Crosslinkable coating system and coatings prepared therefrom

Abstract

A crosslinkable coating system, a method for coating an article with the crosslinkable coating system, and an article coated with the crosslinkable coating system are provided. The coating system includes a urea component and an aldehyde containing two or more carbon atoms. The coating system may include a solvent. The coating system may be free or substantially free of formaldehyde and isocyanate. The coating system may include a reaction product of a urea component and an aldehyde containing two or more carbon atoms. The coating system may be in powder form.

Description

[Technical Field]

[0001] The present disclosure relates generally to crosslinkable coating systems. The present disclosure further relates to methods of coating articles with crosslinkable coating systems and to articles coated therewith. Summary of the Invention

[0002] In some embodiments, the coating system includes a urea component, an aldehyde containing two or more carbon atoms, and a solvent. The urea component may be present in a molar ratio of 0.5 to 2.5 moles per mole of aldehyde. The urea component may be represented by the following formula (I):

[0003] [ka] In the formula, R 1 , R 2 , R 3 , and R 4 are independently H or a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R 1 , R 2 , R 3 , and R 4 is independently H or an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group; R 1 , R 2 , R 3 , and R 4 at least one of is H; R 1 , R 2 , R 3 , and R 4 Any two of may be joined together to form a cyclic group.

[0004] The aldehyde may be represented by the following formula (II) or (IIA):

[0005] [ka] In the formula, R 5 is a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R 5 is an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group, and optionally the aldehyde is in a protected form, including an acetal or hydrate. The aldehyde may be a monoaldehyde. The aldehyde may be a polyaldehyde. The aldehyde may be an oligomer. Also, each R 6 and R 7 are independently carbon-containing groups optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or combinations thereof, and preferably each R 6 and R 7 is independently an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, alkylamine, or urea group. 6 and R 7 may independently be straight-chained, branched-chained, or cyclic and may contain zero, one, or more double bonds. 6 and R 7 may independently contain any suitable number of carbon atoms. In some embodiments, each R 6 and R 7 may independently be an oligomer or a polymer. In a preferred embodiment, R 6 and R 7are independently a carbon-containing group having 1 to 4 carbon atoms. In some preferred embodiments, R on the acetal of formula (IIA) 6 and R 7 The group is R 6 =R 7 In some embodiments, R 6 and R 7 can be linked to form a cyclic acetal.

[0006] The urea component and the aldehyde may form a reaction product represented by the following formula (III):

[0007] [ka] In the formula, R 1 is a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R 1 is an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group; R 5 is the same as formula (II).

[0008] The urea component and the aldehyde may form a further reaction product represented by formula (IV):

[0009] [ka] In the formula, R 1 is a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R 1is an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group; R 5 is the same as formula (II).

[0010] The coating system may be free or substantially free of formaldehyde.The coating system may be free or substantially free of isocyanates.

[0011] The coating system may be curable at a temperature of 60°C or less, 50°C or less, 40°C or less, 30°C or less, or 25°C or less.

[0012] In some embodiments, the coating system comprises the reaction product of a urea component and an aldehyde containing two or more carbon atoms.

[0013] The reaction product may be a crosslinked product of formula (III):

[0014] [ka] In the formula, R 1 is a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R 1 is an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group; R 5 is the same as formula (II).

[0015] The reaction product may be a crosslinked product of formula (IV):

[0016] [ka] In the formula, R 1 is a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R 1 is an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group; R 5 is the same as formula (II).

[0017] The coating system may be in powder form.

[0018] The coating system may include an organic solvent, water, or both.

[0019] The coating system may be free or substantially free of formaldehyde and structural units derived from formaldehyde.The coating system may be free or substantially free of isocyanates and structural units derived from isocyanates.

[0020] The present disclosure further provides articles coated with the coating systems. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is an NMR spectrum of the sample produced in Example 1, according to one embodiment. [Figure 2] 1 is an NMR spectrum of the sample produced in Example 3, according to one embodiment. [Figure 3] 1 is an NMR spectrum of the sample produced in Example 4, according to one embodiment. [Figure 4] 1 is an NMR spectrum of the intermediate product produced in Example 5, according to one embodiment. [Figure 5]1 is an NMR spectrum of the final sample produced in Example 6, according to one embodiment. [Figure 6] 1 is an NMR spectrum of the sample produced in Example 7, according to one embodiment. [Figure 7] 1 is an NMR spectrum of the sample produced in Example 8, according to one embodiment. [Figure 8] 1 is an NMR spectrum of the sample produced in Example 9, according to one embodiment. [Figure 9] 1 is an NMR spectrum of the intermediate product produced in Example 10, according to one embodiment. [Figure 10] 1 is an NMR spectrum of the final sample produced in Example 12, according to one embodiment. [Figure 11] 1 is an NMR spectrum of the sample produced in Example 13, according to one embodiment. [Figure 12] 1 is an NMR spectrum of the sample produced in Example 15, according to one embodiment. [Figure 13] 1 is an NMR spectrum of the sample produced in Example 24, according to one embodiment.

[0022] definition All scientific and technical terms used herein have meanings commonly used in the art unless otherwise specified. The definitions provided herein are intended to facilitate understanding of certain terms used frequently herein and are not meant to limit the scope of the present disclosure.

[0023] Unless otherwise indicated, the terms "polymer" and "polymeric material" include, but are not limited to, organic homopolymers, copolymers such as block, graft, random and alternating copolymers, terpolymers, and the like, as well as blends and modifications thereof. Furthermore, unless otherwise limited, the term "polymer" is intended to include all possible geometric configurations of the material. These configurations include, but are not limited to, isotactic, syndiotactic, and atactic symmetries.

[0024] The term "aromatic ring" is used in this disclosure to refer to a conjugated ring system of an organic compound. The aromatic ring may contain only carbon atoms or may contain one or more heteroatoms such as oxygen, nitrogen, or sulfur.

[0025] The term "alkylation" is used in this disclosure to describe a compound that reacts to replace a hydrogen atom or negative charge on a compound with an alkyl group such that the alkyl group becomes covalently attached to the compound.

[0026] 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-chain, cyclic, and bicyclic alkyl groups, and combinations thereof, including both unsubstituted and substituted alkyl groups. Unless otherwise specified, alkyl groups typically contain 1 to 30 carbon atoms. In some embodiments, 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, but are not limited to, methyl, ethyl, n-propyl, n-butyl, n-pentyl, isobutyl, t-butyl, isopropyl, n-octyl, n-heptyl, ethylhexyl, cyclopentyl, cyclohexyl, cycloheptyl, and the like.

[0027] The term "crosslinker" refers to a molecule that can form covalent bonds between separate polymers or between two different regions of the same polymer.

[0028] The term "group" is intended to represent both a specific moiety and a broader class of substituted and unsubstituted structures that include the moiety. Thus, when the term "group" is used to describe a chemical substituent, the described chemical includes the unsubstituted group (e.g., the moiety) and groups having, for example, O, N, Si, or S atoms in the chain (such as alkoxy groups), as well as carbonyl groups or other conventional substitutions. When the term "moiety" is used to describe a chemical compound or substituent, only unsubstituted chemicals are intended to be included. For example, the phrase "alkyl group" is intended to include not only pure open-chain saturated hydrocarbon alkyl substituents such as methyl, ethyl, isopropyl, t-butyl, heptyl, dodecyl, octadecyl, amyl, 2-ethylhexyl, etc., but also alkyl substituents bearing additional substituents known in the art, such as hydroxy, alkoxy, alkylsulfonyl, halogen atoms, cyano, nitro, amino, carboxyl, etc. Thus, "alkyl group" includes ether groups, haloalkyl, nitroalkyl, carboxyalkyl, hydroxyalkyl, sulfoalkyl, etc. On the other hand, the phrase "alkyl moiety" is limited to include only pure open chain saturated hydrocarbon alkyl substituents, such as, for example, methyl, ethyl, isopropyl, t-butyl, heptyl, dodecyl, octadecyl, amyl, 2-ethylhexyl, and the like.

[0029] As used herein, the term "substantially" has the same meaning as "significantly" and can be understood to modify the term that follows it 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 foregoing phrases, the compositions of the present invention contain less than the recited amount of the compound, regardless of whether the compound itself is present in unreacted form or whether it has reacted with one or more other materials.

[0030] As used herein, the term "substantially not" has the same meaning as "not significantly" and can be understood to have the opposite meaning of "substantially," i.e., modifying the term that follows it by 25% or less, 10% or less, 5% or less, or 2% or less.

[0031] The term "about" is used herein in conjunction with numerical values ​​to include normal variations in measurement as would be expected by one of ordinary skill in the art, and is understood to have the same meaning as "approximately," encompassing a typical range of error, such as ±5% of the stated value.

[0032] Terms such as "a," "an," and "the" are not intended to refer to a singular entity only, but include a general class of which a particular example may be used for illustration.

[0033] The terms "a," "an," and "the" are used interchangeably with the term "at least one." The phrases "at least one of" and "including at least one of," followed by a list, refer to any one of the items in the list, and any combination of two or more items in the list.

[0034] As used herein, the term "or" is generally used in its ordinary sense, including "and / or," unless the context clearly dictates otherwise. The term "and / or" refers to one or all of the listed elements or a combination of any two or more of the listed elements.

[0035] The recitation of numerical ranges by endpoints includes all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.; or 10 or less includes 10, 9.4, 7.6, 5, 4.3, 2.9, 1.62, 0.3, etc.). When a range of values ​​is stated "up to" or "at least" a particular value, then all values ​​are included within that range.

