only 32.1 GU, 10.8 GU, and 7.2 GU, respectively. Similar superior characteristics were observed in the solvent rubs test. Sample 1 and Sample 2 outperformed the comparative samples 1C, 2C, and 3C with far superior resistance to solvent rubs values for both Sample 1 and Sample 2.

[0168] Example 2

[0169] An exemplary coating according to embodiments of the present application may be prepared from the ingredients in TABLE 2 below.

[0170] TABLE 2.

[0171] The composition may be prepared and applied as a coating as described herein. For example, the composition may be prepared and applied as a coating as described in Example 1. All references and publications cited herein are expressly incorporated herein by reference in their entirety into this disclosure, except to the extent they may directly contradict this disclosure. Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and / or equivalent implementations can be substituted for the specific embodiments shown and described without departing from the scope of the present disclosure. It should be understood that this disclosure is not intended to be unduly limited by the illustrative embodiments and examples set forth herein and that such examples and embodiments are presented by way of example only with the scope of the disclosure intended to be limited only by the claims set forth here.

Claims

CLAIMS1. A method of coating an article, the method comprising: preparing a coating composition comprising: an epoxy component; an amine component; and a catalyst; the epoxy component and the amine component being present in the coating composition at the ratio of 0.8:1 to 1.5: 1; applying the coating composition onto the article; and within 60 minutes of the applying, curing the coating composition at a temperature of 135 degrees C to 250 degrees C to form a cured coating having a gloss rating of 60 Gloss Units (GU) or higher.

2. The method of claim 1, wherein the cured coating comprises epoxy homopolymer segments comprising 2 or more repeating units separated by ether linkages.

3. The method of claim 1, wherein the epoxy component has a molecular weight range of 175 Daltons to 1200 Daltons.

4. The method of claim 1, wherein the epoxy component has a molecular weight range of 200 Daltons to 350 Daltons.

5. The method of claim 1, wherein the stoichiometric ratio of the epoxy component to the amine component is from 1 : 1 to 5 : 1.

6. The method of claim 1, wherein the epoxy component comprises 1 to 5 epoxide groups.

7. The method of claim 1, wherein the epoxy component comprises at least two different epoxy resins.

8. The method of claim 1, wherein the amine component comprises at least two different amine components.

9. The method of claim 1, wherein the catalyst comprises at least two catalysts.

10. The method of claim 1, wherein the coating composition comprises 100 wt-% solids by weight of the coating composition.

11. The method of claim 1, wherein the curing the coating composition is done by heating the coating from a temperature of about 150 degrees C to about 225 degrees C.

12. The method of claim 1, wherein the cured coating exhibits a rub test result of 50 double rubs or higher.

13. The method of claim 1, wherein the coating composition comprises less than 1 wt-% organic solvents by weight of the coating composition.

14. An article coated with the cured coating of any one of the preceding claims.

15. A composition comprising: a cured coating made by: preparing a coating composition comprising: an epoxy component; an amine component; and a catalyst; applying the coating composition onto the article; and within 60 minutes of the applying, curing the coating composition to form the cured coating.

16. An article comprising: a body; and a cured coating disposed on the body, the cured coating made by: preparing a coating composition comprising: an epoxy component; an amine component; and a catalyst; applying the coating composition onto the article; and within 60 minutes of the applying, curing the coating composition to form the cured coating.

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