[0036] As used herein, the terms "have," "having," "include," "including," "comprise," "comprising," and the like are used in their open-ended sense and generally mean "including, but not limited to." "Consisting essentially of," "consisting of," and the like will be understood to be encompassed by "comprising," and the like. As used herein, "consisting essentially of," with respect to a composition, product, method, and the like, means that the components of the composition, product, method, and the like are limited to the recited components and any other components that do not materially affect the basic and novel characteristics of the composition, product, method, and the like.

[0037] The terms "preferred" and "preferably" refer to embodiments that may offer certain benefits, under particular 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 invention, including the claims.

[0038] Any directions referred to herein, such as "up," "down," "left," "right," "upper," "lower," and other directions and orientations, are provided herein for clarity when referring to the figures and are not intended to limit the actual device or system or the use of the device or system. The devices or systems described herein may be used in several directions and orientations. DETAILED DESCRIPTION OF THE INVENTION

[0039] The present disclosure relates generally to crosslinkable coating systems. The present disclosure further relates to methods of coating articles with crosslinkable coating systems and to articles coated therewith.

[0040] A wide variety of coatings have been used to coat surfaces of articles, structures, packaging, and the like. For example, protective and / or decorative coatings may be applied to wood, wood products, metals, polymers, packaging materials, and the like. With respect to coatings in general, it is desirable to use coating systems that are free of isocyanates and formaldehyde. Additionally, there is a need to find alternative crosslinking chemistries and methodologies to systems that contain isocyanates or formaldehyde. In particular, there is a need to find alternative crosslinking chemistries and methodologies for two-component coating systems that typically contain isocyanates, and one-component coating systems that typically contain formaldehyde.

[0041] The coating system of the present disclosure can be used for many purposes and to coat a variety of materials. The coating system is suitable for use as a coating for wood, wood products, metals, polymers, packaging materials, and the like. The coating system can be used, for example, to coat structural features, architectural elements, articles, containers, packaging, and the like. All such items may be collectively referred to herein as "articles." The present disclosure provides methods of coating articles with the coating composition, and articles coated with the coating composition.

[0042] According to one embodiment, the crosslinkable coating system is based on two reactive compounds, a urea component and an aldehyde, optionally a catalyst, and optionally an amine. The urea component may be unsubstituted or a substituted urea. The urea component reacts with the aldehyde to form a hemiaminal. The hemiaminal may further react with urea or another substituted urea to form an aminal (aminoacetal). The hemiaminal and / or aminal may be used to form oligomers and polymers. The substituted urea may be a mono-N-substituted, N,N-substituted, N,N'-substituted, or N,N,N'-substituted urea. The aldehyde may optionally be in a protected form, such as an acetal or hydrate. In one embodiment, the crosslinkable coating system comprises the reaction product of urea and an aldehyde. In one embodiment, the crosslinkable coating system comprises the reaction product of a mono-N-substituted urea and an aldehyde. In one embodiment, the crosslinkable coating system comprises the reaction product of an N,N-substituted urea and an aldehyde. In one embodiment, the crosslinkable coating system comprises the reaction product of an N,N'-substituted urea and an aldehyde. In one embodiment, the crosslinkable coating system comprises the reaction product of an N,N,N'-substituted urea and an aldehyde. The crosslinkable coating system can also comprise the reaction product of one or more different types of unsubstituted or substituted ureas and one or more different types of aldehydes.

[0043] The combination of a urea component (unsubstituted urea or a substituted urea, e.g., mono-N-substituted urea, N,N-substituted urea, N,N′-substituted urea, or N,N,N′-substituted urea) with an aldehyde provides a crosslinkable coating composition that is free or substantially free of formaldehyde, isocyanates, or both. According to one embodiment, the crosslinkable coating composition is free or substantially free of both formaldehyde and isocyanates. Many prior art one-part compositions include formaldehyde. The crosslinkable coating composition of the present disclosure can be a one-part composition that is free or substantially free of formaldehyde. Many prior art two-part compositions include isocyanates. The crosslinkable coating composition of the present disclosure can be a two-part composition that is free or substantially free of isocyanates.

[0044] The coating composition can be used to prepare polymeric coatings that are free or substantially free of formaldehyde and structural units derived from formaldehyde. The coating composition can be used to prepare polymeric coatings that are free or substantially free of isocyanates and structural units derived from isocyanates. The coating composition can be used to prepare polymeric coatings that are free or substantially free of formaldehyde and structural units derived from formaldehyde, and that are free or substantially free of isocyanates and structural units derived from isocyanates.

[0045] In some embodiments, the coating composition of the present disclosure may be a one-component system or a two-component system. In other words, the coating composition may be a one-part system or a two-part system. A coating composition that is a one-part system refers to a coating system in which the components are premixed, i.e., the reagents are provided as a premixed mixture. Such a premixed mixture does not need to be mixed immediately before applying the coating to an article or surface to be coated with the coating system. In embodiments in which the coating composition is a one-part system, the reactivity of the reagents (unsubstituted or substituted urea, aldehyde, and optional catalyst) can be selected so that the reaction does not occur too early (e.g., before application of the coating composition). For example, the urea component and / or the aldehyde can be selected to have higher or lower reactivity. Furthermore, at least some of the functional groups of the reagents can be protected using protecting groups (e.g., by forming an acetal group or a hydrate on the aldehyde) that prevent reaction from occurring until the protecting groups are removed.

[0046] A coating composition that is a two-part coating system refers to a coating system composition that is not in a premixed form. It refers to a coating system that is comprised of two mixtures of the coating system reagents. The reagents in the two mixtures are substantially non-reactive until the two mixtures (or "two parts") are combined together. Combining the two "parts" of a two-part coating system allows the reagents to react to form a coating.

[0047] Urea component According to one embodiment, the crosslinkable coating system of the present disclosure comprises the reaction product of a urea component and an aldehyde. The urea component can be unsubstituted or substituted. The substituted urea can be mono-N-substituted, N,N-substituted, N,N'-substituted, or N,N,N'-substituted urea.

[0048] According to one embodiment, the urea component is represented by formula (I):

[0049] [ka] In the formula, R 1 , R 2 , R 3 , and R 4 are independently H or a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R 1 , R 2 , R 3 , and R 4 R is independently H or an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group. 1 , R 2 , R 3 , and R 4 At least one of R is H. 1 , R 2 , R 3 , and R 4 R may independently be straight chain, branched chain, or cyclic and may contain zero, one, or more double bonds. 1 , R 2 , R 3 , and R 4 Any two of R may be connected to each other to form a cyclic group. 1 , R 2 , R 3 , and R 4 may independently contain any suitable number of carbon atoms. In some embodiments, R 1 , R 2 , R 3 , and R 4 may independently be oligomeric or polymeric.

[0050] According to one embodiment, the urea component is urea and is represented by the following formula (IA):

[0051] [ka] That is, R 1 , R 2 , R 3 , and R 4 Each of is H.

[0052] According to one embodiment, the urea component is a mono-substituted N-substituted urea, referred to herein as a mono-N-substituted urea. The mono-N-substituted urea may be represented by formula (IB):

[0053] [ka] In the formula, R 1 is a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R 1 R is an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group. 1 R may be straight chain, branched chain, or cyclic and may contain zero, one, or more double bonds. 1 may contain any suitable number of carbon atoms. In some embodiments, R 1 may be an oligomer or a polymer.

[0054] In some embodiments, the mono-N-substituted urea can be obtained by any technique known in the art. For example, the mono-N-substituted urea can be obtained by oxidation of a primary amine with potassium cyanate,

[0055] [ka] or may be obtained by condensation of a primary amine with urea.

[0056] [ka]

[0057] In some embodiments, mono-N-substituted ureas can be obtained by condensation of a primary amine with methyl carbamate.

[0058] [ka]

[0059] Some non-limiting examples of amino- or hydroxy-functionalized mono-N-substituted ureas include 2-hydroxyethyl urea, 2-aminoethyl urea, and 1,1'-(iminodi-2,1-ethanediyl)diurea. Various amino- or hydroxy-functionalized mono-N-substituted ureas can be used to generate monomers. Some non-limiting examples of such monomers utilized in radical polymerization include the following:

[0060] [ka]

[0061] Some relevant non-limiting examples of monomers generated from amino or hydroxy functionalized mono-N-substituted ureas and utilized in polycondensation include the following:

[0062] [ka] 2-Aminoethylurea and 1,1'-(iminodi-2,1-ethanediyl)diurea can also react with polyunsaturated molecules such as poly(meth)acrylates via aza-Michael addition to form polyureas.

[0063] According to one embodiment, the urea component is an N,N-substituted urea represented by the following formula (IC):

[0064] [ka] In the formula, R 1 and R 2 are independently carbon-containing groups optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or combinations thereof, and preferably R 1 and R 2 R is independently an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group. 1 and R 2 R may independently be straight chain, branched chain, or cyclic and may contain zero, one, or more double bonds. 1 and R 2 may independently contain any suitable number of carbon atoms. In some embodiments, R 1 and R 2 may independently be oligomeric or polymeric.

[0065] N,N-substituted ureas can be obtained, for example, by condensation of secondary amines with urea.

[0066] [ka]

[0067] Some relevant non-limiting examples of hydroxy-functionalized secondary amines used to generate N,N-substituted ureas include (2-hydroxyethyl)methylamine and diethanolamine, which can be utilized to generate 1,1-bis(2-hydroxyethyl)urea for polycondensation.

[0068] [ka] (2-Hydroxyethyl)methylamine can be utilized to generate molecules of the following structure for radical polymerization:

[0069] [ka]

[0070] According to one embodiment, the urea component is an N,N'-substituted urea represented by the following formula (ID):

[0071] [ka] In the formula, R 1 and R 3 are independently carbon-containing groups optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or combinations thereof, and preferably R 1 and R 3 R is independently an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group. 1 and R 3 R may independently be straight chain, branched chain, or cyclic and may contain zero, one, or more double bonds. 1 and R 3 may independently contain any suitable number of carbon atoms. In some embodiments, R 1 and R 3 may independently be oligomeric or polymeric.

[0072] In some embodiments, N,N'-substituted ureas can be obtained, for example, by condensation of two primary amines with urea.

[0073] [ka]

[0074] A relevant non-limiting example of an N,N'-substituted urea is 1,3-bis(2-hydroxyethyl)urea, which can be produced from urea and ethanolamine and used in polycondensation.

[0075] [ka]

[0076] According to one embodiment, the urea component is an N,N,N'-substituted urea represented by the following formula (IE):

[0077] [ka] In the formula, R 1 , R 2 , and R 3 are independently carbon-containing groups optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or combinations thereof, and preferably R 1 , R 2 , and R 3 R is independently an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group. 1 , R 2 , and R 3 R may independently be straight chain, branched chain, or cyclic and may contain zero, one, or more double bonds. 1 , R 2 , and R 3 may independently contain any suitable number of carbon atoms. In some embodiments, R 1 , R 2 , and R 3 may independently be oligomeric or polymeric.

[0078] Exemplary cyclic urea moieties include those of the formula:

[0079] [ka] In the formula, R 1 is H or a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R 1 R is independently an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group. 1 R may be straight chain, branched chain, or cyclic and may contain zero, one, or more double bonds. 1 may contain any suitable number of carbon atoms. In some embodiments, R 1 may be an oligomer or polymer, wherein n is greater than 1, preferably n is 2, 3, 4, 5, or 6, and more preferably n is 2 or 3.

[0080] Some non-limiting relevant examples of cyclic N,N,N'-substituted ureas are 1-(2-hydroxyethyl)-2-imidazolidinone and 1-(2-aminoethyl)-2-imidazolidinone. In some embodiments, such cyclic N,N,N'-substituted ureas can be used, for example, to generate monomers for radical polymerization.

[0081] [ka]

[0082] In some embodiments, 1-(2-aminoethyl)-2-imidazolidinone can react with polyunsaturated molecules, such as poly(meth)acrylates, via aza-Michael addition to produce polyureas.

[0083] Specific non-limiting relevant examples of the urea component include urea, 2-imidazolidone, glycoluril, 2-hydroxyethyl urea, methacryloxyethyl ethylene urea, biuret, allophanate, and methacrylamidoethyl ethylene urea.

[0084] [ka]

[0085] In some embodiments, Formula (I) is not a polyether. In some embodiments, Formula (I) does not comprise a polyether.

[0086] In some embodiments, the urea compound is a di-N,N'-substituted urea represented by the following formula (IG):

[0087] [ka] In the formula, each R 1 and R 2 are independently carbon-containing groups optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or combinations thereof, and preferably each R 1 and R 2 is independently an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, alkylamine, or urea group. 1 and R 2 may independently be straight-chained, branched-chained, or cyclic and may contain zero, one, or more double bonds. 1 and R 2 may independently contain any suitable number of carbon atoms. In some embodiments, each R 1 and R 2 may independently be oligomeric or polymeric.

[0088] The urea component may be a triurea or polyurea similar to the diurea of ​​formula (IG): The urea component may further include branched chain urea functional groups, such as in the structure of formula (IF):

[0089] [ka] wherein m is 2, 3, or 4.

[0090] The amines utilized in the synthesis of the urea component may include diamines (e.g., N-tetramethyl-1,6-hexanediamine, 2-methylpentane-1,5-diamine, etc.), triamines (e.g., tris(2-aminoethyl)amine), or oligomeric amines (e.g., polyethyleneimine in linear, branched, or dendrimeric form).

[0091] The urea component may be a diurea or triurea obtained by transurethanization of methyl carbamate with a diamine or triamine.

[0092] [ka]

[0093] In some embodiments, the urea component may be an acrylic resin obtained by free radical polymerization of a monomer containing a substituted urea group. Non-limiting examples of such acrylic resins include methacrylate N-hydroxyethylurea obtained by transesterification of N-hydroxyethylurea with methyl methacrylate, which may be obtained by oxidation of ethanolamine with potassium cyanate. Non-limiting examples of such monomers include N,N,N'-substituted cyclic urea methacryloxyethylethyleneurea (formula (IFa)), commercially available as UMA 25% (available from BASF, Florham Park, NJ), WAM 250 (available from Solvay Chemicals, Inc., Alorton, IL), or MEEU-50W or MEEU-25M (available from Evonik, Piscataway, NJ).

[0094] [ka]

[0095] The urea component may be a polyester resin obtained by esterification or transesterification of a monomer containing a substituted urea group. Non-limiting examples of such monomers include N,N-substituted urea-containing diols, which can be obtained by the deamination reaction between urea and diethanolamine.

[0096] [ka]

[0097] aldehyde According to one embodiment, the crosslinkable coating system of the present disclosure comprises the reaction product of a urea component and an aldehyde. The aldehyde can be a monoaldehyde, dialdehyde, trialdehyde, or polyaldehyde. The aldehyde can be an oligomer or polymer. The aldehyde can optionally be in a protected form, such as an acetal or hydrate, prior to reaction. In some embodiments, the aldehyde is a liquid at room temperature (about 20° C. to 25° C.). The aldehyde can also have low toxicity and an acceptable odor.

[0098] In some embodiments, the aldehyde is a monoaldehyde. Some non-limiting relevant examples of suitable aldehydes include heptanal, octanal, cyclohexanecarboxaldehyde, benzaldehyde, furfural, vanillin, hydroxymethylfurfural ("HMF"), pivalaldehyde, hydroxypivalaldehyde, and aliphatic aldehydes obtained by oxidative cleavage of double bonds. In some cases, the aldehyde may be bio-based, obtained from a non-petroleum source.

[0099] The aldehyde may be represented by the following formula (II):

[0100] [ka] In the formula, R 5 is a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R 5 is an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group. 5 R may be straight chain, branched chain, or cyclic and may contain zero, one, or more double bonds. 5 may contain any suitable number of carbon atoms. In some embodiments, R5 may be an oligomer or a polymer.

[0101] In some embodiments, the aldehyde in the crosslinkable coating system of the present disclosure is a polyaldehyde selected from the group consisting of terephthalaldehyde, glutaraldehyde, glyoxal, dimethoxyacetaldehyde, methylglyoxal, cyclohexanedicarbaldehyde, malondialdehyde bis(dimethyl acetal), 5,5′-(oxy-bis(methylene))bis-2-furfural, bis(dimethyl acetal) of imidazolidone, tetra-dimethyl acetal of glycoluril, bis(dimethyl acetal) of polyglycidyl ether, tri(aminoethyl dimethyl acetal) of itaconic acid, tri(aminoethyl dimethyl acetal) of TMPEOTA, and poly(dimethyl acetal) of polycyclocarbonate.

[0102] In some embodiments, the aldehyde is in a protected form as an acetal. The acetal can be obtained by reacting an aldehyde with an alcohol and can be represented by the following formula (IIA):

[0103] [ka] In the formula, R 5 is a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R 5 is an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group. 5 R may be straight chain, branched chain, or cyclic and may contain zero, one, or more double bonds. 5may contain any suitable number of carbon atoms. In some embodiments, R 5 may be an oligomer or a polymer. 6 and R 7 are independently carbon-containing groups optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or combinations thereof, and preferably each R 6 and R 7 is independently an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, alkylamine, or urea group. 6 and R 7 may independently be straight-chained, branched-chained, or cyclic and may contain zero, one, or more double bonds. 6 and R 7 may independently contain any suitable number of carbon atoms. In some embodiments, each R 6 and R 7 may independently be an oligomer or a polymer. In a preferred embodiment, R 6 and R 7 are independently carbon-containing groups having 1 to 4 carbon atoms.

[0104] In some preferred embodiments, R on the acetal of formula (IIA) 6 and R 7 The group is R 6 =R 7 In some embodiments, R 6 and R 7 can be linked to form a cyclic acetal.

[0105] [ka]

[0106] In some embodiments, the aldehyde is in a protected form as a hydrate, which can be obtained by the reaction of water with the aldehyde and can be represented by the formula:

[0107] [ka] In the formula, R 5 is a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R 5 is an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group. 5 R may be straight chain, branched chain, or cyclic and may contain zero, one, or more double bonds. 5 may contain any suitable number of carbon atoms. In some embodiments, R 5 may be an oligomer or a polymer.

[0108] In the following, the term aldehyde describes the aldehyde or hydrate or acetal.

[0109] In some embodiments, the aldehyde is a polyaldehyde, such as terephthalaldehyde, glutaraldehyde, glyoxal, dimethoxyacetaldehyde, methylglyoxal, cyclohexanedicarbaldehyde, and malondialdehyde bis(dimethyl acetal), 5,5'-(oxy-bis(methylene))bis-2-furfural (Example 22), bis(dimethyl acetal) of imidazolidone (Example 14), tetra-dimethyl acetal of glycoluril, bis(dimethyl acetal) of polyglycidyl ether (Example 12), tri(aminoethyl dimethyl acetal) of itaconic acid (Example 13), tri(aminoethyl dimethyl acetal) of TMPEOTA (Example 10), or poly(dimethyl acetal) of polycyclocarbonate (Example 15).

[0110] In some embodiments, the aldehyde is oligomeric or polymeric. Oligomeric or polymeric aldehydes can contain multiple aldehyde functional groups. For example, the aldehyde can be a dialdehyde obtained by condensation of a hydroxyaldehyde, such as 5,5'-[oxy-bis(methylene)]di(2-furaldehyde). The dialdehyde can be formed by crotonization with an enolizable ketone, such as cyclohexanone. In one example, the dialdehyde is formed from HMF and cyclohexanone. The ketone can be used in an HMF / cyclohexanone ratio greater than 1. The aldehyde can also be a dialdehyde obtained by coupling two hydroxyaldehydes with a dicarbamate.

[0111] In some embodiments, the aldehyde is an acrylic (co)polymer that can be obtained by free radical polymerization of a monomer mixture containing an aldehyde-functional monomer. Such an aldehyde-functional monomer can be obtained in various ways. For example, such an aldehyde-functional monomer can be based on acrolein, acrolein diethyl acetal, N-methacrylamidoacetaldehyde dimethyl acetal (Example 9), or 5-(hydroxymethyl)furfural methacrylate (HMF methacrylate, Example 22), or 4-methacryloyloxy-3-methoxybenzaldehyde (vanillin methacrylate). Alternatively, the reaction product of aminoacetaldehyde dimethyl acetal (or (methylamino)acetaldehyde dimethyl acetal) with glycidyl ether methacrylate (GMA), glycerol carbonate methacrylate (GCMA), 4-(chloromethyl)styrene (CMS), or 3-acryloyloxy-2-hydroxypropyl methacrylate, Where R = H or CH3

[0112] [ka]

[0113] Or it may be based on the reaction product of pivalaldehyde with methacrylic anhydride or 4-(chloromethyl)styrene.

[0114] [ka]

[0115] In some embodiments, the aldehyde may be a polyester resin obtained by esterification or transesterification of a monomer mixture containing an aldehyde-functional monomer. Such aldehyde-functional monomers can be obtained by various methods known in the art. For example, such aldehyde-functional monomers can be based on itaconic acid reacted with aminoacetaldehyde dimethyl acetal or (methylamino)acetaldehyde dimethyl acetal via aza-Michael addition.

[0116] [ka]

[0117] Coatings According to one embodiment, the coating system of the present disclosure includes a urea component according to formula (I) above (e.g., formulas (IA)-(IF)) and an aldehyde according to formula (II) above. In some embodiments, the coating system of the present disclosure may also include a solvent. In some embodiments, the urea component and aldehyde may be present in a molar ratio of 0.5-2.5 moles, 0.5-2.0 moles, 1.0-2.0 moles, or 1.5-2.5 moles of urea component per mole of aldehyde. According to one embodiment, the coating system is crosslinkable.

[0118] According to one embodiment, the crosslinkable coating system is provided as a one-part or two-part composition. The crosslinkable coating system may be a dry powder composition or a solvent-based composition. A dry powder composition is a composition in which each component is in powder form. Dry powder components can be blended together and applied in powder form. Components of a solvent-based system can be either liquid or powder and mixed in a solvent and applied in liquid form.

[0119] In embodiments where the composition is solvent-based, the coating composition comprises at least 1 wt%, at least 2 wt%, at least 5 wt%, at least 10 wt%, at least 20 wt%, at least 30 wt%, or at least 40 wt% of the combined urea component and aldehyde, based on the total resin solids in the coating composition. The coating composition can comprise at most 60 wt%, at most 50 wt%, at most 40 wt%, at most 30 wt%, at most 20 wt%, or at most 10 wt% of the combined urea component and aldehyde, based on the total resin solids in the coating composition.

[0120] Solvent-based compositions can include water or organic solvents, or combinations thereof. Exemplary solvents include ketones, acetates, aromatics, alcohols, ethers, and combinations thereof (including aqueous mixtures).

[0121] The coating composition can also optionally be rheologically modified for different coating applications. For example, the coating composition can be diluted with an additional amount of solvent to reduce the total solids content in the coating composition. Alternatively, a portion of the solvent can be removed (e.g., evaporated) to increase the total solids content in the coating composition. The final total solids content in the coating composition can vary depending on the particular coating application used, the particular coating application, the desired coating thickness, etc.

[0122] In some embodiments, the coating composition has a total solids weight of greater than about 5%, more preferably greater than about 10%, and even more preferably greater than about 15%, based on the total weight of the coating composition. In liquid embodiments, the coating composition also preferably has a total solids weight of less than about 80%, more preferably less than about 60%, and even more preferably less than about 50%, based on the total weight of the coating composition. The solvent (e.g., aqueous or organic solvent) may comprise the remainder of the weight of the coating composition.

[0123] In one embodiment, the coating composition is a powder coating composition. The powder coating composition may include a base powder formed at least in part from the polymer of the present disclosure. The coating composition may include one or more optional ingredients within the particles of the base powder and / or within separate particles. Such optional ingredients may include, for example, crosslinkers, cure accelerators, color pigments, fillers, flow additives, and the like.

[0124] The coating composition may optionally include one or more additional resins in addition to the reaction product of the urea component and the aldehyde, for example, to modify the properties of the resulting coating.

[0125] The coating composition may optionally contain one or more additives. When used, the additives preferably improve and preferably do not adversely affect the coating composition or the cured coating formed therefrom. For example, additives may be included in the coating composition to improve the aesthetics of the composition, to facilitate the manufacture, processing, handling, and application of the composition, or to further improve certain functional properties of the coating composition or the cured coating obtained therefrom. Such optional additives include, for example, catalysts, dyes, pigments, toners, extenders, fillers, lubricants, corrosion inhibitors, flow control agents, thixotropic agents, dispersants, antioxidants, adhesion promoters, light stabilizers, co-resins, and mixtures thereof. Each optional additive is preferably included in an amount sufficient to fulfill its intended purpose, but not in an amount that adversely affects the coating composition or the cured coating obtained therefrom.

[0126] In some embodiments, the coating composition comprises one or more catalysts. In some embodiments, the coating composition comprises an acid catalyst. Suitable acid catalysts are acids with a pKa of less than 7 or less than 6. Acid functional groups on the polymer can also act as catalysts.

[0127] Examples of acid catalysts include Lewis acids (e.g., boron trifluoride etherate) and protic acids (i.e., Bronsted acids). 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 a carboxylic acid, a phosphonic acid, or a sulfonic acid. Exemplary carboxylic acids suitable for use as the acid catalyst include acetic acid, trifluoroacetic acid, and propionic acid. An exemplary phosphonic acid is methylphosphonic acid. Exemplary sulfonic acids include methanesulfonic acid, benzenesulfonic acid, camphorsulfonic acid, para-toluenesulfonic acid, and dodecylbenzenesulfonic acid (DBSA). Examples of suitable Lewis acid catalysts are aluminum trichloride (AlCl), benzyltriethylammonium chloride (TEBAC), Cu(OSCF), (CH)BrSBr, FeCl (e.g., FeCl6H0), HBF, BF0(CHCH), TiCl, SnCl, CrCl, NiCl, ZnBr, and Pd(OC(O)CH). The acid catalyst may be unsupported (without a solid support) or supported, for example, covalently bound to a solid support.

[0128] Alternatively, amines such as DMEA, triethylamine, other tertiary amines, and ammonia can be used to retard reactivity.

[0129] Another useful optional additive is a lubricant (e.g., wax), which facilitates the manufacture of metal closures and other engineered coated articles by imparting lubricity to the coated metal substrate. Preferred lubricants include, for example, carnauba wax and polyethylene-type lubricants. When used, the lubricant is preferably present in the coating composition in an amount of at least about 0.1 wt. %, preferably no more than about 2 wt. %, and even more preferably no more than about 1 wt. %, based on the total weight of solids in the coating composition.

[0130] Another useful optional additive is an organosilicon material, such as a siloxane-based material or a polysilicon-based material. Representative examples of suitable such materials are disclosed in International Patent Application Publication Nos. WO2014 / 089410(A1) and WO2014 / 186285(A1).

[0131] Another useful optional ingredient is a pigment, such as titanium dioxide, which, when used, is present in the coating composition in an amount of about 70% by weight or less, more preferably about 50% by weight or less, and even more preferably about 40% by weight or less, based on the total weight of solids in the coating composition.

[0132] The urea component and aldehyde react to form a hemiaminal, which can further react to form an aminal (aminoacetal), which can be used to form oligomers and polymers. The reaction between a substituted urea and an aldehyde can be represented by the following two-part reaction:

[0133] [ka]

[0134] The reaction product of the mono-N-substituted urea and the aldehyde can be represented by the following formula (III):

[0135] [ka] In the formula, R 1 is the same as formula (IB), and R 5 is the same as formula (II).

[0136] Further reaction products of mono-N-substituted ureas with aldehydes can be represented by formula (IV):

[0137] [ka] In the formula, R 1 is the same as formula (IB), and R 5is the same as formula (II).

[0138] Similar reaction products can be formed between N,N-substituted, N,N'-substituted, and N,N,N'-substituted ureas and aldehydes.

[0139] The reaction product (forming the coating composition) can be applied to a surface and cured to induce crosslinking. The resulting coating can be a poly(hemiaminal-urea) functionalized network (when using Formula III or a similar reaction product) or a poly(aminal-urea) functionalized network (when using Formula IV or a similar reaction product). According to one embodiment, the coating composition is free or substantially free of isocyanates. According to one embodiment, the coating composition is free or substantially free of formaldehyde. According to one embodiment, the coating composition is free or substantially free of both isocyanates and formaldehyde.

[0140] Curing / crosslinking After being applied to a surface, the coating composition may be cured to cause crosslinking of the composition.

[0141] The coating composition may be cured at a temperature of 150° C. or less, 125° C. or less, 110° C. or less, 100° C. or less, 90° C. or less, 80° C. or less, 70° C. or less, 60° C. or less, 50° C. or less, 40° C. or less, 30° C. or less, or 25° C. The coating composition may be cured at a temperature ranging from 0° C. to 150° C., 10° C. to 125° C., 10° C. to 90° C., 10° C. to 50° C., 10° C. to 40° C., 10° C. to 30° C., or 10° C. to 25° C. In some embodiments, the coating composition is curable at room temperature.

[0142] In some embodiments, it may be desirable for the coating composition to be non-reactive at low temperatures, such as room temperature. The components of the coating composition can be selected to achieve the desired curing and crosslinking conditions. For example, the urea component can be selected based on Table 1 below to achieve the reactive conditions.

[0143] [Table 1]

[0144] Similarly, the aldehyde may be selected to be more or less reactive based on Table 2 below.

[0145] [Table 2]

[0146] The additives used in the coating composition can also be selected to achieve the desired reaction conditions. For example, acid catalysts or polymer chains bearing carboxylic acid functional groups can be used to improve the reactivity of the crosslinking reaction. Amines (such as dimethylethanolamine or DMEA) can be used to slow down the reactivity.

[0147] According to embodiments, urea-based crosslinking systems are at least as reactive as carbamate-based crosslinking systems.

[0148] Coating method and coated article The present disclosure provides methods for coating articles with coating compositions, and articles coated with the coating compositions. The coating compositions of the present disclosure can be used for many purposes and to coat a variety of materials. The coating compositions are suitable for use as coatings for wood, wood products, metals, polymers, packaging materials, and the like.

[0149] A coating method according to one embodiment includes applying a coating composition to a surface of an article, the coating composition including a urea component according to formula (I) above (e.g., formulas (IA) to (IF)), and an aldehyde according to formula (II) above.

[0150] In some embodiments, a packaging article has a coating according to an embodiment of the present disclosure disposed on a surface of the packaging article. In one embodiment, the packaging article is a container, such as a food or beverage container, or a portion thereof (e.g., a twist-off closure, a beverage can end, a food can end, etc.), and at least a portion of the interior surface of the container is coated with a coating composition. The coating may include a reaction product of a urea component according to formula (I) above (e.g., formulas (IA)-(IG)) with an aldehyde according to formula (II) above. The coating may include a network formed from a hemiaminal of formula (III) above. The coating may include a network formed from an aminal of formula (IV) above. The coating may be a crosslinked coating resulting from crosslinking of a hemiaminal of formula (III) or an aminal of formula (IV).

[0151] Illustrative Embodiments Embodiment 1 is urea component, Aldehydes containing two or more carbon atoms, and a coating system comprising a solvent.

[0152] Embodiment 2 is the coating system of embodiment 1, wherein the urea component is present in a molar ratio of 0.5 to 2.5 moles per mole of aldehyde.

[0153] In a third embodiment, the urea component is represented by formula (I):

[0154] [ka] In the formula, R 1 , R 2 , R 3 , and R 4 are independently H or a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R 1 , R 2 , R 3 , and R 4is independently H or an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group; R 1 , R 2 , R 3 , and R 4 at least one of is H; R 1 , R 2 , R 3 , and R 4 any two of which may be connected to each other to form a cyclic group.

[0155] In a fourth embodiment, the urea component is represented by the following formula (IA):

[0156] [ka] The coating system according to any one of the first to third embodiments.

[0157] In a fifth embodiment, the urea component comprises a mono-N-substituted urea having the formula (IB):

[0158] [ka] In the formula, R 1 is a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R 1 The coating system of any one of embodiments 1-3, wherein R is an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group. 1R may be straight chain, branched chain, or cyclic and may contain zero, one, or more double bonds. 1 may contain any suitable number of carbon atoms. In some embodiments, R 1 may be an oligomer or a polymer.

[0159] In a sixth embodiment, the urea component comprises an N,N-substituted urea having the formula (IC):

[0160] [ka] In the formula, R 1 and R 2 are independently carbon-containing groups optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or combinations thereof, and preferably R 1 and R 2 The coating system of any one of embodiments 1-3, wherein R is independently an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group. 1 and R 2 R may independently be straight chain, branched chain, or cyclic and may contain zero, one, or more double bonds. 1 and R 2 may independently contain any suitable number of carbon atoms. In some embodiments, R 1 and R 2 may independently be oligomeric or polymeric.

[0161] In embodiment 7, the urea component comprises an N,N'-substituted urea having formula (ID):

[0162] [ka] In the formula, R 1 and R 3are independently carbon-containing groups optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or combinations thereof, and preferably R 1 and R 3 The coating system of any one of embodiments 1-3, wherein R is independently an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group. 1 and R 3 R may independently be straight chain, branched chain, or cyclic and may contain zero, one, or more double bonds. 1 and R 3 may independently contain any suitable number of carbon atoms. In some embodiments, R 1 and R 3 may independently be oligomeric or polymeric.

[0163] In an eighth embodiment, the urea component comprises an N,N,N'-substituted urea having the formula (IE):

[0164] [ka] In the formula, R 1 , R 2 , and R 3 are independently carbon-containing groups optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or combinations thereof, and preferably R 1 , R 2 , and R 3 The coating system of any one of embodiments 1-3, wherein R is independently an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group. 1 , R 2, and R 3 R may independently be straight chain, branched chain, or cyclic and may contain zero, one, or more double bonds. 1 , R 2 , and R 3 may independently contain any suitable number of carbon atoms. In some embodiments, R 1 , R 2 , and R 3 may independently be oligomeric or polymeric.

[0165] Embodiment 9 is the coating system of any one of embodiments 1-3, wherein the urea component comprises 2-imidazolidone, glycoluril, 2-hydroxyethyl urea, methacryloxyethyl ethylene urea, biuret, methacrylamidoethyl ethylene urea, or a combination thereof.

[0166] In a tenth embodiment, the urea component comprises a di-N,N'-substituted urea having formula (IF):

[0167] [ka] In the formula, R 1 is H or a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R 1 The coating system of any one of embodiments 1-3, wherein R is independently an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group. 1 R may be straight chain, branched chain, or cyclic and may contain zero, one, or more double bonds. 1 may contain any suitable number of carbon atoms. In some embodiments, R 1 may be an oligomer or polymer, wherein n is greater than 1, preferably n is 2, 3, 4, 5, or 6, and more preferably n is 2 or 3.

[0168] Embodiment 11 is an embodiment wherein the urea component comprises a di-N,N'-substituted urea represented by formula (IG):

[0169] [ka] In the formula, each R 1 and R 2 are independently carbon-containing groups optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or combinations thereof, and preferably each R 1 and R 2 is independently an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or alkylamine group. 1 and R 2 may independently be straight-chained, branched-chained, or cyclic and may contain zero, one, or more double bonds. 1 and R 2 may independently contain any suitable number of carbon atoms. In some embodiments, each R 1 and R 2 may independently be oligomeric or polymeric.

[0170] Embodiment 12 is a coating system of any one of embodiments 1-3 or 11, wherein the urea component is part of an oligomer containing multiple unsubstituted or substituted urea functional groups.

[0171] Embodiment 13 is directed to an aldehyde that can be represented by formula (II) or (IIA):

[0172] [ka] In the formula, R 5 is a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R 5 13. The coating system of any one of embodiments 1-12, wherein R is an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group, and optionally the aldehyde is in a protected form, including an acetal or hydrate. The aldehyde may be a monoaldehyde. The aldehyde may be a polyaldehyde. The aldehyde may be an oligomer. Also, each R 6 and R 7 are independently carbon-containing groups optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or combinations thereof, and preferably each R 6 and R 7 is independently an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, alkylamine, or urea group. 6 and R 7 may independently be straight-chained, branched-chained, or cyclic and may contain zero, one, or more double bonds. 6 and R 7 may independently contain any suitable number of carbon atoms. In some embodiments, each R 6 and R 7 may independently be an oligomer or a polymer. In a preferred embodiment, R 6 and R 7 are independently a carbon-containing group having 1 to 4 carbon atoms. In some preferred embodiments, R on the acetal of formula (IIA) 6 and R 7 The group is R 6 =R7 In some embodiments, R 6 and R 7 may combine to form a cyclic acetal. In some embodiments, the aldehyde in the crosslinkable coating system of the present disclosure is a polyaldehyde. In some embodiments, the polyaldehyde in the crosslinkable coating system of the present disclosure is selected from the group consisting of terephthalaldehyde, glutaraldehyde, glyoxal, dimethoxyacetaldehyde, methylglyoxal, cyclohexanedicarbaldehyde, malondialdehyde bis(dimethyl acetal), 5,5'-(oxy-bis(methylene))bis-2-furfural, bis(dimethyl acetal) of imidazolidone, tetra-dimethyl acetal of glycoluril, bis(dimethyl acetal) of polyglycidyl ether, tri(aminoethyl dimethyl acetal) of itaconic acid, tri(aminoethyl dimethyl acetal) of TMPEOTA, and poly(dimethyl acetal) of polycyclocarbonate.

[0173] Embodiment 14 is the coating system of any one of embodiments 1-13, wherein the aldehyde comprises a monoaldehyde.

[0174] Embodiment 15 is the coating system of any one of embodiments 1-13, wherein the aldehyde comprises a polyaldehyde.

[0175] Embodiment 16 is the coating system of any one of embodiments 1-15, wherein the aldehyde is an oligomer.

[0176] Embodiment 17 is directed to a method for preparing a urea compound comprising the steps of:

[0177] [ka] In the formula, R 1 is a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R 1is an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group; R 5 is the same as formula (II),

[0178] Embodiment 18 is directed to a method for preparing a urea compound, comprising:

[0179] [ka] In the formula, R 1 is a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R 1 is an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group; R 5 is the same as formula (II),

[0180] Embodiment 19 is the coating system of any one of embodiments 1-18, wherein the coating system is free or substantially free of formaldehyde.

[0181] Embodiment 20 is the coating system of any one of embodiments 1-19, wherein the coating system is free or substantially free of isocyanates.

[0182] Embodiment 21 is the coating system of any one of embodiments 1-20, wherein the coating system is curable at a temperature of 150° C. or less, 125° C. or less, 110° C. or less, 100° C. or less, 90° C. or less, 80° C. or less, 70° C. or less, 60° C. or less, 50° C. or less, 40° C. or less, 30° C. or less, or 25° C. The coating composition may be cured at a temperature ranging from 0° C. to 150° C., 10° C. to 125° C., 10° C. to 90° C., 10° C. to 50° C., 10° C. to 40° C., 10° C. to 30° C., or 10° C. to 25° C. In some embodiments, the coating composition is curable at room temperature.

[0183] Embodiment 22 is the coating system of any one of embodiments 1-21, wherein the coating system comprises at least 1 wt%, at least 2 wt%, at least 5 wt%, at least 10 wt%, at least 20 wt%, at least 30 wt%, or at least 40 wt% of the combined urea component and aldehyde, based on the total resin solids in the coating composition. The coating system can comprise at most 60 wt%, at most 50 wt%, at most 40 wt%, at most 30 wt%, at most 20 wt%, or at most 10 wt% of the combined urea component and aldehyde, based on the total resin solids in the coating system.

[0184] Embodiment 23 is the coating system of any one of embodiments 1-22, wherein the coating system comprises an acid catalyst, and optionally the acid catalyst has a pKa of less than 7 or less than 6.

[0185] Embodiment 24 is the coating system of embodiment 23, wherein the acid catalyst comprises phosphoric acid, sulfuric acid, acetic acid, trifluoroacetic acid, propionic acid, methylphosphonic acid, methanesulfonic acid, benzenesulfonic acid, camphorsulfonic acid, paratoluenesulfonic acid (PTSA), dodecylbenzenesulfonic acid (DBSA), aluminum trichloride (AlCl), benzyltriethylammonium chloride (TEBAC), Cu(OSCF), (CH)BrSBr, FeCl, HBF, BF0(CHCH), TiCl, SnCl, CrCl, NiCl, ZnBrPd(OC(O)CH), or a combination thereof.

[0186] Embodiment 25 is a coating system comprising the reaction product of a urea component and an aldehyde containing two or more carbon atoms.

[0187] Embodiment 26 is the method for preparing a crosslinked product of formula (III):

[0188] [ka] In the formula, R 1 is a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R 1 is an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group; R 5 is the same as formula (II).

[0189] Embodiment 27 is an embodiment wherein the reaction product is a crosslinked product of formula (IV):

[0190] [ka] In the formula, R 1 is a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R 1 is an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group; R 5 is the same as formula (II).

[0191] Embodiment 28 is the coating system of any one of embodiments 25-27, wherein the coating system is in powder form.

[0192] Embodiment 29 is the coating system of any one of embodiments 1-27, wherein the coating system comprises an organic solvent, water, or both.

[0193] Embodiment 30 is the coating system of any one of embodiments 25-29, wherein the coating system is free or substantially free of formaldehyde or structural units derived from formaldehyde.

[0194] Embodiment 31 is the coating system of any one of embodiments 25-31, wherein the coating system is free or substantially free of isocyanates or structural units derived from isocyanates.

[0195] Embodiment 32 is an article coated with the coating system of any one of embodiments 1-31. [Example]

[0196] Example 1 Synthesis of bis-ureas from diamines and methyl carbamates.

[0197] [ka] 5 g of 2-methylpentane-1,5-diamine and 32.3 g of methyl carbamate were placed in a reaction vessel equipped with a Dean-Stark distillation column. Dibutyltin dilaurate ("DBTDL") was added to the reaction vessel, and the reaction mixture was heated to 120°C for 6-10 hours. The resulting methanol formed during the reaction was removed by distillation. The reaction procedure yielded the product in 42% yield. 1 The resulting spectrum was analyzed by H-NMR, and is shown in Figure 1.

[0198] Example 2 Synthesis of bis-urea from dodecanediamine and urea

[0199] [ka] 30 g (0.5 mol) of urea was added to 100 g of ethanol. The reaction mixture was stirred at 80°C until the urea was completely dissolved. Next, 10 g (0.05 mol) of dodecanediamine was added to the reaction vessel, and the reaction mixture was continued to be stirred at 80°C for 10 hours. The reaction mixture was then cooled, and the bis-urea product was precipitated in ethanol. The precipitate was filtered and rinsed with cold ethanol. The product was then dried at room temperature. The reaction and purification yielded the product in 12 g (84%).

[0200] Example 3 Synthesis of bis-urea from diethylenetriamine (DETA) and urea

[0201] [ka] 30 g (0.5 mol) of urea was added to 100 g of ethanol. The reaction mixture was stirred at 80°C until the urea was completely dissolved. Next, 5.15 g (0.05 mol) of diethylenetriamine was added to the reaction vessel, and the reaction mixture was continued to be stirred at 80°C for 10 hours. The reaction mixture was then cooled, and the diurea product was precipitated in ethanol. The precipitate was filtered and rinsed with cold ethanol. The product was then dried at room temperature. The reaction and purification yielded the product in a yield of 6 g (63%). 1 The resulting product was analyzed by H-NMR. 1 The H-NMR spectrum is shown in Figure 2.

[0202] Example 4 Synthesis of hydroxylethylurea methacrylate (HEUMA) from MAAH and 2-hydroxyethylurea

[0203] [ka] 30 g (0.5 mol) of 2-hydroxyethyl urea was added to 120 g of THF, and 0.67 g (0.005 mol) of triethylamine and 0.58 g (0.005 mol) of cross-linked polyvinylpyridine (2%) were added to the reaction vessel. The reaction mixture was stirred at 60°C until the urea was completely dissolved. Next, 42.2 g (0.274 mol) of methacrylic anhydride (MAAH) was added to the reaction vessel, and the reaction mixture was stirred at 50°C for 10 hours. After the reaction mixture was cooled, the THF was filtered and evaporated, and 72 g of DOWANOL™ PM (available from The Dow Chemical Company, Midland, MI) was added to it. The product with a dry content of 50% was used as is. The product was 1 The resulting product was analyzed by H-NMR. 1 The H-NMR spectrum is shown in Figure 3.

[0204] Example 5 Synthesis of bis-urea methacrylamide from MAAH and (bis-urea DETA) of Example 3

[0205] [ka] 10 g (0.053 mol) of bis-urea DETA (from Example 3) was added to 40 g of THF. The reaction mixture was stirred at 50°C until the bis-urea was completely dissolved. Next, 8.15 g (0.053 mol) of methacrylic anhydride (MAAH) was added to the reaction vessel, and the reaction mixture was subsequently stirred at 50°C for 10 hours. After the reaction mixture was cooled, the THF was filtered and evaporated, and 18.2 g of DOWANOL™ PM was added to it. The product with a dry content of 50% was used as is. The product was 1 The resulting product was analyzed by H-NMR. 1 The H-NMR spectrum is presented herein (Figure 4).

[0206] Example 6 Synthesis of N,N'-disubstituted urea diols from monoethanolamine and urea

[0207] [ka] 30 g (0.5 moles) of urea was added to 61 g (0.05 moles) of monoethanolamine in a reaction vessel, and the reaction mixture was heated at 100° C. for 3 hours, followed by 120° C. for an additional 3 hours. The reaction mixture was then cooled, resulting in the crystallization of the product. 1 The product was analyzed by H-NMR and used as is without further purification. The H-NMR spectrum of the product is shown in Figure 5.

[0208] Example 7 Synthesis of N,N-disubstituted urea diols from diethanolamine and urea

[0209] [ka] 30 g (0.5 mole) of urea was added to 52.5 g (0.5 mole) of diethanolamine in a reaction vessel, and the reaction mixture was heated at 100° C. for 3 hours, followed by 120° C. for an additional 3 hours. The reaction mixture was then cooled, resulting in the crystallization of the product, which was 1 The product was analyzed by H-NMR and used directly without further purification. The H-NMR spectrum of the product is shown in Figure 6.

[0210] Example 8 Synthesis of monosubstituted urea diacids from hydroxyethyl urea and trimellitic anhydride (TMA)

[0211] [ka] 27.1 g (0.2602 mol) of 2-hydroxyethyl urea, 50 g (0.2602 mol) of trimellitic anhydride, and 231 g of THF were placed in a 500 mL reaction vessel, and the reaction mixture was stirred at 60°C. Next, 0.77 g of DMAP was added to the reaction vessel, followed by stirring at 60°C for 10 hours. Next, the reaction mixture was cooled. The product was precipitated from the reaction mixture by adding 300 g of dichloromethane thereto. The product was recovered by filtration and drying. The reaction procedure described yielded the product as a white powder in a yield of 69 g (90%). 1 The product was analyzed by H-NMR. 1 The H-NMR spectrum is shown in Figure 7.

[0212] Example 9 Synthesis of dimethyl acetal methacrylamide from MAAH and aminoacetaldehyde dimethyl acetal.

[0213] [ka] 70 g (0.67 mol) of aminoacetaldehyde dimethyl acetal and 300 g of dichloromethane were placed in a 500 mL reaction vessel under constant stirring. 102.64 g (0.67 mol) of methacrylic anhydride (MAAH) was added to the reaction vessel, and the reaction mixture was stirred at 50°C for 10 hours. The reaction mixture was then cooled and placed in a settling ampoule. 100 mL of a basic aqueous solution was added to remove the acrylic acid, followed by a neutral aqueous rinse. The solvent was removed to give the product as a pure viscous liquid in 95% yield. 1 The product was analyzed by H-NMR. 1 The H-NMR spectrum is shown in Figure 8.

[0214] Example 10 Synthesis of polyacetals from polyacrylates and aminoacetaldehyde dimethyl acetals.

[0215] [ka] 10 g (0.021 mol) of di(trimethylolpropane)tetraacrylate, 9 g (0.086 mol) of aminoacetaldehyde dimethyl acetal, and 19 g of DOWANOL™ PM were placed in a 100 mL reaction vessel, and the reaction mixture was stirred at 50° C. for 10 hours. The resulting product was used as is without further purification. The reaction product was obtained in a 50% yield on dry content. 1 The product was analyzed by H-NMR. 1 The H-NMR spectrum is shown in Figure 9.

[0216] Example 11 Synthesis of polyacetals from trimethylolpropane ethoxylate triacrylate and aminoacetaldehyde dimethyl acetal.

[0217] [ka] 45.06 g of aminoacetaldehyde dimethyl acetal was placed in a reaction vessel equipped with a condenser, a stirrer, and a temperature probe. 42.33 g of trimethylolpropane ethoxylate triacrylate was slowly added to the reaction vessel over 10 minutes at room temperature to control the exotherm. The reaction mixture was then stirred at 60° C. for 6 hours.

[0218] Example 12 Synthesis of polyacetals from bisphenol A diglycidyl ether (BADGE) and aminoacetaldehyde dimethyl acetal.

[0219] [ka] 20 g (0.107 mol epoxy) of bisphenol A diglycidyl ether (BADGE), 11.44 g (0.109 mol) of aminoacetaldehyde dimethyl acetal, and 31.4 g of DOWANOL™ PM were placed in a 250 mL reaction vessel, and the reaction mixture was stirred at 50° C. for 10 hours. The resulting reaction mixture with a dry content of 50% was used as is. The reaction crude product was 1 The crude reaction product was analyzed by H-NMR. 1 The H-NMR spectrum is shown in Figure 10.

[0220] Example 13 Synthesis of polyacetals from itaconic acid and aminoacetaldehyde dimethyl acetal.

[0221] [ka] 40 g (0.253 mol) of dimethyl itaconate and 79.8 g (0.253 mol) of aminoacetaldehyde dimethyl acetal were placed in a reaction vessel, and the reaction mixture was heated to 60°C with stirring. Once the temperature reached 60°C, 0.125 g (0.3 wt%) of sodium methoxide was added to the reaction vessel. The reaction vessel was then placed under a vacuum of 120 mmHg for 10 hours. The product was obtained as a pure viscous liquid and was used as is without further purification. The crude reaction product was 1 The H-NMR spectrum is shown in FIG.

[0222] Example 14 Synthesis of polyacetals from imidazolidone and glyoxal dimethyl acetal.

[0223] [ka] 5 g (0.058 mol) of 2-imidazolidone and 9 g of DOWANOL™ PM were placed in a 100 mL reaction vessel, and the reaction mixture was stirred at 50° C. until the 2-imidazolidone was completely dissolved. Next, 20 g (0.115 mol) of glyoxal dimethyl acetal and 0.25 g of K-cure (1 wt %) were added to the reaction vessel, and the reaction mixture was subsequently stirred at 50° C. for 10 hours. The product, with a dry content of 50%, was used as is without further purification.

[0224] Example 15 Synthesis of polyacetals from polycyclocarbonates and aminoacetaldehyde dimethyl acetal.

[0225] [ka] 10 g (0.095 mol) of aminoacetaldehyde dimethyl acetal, 10.4 g (0.0478 mol) of diglycerol dicyclocarbonate, and 20.4 g of DOWANOL™ PM were placed in a 100 mL reaction vessel, and the reaction mixture was stirred at 50° C. for 10 hours. The product, with a dry content of 50%, was used as is without further purification. The crude reaction product was 1 The H-NMR spectrum is shown in FIG.

[0226] Example 16 Radical copolymerization of 25% UMA in solvent-based acrylic resins. 210 g of butyl glycol was placed in a reaction vessel equipped with a condenser, stirrer, and temperature probe and stirred at 115°C under an inert nitrogen atmosphere. A mixture of 277.2 g of 25% UMA, 37.8 g of methacrylic acid, and 9.45 g of TRIGONOX® 21S (available from Nouryon Functional Chemicals BV, Radnor, PA) was added slowly and steadily to the reaction vessel over a period of 2 hours. The reaction mixture was then stirred at 115°C for 3 hours, followed by the addition of 105 g of distilled water to reach a nonvolatile content of 50%. This resulted in an acrylic resin with a urea equivalent to solids of 900.9 and an acid value of 78.2.

[0227] Example 17 Radical copolymerization of hydroxypropyl carbamate acrylate in solvent-based acrylic resins. 210 g of butyl glycol was placed in a reaction vessel equipped with a condenser, stirrer, and temperature probe and stirred at 115°C under an inert nitrogen atmosphere. A mixture of 60.6 g of hydroxypropyl carbamate acrylate, 216.6 g of methyl methacrylate, 37.8 g of methacrylic acid, and 9.45 g of TRIGONOX® 21S was added slowly and steadily to the reaction vessel over a period of 2 hours. The reaction mixture was then stirred at 115°C for 2 hours, followed by the addition of 105 g of butyl glycol to reach a nonvolatile content of 50%. This resulted in an acrylic resin with a carbamate equivalent weight of 900.0 on a solids basis and an acid value of 78.2.

[0228] Example 18 Radical copolymerization of hydroxyethyl urea methacrylate HEUMA (Example 4) in solvent-based acrylic resins 210 g of butyl glycol was placed in a reaction vessel equipped with a condenser, stirrer, and temperature probe and stirred at 115°C under an inert nitrogen atmosphere. A mixture of 60.2 g of hydroxyethyl urea methacrylate (HEUMA) (from Example 4), 217 g of methyl methacrylate, 37.8 g of methacrylic acid, and 9.45 g of TRIGONOX® 21S was added slowly and steadily to the reaction vessel over a period of 2 hours. The reaction mixture was then stirred at 115°C for 2 hours, followed by the addition of 105 g of distilled water to reach a nonvolatile content of 50%. This resulted in an acrylic resin with a urea equivalent to solids of 900.5 and an acid value of 78.2.

[0229] Example 19 Radical copolymerization of dimethyl acetal methacrylamide (Example 9) in solvent-based acrylic resins. 168 g of butyl glycol was placed in a reaction vessel equipped with a condenser, stirrer, and temperature probe and stirred at 115°C under an inert nitrogen atmosphere. A mixture of 48.4 g of dimethyl acetal methacrylamide (from Example 9), 188.1 g of methyl methacrylate, 15.5 g of methacrylic acid, and 7.56 g of TRIGONOX® 21S was added slowly and steadily to the reaction vessel over a period of 2 hours. The reaction mixture was continued to be stirred at 115°C for 4 hours, followed by the addition of 84 g of butyl glycol to reach a nonvolatile content of 50%. The resulting acrylic resin had an aldehyde equivalent weight of 901.5 on a solids basis and an acid value of 40.1.

[0230] Example 20 Comparative Coating Evaluation of Examples 16, 17, and 18 Example 20a 24 g (0.013 urea equivalents) of the acrylic resin of Example 16, 15 g of butyl glycol, and 1.01 g (0.013 aldehyde equivalents) of a mixture of 1,3-cyclohexanedicarboxaldehyde and 1,4-cyclohexanedicarboxaldehyde (PARALOID™ EDGE XL-195, available from Parmer Holland, Westlake, OH) were mixed together. The acid functionality was neutralized with 1.41 g of dimethylethanolamine (DMEA). The resulting formulation was applied to a metal panel at a dry film thickness of 10 microns and rubbed with solvent (MEK) until the metal was revealed. The MEK test results are summarized in Table 3.

[0231] Example 20b 24 g (0.013 carbamate equivalents) of the acrylic resin of Example 17, 15 g of butyl glycol, and 1.01 g (0.013 aldehyde equivalents) of a mixture of 1,3-cyclohexanedicarboxaldehyde and 1,4-cyclohexanedicarboxaldehyde (PARALOID™ EDGE XL-195) were mixed together. The resulting formulation was applied to a metal panel at a dry film thickness of 10 microns. MEK test results are summarized in Table 3.

[0232] Example 20c 19.2 g (0.011 urea equivalents) of the acrylic resin of Example 18, 23 g of butyl glycol, and 0.80 g (0.011 aldehyde equivalents) of a mixture of 1,3-cyclohexanedicarboxaldehyde and 1,4-cyclohexanedicarboxaldehyde (PARALOID™ EDGE XL-195) were mixed together. The resulting formulation was applied to a metal panel at a dry film thickness of 10 microns. MEK test results are summarized in Table 3.

[0233] [Table 3]

[0234] Example 21 Evaluation of the Coating of Example 19 15 g (0.008 acetal equivalent) of the acrylic resin of Example 19, 7 g of butyl glycol, and 0.3 g (0.004 urea equivalent) of glycoluril were mixed together. The resulting formulation was applied to a metal panel at a dry film thickness of 10 microns. MEK test results are summarized in Table 4.

[0235] [Table 4]

[0236] Example 22 Comparative Coating Evaluation of Examples 11, 12, 13, and 14

[0237] Example 22a 2.45 g (0.01 acetal equivalent) of the acrylic resin of Example 11, 5 g of butyl acetate, and 18 g (0.01 urea equivalent) of a ureidomethacrylate-functionalized acrylic resin were mixed together. The ureidomethacrylate-functionalized acrylic resin used was synthesized in DOWANOL™ PM and had a 50% solids weight, a urea equivalent to solids of 900.9, and an acid number of 20.1. After catalyzing with 1% paratoluenesulfonic acid, the resulting formulation was applied to a metal panel at a dry film thickness of 10 microns. MEK test results are summarized in Table 5.

[0238] [Table 5]

[0239] Example 22b Five grams (0.009 acetal equivalents) of the ureidomethacrylate-functionalized acrylic resin from Example 12, 8 grams of butyl acetate, and 16.5 grams (0.009 urea equivalents) of the ureidomethacrylate-functionalized acrylic resin were mixed together. The ureidomethacrylate-functionalized acrylic resin used was synthesized in DOWANOL™ PM and had a 50% solids weight, a urea equivalent to solids of 900.9, and an acid number of 20.1. Catalyzed with 1% paratoluenesulfonic acid, the resulting formulation was applied to a metal panel at a dry film thickness of 10 microns. MEK test results are summarized in Table 6.

[0240] [Table 6]

[0241] Example 22c 2.26 g (0.017 acetal equivalents) of the ureidomethacrylate-functionalized acrylic resin from Example 13, 16.71 g of DOWANOL™ PM, and 30 g (0.017 urea equivalents) of the ureidomethacrylate-functionalized acrylic resin were mixed together. The ureidomethacrylate-functionalized acrylic resin used was synthesized in DOWANOL™ PM and had a solids weight of 50%, a urea equivalent to solids of 900.9, and an acid number of 20.1. The resulting formulation was applied to a metal panel at a dry film thickness of 8.5 microns. MEK test results are summarized in Table 7.

[0242] [Table 7]

[0243] Example 21d 4 g (0.014 acetal equivalents) from Example 14, 8 g butyl acetate, and 24.8 g (0.014 urea equivalents) of ureidomethacrylate-functionalized acrylic resin were mixed together. The ureidomethacrylate-functionalized acrylic resin used was synthesized in DOWANOL™ PM and had a 50% weight solids content, a 900.9 urea equivalent to solids content, and an acid number of 20.1. Catalyzed with 1% paratoluenesulfonic acid, the resulting formulation was applied to a metal panel at a dry film thickness of 10 microns, and the MEK test results are summarized in Table 8.

[0244] [Table 8]

[0245] Example 23 Furanaldehyde was synthesized from 5,5'-[oxybis(methylene)]di-(2-furaldehyde).

[0246] [ka] 10 g (0.079 mol) of hydroxymethylfurfural (HMF) and 100 mL of dichloromethane were placed in a reaction vessel equipped with a condenser, a stirrer, and a temperature probe, and the mixture was stirred under an inert argon atmosphere. A mixture of 0.5 g of trifluoromethanesulfonic acid (triflic acid) and 10 mL of dichloromethane was added dropwise to the reaction vessel at 0 °C, and the temperature was maintained at 0 °C during the addition. After completion of the reaction, the organic phase was washed with 100 mL of water, followed by a second wash with 50 mL of water. The resulting organic phase was dried over anhydrous sodium sulfate. After removing the solids by filtration, the dichloromethane was removed by distillation, and the HMF was removed under vacuum. The resulting product was 1 The product was analyzed by H-NMR, and the spectrum showed that it contained 5% residual HMF.

[0247] Example 24 Preparation of hydroxymethylfurfural (HMF) methacrylate monomer

[0248] [ka] 100 g (0.793 mol) of hydroxymethylfurfural (HMF), 635.1 g of methyl methacrylate, and 0.7 g (0.0032 mol) of hydroquinone were placed in a reaction vessel equipped with a Dean-Stark receiver. The mixture was stirred at 100°C for 30 minutes to remove traces of water. 11.6 g of zirconium acetylacetonate was added to the reaction vessel, and the reaction mixture was stirred at 100°C for 10 hours. During this time, distillate containing methanol was periodically removed from the Dean-Stark receiver. The reaction mixture was then stirred at 100°C for 10 hours. -2 Methyl methacrylate was removed by distillation under a vacuum of 100 mbar at a temperature of 70°C. The product was redissolved in dichloromethane and washed three times with aqueous potassium bicarbonate. After a final wash with saturated aqueous brine, the organic phase was dried over anhydrous sodium sulfate. After filtration to remove the solids, the solvent was removed for 10 minutes. -2The reaction was carried out under vacuum at 1000 mbar and at 70° C. The reaction procedure described gave the product as a viscous brown liquid in a yield of 139 g (90%). 1 H-NMR helped characterize it as HMF methacrylate. 1 H-NMR is shown in Figure 13.

[0249] All references and publications cited herein are expressly incorporated by reference in their entirety into this disclosure, except to the extent they may directly contradict this disclosure. While specific embodiments have been illustrated and described herein, those skilled in the art will understand that various alternative and / or equivalent implementations may be substituted for the specific embodiments illustrated and described without departing from the scope of the present disclosure. It is understood that this disclosure is not intended to be unduly limited by the exemplary embodiments and examples set forth herein, and that such examples and embodiments are presented by way of example only, with the scope of the present disclosure intended to be limited only by the claims set forth herein.

Claims

1. urea component, aldehydes containing two or more carbon atoms, and a coating system comprising:

2. 10. The coating system of claim 1, wherein the urea component is present in a molar ratio of 0.5 to 2.5 moles per mole of the aldehyde.

3. The urea component is represented by the following formula (I): 【Chemistry 1】 In the formula, R １ , R ２ , R ３ , and R ４ are independently H or a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R １ , R ２ , R ３ , and R ４ is independently H or an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group; R １ , R ２ , R ３ , and R ４ at least one of is H; R １ , R ２ , R ３ , and R ４ 3. The coating system of claim 1 or 2, wherein any two of may be connected to each other to form a cyclic group.

4. The coating system of any one of claims 1 to 3, wherein the urea component is part of an oligomer containing multiple unsubstituted or substituted urea functional groups.

5. The aldehyde is represented by the following formula (II) or formula (IIA): 【Chemistry 2】 In the formula, R ５ , R ６ , and R ７ are independently carbon-containing groups optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or combinations thereof, and preferably R ５ , R ６ , and R ７ is independently an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group, and optionally the aldehyde is in a protected form, including an acetal or hydrate.

6. The coating system of any one of claims 1 to 5, wherein the aldehyde comprises a monoaldehyde.

7. The coating system of any one of claims 1 to 6, wherein the aldehyde comprises a polyaldehyde.

8. The coating system according to any one of claims 1 to 7, wherein the aldehyde is an oligomer.

9. The urea component and the aldehyde form a reaction product represented by formula (III): 【Transformation 3】 In the formula, R １ is a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R １ is an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group; R ５ The coating system according to any one of claims 1 to 8, wherein is the same as formula (II).

10. The urea component and the aldehyde form a further reaction product represented by formula (IV): 【Chemistry 4】 In the formula, R １ is a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R １ is an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group; R ５ The coating system according to any one of claims 1 to 9, wherein is the same as formula (II).

11. The coating system of any one of claims 1 to 10, wherein the coating system is free or substantially free of formaldehyde.

12. The coating system of any one of claims 1 to 11, wherein the coating system is free or substantially free of isocyanates.

13. 13. The coating system of any one of claims 1 to 12, wherein the coating system is curable at a temperature of 60°C or less, 50°C or less, 40°C or less, 30°C or less, or 25°C or less.

14. Urea component, and an aldehyde containing two or more carbon atoms.

15. The reaction product is a crosslinked product of formula (III): 【Transformation 5】 In the formula, R １ is a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R １ is an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group; R ５ 15. The coating system of claim 14, wherein is the same as formula (II).

16. The reaction product is a crosslinked product of formula (IV): 【Transformation 6】 In the formula, R １ is a carbon-containing group optionally further substituted with one or more oxygen, nitrogen, or sulfur atoms, or a combination thereof, and preferably R １ is an alkyl, aryl, acyl, acrylate, carboxylic acid, urethane, ester, amide, carbonate, alkenyl, alkynyl, alkoxy, alcohol, amine, alkylamine, methacrylate, acrylamide, methacrylamide, vinyl, phenol, ketone, or urea group; R ５ 16. The coating system of claim 14 or 15, wherein is the same as formula (II).

17. The coating system of any one of claims 14 to 16, wherein the coating system is in powder form.

18. The coating system of any one of claims 14 to 17, wherein the coating system comprises an organic solvent, water, or both.

19. 19. The coating system of any one of claims 14 to 18, wherein the coating system is free or substantially free of formaldehyde or structural units derived from formaldehyde.

20. 20. The coating system of any one of claims 14 to 19, wherein the coating system is free or substantially free of isocyanates or structural units derived from isocyanates.

21. The coating system of claim 5 , wherein the coating system is provided as a one-component coating and the aldehyde comprises a blocked aldehyde.

22. 22. The coating system of claim 21, wherein the protected aldehyde comprises an acetal or a hydrate.

23. 10. The coating system of claim 1, wherein the aldehyde is a protected aldehyde including an acetal or a hydrate.

24. 8. The coating system of claim 7, wherein the aldehyde comprises a polyaldehyde selected from the group consisting of terephthalaldehyde, glutaraldehyde, glyoxal, dimethoxyacetaldehyde, methylglyoxal, cyclohexane dicarbaldehyde, malondialdehyde bis(dimethyl acetal), 5,5'-(oxy-bis(methylene))bis-2-furfural, bis(dimethyl acetal) of imidazolidone, tetra-dimethyl acetal of glycoluril, bis(dimethyl acetal) of polyglycidyl ether, tri(aminoethyl dimethyl acetal) of itaconic acid, tri(aminoethyl dimethyl acetal) of TMPEOTA, or poly(dimethyl acetal) of polycyclocarbonate.

25. R on the acetal of formula (IIA) ６ Groups and R ７ 23. The coating system of claim 22, wherein the groups are the same.

26. 23. The coating system of claim 22, wherein the protected aldehyde comprises a cyclic acetal.

27. An article coated with the coating system of any one of claims 1 to 26.

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